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  • 1. Danilczuk, M.
    et al.
    Gustafsson, Håkan
    Linköping University, Department of Medicine and Health Sciences, Radiation Physics . Linköping University, Faculty of Health Sciences.
    Sastry, M.D.
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Lund, Eva
    Linköping University, Department of Medicine and Health Sciences, Radiation Physics . Linköping University, Faculty of Health Sciences.
    Lund, Anders
    Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics . Linköping University, The Institute of Technology.
    Ammonium Dithionate – a New Material for Highly Sensitive EPR Dosimetry2008In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 69, no 1, p. 18-21Article in journal (Refereed)
    Abstract [en]

    Polycrystalline ammonium dithionate has been examined for its radiation response in the low dose range (< 5 Gy) using EPR technique. The •SO3- radical ion was detected as a single EPR line with a peak-to-peak derivative width of ca. 0.44 mT in irradiated samples and its intensity was found to vary linearly with dose. At equal and moderate settings of microwave power and modulation amplitude ammonium dithionate was at least 7 times more sensitive than L-alanine which is the most common EPR dosimeter standard. Pulse experiments were performed on the powder samples to obtain the longitudinal relaxation time. These and microwave saturation experiments served to indicate the optimal microwave power to be applied during measurements as an EPR dosimeter for best sensitivity of this material. It is thus claimed that ammonium dithionate has excellent potential to become an EPR dosimeter with a low limit of the measurable dose for cases where tissue equivalence is not required or can be corrected for.

  • 2. Danilczuk, M.
    et al.
    Lund, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    Sadlo, J
    Yamada, H.
    Michalik, J.
    Conduction electron spin resonance of small silver particles2006In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 63, no 1, p. 189-191Article in journal (Refereed)
    Abstract [en]

    Electron spin resonance (ESR) spectroscopy has been used to study the conduction electron spin resonance (CESR) of small silver particles stabilized in dehydrated Ag-rho zeolite. Silver particles were produced by hydrogen reduction at elevated temperatures and diameter of the stabilized particles was calculated based on the linewidth of CESR signal using Kawabata theory. © 2005 Elsevier B.V. All rights reserved.

  • 3.
    Hu, Jiwen
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Zhang, Xin
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Liu, Tingting
    Tongji Univ, Peoples R China.
    Gao, Hong-Wen
    Tongji Univ, Peoples R China.
    Lu, Senlin
    Shanghai Univ, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering. Shanghai Univ, Peoples R China.
    Ratiometric fluorogenic determination of endogenous hypochlorous acid in living cells2019In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 219, p. 232-239Article in journal (Refereed)
    Abstract [en]

    Hypochlorous acid (HClO) is one of the most important ROS (reactive oxygen species) and common pollutant in tap-water. However, the determination of HClO with fast response and high sensitivity/selectivity is still an urgent demanding. Here we fabricated a ratiometric fluorescent probe RC based on TBET (through-bond energy transfer) on the platform of coumarin and rhodamine with the thiosemicarbazide group as the linker. This probe could display the characteristic fluorescence emission of coumarin. Upon addition of HClO, the linker was reacted into an oxadiazole, resulting in the opening of spiro-ring of rhodamine. The resultant then gives ratiometric fluorogenic changes. The probe exhibits fast response and high selectivity and sensitivity towards HClO with a low limit of detection (similar to 140 nM). Eventually, RC is successfully applicated for determining spiked HClO in water samples and imaging endogenous HClO in living cells. (C) 2019 Published by Elsevier B.V.

  • 4. Komaguchi, K
    et al.
    Matsubara, Y
    Shiotani, M
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radiation Physics.
    Lund, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radiation Physics. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Radiation Physics.
    Lund, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    An ESR and ENDOR study of irradiated 6Li-formate2007In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 66, no 3, p. 754-760Article in journal (Refereed)
    Abstract [en]

    Lithium formate (6LiOOCH·H2O), 95% 6Li enrichment, combined with an exchange of crystallization water with D2O was investigated. The ESR spectrum of the radiation induced free radicals stable at room temperature consists of a singlet with a narrow line width, 0.92 mT. 6Li has smaller magnetic moment and nuclear spin, which resulted in the narrower line width accompanied with an increase in peak amplitude. In comparison with lithium formate with natural isotopic composition, 6Li (7.5%, I = 1) and 7Li (92.5%, I = 3/2), the sensitivity was increased by a factor of two. With optimised spectrometer settings 6Li formate had seven times higher sensitivity compared to alanine. Therefore this material is proposed as a dosimeter material in a dose range down to 0.1 Gy. The g and the 13C-hyperfine (hf) tensors of the CO2- radical anion, major paramagnetic products, were evaluated to be g = (2.0037, 1.9975, 2.0017), and A(13C) = (465.5, 447.5, 581.3) MHz for polycrystalline samples at room temperature. Furthermore, the 1H-hf and 6Li-hf tensors observed for the surroundings of CO2- by ENDOR technique were in fairly good agreement with DFT calculations. The CO2- radicals are found to be so stable that the formate is applicable to the ESR dosimetry, because of fully relaxing in a fully relaxed geometrical structure of the CO2- component and remaining tight binding with the surroundings after the H atom detachment from HCO2-. © 2006 Elsevier B.V. All rights reserved.

  • 5. Komaguchi, K.
    et al.
    Nomura, K.
    Shiotani, M.
    Lund, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    Jansson, M.
    Lunell, S
    ESR and theoretical studies of trimer radical cations of coronene2006In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 63, no 1, p. 76-84Article in journal (Refereed)
    Abstract [en]

    Highly resolved ESR spectra of monomer, dimer and trimer radical cations of coronene (C24H12) were observed at room temperature for a solution of 1,1,1,3,3,3-hexafluoro-2-propan-2-ol (HFP) containing thallium(III) trifluoroacetate as oxidant. The spectra consisting of multiple lines with isotropic 1H-hyperfine splitting (hfs) constants of 0. 0766 mT (24H) and 0.013 mT (6H) were attributable to a mixture of the dimer with the trimer radical cations, (C24H12)2+ and (C24H12)3+. For (C24H12)2+, the 1H-hfs constant agreed well with the reported value, 0.077 mT. However, for (C 24H12)3+, the values were significantly different from the reported ones, 0.117 mT (12H) and 0.020 mT (24H), by Ohya Nishiguchi et al. [H. Ohya-Nishiguchi, H. Ide, N. Hirota, Chem. Phys. Lett. 66 (1979) 581], but rather similar to those reported by Willigen et al. [H. van Willigen, E. De Boer, J.T. Cooper, W.F. Forbes, J. Chem . Phys. 49 (1968) 1190]. In conflict with Willigen's report, however, no ESR line broadening which has been ascribed to a low stationary concentration of (C 24H12)3+ was detected. Based on ab initio MO calculations for benzene as a compact model of C24H 12, the structure of (C24H12)3+ was investigated in terms of the observed 1H-hfs constants. A staggered sandwich C2v structure was suggested being at the "global" minimum for the benzene trimer cation. In the structure, the unpaired electron spin is predominantly localized to the central ring, which is qualitatively in agreement with the previous ESR results of (C 24H12)3+ by Ohya-Nishiguchi et al. In addition, as a "local" minimum, the benzene trimer was indicated to have a slipped sandwich Cs structure, which is less stable by ca. 19 kJ mol-1 than the "global" minimum. In this structure, the unpaired electron spin was nearly equally distributed on both the central and one of the two side C24H12 molecules. The observed 1H-hfs constants were possibly attributable to the (C 24H12)3+ cation with the analogous slipped sandwich Cs structure.

  • 6.
    Lund, Anders
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics. Linköping University, The Institute of Technology.
    Andersson, Peter
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Eriksson, J.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Hallin, J.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Johansson, T.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Jonsson, R.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Löfgren, H.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Paulin, C.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Tell, A.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Automatic fitting procedures for EPR spectra of disordered systems: matrix diagonalization and perturbation methods applied to fluorocarbon radicals2008In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 69, no 5, p. 1294-1300Article in journal (Refereed)
    Abstract [en]

    Two types of automatic fitting procedures for EPR spectra of disordered systems have been developed, one based on matrix diagonalisation of a general spin Hamiltonian, the other on 2nd order perturbation theory. The first program is based on a previous Fortran code complemented with a newly written interface in Java to provide user-friendly in- and output. The second is intended for the special case of free radicals with several relatively weakly interacting nuclei, in which case the general method becomes slow. A least squares’ fitting procedure utilizing analytical or numerical derivatives of the theoretically calculated spectrum with respect to the g-and hyperfine structure (hfs) tensors was used to refine those parameters in both cases. ‘Rigid limit’ ESR spectra from radicals in organic matrices and in polymers, previously studied experimentally at low temperature, were analysed by both methods. Fluoro-carbon anion radicals could be simulated, quite accurately with the exact method, whereas automatic fitting on e.g. the c-C4F8- anion radical is only feasible with the 2nd order approximative treatment. Initial values for the 19F hfs tensors estimated by DFT calculations were quite close to the final. For neutral radicals of the type XCF2CF2• the refinement of the hfs tensors by the exact method worked better than the approximate. The reasons are discussed. The ability of the fitting procedures to recover the correct magnetic parameters of disordered systems was investigated by fittings to synthetic spectra with known hfs tensors. The exact and the approximate methods are concluded to be complementary, one being general, but limited to relatively small systems, the other being a special treatment, suited for S=½ systems with several moderately large hfs.

  • 7.
    Lund, Anders
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics. Linköping University, The Institute of Technology.
    Danilczuk, Marek
    Institute Nucl Chemistry and Technology, Poland .
    Monomer- and polymer radicals of vinyl compounds: EPR and DFT studies of geometric and electronic structures in the adsorbed state2012In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 98, p. 367-377Article in journal (Refereed)
    Abstract [en]

    Electron paramagnetic resonance (EPR) spectroscopy was applied to study the paramagnetic species formed from styrene, 1,1-diphenylethylene, alpha-methylstyrene, beta-methylstyrene and methylmethacrylate adsorbed on amorphous silica gel after gamma-irradiation at 77 K. Radicals formed by the hydrogen atom addition at the vinyl group of the monomers were observed in all samples. The hydrogen atoms were shown to originate to a large extent from the adsorbent by using silica gel with deuterated silanol groups. An EPR spectrum assigned to a propagating radical was observed at increased temperature for samples containing methylmethacrylate (MMA). The structures of the adsorption complexes, the respective hyperfine splitting constants and the adsorption energies were calculated by applying OFF quantum chemical methods. The reaction between an MMA molecule and the MMA radical and the structure of the propagating radical was modeled. The calculated hyperfine splitting constants for all radicals confirmed the assignment of the experimental spectra.

  • 8.
    Lund, Anders
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiation Physics .
    Maruani, J.
    Laboratoire de Chimie Physique, UPMC and CNRS, 75005 Paris, France.
    Shiotani, M.
    Department of Applied Chemistry, Graduate School of Engineering, Hiroshima University, Higashi-Hiroshima 739-8527, Japan.
    Automatic fitting to 'powder' EPR spectra of coupled paramagnetic species employing Feynman's theorem2006In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 63, no 4, p. 830-835Article in journal (Refereed)
    Abstract [en]

    A previous automatic fitting procedure of EPR spectra has been extended with the purpose to characterise coupled paramagnetic complexes in powders and frozen solutions. The theoretical EPR spectra were obtained by matrix diagonalization of a general spin Hamiltonian. A least-squares fitting procedure using analytical derivatives of the calculated spectrum with respect to the spectroscopic, fine structure, nuclear quadrupole, electron-electron, and hyperfine coupling tensors was used to refine those parameters. The powder spectra of matrix isolated CF3 and RCF2CF2 radicals, previously measured at low temperature, were reanalysed with this method. A theoretically modeled complex consisting of a Cu2+ ion, featuring an axially symmetric g-tensor and 63Cu hyperfine structure anisotropy, and a free radical located at different orientations, with respect to the symmetry axis of the Cu2+ ion, was examined in order to investigate the possibility to recover the magnetic parameters of the separate units and the magnetic couplings between them. © 2005 Elsevier B.V. All right reserved.

  • 9.
    Lund, Anders
    et al.
    Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics . Linköping University, The Institute of Technology.
    Olsson, Sara
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radio Physics.
    Bonora, M
    Lund, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radio Physics.
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radio Physics.
    New materials for ESR dosimetry2002In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 58, no 6, p. 1301-1311Article in journal (Refereed)
    Abstract [en]

    New materials for electron spin resonance (ESR) dosimetry have been investigated with the aim to find systems more sensitive than L-alanine accepted as a standard for high dose determinations. Among the investigated systems ammonium tartrate, 2-methylalanine, salts of formic acids and dithionates have been found to be more sensitive than alanine by a factor 2-10. The lower limit applies to tissue equivalent materials, while much higher sensitivities were obtained with formates and dithionates containing heavier atoms. The increased sensitivity was mainly attributed to suitable ESR properties of the room temperature stable radicals as regards spectral shape (narrow lines, little or no hyperfine structure) and microwave saturation properties (short relaxation times). The radical structures have when necessary been clarified by ENDOR spectroscopy, while the saturation properties have been screened by pulsed ESR measurements.

  • 10.
    Lund, Eva
    et al.
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiation Physics . Linköping University, Department of Medicine and Care, Radiation Physics.
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Health Sciences, Radiation Physics . Linköping University, Department of Medicine and Care, Radiation Physics.
    Danilczuk, M
    Sastry, MD
    Lund, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    Compounds of Li-6 and natural Li for EPR dosimetry in photon/neutron mixed radiation fields2004In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 60, no 6, p. 1319-1326Article in journal (Refereed)
    Abstract [en]

    Formates and dithionates of Li-6, enriched and Li-7 in natural composition of Li offer a possibility to measure the absorbed dose from photons and thermal neutrons in a mixed radiation field for instance at a boron neutron capture therapy (BNCT) facility. Tests with formates and dithionates of enriched 6Li and lithium compounds with natural composition have been performed at the BNCT facility at Studsvik, Sweden. Irradiations have been performed at 3 cm depth in a Perspex phantom in a fluence rate of thermal neutrons 1.8 x 10(9) n cm(-2) s(-1). The compounds were also irradiated in a pure X-ray field from a 4 MV linear accelerator at 5 cm depth in a phantom with accurately determined absorbed doses. The signal intensity and shape was investigated within 3 h after the irradiation. A single line spectrum attributed to the CO2- radical was observed after irradiation of lithium formate. An increase in line width occurring after neutron irradiation in comparison with photon irradiation of the Li-6 sample was attributed to dipolar broadening between CO2- radicals trapped in the tracks of the alpha particles. A spectrum due to the SO3- radical anion was observed after irradiation of lithium dithionate. The signal amplitude increased using the Li-6 in place of the Li with natural composition of isotopes, in studies with low energy X-ray irradiation. Due to the decreased line width, caused by the difference in g(N) and I between the isotopes, the sensitivity with Li-6 dithionate may be enhanced by an order of magnitude compared to alanine dosimetry. After comprehensive examination of the different combinations of compounds with different amounts of Li-6 and Li-7 regarding dosimetry, radiation chemistry and EPR properties these dosimeter material might be used for dose determinations at BNCT treatments and for biomedical experiments. Interesting properties of the radical formation might be visible due to the large difference in ionization density of neutrons compared to photons. (C) 2003 Elsevier B.V. All rights reserved.

  • 11. Sastry, M
    et al.
    Gustafsson, Håkan
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radiation Physics.
    Lund, Anders
    Linköping University, Department of Physics, Chemistry and Biology.
    Lund, Eva
    Linköping University, Faculty of Health Sciences. Linköping University, Department of Medicine and Care, Radiation Physics. Östergötlands Läns Landsting, Centre of Surgery and Oncology, Department of Radiation Physics.
    51V(n,β)52Cr reaction for neutron dosimetry: Development and assessment of a spectrophotometric method for determination of Cr in vanadium at sub ppm level2004In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 60, no 10, p. 2363-2367Article in journal (Refereed)
    Abstract [en]

    With a view to monitoring the changes in coloration caused by the nuclear reaction 51V(n,β)52Cr in solution of vanadyl sulphate and using it for neutron dosimetry, electronic absorption spectra of vanadyl sulphate solutions were investigated at different concentrations of chromate impurity in micromolar range. It was observed that the presence of chromate enhances the absorptivity over a wide wavelength range serving essentially as a colouring agent for vanadium matrix, presumably due to charge transfer process. The absorbance at 380nm varied linearly over a wide concentration range. The limit of detection of chromate obtained is shown to be adequate for detecting neutron-induced chemical transmutation of vanadium to chromium under standard reactor conditions, when used with long path length cells. It was observed that the absorbance does not change on electron irradiation, suggesting that radiolytic effects due to beta decay, if any, do not interfere in the measurement of neutron-induced changes. In addition to its potential for neutron dosimetry, this is the first report of a simple and direct method of estimation of Cr in vanadium matrix at sub ppm level.

  • 12.
    Sharma, L Ajitkumar
    et al.
    Manipur University.
    Singh, O Ibopishak
    Manipur University.
    Singh, A K Manihar
    Manipur University.
    Singh, R K Hemakumar
    Manipur University.
    Kadam, Ramakant M
    Bhabha Atomic Research Centre.
    Bhide, Madhusudan K
    Bhabha Atomic Research Centre.
    Dhobale, Ashok R
    Bhabha Atomic Research Centre.
    Sastry, Medury D
    Linköping University, Department of Physics, Chemistry and Biology. Linköping University, The Institute of Technology.
    Molecular magnetic properties of two-copper(II) containing complexes [Cu(II) (1-phenylamidino-O-n-butylurea) en (H2O)(2)(2+) and [Cu(II) sulphato-mono (1-phenylamidino-O-methylurea)](2) - An EPR study2004In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 60, no 7, p. 1593-1600Article in journal (Refereed)
    Abstract [en]

    Electron paramagnetic resonance (EPR) investigations were conducted on [Cu(II) (1-phenylamidino-O-n-butylurea) en (H2O)12 21 (1) and [Cu(II) sulphato-mono (1-phenylamidino-O-methylurea)](2) (2) respectively, in the temperature range 300-77 K. Fine structure characteristics of S = 1 system, was observed in both complexes with zero field splitting of 0.0525 and 0.0225 cm(-1), respectively, suggesting the formation of dimeric complexes. The presence of the half-field signal (DeltaM(s)= +/-2), in the complex 1, further confirmed the formation of dimer. The temperature dependence of EPR signal intensity has given evidence for the ferromagnetic (FM) coupling between the two Cu2+ ions. The isotropic exchange interaction constants J, were evaluated from this and were found out to be similar to57 and similar to27 cm(-1), respectively, for the complexes I and 2. The photoacoustic spectra of these complexes had shown a band around 26,400 cm(-1) characteristic of metal-metal bonding giving an independent support for the existence of dimeric Cu2+ species. The high magnetic moment values at room temperature for complex I (2.68mu(B)) and complex 2 (2.00mu(B)), obtained from the magnetic susceptibility measurements, support the formation of ferromagnetically coupled Cu2+ dimers.

  • 13.
    Wang, Hui
    et al.
    Wannan Med Coll, Peoples R China.
    Fang, Bin
    Anhui Univ, Peoples R China.
    Kong, Lin
    Anhui Univ, Peoples R China.
    Li, Xiangzi
    Wannan Med Coll, Peoples R China.
    Feng, Zhijun
    Wannan Med Coll, Peoples R China.
    Wu, Yunjun
    Wannan Med Coll, Peoples R China.
    Uvdal, Kajsa
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A novel Schiff base derivative: Synthesis, two-photon absorption properties and application for bioimaging2018In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 198, p. 304-308Article in journal (Refereed)
    Abstract [en]

    A novel donor-pi-acceptor-pi-donor type (D-pi-A-pi-D) Schiff base derivative (L) has been designed and synthesized. The structure of L is confirmed by single-crystal X-ray diffraction analysis as well. The photophysical properties of compound L were comprehensively investigated by using both experimental and theoretical methods. The results indicate that L exhibits large Stokes shift and moderate two-photon action (2PA) cross-section in the near infrared (NIR) region. Furthermore, the confocal microscopy imaging study demonstrates that compound L could penetrate into cells and target the cellular mitochondria compartment. Due to its low cytotoxicity, compound L provides a promising tool for directly lighting up the mitochondria compartment in living HepG2 cells. (C) 2018 Elsevier B.V. All rights reserved.

  • 14.
    Wang, Hui
    et al.
    Wannan Med Coll, Peoples R China.
    Fang, Bin
    Anhui Univ, Peoples R China.
    Xiao, Lufei
    Chuzhou Vocat and Tech Coll, Peoples R China.
    Li, Di
    Wannan Med Coll, Peoples R China.
    Zhou, Le
    Wannan Med Coll, Peoples R China.
    Kong, Lin
    Anhui Univ, Peoples R China.
    Yu, Yan
    Wannan Med Coll, Peoples R China.
    Li, Xiangzi
    Wannan Med Coll, Peoples R China.
    Wu, Yunjun
    Wannan Med Coll, Peoples R China.
    Hu, Zhang-Jun
    Linköping University, Department of Physics, Chemistry and Biology, Molecular Surface Physics and Nano Science. Linköping University, Faculty of Science & Engineering.
    A water-soluble "turn-on" fluorescent probe for specifically imaging mitochondria viscosity in living cells2018In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 203, p. 127-131Article in journal (Refereed)
    Abstract [en]

    Rational design of water-soluble probes for mitochondrial viscosity in practical biological applications remains a challenge. Herein, we described a novel hydro soluble benzothiazole salt derivative MitoSN, which exhibits specifically response and singular sensitivity to the mitochondria viscosity in living Hela cells. MitoSN displays an excellent fluorescence enhancement (ca. 35-fold) with the increase of the viscosity in the water-glycerol system. Moreover, confocal microscopy indicates that MitoSN is sensitive to the local viscosity and selectively stains mitochondria, the body of zebrafish as well. Importantly, MitoSN is capable to identify the viscosity difference of mitochondria in normal and nystatin treated Hela cells. The work provides a useful tool to monitor the changes of viscosity in the mitochondrial microenvironment. (C) 2018 Elsevier B.V. All rights reserved.

  • 15. Yahiro, H
    et al.
    Lund, Anders
    Linköping University, The Institute of Technology. Linköping University, Department of Physics, Chemistry and Biology, Chemical Physics .
    Shiotani, M
    Nitric oxide adsorbed on zeolites: EPR studies2004In: Spectrochimica Acta Part A - Molecular and Biomolecular Spectroscopy, ISSN 1386-1425, E-ISSN 1873-3557, Vol. 60, no 6, p. 1267-1278Article in journal (Refereed)
    Abstract [en]

    CW-EPR studies of NO adsorbed on sodium ion-exchanged zeolites were focused on the geometrical structure of NO monoradical and (NO)(2) biradical formed on zeolites. The EPR spectrum of NO monoradical adsorbed on zeolite can be characterized by the three different g-tensor components and the resolved y-component hyperfine coupling with the N-14 nucleus. Among the g-tensor components, the value of g,, is very sensitive to the local environment of zeolite and becomes a measure of the electrostatic field in zeolite. The temperature dependence of the g-tensor demonstrated the presence of two states of the Na-NO adduct, in rigid and rotational states. The EPR spectra of NO adsorbed on alkaline metal ion-exchanged zeolite and their temperature dependency are essentially the same as that on sodium ion-exchanged zeolite. On the other hand, for NO adsorbed on copper ion-exchanged zeolite it is known that the magnetic interaction between NO molecule and paramagnetic copper ion are observable in the spectra recorded at low temperature. The signals assigned to (NO)(2) biradical were detected for EPR spectrum of NO adsorbed on Na-LTA. CW-EPR spectra as well as their theoretical calculation suggested that the two NO molecules are aligned along their N-O bond axes. A new procedure for automatical EPR simulation is described which makes it possible to analyze EPR spectrum easily. In the last part of this paper, some instances when other nitrogen oxides were used as a probe molecule to characterize the zeolite structure, chemical properties of zeolites, and dynamics of small molecules were described on the basis of selected literature data reported recently. (C) 2003 Published by Elsevier B.V.

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