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   861篇
  免费   106篇
  国内免费   2篇
耳鼻咽喉   36篇
儿科学   29篇
妇产科学   12篇
基础医学   83篇
口腔科学   6篇
临床医学   52篇
内科学   233篇
皮肤病学   15篇
神经病学   16篇
特种医学   21篇
外科学   118篇
综合类   18篇
预防医学   42篇
眼科学   11篇
药学   120篇
中国医学   7篇
肿瘤学   150篇
  2023年   15篇
  2022年   24篇
  2021年   54篇
  2020年   28篇
  2019年   25篇
  2018年   26篇
  2017年   40篇
  2016年   42篇
  2015年   49篇
  2014年   36篇
  2013年   61篇
  2012年   76篇
  2011年   59篇
  2010年   38篇
  2009年   25篇
  2008年   61篇
  2007年   37篇
  2006年   31篇
  2005年   27篇
  2004年   26篇
  2003年   23篇
  2002年   27篇
  2001年   8篇
  2000年   7篇
  1999年   5篇
  1998年   7篇
  1996年   5篇
  1994年   4篇
  1993年   5篇
  1992年   6篇
  1991年   9篇
  1990年   8篇
  1989年   7篇
  1988年   7篇
  1987年   6篇
  1986年   2篇
  1985年   4篇
  1984年   4篇
  1983年   3篇
  1982年   4篇
  1981年   5篇
  1980年   4篇
  1979年   2篇
  1978年   3篇
  1977年   2篇
  1976年   2篇
  1975年   2篇
  1971年   2篇
  1969年   4篇
  1966年   2篇
排序方式: 共有969条查询结果,搜索用时 359 毫秒
11.
12.
A rich collection of empirical findings accumulated over the past three decades attests to the diversity of traits that constitute the autism phenotypes. It is unclear whether subsets of these traits share any underlying causality. This lack of a cohesive conceptualization of the disorder has complicated the search for broadly effective therapies, diagnostic markers, and neural/genetic correlates. In this paper, we describe how theoretical considerations and a review of empirical data lead to the hypothesis that some salient aspects of the autism phenotype may be manifestations of an underlying impairment in predictive abilities. With compromised prediction skills, an individual with autism inhabits a seemingly “magical” world wherein events occur unexpectedly and without cause. Immersion in such a capricious environment can prove overwhelming and compromise one’s ability to effectively interact with it. If validated, this hypothesis has the potential of providing unifying insights into multiple aspects of autism, with attendant benefits for improving diagnosis and therapy.  相似文献   
13.
Background: It is generally believed that implants placed in extraction sockets have a tendency to shift in the facial direction during insertion. The purpose of this study is to investigate the effect of different thread designs on the final implant position in immediate implant placement. Methods: In a split‐mouth design involving 11 cadaver heads, each specimen received two implants, one with a square and one with a V‐shaped thread design, in maxillary incisor extraction sockets. The facio‐lingual locations of the drills and the implant were tracked, and the displacements were compared between the two groups. Results: No statistically significant differences were observed between the square and V‐shaped thread design groups. The mean displacements of the different groups showed a general tendency of the implants to be positioned facially compared with the initial drill trajectory. This tendency was greater for implants with square thread design. Conclusion: There was no significant effect of implant thread design on the positioning of implants in extraction sockets.  相似文献   
14.
15.
The results of primary coronary stenting for acute myocardial infarction (AMI) have been reported to improve significantly with the concomitant administration of platelet glycoprotein IIb/IIIa inhibitor abciximab. There are, however, no data available with the use of eptifibatide, a more cost-effective, small-molecule GP IIb/IIIa blocker with a shorter half-life. In a prospective multicenter feasibility and efficacy study, we assigned 55 consecutive patients with AMI being taken up for primary stenting to receive eptifibatide just before the procedure (two boluses of 180 microg/kg 10 min apart and a 24-hr infusion of 2 microg/kg/min). Clinical outcomes were evaluated at 30 days after the procedure. The angiographic patency of the vessel with TIMI flow rates, TIMI myocardial perfusion (TMP) grade, and corrected TIMI frame counts were assessed at the end of procedure and before hospital discharge. At 30 days, the primary endpoint, a composite of death, myocardial infarction, and urgent target vessel revascularization (TVR) was seen in 12.7% of patients. The TIMI 3 and TMP grade 3 flow, which was seen in 93% and 86% of patient, respectively, at the end of the procedure, declined to 86% and 78%, respectively (P < 0.05) before hospital discharge. Corrected TIMI frame counts also decreased from 25.7 +/- 7.2 to 22.9 +/- 6.8 (P < 0.05). There were five (9.1%) instances of subacute thrombosis (SAT) presenting as AMI, needing urgent TVR in all, within 3-5 days of the primary procedure. No excessive bleeding complication, directly attributable to the use of eptifibatide, was observed. The study was terminated prematurely because of an unacceptable SAT rate. Administration of eptifibatide along with primary stenting for AMI is associated with a high TIMI 3 and TMP grade 3 flow acutely. However, these flows decline significantly before hospital discharge and lead to a high rate of SAT. The dosage and duration of infusion of eptifibatide in this setting needs further evaluation.  相似文献   
16.
X-linked agammaglobulinemia (XLA) is a hereditary defect of B-cell differentiation in man caused by deficiency of Bruton tyrosine kinase (BTK). A three-dimensional model for the BTK kinase domain, based on the core structure of cAMP-dependent protein kinase, was used to interpret the structural basis for disease in eight independent point mutations in patients with XLA. As Arg-525 of BTK has been thought to functionally substitute for a critical lysine residue in protein-serine kinases, the mutation Arg-525-->Gln was studied and found to abrogate the tyrosine kinase activity of BTK. All of the eight mutations (Lys-430-->Glu, Arg-520-->Glu, Arg-525-->Gln, Arg-562-->Pro, Ala-582-->Val, Glu-589-->Gly, Gly-594-->Glu, and Gly-613-->Asp) were located on one face of the BTK kinase domain, indicating structural clustering of functionally important residues.  相似文献   
17.
18.
We identified and characterized enteroviruses associated with aseptic meningitis in children between April 2009 and March 2010. Enterovirus RNA was detected in 51 (45.5 %) of 112 CSF samples. Molecular typing by RT-PCR and sequencing of a partial VP1 region revealed the predominance of echovirus (ECV) 32 (n = 20), followed by ECV 11 (n = 10), ECV 13 and ECV 14 (n = 5 each), coxsackievirus (CV) B3 and CV B6 (n = 3 each), CV A2, CV A10 and ECV 30 (n = 1 each). Phylogenetic analysis of ECV 32 showed 0 to 4 % sequence divergence among strains of the present study and 20-23 % from the prototype Puerto Rico strain at the nucleotide level. This is the first report of ECV 32 associated with an aseptic meningitis epidemic and identification of seven different enterovirus serotypes (CV A2, CV A10, CV B3, CV B6, ECV 13, ECV 14 and ECV 32) in meningitis cases from India.  相似文献   
19.
Soft-tissue defects of the little finger are challenging especially when bone, tendon or vascular pedicle is exposed because of trauma. The hypothenar island flap is easy to harvest and has a good colour and texture match to the little finger pulp. We present nine clinical cases of soft tissue defects of the little finger covered using the reversed hypothenar fasciocutaneous island flap. This article intends to highlight the ease of elevation and good clinical results of the hypothenar flap which is rarely used.KEY WORDS: Hypothenar island flap, island flap, soft-tissue defects of the little finger  相似文献   
20.
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