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   6574篇
  免费   281篇
  国内免费   25篇
耳鼻咽喉   30篇
儿科学   115篇
妇产科学   57篇
基础医学   898篇
口腔科学   88篇
临床医学   387篇
内科学   1662篇
皮肤病学   102篇
神经病学   541篇
特种医学   289篇
外科学   1319篇
综合类   20篇
预防医学   238篇
眼科学   107篇
药学   345篇
中国医学   6篇
肿瘤学   676篇
  2023年   40篇
  2022年   66篇
  2021年   152篇
  2020年   89篇
  2019年   112篇
  2018年   135篇
  2017年   112篇
  2016年   138篇
  2015年   137篇
  2014年   193篇
  2013年   245篇
  2012年   401篇
  2011年   435篇
  2010年   220篇
  2009年   190篇
  2008年   363篇
  2007年   417篇
  2006年   411篇
  2005年   423篇
  2004年   391篇
  2003年   407篇
  2002年   354篇
  2001年   82篇
  2000年   66篇
  1999年   84篇
  1998年   96篇
  1997年   95篇
  1996年   86篇
  1995年   83篇
  1994年   65篇
  1993年   64篇
  1992年   64篇
  1991年   50篇
  1990年   62篇
  1989年   51篇
  1988年   45篇
  1987年   46篇
  1986年   33篇
  1985年   27篇
  1984年   33篇
  1983年   33篇
  1982年   35篇
  1981年   17篇
  1980年   26篇
  1979年   15篇
  1978年   17篇
  1977年   15篇
  1974年   24篇
  1973年   14篇
  1972年   15篇
排序方式: 共有6880条查询结果,搜索用时 937 毫秒
1.
Finasteride is standard medical treatment for androgenetic alopecia; however, no large studies with 5 years or more of follow up have been performed in Japan. The authors followed Japanese men with androgenetic alopecia treated with finasteride for 5 years to evaluate long‐term treatment efficacy. Of 903 men treated with finasteride (1 mg/day), 801 patients were evaluated over 5 years by modified global photographic assessment. Although the proportion of improvement was high (99.4%), modified global photographic assessment scores after 5 years of treatment were lower in patients with more advanced disease as measured by the modified Norwood–Hamilton scale. After separating patients into “sufficient” and “insufficient” efficacy groups according to the modified global photographic assessment score after 5 years (scores ≥6 and <6, respectively), multivariate analysis showed that independent risk factors of insufficient efficacy were age at start of treatment of 40 years or more (P = 0.021) and classification on the modified Norwood–Hamilton scale (P < 0.001), whereas presence of stress at start of treatment was a negative predictor (P = 0.025). In conclusion, continuous finasteride treatment for 5 years improved androgenetic alopecia with sustained effect among Japanese. Younger age and less advanced disease at start of treatment were the key predictors of higher finasteride efficacy.  相似文献   
2.
3.
4.
5.
We applied a forearm flap combined with a gracilis muscle flap for total reconstruction of the lower lip. The motor nerve of the gracilis muscle was repaired to the buccal branch in the cheek. The patient obtained good sphincter function for eating and speaking, and he could inflate a balloon without air leakage.  相似文献   
6.
One of the pyrimidine compounds, 2-piperadino-6-methyl-5-oxo-5,6-dihydro(7H)pyrrolo[3,4-d]pyrimidine (MS-818), has neurotropic effects in vitro. Therefore, we studied the effect of MS-818 on the regeneration of the peroneal nerve in C57BL/6J mice after a crush injury. Two test groups, which received a daily intraperitoneal injection of 5 mg/kg or 10 mg/kg MS-818, respectively, were compared with controls, which received daily intraperitoneal injections of physiological saline, over a 14-day period. The maximum foot-width ratio (crushed side/uncrushed side) was obtained on days 1, 8 and 14 after the crush injury, and the various morphometric parameters were evaluated at both 5 and 10 mm distal to the proximal portion of the crush site. The significant effects of MS-818 included a larger maximum foot width (P<0.04) and a greater number of unmyelinated axons per nerve at both levels (P<0.003) in both test groups than in controls. MS-818 had no significant effects on body weight, the increase of total transverse fascicular area after the crush injury, the total number of myelinated fibers with their size distributions, or the number of nuclei of Schwann cells and macrophages. Therefore, we conclude that MS-818 promotes axonal sprouting and elongation after a crush injury in mice.  相似文献   
7.
The current study was performed to understand the relationship between graft length placed within the bone tunnel and intraosseous graft healing in anterior cruciate ligament (ACL) reconstruction. Twenty-four adult beagle dogs were divided into two groups of 12 animals each. In each animal, ACL reconstruction using a 4-mm diameter autogenous flexor tendon graft was done in the left knee. In groups I and II, the graft having a length of 15 and 5 mm, respectively, was placed within the tibial tunnel. The proximal end of the graft was placed through the over-the-top route in all animals. In each group, five animals were sacrificed immediately after surgery, and the remaining seven were sacrificed at 6 weeks postoperatively. Biomechanical and histologic evaluations were performed. In pull out testing, the ultimate failure load and the linear stiffness of the graft-tibia complex harvested at 6 weeks were significantly greater than those harvested at the time-zero period. There were no significant differences in those parameters between groups I and II at 6 weeks. In each group, the perpendicular collagen fibers connecting the tendon to the bone tunnel wall were observed only in the narrow area located close to the intra-articular tunnel outlet. In conclusion, excessively long placement of the flexor graft within the bone tunnel does not result in an additional increase of anchoring strength and stiffness of the graft in ACL reconstruction.  相似文献   
8.
Microglia are only one type of professional immune cells in the central nervous system, functioning as scavenger cells that remove pathogens, and as antigen presenting cells that present brain-specific antigens to invading T cells. They also play a critical role in the pathophysiology of various CNS disorders as effector cells to destroy neural cells by secreting inflammatory cytokines, radicals, and glutamate. At the same time, they can protect neural functions by producing neurotrophic factors. Thus, to study the mechanisms for regulation of microglial functions may be useful for understanding the etiology and future therapeutic strategy for intractable neurological disorders.  相似文献   
9.
10.
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