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991.
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993.
The leaves of Strychnos wallichiana Steud. ex. DC. from Bangladesh contain icajine and novacine as their major alkaloids. Smaller amounts of strychnine, brucine, pseudostrychnine, pseudobrucine, N-methyl-sec.-pseudo-β-colubrine, 14-hydroxyicajine, strychnine N-oxide, and brucine N-oxide are also present. The new bases 14 hydroxynovacine and icajine N-oxide have been isolated. 相似文献
994.
Pseudomonas aeruginosa and P. denitrificans accumulate more protoheme and considerably more protoporphyrin during anaerobic growth under denitrifying conditions than during aerobic growth. In Escherichia coli, the small accumulation of protoporphyrin and protoheme which occurs during anaerobic growth is slightly stimulated by nitrate and markedly stimulated by oxygen. 相似文献
995.
996.
Receptors for estradiol, progesterone and dihydrotestosterone have been demonstrated in normal growing breasts of young females below 25 years. 相似文献
997.
998.
Differential susceptibilities of spinal cord neurons to retinoic acid-induced survival and differentiation 总被引:3,自引:0,他引:3
In a previous study, we demonstrated trophic effects of vitamin A and its active metabolite, retinoic acid (RA), on perinatal rat spinal cord neurons and astrocytes in vitro. We now report that RA increases the survival of cholinergic neurons without affecting that of GABAergic neurons. These results were supported by measured levels of acetylcholinesterase (AChE), choline acetyltransferase (ChAT), and glutamic acid decarboxylase (GAD) activities, key enzymes of acetylcholine and gamma-aminobutyric acid metabolism, respectively, which showed RA-induced increases in AChE and ChAT levels but no elevations of GAD activity. In contrast to these phenotype-specific effects, most neurons showed RA-induced increases in neuritic outgrowth, density, and silver impregnation. Taken together, these results demonstrate neurotransmitter-specific and generalized effects of RA on developing CNS neurons. 相似文献
999.
1000.
N. Munier 《Ecological Indicators》2011,11(5):1020-1026
This paper proposes a methodology for establishing a set of sustainability indicators as a baseline to measure the state of a city, and after appropriate actions are taken, to assess performance, to determine if changes point to improvements regarding goals. The methodology starts with choosing a procedure for identification, scope, evaluation, and level of indicators to build the initial dataset. As a second step, produces a reduced set of indicators, complying with all criteria imposed, and selected under the condition of extracting the maximum amount of information from the initial dataset. 相似文献