全文获取类型
收费全文 | 195099篇 |
免费 | 1901篇 |
国内免费 | 94篇 |
专业分类
耳鼻咽喉 | 1256篇 |
儿科学 | 6933篇 |
妇产科学 | 3230篇 |
基础医学 | 18783篇 |
口腔科学 | 2133篇 |
临床医学 | 13611篇 |
内科学 | 35541篇 |
皮肤病学 | 1023篇 |
神经病学 | 17977篇 |
特种医学 | 9857篇 |
外科学 | 32293篇 |
综合类 | 2401篇 |
一般理论 | 1篇 |
预防医学 | 18772篇 |
眼科学 | 3234篇 |
药学 | 10941篇 |
中国医学 | 647篇 |
肿瘤学 | 18461篇 |
出版年
2022年 | 205篇 |
2021年 | 354篇 |
2020年 | 224篇 |
2019年 | 294篇 |
2018年 | 22201篇 |
2017年 | 17569篇 |
2016年 | 19755篇 |
2015年 | 1217篇 |
2014年 | 1179篇 |
2013年 | 1304篇 |
2012年 | 7763篇 |
2011年 | 21894篇 |
2010年 | 19298篇 |
2009年 | 11919篇 |
2008年 | 20256篇 |
2007年 | 22535篇 |
2006年 | 1514篇 |
2005年 | 3086篇 |
2004年 | 4249篇 |
2003年 | 5103篇 |
2002年 | 3305篇 |
2001年 | 1147篇 |
2000年 | 1304篇 |
1999年 | 922篇 |
1998年 | 471篇 |
1997年 | 407篇 |
1996年 | 312篇 |
1995年 | 243篇 |
1994年 | 241篇 |
1993年 | 181篇 |
1992年 | 560篇 |
1991年 | 569篇 |
1990年 | 597篇 |
1989年 | 540篇 |
1988年 | 460篇 |
1987年 | 442篇 |
1986年 | 428篇 |
1985年 | 417篇 |
1984年 | 249篇 |
1983年 | 203篇 |
1982年 | 113篇 |
1980年 | 97篇 |
1979年 | 181篇 |
1978年 | 118篇 |
1977年 | 105篇 |
1974年 | 97篇 |
1973年 | 96篇 |
1970年 | 128篇 |
1969年 | 111篇 |
1968年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Y Nishizawa T Shoji S Tanaka M Yamashita A Morita M Emoto T Tabata T Inoue H Morii 《American journal of kidney diseases》1998,31(4):655-661
Leptin is a newly found hormone secreted by adipocytes that regulates food intake, thermogenesis, and body fat. We measured plasma leptin levels in 103 patients with chronic renal failure treated by hemodialysis and 167 age- and gender-matched healthy control subjects to examine the impact of renal failure on plasma leptin levels and the influence of leptin on body composition measured by dual-energy X-ray absorptiometry. Hemodialysis patients showed a significant decrease in both body fat mass and lean body mass compared with those of the control subjects. Plasma leptin was significantly elevated in the hemodialysis group over the controls. In both groups, leptin was higher in female than male subjects, and it correlated positively with percent body fat. The subjects were divided into six categories according to percent body fat, and plasma leptin levels were compared between the two groups in the same category. Leptin of hemodialysis patients was significantly higher than that of the control subjects in the percent body fat categories of 30 or greater, whereas there was no statistically significant difference in leptin concentrations in the lower percent body fat categories. This was also true in the comparison in each gender, and leptin levels in female subjects showed a more remarkable difference between the hemodialysis and control groups in obese categories. Multiple regression analysis in all subjects indicated that plasma leptin levels were independently affected by percent body fat, plasma insulin concentration, gender, and renal failure. The positive impact of renal failure on leptin remained significant in the subjects with percent body fat of 30 or greater in the multiple regression model, whereas it was no longer significant in the remaining lean subjects. In multiple regression analysis of factors affecting fat mass index and lean mass index, leptin level was selectively associated with fat mass index, but not with lean mass index, regardless of percent body fat ranges. These results indicate that renal failure is an important factor affecting plasma leptin levels, especially in obese female subjects, and that hyperleptinemia was closely related to fat mass but not to lean body mass in hemodialysis patients. 相似文献
12.
13.
T Uno M Takamatsu Y Inoue Y Kawahata K Iuchi G Tsukamoto 《Journal of medicinal chemistry》1987,30(12):2163-2169
A series of 6-fluoro- and 6,8-difluoro-7-(azole substituted)-1,4-dihydro-4-oxo-3-quinolinecarboxylic acids were prepared. Structure-activity relationship studies indicated that the antibacterial potency was better when the 6,8-substituents were fluorine atoms and the 7-substituent was either 1-imidazolyl, 20, or 4-methyl-1-imidazolyl, 25. From the results of studies on pharmacokinetic profile and toxicity, 20 and 25 were found to possess excellent antibacterial activities and to show high blood levels after oral administration to mice with low toxicity. 相似文献
14.
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
15.
16.
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
17.
18.
19.
Sergio Barroilhet Adrián Cano-Prous Salvador Cervera-Enguix Maria João Forjaz Francisco Guillén-Grima 《Social psychiatry and psychiatric epidemiology》2009,44(12):1051-1065
Introduction
This paper presents the results of a study on the psychometric properties of an authorized Spanish version of the McMaster Family Assessment Device, a self-report measure of family functioning. 相似文献20.