全文获取类型
收费全文 | 1686329篇 |
免费 | 114189篇 |
国内免费 | 2421篇 |
专业分类
耳鼻咽喉 | 23529篇 |
儿科学 | 55765篇 |
妇产科学 | 47820篇 |
基础医学 | 256701篇 |
口腔科学 | 45480篇 |
临床医学 | 146188篇 |
内科学 | 323879篇 |
皮肤病学 | 36077篇 |
神经病学 | 126080篇 |
特种医学 | 65425篇 |
外国民族医学 | 410篇 |
外科学 | 257665篇 |
综合类 | 32898篇 |
现状与发展 | 2篇 |
一般理论 | 399篇 |
预防医学 | 123675篇 |
眼科学 | 38993篇 |
药学 | 128782篇 |
2篇 | |
中国医学 | 3359篇 |
肿瘤学 | 89810篇 |
出版年
2018年 | 16257篇 |
2016年 | 13869篇 |
2015年 | 15821篇 |
2014年 | 21650篇 |
2013年 | 32732篇 |
2012年 | 45925篇 |
2011年 | 49666篇 |
2010年 | 29138篇 |
2009年 | 27029篇 |
2008年 | 47284篇 |
2007年 | 51495篇 |
2006年 | 51781篇 |
2005年 | 50442篇 |
2004年 | 48773篇 |
2003年 | 47397篇 |
2002年 | 46410篇 |
2001年 | 74491篇 |
2000年 | 76456篇 |
1999年 | 64592篇 |
1998年 | 18252篇 |
1997年 | 16082篇 |
1996年 | 16366篇 |
1995年 | 15414篇 |
1994年 | 14490篇 |
1993年 | 13555篇 |
1992年 | 51590篇 |
1991年 | 51980篇 |
1990年 | 51555篇 |
1989年 | 50220篇 |
1988年 | 46743篇 |
1987年 | 45938篇 |
1986年 | 43578篇 |
1985年 | 41653篇 |
1984年 | 31046篇 |
1983年 | 26872篇 |
1982年 | 15562篇 |
1981年 | 13866篇 |
1979年 | 29578篇 |
1978年 | 20831篇 |
1977年 | 17778篇 |
1976年 | 17237篇 |
1975年 | 19348篇 |
1974年 | 22587篇 |
1973年 | 21770篇 |
1972年 | 20546篇 |
1971年 | 19293篇 |
1970年 | 18009篇 |
1969年 | 17143篇 |
1968年 | 16165篇 |
1967年 | 14331篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
81.
Angiotensin Converting Enzyme Inhibitors: Animal Experiments Suggest a New Pharmacological Treatment for Alcohol Abuse in Humans 总被引:1,自引:0,他引:1
G. Spinosa MSc E. Perlanski Dipl Tech. F. H. H. Leenen MD R. B. Stewart MSc L. A. Grupp DSc 《Alcoholism, clinical and experimental research》1988,12(1):65-70
The prevalence of heavy alcohol consumption is a major problem of increasing proportions throughout the world. Although alcohol sensitizing drugs and more recently serotonin uptake inhibitors are drug interventions with some following, their long term beneficial consequences have yet to be demonstrated. In recent years, we have demonstrated that manipulating activity in the renin-angiotensin system will dramatically alter voluntary alcohol consumption in rats. Based on these findings, the present study evaluated the ability of a class of drugs known as the angiotensin converting enzyme inhibitors to reduce voluntary alcohol drinking in laboratory animals. These drugs prevent the conversion of angiotensin I to angiotensin II. They have been licensed for use in Europe and North America and are indicated in the treatment of hypertension. Our experiments showed that both captopril (Capoten, Squibb) and enalapril (Vasotec, Merck Sharpe & Dohme) can reduce alcohol drinking in both normotensive and hypertensive animals regardless of whether the pattern of intake is in a bout or of a less exaggerated nature. Furthermore, this change in alcohol intake can occur without concomitant changes in blood pressure, plasma renin activity, overall fluid balance, or the distribution and metabolism of alcohol. Taken together these findings suggest that the angiotensin converting enzyme inhibitors should be evaluated in a clinical setting for they may prove to be a useful new treatment or treatment adjunct for alcohol abuse in humans. 相似文献
82.
A mechanistic QSAR study on N-nitrosamines (NA) was performed with the aid of the semiempirical MINDO/3 method. Both the chemical reactivity and the transport in biological medium were taken into account. The parent NA molecules and their first reaction intermediates in the metabolic activation pathway were examined for possible determinants of the relative carcinogenic potency. The correlations found support the previous suggestions concerning the metabolic C alpha radical hydroxylation of NA. The role of transport properties in the early stage of NA biotransformation was also demonstrated. 相似文献
83.
84.
85.
86.
87.
Milton G. Mutchnick MD Horchang H. Lee MD 《Alcoholism, clinical and experimental research》1988,12(1):155-158
Concanavalin A-induced lymphocyte proliferation was studied in 25 patients with alcoholic hepatitis or compensated alcoholic cirrhosis. Nine alcoholics without evidence of liver disease were also evaluated. A nonlinear correlation equation, which was natural logarithmic, was applied to individual dose-response proliferation curves and permitted comparisons between patient groups and controls. The proliferative response in all patient groups was significantly lower when compared to healthy controls and was independent of the presence or absence of liver disease. This suggests that some changes in immune function observed in alcoholics may be linked to the direct effects of alcohol on the immune system rather than to the associated liver disease. 相似文献
88.
Macrophage NRAMP1 and its role in resistance to microbial infections 总被引:12,自引:0,他引:12
89.
90.
A. HAZIOT I. KATZ G. W. RONG X. Y. LIN J. SILVER & S. M. GOYERT 《Scandinavian journal of immunology》1997,46(3):242-245
Membrane-bound CD14 acts as a receptor for lipopolysaccharide (LPS) on monocytes/macrophages and neutrophils. Studies have suggested that the activation of monocytes/macrophages by the binding of LPS to membrane-bound CD14 may require the association of a signal-transducing molecule with membrane-bound CD14. The observation that non-CD14 expressing cells, such as endothelial cells, can nevertheless be activated by a complex of LPS and a soluble form of CD14 (sCD14) suggests that the receptor for this complex may be identical to the signal transducing molecule associated with membrane-bound CD14. The studies described show that two CD14-specific MoAb are able to block the LPS-induced activation of endothelial cells but do not affect the response of monocytes to LPS. This suggests that the interaction of the sCD14:LPS complex with endothelial cells is distinct from the interaction of membrane-bound CD14 with its putative signal-transducing molecule. 相似文献