Bibliothek

X
feed icon rss

Ihre E-Mail wurde erfolgreich gesendet. Bitte prüfen Sie Ihren Maileingang.

Leider ist ein Fehler beim E-Mail-Versand aufgetreten. Bitte versuchen Sie es erneut.

Vorgang fortführen?

Exportieren
  • 1
    Digitale Medien
    Digitale Medien
    GaAlAs laser diodes with metalorganic chemical vapor deposition grown ZnSe layer for injection blocking and optical confinement (1987)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 51 (1987), S. 877-879 
    Details
    ISSN: 1077-3118
    Quelle: AIP Digital Archive
    Thema: Physik
    Notizen: A transverse mode stabilized GaAlAs laser diode which includes a ZnSe layer for the waveguide has been developed. The double heterostructure of the GaAlAs laser is formed by low-pressure metalorganic chemical vapor deposition (MOCVD), and a ZnSe layer is grown by adduct-source MOCVD in order to block the injection current and change the real refractive index in the lateral direction. The fundamental transverse mode oscillation of more than 15 mW is obtained with a low threshold current of 28 mA and a high quantum efficiency of 76%. An output power as high as 25 mW is achieved.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.98841
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 2
    Digitale Medien
    Digitale Medien
    Evaluation of soft x-ray average recombination coefficient and average charge for metallic impurities in beam-heated plasmas (1986)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 57 (1986), S. 2148-2150 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: The soft x-ray continuum radiation in tokamak fusion test reactor (TFTR) low-density neutral-beam discharges can be much lower than its theoretical value obtained by assuming a corona equilibrium. This reduced continuum radiation is caused by an ionization equilibrium shift toward lower states, which strongly changes the value of the average recombination coefficient of metallic impurities γ¯, even for only slight changes in the average charge Z¯. The primary agent for this shift is the charge exchange between the highly ionized impurity ions and the neutral hydrogen, rather than impurity transport, because the central density of the neutral hydrogen is strongly enhanced at lower plasma densities with intense beam injection. In the extreme case of low-density, high neutral-beam power TFTR operation (energetic ion mode) the reduction in γ¯ can be as much as one-half to two-thirds. We calculate the parametric dependence of γ¯ and Z¯ for Ti, Cr, Fe, and Ni impurities on neutral density (equivalent to beam power), electron temperature, and electron density. These values are obtained by using either a one-dimensional impurity transport code or a zero-dimensional code with a finite particle confinement time. As an example, we show the variation of γ¯ and Z¯ in different TFTR discharges.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1138712
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 3
    Digitale Medien
    Digitale Medien
    Effective Kα x-ray excitation rates for plasma impurity measurements (1986)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 57 (1986), S. 2151-2153 
    Details
    ISSN: 1089-7623
    Quelle: AIP Digital Archive
    Thema: Physik , Elektrotechnik, Elektronik, Nachrichtentechnik
    Notizen: Metal impurity concentrations are measured by the pulse-height-analyzer (PHA) diagnostic from Kα x-ray peak intensities by use of an averaged excitation rate 〈σv〉. Low-Z impurity concentrations are inferred from the continuum enhancement (relative to a pure plasma) minus the enhancement due to metals. Since the PHA does not resolve lines from different charge states, 〈σv〉 is a weighted sum of rates; coronal equilibrium is usually assumed. The 〈σv〉 used earlier omitted the intercombination and forbidden lines from the dominant heliumlike state. The result was an overestimate of metals and an underestimate of low-Z impurities in cases where metals were significant. Improved values of 〈σv〉 using recent calculations for H-, He-, and Li-like Fe range from 10% to 50% larger than the earlier rates and yield metal concentrations in better agreement with those from vacuum ultraviolet (VUV) spectroscopy.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1063/1.1138713
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 4
    Digitale Medien
    Digitale Medien
    c-erbB-2 and c-Met expression relates to cholangiocarcinogenesis and progression of intrahepatic cholangiocarcinoma (2002)
    Oxford UK : Blackwell Science Ltd.
    Histopathology 40 (2002), S. 0 
    Details
    ISSN: 1365-2559
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: c-erbB-2 and c-Met expression relates to cholangiocarcinogenesis and progression of intrahepatic cholangiocarcinoma Aims: The c-erbB-2 and c-Met proto-oncogenes are important for tumour invasiveness and metastasis in many types of malignant tumours. Previous studies have indicated that these proteins are associated with carcinogenesis in intrahepatic cholangiocarcinoma. In this study, we examined c-erbB-2 and c-Met expression by immunohistochemistry in hepatolithiasis, intrahepatic cholangiocarcinoma and metastatic lymph node, in order to clarify whether these proteins play a role in carcinogenesis and tumour metastasis in intrahepatic cholangiocarcinoma. Methods and results: In hepatolithiasis, the staining for c-erbB-2 was positive in 14 of the 23 (61%) cases, while staining for c-Met was positive in eight of the 23 (35%) cases. In intrahepatic cholangiocarcinoma, staining for c-erbB-2 was positive in 45 of the 81 (55%) cases, while staining for c-Met was positive in 28 (35%) cases. The positivity of c-Met staining in intrahepatic cholangiocarcinoma was significantly higher in the differentiated type of cholangiocarcinoma than in the undifferentiated type. In addition, c-Met-positive staining had an inverted correlation with tumour size, the presence of perineural invasion and the presence of lymph node metastasis. c-Met staining had a significantly higher positivity in cases at an early stage of intrahepatic cholangiocarcinoma. In contrast, the positivity of c-erbB-2 staining in intrahepatic cholangiocarcinoma was significantly higher in cases with lymph node metastasis than in cases without. In metastatic lymph nodes, the staining for c-erbB-2 was positive in 20 of the 25 (80%) cases, while staining for c-Met was positive in six of the 25 (24%) cases. There was no difference in survival between c-erbB-2-positive and negative patients. However, the patients with c-Met-positive tumours had a significantly longer survival than those with c-Met-negative tumours in the medium survival term. The multivariate analysis showed the presence of lymph node metastasis, lymphatic permeation and histological differentiation to be independent prognostic factors. Conclusion: These results indicate that increased c-Met expression participates in cholangiocarcinogenesis and in the early developmental stages of intrahepatic cholangiocarcinoma, while increased c-erbB-2 expression contributes to the development of cholangiocarcinogenesis into an advanced stage associated with tumour metastasis.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2559.2002.00353.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 5
    Digitale Medien
    Digitale Medien
    Comparison between in vivo and in vitro chemokine production in Helicobacter pylori infection (2000)
    Oxford, UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 14 (2000), S. 0 
    Details
    ISSN: 1365-2036
    Quelle: Blackwell Publishing Journal Backfiles 1879-2005
    Thema: Medizin
    Notizen: Background: Enhanced gastric mucosal chemokine activity has been demonstrated in patients with Helicobacter pylori infection. However, little is known about the mechanisms involved in this phenomenon. Aim: To examine whether in vivo chemokine activity is similar to in vitro response of gastric epithelial cells infected by H. pylori. Patients and Methods: Antral biopsy specimens were obtained from patients with H. pylori infection for organ culture, isolation of H. pylori and histological examination. Results: In organ cultures of mucosal tissues, the levels of interleukin-8 and growth-related gene product α were elevated in patients with peptic ulcer disease compared with those with erosive gastritis or endoscopically normal mucosa. However, there were no significant differences in in vitro cultures of MKN45 or KATO III cells that were infected with H. pylori isolated from these same patients. These in vivo and in vitroα-chemokine levels showed no significant association with the presence of cagA gene and CagA protein, ureB genotype, or binding capacity to MKN45 or KATO III cells in individual H. pylori isolates. In contrast, in vivo mucosal α-chemokine activity correlated with H. pylori colonization density. Conclusion: Mucosal chemokine profiles and inflammatory responses in H. pylori infection may be associated more closely with host factors, including those determining bacterial adhesiveness, than with differences in H. pylori strains.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1046/j.1365-2036.2000.014s1205.x
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 6
    Digitale Medien
    Digitale Medien
    Ultrastructural alterations on chloride cells of the yellowtail Seriola quinqueradiata, following exposure to the red tide species Chattonella antiqua (1985)
    Springer
    Marine biology 88 (1985), S. 101-108 
    Details
    ISSN: 1432-1793
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract By means of scanning and transmission electron microscopy, the influence of the red tide species Chattonella antiqua was examined with respect to the surface ultrastructures of chloride cells of the yellowtail Seriola quinqueradiata. Conspicuous ultrastructural alterations occurred on the apical surface of these cells. The majority of chloride cells in the control gills showed an apical surface with numerous cellular extensions, while more than half the chloride cells affected by red tide organisms exhibited an apical surface with fewer and smaller extensions, a wrinkled apical surface, or a protruded apical surface. These ultrastructural alterations of chloride cell surface may be due to the partial disturbance of salinity by C. antiqua, and reflect the changes of the ion-transport function in yellowtail gills exposed to red tide water.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00393048
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 7
    Digitale Medien
    Digitale Medien
    Asynchronization of local population dynamics and persistence of a metapopulation: a lesson from an endangered composite plant, Aster kantoensis (2000)
    Springer
    Population ecology 42 (2000), S. 63-72 
    Details
    ISSN: 1437-5613
    Schlagwort(e): Key words Habitat fragmentation ; Spatially structured model ; Extinction risk assessment ; CV2 ; Population viability analysis ; Conservation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Fragmentation of a large habitat makes local populations less linked to others, and a whole population structure changes to a metapopulation. The smaller a local population is, the more strengthened extinction factors become. Then, frequent extinctions of local populations threaten persistence of the metapopulation unless recolonizations occur rapidly enough after local extinctions. Spatially structured models have been more widely used for predicting future population dynamics and for assessing the extinction risk of a metapopulation. In this article, we first review such spatially structured models that have been applied to conservation biology, focusing on effects of asynchronization among local population dynamics on persistence of the whole metapopulation. Second, we introduce our ongoing project on extinction risk assessment of an endangered composite biennial plant, Aster kantoensis, in the riverside habitat, based on a lattice model for describing its spatiotemporal population dynamics. The model predicted that the extinction risk of A. kantoensis depends on both the frequency of flood occurrence and the time to coverage of a local habitat by other competitively stronger perennials. Finally, we present a measure (Hassell and Pacala's CV 2) for quantifying the effect of asynchronization among local population dynamics on the persistence of a whole metapopulation in conservation ecology.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/s101440050010
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 8
    Digitale Medien
    Digitale Medien
    Pathological study on a severe sialidosis (α-neuraminidase deficiency) (1986)
    Springer
    Acta neuropathologica 71 (1986), S. 278-284 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Severe sialidosis ; α-Neuraminidase deficiency ; Neuropathology ; Congenital ascites ; Nephrosialidosis
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary A 56-day-old infant with α-neuraminidase deficiency, whose clinical features included severe edema of extremities and ascites which resembled those in severe infantile sialidosis, was autopsied. Perforation, whose pathogenesis was unclear, was found on the descending portion of the duodenum. Light and electron microscope studies showed that neurons in the cerebral and cerebellar corticies, and the thoracic spinal cord contained membrane-bound vacuoles but no membranous cytoplasmic bodies. Zebra bodies were found only in the neurons of the spinal cord. The neurons in the paraganglion and in the Auerbach's myenteric plexus were also distended with numerous membrane-bound vacuoles. Hepatocytes, endothelial cells and Kupffer cells in the liver and glomerular and tubular epithelial cells in the kidney were swollen with a number of vacuoles although the patient showed none of the clinical features of renal involvement. These pathological changes were similar to those in nephrosialidosis reported by Le Sec et al. [Arch Fr Pediatr 35:819–829 (1978)].
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00688050
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 9
    Digitale Medien
    Digitale Medien
    Golgi study on brain of macular mutant mouse as a model of Menkes kinky hair disease (1987)
    Springer
    Acta neuropathologica 72 (1987), S. 349-354 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Macular mutant mouse ; Menkes kinky hair disease ; Golgi study ; Purkinje cell ; Copper metabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary This study was undertaken to elucidate, using the Golgi method, the neuropathological change in the brain of the macular mutant mouse, whose hemizygote (Ml/y) is considered to be a model of Menkes kinky hair disease (MKHD). The hemizygote mice gradually lost weight after 10 days of age and died with emaciation and seizure around day 15. The normal littermate (+/y) was well developed. In the cerebrum, the arborization of pyramidal neurons in the layer V of the Ml/y was the same as that in the +/y on day 10. However, development of arborization in the Ml/y was delayed in comparison with that in the +/y on days 12 and 14. Purkinje cells with several somal sprouts were observed in the cerebellum in both the Ml/y and +/y on day 7. The somal sprouts in the +/y had regressed gradually by day 12, while they were still in the anterior and middle lobes of the Ml/y on day 14. Additionally, the trunks of Ml/y stem dendrites became thicker and a cactus formation was recognized on the branching portion of the dendrites on day 14. Arborization of these abnormal Purkinje cells was distinctly poor compared with that in the +/y. These results suggest that the growth of the neurons is delayed in the Ml/y and simultaneously their cytoskeletal developments are disturbed, especially in the Purkinje cells. There is a close similarity in many respects to the neuropathological change in MKHD.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00687266
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
  • 10
    Digitale Medien
    Digitale Medien
    Electron microscopic study on brain of macular mutant mouse after copper therapy (1988)
    Springer
    Acta neuropathologica 76 (1988), S. 574-580 
    Details
    ISSN: 1432-0533
    Schlagwort(e): Macular mouse ; Menkes kinky hair disease ; Copper therapy ; Mitochondrial abnormalities
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary The hemizygote of the macular mutant mice, which is clinically and neuropathologically considered to be a model of Menkes kinky hair disease (MKHD), were injected intraperitoneally four times with 10, 20, 20 and 30 μg of cupric chloride on days 4, 6, 8 and 10 after birth, respectively. Their cerebral and cerebellar cortices were chronologically examined by electron microscopy. In the cerebral cortes, only a few abnormal mitochondria with electron-lucent matrix and short peripherally located cristae were scattered in the neurons on day 14, and these had almost entirely vanished after day 21. In the cerebellar cortex, abnormal mitochondria were frequently found on day 14 in the dendrites of the Purkinje cells, whereas they were only occasionally observed in their cytoplasm. Those in the dendrites had decreased in number on day 30, and only a few of them were seen in the cerebellum after day 45. These results show that the copper therapy reduced ultrastructural abnormalities in the hemizygote of this mutant mouse.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1007/BF00689595
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
    Artikel (Nationallizenzen)
    Volltext
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...