Bibliothek

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
Filter
  • carbon dioxide  (2)
  • Carotid body Extra-adrenal paraganglioma  (1)
  • Epithelioid angiosarcoma  (1)
Materialart
Erscheinungszeitraum
  • 1
    ISSN: 1572-879X
    Schlagwort(e): gallium oxide ; titanium oxide ; carbon dioxide ; oxidative dehydrogenation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract Ga2O3 and Ga2O3/TiO2 catalysts were found to be effective agents for the dehydrogenation of ethane to ethene in the presence of carbon dioxide at 650 °C. The activity of the Ga2O3 and Ga2O3/TiO2 catalysts in the presence of CO2 was 2–4 times higher than that without CO2. Ethene yields reached ca. 20–25% and selectivity was ca. 70–90% at 650°C in the 17% ethane and 83% CO2 feed at an SV of 9,000 ml/(g‐cat h). The presence of CO2 markedly promoted dehydrogenation of ethane over Ga2O3 and Ga2O3/TiO2 catalysts. Furthermore, the promoting effect of CO2 on the aromatization of ethane and ethene over a Ga2O3+H/ZSM‐5 catalyst was also observed above 650 °C. Aromatics yields were higher than those without CO2.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 2
    ISSN: 1572-879X
    Schlagwort(e): methane ; partial oxidation ; carbon dioxide ; reforming ; iridium ; titania ; synthesis gas
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Chemie und Pharmazie
    Notizen: Abstract A partial oxidation of methane was carried out using iridium catalysts supported on several metal oxides. The productivity of the synthesis gas from methane was strongly affected by the choice of support oxides for the catalysts. The synthesis gas production proceeded basically via a two-step reaction consisting of methane combustion to give H2O and CO2, followed by the reforming of methane from CO2 and steam. Although the combustion and the reforming of methane from steam did not depend upon the catalyst support, a large variation in the catalytic activity for the reforming of methane from CO2 was observed over Ir catalysts with different supports. The support activity order in the reforming of methane from CO2 with iridium catalysts was as follows: TiO2≧ZrO2≧Y2O3〉La2O3〉MgO≧Al2O3〉SiO2. The same order was observed in the synthesis gas production from the partial oxidation of methane.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 3
    ISSN: 1432-2307
    Schlagwort(e): IGF-II ; Carotid body Extra-adrenal paraganglioma ; Immunocytochemistry
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Summary Insulin-like-growth factor (IGF)-II-like immunoreactivity was examined in two carotid bodies and six extra-adrenal paragangliomas with use of monoclonal antibody against rat IGF-II, which crossreacts with human IGF-II. Chief cells but not sustentacular cells of the carotid body were positive at about 10% in one case and less than 1% in another case. Among four carotid body tumours, a possible vagal body tumour and one glomus jugulare tumour, all but the glomus jugulare tumour exhibited positive tumour cells irrespective of histological variations. The frequency of positive cells ranged from 20 to 60%. IGF-II like immunoreactivity, therefore, might be widely distributed in human extra-adrenal paraganglionic tissues and tumours, although its biological role in these cells remains to be elucidated.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
  • 4
    ISSN: 1432-2307
    Schlagwort(e): Angiosarcoma ; Intestinal tract ; JC70 ; Endothelin ; Epithelioid angiosarcoma
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Medizin
    Notizen: Abstract Two rare cases of intestinal epithelioid angiosarcoma arising in the sigmoid colon and small intestine are reported. The small intestinal tumours were located in the duodenum and upper jejunum. All tumours showed reddish-black protuberant masses with comparatively clear margins. Histology reveals solid and epithelioid growth of large polygonal cells, mimicking undifferentiated carcinoma. Vascular differentiation such as lumina containing red cells and intracytoplasmic vacuolization is noticed. Intense immunoreactivity toUlex europaeus agglutinin I and JC70 (CD31), and sporadic positive reaction to factor VIII related antigen were detected in one case but not in the other. However, both tumours have cells which show intense endothelin-1 immunoreactivity. Positive immunostaining occurred with low molecular weight keratins suggesting epithelial differentiation and suggested epithelioid angiosarcoma as a diagnosis, a specific entity within angiosarcoma. Because of their histological features, epithelioid angiosarcomas may be confused with undifferentiated carcinomas. Endothelin-1-like immunoreactivity seems to be a good marker for this type of angiosarcoma, even when the tumour cells lack usual marker substances for endothelial cells.
    Materialart: Digitale Medien
    Bibliothek Standort Signatur Band/Heft/Jahr Verfügbarkeit
    BibTip Andere fanden auch interessant ...
Schließen ⊗
Diese Webseite nutzt Cookies und das Analyse-Tool Matomo. Weitere Informationen finden Sie hier...