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   3860篇
  免费   203篇
  国内免费   15篇
耳鼻咽喉   73篇
儿科学   117篇
妇产科学   145篇
基础医学   406篇
口腔科学   100篇
临床医学   256篇
内科学   833篇
皮肤病学   72篇
神经病学   179篇
特种医学   72篇
外科学   787篇
综合类   105篇
一般理论   2篇
预防医学   284篇
眼科学   104篇
药学   323篇
中国医学   21篇
肿瘤学   199篇
  2023年   49篇
  2022年   114篇
  2021年   165篇
  2020年   103篇
  2019年   131篇
  2018年   167篇
  2017年   101篇
  2016年   127篇
  2015年   136篇
  2014年   147篇
  2013年   203篇
  2012年   329篇
  2011年   324篇
  2010年   165篇
  2009年   122篇
  2008年   198篇
  2007年   201篇
  2006年   191篇
  2005年   200篇
  2004年   160篇
  2003年   149篇
  2002年   135篇
  2001年   42篇
  2000年   33篇
  1999年   38篇
  1998年   28篇
  1997年   19篇
  1996年   9篇
  1995年   18篇
  1994年   9篇
  1993年   14篇
  1992年   11篇
  1991年   14篇
  1990年   12篇
  1989年   20篇
  1988年   16篇
  1987年   12篇
  1986年   14篇
  1985年   8篇
  1984年   13篇
  1983年   14篇
  1982年   7篇
  1981年   17篇
  1980年   13篇
  1979年   5篇
  1977年   8篇
  1976年   10篇
  1972年   6篇
  1969年   5篇
  1963年   4篇
排序方式: 共有4078条查询结果,搜索用时 15 毫秒
41.
42.
Hypertrophic cardiomyopathy (HCM) is the most common genetically transmitted cardiomyopathy. In patients resistant to medical management, myectomy is the surgical procedure of choice to reduce the symptoms of left ventricular outflow obstruction. Two‐dimensional transesophageal echocardiography (2DTEE) has become part of the operative procedure by decreasing the incidence of postoperative complications. However, because of the three‐dimensional geometry of left ventricular outflow tract, it is unable to comprehensively assess the location and severity of the obstruction and to provide accurate guidance during myectomy. In this study, 10 patients with HCM underwent live/real time three‐dimensional transesophageal echocardiography (3DTEE) intra‐operatively to measure the volume of the resected septum. This volume correlated well with the volume of the resected septal muscle directly obtained using a graduating cylinder containing water (r = 0.9, P < 0.000). 3DTEE may be potentially used as an adjunct to guide the surgeon in performing an adequate myectomy with a lower incidence of residual obstruction and complications such as an iatrogenic ventricular septal defect.  相似文献   
43.
An efflux pump inhibitor, SK-20 (5-(3,4-methylenedioxyphenyle)-4 ethyl-2E,4E-pentadienoic acid piperidide), was assessed for its toxicity at three different pharmacological profiles: acute, sub-acute and general pharmacology with pharmacokinetics. In acute study, the SK-20 was found safe up to a dose of 2000 mg/kg (b.wt.); and at sub-acute, dosages of 50 and 100 mg/kg (b.wt.) were found to be safe. However, dosages of 200 mg or above per kg (b.wt.) showed some morphological alterations in cellular architecture of both liver and kidneys in both sexes, viz., mild vascular congestion along with sporadic hemorrhages and infiltration into renal and hepatic parenchyma by mononucleate cell. General pharmacological studies did not result into any alterations in analgesic, convulsions, rectal temperatures and in the rhythm or the rate of the intestinal motility or the secretion of the bile. While the respiratory and the cardiac rate remained normal, the only parameter to show was the blood pressure, which at all the doses tested, showed a tendency toward reduction. Characteristically, the SK-20 at all doses influenced pentobarbital-induced hypnosis positively and negatively to spontaneous motor activity in a dose dependent manner. Pharmacokinetics of SK-20 revealed it to have retention time at 10.2 min and half life 2.47 h.  相似文献   
44.
45.
46.
Although with the reported versatility, vascular reliability, and easy harvesting and elevation of the gastrocnemius muscle flap, still it is used for a narrow aspect of reconstructions including only small and nearby defects. The flap is unfortunately full of limited applications, unreachable coverage, and soft tissue shortage. In this work, we are presenting 20 cases of gastrocnemius muscle flap of different etiologies, in which we applied a group of modifications to have a higher grade of applicability, more arc of rotation, and more tissue surface area. The validity of these modifications was intraoperatively tested in different defect sites and sizes to report if they are really meaningful. All flaps had survived with no complications. We have summarized these modifications in four golden rules, making these muscle flaps more versatile and more applicable. An algorithm is suggested as a leading tool for the best choice of the gastrocnemius muscle units in different situations.  相似文献   
47.
48.
49.
The goal of reconstruction of the alveolar cleft in patients with cleft lip and palate is to improve the quality of tissue, the structural stability, and increase the volume of bone. This study is a systematic review with meta-analysis of volumetric bony filling using autogenous bone and various tissue-engineered bone substitutes. We made an electronic search on MEDLINE, EMBASE, SCOPUS, WEB OF SCIENCE, “grey” publications (materials and research produced by organisations outside traditional channels for commercial or academic publishing and distribution), and relevant cross references according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Studies that reported the outcomes of volumetric grafting were included in the meta-analysis. Of 1276 studies, 26 were included in the meta-analysis. Pooled analysis of 25 studies that used autogenous bone showed a significant reduction in the volume of the cleft equivalent to 62.0% bone fill (95% CI 54.3 to 69.6), in contrast to 10 studies that used a tissue-engineered material and reported bone filling of 68.7% (95% CI 54.5 to 82.8). The estimated sizes of pooled effects across studies showed that there was no significant difference between the two major intervention groups (p value 0.901). Our statistical analysis showed that autogenous bone grafts did not differ significantly from tissue-engineered materials in their ability to fill clefts.Systematic review registration: International Prospective Register of Systematic Reviews, PROSPERO (CRD42017065045).  相似文献   
50.
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