全文获取类型
收费全文 | 235580篇 |
免费 | 7660篇 |
国内免费 | 4765篇 |
专业分类
耳鼻咽喉 | 1608篇 |
儿科学 | 7195篇 |
妇产科学 | 3578篇 |
基础医学 | 23595篇 |
口腔科学 | 2736篇 |
临床医学 | 20591篇 |
内科学 | 40086篇 |
皮肤病学 | 1260篇 |
神经病学 | 19754篇 |
特种医学 | 11116篇 |
外国民族医学 | 52篇 |
外科学 | 34883篇 |
综合类 | 13270篇 |
现状与发展 | 19篇 |
一般理论 | 5篇 |
预防医学 | 22239篇 |
眼科学 | 4581篇 |
药学 | 16147篇 |
38篇 | |
中国医学 | 4017篇 |
肿瘤学 | 21235篇 |
出版年
2024年 | 215篇 |
2023年 | 1066篇 |
2022年 | 2329篇 |
2021年 | 3411篇 |
2020年 | 2585篇 |
2019年 | 2247篇 |
2018年 | 23947篇 |
2017年 | 19289篇 |
2016年 | 21311篇 |
2015年 | 3848篇 |
2014年 | 4454篇 |
2013年 | 3865篇 |
2012年 | 11711篇 |
2011年 | 26040篇 |
2010年 | 21744篇 |
2009年 | 13820篇 |
2008年 | 22655篇 |
2007年 | 24730篇 |
2006年 | 3607篇 |
2005年 | 5185篇 |
2004年 | 5303篇 |
2003年 | 6207篇 |
2002年 | 4032篇 |
2001年 | 1645篇 |
2000年 | 1827篇 |
1999年 | 1785篇 |
1998年 | 1187篇 |
1997年 | 1155篇 |
1996年 | 783篇 |
1995年 | 741篇 |
1994年 | 738篇 |
1993年 | 450篇 |
1992年 | 599篇 |
1991年 | 509篇 |
1990年 | 509篇 |
1989年 | 399篇 |
1988年 | 367篇 |
1987年 | 286篇 |
1986年 | 235篇 |
1985年 | 209篇 |
1984年 | 116篇 |
1983年 | 80篇 |
1982年 | 69篇 |
1981年 | 41篇 |
1980年 | 58篇 |
1979年 | 44篇 |
1938年 | 61篇 |
1934年 | 34篇 |
1932年 | 57篇 |
1930年 | 47篇 |
排序方式: 共有10000条查询结果,搜索用时 6 毫秒
91.
Annemieke Smit-van Oosten Winston W. Bakker Harry van Goor 《Transplant international》2002,15(12):602-609
Ischemic injury plays an important role in chronic renal transplant failure (CRTF). Down-regulation of ecto-adenosine triphosphatase (ATPase) in combination with up-regulation of ecto-5'-nucleotidase is a hallmark of ischemic injury. We studied the expression of renal ecto-5'-nucleotidase and ecto-ATPase in experimental renal transplantation. Fisher 344-to-Lewis allografted rats were either treated with an angiotensin-converting enzyme inhibitor (ACEi) or left untreated. Lewis-to-Lewis syngrafted rats served as controls. Untreated allografted rats developed proteinuria, glomerulosclerosis, and mild intimal hyperplasia. ACEi completely prevented focal and segmental glomerulosclerosis (FGS) and proteinuria, but significantly enhanced intimal hyperplasia. Untreated allografted rats revealed marked vascular ecto-5'-nucleotidase activity, which increased with ACEi. Vascular ecto-5'-nucleotidase activity was absent in syngrafted animals. Ecto-5'-nucleotidase activity correlated well with intimal hyperplasia. Glomerular ecto-ATPase expression was significantly reduced in untreated allografted rats compared to syngrafted rats and correlated well with the extent of FGS. ACEi prevented reduction in glomerular ecto-ATPase. We found de-novo expression of ecto-5'-nucleotidase at sites of renal intimal hyperplasia. Glomerular ecto-ATPase expression was markedly reduced in allografted rats and was prevented by ACEi. These enzyme expression patterns suggest local ischemic damage in experimental CRTF. 相似文献
92.
Whether the ATP-sensitive potassium channel opener pinacidil can provide myocardial protective effects in prolonged isolated global ischemic rat heart was investigated. On modified isolated rat working heart model, 40 hearts were divided into four groups randomly: Hyperpolarized arrest H-K solution containing pinacidil (50 tmol/L) (P1 and P2) and depolarized arrest St. Thomas‘ solution (S1 and S2) subjected to 15 C hypothermia, 60 min (P1 and S1) or 120 min (P1 and S2) of ischemia and 30 min reperfusion. The experimental indices included cardioplegic efficiency, cardiac function, coronary blood flow, myocardial enzyme release, myocardial water and ATP content. Hyperpolarized arrest provided significantly better recovery of cardiac function than depolarized arrest.Postischemic coronary flow and myocardial ATP content were higher. The arrest time of electro-mechanical activities were longer than depolarized arrest. There were no differences among the groups in myocardial water contents. The hyperpolarized arrest solution containing pinacidil can provide a marked myocardial protective effect during prolonged hypothermic myocardial ischemia. 相似文献
93.
目的评价紫杉醇洗脱冠状动脉支架(TAXUStmBoston公司产品)应用于急性冠状动脉综合症病人的临床疗效及安全性。方法自2003年5月至2004年12月接受TAXUS支架治疗的94例急性冠状动脉综合症患者,观察术后即刻效果、术后6个月心脏性死亡、心肌梗塞、再次血管重建及冠状动脉造影复查情况。病例中包括ST段抬高的急性心肌梗塞27例,非ST段抬高的急性心肌梗死8例,不稳定心绞痛59例。结果支架植入成功率为99%,术中和随访期间无死亡,术后1例出现亚急性血栓,1例晚期血栓致心肌梗塞,另有5例随访中进行了血管重建术,6个月主要心脏不良事件(MACE)发生率7.4%。术后6~7个月23例的冠状动脉造影复查再狭窄率为13.0%(支架内为8.6%),靶病变重建率为2.7%。结论应用TAXUS支架治疗急性冠状动脉综合症是安全和有效的,支架内再狭窄率明显低于普通金属支架。 相似文献
94.
J. Bryan Page 《Journal of urban health》2005,82(3):iii35-iii43
Contemporary discourse contains numerous examples of use of the concept of culture by social and behavioral scientists. Simple reification, where the speaker makes culture into a thing capable of action exemplifies one usage in public discourse. Some quantitative social scientists attempt to characterize people’s cultural identities by means of a single categorical variable, which often “lumps” people into categories such as “Hispanic” or “Black” that in fact have numerous culturally bounded subcategories. Approaches that emphasize cultural process are preferable to those who attempt to categorize; more complex measures of acculturation help investigators to make convincing analyses of circumstances in which health disparities occur. Examples in which investigators make appropriate use of cultural characterizations demonstrate their utility in investigating health disparities in Haitian American women, injecting and noninjecting drug users, Hispanic youth, and adult Hispanics at risk of HIV infection. Focus on culture in the study of health disparities can identify entanglements between structural factors such as poverty and lack of education and cultural factors such as beliefs about health. Qualitative methods coupled with quantitative methods have great potential to improve investigators’ grasp of cultural nuance while capturing the distribution of qualitatively derived behaviors. 相似文献
95.
96.
97.
Pilar Nicolás 《Hereditary cancer in clinical practice》2007,5(3):144-152
The specific characteristics of genetic data lead to ethical-legal conflicts in the framework of genetic diagnosis. Several international organisations, including UNESCO and the Council of Europe, have enacted rules referring to the use of genetic information. This paper discusses possible legal and ethical criteria that could be used in genetic testing. 相似文献
98.
目的 了解大剂量尿激酶静脉溶栓治疗急性心肌梗塞疗效.方法 对符合溶栓条件急性心肌梗塞25例病人,在常规治疗基础上,给予100万单位尿激酶静脉输注.结果 治愈23例,有效率92%.结论 使用大剂量尿激酶静脉溶栓治疗急性心肌梗塞,临床效果确切. 相似文献
99.
100.
Sergio Barroilhet Adrián Cano-Prous Salvador Cervera-Enguix Maria João Forjaz Francisco Guillén-Grima 《Social psychiatry and psychiatric epidemiology》2009,44(12):1051-1065