全文获取类型
收费全文 | 6140篇 |
免费 | 546篇 |
国内免费 | 18篇 |
专业分类
耳鼻咽喉 | 71篇 |
儿科学 | 218篇 |
妇产科学 | 144篇 |
基础医学 | 654篇 |
口腔科学 | 152篇 |
临床医学 | 766篇 |
内科学 | 1128篇 |
皮肤病学 | 99篇 |
神经病学 | 569篇 |
特种医学 | 261篇 |
外科学 | 931篇 |
综合类 | 127篇 |
一般理论 | 2篇 |
预防医学 | 738篇 |
眼科学 | 146篇 |
药学 | 328篇 |
中国医学 | 6篇 |
肿瘤学 | 364篇 |
出版年
2023年 | 60篇 |
2022年 | 76篇 |
2021年 | 228篇 |
2020年 | 98篇 |
2019年 | 165篇 |
2018年 | 200篇 |
2017年 | 143篇 |
2016年 | 145篇 |
2015年 | 173篇 |
2014年 | 213篇 |
2013年 | 272篇 |
2012年 | 329篇 |
2011年 | 336篇 |
2010年 | 174篇 |
2009年 | 203篇 |
2008年 | 279篇 |
2007年 | 263篇 |
2006年 | 226篇 |
2005年 | 238篇 |
2004年 | 225篇 |
2003年 | 197篇 |
2002年 | 157篇 |
2001年 | 138篇 |
2000年 | 160篇 |
1999年 | 126篇 |
1998年 | 83篇 |
1997年 | 64篇 |
1996年 | 80篇 |
1995年 | 58篇 |
1994年 | 72篇 |
1993年 | 64篇 |
1992年 | 87篇 |
1991年 | 95篇 |
1990年 | 86篇 |
1989年 | 89篇 |
1988年 | 88篇 |
1987年 | 78篇 |
1986年 | 77篇 |
1985年 | 59篇 |
1984年 | 59篇 |
1983年 | 60篇 |
1982年 | 46篇 |
1981年 | 43篇 |
1980年 | 39篇 |
1979年 | 58篇 |
1978年 | 56篇 |
1976年 | 30篇 |
1974年 | 30篇 |
1973年 | 33篇 |
1970年 | 29篇 |
排序方式: 共有6704条查询结果,搜索用时 31 毫秒
101.
102.
103.
Wanda Kwan Ulrike Tr?ger Dimitrios Davalos Austin Chou Jill Bouchard Ralph Andre Aaron Miller Andreas Weiss Flaviano Giorgini Christine Cheah Thomas M?ller Nephi Stella Katerina Akassoglou Sarah J. Tabrizi Paul J. Muchowski 《The Journal of clinical investigation》2012,122(12):4737-4747
In Huntington disease (HD), immune cells are activated before symptoms arise; however, it is unclear how the expression of mutant huntingtin (htt) compromises the normal functions of immune cells. Here we report that primary microglia from early postnatal HD mice were profoundly impaired in their migration to chemotactic stimuli, and expression of a mutant htt fragment in microglial cell lines was sufficient to reproduce these deficits. Microglia expressing mutant htt had a retarded response to a laser-induced brain injury in vivo. Leukocyte recruitment was defective upon induction of peritonitis in HD mice at early disease stages and was normalized upon genetic deletion of mutant htt in immune cells. Migration was also strongly impaired in peripheral immune cells from pre-manifest human HD patients. Defective actin remodeling in immune cells expressing mutant htt likely contributed to their migration deficit. Our results suggest that these functional changes may contribute to immune dysfunction and neurodegeneration in HD, and may have implications for other polyglutamine expansion diseases in which mutant proteins are ubiquitously expressed. 相似文献
104.
James W. Bellew Molly Allen Austin Biefnes Sara Grantham James Miglin Dylan Swartzell 《Physiotherapy theory and practice》2018,34(7):551-558
Objective: Efficacy of neuromuscular electrical stimulation (NMES) is limited by the discomfort of electrically elicited contractions. Most studies of tolerance to NMES have examined stimulation to maximal tolerance. NMES efficiency is the amount of elicited force at a specific level of tolerance. This study is the first to describe and examine such. Design: A repeated measures design was used. Electrically elicited force (EEF) was measured using three waveforms: burst-modulated alternating current (BMAC), pulsed current (PC), and burst-modulated pulsed current (BMPC). EEF at a tolerance rating of 5/10 on a visual analog scale (VAS) was recorded. The dependent variables were EEF up to 5/10 VAS, current amplitude at 5/10, and percent maximal isometric force at 5/10. Results: EEF and percent maximal voluntary isometric force were significantly greater with BMPC versus BMAC (p = 0.001 and 0.004). No differences were noted between PC and BMAC or BMPC and PC. Amplitude was significantly greater with BMAC compared to BMPC and PC (p = 0.003 and 0.015). No difference in amplitude was noted between PC and BMPC. Conclusion: For the same level of discomfort, BMPC yielded one-third greater muscle force than BMAC and at a lesser current amplitude. These data evidence a greater efficiency for BMPC than BMAC. 相似文献
105.
Wesley H. Self MD MPH Joyce Mickanin MSN RN Carlos G. Grijalva MD MPH Freda H. Grant MT ASCP Michelle C. Henderson MSN RN Glenda Corley MT ASCP D. Glen Blaschke II MD Candace D. McNaughton MD MPH Tyler W. Barrett MD MSCI Thomas R. Talbot MD MPH Barbara R. Paul MD 《Academic emergency medicine》2014,21(3):274-282
106.
Emily A. Davidson C. Austin Pickens 《International journal of food sciences and nutrition》2018,69(2):183-191
Delta-5 (D5D) and delta-6 (D6D) desaturase are key enzymes in fatty acid (FA) metabolism. Dietary eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) may alter tissue FA composition via D5D and D6D. The purpose was to determine the relationship between dietary EPA?+?DHA, estimated desaturase activities of various tissues and the reflection of desaturase activity in the red blood cell (RBC). Mice were fed diets with increasing percent of energy from EPA?+?DHA. Phospholipid FA composition of heart, muscle, spleen, lung, adipose tissues and RBC were analysed. D5D and D6D enzyme activity estimates (EAE) were calculated as the ratio of 20:4/20:3 and 20:3/18:2, respectively. D5D EAE decreased in all tissues, except muscle, with increasing dietary EPA?+?DHA. RBC D5D EAE positively correlated with D5D EAE in all tissues. RBC D6D EAE positively correlated with muscle and inversely correlated with adipose D6D EAE. Our findings suggest differential influence of dietary EPA?+?DHA upon tissue desaturase activities. 相似文献
107.
108.
Antidepressants have been associated with weight gain, but the causes are unclear. The aims of this study were to assess the association of antidepressant use with energy intake, macronutrient diet composition, and physical activity. We used data on medication use, energy intake, diet composition, and physical activity for 3073 eligible adults from the 2005–2006 National Health and Nutrition Examination Survey (NHANES). Potential confounding variables, including depression symptoms, were included in the models assessing energy intake, physical activity, and sedentary behavior. Antidepressant users reported consuming an additional (mean ± S.E.) 215 ± 73 kcal/day compared to non-users (p = 0.01). There were no differences in percent calories from sugar, fat, or alcohol between the two groups. Antidepressant users had similar frequencies of walking or biking, engaging in muscle-strengthening activities, and engaging in moderate or vigorous physical activity. Antidepressant users were more likely to use a computer for ≥2 h/day (OR 1.77; 95% CI: 1.09–2.90), but TV watching was similar between the two groups. These results suggest increased energy intake and sedentary behavior may contribute to weight gain associated with antidepressant use. Focusing on limiting food intake and sedentary behaviors may be important in mitigating the weight gain associated with antidepressant use. 相似文献
109.
110.
Gregory Welter PE BCEE Myra Socher BS EMT/P Patricia Needham MT HEM Steve Bieber MS MPA Heidi Bonnaffon MS 《Journal of healthcare risk management》2013,32(4):5-14
The purpose of this article is to outline the criticality of water supply in sustained operations of healthcare facilities, particularly during community emergencies, and to advocate for enhanced cross‐sector support from the water utilities in meeting this need. Information and ideas presented here were developed in the course of a regional project sponsored by the Metropolitan Washington Council of Governments (MWCOG) for development of emergency water supply operations plans for critical water uses in the Washington, DC, area. 相似文献