全文获取类型
收费全文 | 16595篇 |
免费 | 1724篇 |
国内免费 | 24篇 |
专业分类
耳鼻咽喉 | 144篇 |
儿科学 | 574篇 |
妇产科学 | 524篇 |
基础医学 | 2431篇 |
口腔科学 | 274篇 |
临床医学 | 1950篇 |
内科学 | 3219篇 |
皮肤病学 | 191篇 |
神经病学 | 1293篇 |
特种医学 | 566篇 |
外国民族医学 | 3篇 |
外科学 | 2018篇 |
综合类 | 442篇 |
一般理论 | 11篇 |
预防医学 | 1899篇 |
眼科学 | 368篇 |
药学 | 1299篇 |
中国医学 | 13篇 |
肿瘤学 | 1124篇 |
出版年
2021年 | 206篇 |
2020年 | 144篇 |
2019年 | 241篇 |
2018年 | 256篇 |
2017年 | 208篇 |
2016年 | 230篇 |
2015年 | 247篇 |
2014年 | 349篇 |
2013年 | 522篇 |
2012年 | 693篇 |
2011年 | 783篇 |
2010年 | 474篇 |
2009年 | 411篇 |
2008年 | 672篇 |
2007年 | 707篇 |
2006年 | 636篇 |
2005年 | 669篇 |
2004年 | 660篇 |
2003年 | 659篇 |
2002年 | 568篇 |
2001年 | 538篇 |
2000年 | 554篇 |
1999年 | 470篇 |
1998年 | 230篇 |
1997年 | 181篇 |
1996年 | 171篇 |
1995年 | 177篇 |
1994年 | 163篇 |
1993年 | 156篇 |
1992年 | 407篇 |
1991年 | 405篇 |
1990年 | 411篇 |
1989年 | 352篇 |
1988年 | 379篇 |
1987年 | 360篇 |
1986年 | 320篇 |
1985年 | 298篇 |
1984年 | 263篇 |
1983年 | 216篇 |
1982年 | 126篇 |
1979年 | 217篇 |
1978年 | 175篇 |
1977年 | 147篇 |
1976年 | 156篇 |
1975年 | 154篇 |
1974年 | 153篇 |
1973年 | 175篇 |
1972年 | 142篇 |
1971年 | 129篇 |
1970年 | 137篇 |
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
31.
32.
The buffering capacity of tears collected from contact lens wearers was compared to that from non-contact lens wearers. Three groups of subjects were investigated: 6 subjects not wearing contact lenses, 3 subjects wearing rigid contact lenses, and 3 subjects wearing hydrogel contact lenses. Each of the 12 subjects provided, on 6 separate occasions, 100 microliters of tears. The pH of the tears was measured with a closed chamber, temperature stabilized micro-electrode system firstly on collection and then after titration with acid and base. In all, 28 titration steps across the acid-base spectrum were completed for each subject's tears on each occasion. These tear pH responses to acid-base challenge were compared to that of unbuffered distilled water for the same titration procedure. There was no statistically significant effect of contact lens wear on tear buffering capacity, but considerable inter-subject variability was noted. 相似文献
33.
Day cases: what are we counting? 总被引:1,自引:0,他引:1
34.
35.
36.
To assess the potential influence of diet and endogenous peptide anabolic hormone secretion on exercise-related differences in body composition, we compared levels of macronutrient intake, insulinlike growth factor I (IGF-I), and fat-free mass (FFM) and fat mass (FM) in matched groups of exercising women with and without secondary hypothalamic amenorrhea. Women were tightly matched according to somatotype and grouped into those with exercise amenorrhea (EXam, n = 6), exercise eumennorhea (EXeu, n = 5), and sedentary eumennorheic controls (SED, n = 5). Although no between-group difference was observed in FFM, the EXeu subjects had a significantly lower fat fraction and a significantly elevated FFM/FM ratio. Kilocaloric and protein intakes did not differ between groups, but dietary fat intake was lowest and carbohydrate intake highest in the EXam subjects. Dietary macronutrients were not correlated with the FFM/FM ratio. However, levels of insulinlike growth factor I were significantly correlated to the FFM/FM ratio and there was a clear trend for the hormone to be highest in the EXeu subjects. We conclude that differences in body composition between exercising women with and without exercise-induced hypothalamic-pituitary dysfunction were related to an alteration in IGF-I secretion, although differences in macronutrient intake might also be a factor. Further studies are warranted to elaborate upon the dietary and hormonal factors regulating the body composition response to exercise. 相似文献
37.
38.
39.
40.