全文获取类型
收费全文 | 1481篇 |
免费 | 87篇 |
国内免费 | 1篇 |
出版年
2022年 | 21篇 |
2021年 | 32篇 |
2020年 | 18篇 |
2019年 | 25篇 |
2018年 | 32篇 |
2017年 | 31篇 |
2016年 | 49篇 |
2015年 | 49篇 |
2014年 | 68篇 |
2013年 | 80篇 |
2012年 | 96篇 |
2011年 | 95篇 |
2010年 | 56篇 |
2009年 | 57篇 |
2008年 | 63篇 |
2007年 | 70篇 |
2006年 | 47篇 |
2005年 | 66篇 |
2004年 | 43篇 |
2003年 | 35篇 |
2002年 | 27篇 |
2001年 | 17篇 |
2000年 | 24篇 |
1999年 | 23篇 |
1997年 | 7篇 |
1993年 | 6篇 |
1992年 | 17篇 |
1991年 | 25篇 |
1990年 | 24篇 |
1989年 | 30篇 |
1988年 | 17篇 |
1987年 | 19篇 |
1986年 | 19篇 |
1985年 | 21篇 |
1984年 | 15篇 |
1983年 | 18篇 |
1982年 | 13篇 |
1981年 | 10篇 |
1980年 | 22篇 |
1979年 | 24篇 |
1978年 | 11篇 |
1977年 | 14篇 |
1976年 | 15篇 |
1975年 | 14篇 |
1974年 | 20篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1971年 | 12篇 |
1970年 | 9篇 |
1969年 | 9篇 |
排序方式: 共有1569条查询结果,搜索用时 15 毫秒
31.
N S Agarwal V J Hruby R Katz W Klee M Nirenberg 《Biochemical and biophysical research communications》1977,76(1):129-135
Nucleoli isolated from livers of rats injected intraperitoneally with one dose of thioacetamide had a five-fold increase in the rate of RNA synthesis when compared with livers of rats treated with saline or CCl4. The stimulation was maximal 24 hours after treatment and decreased to control values 73 hours after treatment. The enhanced level of nucleolar activity was maintained at that level when thioacetamide was injected daily. Along with the increase in the endogenous activity there was a 7-fold increase in the “free” RNA polymerase I activity determined by blocking the bound enzyme with actinomycin D (7). The nucleoli of the thioacetamide-treated rats offer a useful model of modulation of ribosomal gene function. 相似文献
32.
P.K. Dudeja S.N. Sanyal N. Agarwal T.N. Rao D. Subrahmanyam G.K. Khuller 《Chemico-biological interactions》1980,31(2):203-208
Four furocoumarins, two having a linear molecule, psoralen and 8-methylpsoralen and two having an angular molecule, angelicin and 4,5′-dimethylangelicin were tested for mutagenesis in Escherichia coli B wild type and in various strains deficient in known repair systems. The results indicate that both monoadducts and crosslinks are mutagenic. The mutagenic efficiency of the furocourmarins ranks in the following order 8-methylpsoralen > psoralen > angelicin > 4,5′-dimethylangelicin. 相似文献
33.
Abstract— The effects of feeding dietary wheat and Bengal gram proteins to pregnant rats on brain protein and glutamic acid metabolism in 15-, 17- and 19-day fetuses were investigated. Wheat and Bengal gram diets resulted in loss of brain weight with decreased DNA, RNA, protein, free x amino N and deficits in the activities of brain glutamine synthetase, glutaminase I. glutaminase II and glutamate decarboxylase at all the gestational ages studied without any change in glutamine transferase activity. The concentrations of the amino acids alanine, glutamic acid, glutamine and GABA were found to be significantly lower on wheat and Bengal gram diets than the control on a 10% casein diet. The wheat with lysine and Bengal gram with methionine, cystine and tryptophan resulted in similar mean values of all the characteristics studied to the mean values observed in rats on the control diet. However, glutaminase I activity remained significantly low on lysine fortified wheat diet, and aspartic acid content was found to increase on both fortified and unfortified wheat and Bengal gram diets. A 20% casein diet showed increased brain weight, DNA. RNA. protein and free x amino N concentrations as compared with the 10% casein diet, while the other parameters remained unchanged. 相似文献
34.
Dharam P. Agarwal Doris Meier-Tackmann Shoji Harada H. Werner Goedde 《Human genetics》1981,59(2):170-171
Summary Human liver alcohol dehydrogenase (ADH) variants were screened in random autopsy specimens from 53 North German and 34 Japanese individuals. Based on pH-activity profile and electrophoretic pattern, only ADH2 and ADH3 variants were detected. In relatively fresh specimens, an anodic band or -ADH band was also observed. The recently reported new molecular forms collectively called ADHIndianapolis (Bosron et al. 1980) could not be demonstrated and therefore may be confined hitherto only to the American black population.This paper is dedicated to Professor Dr. Dr. H. Baitsch on his 60th birthday 相似文献
35.
Tamal K. Roy Sarita Agarwal Deepak K. Agarwal 《Biochemical and biophysical research communications》1982,106(3):888-894
Centperazine or diethylcarbamazine, administered at various dose levels to rats inhibited the activity of succinate dehydrogenase significantly in 4 hrs in liver. Centperazine also inhibited the activity of cytochrome-c oxidase but stimulated the activity of benzo (a) pyrene hydroxylase in liver. In kidneys, activities of succinate dehydrogenase, cytochrome-c oxidase and aniline hydroxylase were significantly inhibited by centperazine only, however, the activity of benzo (a) pyrene hydroxylase was inhibited by both the drugs. These drugs had no effect on the activity of aminopyrene N-demethylase and cytochrome P-450 contents of liver and kidneys. 相似文献
36.
37.
A Agarwal B L Tekwani O P Shukla S Ghatak 《Indian journal of experimental biology》1990,28(3):245-248
S. cervi showed particulate bound Ca2+ ATPase and Na+,K(+)-ATPase activities while Mg2+ ATPase was detected in traces. ATPase of S. cervi was also differentiated from the nonspecific p-nitrophenyl phosphatase activity. Female parasite and microfilariae exhibited higher Ca2+ ATPase and Na+,K(+)-ATPase activities than the male adults and the enzyme Na+,K(+)-ATPase was mainly concentrated in the gastrointestinal tract of the filarial parasite. Na+,K(+)-ATPase of the filariid was ouabain-sensitive while Ca2(+)-ATPase activity was regulated by concentration of Ca2+ ions and inhibited by EGTA. Phenothiazines, viz. trifluoperazine, promethazine and chlorpromazine caused significant inhibition of Ca2+ ATPase and Na+,K(+)-ATPase. Diethylcarbamazine was a potent inhibitor of these ATPases. Mebendazole, levamisole and centperazine also caused significant inhibition of the ATPases indicating this enzyme system as a common target for the action of anthelmintic drugs. 相似文献
38.
R Agarwal M Athar D R Bickers H Mukhtar 《Biochemical and biophysical research communications》1990,173(1):34-41
In recent years, choloroaluminum phthalocyanine tetrasulfonate (A1PCTS) has been shown to be a promising photosensitizer for the photodynamic therapy (PDT) of cancer. Although its mechanism of photodynamic action is not well defined, A1PCTS is going to be under clinical trials of PDT. In this study, in vitro addition of A1PCTS to a suspension of rat epidermal microsomes followed by irradiation with red light (approximately 675 nm) resulted in significant destruction of cytochrome P-450 and associated monooxygenase activities. The photodestructive effect was dependent on both the dose of A1PCTS and the duration of light exposure. Studies using various quenchers of reactive oxygen species showed that only scavengers of singlet oxygen such as histidine, 2,5-dimethylfuran, beta-carotene and sodium azide afforded substantial protection against photodestruction. Our data indicate the direct involvement of singlet oxygen in the A1PCTS-mediated photodestructive process. 相似文献
39.
Four major ALDH isozymes have been identified in human tissues using starch gel electrophoresis and isoelectric focusing. The isozyme bands have been termed as ALDH I, II, III and IV according to their decreasing electrophoretic migration and increasing isoelectric point. The isozymes have been partially purified via preparative isoelectric focusing. Kinetic characteristics of ALDH I and II were found to be quite similar to ALDH enzyme 2 and enzyme 1 described earlier by Greenfield and Pietruszko (Biochem Biophys Acta, 35–45 1977). ALDH III and IV showed a very high Km for propionaldehyde (1.0–1.5 mM at pH 9.5) and were not inhibited by disulfiram at pH 9.5. A variant phenotype of ALDH which lacked in isozyme I was detected in various tissues from Japanese individuals. Comparative kinetic properties of normal and variant enzyme are given. 相似文献
40.