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  • Articles: DFG German National Licenses  (35)
  • 2000-2004  (13)
  • 1985-1989  (22)
  • 1
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 83 (1985), S. 280-287 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Limiting molar conductances of the K+ and Cl− ions in heavy and light water have been determined at 25 °C as a function of pressure up to 2 kbar from the measured conductances and transference numbers of KCl. The residual friction coefficients (Δζ) are obtained for the cation and the anion in D2O and H2O by using the determined limiting conductance and the bulk viscosity of solvent and compared with the corresponding values predicted by applying the Hubbard–Onsager (HO) dielectric friction theory at various pressures below 1 kbar. At atmospheric and high pressures Δζ of the K+ ion in D2O is larger than that in H2O just as predicted by the HO theory, but Δζ of the Cl− ion in D2O is smaller than that in H2O on the contrary to the theoretical prediction. The reverse solvent isotope effect on Δζ(Cl−) suggests that a microscopic viscosity in the vicinity of the relatively large ion is smaller than the bulk viscosity used in the continuum theory.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 86 (1987), S. 4678-4683 
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: Limiting molar conductances of the K+ and Cl− ions in heavy and light water have been determined at 5 °C as a function of pressure up to 1500 kgf cm−2 (1 kgf cm−2=0.9807×105 Pa) from the measured conductances and transference numbers of KCl. The residual friction coefficients (Δζ) are obtained for the cation and anion in D2O and H2O by using the determined limiting conductance and the bulk viscosity of solvent, and they are compared with the corresponding values predicted by applying the Hubbard–Onsager (HO) dielectric friction theory at various pressures below 1000 kgf cm−2. At atmospheric and high pressures, the solvent isotope and temperature effects on Δζ observed for the K+ ion are qualitatively in agreement with the theoretical prediction. However, the slightly positive pressure coefficients of Δζ(K+) are obtained in both solvents at 5 °C contrary to the theoretical prediction. Furthermore, Δζ(K+) in D2O at 5 °C is smaller than the theoretical one. These results suggest that another mechanism such as the passing through cavities one plays a more important role in ion migration of the K+ ion at lower temperatures and in D2O. On the other hand, the reverse solvent isotope and temperature effects on Δζ(Cl−), and the negative values of Δζ(Cl−) are found. These anomalies cannot be explained by the continuum theory.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 54 (1989), S. 2400-2401 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A new visible chemical laser analogous to excimer lasers in lasing principle has been studied. Laser oscillation has been observed in the red spectral range. To our knowledge this is the first demonstration of chemical laser oscillation in the visible spectral range.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 55 (1989), S. 2707-2708 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: New emission spectra have been observed from chemically produced excited oxygen. Evidence that the observed visible emission is due to oxygen dimer transitions is presented. Experimental results suggest that the observed oxygen dimer is stable O4 molecule rather than the usually observed Van der Waals-type dimolecular complex. The present system is discussed from the viewpoint of a new laser operating in the visible. The possibility of a similar oxygen-dimer laser operating in the near infrared is also discussed.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 14 (2000), S. 0 
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background: Sofalcone has been reported to exert anti-ulcer and gastroprotective actions, but its exact mechanism of action remains unknown. In our laboratory, we found that indomethacin-induced gastric ulcers become worse when associated with Helicobacter pylori infection. Methods: We employed the H. pylori-infected gnotobiotic murine model to examine the effect of sofalcone on indomethacin-induced gastric ulcers in the presence of H. pylori infection. In vitro experiments were also done to evaluate the effects of sofalcone on H. pylori growth, adherence of H. pylori to the MKN45 cells (a human gastric epithelial cell line), and these cells' IL-8 production in the presence of H. pylori. Results: We found that sofalcone produced a significant improvement in ulcer size as well as a substantial reduction in the number of H. pylori colonies in H. pylori-infected gnotobiotic mice. In vitro sofalcone has a significant bacteriocidal effect against H. pylori and can also significantly prevent adherence of this bacterium to MKN45 cells, thus remarkably reducing IL-8 production of these cells in response to stimulation by H. pylori. Conclusion: Our results suggest that sofalcone can improve ulcer healing by the mechanisms mentioned above.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Materials Research 18 (1988), S. 25-45 
    ISSN: 0084-6600
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Previous studies have shown that rat peritoneal mast cells and mast cell model rat basophilic leukaemia (RBL-2H3) cells generate intracellular reactive oxygen species (ROS) in response to antigen challenge. However, the physiological significance of the burst of ROS is poorly understood.Objective The present study was undertaken to investigate the role of superoxide anion in mediator release in rat and human cell systems.Methods RBL-2H3 cells were directly stimulated with anti-rat FcεRI α-subunit monoclonal antibody (mAb). For the analysis of human cell system, leucocytes were isolated by dextran sedimentation from healthy volunteers or from patients, and challenged either with anti-human FcεRI mAb or with the relevant antigens. Superoxide generation was determined by chemiluminescence-based methods. The releases of histamine and leukotrienes (LT)s were determined by enzyme-linked immunosorben assay (ELISA).Results Cross-linking of FcεRI on RBL-2H3 cells or on human leucocytes from healthy donors by the anti-FcεRI mAb resulted in a rapid generation of superoxide anion, as determined by chemiluminescence using superoxide-specific probes. Similarly, leucocytes from patients generated superoxide anion in response to the challenge with the relevant allergen but not with the irrelevant allergen. Furthermore, diphenyleneiodonium (DPI), a well-known inhibitor of flavoenzymes suppressed the superoxide generation and the release of histamine and LTC4 induced by the anti-FcεRI mAb or by allergen in parallel.Conclusion These results indicate that both RBL-2H3 cells and human basophils generate superoxide anion upon FcεRI cross-linking either by antibody or by allergen challenge and that blockade of the generation prevents the release of allergic mediators. The findings strongly support the role of superoxide generation in the activation of mast cells and basophils under both physiological and pathological conditions. The findings suggest that drugs regulating the superoxide generation have potential therapeutic use for allergic disorders.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1365-2222
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Background Influenza virus (IV) infection causes airway inflammation; however, it has not been determined whether IV infection could catabolize arachidonic acid cascade in airway epithelial cells. In addition, the responsible intracellular signalling molecules that catabolize arachidonic acid cascade have not been determined.Objective In the present study, to clarify these issues, we examined the cyclooxygenase (COX) expression, cytosolic phospholipase A2 (cPLA2) phosphorylation and prostaglandin E2 (PGE2) release in human bronchial epithelial cells (BEC) upon IV infection, and the role of mitogen-activated protein kinase (MAPK) including extracellular signal-regulated kinase (ERK), p38 MAPK and c-Jun-NH2-terminal kinase (JNK) in catabolizing arachidonic acid cascade in BEC.Methods COX-2 expression, phosphorylation of cPLA2 and phosphorylation of ERK, JNK and p38 MAPK were determined by Western blot. The concentrations of PGE2 were determined by ELISA. PD 98059 as a specific inhibitor of MAPK kinase-1 (MEK-1), an up-stream kinase of ERK, SB 203580 as a specific inhibitor of p38 MAPK and CEP-11004 as a specific inhibitor of JNK cascade were used to investigate the role of ERK, p38 MAPK and JNK in catabolizing arachidonic acid cascade in BEC.Results The results showed that (1) IV infection increases COX-2 expression, cPLA2 phosphorylation and PGE2 release, (2) ERK, p38 MAPK and JNK were phosphorylated, (3) CEP-11004 and PD 98059 predominantly attenuated COX-2 expression and cPLA2 phosphorylation, respectively, (4) SB 203580 did not remarkably affect COX-2 expression and cPLA2 phosphorylation, and (5) each inhibitor dose-dependently attenuated PGE2 release by various extents.Conclusion These results indicate that IV infection activates three distinct MAPKs, ERK, p38 MAPK and JNK, to participate to various extents in the induction of PGE2 synthesis from arachidonic acid in BEC.
    Type of Medium: Electronic Resource
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  • 9
    ISSN: 1365-2133
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Summary Background  Annular erythema (AE) in Sjögren's syndrome (SS) usually develops on areas of sun-exposed skin and is exacerbated during summer. Objectives  To evaluate photosensitivity in SS and to investigate the involvement of ultraviolet (UV) radiation in the development of AE in SS. Methods  Phototesting with UVA and UVB was performed on 14 SS patients, including 10 with primary SS. Clinical and histological features as well as expression of inducible nitric oxide synthase (iNOS) in the evoked skin lesions were compared with those of lupus erythematosus (LE). Eleven SS patients had a history of photosensitive AE ( n  = 4), papules ( n  = 3) or other types ( n  = 4) of lesions on their sun-exposed skin that were induced or aggravated by sunlight exposure. Results  Phototesting induced a prolonged erythematous response ( n  = 8), infiltrated erythema (IE) ( n  = 4) and/or papules ( n  = 3) in 11 of 14 SS patients, including one with primary SS without a history of photosensitivity. Histologically, the induced IE and papules showed coat-sleeve-like or sparse perivascular infiltration of lymphocytes similar to that in primary skin lesions of AE in SS. No epidermal changes characteristic for LE were found except for partial and mild liquefaction degeneration in three cases. In contrast, two cases were indistinguishable from the papular type of polymorphic light eruption in several aspects, including their primary skin lesions and early response to a photoprovocation test. Immunohistochemistry revealed diffuse expression of iNOS throughout the epidermis, which is characteristic for LE, in the three SS patients with minimal liquefaction degeneration, while the remaining seven SS patients examined exhibited no iNOS staining or a normal expression pattern. Conclusions  Our results indicate that photosensitivity exists in certain primary SS patients, and that UV is critical to the development of AE in SS, probably through a pathological mechanism distinct from that in LE.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Publishing Ltd
    Journal of fish biology 58 (2001), S. 0 
    ISSN: 1095-8649
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Biology
    Notes: The onset of schooling behaviour and brain growth in larval yellowtail Seriola quinqueradiata larvae fed on Artemia enriched with oleic acid (OA), eicosapentaenoic acid (EPA) or docosahexaenoic acid (DHA) for 10 days was investigated. Larvae from the DHA groups schooled with parallel orientation while those of the EPA groups showed only aggregation. Larvae of the OA groups were dispersed. DHA and EPA groups showed significantly smaller nearest neighbour distance compared with OA groups, and DHA groups showed significantly smaller values of nearest neighbour angle compared with the other groups. The relative volume of the tectum opticus (TO) of the DHA group was significantly larger in two experiments and also the relative volume of the cerebellum (CE) of that group was significantly larger in one experiment. Dietary DHA is probably critically important for the development of the brain, particularly TO, during the larval stages, and that development of TO may be the key factor of the ontogeny of schooling behaviour.
    Type of Medium: Electronic Resource
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