全文获取类型
收费全文 | 134791篇 |
免费 | 5757篇 |
国内免费 | 182篇 |
出版年
2018年 | 1759篇 |
2017年 | 1897篇 |
2016年 | 3917篇 |
2015年 | 7602篇 |
2014年 | 7368篇 |
2013年 | 7755篇 |
2012年 | 7703篇 |
2011年 | 5013篇 |
2010年 | 3798篇 |
2009年 | 3363篇 |
2008年 | 3105篇 |
2007年 | 3055篇 |
2006年 | 3044篇 |
2005年 | 8822篇 |
2004年 | 7505篇 |
2003年 | 5599篇 |
2002年 | 3237篇 |
2001年 | 2626篇 |
2000年 | 2016篇 |
1999年 | 2720篇 |
1998年 | 868篇 |
1997年 | 598篇 |
1992年 | 2668篇 |
1991年 | 2734篇 |
1990年 | 2750篇 |
1989年 | 2643篇 |
1988年 | 2567篇 |
1987年 | 2360篇 |
1986年 | 2155篇 |
1985年 | 2168篇 |
1984年 | 1566篇 |
1983年 | 1276篇 |
1982年 | 853篇 |
1981年 | 822篇 |
1980年 | 662篇 |
1979年 | 1556篇 |
1978年 | 1137篇 |
1977年 | 930篇 |
1976年 | 916篇 |
1975年 | 1249篇 |
1974年 | 1338篇 |
1973年 | 1334篇 |
1972年 | 1312篇 |
1971年 | 1251篇 |
1970年 | 1065篇 |
1969年 | 1108篇 |
1968年 | 1035篇 |
1967年 | 983篇 |
1966年 | 773篇 |
1965年 | 588篇 |
排序方式: 共有10000条查询结果,搜索用时 194 毫秒
91.
R M Agüero G Picó E Guibert J L Corchs 《Comparative biochemistry and physiology. B, Comparative biochemistry》1987,86(1):7-10
The interaction of ANS with rat hepatocytes in time was studied by fluorescence spectroscopy. The intercept of the first linear portion of the time curve of interaction showed a positive value over all the ANS concentration range employed. This value was maintained after cellular disruption by homogenization. It was affected by ionic strength, pH, and divalent cation in the incubation medium, all conditions affecting the cellular surface. These data suggest that this phenomenon might be a binding of the compound to the hepatocytes surface. Due to the time constant and its disappearance after cellular disruption the other slower component of the curve seems to correspond to a process of translocation across the membrane. 相似文献
92.
G Kh Goldshte?ne I B Tsorin G G Chichkanov 《Biulleten' eksperimental'no? biologii i meditsiny》1986,101(2):177-179
The experiments on rats with a 3-day myocardial infarction caused by the left coronary artery ligation have shown that multiple lidocaine and pyromecaine injections according to a given scheme decrease the size of the necrosis area. Drug effects were not related to their action on the blood supply of the ischemic area. 相似文献
93.
R V Balasiavichius A I Dagis A I Tole?kis A K Prashkiavichius 《Biulleten' eksperimental'no? biologii i meditsiny》1985,99(3):294-296
The influence of malate and cytochrome c on fatty acid oxidation under control and ischemic conditions was investigated. In the medium without malate, cytochrome did not make fatty acid oxidation decreased during ischemia return to normal. Oxidation in the media containing malate and cytochrome did not differ from control only when it was measured after preliminary oxidation of endogenous substrates. The ratio of palmitoyl-CoA and palmitoyl carnitine to the respiration rates at state 3 was unchanged at 60 min ischemia. Apparently, no changes in carnitine acyltransferase playing a role in oxidation of palmitoyl-CoA took place. Thus, the decrease of fatty acid oxidation at early periods of ischemia is largely caused by a reduction in the content of cytochrome c and intermediates of Krebs cycle in the mitochondria. 相似文献
94.
J. Dierschke T. Krüger F. Hüttmann F. Bairlein Kerstin Müller G. Scheiffarth H. -W. Helb W. Irsch W. Lantermann B. Haubitz W. Winkel und J. Haffer 《Journal of Ornithology》2003,144(4):484-498
Ohne Zusammenfassung 相似文献
95.
V. v. Borbás P. L. Wiedermann Franz Hüfer E. Hackel 《Plant Systematics and Evolution》1890,40(11):427-428
Ohne Zusammenfassung 相似文献
96.
The receptor for asialoglycoproteins was isolated from murine liver and was purified by means of biospecific chromatography on sepharose-Asialo-orosomucoid. The obtained receptor with an absorption maximum at 277 nm binds to the nonreducing terminal galactosyl residues of glycoproteins similar to the receptors from liver of other mammalians. The interaction between this receptor and desialylated glycoproteins requires the presence of calcium. The dependence of specific binding on the concentration of [125I]acialo-orosomucoid used as a ligand gives a saturating curve. The dissociation constant for the receptor-ligand complex is 0.4 X 10(-9) M. Similar to asialo-orosomucoid, the receptor binds the p-aminophenyl-beta-D-galactopyranoside derivatives of bovine serum albumin, ovalbumin and acid alpha-glucosidase synthesized by us earlier. Possible use of the asialoglycoprotein receptor as a highly specific carrier transporting the modified acid alpha-glucosidase to hepatocyte lysosomes is discussed. 相似文献
97.
Michael D. Jensen Ji?í Bajnárek Sang Yeoup Lee Soren Nielsen Christina Koutsari 《Journal of lipid research》2009,50(9):1863-1869
The relationship between overnight postabsorptive (fasting) respiratory exchange ratio (RER) and plasma FFA concentrations was addressed using data from three separate protocols, each of which involved careful control of the antecedent diet. Protocol 1 examined the relationship between fasting RER and the previous daytime RER. In Protocol 2 fasting, RER and plasma palmitate concentrations were measured in 29 women and 31 men (body mass index <30 kg·m−2). Protocol 3 analyzed data from Nielsen et al. (Nielsen, S., Z. K. Guo, J. B. Albu, S. Klein, P. C. O''Brien, M. D. Jensen. 2003. Energy expenditure, sex and endogenous fuel availability in humans. J. Clin. Invest. 111: 981-988.) to understand how fasting RER and palmitate concentrations relate within individuals during four consecutive measurements. The results were as follows: 1) Fasting RER was correlated (r = 0.74, P < 0.001) with the previous day''s average RER, and less so with RER variability. 2) Fasting RER was correlated (r = −0.39, P = 0.007) with fasting plasma palmitate concentrations. 3) The pattern of the RER/palmitate relationship was similar within individuals and between individuals; a negative slope was observed significantly more often than a positive slope (χ2 test; P < 0.001). Our findings suggest that, despite a fixed food quotient, the slight departures from energy equilibrium in a controlled General Clinical Research Center environment can effect plasma FFA concentrations. We suggest that including indirect calorimetry as part of FFA metabolism studies may aid in data interpretation. 相似文献
98.
99.