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1.
Female rats injected with 1 mg of testosterone propionate on day 5 after birth weighed significantly more during the immediate postpubertal period than methandrostenolone-treated (1 mg) or vehicle-injected control females. There were no differences between groups in 24-hour intakes of food or water, when expressed on a per unit body weight basis. Testosterone- and methandrostenolone-treated rats ingested less water than controls in response to acute extracellular dehydration but not after cellular dehydration. The volume of the 'sexually dimorphic nucleus' of the preoptic area was significantly greater in brains taken from the two steroid-injected groups compared to control females. Testosterone had a stronger androgenic effect than methandrostenolone in terms of disrupting the estrous cycle. 相似文献
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Purification and biochemical characterization of recombinant hirudin produced by Saccharomyces cerevisiae 总被引:2,自引:0,他引:2
N Riehl-Bellon D Carvallo M Acker A Van Dorsselaer M Marquet G Loison Y Lemoine S W Brown M Courtney C Roitsch 《Biochemistry》1989,28(7):2941-2949
Recombinant hirudin was produced by the yeast Saccharomyces cerevisiae using the alpha-pheromone prepro sequence to direct its secretion into the culture medium. The secreted hirudin was isolated to greater than or equal to 95% purity as measured by 205-nm absorbance integration from a reverse-phase chromatogram. One major activity peak corresponding to the complete, correctly processed molecule and two minor activity peaks corresponding to C-terminally truncated forms were identified. The primary structure of the major peak, determined by N-terminal sequencing of tryptic peptides, was that predicted from the cDNA sequence, and the molecular mass analyzed by fast atom bombardment mass spectrometry (FAB-MS) was 6892.6 (calculated 6892.5). UV spectral analysis suggested that, in contrast to the natural molecule, recombinant hirudin produced by S. cerevisiae is not sulfated. 相似文献
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Reduction of nitrate byPseudomonas putrefaciens entrapped in composite agar layer/microporous membrane structures 总被引:1,自引:0,他引:1
Summary Composite structures consisting of aPseudomonas putrefaciens immobilized-cell agar layer bounded by a microporous membrane filter were used for water denitrification. With methanol as the C-source, one litre of high nitrate water (3 mM) was completely freed from NO
3
–
and NO
2
–
ions in 11 days at a rate of 90 mol N–NO
3
–
/day/g of agar gel, while no production of ammonium ions could be detected. When acetic acid was substituted for methanol, the denitrifying activity was lower. No noticeable contamination of the treated water due to cell leakage from the biocatalytic structures occurred during the incubation periods. 相似文献
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The investigation of several South African species of the tribe Inuleae afforded in addition to known compounds 16 new constituents. From Leontonyx a group of 9 new phloroglucinol derivatives, from Stoebe species two new p-hydroxyacetophenone, two thymol and two coumaric acid derivatives and from Relhania a new euparine-derivative were isolated. The structures are elucidated mainly by spectroscopic methods. The chemotaxonomic aspects are discussed briefly. The phloroglucinol derivatives, which in part are derived from geraniol, seem to be especially characteristic. 相似文献
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