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  • 101.
    Abbass, Allan
    et al.
    Dalhousie University, Canada.
    Johansson, Robert
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Rasic, Daniel
    Dalhousie University, Canada.
    Town, Joel M.
    Dalhousie University, Canada.
    Johansson, Robert
    Linköping University, Department of Behavioural Sciences and Learning, Psychology. Linköping University, Faculty of Arts and Sciences.
    Long-term healthcare cost reduction with Intensive Short-term Dynamic Psychotherapy in a tertiary psychiatric service2015In: Journal of Psychiatric Research, ISSN 0022-3956, E-ISSN 1879-1379, Vol. 64, 114-120 p.Article in journal (Refereed)
    Abstract [en]

    Objective: To evaluate whether a mixed population of patients treated with Intensive Short-term Dynamic Psychotherapy (ISTDP) would exhibit reduced healthcare costs in long-term follow-up. Methods: A quasi-experimental design was employed in which data on pre- and post-treatment healthcare cost were compared for all ISTDP cases treated in a tertiary care service over a nine year period. Observed cost changes were compared with those of a control group of patients referred but never treated. Physician and hospital costs were compared to treatment cost estimates and normal population cost figures. Results: 1082 patients were included; 890 treated cases for a broad range of somatic and psychiatric disorders and 192 controls. The treatment averaged 7.3 sessions and measures of symptoms and interpersonal problems significantly improved. The average cost reduction per treated case was $12,628 over 3 follow-up years: this compared favorably with the estimated treatment cost of $708 per patient. Significant differences were seen between groups for follow-up hospital costs. Conclusions: ISTDP in this setting appears to facilitate reductions in healthcare costs, supporting the notion that brief dynamic psychotherapy provided in a tertiary setting can be beneficial to health care systems overall. (C) 2015 Elsevier Ltd. All rights reserved.

  • 102.
    Abbatelli, Daniele
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, The Institute of Technology.
    Material flows in the waterjet industry: an environmental perspective2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Abrasive Waterjet cutting (AWJ) presents many advantages over competing machining techniques, but several issues are related to the high volume of materials (and in particular of abrasive) used in the process.

    In this study, the environmental impact of the material flows in the abrasive waterjet industry has been analyzed adopting a life cycle perspective in order to individuate which phases place the largest burden on the environment. Moreover, three alternative abrasives (crushed rock, recycled glass and synthetic abrasive) and three disposal practices (in-site recycling, off-site recycling and recycling as construction material) have been also evaluated to estimate the benefits that can be achieved if these could be used in place of garnet abrasives and landfilling.

    The transportation of the abrasive resulted to be the phase that has the largest influence in every case and thus should be reduced as much as possible. For what concerns the alternative options, the usage of recycled glass and the in-site recycling of the abrasive were the two alternatives with the best environmental performances. However, crushed rock could be the best option for what concerns the global warming potential if carbon sequestration due to carbonation of silicate rocks is taken into account. Off-site recycling and recycling as construction material are good options only if the transportation to the recycling site can be reduced. Synthetic abrasive are instead found to have a much larger impact compared to every other alternative examined.

  • 103.
    Abbey, Susan E.
    et al.
    University of Toronto, Canada.
    De Luca, Enza
    University Health Network, University of Toronto, Canada.
    Mauthner, Oliver E.
    University Health Network, University of Toronto, Canada.
    McKeever, Patricia
    Bloorview Research Institute, Bloorview Kids Rehab, Canada.
    Shildrick, Margrit
    Queen's University, Belfast, Northern Ireland.
    Poole, Jennifer M.
    Ryerson University, Canada.
    Gewarges, Mena
    University Health Network, University of Toronto, Canada.
    Ross, Heather J.
    University Health Network, University of Toronto, Canada.
    Qualitative interviews versus standardised self-report questionnaires in assessing qualityb of life in heart transplant recipients2011In: The Journal of Heart and Lung Transplantation, ISSN 1053-2498, Vol. 30, no 8, 963-966 p.Article in journal (Refereed)
    Abstract [en]

    Quality of life (QoL) studies in heart transplant recipients (HTRs) using validated, quantitative, self-report questionnaires have reported poor QoL in approximately 20% of patients. This consecutive mixed methods study compared self-report questionnaires, the Medical Outcomes Study 36-item Short Form Health Survey (MOS SF-36) and the Atkinson Life Satisfaction Scale, with phenomenologically informed audiovisual (AV) qualitative interview data in 27 medically stable HTRs (70% male; age 53 ± 13.77 years; time since transplant 4.06 ± 2.42 years). Self-report questionnaire data reported poor QoL and more distress compared with previous studies and normative population samples; in contrast, 52% of HTRs displayed pervasive distress according to visual methodology. Using qualitative methods to assess QoL yields information that would otherwise remain unobserved by the exclusive use of quantitative QOL questionnaires.

  • 104.
    Abbott, Allan
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Medicine and Health Sciences. Faculty of Health Science and Medicine, Bond University, Gold Coast, Queensland, Australia.
    Evidence base and future research directions in the management of low back pain2016In: World Journal of Orthopedics, ISSN 2218-5836, E-ISSN 2218-5836, Vol. 7, no 3, 156-161 p.Article in journal (Other academic)
    Abstract [en]

    Low back pain (LBP) is a prevalent and costly condition. Awareness of valid and reliable patient history taking, physical examination and clinical testing is important for diagnostic accuracy. Stratified care which targets treatment to patient subgroups based on key characteristics is reliant upon accurate diagnostics. Models of stratified care that can potentially improve treatment effects include prognostic risk profiling for persistent LBP, likely response to specific treatment based on clinical prediction models or suspected underlying causal mechanisms. The focus of this editorial is to highlight current research status and future directions for LBP diagnostics and stratified care.

  • 105.
    Abbott, Allan
    Department of Clinical Sciences, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden.
    Physiotherapeutic rehabilitation and lumbar fusion surgery2010Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Over the last two decades, the economic costs and rates of lumbar fusion surgery for chronic low back pain has risen dramatically in western industrialized countries. Data from the Swedish National Spine Register suggest that 25% of patients experience unimproved pain and up to 40% are not satisfied with the outcome of lumbar fusion surgery. Thus, there is a definite need to optimize the selection and management of patients to improve lumbar fusion outcomes. Aim: To investigate the role of biopsychosocial factors in explaining disability and health related quality of life in chronic low back pain patients before and after lumbar fusion surgery and to evaluate the effectiveness of post-operative rehabilitation regimes. Methods: At total of 107 patients were recruited, aged 18 to 65 years, selected for lumbar fusion due to 12 months of symptomatic back and/or leg pain due to spinal stenosis, degenerative/isthmic spondylolisthesis or degenerative disc disease. Measures of disability, health related quality of life, pain, mental health, fear of movement/(re)injury, self-efficacy, outcome expectancy, pain coping styles, work status, health care use, analgesic use and sickness leave were collected with self-rated questionnaires at baseline (Studies I-IV), 3, 6, 12 months (Study II) and 2-3 years after surgery (Studies II-III). In Studies II-IV, patients were randomised to psychomotor therapy (N=53) or exercise therapy (N=54) implemented during the first 3 post-operative months. Semi-structured interviews were conducted 3-6 months after surgery on 20 patients including 10 from each rehabilitation group to investigate experiences of back problems before and after surgery, post-operative recovery and expectations of rehabilitation analysed in terms of the International Classification of Functioning, Disability and Health (Study IV). Results: Approximately 50% of the variability in baseline disability and 40% of the variability in baseline health related quality of life could be explained by psychological variables. In particular, catastrophizing, control over pain, self-efficacy and outcome expectancy had significant mediation roles (Study I). For the short and long term outcome of lumbar fusion surgery, post-operative psychomotor therapy is significantly more effective than exercise therapy with approximately 10-20% better outcome in measures of disability, fear of movement/(re)injury, pain catastrophizing, self-efficacy, outcome expectancy sickness leave, health care utilization and return to work (Study II). A model with good outcome predictive performance which significantly predicts disability, back pain and health related quality of life outcomes 2-3 year after lumbar fusion surgery, was shown to involve pre-operative screening of disability, leg pain intensity, mental health, fear of movement/(re)injury, outcome expectations, catastrophizing, control over pain and the implementation of post-operative psychomotor therapy (Study III). Lumbar fusion patient s experiences of back problems before and after the operation as well as experiences of recovery and outcome expectations correspond well with the content of outcomes measures used in the study suggesting good content validity (Study IV). Conclusion: Psychological factors strongly influence levels of disability and health related quality of life in lumbar fusion candidates as well as predicts post-operative outcomes. Early post-operative rehabilitation focusing on cognition, behaviour and motor control is recommended for improved lumbar fusion outcomes.

  • 106.
    Abbott, Allan
    Karolinska Institute, Sweden.
    The Coping Strategy Questionnaire2010In: Journal of Physiotherapy, ISSN 1836-9553, E-ISSN 1836-9561, Vol. 56, no 1, 63-63 p.Article in journal (Other academic)
  • 107.
    Abbott, Allan
    et al.
    Department of Physical Therapy, Neuro R1:07, Karolinska University Hospital, Stockholm, Sweden; Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institute, Huddinge, Sweden; Institute of Health and Sport, Bond University, Queensland, Australia.
    Ghasemi-Kafash, Elaheh
    Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institute, Huddinge, Sweden.
    Dedering, Åsa
    Department of Physical Therapy, Neuro R1:07, Karolinska University Hospital, Stockholm, Sweden; Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society (NVS), Karolinska Institute, Huddinge, Sweden.
    The validity of using an electrocutaneous device for pain assessment in patients with cervical radiculopathy2014In: Physiotherapy Theory and Practice, ISSN 0959-3985, E-ISSN 1532-5040, Vol. 30, no 7, 500-506 p.Article in journal (Refereed)
    Abstract [en]

    The purpose of this study was to evaluate the validity and preference for assessing pain magnitude with electrocutaneous testing (ECT) compared to the visual analogue scale (VAS) and Borg CR10 scale in men and women with cervical radiculopathy of varying sensory phenotypes. An additional purpose was to investigate ECT sensory and pain thresholds in men and women with cervical radiculopathy of varying sensory phenotypes. This is a cross-sectional study of 34 patients with cervical radiculopathy. Scatterplots and linear regression were used to investigate bivariate relationships between ECT, VAS and Borg CR10 methods of pain magnitude measurement as well as ECT sensory and pain thresholds. The use of the ECT pain magnitude matching paradigm for patients with cervical radiculopathy with normal sensory phenotype shows good linear association with arm pain VAS (R(2) = 0.39), neck pain VAS (R(2) = 0.38), arm pain Borg CR10 scale (R(2) = 0.50) and neck pain Borg CR10 scale (R(2) = 0.49) suggesting acceptable validity of the procedure. For patients with hypoesthesia and hyperesthesia sensory phenotypes, the ECT pain magnitude matching paradigm does not show adequate linear association with rating scale methods rendering the validity of the procedure as doubtful. ECT for sensory and pain threshold investigation, however, provides a method to objectively assess global sensory function in conjunction with sensory receptor specific bedside examination measures.

  • 108.
    Abbott, Allan
    et al.
    Physiotherapist, Department for Physiotherapy, Karolinska University Hospital, Stockholm, Sweden.
    Halvorsen, Marie
    Physiotherapist, Department for Physiotherapy, Karolinska University Hospital, Stockholm, Sweden.
    Dedering, Åsa
    Physiotherapist, Department for Physiotherapy, Karolinska University Hospital, Stockholm, Sweden.
    Is there a need for cervical collar usage post anterior cervical decompression and fusion?: A randomized control pilot trial2013In: Physiotherapy Theory and Practice, ISSN 0959-3985, E-ISSN 1532-5040, Vol. 29, no 4, 290-300 p.Article in journal (Refereed)
    Abstract [en]

    Anterior cervical discectomy and fusion (ACDF) is a common surgical intervention for radiculopathy resulting from degenerative cervical spine conditions. Post-surgical cervical collar use is believed to reduce post-operative pain, provide the patient with a sense of security during activities of daily living and even reduce rates of non-fusion. This prospective randomized controlled pilot trial investigates trial design feasibility in relation to prospective physical, functional, and quality of life-related outcomes of patients undergoing ACDF with interbody cage, with (n = 17) and without (n = 16) post-operative cervical collar usage. Results show that the sample provides sufficient statistical power to show that the use of a rigid cervical collar during 6 post-operative weeks is associated with significantly lower levels of neck disability index after 6 weeks and significantly lower levels of prospective neck pain. To investigate causal quality of life or fusion rate outcomes, sample size needs to be increased at least fourfold and optimally sixfold when accounting for data loss in prospective follow-up. The study suggests that post-surgical cervical collar usage may help certain patients cope with initial post-operative pain and disability.

  • 109.
    Abbott, Allan
    et al.
    Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden; Department of Clinical Science, Intervention and Technology, Division of Orthopaedics, Karolinska University Hospital, Karolinska Institute, Stockholm , Sweden.
    Hedlund, Rune
    Department of Orthopaedics, Institute for Clinical Science, University of Gothenburg, Gothenburg, Sweden.
    Tyni-Lenné, Raija
    Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden.
    Patient’s experience post-lumbar fusion regarding back problems, recovery and expectations in terms of the international classification of functioning, disability and health.2011In: Disability and Rehabilitation, ISSN 0963-8288, E-ISSN 1464-5165, Vol. 33, no 15-16, 1399-1408 p.Article in journal (Refereed)
    Abstract [en]

    PURPOSE:

    To describe within the context of the International Classification of Functioning, Disability and Health (ICF), patient's experiences post-lumber fusion regarding back problems, recovery and expectations of rehabilitation and to contrast with the content of outcome measures and the ICF low back pain (LBP) core sets.

    METHODS:

    The study has a cross-sectional and retrospective design and involves 20 lumbar fusion patients. Using the ICF, qualitative content analysis of semi-structured interviews 3-6 months post-surgery was performed. This was compared with the ICF related content of the Oswestry Disability Index (ODI), Medical Outcome Study Short Form 36 (SF-36), European Quality of Life Questionnaire (EQ5D) and the ICF LBP core sets.

    RESULTS:

    Patient's experiences were most frequently linked to psychological, sensory, neuromusculoskeletal and movement related body function chapters of the ICF. The most frequently linked categories of activity and participation were mobility, domestic activities, family relationships, work, recreation and leisure. Environmental factors frequently linked were the use of analgesics, walking aids, family support, social security systems, health care systems and labour market employment services.

    CONCLUSIONS:

    This study highlights important ICF related aspects of patient's experiences post-lumber fusion. The use of the comprehensive ICF core sets is recommended in conjunction with ODI, SF-36 and the EQ5D for a broader analysis of patient outcomes post-lumbar fusion.

  • 110.
    Abbott, Allan
    et al.
    Karolinska University Hospital, Sweden; Karolinska Institute, Sweden; Bond University, Australia.
    Kjellman, Görel
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Local Health Care Services in West Östergötland, Research & Development Unit in Local Health Care.
    Peolsson, Anneli
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences.
    Multidimensional assessment of pain related disability after surgery for cervical disc disease2013In: APA Conference 2013: New moves, Australian Physiotherapy Association , 2013, 2-2 p.Conference paper (Other academic)
    Abstract [en]

    Questions: Given only 25% of patients, 10 year post-surgery for cervical disc disease report clinically meaningful improvements in functional disability, what are the biopsychosocial factors associated with continued long-term disability? What are the implications for physiotherapy practice?

    Design: Cross-sectional observational study.

    Participants: Ninety patients who had undergone anterior discectomy and fusion (ACDF) surgery 10-13 years prior.

    Outcome Measures: The Neck Disability Index (NDI), ACDF surgery type, surgical fusion status, patient age and Part 1 of the West Haven-Yale multidimensional pain inventory Swedish version (MPI-S) were entered into a statistical model. Part 1 of the MPI-S contains 5 subscales: pain severity, interference, life control, affective distress and support.

    Results: Seventy-three patients answered the questionnaires. Non-linear categorical regression modeling (CATREG) of the selected predictive variables explained 76.1% of the variance in NDI outcomes 10-13 years post ACDF. Of these predictors, MPI-S affective distress subscale (β = 0.635, p = <0.001) and pain severity subscale (β = 0.354, p = <0.001) were significant individual predictors of NDI ratings.

    Conclusion: This is the first study to investigate potential factors associated with prolonged functional disability greater than 10 years post-surgery for cervical disc disease. The results suggest the importance of not only pain severity but also screening affective distress as a potential barrier to physical functioning in patients previously operated for cervical disc disease. Future research on the utility of affect-focused body awareness therapy and pain coping strategies for post-surgical patients with continuing pain and physical disability is indicated.

    Key Practice Points:

    •  The screening of pain severity and affective distress is of importance for patients presenting with continuing physical disability after previous surgery for cervical disc disorders

    •  Affect-focused body awareness therapies and pain coping strategies may be a potential treatment alternative for patients with continuing pain and physical disability.

  • 111.
    Abbott, Allan
    et al.
    Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden; Bond University, Gold Coast, Australia.
    Möller, Hans
    Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    Gerdhem, Paul
    Karolinska Institutet, Stockholm, Sweden; Karolinska University Hospital, Stockholm, Sweden.
    CONTRAIS: CONservative TReatment for Adolescent Idiopathic Scoliosis: a randomised controlled trial protocol2013In: BMC Musculoskeletal Disorders, ISSN 1471-2474, E-ISSN 1471-2474, Vol. 14, 261Article in journal (Refereed)
    Abstract [en]

    Background:

    Idiopathic scoliosis is a three-dimensional structural deformity of the spine that occurs in children and adolescents. Recent reviews on bracing and exercise treatment have provided some evidence for effect of these interventions. The purpose of this study is to improve the evidence base regarding the effectiveness of conservative treatments for preventing curve progression in idiopathic scoliosis.

    Methods/design:

    Patients: Previously untreated girls and boys with idiopathic scoliosis, 9 to 17 years of age with at least one year of remaining growth and a curve Cobb angle of 25–40 degrees will be included. A total of 135 participants will be randomly allocated in groups of 45 patients each to receive one of the three interventions.Interventions: All three groups will receive a physical activity prescription according to the World Health Organisation recommendations. One group will additionally wear a hyper-corrective night-time brace. One group will additionally perform postural scoliosis-specific exercises.Outcome: Participation in the study will last until the curve has progressed, or until cessation of skeletal growth. Outcome variables will be measured every 6 months. The primary outcome variable, failure of treatment, is defined as progression of the Cobb angle more than 6 degrees, compared to the primary x-ray, seen on two consecutive spinal standing x-rays taken with 6 months interval. Secondary outcome measures include the SRS-22r and EQ5D-Y quality of life questionnaires, the International Physical Activity Questionnaire (IPAQ) short form, and Cobb angle atend of the study.

    Discussion:This trial will evaluate which of the tested conservative treatment approaches that is the most effective for patients with adolescent idiopathic scoliosis.

    Trial registration: NCT01761305

  • 112.
    Abbott, Allan
    et al.
    Department of Physical Therapy, Karolinska University Hospital; Department of Clinical Science, Intervention and Technology, Division of Orthopaedics, Karolinska Institute, Stockholm, Sweden.
    Tyni-Lenné, Raija
    Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden.
    Hedlund, Rune
    Department for Orthopaedics, Institute for Clinical Sciences, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Early rehabilitation targeting cognition, behaviour and motor function after lumbar fusion: A randomized controlled trial2010In: Spine, ISSN 0362-2436, E-ISSN 1528-1159, Vol. 35, no 8, 848-857 p.Article in journal (Refereed)
    Abstract [en]

    Study Design - Open label randomized controlled trial with 3-, 6-, 12-month, and 2- to 3-year follow-up.

    Objective - To investigate the effectiveness of a psychomotor therapy focusing on cognition, behavior, and motor relearning compared with exercise therapy applied during the first 3 months after lumbar fusion.

    Summary of Background Data - Postoperative management after lumbar fusion commonly focuses on analgesic pain control and activities of daily living. After 3 months, exercise therapy is often implemented. No randomized controlled trial has investigated early rehabilitation techniques conducted during the first 3 months after surgery.

    Methods - The study recruited 107 patients, aged 18 to 65 years, selected for lumbar fusion because of 12 months of symptomatic spinal stenosis, spondylosis, degenerative/isthmic spondylolisthesis, or degenerative disc disease. The exercise therapy group received a home program focusing on pain contingent training of back, abdominal, and leg muscle functional strength and endurance, stretching, and cardiovascular fitness. The psychomotor therapy group received a home program and 3 outpatient sessions focusing on modifying maladaptive pain cognitions, behaviors, and motor control. Rated questionnaires investigating functional disability, pain, health-related quality of life, functional self-efficacy, outcome expectancy, fear of movement/(re)injury, and coping were assessed at 3, 6, 12 months, and 2 to 3 years after surgery.

    Results - Follow-up rates were 93% at 12 months and 81% at 2 to 3 years after surgery. Psychomotor therapy improved functional disability, self-efficacy, outcome expectancy, and fear of movement/(re)injury significantly more than exercise therapy at respective follow-up occasions. Similar results occurred for pain coping but group differences were nonsignificant at 2 to 3 years follow-up. Potentially clinical relevant higher reoperation rates occurred after psychomotor therapy but rates were within normal ranges.

    Conclusion - The study shows that postoperative rehabilitation can be safely implemented during the first 3 months after lumbar fusion and should include measures to modify psychological as well as motor functions.

  • 113.
    Abbott, Allan
    et al.
    Linköping University, Department of Medical and Health Sciences, Division of Physiotherapy. Linköping University, Faculty of Health Sciences. Department of Physical Therapy, Karolinska University Hospital, Huddinge, Stockholm, Sweden; Division of Orthopaedics, Department of Clinical Science, Intervention and Technology, Karolinska Institute, Stockholm, Sweden.
    Tyni-Lenné, Raija
    Department of Physical Therapy, Karolinska University Hospital, Huddinge, Stockholm, Sweden; Division of Physiotherapy, Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Stockholm, Sweden.
    Hedlund, Rune
    Department for Orthopaedics, Institute for Clinical Sciences, Sahlgrenska University Hospital, Gothenburg, Sweden.
    Leg pain and psychological variables predict outcome 2-3 years after lumber fusion surgery2011In: European spine journal, ISSN 0940-6719, E-ISSN 1432-0932, Vol. 20, no 10, 1626-1634 p.Article in journal (Refereed)
    Abstract [en]

    Prediction studies testing a thorough range of psychological variables in addition to demographic, work-related and clinical variables are lacking in lumbar fusion surgery research. This prospective cohort study aimed at examining predictions of functional disability, back pain and health-related quality of life (HRQOL) 2-3 years after lumbar fusion by regressing nonlinear relations in a multivariate predictive model of pre-surgical variables. Before and 2-3 years after lumbar fusion surgery, patients completed measures investigating demographics, work-related variables, clinical variables, functional self-efficacy, outcome expectancy, fear of movement/(re)injury, mental health and pain coping. Categorical regression with optimal scaling transformation, elastic net regularization and bootstrapping were used to investigate predictor variables and address predictive model validity. The most parsimonious and stable subset of pre-surgical predictor variables explained 41.6, 36.0 and 25.6% of the variance in functional disability, back pain intensity and HRQOL 2-3 years after lumbar fusion. Pre-surgical control over pain significantly predicted functional disability and HRQOL. Pre-surgical catastrophizing and leg pain intensity significantly predicted functional disability and back pain while the pre-surgical straight leg raise significantly predicted back pain. Post-operative psychomotor therapy also significantly predicted functional disability while pre-surgical outcome expectations significantly predicted HRQOL. For the median dichotomised classification of functional disability, back pain intensity and HRQOL levels 2-3 years post-surgery, the discriminative ability of the prediction models was of good quality. The results demonstrate the importance of pre-surgical psychological factors, leg pain intensity, straight leg raise and post-operative psychomotor therapy in the predictions of functional disability, back pain and HRQOL-related outcomes.

  • 114.
    Abbott, Allan
    et al.
    Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden; Department of Clinical Science, Intervention and Technology, Division of Orthopaedics, Karolinska Institute, Stockholm, Sweden.
    Tyni-Lenné, Raija
    Department of Physical Therapy, Karolinska University Hospital, Stockholm, Sweden.
    Hedlund, Rune
    Institute for Clinical Sciences, Department for Orthopaedics, Sahlgrenska University Hospital, Gothenburg, Sweden.
    The influence of psychological factors on pre-operative levels of pain intensity, disability and HRQOL in lumbar spinal fusion surgery patients2010In: Physiotherapy, ISSN 0031-9406, E-ISSN 1873-1465, Vol. 96, no 3, 213-221 p.Article in journal (Refereed)
    Abstract [en]

    OBJECTIVES:

    To assess the extent to which perceived pain and psychological factors explain levels of disability and health-related quality of life (HRQOL) in patients scheduled for lumbar fusion surgery, and to test the hypothesis that relationships between pain intensity, mental health, fear of movement/(re)injury, disability and HRQOL are mediated by cognitive beliefs and appraisals.

    DESIGN:

    Cross-sectional, correlation study.

    SETTING:

    Orthopaedic outpatient setting in a tertiary hospital.

    PARTICIPANTS:

    One hundred and seven chronic back pain patients scheduled for lumbar fusion surgery.

    MEASURES:

    Visual analogue scale for pain intensity, Short Form 36 mental health subscale, Tampa Scale for Kinesiophobia, Back Beliefs Questionnaire, Self-efficacy Scale, Coping Strategy Questionnaire, Oswestry Disability Index and European Quality of Life Questionnaire.

    RESULTS:

    The group effect of multiple mediators significantly influenced the relationships between pain intensity and mental health, fear of movement/(re)injury, functional disability and HRQOL. Pain catastrophising significantly mediated the relationship between pain intensity and mental health, control over pain significantly mediated the relationship between mental health and functional disability, self-efficacy and pain outcome expectancy significantly mediated the relationship between mental health and HRQOL, and self-efficacy also significantly mediated the relationship between pain intensity, fear of movement/(re)jury and functional disability. The model explained 28, 30, 52 and 42% of the variation in mental health, fear of movement/(re)injury, functional disability and HRQOL, respectively.

    CONCLUSIONS:

    This study highlights the strong influence and mediation roles of psychological factors on pain, mental health, fear of movement/(re)injury, disability and HRQOL in patients scheduled for lumber fusion. Future research should focus on screening as well as pre- and post-operative interventions based on these psychological factors for the potential improvement of lumber fusion surgery outcomes.

    Copyright 2010 Chartered Society of Physiotherapy. Published by Elsevier Ltd. All rights reserved.

  • 115.
    Abbott, Allan
    et al.
    Karolinska Institute, Stockholm, Sweden.
    Tynni-Lenne, Raija
    Karolinska Institute, Stockholm, Sweden.
    Hedlund, Rune
    Karolinska Institute, Stockholm, Sweden.
    Early physiotherapeutic rehabilitation following lumbar spinal fusion surgery2009In: Oral Presentations: Cervical Spine: The Surgical Treatment of Painful Disorders, Springer, 2009, Vol. 18, Supplement 4, S409-S410 p.Conference paper (Other academic)
    Abstract [en]

    Background: Physiotherapy after lumbar spinal fusion surgery is traditionally focused on physical exercise. Too few studies have investigatedthe efficacy of modern lumbar stabilization exercise regimes. Benefits have been shown for combining traditional physical exercise with a psychosocial intervention. No randomised controlled study has evaluated thecombined biopsychosocial effect of modern lumbar stabilization exercisesand cognitive behavioural intervention compared to traditional physical exercise starting immediately after lumbar spinal fusion.

    Purpose: To investigate the effectiveness of modern physiotherapy(MPT) compared to a traditional physiotherapy (TPT) starting immediately after lumber spinal fusion.

    Study design/setting: Randomized controlled clinical trial.

    Patient sample, inclusion period and follow-up: Patients between 18 and 65 years, selected for lumbar spinal fusion due to at least 12 months of CLBP symptoms caused by spinal stenosis, spondylosis, spondylolisthesis or degenerative disc disease were included in the study between 2005 and 2007. A total of 107 patients were randomly allocated to the MPT group (n = 53) and TPT group (n = 54). The TPT group was prescribed daily home based pain contingent training of traditional physical exercises for back, abdominal and leg muscles. The MPT group was prescribed daily home based training of lumbar stabilization exercises combined with 90 min of cognitive behavioural intervention at 3, 6 and 9 weeks after the operation. The patients outcomes were followed up at 3, 6, 12 months and 2–3 years

    Outcome measures: Oswestry disability index (ODI), pain intensity, HRQOL, kinesiophobia, anxiety/depression, self-efficacy, outcome expectancy, use of coping strategies, work status, sickness leave and health care use.

    Methods: Analysis of mean differences between groups.

    Results: 2–3 year follow-up showed that the MPT group had significantly lower percentage scores in ODI = 18.2 (P = 0.008), kinesiophobia= 30.0 (P = 0.001), catastrophizing = 21.8 (P = 0.006) and higher self-efficacy = 64.6 (P = 0.019) compared to TPT group’s ODI = 28.1, kinesiophobia = 41.9, catastrophizing = 31.3 and self-efficacy = 55.5. The MPT group had significantly more employment, less health care use (P = 0.035) and less long-term sickness leave (P = 0.040).

    Conclusions: This study provides evidence for the benefits of combining lumbar stabilization exercise and cognitive behavioural intervention starting immediately after lumbar fusion.

  • 116.
    Abbott, Allan
    et al.
    Karolinska University Hospital, Stockholm, Sweden.
    Tynni-Lenné, R
    Karolinska University Hospital, Stockholm, Sweden; Karolinska Institute, Stockholm, Sweden.
    Hedlund, R
    Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden.
    The effectiveness of physiotherapeutic rehabilitation and issues of outcome prediction after lumber fusion surgery.2011In: Proceedings of the WCPT Congress, Amsterdam Netherlands. / [ed] Physiotherapy, World Confederation of Physical Therapy , 2011, Vol. 97 (Suppl 1), 20- p.Conference paper (Other academic)
    Abstract [en]

    Purpose: The primary purpose was to analyse the short and long term effectiveness of physiotherapeutic rehabilitation programs performed during the first 3 month after lumbar fusion surgery. A secondary purpose was to analyse factors predicting long-term disability, back pain and health related quality of life (HRQOL) outcomes after lumbar fusion.

    Relevance: The study provides evidence for the effectiveness of early physiotherapy after lumbar fusion. Furthermore improved knowledge of predictive factors can help physiotherapist in the screening of lumbar fusion candidates and the individualised implementation of pre-surgical and post-surgical interventions.

    Participants: A total of 107 patients were recruited from the Karolinska University Hospital's Orthopaedic Clinic, Stockholm, Sweden. The inclusion criteria were: men and women aged between 18 and 65 years with a >12 month history of back pain and/or sciatica; a primary diagnosis of spinal stenosis, degenerative or isthmic spondylolisthesis or degenerative disc disease; selected for lumbar fusion with or without decompression; competence in the Swedish language. The criteria for exclusion were: previous lumbar fusion, rheumatoid arthritis and ankylosing spondylitis.

    Methods: An open book randomised controlled trial with pre-surgical and post-surgical measures at 3, 6, 12 and 24-36 months was performed to investigate the effectiveness of a psychomotor therapy focusing on cognition, behaviour and motor relearning compared to exercise therapy focusing on strength and conditioning, applied during the first 3 months after lumbar fusion. Randomisation allocated 53 patients to psychomotor therapy and 54 patients to exercise therapy. The Oswestry disability index (ODI) was the primary outcome measure. Secondary measures included the Visual analogue scale for back pain (VAS), European quality of life questionnaire (EQ5D), as well as other clinical, psychological and work related variables.

    Analysis: A total of 78 patients were needed assuming a power = 80%. Patient compliance was analysed and an intention to treat principle applied to data analysis. For statistical comparison between the 2 independent groups, analysis of covariance was used. Categorical regression with optimal scaling transformation, elastic net regularization and bootstrapping were used to investigate pre-surgical predictor variables and address predictive model validity.

    Results: Follow-up rates were 93% at 12 months and 81% at 24-36 months after surgery. Psychomotor therapy improved functional disability, self-efficacy, outcome expectancy and fear of movement/(re)injury significantly more than exercise therapy at respective follow-up occasions. Pre-surgical control over pain significantly predicted functional disability and HRQOL. Pre-surgical catastrophizing and leg pain intensity significantly predicted functional disability and back pain while the pre-surgical lasegue test significantly predicted back pain. The implementation of post-operative psychomotor therapy also significantly predicted functional disability while pre-surgical outcome expectations significantly predicted HRQOL.

    Conclusions: The study shows that post-operative rehabilitation can be safely implemented during the first 3 months after lumbar fusion and should include measures to modify psychological as well as motor functions. The study also demonstrates the importance of pre-surgical psychological factors, leg pain intensity, the lasegue test and post-operative psychomotor therapy in the predictions of functional disability, back pain and HRQOL related outcomes.

    Implications: Physiotherapist should screen patients pain, psychological factors and neuromusculoskeletal system pre-surgically and rehabilitate patients with early psychomotor therapy after lumbar fusion.

  • 117.
    Abbott, Allan
    et al.
    Karolinska Institute, Stockholm, Sweden.
    Tynni-Lenné, Raija
    Karolinska Institute, Stockholm, Sweden.
    Hedlund, Rune
    Gothenburg University, Gothenburg, Sweden.
    Early rehabilitation targeting cognition, behaviour and motor function after lumbar fusion: A randomised controlled trial2010In: Abstracts: Oral Presentations, 2010, 186-186 p.Conference paper (Other academic)
    Abstract [en]

    Study Design: Open label randomised controlled trial with 3, 6, 12 month and 2-3 year follow-up.

    Objective. To investigate the effectiveness of a psychomotor therapy focusing on cognition, behaviour and motor relearning compared to exercise therapy applied during the first 3 months after lumbar fusion.

    Methods: The study recruited 107 patients, aged 18 to 65 years, selected for lumbar fusion due to 12 months of symptomatic spinal stenosis, degenerative/isthmic spondylolisthesis or degenerative disc disease. The exercise therapy group received a home program focusing on pain contingent training of back, abdominal and leg muscle functional strength and endurance, stretching and cardiovascular fitness. The psychomotor therapy group received a home program and 3 outpatient sessions focusing on modifying maladaptive pain cognitions, behaviours and motor control. Patient-rated questionnaires investigating functional disability, pain, health related quality of life, functional self-efficacy, outcome expectancy, fear of movement/(re)injury and copingwere assessed at baseline, 3, 6, 12 months and 2-3 years after surgery.

    Results: Follow-up rates were 93% at 12 months and 81% at 2-3 years after surgery. Psychomotor therapy improved functional disability, self-efficacy, outcome expectancy and fear of movement/(re)injury significantly more than exercise therapy at respective follow-up occasions. Similar results occurred for pain coping but group differences were non-significant at 2-3 year follow-up.

    Conclusions: The study shows that post-operative rehabilitation can be effectively implemented during the first 3 months after lumbar fusion and should include measures to modify psychological aswell as motor functions.

  • 118.
    Abd Al Qahar Al-Kubaisy, Waqar
    et al.
    MARA University of Technology, Sungai Buloh, Malaysia; MARA University of Technology UiTM, Malaysia.
    Jawad Obaid, Kadhim
    MARA University of Technology, Sungai Buloh, Malaysia.
    Aini Mohd Noor, Nor
    MARA University of Technology, Sungai Buloh, Malaysia; MARA University of Technology UiTM, Shah Alam, Selangor, Malaysia.
    Shamsidah Binti Nik Ibrahim, Nik
    MARA University of Technology, Sungai Buloh, Malaysia.
    Albu-Kareem Al-Azawi, Ahmed
    Östergötlands Läns Landsting.
    Hepatitis C virus prevalence and genotyping among hepatocellular carcinoma patients in Baghdad2014In: Asian Pacific Journal of Cancer Prevention, ISSN 1513-7368, Vol. 15, no 18, 7725-7730 p.Article in journal (Refereed)
    Abstract [en]

    Hepatocellular carcinoma (HCC) is the third most common cause for cancer death in the world, now being especially linked to chronic hepatitis C virus (HCV) infection. This case-control study consisting of 65 HCC patients and 82 patients with other malignant tumours as controls was conducted to determine the association of HCV markers with HCC. Serum of each participant was obtained for detection of HCV Ab and RNA by DNA enzyme immunoassay (DEIA). Twenty six per cent (26.0%) of HCC patients had positive anti-HCV which was significantly greater than the control group (p=0.001). HCC patients significantly have a risk of exposure to HCV infection almost 3 times than the control group (OR=2.87, 95% C.I=1.1-7). Anti-HCV seropositive rate was significantly (p=0.03) higher among old age HCC patients and increases with age. Males with HCC significantly showed to have more than 9 times risk of exposure to HCV infection (OR=9.375, 95 % CI=1.299-67.647) than females. HCV-RNA seropositive rate was (70.8%) significantly higher among HCC patients compared to (22.2%) the control group (p=0.019). The most prevalent genotype (as a single or mixed pattern of infection) was HCV-1b. This study detected a significantly higher HCV seropositive rate of antibodies and RNA in HCC patients.

  • 119.
    Abdalla, Hana
    et al.
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Diab, Asim
    Department of Neurology, University of Texas Southwestern Medical Center, Dallas, USA.
    Forslund, Tony
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Bakhiet, Moiz
    Department of Medicine, Divisions of lnfectious Diseases, Karolinska Institute, Huddinge University Hospital, Stockholm, Sweden.
    Stendahl, Olle
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Molecular and Clinical Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Expression of inducible nitric oxide synthases and nitrotyrosine during the course of Haemophilus influenzae type b meningitis in ratManuscript (preprint) (Other academic)
    Abstract [en]

    Bacterial meningitis continues to be a major health problem and despite great advances in antimicrobial therapy the fatality rate remains high. There is increasing evidence that leukocyte-endothelial interactions are involved in CNS damage during bacterial meningitis. Once leukocytes have entered the CSF they cause injury by releasing toxic molecules such as nitric oxide (NO) and reactive oxygen species (ROS). The induction of iNOS was examined by assessing intracerebral mRNA expression and protein production during the course of Haemophilus influenzae type b (Hib) meningitis in the rat. Induction of iNOS mRNA was detected 12h postinoculation (pi), followed by a gradual reduction. The increased number of intracerebral iN OS expressing cells was detected at 12h pi. followed by further elevation to peak expression at 72h pi. The iNOS positive tissue also bound antibodies specific for nitrotyrosine. The expression of iNOS and NO production, as shown by nitrotyrosine expression, correlated with disease severity, suggesting that activation of iNOS may play an important role in Haemophilus irifluenzae type b meningitis.

  • 120.
    Abdalla, Hana
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Forslund, Tony
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Schön, Thomas
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Stendahl, Olle
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Sundqvist, Tommy
    Linköping University, Department of Clinical and Experimental Medicine, Medical Microbiology. Linköping University, Faculty of Health Sciences.
    Effects of CNI-1493 on human granulocyte functions2006In: Immunobiology, ISSN 0171-2985, E-ISSN 1878-3279, Vol. 211, no 3, 191-197 p.Article in journal (Refereed)
    Abstract [en]

    During acute bacterial infections such as sepsis and meningitis, activation of inflammatory mediators such as nitric oxide (NO) plays a crucial role in both pathogenesis and host defense. We have previously reported that CNI-1493, a macrophage deactivator, reduced mortality in infant rats infected with Haemophilus influenzae type b (Hib) with associated decrease in the number of granulocytes in the infected tissue. The aim of the present study was to investigate how CNI-1493 affects granulocytes and macrophages in vitro. Murine macrophages (RAW 264.7) pre-incubated with CNI-1493 prior to activation with lipopolysaccharide (LPS)/interferon gamma (IFNγ) had decreased NO production measured as NO2/NO3 levels and reduction in inducible NO-synthase (iNOS) expression. Reactive oxygen species (ROS) production was increased in formylmethionyl-leucyl-phenylalanine (FMLP)-stimulated granulocytes following CNI-1493 treatment, whereas F-actin content, motility and chemotaxis were decreased under the same conditions. The effects of CNI-1493 on both NO production in LPS/IFNγ-activated macrophages and ROS production, F-actin content, motility and chemotaxis in granulocytes, may contribute to the reduced inflammatory response and increased survival in Hib-infected animals treated with CNI-1493.

  • 121.
    Abdalla, Hassan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Fabiano, Simone
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    Investigation of the dimensionality of charge transport in organic field effect transistors2017In: Physical Review B, ISSN 2469-9950, E-ISSN 2469-9969, Vol. 95, no 8, 85301Article in journal (Refereed)
    Abstract [en]

    Ever since the first experimental investigations of organic field effect transistors (OFETs) the dimensionality of charge transport has alternately been described as two dimensional (2D) and three dimensional (3D). More recently, researchers have turned to an analytical analysis of the temperature-dependent transfer characteristics to classify the dimensionality as either 2D or 3D as well as to determine the disorder of the system, thereby greatly simplifying dimensionality investigations. We applied said analytical analysis to the experimental results of our OFETs comprising molecularly well-defined polymeric layers as the active material as well as to results obtained from kinetic Monte Carlo simulations and found that it was not able to correctly distinguish between 2D and 3D transports or give meaningful values for the disorder and should only be used for quasiquantitative and comparative analysis. We conclude to show that the dimensionality of charge transport in OFETs is a function of the interplay between transistor physics and morphology of the organic material.

  • 122.
    Abdalla, Hassan
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering.
    van de Ruit, Kevin
    Eindhoven University of Technology, Netherlands.
    Kemerink, Martijn
    Linköping University, Department of Physics, Chemistry and Biology, Complex Materials and Devices. Linköping University, Faculty of Science & Engineering. Eindhoven University of Technology, Netherlands.
    Effective Temperature and Universal Conductivity Scaling in Organic Semiconductors2015In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 5, 16870Article in journal (Refereed)
    Abstract [en]

    We investigate the scalability of the temperature-and electric field-dependence of the conductivity of disordered organic semiconductors to universal curves by two different but commonly employed methods; by so-called universal scaling and by using the effective temperature concept. Experimentally both scaling methods were found to be equally applicable to the out-of-plane charge transport in PEDOT: PSS thin films of various compositions. Both methods are shown to be equivalent in terms of functional dependence and to have identical limiting behavior. The experimentally observed scaling behavior can be reproduced by a numerical nearest-neighbor hopping model, accounting for the Coulomb interaction, the high charge carrier concentration and the energetic disorder. The underlying physics can be captured in a simple empirical model, describing the effective temperature of the charge carrier distribution as the outcome of a heat balance between Joule heating and (effective) temperature-dependent energy loss to the lattice.

  • 123.
    Abdalla, Maie
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Suez Canal University, Egypt.
    Landerholm, Kalle
    Ryhov County Hospital, Sweden.
    Andersson, Peter
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Andersson, Roland
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Ryhov County Hospital, Sweden.
    Myrelid, Pär
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Center for Surgery, Orthopaedics and Cancer Treatment, Department of Surgery in Linköping.
    Risk of Rectal Cancer After Colectomy for Patients With Ulcerative Colitis: A National Cohort Study2017In: Clinical Gastroenterology and Hepatology, ISSN 1542-3565, E-ISSN 1542-7714, Vol. 15, no 7, 1055-1060 p., e2Article in journal (Refereed)
    Abstract [en]

    BACKGROUND amp; AIMS: Patients with ulcerative colitis (UC) have an increased risk of rectal cancer, therefore reconstruction with an ileal pouch-anal anastomosis (IPAA) generally is preferred to an ileorectal anastomosis (IRA) after subtotal colectomy. Similarly, completion proctectomy is recommended for patients with ileostomy and a diverted rectum, although this approach has been questioned because anti-inflammatory agents might reduce cancer risk. We performed a national cohort study in Sweden to assess the risk of rectal cancer in patients with UC who have an IRA, IPAA, or diverted rectum after subtotal colectomy.

    METHODS: We collected data from the Swedish National Patient Register for a cohort of 5886 patients with UC who underwent subtotal colectomy with an IRA, IPAA, or diverted rectum from 1964 through 2010. Patients who developed rectal cancer were identified from the Swedish National Cancer Register. The risk of rectal cancer was compared between this cohort and the general population by standardized incidence ratio analysis.

    RESULTS: Rectal cancer occurred in 20 of 1112 patients (1.8%) who received IRA, 1 of 1796 patients (0.06%) who received an IPAA, and 25 of 4358 patients (0.6%) with a diverted rectum. Standardized incidence ratios for rectal cancer were 8.7 in patients with an IRA, 0.4 in patients with an IPAA, and 3.8 in patients with a diverted rectum. Risk factors for rectal cancer were primary sclerosing cholangitis in patients with an IRA (hazard ratio, 6.12), and colonic severe dysplasia or cancer before subtotal colectomy in patients with a diverted rectum (hazard ratio, 3.67).

    CONCLUSIONS: In an analysis of the Swedish National Patient Register, we found that the risk for rectal cancer after colectomy in patients with UC is low, in relative and absolute terms, after reconstruction with an IPAA. An IRA and diverted rectum are associated with an increased risk of rectal cancer, compared with the general population, but the absolute risk is low. Patients and their health care providers should consider these findings in making decisions to leave the rectum intact, perform completion proctectomy, or reconstruct the colon with an IRA or IPAA.

  • 124.
    Abdelrahman, Islam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Elmasry, Moustafa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Olofsson, Pia
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Steinvall, Ingrid
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Fredrikson, Mats
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Sjöberg, Folke
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Division of overall duration of stay into operative stay and postoperative stay improves the overall estimate as a measure of quality of outcome in burn care.2017In: PLoS ONE, ISSN 1932-6203, E-ISSN 1932-6203, Vol. 12, no 3, e0174579Article in journal (Refereed)
    Abstract [en]

    Patients and Methods: Surgically managed burn patients admitted between 2010-14 were included. Operative stay was defined as the time from admission until the last operation, postoperative stay as the time from the last operation until discharge. The difference in variation was analysed with F-test. A retrospective review of medical records was done to explore reasons for extended postoperative stay. Multivariable regression was used to assess factors associated with operative stay and postoperative stay.less thanbr /greater thanResults: Operative stay/TBSA% showed less variation than total duration/TBSA% (F test = 2.38, pless than0.01). The size of the burn, and the number of operations, were the independent factors that influenced operative stay (R2 0.65). Except for the size of the burn other factors were associated with duration of postoperative stay: wound related, psychological and other medical causes, advanced medical support, and accommodation arrangements before discharge, of which the two last were the most important with an increase of (mean) 12 and 17 days (pless than0.001, R2 0.51).less thanbr /greater thanConclusion: Adjusted operative stay showed less variation than total hospital stay and thus can be considered a more accurate outcome measure for surgically managed burns. The size of burn and number of operations are the factors affecting this outcome measure.

  • 125.
    Abdelrahman, Islam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Elmasry, Moustafa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. a Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Steinvall, Ingrid
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Fredrikson, Mats
    Linköping University, Department of Clinical and Experimental Medicine, Division of Neuro and Inflammation Science. Linköping University, Faculty of Medicine and Health Sciences.
    Sjöberg, Folke
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Improvement in mortality at a National Burn Centre since 2000: Was it the result of increased resources?2017In: Medicine (Baltimore, Md.), ISSN 0025-7974, E-ISSN 1536-5964, Vol. 96, no 25, e6727Article in journal (Refereed)
    Abstract [en]

    Abstract The aim of this study was to find out whether the charging costs (calculated using interventional burn score) increased as mortality decreased. During the last 2 decades, mortality has declined significantly in the Linköping Burn Centre. The burn score that we use has been validated as a measure of workload and is used to calculate the charging costs of each burned patient. We compared the charging costs and mortality in 2 time periods (2000–2007 and 2008–2015). A total of 1363 admissions were included. We investigated the change in the burn score, as a surrogate for total costs per patient. Multivariable regression was used to analyze risk-adjusted mortality and burn score. The median total body surface area % (TBSA%) was 6.5% (10–90 centile 1.0–31.0), age 33 years (1.3–72.2), duration of stay/ TBSA% was 1.4 days (0.3–5.3), and 960 (70%) were males. Crude mortality declined from 7.5% in 2000–2007 to 3.4% in 2008–2015, whereas the cumulative burn score was not increased (P=.08). Regression analysis showed that risk-adjusted mortality decreased (odds ratio 0.42, P=.02), whereas the adjusted burn score did not change (P=.14, model R2 0.86). Mortality decreased but there was no increase in the daily use of resources as measured by the interventional burn score. The data suggest that the improvements in quality obtained have been achieved within present routines for care of patients (multidisciplinary/ orientated to patients’ safety).

    Abbreviation: TBSA% = total body surface area %.

  • 126.
    Abdelrahman, Islam
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Suez Canal University, Egypt.
    Moghazy, Amr
    Suez Canal University, Egypt.
    Abbas, Ashraf
    Suez Canal University, Egypt.
    Elmasry, Moustafa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Suez Canal University, Egypt.
    Adly, Osama
    Suez Canal University, Egypt.
    Elbadawy, Mohamed
    Suez Canal University, Egypt.
    Steinvall, Ingrid
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Sjöberg, Folke
    Linköping University, Department of Clinical and Experimental Medicine, Division of Clinical Sciences. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    A prospective randomized cost billing comparison of local fasciocutaneous perforator versus free Gracilis flap reconstruction for lower limb in a developing economy2016In: Journal of Plastic, Reconstructive & Aesthetic Surgery, ISSN 1748-6815, E-ISSN 1532-1959, Vol. 69, no 8, 1121-1127 p.Article in journal (Refereed)
    Abstract [en]

    Distal half leg complex wounds are usually a formidable problem that necessitates either local or free flap coverage. The aim of this study was to compare cost billing charges in free Gracilis flap (fGF) and local fasciocutaneous perforator flap (lFPF) in reconstructing complex soft tissue leg and foot defects. Patients and methods: Thirty consecutive adult (amp;gt; 15-year-old) patients with soft tissue defects in the leg and/or foot requiring tissue coverage with a flap in the period between 2012 and 2015 were randomly assigned (block randomization) to either an fGF or lFPF procedure. The outcome measures addressed were total billed charges costs, perioperative billed charges cost, partial or complete flap loss, length of hospital stay, inpatient postsurgical care duration, complications, operating time and number of operative scrub staff. Results: One patient suffered from complete flap loss in each group. Reconstruction with lFPF showed total lower billed charges costs by 62% (2509 USD) (p amp;lt; 0.001) and perioperative billed charges cost by 54% (779 USD) (p amp;lt; 0.001), and shorter total hospital stay (36.5 days; p amp;lt; 0.001), inpatient postsurgical care duration (6.4 days; p amp;lt; 0.001), operating time (4.3 h; p amp;lt; 0.001) and fewer scrub staff (2.2 persons; p amp;lt; 0.001). Conclusion: These results suggest that neither flap is totally superior to the other; the choice should instead be based on the outcome sought and logistics. lFPF requires lower billed charges cost and resource use and saves operative time and personnel and reduces length of hospital stay. Our approach changed towards using perforator flaps in medium-sized defects, keeping the free flap option for larger defects. (C) 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  • 127.
    Abdelrahman, Islam Mohamedy
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Elmasry, Moustafa
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Plastic Surgery Unit, Surgery Department, Suez Canal University, Ismailia, Egypt.
    Steinvall, Ingrid
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery.
    Sjöberg, Folke
    Linköping University, Department of Clinical and Experimental Medicine, Division of Surgery, Orthopedics and Oncology. Linköping University, Faculty of Medicine and Health Sciences. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Hand and Plastic Surgery. Region Östergötland, Anaesthetics, Operations and Specialty Surgery Center, Department of Anaesthesiology and Intensive Care in Linköping.
    Response to comments on: A prospective randomized cost billing comparison of local fasciocutaneous perforator versus free Gracilis flap reconstruction for lower limb in a developing economy2017In: Journal of Plastic, Reconstructive & Aesthetic Surgery, ISSN 1748-6815, E-ISSN 1532-1959, Vol. 70, no 9, 1307-1308 p.Article in journal (Other academic)
  • 128.
    Abdgawad, M.
    et al.
    Departments of Nephrology, Lund University, Lund, Sweden.
    Gunnarsson, L.
    Departments of Nephrology, Lund University, Lund, Sweden.
    Bengtsson, A. A.
    Departments of Rheumatology, Lund University, Lund, Sweden.
    Geborek, P.
    Departments of Rheumatology, Lund University, Lund, Sweden.
    Nilsson, L.
    Departments of Haematology, Lund University, Lund, Sweden.
    Segelmark, Mårten
    Departments of Nephrology, Lund University, Lund, Sweden.
    Hellmark, T.
    Departments of Nephrology, Lund University, Lund, Sweden.
    Elevated neutrophil membrane expression of proteinase 3 is dependent upon CD177 expression2010In: Clinical and Experimental Immunology, ISSN 0009-9104, E-ISSN 1365-2249, Vol. 161, no 1, 89-97 p.Article in journal (Refereed)
    Abstract [en]

    Proteinase 3 (PR3) is a major autoantigen in anti-neutrophil cytoplasmic antibodies (ANCA)-associated systemic vasculitis (AASV), and the proportion of neutrophils expressing PR3 on their membrane (mPR3+) is increased in AASV. We have shown recently that mPR3 and CD177 are expressed on the same cells in healthy individuals. In this study we try to elucidate mechanisms behind the increased mPR3 expression in AASV and its relationship to CD177. All neutrophils in all individuals were either double-positive or double-negative for mPR3 and CD177. The proportion of double-positive neutrophils was increased significantly in AASV and systemic lupus erythematosus patients. The proportion of mPR3+/CD177+ cells was not correlated to general inflammation, renal function, age, sex, drug treatment and levels of circulating PR3. AASV patients had normal levels of granulocyte colony-stimulating factor and granulocyte–macrophage colony-stimulating factor. Pro-PR3 was found to constitute 10% of circulating PR3 but none of the mPR3. We found increased mRNA levels of both PR3 and CD177 in AASV, but they did not correlate with the proportion of double-positive cells. In cells sorted based on membrane expression, CD177–mRNA was several-fold higher in mPR3+ cells. When exogenous PR3 was added to CD177-transfected U937 cells, only CD177+ cells bound PR3 to their membrane. In conclusion, the increased membrane expression of PR3 found in AASV is not linked directly to circulating PR3 or PR3 gene transcription, but is dependent upon CD177 expression and correlated with the transcription of the CD177 gene.

  • 129.
    Abdgawad, Mohamed
    et al.
    Lund University.
    Pettersson, Asa
    Lund University.
    Gunnarsson, Lena
    Lund University.
    Bengtsson, Anders A
    Lund University.
    Geborek, Pierre
    Lund University.
    Nilsson, Lars
    Lund University.
    Segelmark, Mårten
    Linköping University, Department of Medical and Health Sciences, Pharmacology. Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Heart and Medicine Centre, Department of Nephrology UHL.
    Hellmark, Thomas
    Lund University.
    Decreased Neutrophil Apoptosis in Quiescent ANCA-Associated Systemic Vasculitis2012In: PLoS ONE, ISSN 1932-6203, Vol. 7, no 3Article in journal (Refereed)
    Abstract [en]

    Background: ANCA-Associated Systemic Vasculitis (AASV) is characterized by leukocytoclasis, accumulation of unscavenged apoptotic and necrotic neutrophils in perivascular tissues. Dysregulation of neutrophil cell death may contribute directly to the pathogenesis of AASV. less thanbrgreater than less thanbrgreater thanMethods: Neutrophils from Healthy Blood Donors (HBD), patients with AASV most in complete remission, Polycythemia Vera (PV), Systemic Lupus Erythematosus (SLE), Rheumatoid Arthritis (RA) and renal transplant recipients (TP) were incubated in vitro, and the rate of spontaneous apoptosis was measured by FACS. Plasma levels of cytokines and sFAS were measured with cytometric bead array and ELISA. Expression of pro/anti-apoptotic factors, transcription factors C/EBP-alpha, C/EBP-beta and PU.1 and inhibitors of survival/JAK2-pathway were measured by real-time-PCR. less thanbrgreater than less thanbrgreater thanResults: AASV, PV and RA neutrophils had a significantly lower rate of apoptosis compared to HBD neutrophils (AASV 50 +/- 14% vs. HBD 64 +/- 11%, p andlt; 0.0001). In RA but not in AASV and PV, low apoptosis rate correlated with increased plasma levels of GM-CSF and high mRNA levels of anti-apoptotic factors Bcl-2A1 and Mcl-1. AASV patients had normal levels of G-CSF, GM-CSF and IL-3. Both C/EBP-alpha, C/EBP-beta were significantly higher in neutrophils from AASV patients than HBD. Levels of sFAS were significantly higher in AASV compared to HBD. less thanbrgreater than less thanbrgreater thanConclusion: Neutrophil apoptosis rates in vitro are decreased in AASV, RA and PV but mechanisms seem to differ. Increased mRNA levels of granulopoiesis-associated transcription factors and increased levels of sFAS in plasma were observed in AASV. Additional studies are required to define the mechanisms behind the decreased apoptosis rates, and possible connections with accumulation of dying neutrophils in regions of vascular lesions in AASV patients.

  • 130.
    Abdiu, Avni
    Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Linköping University, Faculty of Health Sciences.
    Growth regulation in sarcomas: studies in vivo and in cell culture1999Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Sarcomas are malignant tumors of mesenchymal origin, and can arise in soft-tissue and in bones. It has been suggested that the abnormal growth regulation in sarcoma cells may be due to an autocrine mechanism, in which the cells are stimulated by an endogenous production of growth factors. Platelet-derived growth factor (PDGF) has been detected in sarcomas, and may be one of the growth factors important for sarcoma growth.

    PDGF, originally discovered in platelets, is produced by, and binds to, a variety of cells. PDGF plays several roles both in normal conditions and in disease.

    Suramin is a polyanionic drug with antineoplastic activities, and is known to dissociate growth factors from their receptors. Suramin has been shown to inhibit growth in several tumors and tumor cell lines; however, some tumor cells have been unaffected, or even stimulated, by suramin.

    The present work was performed in order to a) examine the effects of suramin on sarcoma growth in vivo; b) investigate the kinetics of extravascularly administered PDGF in vivo; c) establish and characterize human sarcoma cells in vitro, including their relation to PDGF; d) evaluate the effects of suramin on sarcoma growth in vitro; e) compare the effects of PDGF on sarcoma growth in vivo and in vitro.

    Suramin was shown to inhibit growth of two different human osteosarcoma xenografts grown in nude mice. The action is believed to be mainly cytostatic, as the tumors continued to grow, albeit at a lower pace: the tumors of the suramin treated mice had a volume of one-third or less than the untreated ones. The percentage of cells in S and G2-M cell cycle phases was increased by suramin treatment, suggesting a selective effect of the drug in the S and G2 period.

    Blood and serum levels of 125I, after extravascular administration of 125I-PDGF-AB by intraperitoneal, intramuscular or subcutaneous injection in mice, were found to rise to a maximum 2-4 hours after injection. The levels of radioactivity persisted over several hours. Precipitiation of serum with 10% trichloracetic acid revealed that more than 50% of the radioactivity was in a macromolecular form. Gel chromatography of the serum showed that a major portion of the radioactive material in the circulation had the same molecular size as the original 125I-PDGF-AB.

    Eight cell lines derived from malignant fibrous histiocytomas (MFH) were established and characterized. A heterogeneity in the morphology of the MFH cell lines was noted. This heterogeneity was also reflected in the expression of mRNA for PDGF, transforming growth factor-alpha (TGF-/alpha/) and their receptors, ability to grow in serumfree media and secretion of PDGF into growth media. Two cell lines, able to grow in serum-free medium, coexpressed MRNA for PDGF, TGF-/aplpha/ and their receptors, suggesting that they may be regulated in an autocrine manner. However, other cell lines, unable to grow in a serum-free medium, also displayed this coexpression of mRNA. The simultaneous expression of a growth factor and its receptor is therefore not generally indicative of an autocrine mechanism.

    All cell lines, unable to grow in a serum-free medium, were growth inhibited by high-dose suramin (200 ug/ml). The two cell lines, previously noted to grow under serum-free conditions, were not affected by the high-dose suramin treatment. The finding that only serum-dependent human MFH cell lines were inhibited by high doses of suramin indicates that serum dependence in vitro may predict sensitivity of sarcoma cells to suramin.

    Two human sarcoma xenografts, one osteosarcoma and one malignant fibrous histiocytoma, were treated with human PDGF-AB when grown in nude mice. No effects on tumor growth were noted, although immunohistochemical studies revealed an expression of PDGF receptors. Furthermore, both sarcomas were markedly stimulated by PDGF-AB in vitro. It is concluded that mechanisms or factors other than available PDGF were limiting the growth of the examined tumors in vivo.

  • 131.
    Abdiu, Avni
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Larsson, Sven-Erik
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Orthopaedics and Sports Medicine. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Wasteson, Åke
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Cell biology.
    Walz, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Suramin blocks growth-stimulatory effects of platelet-derived growth factor on malignant fibrous histiocytomas in vitro.1999In: Cancer Letters, ISSN 0304-3835, Vol. 146, 189-194 p.Article in journal (Refereed)
  • 132.
    Abdiu, Avni
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Nakamura, Hajime
    Sahaf, Bita
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Cell biology.
    Yodoi, Junji
    Holmgren, Arne
    Rosén, Anders
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Cell biology.
    Thioredoxin blood level increases after severe burn injury2000In: Antioxidants and Redox Signaling, ISSN 1523-0864, Vol. 2, no 4, 707-716 p.Article in journal (Refereed)
    Abstract [en]

    We have investigated the thioredoxin (TRX) levels in severely burned patients and the possible origin of TRX, based on the recent understanding that TRX is a potent antioxidant with cytoprotective functions. Serum and plasma samples from burns patients and healthy blood donors were collected during the first 10 post-bum days and analyzed in a sandwich TRX enzyme-linked immunosorbent assay (ELISA). The TRX levels found were correlated to a panel of blood tests. The presence of TRX in platelets was investigated by immunoelectron microscopy and Western blotting. TRX serum levels of the severely burned patients showed a significant increase, with a mean serum TRX concentration on the day of injury of 76.5 ▒ 19.5 ng/ml (mean ▒ SD) and on post-burn day one 122.6 ▒ 66.9 ng/ml, compared to control blood donor levels of 22.7 ▒ 12.2 ng/ml (p = 0.0041 and 0.0117, respectively). A second peak of increase was found on post-burn days 7 to 9 with a four- to five-fold rise in concentration compared to controls. TRX elevation correlated well with increased platelet (p = 0.007) and leukocyte counts (p = 0.002). We also demonstrated by immunoelectron microscopy and Western blotting the presence of TRX in platelets. In conclusion, our demonstration of TRX release in burn injuries indicates that the TRX system is involved in a rapid antioxidant defense, coagulation processes, cell growth, and control of the extracellular peroxide tone intimately linked to cytoprotection and wound healing in burns. One of the cell types that delivers TRX promptly and efficiently into the blood may be the platelet.

  • 133.
    Abdiu, Avni
    et al.
    Linköping University, Department of Clinical and Experimental Medicine, Surgery . Linköping University, Faculty of Health Sciences. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Ohannessian, Peter
    Östergötlands Läns Landsting, Reconstruction Centre, Department of Oral Surgery UHL.
    Berggren, Anders
    Linköping University, Department of Clinical and Experimental Medicine, Surgery . Linköping University, Faculty of Health Sciences.
    The nasal alar elevator: A new device that may reduce the need for primary operation of the nose in patients with cleft lip2009In: SCANDINAVIAN JOURNAL OF PLASTIC AND RECONSTRUCTIVE SURGERY AND HAND SURGERY, ISSN 0284-4311, Vol. 43, no 2, 71-74 p.Article in journal (Refereed)
    Abstract [en]

    To improve the shape of the cleft lip nose preoperatively, we have developed the nasal alar elevator. This has been used routinely since 1996 on all our cleft lip patients who have an asymmetrical nose, from the first week after birth until the date of primary lip surgery. We present our 11-year-long experience of using the device on patients born with complete, unilateral cleft lip. In this study 56 children, born between 1996 and 2006 inclusive, with complete unilateral cleft lip, had preoperative treatment with the elevator. During this 11-year period, continuous evaluation during the preoperative period, and its effects on the cleft lip nose, were evaluated, both preoperatively and postoperatively. Our results show that the preoperative use of the device has led to less need for primary nasal surgery. Instead of having to have a primary rhinoplasty (McComb) together with a lip plasty, as a routine, now only about 30% of the patients need primary surgical correction of the nose. If nasal correction is needed, a rather limited undermining of skin over the ala on the cleft side will often be sufficient. The use of a nasal elevator reduces both the length and the extent of the primary intervention, without compromising the final result.

  • 134.
    Abdiu, Avni
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Plastic Surgery, Hand Surgery and Burns. Östergötlands Läns Landsting, Reconstruction Centre, Department of Plastic Surgery, Hand surgery UHL.
    Wingren, Sten
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology.
    Larsson, S-E
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Neuroscience and Locomotion, Orthopaedics and Sports Medicine. Östergötlands Läns Landsting, Orthopaedic Centre, Department of Orthopaedics Linköping.
    Wasteson, Åke
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Cell biology.
    Walz, Thomas
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Biomedicine and Surgery, Oncology. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Oncology UHL.
    Effects of human platelet-derived growth factor-AB on sarcoma growth in vitro and in vivo.1999In: Cancer Letters, ISSN 0304-3835, Vol. 141, 39-45 p.Article in journal (Refereed)
  • 135.
    Abdollahi Sani, Negar
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Robertsson, Mats
    Linköping University, Department of Science and Technology. Linköping University, The Institute of Technology.
    Cooper, Philip
    De La Rue Plc, Overton, Hampshire, UK .
    Wang, Xin
    Acreo AB, Norrköping, Sweden.
    Svensson, Magnus
    Acreo AB, Norrköping, Sweden.
    Andersson Ersman, Peter
    Acreo AB, Norrköping, Sweden.
    Norberg, Petronella
    Acreo AB, Norrköping, Sweden.
    Nilsson, Marie
    Acreo AB, Norrköping, Sweden.
    Nilsson, David
    Acreo AB, Norrköping, Sweden.
    Liu, Xianjie
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Hesselbom, Hjalmar
    Hesselbom Innovation and Development HB, Huddinge, Sweden .
    Akesso, Laurent
    De La Rue Plc, Overton, Hampshire, UK .
    Fahlman, Mats
    Linköping University, Department of Physics, Chemistry and Biology, Surface Physics and Chemistry. Linköping University, The Institute of Technology.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Engquist, Isak
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, The Institute of Technology. Acreo AB, Norrköping, Sweden.
    Gustafsson, Goran
    Acreo AB, Norrköping, Sweden.
    All-printed diode operating at 1.6 GHz2014In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 111, no 33, 11943-11948 p.Article in journal (Refereed)
    Abstract [en]

    Printed electronics are considered for wireless electronic tags and sensors within the future Internet-of-things (IoT) concept. As a consequence of the low charge carrier mobility of present printable organic and inorganic semiconductors, the operational frequency of printed rectifiers is not high enough to enable direct communication and powering between mobile phones and printed e-tags. Here, we report an all-printed diode operating up to 1.6 GHz. The device, based on two stacked layers of Si and NbSi2 particles, is manufactured on a flexible substrate at low temperature and in ambient atmosphere. The high charge carrier mobility of the Si microparticles allows device operation to occur in the charge injection-limited regime. The asymmetry of the oxide layers in the resulting device stack leads to rectification of tunneling current. Printed diodes were combined with antennas and electrochromic displays to form an all-printed e-tag. The harvested signal from a Global System for Mobile Communications mobile phone was used to update the display. Our findings demonstrate a new communication pathway for printed electronics within IoT applications.

  • 136.
    Abdollahi Sani, Negar
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Wang, Xin
    Acreo Swedish ICT AB, Sweden.
    Granberg, Hjalmar
    INNVENTIA AB, Sweden.
    Andersson Ersman, Peter
    Acreo Swedish ICT AB, Sweden.
    Crispin, Xavier
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Dyreklev, Peter
    Acreo Swedish ICT AB, Sweden.
    Engquist, Isak
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gustafsson, Göran
    Acreo Swedish ICT AB, Sweden.
    Berggren, Magnus
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Flexible Lamination-Fabricated Ultra-High Frequency Diodes Based on Self-Supporting Semiconducting Composite Film of Silicon Micro-Particles and Nano-Fibrillated Cellulose2016In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 6, no 28921Article in journal (Refereed)
    Abstract [en]

    Low cost and flexible devices such as wearable electronics, e-labels and distributed sensors will make the future "internet of things" viable. To power and communicate with such systems, high frequency rectifiers are crucial components. We present a simple method to manufacture flexible diodes, operating at GHz frequencies, based on self-adhesive composite films of silicon micro-particles (Si-mu Ps) and glycerol dispersed in nanofibrillated cellulose (NFC). NFC, Si-mu Ps and glycerol are mixed in a water suspension, forming a self-supporting nanocellulose-silicon composite film after drying. This film is cut and laminated between a flexible pre-patterned Al bottom electrode and a conductive Ni-coated carbon tape top contact. A Schottky junction is established between the Al electrode and the Si-mu Ps. The resulting flexible diodes show current levels on the order of mA for an area of 2 mm(2), a current rectification ratio up to 4 x 10(3) between 1 and 2 V bias and a cut-off frequency of 1.8 GHz. Energy harvesting experiments have been demonstrated using resistors as the load at 900 MHz and 1.8 GHz. The diode stack can be delaminated away from the Al electrode and then later on be transferred and reconfigured to another substrate. This provides us with reconfigurable GHz-operating diode circuits.

  • 137.
    Abdolmajid Ahmad, Bookan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Programmering av generativ konst i C# .Net2014Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [sv]

    Detta examensarbete utfördes på IDA (Institutionen för datavetenskap) vid Linköpings universitet. 

    Syftet med det här examensarbetet var att utveckla ett program som skulle skapa förutsättningar för generativ konst med hjälp av MyPaint som är ett digitalt rit/målarverktyg. Metoden gick ut på att registrera vad användaren skapat för komponenter, dvs. musinteraktioner och kortkommandon, och därefter använda dem algoritmiskt.

    Examensarbetet resulterades i ett program (SharpArt), som fångar musinteraktioner samt simulerar tangentbordstryckningar (kortkommandon) från och till Mypaint, vilket i sin tur skapar komponenter som används algoritmiskt. Programmet kan även positionera objektet på canvasen enligt det önskade koordinatvärdet.

  • 138.
    Abdul Aziz Hasan Ali, Aamir
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Shahzad, Muhammad Adil
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A Joint Subcarrier/Power allocation Scheme for OFDMA-based Cellular Networks2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The assignment of this master thesis consists of initiating power, subcarrier allocation in a dynamic FFR based scheme designed for multi-cell OFDMA networks and to enhance the throughput of all center users in bandwidth hungry borrower cells (overloaded cells) which was previously degraded by original FFR3 scheme as a result of partitioning of system bandwidth into center and edge bands respectively. The method uses band borrowing to compensate center user’s throughput loss in a semi and fully overloaded system. The scheme uses dynamic programming method (0/1 knapsack problem) to bargain an edge band on various power levels and tends to check the best combination (power and sub-carrier) which the system can utilize while still maintaining acceptable throughput loss for the users at the edge of the neighboring cell (lender cell).

    The algorithm consists of generating a borrowing request to neighboring cells for utilizing their edge bands by the overloaded borrower cell if their average center user throughput reaches below a minimum threshold value set in the system. The borrowing method uses 0/1 knapsack problem to capture an edge band based on limiting factors of total cost in average throughput losses by neighbors (Ci) and Un (tolerable mean user edge user throughput loss by lending cell). While solving knapsack problem the lender (neighbors) will check Ci and Un before granting the right to use its edge band. The later stage requires reducing subcarrier power level in order to utilize the lenders edge band using "soft borrower" mode. The borrowed sub-carriers will be activated take power from the original center band sub-carriers of the overloaded cell by taking into account the interference between the lender and the borrower. In case of negative (0) reply from the lender cell after the first request, multiple requests are generated at reduce power level at every step to order to acquire more bands. If a neighbor has band borrowing requests from multiple overloaded base stations, the band will be granted to the one which gives minimal loss in terms of throughput to the lender cell.

    The simulation results are analyzed w.r.t reuse-1 and FFR3 scheme of a multi cell regular and irregular scenarios comprising of lightly to heavily overloaded cells with various subcarrier allocation patterns. An overhead and time assessment is also presented between borrower and lender cells. Simulation results show an increase of 60% in center user’s throughput w.r.t original FFR3 scheme with an acceptable loss of 18% at the edges in complex overloaded scenarios while the overall system throughout increases by 35%.

  • 139.
    Abdul Malek, Nurul Aida
    et al.
    Universiti Tun Hussein Onn Malaysia (UTHM), Malaysia / Department of Production, University of Vaasa, Finland.
    Shahzad, Khuram
    Department of Production, University of Vaasa, Finland.
    Takala, Josu
    Department of Production, University of Vaasa, Finland.
    Bojnec, Stefan
    Faculty of Management, University of Primorska, Slovenia.
    Papler, Drago
    Faculty of Management, University of Primorska, Slovenia.
    Liu, Yang
    Department of Production, University of Vaasa, Finland.
    Analyzing Sustainable Competitive Advantage: Strategically Managing Resource Allocations to Achieve Operational Competitiveness2015In: Management and Production Engineering Review, ISSN 2080-8208, E-ISSN 2082-1344, Vol. 6, no 4, 70-86 p.Article in journal (Refereed)
    Abstract [en]

    In today’s dynamic business environment, a key challenge for all companies is to make adaptive adjustments to their manufacturing strategy. This study demonstrates the competitive priorities of manufacturing strategy in hydro-power case company to evaluate the level of sustainable competitive advantage and also to further analyze how business strategies are aligned with manufacturing strategies. This research is based on new holistic analytical evaluation of manufacturing strategy index, sense and respond, and sustainable competitive advantage models. These models help to describe, evaluate, and optimize resource allocation to meet the performance requirements in dynamic decision making. Furthermore, these models evaluate operational competitiveness for manufacturing strategies according to the multi-criteria priority. The results show that the adjustments of competitive priorities in manufacturing strategies by implementing the proposed holistic analytical models are helpful in strategically managing business operations. The discussion derives the most critical attributes in business operations while alignment of resource allocation with competitive priorities help to strategically focus those attributes. In conclusion, we argue that resource allocation and manufacturing strategies have become the most important capabilities in a business environment where companies focus to get a sustainable competitive advantage.

  • 140.
    Abdulahad, Bassam
    et al.
    Linköping University, Department of Computer and Information Science.
    Lounis, Georgios
    Linköping University, Department of Computer and Information Science.
    A user interface for the ontology merging tool SAMBO2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    Ontologies have become an important tool for representing data in a structured manner. Merging ontologies allows for the creation of ontologies that later can be composed into larger ontologies as well as for recognizing patterns and similarities between ontologies. Ontologies are being used nowadays in many areas, including bioinformatics. In this thesis, we present a desktop version of SAMBO, a system for merging ontologies that are represented in the languages OWL and DAML+OIL. The system has been developed in the programming language JAVA with JDK (Java Development Kit) 1.4.2. The user can open a file locally or from the network and can merge ontologies using suggestions generated by the SAMBO algorithm. SAMBO provides a user-friendly graphical interface, which guides the user through the merging process.

  • 141.
    Abdulhamidova, Nurangez
    Linköping University, Department of Management and Engineering.
    The European Union-Central Asia: in the light of the New Strategy2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Central Asia is a region strategically located on the crossroads of the two continents. The region is represented by five states (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) with different level of economic development and with the population amounting to over 60 million people. The region is rich in energy resources, represented by oil, gas, coal and hydropower resources.

    The thesis analyses, assesses and scrutinises one of the topical issues of the contemporary international relations - cooperation between the European Union and Central Asian states before and after adoption in June 2007 of the ‘European Union and Central Asia: Strategy for a New Partnership’, an important political document in the history of relations between the two parties.

    The new stage of cooperation is analysed more comprehensively accentuating priorities set in the Strategy. Analysis of the current state of affairs is conducted concerning some important issues of the Strategy related to regional cooperation between Central Asian states, such as integrated water management and development of hydro-energy system, issues of diversification of hydrocarbons supply routes from the region to Europe and provision of energy security, etc.

    Issues of cooperation between the European Union and Tajikistan are analysed as a case study. State of affairs between some of the European Union member-states and Central Asian countries is characterised.

    The thesis also scrutinises other regional/international actors engaged in cooperation with Central Asia (such as China, Russia, the US, Shanghai Cooperation Organisation, etc.) and their potential for interaction with the European Union for more effective joint solution of the problems existing in the region is assessed.

    In the conclusion, development of cooperation between the European Union and Central Asian states is scrutinised, the problems and their possible solutions in this regard are analysed, and the recommendations for increasing effectiveness of cooperation between the two parties are presented.

    The European Union’s foreign policy in Central Asia is interpreted from perspective of the theories of international relations namely neorealism, neoliberalism and constructivism in the end of every chapter.

  • 142.
    Abdulhamidova, Nurangez
    Linköping University, Department of Management and Engineering.
    The European Union-Central Asia: in the light of the New Strategy2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Central Asia is a region strategically located at the crossroads of the two continents: Asia and Europe. The region is represented by five states (Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan) with different level of economic development and with the population amounting to over 60 million people. The region is rich in energy resources represented by oil, gas, coal and water resources.

    The thesis analyses, assesses and scrutinises one of the topical issues of the contemporary international relations - cooperation between the European Union and Central Asian states before and after adoption in June 2007 of the ‘European Union and Central Asia: Strategy for a New Partnership’,  an important political document in the history of relations between the two parties.

    The new stage of cooperation is analysed more comprehensively accentuating priorities set in the Strategy. Analysis of the current state of affairs is conducted concerning some important issues of the Strategy related to regional cooperation between Central Asian states, such as integrated water management and development of hydro-energy system, issues of diversification of hydrocarbons supply routes from the region to Europe and provision of energy security, etc.

    Issues of cooperation between the European Union and Tajikistan are analysed as a case study. State of affairs between the Central Asian states and the European Union Member States actively cooperating with these countries is characterised.

    The thesis also scrutinises other regional/international actors engaged in cooperation with Central Asia (such as China, Russia, the US, Shanghai Cooperation Organisation, etc.) and their potential for interaction with the European Union for more effective joint solution of the problems existing in the region is assessed.

    In the conclusion, development of cooperation between the European Union and Central Asian states is scrutinised, the problems and their possible solutions in this regard are analysed, and the recommendations for increasing effectiveness of cooperation between the two parties are presented.

    The European Union’s policy in Central Asia is interpreted from perspective of the theories of international relations namely neorealism, neoliberalism and constructivism in the research.

  • 143.
    Abdulla, Afrah
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Educational Sciences. Department of Social and Behavioural Studies, Division of Social Pedagogy and Sociology, Högskolan Väst, Trollhättan, Sweden.
    Readiness or resistance?: Newly arrived adult migrants' experiences, meaning making, and learning in Sweden2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    This thesis is about newly arrived adult migrants’ meaning making and learning in Swedish society during the two years’ introduction period, after they have received the residence permit. I have specifically studied Arabic speaking adults’ meaning making and learning, by carrying out observations and individual in-depth interviews with 12 migrants. The introduction period consists mainly of three so called introduction measures; the civic orientation course, Swedish for immigrants (SFI), and different work related activities, such as internship at different work places.

    The results show that etablering is about shaping the newly arrived adult migrants into ”good” citizens, through the introduction measures, among other things in the civic orientation course, which is regulated through the policy documents, and which so to say provides meaning to the newly arrived. The “good” citizen has some specific characteristics, which, roughly, are that he or she is independent (and advocates individuality), free, equality thinking, secularized, law-abiding (which includes being honest), responsible, and a “good” parent. These characteristics are expressed in different ways in the civic orientation course, for instance through the course material. The Swedish society is described as something desirable, and different from what is implied to be ”Arabic” values and ways of thinking. The idea of the “good” citizen appears to aim at constructing the adult migrants’ (and their families’) identity, something which many of the study’s respondents make a resistance to.

    As concerns the migrant’s new experiences, it is, for example, those which the migrant get through the contact with the Swedish Public Employment Service (SPES) that affect the meaning making in the new society. The meaning which most of the respondents have made of the SPES’s measures for them is that this authority only offers “prepackaged” solutions, and does not provide the help or support that they need. Also the experiences which the migrant has in the civic orientation course, and the meaning which ”old” migrants give to him or her, play a role when he or she makes meaning of Sweden and Swedes, and of his or her new life situation. Further, it has been shown that it is those experiences that the adult individual has been socialized through, and those which he or she has gained through work or education in his or her country of origin, which affect his or her meaning making in Sweden. It is mostly values which concern child upbringing and religion that lead to a certain understanding and construction of one’s new life. These values, when related to the values which are included in the ”good” citizen idea, also lead to either a resistance or a readiness towards the meaning giving that is embedded in the ”good” citizen notion.

  • 144.
    Abdulla, Afrah
    et al.
    Linköping University, Department of Behavioural Sciences and Learning. Linköping University, Faculty of Arts and Sciences.
    Risenfors, Signild
    Högskolan Väst.
    Kursen samhällsorientering för nyanlända: mobilisering och integration för deltagare2013In: Gemenskaper: socialpedagogiska perspektiv / [ed] Lisbeth Eriksson, Gunilla Nilsson, Lars A. Svensson, Göteborg: Daidalos, 2013, 117-138 p.Chapter in book (Other academic)
  • 145.
    Abdulla, Parosh Aziz
    et al.
    Department of Information Technology, Uppsala University, Sweden.
    Atig, Mohamed Faouzi
    Department of Information Technology, Uppsala University, Sweden.
    Chen, Yu-Fang
    Institute of Information Science, Academia Sinica, Taiwan.
    Holik, Lukas
    Faculty of Information Technology, Brno University of Technology, Czech Republic.
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Rümmer, Philipp
    Department of Information Technology, Uppsala University, Sweden.
    Stenman, Jari
    Department of Information Technology, Uppsala University, Sweden.
    String Constraints for Verification2014In: 26th International Conference on Computer Aided Verification (CAV 2014), Vienna, Austria, Jul. 9-12, 2014., Springer, 2014, 150-166 p.Conference paper (Refereed)
    Abstract [en]

    We present a decision procedure for a logic that combines (i) word equations over string variables denoting words of arbitrary lengths, together with (ii) constraints on the length of words, and on (iii) the regular languages to which words belong. Decidability of this general logic is still open. Our procedure is sound for the general logic, and a decision procedure for a particularly rich fragment that restricts the form in which word equations are written. In contrast to many existing procedures, our method does not make assumptions about the maximum length of words. We have developed a prototypical implementation of our decision procedure, and integrated it into a CEGAR-based model checker for the analysis of programs encoded as Horn clauses. Our tool is able to automatically establish the correctness of several programs that are beyond the reach of existing methods.

  • 146.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Sweden.
    Atig, Mohamed Faouzi
    Uppsala University, Sweden.
    Chen, Yu-Fang
    Academia Sinica, Taiwan.
    Leonardsson, Carl
    Uppsala University, Sweden.
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Automatic fence insertion in integer programs via predicate abstraction2012In: Static Analysis: 19th International Symposium, SAS 2012, Deauville, France, September 11-13, 2012. Proceedings / [ed] Antoine Miné, David Schmidt, Springer Berlin/Heidelberg, 2012, 164-180 p.Conference paper (Refereed)
    Abstract [en]

    We propose an automatic fence insertion and verification framework for concurrent programs running under relaxed memory. Unlike previous approaches to this problem, which allow only variables of finite domain, we target programs with (unbounded) integer variables. The problem is difficult because it has two different sources of infiniteness: unbounded store buffers and unbounded integer variables. Our framework consists of three main components: (1) a finite abstraction technique for the store buffers, (2) a finite abstraction technique for the integer variables, and (3) a counterexample guided abstraction refinement loop of the model obtained from the combination of the two abstraction techniques. We have implemented a prototype based on the framework and run it successfully on all standard benchmarks together with several challenging examples that are beyond the applicability of existing methods.

  • 147.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Sweden.
    Atig, Mohamed Faouzi
    Uppsala University, Sweden.
    Chen, Yu-Fang
    Academia Sinica, Taiwan.
    Leonardsson, Carl
    Uppsala University, Sweden.
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, The Institute of Technology.
    Counter-Example Guided Fence Insertion under TSO2012In: TACAS 2012, 2012Conference paper (Refereed)
    Abstract [en]

    We give a sound and complete fence insertion procedure for concurrentfinite-state programs running under the classical TSO memory model. Thismodel allows “write to read” relaxation corresponding to the addition of an unboundedstore buffer between each processor and the main memory. We introducea novel machine model, called the Single-Buffer (SB) semantics, and show thatthe reachability problem for a program under TSO can be reduced to the reachabilityproblem under SB. We present a simple and effective backward reachabilityanalysis algorithm for the latter, and propose a counter-example guided fence insertionprocedure. The procedure is augmented by a placement constraint thatallows the user to choose places inside the program where fences may be inserted.For a given placement constraint, we automatically infer all minimal setsof fences that ensure correctness. We have implemented a prototype and run itsuccessfully on all standard benchmarks together with several challenging examplesthat are beyond the applicability of existing methods.

  • 148.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Sweden.
    Atig, Mohamed Faouzi
    Uppsala University, Sweden.
    Chen, Yu-Fang
    Academia Sinica, Taiwan.
    Leonardsson, Carl
    Uppsala University, Sweden.
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Memorax, a Precise and Sound Tool for Automatic Fence Insertion under TSO2013In: Tools and Algorithms for the Construction and Analysis of Systems: 19th International Conference, TACAS 2013, Held as Part of the European Joint Conferences on Theory and Practice of Software, ETAPS 2013, Rome, Italy, March 16-24, 2013. Proceedings, Springer Berlin/Heidelberg, 2013, 530-536 p.Conference paper (Refereed)
    Abstract [en]

    We introduce MEMORAX, a tool for the verification of control state reachability (i.e., safety properties) of concurrent programs manipulating finite range and integer variables and running on top of weak memory models. The verification task is non-trivial as it involves exploring state spaces of arbitrary or even infinite sizes. Even for programs that only manipulate finite range variables, the sizes of the store buffers could grow unboundedly, and hence the state spaces that need to be explored could be of infinite size. In addition, MEMORAX in- corporates an interpolation based CEGAR loop to make possible the verification of control state reachability for concurrent programs involving integer variables. The reachability procedure is used to automatically compute possible memory fence placements that guarantee the unreachability of bad control states under TSO. In fact, for programs only involving finite range variables and running on TSO, the fence insertion functionality is complete, i.e., it will find all minimal sets of memory fence placements (minimal in the sense that removing any fence would result in the reachability of the bad control states). This makes MEMORAX the first freely available, open source, push-button verification and fence insertion tool for programs running under TSO with integer variables.

  • 149.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University.
    Atig, Mohammed Faouzi
    Uppsala University.
    Ganjei, Zeinab
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Zhu, Yunyun
    Uppsala University.
    Verification of Cache Coherence Protocols wrt. Trace Filters2015Conference paper (Refereed)
    Abstract [en]

    We address the problem of parameterized verification of cache coherence protocols for hardware accelerated transactional memories. In this setting, transactional memories leverage on the versioning capabilities of the underlying cache coherence protocol. The length of the transactions, their number, and the number of manipulated variables (i.e., cache lines) are parameters of the verification problem. Caches in such systems are finite-state automata communicating via broadcasts and shared variables. We augment our system with filters that restrict the set of possible executable traces according to existing conflict resolution policies. We show that the verification of coherence for parameterized cache protocols with filters can be reduced to systems with only a finite number of cache lines. For verification, we show how to account for the effect of the adopted filters in a symbolic backward reachability algorithm based on the framework of constrained monotonic abstraction. We have implemented our method and used it to verify transactional memory coherence protocols with respect to different conflict resolution policies.

  • 150.
    Abdulla, Parosh Aziz
    et al.
    Uppsala University, Sweden.
    Dwarkadas, Sandhya
    University of Rochester, U.S.A..
    Rezine, Ahmed
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Shriraman, Arrvindh
    Simon Fraser University, Canada.
    Zhu, Yunyun
    Uppsala University, Sweden.
    Verifying Safety and Liveness for the FlexTM Hybrid Transactional Memory2013In: Design, Automation & Test in Europe (DATE 2013), Grenoble, France, March 18-22, 2013., IEEE , 2013, 785-790 p.Conference paper (Refereed)
    Abstract [en]

    We consider the verification of safety (strict se- rializability and abort consistency) and liveness (obstruction and livelock freedom) for the hybrid transactional memory framework FLEXTM. This framework allows for flexible imple- mentations of transactional memories based on an adaptation of the MESI coherence protocol. FLEXTM allows for both eager and lazy conflict resolution strategies. Like in the case of Software Transactional Memories, the verification problem is not trivial as the number of concurrent transactions, their size, and the number of accessed shared variables cannot be a priori bounded. This complexity is exacerbated by aspects that are specific to hardware and hybrid transactional memories. Our work takes into account intricate behaviours such as cache line based conflict detection, false sharing, invisible reads or non-transactional instructions. We carry out the first automatic verification of a hybrid transactional memory and establish, by adopting a small model approach, challenging properties such as strict serializability, abort consistency, and obstruction freedom for both an eager and a lazy conflict resolution strategies. We also detect an example that refutes livelock freedom. To achieve this, our prototype tool makes use the latest antichain based techniques to handle systems with tens of thousands of states.

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