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991.
Are all plant populations metapopulations? 总被引:2,自引:1,他引:1
992.
993.
P Sinibaldi R Muraro M Centanni M G Giganti 《Bollettino della Società italiana di biologia sperimentale》1983,59(1):112-116
The behaviour of Na+/K+ ATPase during cell growth has been studied. Human cultured fibroblasts were used in the presence or absence of EGF. Sample and control cultures were stopped by gathering and washing the cells with tris buffer. Homogenates were tested for Na+/K+ ATPase activity by the method of incubating and for the -SH groups content (Ellman). Na+/K+ ATPase activity that slightly increases in the controls is strongly reduced by the addition of EGF. The behaviour shows evidence for a double mechanism of action: I) involvement of the cAMP system 2) decrease of the -SH group availability. 相似文献
994.
995.
W J Koopman M H Gillis J R David 《Journal of immunology (Baltimore, Md. : 1950)》1973,110(6):1609-1614
996.
Isolation of mucin from human submaxillary secretions 总被引:2,自引:0,他引:2
M M Baig R J Winzler W M Rennert 《Journal of immunology (Baltimore, Md. : 1950)》1973,111(6):1826-1833
997.
Pressure-flow relationships in the isolated canine trachea 总被引:1,自引:0,他引:1
998.
999.
The copigment present in the crystalline blue pigment isolated from Blue Boy cornflowers (Centaurea cyanus L.) was identified as apigenin 4′-O-β-glucoside 7-O-β-d-glucuronide. The NMR spectra of aryl glucuronides are discussed. 相似文献
1000.
The presence of prostaglandins (PGs) was determined in gastric juice obtained from 3 conscious dogs, provided with a chronic gastric fistula. Outputs of acid (mequiv min?1) and PGs (pg min?1) were measured in gastric secretions stimulated by pentagastrin (100 or 200 ng kg?1min?1). Prostaglandin activity was estimated, after extraction and thin layer chromatography, by radioimmuno-assay of the PGB formed by treatment with alkali. Tritiated PGs were added to gastric juice for the purpose of correcting for PGs recovery. Using this method, the minimum mass of PGB which could be satisfactorily distinguished from zero was 25 pg. Prostaglandins A2 and E2 were present in pentagastrin-activated gastric secretions and averaged (mean ± SE, n = 8) 200.7 ± 18.1 and 260.1 ± 18.0 pg min?1 respectively. The identity of PGA2 and PGE2 was confirmed by gas liquid chromatography combined with mass spectrometry. The amount of PGE2 converted to PGA2 during extraction, separation and conversion procedures was estimated from the amount of [3H] PGA2 found when only [3H] PGE2 had been added to a sample of gastric juice and averaged 14.5% ± 2.0. Our preliminary results support the possibility that PGE2 and PGA2 may be of physiological importance in the regulation of canine gastric secretions. 相似文献