首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   212231篇
  免费   4479篇
  国内免费   2656篇
耳鼻咽喉   1317篇
儿科学   7080篇
妇产科学   3541篇
基础医学   21054篇
口腔科学   2213篇
临床医学   16977篇
内科学   36717篇
皮肤病学   998篇
神经病学   18569篇
特种医学   10167篇
外国民族医学   23篇
外科学   32787篇
综合类   8059篇
现状与发展   12篇
一般理论   3篇
预防医学   20208篇
眼科学   3683篇
药学   13344篇
  15篇
中国医学   2491篇
肿瘤学   20108篇
  2024年   106篇
  2023年   566篇
  2022年   1322篇
  2021年   1684篇
  2020年   1377篇
  2019年   1232篇
  2018年   23058篇
  2017年   18442篇
  2016年   20504篇
  2015年   2624篇
  2014年   2837篇
  2013年   2532篇
  2012年   9732篇
  2011年   23849篇
  2010年   20507篇
  2009年   12894篇
  2008年   21416篇
  2007年   23651篇
  2006年   2373篇
  2005年   4085篇
  2004年   4657篇
  2003年   5561篇
  2002年   3493篇
  2001年   1133篇
  2000年   1408篇
  1999年   1222篇
  1998年   831篇
  1997年   885篇
  1996年   593篇
  1995年   577篇
  1994年   530篇
  1993年   354篇
  1992年   348篇
  1991年   406篇
  1990年   408篇
  1989年   323篇
  1988年   267篇
  1987年   248篇
  1986年   202篇
  1985年   164篇
  1984年   118篇
  1983年   98篇
  1982年   56篇
  1981年   43篇
  1980年   67篇
  1979年   34篇
  1978年   33篇
  1938年   60篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
32.

Background  

Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure.  相似文献   
33.

Background  

Skin and soft tissue infections are increasingly prevalent clinical problems, and it is important for health care practitioners to be well trained in how to treat skin abscesses. A realistic model of abscess incision and drainage will allow trainees to learn and practice this basic physician procedure.  相似文献   
34.
The objective of this study is to compare the effects of three different anesthetic combinations on the electroretinogram in the same animals under similar laboratory conditions. Thiopental–isoflurane (TI), medetomidine–ketamine (MK), and xylazine–ketamine (XK) were used on each of 12 healthy miniature schnauzer dogs (MS) with a period of at least 3 weeks in between subsequent anesthesia protocols, using the Dog Standard Protocol. The scotopic ERGs consisted of scotopic low stimulus strength (S) responses designated S1, S2, S3, S4, and S5, at 1, 5, 10, 15, and 20 min after dark adaptation, respectively, and scotopic standard stimulus strength (S-ST) responses. The photopic ERGs consisted of a photopic single flash (P) response and 31 Hz flicker (P-FL) responses. For S-ST (2.5 cd s/m2), the amplitude of the a-wave using TI was significantly lower than that using MK (adjusted P = 0.05) and XK (adjusted P = 0.03), and the implicit time of the a-wave was significantly shorter than that using MK (adjusted P = 0.04). For P (2.5 cd s/m2), the amplitude of the b-wave using XK was significantly higher than that using MK (adjusted P = 0.01). The implicit times of the b-wave using TI was significantly longer and shorter than that of MK for S1, S2 and P-FL and for S4 and S-ST, respectively, and than that of XK for S2 and P-FL and for S5 and S-ST, respectively. The results of the present study showed that TI affected both the amplitude and the implicit time of the a-wave for S-ST and the implicit time of the b-wave relatively more so than was the case when using XK or MK. Therefore, it appears that either XK or MK could be advantageous to use rather than TI for clinical studies.  相似文献   
35.
Abstract Background: Primary shoulder hemiarthroplasty is an established treatment modality for complex fractures of the proximal humerus. Long-term functional outcome is often disappointing. However, little is known about social implications particularly in the elderly. Methods: A single-institution case series of consecutive geriatric patients (age > 70 years) treated with shoulder hemiarthroplasty for complex fractures of the proximal humerus between 1994 and 1997 was analysed. Postoperative morbidity, long-term function, radiological outcome and social implications were evaluated. Results: Seventy-seven patients fulfilled the study criteria. Median age at the time of operation was 80 years (range 70–93 years). Systemic and local postoperative complications were observed in 8% including 2 patients (3%) with revision surgery. Postoperative mortality was 1%. Forty-eight patients (62%) were available for follow-up (median 49 months, range 25–80 months), 22 (29%) died from causes unrelated to hemiarthroplasty before follow-up and 7 patients (9%) did not attend follow-up examination. Median Constant-Murley score was 41 points (range 17–77 points). Long-term results concerning pain were satisfying. The Oxford shoulder score ranged from 14 to 40 (median 30). Forty-one patients (85%) still lived in their original environment and managed their daily life independently despite poor shoulder function. Four patients (8%) lived in a retirement home and 3 (6%) in a nursery home. Eighty percent of our patients were still able to use public transportation, do the daily shopping and wash their whole body by themselves. Conclusion: Most patients managed their daily life independently despite poor shoulder function.  相似文献   
36.
当归对衰老小鼠脑组织细胞凋亡及胸腺指数的影响   总被引:2,自引:0,他引:2  
目的:研究当归的抗衰老作用及作用机制。方法:用D—半乳糖诱导小鼠制成衰老模型,同时给予不同剂量的当归水煎剂,观察当归对脑组织细胞凋亡及胸腺指数的影响。结果:当归能明显抑制小鼠脑组织细胞凋亡,提高胸腺指数。结论:当归具有抗衰老作用。  相似文献   
37.
38.
39.

Background  

The telomeric region of mouse chromosome 12 has previously shown frequent allelic loss in murine lymphoma. The Bcl11b gene has been identified and suggested as a candidate tumor suppressor gene within this region. In this study, we aimed to elucidate whether Bcl11b is mutated in lymphomas with allelic loss, and whether the mutations we detected conferred any effect on cell proliferation and apoptosis.  相似文献   
40.
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号