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Ljungman, Anders
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Publications (10 of 17) Show all publications
Nosratabadi, A. R., Graff, P., Karlsson, H., Ljungman, A. & Leanderson, P. (2019). Use of TEOM monitors for continuous long-term sampling of ambient particles for analysis of constituents and biological effects. Air quality, atmosphere and health, 12(2), 161-171
Open this publication in new window or tab >>Use of TEOM monitors for continuous long-term sampling of ambient particles for analysis of constituents and biological effects
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2019 (English)In: Air quality, atmosphere and health, ISSN 1873-9318, E-ISSN 1873-9326, Vol. 12, no 2, p. 161-171Article in journal (Refereed) Published
Abstract [en]

Many countries have implemented exposure limits for the concentration of ambient particular matter and do therefore have to monitor their concentration. This could be performed with TEOM monitors (Tapered Element Oscillating Microbalance-monitors) that contain a filter on which particles are collected. These filters are regularly exchanged for new ones. The aim of this study was to test the feasibility of collecting used filters from monitors at different locations and establishing a method to extract particles and then study them with respect to their ability to generate oxidants, their endotoxin content, and ability to activate inflammatory cells. Filters from nine geographically spread locations in Sweden were collected during a 21-month period by local technicians who then sent them to the laboratory where they were extracted and analyzed. The procedure to let local technicians perform the filter exchange and send used TEOM filters to the laboratory worked well. A method was established in which pyrogen-free water was used to extract particles that then were aliquoted and stored for later analysis. Particulate matter (PM10) from different locations showed both a considerable seasonal and spatial-dependent difference with respect to oxidative potential (oxidize glutathione), endotoxin content, and ability to activate blood monocytes to release interleukin-1β. This study shows that, instead of discarding TEOM filters, they can be collected and extracted so that particles that have been sampled in a standardized way could be analyzed with respect to variables that reflect their toxicity. This could be done at a low cost. In combination with information about the ambient particle concentration, such information could be helpful in the evaluation of differences in the risk of breathing air at various locations.

Place, publisher, year, edition, pages
Springer Netherlands, 2019
Keywords
Air pollution, TEOM monitor, Ambient particles, Surface reactivity, Endotoxin, Seasonal variation
National Category
Occupational Health and Environmental Health
Identifiers
urn:nbn:se:liu:diva-154602 (URN)10.1007/s11869-018-0638-5 (DOI)000458121600004 ()2-s2.0-85056389584 (Scopus ID)
Available from: 2019-02-21 Created: 2019-02-21 Last updated: 2019-03-15Bibliographically approved
Szabó, Z., Harangi, M., Nylander, E., Ljungman, A., Theodorsson, A., Ahn, H. & Davidsson, B. (2015). How students perceive problem-based learning (PBL) group tutorials at a Swedish Medical College. Med Ed Publish, 6(17)
Open this publication in new window or tab >>How students perceive problem-based learning (PBL) group tutorials at a Swedish Medical College
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2015 (English)In: Med Ed Publish, ISSN 2312-7996, Vol. 6, no 17Article in journal (Refereed) Published
Abstract [en]

Introduction: student perception of problem-based learning (PBL) group tutorials was investigated at a Swedish University Medical College 27 years after the introduction of PBL into the curriculum.

Methods: a survey questionnaire comprising 43 questions answered on a Likert-type scale, together with one open question was used. The questionnaire was distributed to all 821 students taking part in the Linköping University medical program at the beginning of the Spring Term 2013. The results were subjected to explorative factor analysis, descriptive statistics and ANOVA. Responses to the open question where analyzed qualitatively by categorization.

Results: 84 per cent of the 821 students completed the survey. Four factors describing student perception were identified: 1) PBL as a method of learning; 2) the tutor’s role; 3) PBL, stress and feelings of insecurity; and 4) traditional teaching methods within the PBL curriculum. The Cronbach´s alpha value was 0,788 overall. Two hundred and seventy-six students answered the open question declaring that they would appreciate more precise aims and objectives, smaller tutorial groups, and more formal lectures.

Conclusions: the results of this study on PBL group tutorials, as seen from the student’s perspective, stress the importance of tutorial quality, tutor competence, tutorial group size and the quality and aims of the curriculum. Too much emphasis on the teacher’s research merits against the educational ones, and the inability to adapt to the needs and wishes of new generations of students seems a probable cause for the erosion of PBL.

Keywords
Problem-based learning, group work, tutors, self-directed learning
National Category
Clinical Medicine
Identifiers
urn:nbn:se:liu:diva-122164 (URN)10.15694/mep.2015.006.0017 (DOI)
Available from: 2015-10-22 Created: 2015-10-22 Last updated: 2018-02-21
Karlsson, H., Ljunggren, S., Ahrén, M., Ghafouri, B., Uvdal, K., Lindahl, M. & Ljungman, A. (2012). Two-dimensional gel electrophoresis and mass spectrometry in studies of nanoparticle-protein interactions. In: Sameh Magdeldin (Ed.), Gel electrophoresis-Advanced Techniques: (pp. 1-32). Rijeka, Croatia: In Tech
Open this publication in new window or tab >>Two-dimensional gel electrophoresis and mass spectrometry in studies of nanoparticle-protein interactions
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2012 (English)In: Gel electrophoresis-Advanced Techniques / [ed] Sameh Magdeldin, Rijeka, Croatia: In Tech , 2012, p. 1-32Chapter in book (Other academic)
Abstract [en]

Over the years a number of epidemiological studies have shown that PM from combustion sources such as motor vehicles contributes to respiratory and cardiovascular morbidity and mortality.Especially so do the ultra-fine particles (UFPs) with a diameter less than 0.1 micrometer.UFPs from combustion engines are capable to translocate over the alveolar–capillary barrier.  When nano-sized PM (nanoparticles, NP), which are small enough to enter the blood stream, do so they are likely to interact with plasma proteins and this protein-NP interaction will probably affect the fate of and the effects caused by the NPs in the human body. Here, by using a proteomic approach, we present results showing that several proteins indeed are associated to NPs that have in vitro been introduced to human blood plasma.

Place, publisher, year, edition, pages
Rijeka, Croatia: In Tech, 2012
Keywords
Proteins, Nanoparticles, Gelelectrophoresis
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-78397 (URN)10.5772/38085 (DOI)978-953-51-0457-5 (ISBN)
Available from: 2012-06-11 Created: 2012-06-11 Last updated: 2015-05-29Bibliographically approved
Karlsson, H., Lindbom, J., Ghafouri, B., Lindahl, M., Tagesson, C., Gustafsson, M. & Ljungman, A. G. (2011). Wear Particles from Studded Tires and Granite Pavement Induce Pro-inflammatory Alterations in Human Monocyte-Derived Macrophages: A Proteomic Study.. Chemical Research in Toxicology, 24, 45-53
Open this publication in new window or tab >>Wear Particles from Studded Tires and Granite Pavement Induce Pro-inflammatory Alterations in Human Monocyte-Derived Macrophages: A Proteomic Study.
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2011 (English)In: Chemical Research in Toxicology, ISSN 0893-228X, E-ISSN 1520-5010, Vol. 24, p. 45-53Article in journal (Refereed) Published
Abstract [en]

Airborne particulate matter is considered to be one of the environmental contributors to the mortality in cancer, respiratory, and cardiovascular diseases. For future preventive actions, it is of major concern to investigate the toxicity of defined groups of airborne particles and to clarify their pathways in biological tissues. To expand the knowledge beyond general inflammatory markers, this study examined the toxicoproteomic effects on human monocyte derived macrophages after exposure to wear particles generated from the interface of studded tires and a granite-containing pavement. As comparison, the effect of endotoxin was also investigated. The macrophage proteome was separated using two-dimensional gel electrophoresis. Detected proteins were quantified, and selected proteins were identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry. Among analyzed proteins, seven were significantly decreased and three were increased by exposure to wear particles as compared to unexposed control cells. Endotoxin exposure resulted in significant changes in the expression of six proteins: four decreased and two increased. For example, macrophage capping protein was significantly increased after wear particle exposure only, whereas calgizzarin and galectin-3 were increased by both wear particle and endotoxin exposure. Overall, proteins associated with inflammatory response were increased and proteins involved in cellular functions such as redox balance, anti-inflammatory response, and glycolysis were decreased. Investigating the effects of characterized wear particles on human macrophages with a toxicoproteomic approach has shown to be useful in the search for more detailed information about specific pathways and possible biological markers.

Place, publisher, year, edition, pages
American Chemical Society, 2011
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-64206 (URN)10.1021/tx100281f (DOI)000286130100006 ()21117676 (PubMedID)
Available from: 2011-01-14 Created: 2011-01-14 Last updated: 2017-12-11Bibliographically approved
Ljungman, A. & Silén, C. (2008). Examination involving students as peer examiners. Assessment & Evaluation in Higher Education, 33(3), 289-300
Open this publication in new window or tab >>Examination involving students as peer examiners
2008 (English)In: Assessment & Evaluation in Higher Education, ISSN 0260-2938, E-ISSN 1469-297X, Vol. 33, no 3, p. 289-300Article in journal (Refereed) Published
Abstract [en]

The main interest in this article is students' involvement in assessment as a part of growth towards self-directedness in learning. In order to enhance students' development of autonomy in learning, a project involving 'older' students as peer examiners for 'younger' students was designed and carried out. Students in the sixth semester in a PBL-based Master's program of Medical Biology participated, together with faculty, as examiners of fifth-semester students. The examination and the assessment situation was carefully designed based on learning theories, empirical evidence and experiences underpinning student-centred learning, especially in the form of PBL used at the faculty. The project was evaluated and analysed in order to understand students' learning processes related to the responsibility for assessing peers. The situation of the peer examiners was interpreted based on their own experiences with statements from the students assessed and faculty involved in the assessment. Evaluations from six occasions, spring and fall, 2003-2005, were included in the study. The findings suggest that involving students in assessment as equal partners with faculty makes it is possible for students to apprehend the metacognitive competences needed to be responsible and autonomous in learning. The peer examiners experience motivation to learn about learning, they acquire tacit knowledge about assessment and they learn through being involved and trusted. The student-centred educational context, which requires responsibility throughout the programme, is recognized as very important.   

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-43623 (URN)10.1080/02602930701293306 (DOI)74443 (Local ID)74443 (Archive number)74443 (OAI)
Note
This is an electronic version of an article published in: Anders Ljungman and Charlotte Silén, Examination involving students as peer examiners, 2008, Assessment & Evaluation in Higher Education, (33), 3, 289-300. Assessment & Evaluation in Higher Education is available online at informaworldTM: http://dx.doi.org/10.1080/02602930701293306 Copyright: Taylor & Francis http://www.tandf.co.uk/journals/default.asp Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Gustafsson, M., Blomqvist, G., Gudmundsson, A., Dahl, A., Swietlicki, E., Bohgard, M., . . . Ljungman, A. (2008). Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material. Science of the Total Environment, 393(2-3), 226-240
Open this publication in new window or tab >>Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material
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2008 (English)In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 393, no 2-3, p. 226-240Article in journal (Refereed) Published
Abstract [en]

In regions where studded tyres and traction material are used during winter, e.g. the Nordic countries, northern part of USA, Canada, and Japan, mechanically generated particles from traffic is the main reason for high particle concentrations in busy street- and road environments. In many Nordic municipalities the European environmental quality standard for inhalable particles (PM10) is exceeded due to these particles. In this study, particles from the wear of studded and studless friction tyres on two pavements and traction sanding were generated using a road simulator. The particles were characterized using particle sizers, PIXE and electron microscopy. Cell studies were conducted on particles sampled from the tests with studded tyres and compared with street environment, diesel exhaust and subway PM10, respectively. The results show that in the road simulator, where resuspension is minimised, studded tyres produce tens of times more particles than friction tyres. Chemical analysis of the sampled particles shows that the generated wear particles consists almost entirely of minerals from the pavement stone material, but also that S is enriched for the sub-micron particles and that Zn is enriched for friction tyres for all particles sizes. The chemical data can be used for source identification and apportionment in urban aerosol studies. A mode of ultra-fine particles was also present and is hypothesised to originate in the tyres. Further, traction material properties affect PM10 emission. The inflammatory potential of the particles from wear of pavements seems to depend on type of pavement and can be at least as potent as diesel exhaust particles. The results implies that there is a need and a good potential to reduce particle emission from pavement wear and winter time road and street operation by adjusting both studded tyre use as well as pavement and traction material properties.

Place, publisher, year, edition, pages
Institutionen för klinisk och experimentell medicin, 2008
Keywords
PM10, PARTICLES, TYRES, TRACTION MATERIAL, ROAD SIMULATOR, CELL STUDY, ROAD WEAR, TRAFFIC EMISSION
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-11344 (URN)10.1016/j.scitotenv.2007.12.030 (DOI)
Note
Original publication: Mats Gustafsson, Göran Blomqvist, Anders Gudmundsson, Andreas Dahl, Erik Swietlicki, Mats Boghard, John Lindbom, Anders Ljungman, Properties and toxicological effects of particles from the interaction between tyres, road pavement and winter traction material, 2008, Science of the Total Environment, (393), 2-3, 226-240. http://dx.doi.org/10.1016/j.scitotenv.2007.12.030. Copyright: Elsevier B.V., http://www.elsevier.com/Available from: 2008-04-04 Created: 2008-04-04 Last updated: 2017-12-13
Lindbom, J., Gustafsson, M., Blomqvist, G., Dahl, A., Gudmundsson, A., Swietlicki, E. & Ljungman, A. (2007). Wear particles generated from studded tires and pavement induces inflammatory reactions in mouse macrophage cells. Chemical Research in Toxicology, 20(6), 937-946
Open this publication in new window or tab >>Wear particles generated from studded tires and pavement induces inflammatory reactions in mouse macrophage cells
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2007 (English)In: Chemical Research in Toxicology, ISSN 0893-228X, E-ISSN 1520-5010, Vol. 20, no 6, p. 937-946Article in journal (Refereed) Published
Abstract [en]

Health risks associated with exposure to airborne particulate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. These health risks are of increasing concern in society, and to protect public health, a clarification of the toxic properties of particles from different sources is of importance. Lately, wear particles generated from traffic have been recognized as a major contributing source to the overall particle load, especially in the Nordic countries where studded tires are used. The aim of this study was to further investigate and compare the ability to induce inflammatory mediators of different traffic-related wear particles collected from an urban street, a subway station, and studded tire-pavement wear. Inflammatory effects were measured as induction of nitric oxide (NO), IL-6, TNF-α, arachidonic acid (AA), and lipid peroxidation after exposure of the murine macrophage like cell line RAW 264.7. In addition, the redox potential of the particles was measured in a cell-free system. The results show that all particles tested induce IL-6, TNF-α, and NO, and those from the urban street were the most potent ones. In contrast, particles collected from a subway station were most potent to induce lipid peroxidation, A A release, and formation of ROS. Particles from studded tire-pavement wear, generated using a road simulator, were able to induce inflammatory cytokines, NO, lipid peroxidation, and ROS formation. Interestingly, particles generated from pavement containing granite as the main stone material were more potent than those generated from pavement containing quartzite as the main stone material.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-38582 (URN)10.1021/tx700018z (DOI)44807 (Local ID)44807 (Archive number)44807 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Karlsson, H. L., Ljungman, A., Lindbom, J. & Möller, L. (2006). Comparison of genotoxic and inflammatory effects of particles generated by wood combustion, a road simulator and collected from street and subway. Toxicology Letters, 165(3), 203-211
Open this publication in new window or tab >>Comparison of genotoxic and inflammatory effects of particles generated by wood combustion, a road simulator and collected from street and subway
2006 (English)In: Toxicology Letters, ISSN 0378-4274, E-ISSN 1879-3169, Vol. 165, no 3, p. 203-211Article in journal (Refereed) Published
Abstract [en]

The health effects of exposure to airborne particles are of increasing concern in society. In order to protect public health, a clarification of the toxic properties of particles from different sources is of importance. The aim of this study was to investigate and compare the genotoxicity and the ability to induce inflammatory mediators of nine different particle types from wood and pellets combustion, from tire–road wear and collected from an urban street and a subway station. The comet assay was used to assess genotoxicity after exposure of the human lung cell line A549. Inflammatory effects were measured as induction of IL-6, IL-8 and TNF-α after exposure of human macrophages. We found that all particles tested caused DNA damage and those from the subway caused more damage than the other particles (p < 0.001) likely due to redox-active iron. In contrast, particles collected from an urban street were most potent to induce inflammatory cytokines. Particles from tire–road wear collected using a road simulator were genotoxic and able to induce cytokines. Finally, more effective combustion of wood led to less emission of particles, but those emitted did not show less toxicity in this study.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-35153 (URN)10.1016/j.toxlet.2006.04.003 (DOI)25306 (Local ID)25306 (Archive number)25306 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Lindbom, J., Gustafsson, M., Blomqvist, G., Dahl, A., Gudmundsson, A., Swietlicki, E. & Ljungman, A. (2006). Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages. Chemical Research in Toxicology, 19(4), 521-530
Open this publication in new window or tab >>Exposure to wear particles generated from studded tires and pavement induces inflammatory cytokine release from human macrophages
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2006 (English)In: Chemical Research in Toxicology, ISSN 0893-228X, E-ISSN 1520-5010, Vol. 19, no 4, p. 521-530Article in journal (Refereed) Published
Abstract [en]

Health risks associated with exposure to airborne paniculate matter (PM) have been shown epidemiologically as well as experimentally, pointing to both respiratory and cardiovascular effects. Lately, wear particles generated from traffic have been recognized to be a major contributing source to the overall particle load, especially in the Nordic countries were studded tires are used. In this work, we investigated the inflammatory effect of PM10 generated from the wear of studded tires on two different types of pavement. As comparison, we also investigated PM10 from a traffic-intensive street, a subway station, and diesel exhaust particles (DEP). Human monocyte-derived macrophages, nasal epithelial cells (RPMI 2650), and bronchial epithelial cells (BEAS-2B) were exposed to the different types of particles, and the secretion of IL-6, IL-8, IL-10, and TNF-α into the culture medium was measured. The results show a significant release of cytokines from macrophages after exposure for all types of particles. When particles generated from asphalt/granite pavement were compared to asphalt/quartzite pavement, the granite pavement had a significantly higher capacity to induce the release of cytokines. The granite pavement particles induced cytokine release at the same magnitude as the street particles did, which was higher than what particles from both a subway station and DEP did. Exposure of epithelial cells to PM 10 resulted in a significant increase of TNF-α secreted from BEAS-2B cells for all types of particles used (DEP was not tested), and the highest levels were induced by subway particles. None of the particle types were able to evoke detectable cytokine release from RPMI 2650 cells. The results indicate that PM10 generated by the wear of studded tires on the street surface is a large contributor to the cytokine-releasing ability of particles in traffic-intensive areas and that the type of pavement used is important for the level of this contribution. Furthermore, the airway inflammatory potential of wear particles from tires and pavement might be of a greater magnitude than that of DEP.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-35160 (URN)10.1021/tx0503101 (DOI)25445 (Local ID)25445 (Archive number)25445 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
Dahl, A., Gharibi, A., Swietlicki, E., Gudmundsson, A., Bohgard, M., Ljungman, A., . . . Gustafsson, M. (2006). Traffic-generated emissions of ultrafine particles from pavement-tire interface. Atmospheric Environment, 40(7), 1314-1323
Open this publication in new window or tab >>Traffic-generated emissions of ultrafine particles from pavement-tire interface
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2006 (English)In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 40, no 7, p. 1314-1323Article in journal (Refereed) Published
Abstract [en]

In a road simulator study, a significant source of sub-micrometer fine particles produced by the road-tire interface was observed. Since the particle size distribution and source strength is dependent on the type of tire used, it is likely that these particles largely originate from the tires, and not the road pavement. The particles consisted most likely of mineral oils from the softening filler and fragments of the carbon-reinforcing filler material (soot agglomerates). This identification was based on transmission electron microscopy studies of collected ultrafine wear particles and on-line thermal treatment using a thermodesorber. The mean particle number diameters were between 15-50 nm, similar to those found in light duty vehicle (LDV) tail-pipe exhaust. A simple box model approach was used to estimate emission factors in the size interval 15-700 nm. The emission factors increased with increasing vehicle speed, and varied between 3.7×1011 and 3.2×10 12 particles vehicle-1 km-1 at speeds of 50 and 70 km h-1. This corresponds to between 0.1-1% of tail-pipe emissions in real-world emission studies at similar speeds from a fleet of LDV with 95% gasoline and 5% diesel-fueled cars. The emission factors for particles originating from the road-tire interface were, however, similar in magnitude to particle number emission factors from liquefied petroleum gas-powered vehicles derived in test bench studies in Australia 2005. Thus the road-tire interface may be a significant contributor to particle emissions from ultraclean vehicles. © 2005 Elsevier Ltd. All rights reserved.

National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-35154 (URN)10.1016/j.atmosenv.2005.10.029 (DOI)25307 (Local ID)25307 (Archive number)25307 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2017-12-13
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