全文获取类型
收费全文 | 584620篇 |
免费 | 57859篇 |
国内免费 | 211篇 |
出版年
2018年 | 6003篇 |
2017年 | 5860篇 |
2016年 | 7612篇 |
2015年 | 8830篇 |
2014年 | 10824篇 |
2013年 | 15938篇 |
2012年 | 18139篇 |
2011年 | 18787篇 |
2010年 | 12847篇 |
2009年 | 11604篇 |
2008年 | 16849篇 |
2007年 | 17318篇 |
2006年 | 16632篇 |
2005年 | 15731篇 |
2004年 | 15650篇 |
2003年 | 15122篇 |
2002年 | 14810篇 |
2001年 | 25795篇 |
2000年 | 25739篇 |
1999年 | 20634篇 |
1998年 | 7060篇 |
1997年 | 7243篇 |
1996年 | 6927篇 |
1995年 | 6291篇 |
1994年 | 6365篇 |
1993年 | 6183篇 |
1992年 | 17074篇 |
1991年 | 16734篇 |
1990年 | 16587篇 |
1989年 | 16589篇 |
1988年 | 15201篇 |
1987年 | 14405篇 |
1986年 | 13319篇 |
1985年 | 13553篇 |
1984年 | 10963篇 |
1983年 | 9372篇 |
1982年 | 6909篇 |
1981年 | 6076篇 |
1980年 | 5903篇 |
1979年 | 10317篇 |
1978年 | 8016篇 |
1977年 | 7237篇 |
1976年 | 7016篇 |
1975年 | 7832篇 |
1974年 | 8352篇 |
1973年 | 8248篇 |
1972年 | 7457篇 |
1971年 | 6687篇 |
1970年 | 5867篇 |
1969年 | 5558篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
911.
P D Blanchard R A Angus R L Morrison S K Frost-Mason J H Sheetz 《Pigment cell research / sponsored by the European Society for Pigment Cell Research and the International Pigment Cell Society》1991,4(5-6):240-246
Electron micrographs of skin from xanthic (gold) sailfin mollies revealed numerous xanthophores, as well as scattered melanophores. The melanophores were seen to contain premelanosomes in various stages of development. This is consistent with the fact that xanthic mollies have been shown to be tyrosinase positive. Melanosomes in xanthic mollies appear to develop by one of two pathways: 1) from an endoplasmic reticulum-derived vesicle which develops an internal lamellar framework, and 2) by fusion of multiple Golgi-derived vesicles which lack an internal lamellar framework. Analysis of the pigments in the skin of the xanthic mollies identified four colorless pteridine pigments (xanthopterin, isoxanthopterin, neopterin, and pterin) and a carotenoid with an absorbance spectrum similar to beta-carotene. It appears that, unlike some other poeciliid fishes, sailfin mollies do not use pteridine pigments for orange coloration. Rather, they appear to rely primarily on carotenoids. 相似文献
912.
913.
914.
Gerald R.V. Hammond Matthias P. Machner Tamas Balla 《The Journal of cell biology》2014,205(1):113-126
Polyphosphoinositides are an important class of lipid that recruit specific effector proteins to organelle membranes. One member, phosphatidylinositol 4-phosphate (PtdIns4P) has been localized to Golgi membranes based on the distribution of lipid binding modules from PtdIns4P effector proteins. However, these probes may be biased by additional interactions with other Golgi-specific determinants. In this paper, we derive a new PtdIns4P biosensor using the PtdIns4P binding of SidM (P4M) domain of the secreted effector protein SidM from the bacterial pathogen Legionella pneumophila. PtdIns4P was necessary and sufficient for localization of P4M, which revealed pools of the lipid associated not only with the Golgi but also with the plasma membrane and Rab7-positive late endosomes/lysosomes. PtdIns4P distribution was determined by the localization and activities of both its anabolic and catabolic enzymes. Therefore, P4M reports a wider cellular distribution of PtdIns4P than previous probes and therefore will be valuable for dissecting the biological functions of PtdIns4P in its assorted membrane compartments. 相似文献
915.
N R Nuriddinova I A Lapaeva M V Guseva B Kh Vafakulov 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1990,(7):50-54
The test for the evaluation of the toxicity of different types of pertussis preparations as manifested by their in vitro influence on mouse thymic cells (T test) has been finally worked out. The use of the T test has made it possible to reveal the nonstandard character of the production lots of adsorbed diphtheria-pertussis-tetanus vaccines, both whole-cell vaccine and Japanese acellular vaccine. The degree of the in vitro damaging action of pertussis preparations on mouse thymic cells greatly depends on the residual content of Bordetella pertussis nontoxoidized toxin which, in contrast to B. pertussis lipopolysaccharide and filamentous hemagglutinin, produces pronounced cytotoxic action on mouse thymic cells. 相似文献
916.
917.
918.
919.
Yu. V. Nesterov D. L. Teplyi 《Journal of Evolutionary Biochemistry and Physiology》2004,40(4):438-442
Analysis of parameters of metabolic function of lungs with respect to lipid metabolism was performed in rats under conditions of acute experimental emotional-nociceptive stress. Study of the stress-sensitivity of lungs in the comparative-age aspect has shown different extent of changes of several parameters of lipid metabolism in pulmonary tissue in animals of different age. The results of the study demonstrate areactivity and high stress-stability of lungs with respect to surface-active properties, free-radical processes, and lipase activity in early postnatal ontogenesis. 相似文献
920.