全文获取类型
收费全文 | 2151篇 |
免费 | 158篇 |
国内免费 | 3篇 |
专业分类
2312篇 |
出版年
2023年 | 9篇 |
2022年 | 34篇 |
2021年 | 62篇 |
2020年 | 25篇 |
2019年 | 48篇 |
2018年 | 56篇 |
2017年 | 51篇 |
2016年 | 50篇 |
2015年 | 118篇 |
2014年 | 103篇 |
2013年 | 126篇 |
2012年 | 181篇 |
2011年 | 164篇 |
2010年 | 97篇 |
2009年 | 76篇 |
2008年 | 105篇 |
2007年 | 81篇 |
2006年 | 77篇 |
2005年 | 69篇 |
2004年 | 59篇 |
2003年 | 67篇 |
2002年 | 57篇 |
2001年 | 40篇 |
2000年 | 37篇 |
1999年 | 32篇 |
1998年 | 18篇 |
1997年 | 22篇 |
1996年 | 19篇 |
1995年 | 17篇 |
1994年 | 14篇 |
1993年 | 15篇 |
1992年 | 39篇 |
1991年 | 24篇 |
1990年 | 15篇 |
1989年 | 25篇 |
1988年 | 25篇 |
1987年 | 36篇 |
1986年 | 25篇 |
1985年 | 14篇 |
1984年 | 25篇 |
1983年 | 26篇 |
1982年 | 9篇 |
1981年 | 15篇 |
1980年 | 11篇 |
1979年 | 16篇 |
1978年 | 10篇 |
1976年 | 7篇 |
1973年 | 10篇 |
1972年 | 12篇 |
1971年 | 7篇 |
排序方式: 共有2312条查询结果,搜索用时 0 毫秒
991.
Nitric oxide (NO) production during endotoxemia is associated with decreased total CYP content, CYP 1A1/2, 2B1/2, 2C6, 2C11, 3A1, and 3A2 mRNA, protein expression or activity which is prevented by NO synthase (NOS) inhibitors in rats. This study was conducted to determine if endotoxin-induced hypotension caused by NO production is mediated by inhibition of renal CYP 4A protein expression and activity. In conscious male Sprague-Dawley rats, endotoxin (10 mg/kg, ip) reduced mean arterial pressure (MAP), increased serum and renal nitrite levels, and inducible NOS (iNOS), and decreased renal CYP 4A1/A3 protein and CYP 4A activity. The selective iNOS inhibitor 1,3-PBIT (10 mg/kg, ip; 1h after endotoxin) prevented endotoxin-induced decrease in MAP, renal CYP 4A1/A3 protein level and CYP 4A activity and increase in systemic and renal nitrite production. The selective constitutive NOS (cNOS) inhibitor N(G)-nitro-L-arginine (L-NNA; 20 mg/kg, ip; 1 h after endotoxin) partially attenuated endotoxin-induced decrease in MAP. The selective CYP 4A inhibitor, aminobenzotriazole (50 mg/kg, ip; 1 h after endotoxin) diminished CYP 4A1/A3 protein level and CYP 4A activity. Aminobenzotriazole did not alter the endotoxin-induced decrease in MAP, but it reversed the effect of 1,3-PBIT in preventing endotoxin-induced fall in MAP and CYP 4A activity. These data suggest that the endotoxemia-induced increase in NO production primarily via iNOS suppresses renal CYP 4A expression and activity, and inhibition of iNOS with 1,3-PBIT restores renal CYP 4A protein and activity and MAP presumably due to increased production of arachidonic acid metabolites derived from CYP 4A. 相似文献
992.
Glanders, a notifiable highly contagious disease primarily of equids, is a disease of high zoonotic importance. Caused by
gram-negative bacillus, Burkholderia mallei, the disease was restricted to certain pockets of India with sporadic cases. Recently, a major outbreak of glanders occurred
in India starting from Maharashtra. Following clinical signs and symptoms and laboratory investigations on serum, nasal swab
and pus swab samples, it was confirmed as glanders among equines in Pune and Panchgani areas of Maharashtra. One pus sample
and three nasal swabs yielded B. mallei isolates while 23 serum samples were found positive for glanders by complement fixation test (CFT). The disease was successfully
controlled in the state by following strategies for prevention of spread of the disease to other areas in accordance with
Glanders and Farcy Act, 1899. Follow up of the occurrence in Maharashtra revealed negative status based on testing and physical
surveillance on more than 3,500 equines thereafter. Investigations indicated that the nidus of infection may be present elsewhere
in North India. 相似文献
993.
H. M. Schumacher K. A. Malik F. Van Iren 《World journal of microbiology & biotechnology》1995,11(6):703-705
H.M. Schumacher and K.A. Malik are with DSM-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Mascheroder Weg 1 B, 38124 Braunschweig, Germany; F. Van Iren is with the Institute of Molecular Plant Sciences, Leiden University, Wassenaarseweg 64, NL 2333 AL Leiden, The Netherlands. 相似文献
994.
Summary We discuss the involvement of several mammalian redox systems in the regulation of apoptosis. We focus especially on the role that mitochondria and the still ill-characterized plasma membrane NADH-oxidoreductase system play in apoptosis. The latter system was shown to respond to downregulation of mitochondrial function; inhibition of either system induces apoptosis. Apoptosis induced by inhibitors of the oxidase involves both Bcl-2 and calcineurin, two proteins recently shown to be capable of forming a tight complex. We suggest that Bcl-2 acts as an antioxidant, but in an electron sense rather than in an oxygen sense.Abbreviations GSH
glutathione
- GSSH
glutathione disulfide
- PARP
poly(ADP-ribosyl)transferase
- PMOR
plasma membrane NADH-oxidoreductase
- TNF
tumour necrosis factor 相似文献
995.
996.
Lo S. K.; Perlman M. B.; Niehaus G. D.; Malik A. B. 《Journal of applied physiology》1985,58(5):1421-1427
We examined the effect of fibrinolysis depression on thrombin-induced pulmonary microembolism in awake sheep prepared with chronic lung lymph fistulas. Fibrinolysis was depressed by an intravenous infusion (100 mg) of tranexamic acid [trans-4-(Aminomethyl)cyclohexanecarboxylic acid]. Pulmonary microembolism was induced by an intravenous infusion of alpha-thrombin (80 NIH U/kg) in normal (n = 7) and in tranexamic acid-treated (n = 6) sheep. Thrombin immediately increased pulmonary lymph flow (Qlym) in both groups. The increased Qlym was not associated with a change in the lymph-to-plasma protein concentration (L/P) ratio in the control group and with a small decrease in the tranexamic acid-treated group. The increases in Qlym and pulmonary transvascular protein clearance (Qlym X L/P ratio) in the tranexamic acid-treated group were greater and sustained at four- to fivefold above base line for 10 h after the thrombin and remained elevated at twofold above base line even at 24 h. In contrast, Qlym and protein clearance were transiently increased in the control group. The mean pulmonary arterial pressure (Ppa) and pulmonary vascular resistance (PVR) increased after thrombin in tranexamic acid-treated group; the increases in Ppa and PVR in the control group were transient. Protein reflection coefficient as determined by the filtration independent method decreased after thrombin in tranexamic acid-treated sheep (n = 5), indicating an increased vascular permeability to proteins. We conclude that prolongation of microthrombi retention in the pulmonary circulation results in an increased vascular permeability to proteins. Both increased vascular permeability and vascular hydrostatic pressure are important determinants of the increases in Qlym and transvascular protein clearance after thrombin-induced pulmonary microembolism. 相似文献
997.
998.
999.
K. A. Malik 《World journal of microbiology & biotechnology》1991,7(6):629-632
The author is with the DSM-Deutsche Sammlung von Mikroorganismen und Zellkulturen GmbH, Mascheroder Weg 1b, D-3300 Braunschweig, Germany. 相似文献
1000.
Post-vaccinal encephalitis, although relatively uncommon, is a known adverse event associated with many live, attenuated smallpox vaccines. Although smallpox vaccination ceased globally in 1980, vaccine manufacture has resumed in response to concerns over the possible use of smallpox virus as an agent of bioterrorism. To better support the production of safer smallpox vaccines, we previously reported the development of a mouse model in which a relatively attenuated vaccine strain (Dryvax®) could be discerned from a more virulent laboratory strain (WR). Here we have further tested the performance of this assay by evaluating the neurovirulence of several vaccinia virus-based smallpox vaccines spanning a known range in neurovirulence for humans. Our data indicate that testing of 10–100 pfu of virus in mice following intracranial inoculation reliably assesses the virus's neurovirulence potential for humans. 相似文献