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   1901852篇
  免费   136640篇
  国内免费   4574篇
耳鼻咽喉   23963篇
儿科学   60948篇
妇产科学   50232篇
基础医学   267095篇
口腔科学   52832篇
临床医学   172965篇
内科学   376060篇
皮肤病学   41670篇
神经病学   151942篇
特种医学   72686篇
外国民族医学   258篇
外科学   289068篇
综合类   41220篇
现状与发展   5篇
一般理论   694篇
预防医学   139227篇
眼科学   45142篇
药学   137317篇
  8篇
中国医学   4772篇
肿瘤学   114962篇
  2021年   17244篇
  2019年   17750篇
  2018年   25069篇
  2017年   18973篇
  2016年   20759篇
  2015年   23766篇
  2014年   33285篇
  2013年   47692篇
  2012年   67323篇
  2011年   70756篇
  2010年   41486篇
  2009年   38803篇
  2008年   65354篇
  2007年   69183篇
  2006年   69361篇
  2005年   66516篇
  2004年   63994篇
  2003年   60190篇
  2002年   57955篇
  2001年   93700篇
  2000年   95072篇
  1999年   78866篇
  1998年   22175篇
  1997年   19236篇
  1996年   19094篇
  1995年   18303篇
  1994年   16660篇
  1993年   15426篇
  1992年   58442篇
  1991年   56230篇
  1990年   53815篇
  1989年   51556篇
  1988年   46879篇
  1987年   45644篇
  1986年   42906篇
  1985年   40711篇
  1984年   30236篇
  1983年   25687篇
  1982年   14870篇
  1981年   13326篇
  1979年   26044篇
  1978年   18106篇
  1977年   15383篇
  1976年   14313篇
  1975年   14900篇
  1974年   17981篇
  1973年   17256篇
  1972年   15905篇
  1971年   14644篇
  1970年   13599篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
992.
SMYTH FS  BOWEN 《Pediatrics》1948,2(1):119-131
  相似文献   
993.
Osteochondromatosis   总被引:5,自引:0,他引:5  
  相似文献   
994.
995.
996.
997.
OBJECTIVES: Local anaesthetic infiltration into the carotid sinus during carotid endarterectomy (CEA) has been recommended to minimise blood pressure fluctuations but its use remains controversial. The aim of this meta-analysis was to determine whether intra-operative administration of local anaesthetic reduces the incidence of haemodynamic instability following CEA. MATERIALS AND METHODS: A search of the Medline, Pubmed and Embase databases and the Current Controlled Trials register identified four trials, which met the pre-defined inclusion criteria for data extraction. Pooled odds ratios with 95 per cent confidence intervals (c.i.) for the development of post-operative hypotension and hypertension were calculated using a random-effects model. RESULTS: Outcomes of 432 patients were studied. Local anaesthetic blockade of the carotid sinus was associated with a pooled odds ratio of 1.25 (95 per cent c.i. 0.496 to 3.15); p=0.216) and 1.28 (95 per cent c.i. 0.699 to 2.33; p=0.428) for the development of post-operative hypotension and hypertension respectively. Although none reach significance there was a trend towards increased risk of developing a complication in those patients who received local anaesthetic. CONCLUSIONS: There are insufficient data to determine the role of intra-operative local anaesthetic administration in reducing post-operative blood pressure lability following CEA. Conversely, the possibility of harm cannot be excluded on the basis of the currently available data.  相似文献   
998.
999.
Human leukocyte antigen (HLA) compatibility has no clinically significant impact in cadaveric liver transplantation. Less is known regarding living-donor liver transplantation (LDLT). Our prior analysis of the Organ Procurement and Transplantation Network (OPTN) database suggested a higher graft failure rate in patients who underwent LDLT from donors with close HLA match. We further investigated the effect of HLA-A, -B, and -DR matching on 5-yr graft survival in adult LDLT by analyzing OPTN data regarding adult LDLT performed between 1998 and 2005. We evaluated associations between 5-yr graft survival and total, locus-specific, and haplotype match levels. Separate analyses were conducted for recipients with autoimmune (fulminant autoimmune hepatitis, cirrhosis secondary to autoimmune hepatitis, primary biliary cirrhosis, primary sclerosing cholangitis) or nonautoimmune liver disease. Multivariable Cox proportional hazard models were used to evaluate interactions and adjust for potential confounders. Among 631 patients with available donor/recipient HLA data, the degree of HLA match had no significant effect on 5-yr graft survival, even when analyzed separately in recipients with autoimmune vs. nonautoimmune liver disease. To be able to include all 1,838 adult LDLTs, we considered a first-degree related donor as substitute for a close HLA match. We found no difference in graft survival in related vs. unrelated pairs. In conclusion, our results show no detrimental impact of close HLA matching on graft survival in adult LDLT, including in recipients with underlying autoimmune liver disease.  相似文献   
1000.
Klippel-Feil syndrome (KFS) is a heterogeneous entity, characterized by specific congenital anomalies of segmentation of the cervical spine. We report a case of KFS plus atretic meningocele in one identical twin and anencephaly in the other. These identical twins were both male with no chromosome defect. One of them had anencephaly diagnosed at the gestational age of 17 weeks and died soon after birth, whereas the co-twin had KFS with multiple congenital anomalies including short neck with low hairline, occipital atretic meningocele, butterfly vertebrae, hemivertebrae, cervico-thoracic scoliosis, left thumb preaxial polydactyly, and right undescended testis. He received rehabilitation during infancy and could walk at the age of 15 months. Both of these infants had preaxial polydactyly, which is an uncommon anomaly associated with KFS. In conclusion, iniencephaly and anencephaly are probably the extreme manifestations of KFS rather than different dysraphisms. Prompt clinical suspicion with early diagnostic imaging for spine lesions and occult opening of neural tube is mandatory for further intervention and rehabilitation.  相似文献   
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