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  • 1
    Digitale Medien
    Digitale Medien
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 77 (1995), S. 1938-1947 
    ISSN: 1089-7550
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: The structure of polycrystalline Si (poly-Si) films, prepared by annealing amorphous Si (a-Si) films deposited using Si2H6, has been investigated by x-ray diffraction (XRD), Raman scattering, transmission electron microscopy (TEM), and electron spin resonance, as functions of deposition conditions, such as deposition temperature Td (450–580 °C) of the a-Si and annealing time under a fixed temperature of 600 °C. A dominant texture of the poly-Si films changed from a 〈100〉 texture for Td below 530 °C to a 〈111〉 for Td above 530 °C, independent of the deposition rate of the a-Si films and of the film thickness. Although the XRD grain size was independent of Td, the TEM grain size increased from 1.0 to 2.5 μm with decreasing Td. It is suggested that the increase in this TEM size is caused by enhanced lateral growth of 〈100〉 grains due to the presence of strain. The spin density Ns and the factor g were found to first increase with the annealing time, and rapidly decreased after the films were crystallized. It is also found that the value of g for the poly-Si films decreased from 2.0051 to 2.0048 with decreasing Td. Furthermore, effects of post-hydrogenation on the poly-Si films with different textures were investigated, and a structural change of the boundary regions in the poly-Si films is discussed in connection with a change in the dominant texture, through the corresponding change in g. © 1995 American Institute of Physics.
    Materialart: Digitale Medien
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  • 2
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: Rats fed either a safflower oil (α-linolenate-deficient) or a perilla oil (α-linolenate-sufficient) diet through two generations (F1) showed significant differences in the brightness-discrimination learning task. In this task, correct responses were lever-pressing responses, which were reinforced with dietary pellets, and incorrect responses were those with no reinforcement. The inferior learning performance in the safflower oil group was caused mainly by the inferior ability to rectify the incorrect responses through the learning sessions. In the safflower oil group after the learning task, the average densities of synaptic vesicles in the terminals of the hippocampus CA1 region were decreased by nearly 30% as compared with those in the perilla oil group, and it is notable that this difference was not detected without the learning task. These results suggest that dietary oil-induced morphological changes in synapses in the hippocampus of rats are related to the differential learning performance and that the turnover rate of synaptic vesicles in the hippocampus may be an important factor affecting learning performance.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1471-4159
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Abstract: Biochemical characteristics of brain microsomal membranes were examined before and after the brightness-discrimination learning tasks in rats that were fed either safflower oil (α-linolenate-deficient) or perilla oil (α-linolenate-sufficient) diets. We detected small changes in the chain elongation system for polyunsaturated fatty acids in microsomes, whereas no significant difference was detected in the inositol trisphosphate-induced calcium release and ATP-induced calcium uptake profiles of microsomes between the two dietary groups. The calcium ion-induced aggregation rate of microsomes was determined in both groups. We found that the aggregation rate of microsomes in the safflower oil group was significantly greater than that in the perilla oil group. The difference in susceptibility of microsomal membrane phospholipids to phospholipase A2 between the groups was obvious, and the amount of released fatty acids by phospholipase A2 from the perilla oil group microsomes was nearly half of that from the safflower oil group microsomes after the learning task. Susceptibility of sialic acids on the brain microsomal membranes to exogenous sialidase was different only after the learning task in the safflower and perilla oil groups. These results suggest that the biochemical characteristics of membrane surfaces of brain microsomes are affected significantly by the learning task itself in a dietary oil-dependent manner.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: To determine the involvement of proteinases with hydrolytic activity towards extracellular matrix and basement membrane, in invasion and metastasis of tumour cells, the expression of cathepsin D, an aspartic proteinase, and cathepsin B, a cysteine proteinase, was studied. Formalin-fixed paraffinembedded specimens from 13 patients who had squamous cell carcinomas (SCC) with local recurrence, skin and/or lymph node metastasis were examined. Cathepsin D stained intensely as a granular pattern (mature enzyme) in tumour cells of 69% of primary lesions and all the secondary lesions of the patients with SCC. Cathepsin B stained more intensely in SCC cells of all of the primary and secondary lesions than in normal epidermis: staining patterns were almost diffuse (procathepsin B). Granular and diffuse patterns (mature enzyme of cathepsin D and procathepsin B, respectively) appeared in the outer and inner parts of tumour islands, respectively. The presence of the active mature form of cathepsin D and procathepsin B in metastatic skin lesions of SCC was confirmed by Western blotting analysis. The presence and localization of the active mature form of cathepsin D suggests that activated cathepsin D may be involved in the invasion and metastasis of SCC.
    Materialart: Digitale Medien
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  • 5
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Several studies have been reported on the effects of various therapeutic agents in enhancing or suppressing the carcinogenic activity of N-methyl-N′-nitro-N-nitrosoguanidine (MNNG). However, it is still unknown whether a mucosal protective agent could suppress its carcinogenic activity.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:Twenty-five Wistar male rats were divided into four groups: group 1, MNNG alone; group 2, MNNG + tetraprenylacetone; group 3, control; group 4, tetraprenylacetone alone. MNNG 100 mg/mL was freely given to groups 1 and 2, and tetraprenylacetone (200 mg/kg intraperitoneal) was additionally administered every other day to the rats in groups 2 and 4. The animals were sacrificed at 10 weeks and the gastric mucosa examined.〈section xml:id="abs1-3"〉〈title type="main"〉Results:Atrophic changes were observed in the antrum after 8 weeks of oral administration of MNNG. Furthermore, using immunohistological analysis with 5-bromo-2′-deoxyuridine (BrdU), the proliferative zone was found to be enlarged and shifted upward, although the BrdU labelling index of the proliferative zone was unaltered. Intraperitoneal administration of tetraprenylacetone every other day suppressed the MNNG-induced atrophic change and the alterations proliferative markers. Tetraprenylacetone alone did not have an effect either on morphological or proliferative markers.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusion:These observations suggest that gastric mucosal defensive factors may play critical roles in suppressing atrophic change inducing carcinogenesis by an exogenic carcinogen.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1365-2044
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Both the cuffed oropharyngeal airway and the laryngeal mask airway share a similar property of being less stimulating to the upper airway than the tracheal tube. This study was conducted to compare sevoflurane concentrations required for insertion of the cuffed oropharyngeal airway and the laryngeal mask airway in elderly and young adult patients. Forty-one elderly (65–90 years) and 34 young adult (18–50 years) patients, scheduled for elective surgery during spontaneous breathing anaesthesia were randomly assigned to either the cuffed oropharyngeal airway or the laryngeal mask airway group. After a predetermined end-tidal concentration of sevoflurane had been established and maintained for at least 20 min, insertion of the device was attempted without neuromuscular relaxants or other adjuvants. Each concentration at which insertion of the device was attempted was predetermined by modification of Dixon's up-and-down method with 0.5% as the step size. Sevoflurane MACCOPA [mean 1.17 (SD 0.38)%, 0.77–1.56% (95% CI)] was significantly less than MACLMA [2.00 (0.52)%, 1.45–2.55%, p 〈 0.05] for elderly patients. Similarly, sevoflurane MACCOPA [1.33 (0.38)%, 0.94–1.73%] was significantly less than MACLMA [2.00 (0.42)%, 1.56–2.44%, p 〈 0.05] for young adult patients. There were no significant differences in either MACCOPA or MACLMA between the elderly and the young adult patients. We conclude that the insertion of the cuffed oropharyngeal airway can be accomplished at a lower sevoflurane concentration, and hence, is less stimulating to the upper airway than that of the laryngeal mask airway.
    Materialart: Digitale Medien
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  • 7
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Nephrology 4 (1998), S. 0 
    ISSN: 1440-1797
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
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  • 8
    Digitale Medien
    Digitale Medien
    Melbourne, Australia : Blackwell Science Asia Pty. Ltd.
    Nephrology 5 (1999), S. 0 
    ISSN: 1440-1797
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Materialart: Digitale Medien
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  • 9
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    Clinical and experimental dermatology 22 (1997), S. 0 
    ISSN: 1365-2230
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: We report a 52-year-old female with trichogenic trichoblastoma arising on the supraclavicular fossa. Clinical and histological examinations revealed a thumbnail sized, elastic, hard, subcutaneous nodule which consisted of keratinous cysts and epithelial cords of basaloid cells with locally follicular differentiation. Based on histological observations, a diagnosis of trichogenic trichoblastoma was made. An immunohistochemical study using a panel of monoclonal antibodies against cytokeratins was performed to investigate the nature and differentiation of this tumour. The most characteristic findings of the immunohistochemistry were CK 8 and 19 expression in the epithelial cords and the outer cells of the cystic structures. These immunoreactivities were similar to those of the outermost layer of the outer root sheath between the lower permanent portion and the upper transient portion, and immunostaining with the other antibodies confirmed this similarity. We can speculate that trichogenic trichoblastoma differentiates mainly toward the outermost layer of the outer root sheath between the lower permanent portion and the upper transient portion, and then into follicular structures.
    Materialart: Digitale Medien
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  • 10
    Digitale Medien
    Digitale Medien
    Oxford, UK : Blackwell Publishing Ltd
    British journal of dermatology 133 (1995), S. 0 
    ISSN: 1365-2133
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: We report a 49-year-old woman with an eccrine syringofibroadenoma. An asymptomatic nodule appeared on the right heel, and subsequently enlarged gradually. Histological examination revealed anastomosing strands of pale epithelial cells, with occasional duct formation and mucinous fibrovascular stroma. There were two types of strands: thick and thin. Immunohistochemical study, using a panel of monoclonal antikeratin antibodies, revealed that the immunoreactivity differed between the two types of strands. The thick strands showed a staining pattern similar to the uppermost portion of the intradermal duct, and the thin strands showed a pattern similar to the other portion of the duct. This observation suggests that the thick and thin strands differentiate towards the uppermost portion and the remainder of the duct, respectively.
    Materialart: Digitale Medien
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