全文获取类型
收费全文 | 1613914篇 |
免费 | 132299篇 |
国内免费 | 2662篇 |
专业分类
耳鼻咽喉 | 21800篇 |
儿科学 | 53118篇 |
妇产科学 | 46386篇 |
基础医学 | 229702篇 |
口腔科学 | 47425篇 |
临床医学 | 142043篇 |
内科学 | 317217篇 |
皮肤病学 | 34305篇 |
神经病学 | 131578篇 |
特种医学 | 65201篇 |
外国民族医学 | 474篇 |
外科学 | 245669篇 |
综合类 | 39850篇 |
现状与发展 | 4篇 |
一般理论 | 551篇 |
预防医学 | 123565篇 |
眼科学 | 36744篇 |
药学 | 122086篇 |
3篇 | |
中国医学 | 2997篇 |
肿瘤学 | 88157篇 |
出版年
2018年 | 15110篇 |
2016年 | 13194篇 |
2015年 | 15403篇 |
2014年 | 21104篇 |
2013年 | 31892篇 |
2012年 | 43382篇 |
2011年 | 45678篇 |
2010年 | 26844篇 |
2009年 | 25771篇 |
2008年 | 43776篇 |
2007年 | 45978篇 |
2006年 | 46737篇 |
2005年 | 45380篇 |
2004年 | 44712篇 |
2003年 | 42765篇 |
2002年 | 41815篇 |
2001年 | 75827篇 |
2000年 | 78457篇 |
1999年 | 66528篇 |
1998年 | 17856篇 |
1997年 | 16445篇 |
1996年 | 16391篇 |
1995年 | 16085篇 |
1994年 | 15151篇 |
1993年 | 14276篇 |
1992年 | 55484篇 |
1991年 | 53840篇 |
1990年 | 52609篇 |
1989年 | 50889篇 |
1988年 | 47280篇 |
1987年 | 46598篇 |
1986年 | 44329篇 |
1985年 | 42892篇 |
1984年 | 32077篇 |
1983年 | 27614篇 |
1982年 | 16195篇 |
1981年 | 14480篇 |
1980年 | 13615篇 |
1979年 | 30505篇 |
1978年 | 21100篇 |
1977年 | 17812篇 |
1976年 | 16728篇 |
1975年 | 17607篇 |
1974年 | 21520篇 |
1973年 | 20703篇 |
1972年 | 18872篇 |
1971年 | 17794篇 |
1970年 | 16316篇 |
1969年 | 15280篇 |
1968年 | 13965篇 |
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
231.
R J Aitken 《British medical bulletin》1990,46(3):654-674
Our understanding of the causes of male infertility and our ability to develop an appropriate range of diagnostic tests are both dependent upon a knowledge of the cellular mechanisms responsible for the regulation of human sperm function. This review examines the intra- and extracellular factors regulating four separate components of human sperm function: sperm transport, sperm-egg recognition, the acrosome reaction and sperm-oocyte fusion. Within each of these areas the fundamental nature of the process, the control mechanisms involved, the availability of appropriate diagnostic tests and the relationship with human infertility have been considered. 相似文献
232.
233.
Mycenon, a new metabolite from a Mycena species TA 87202 (basidiomycetes) as an inhibitor of isocitrate lyase 总被引:1,自引:0,他引:1
Mycenon (C11H5Cl3O3), a new inhibitor of isocitrate lyase (EC 4.1.3.1) was isolated from the culture broth of a basidiomycete, Mycena sp. Mycenon is a novel chlorinated benzoquinone derivative which is also active against bacteria and fungi. Malate synthase (EC 4.1.3.2) the second key enzyme of the glyoxylate cycle was not affected by mycenon. Isocitrate lyase preparations from plants, bacteria and fungi were sensitive. The following Ki-values for mycenon have been determined: Ricinus communis, 5.2 microM; Acinetobacter calcoaceticus, 11 microM; Neurospora crassa, 7.4 microM. The structure of mycenon has been determined by a single crystal X-ray analysis. 相似文献
234.
235.
L R?stam R V Luepker M B Mittelmark D M Murray J S Slater H Blackburn 《American journal of preventive medicine》1988,4(5):249-254
To determine the potential effect of screening on referral patterns, an adult population sample (4,404 men, 5,164 women, 20-69 years of age) was systematically recruited and screened for hypercholesterolemia and then analyzed by different cholesterol referral recommendations. Using levels suggested by the Lipid Research Clinics Coronary Primary Prevention Trial (greater than or equal to 265 mg/dL), 7.3% of men and 5.8% of women would be referred for follow-up. With the suggested recommendations of the National Cholesterol Education Program (NCEP), (greater than or equal to 200 mg/dL), 49.2% of men and 40.2% of women would be referred. The use of age-related definitions of the NIH Consensus Conference on Lipid Lowering results in 28.0% referrals in men and 21.8% in women. From this population, hypercholesterolemia subjects (greater than or equal to 265 mg/dL at screening; n = 624) were invited for a second cholesterol determination (58% returned), which found 36% below the 265 mg/dL level. Population screening for cholesterol is likely to produce large numbers of patients for follow-up, with the actual numbers strongly dependent on cutoff levels and age-sex distributions. Referral and follow-up of these patients may place a significant load on an unprepared health care community. 相似文献
236.
237.
238.
239.
Post-traumatic retinal detachment occurs frequently as a late consequence of progressive vitreous changes, especially following penetrating injuries. Occasionally, it develops soon after the trauma, without preceding proliferative vitreoretinopathy, is based on posterior vitreous detachment and morphologically resembles an idiopathic retinal detachment. It is possible that the posterior vitreous detachment in these cases is encouraged by the presence of intravitreal hemorrhage. 相似文献
240.