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961.
Pteroyl polyglutamate hydrolase (folyl conjugase), which hydrolyses the dietary polyglutamyl folates into simple forms prior to absorption, has been shown to be induced in rat pancreas in response to dietary polyglutamyl folates but not by ingestion of synthetic unconjugated folates. Folate absorption, as measured by the rise in serum folate levels after ingestion, of dietary conjugated folates is impaired in pancreatectomised animals whereas absorption of synthetic simple folate is not. A severe build-up of folyl conjugase is observed in the lumen of control but not in pancreatectomised animals after dietary folate ingestion. These results taken together would suggest that dietary folates are hydrolysed to monoglutamyl forms suitable for absorption in the lumen; the hydrolysis is catalysed by a luminal folyl conjugase of pancreatic origin induced by dietary conjugated folates. 相似文献
962.
963.
Zusammenfassung Bei Agargel-Diffusionstechnik zeigenCulex-pipiens-fatigans-Eier mindestens vier deutlich voneinander unterscheidbare Präzipitationslinien, wenn sie mit homologem Antiserum reagierten. Eier vonArmigeres subalbatus, Aedes aegypti undAedes albopictus hingegen zeigten nur eine einzige Linie bei Reaktion mit dem gleichenCulex-Antiserum. 相似文献
964.
965.
S. Garattini A. Jori V. Palma L. Tessari 《Cellular and molecular life sciences : CMLS》1959,15(10):384-385
Riassunto La Metahexamide, N(3amino-4-metilbenzenesulfonil)N-cicloesilurea, possiede nel ratto e nel coniglio un effetto ipoglicemizzante più narcato rispetto alp-tolilsulfanilbutilurea (D 860). Il nuovo farmaco si dimostra più attivo del D 860 nell'accelerare la scomparsa di glucosio da parte del diaframma isolato di ratto. La Metahexamide si distribuisce rapidamente in tutti gli organi e scompare dal sangue molto lentamente. Il maggiore effetto della Metahexamide, rispetto a composti similari, viene interpretato sulla base di un lento metabolismo e in rapporto all'intenso effetto favorente la metabolizzazione del glucosio a livello periferico. 相似文献
966.
V. Erspamer T. Vitali M. Roseghini J. M. Cei 《Cellular and molecular life sciences : CMLS》1965,21(9):504-504
Riassunto Gli estratti di pelle diBufo alvarius, rospo delle regioni desertiche del Nord America, contengono, oltre alle consuete 5-idrossiindolalchilamine (5-HT, N-metil-5-HT, bufotenina) enormi quantitativi di derivati 5-metossiindolici, rappresentati soprattutto daO-metilbufotenina. Questa può giungere a costituire fino il 16% del peso delle ghiandole cutanee secche. Si insiste sulla probabile presenza di 5-idrossiindolo-O-metiltransferasi nella pelle diBufo alvarius.
Supported by a grant from the Consiglio Nazionale delle Ricerche, Roma. 相似文献
Supported by a grant from the Consiglio Nazionale delle Ricerche, Roma. 相似文献
967.
968.
N. N. Sarkar K. R. Laumas V. Hingorani 《Cellular and molecular life sciences : CMLS》1982,38(11):1345-1346
Summary The levels of available norethindrone were found to be similar in women and rabbits after s.c. administration of crystalline and amorphous, norethindrone acetate respectively, and this study indicates that the rabbit may be used as an animal model for further investigation with this contraceptive steroid. 相似文献
969.
970.
Activation of old carbon by erosion of coastal and subsea permafrost in Arctic Siberia 总被引:2,自引:0,他引:2
JE Vonk L Sánchez-García BE van Dongen V Alling D Kosmach A Charkin IP Semiletov OV Dudarev N Shakhova P Roos TI Eglinton A Andersson O Gustafsson 《Nature》2012,489(7414):137-140
The future trajectory of greenhouse gas concentrations depends on interactions between climate and the biogeosphere. Thawing of Arctic permafrost could release significant amounts of carbon into the atmosphere in this century. Ancient Ice Complex deposits outcropping along the ~7,000-kilometre-long coastline of the East Siberian Arctic Shelf (ESAS), and associated shallow subsea permafrost, are two large pools of permafrost carbon, yet their vulnerabilities towards thawing and decomposition are largely unknown. Recent Arctic warming is stronger than has been predicted by several degrees, and is particularly pronounced over the coastal ESAS region. There is thus a pressing need to improve our understanding of the links between permafrost carbon and climate in this relatively inaccessible region. Here we show that extensive release of carbon from these Ice Complex deposits dominates (57?±?2 per cent) the sedimentary carbon budget of the ESAS, the world’s largest continental shelf, overwhelming the marine and topsoil terrestrial components. Inverse modelling of the dual-carbon isotope composition of organic carbon accumulating in ESAS surface sediments, using Monte Carlo simulations to account for uncertainties, suggests that 44?±?10 teragrams of old carbon is activated annually from Ice Complex permafrost, an order of magnitude more than has been suggested by previous studies. We estimate that about two-thirds (66?±?16 per cent) of this old carbon escapes to the atmosphere as carbon dioxide, with the remainder being re-buried in shelf sediments. Thermal collapse and erosion of these carbon-rich Pleistocene coastline and seafloor deposits may accelerate with Arctic amplification of climate warming. 相似文献