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   15298篇
  免费   1257篇
  国内免费   214篇
耳鼻咽喉   151篇
儿科学   580篇
妇产科学   288篇
基础医学   1224篇
口腔科学   419篇
临床医学   1900篇
内科学   3542篇
皮肤病学   336篇
神经病学   793篇
特种医学   498篇
外科学   2926篇
综合类   191篇
一般理论   5篇
预防医学   886篇
眼科学   804篇
药学   994篇
中国医学   51篇
肿瘤学   1181篇
  2023年   153篇
  2022年   103篇
  2021年   314篇
  2020年   230篇
  2019年   227篇
  2018年   372篇
  2017年   330篇
  2016年   371篇
  2015年   385篇
  2014年   544篇
  2013年   703篇
  2012年   699篇
  2011年   759篇
  2010年   542篇
  2009年   654篇
  2008年   571篇
  2007年   538篇
  2006年   590篇
  2005年   506篇
  2004年   441篇
  2003年   428篇
  2002年   391篇
  2001年   394篇
  2000年   373篇
  1999年   351篇
  1998年   278篇
  1997年   267篇
  1996年   368篇
  1995年   322篇
  1994年   239篇
  1993年   164篇
  1992年   279篇
  1991年   298篇
  1990年   223篇
  1989年   266篇
  1988年   239篇
  1987年   243篇
  1986年   238篇
  1985年   194篇
  1984年   201篇
  1983年   155篇
  1982年   118篇
  1981年   99篇
  1980年   128篇
  1979年   105篇
  1978年   105篇
  1977年   98篇
  1976年   102篇
  1975年   102篇
  1974年   110篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
1.
2.
3.
The numbers of free flap donor site as well as their indications are constantly increasing. Despite increasing popularity of microvascular reconstructive procedures, literature lacks clear and objective outcome criteria. This paper reports on a simple outcome classification that has become a routine part of the unit's large workload of microvascular outcome recording. The classification was formed through a retrospective analysis of 241 consecutive cases from 2000 to 2001 and is a five graded numerical classification. Grade 1 equates to total success without co-morbidity and grade 5 to a major complication such as amputation, etc., whatever the status of the flap itself. From 2002 to 2005 the classification was prospectively used on 527 consecutive cases with ease of integration into routine clinical practice. The Classification would enable a more objective record keeping thus analysis of the outcome. It would allow a more realistic comparison of different techniques or donor types as well set a benchmarking level for further improvement of the results.  相似文献   
4.
Endoscopic clips have been used mainly for control of gastrointestinal (GI) bleeding and occasionally for closure of GI perforations. However, closure of spontaneous esophageal perforation (Boerhaave's syndrome) by clipping has not been reported. We described successful non-surgical closure of spontaneous esophageal perforation by endoscopic clipping in a patient with bilateral pyopneumothorax and septicemia.  相似文献   
5.
6.
BACKGROUND: Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery. METHODS: We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D. RESULTS: Mean patient age was 43 +/- 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level 相似文献   
7.
Molecular characterization of Wuchereria bancrofti is essential to develop suitable anti-filarial drugs and vaccines. We describe here isolation, sequence analysis and cloning of a partial cDNA of an enzyme superoxide dismutase from this parasite. The immunoscreening of a lambda zap W. bancrofti microfilarial (Mf) cDNA library with microfilaremic sera had resulted in the isolation of several seroreactive clones including, WbSOD. This clone contained a 309 bp insert and showed significant nucleotide and deduced amino acid sequence homologies to the superoxide dismutases of other nematode parasites. The antioxidant property of this enzyme may have important contribution in the defense mechanism of the parasite against host immune response.  相似文献   
8.
9.
OBJECTIVES: to examine the management and outcome of patients with traumatic popliteal artery pseudoaneurysms with delayed presentation. MATERIALS: over a 2-year period 7 patients with traumatic popliteal pseudoaneurysms presenting to a tertiary referral unit after a delay of 1 month were reviewed. METHODS: a retrospective review of clinical records. RESULTS: the median interval between injury and presentation was 1.5 months (range 1-24 months). Penetrating trauma from gunshot wounds was the cause of the initial vascular injury in 6 patients and a stab wound in one. All patients had large pseudoaneurysms of more than 8 cm filling the popliteal fossa with variable degrees of fixed flexion deformity (FFD) of the knee. Severe FFD of more than 40 degrees was noted in 2 patients and 3 others had mild flexion deformities of 10 to 20 degrees. Six patients underwent repair of the pseudoaneurysm. One patient required an above knee amputation due to an infected false aneurysm. There were no deaths or graft related complications. Despite aggressive post-operative physiotherapy only 2 patients were able to completely straighten the leg at the time of discharge. CONCLUSIONS: in patients with neglected popliteal artery pseudoaneurysms, morbidity is associated with the pre-operative degree of fixed flexion deformity of the knee.  相似文献   
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