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   1414588篇
  免费   113914篇
  国内免费   3341篇
耳鼻咽喉   18412篇
儿科学   46672篇
妇产科学   41145篇
基础医学   201370篇
口腔科学   37771篇
临床医学   126491篇
内科学   285173篇
皮肤病学   33386篇
神经病学   117210篇
特种医学   53959篇
外国民族医学   465篇
外科学   211063篇
综合类   32844篇
现状与发展   3篇
一般理论   490篇
预防医学   110443篇
眼科学   31515篇
药学   98768篇
  1篇
中国医学   3347篇
肿瘤学   81315篇
  2021年   10930篇
  2019年   11734篇
  2018年   16637篇
  2017年   12734篇
  2016年   14328篇
  2015年   16076篇
  2014年   22641篇
  2013年   33525篇
  2012年   45572篇
  2011年   48105篇
  2010年   28257篇
  2009年   27150篇
  2008年   44510篇
  2007年   46989篇
  2006年   47573篇
  2005年   46032篇
  2004年   43921篇
  2003年   41845篇
  2002年   40333篇
  2001年   73126篇
  2000年   74636篇
  1999年   61676篇
  1998年   17044篇
  1997年   15468篇
  1996年   15620篇
  1995年   14822篇
  1994年   13417篇
  1993年   12604篇
  1992年   45930篇
  1991年   43554篇
  1990年   41562篇
  1989年   39616篇
  1988年   36256篇
  1987年   35432篇
  1986年   32933篇
  1985年   31344篇
  1984年   23886篇
  1983年   20069篇
  1982年   12240篇
  1981年   10808篇
  1979年   20752篇
  1978年   14604篇
  1977年   12110篇
  1976年   11397篇
  1975年   11648篇
  1974年   14016篇
  1973年   13576篇
  1972年   12667篇
  1971年   11490篇
  1970年   10937篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
OBJECTIVE: To evaluate the prenatal distribution, associated conditions and outcome of the different types of right aortic arch (RAA) detected in fetal life. METHODS: This was a retrospective review of all cases of RAA detected prenatally between 1998 and 2005 in two tertiary referral centers. RESULTS: In the study period 71 cases of RAA were detected; 26 (37%) had RAA with aberrant left subclavian artery, 23 (32%) had RAA with mirror-image branching, 20 (28%) had RAA of unknown type and two (3%) had double aortic arch. While 20/26 cases with RAA and aberrant left subclavian artery were isolated findings, all 23 cases with RAA and mirror-image branching were associated with cardiac defects, namely tetralogy of Fallot (43%) or pulmonary atresia with ventricular septal defect (22%). Of the 20 cases with RAA, 19 of unknown type were associated with heterotaxy syndromes and had additional cardiac malformations and ambiguities of the situs. The two cases with DAA were isolated findings. Seven cases in our series (10%) had a microdeletion 22q11 and these were significantly associated with extracardiac malformations. The outcome in our series depended solely on the associated cardiac and extracardiac malformations, with the exception of one infant with isolated DAA, in whom a surgical correction was warranted. CONCLUSIONS: RAA detected in fetal life is associated frequently with other cardiac/non-cardiac malformations, heterotaxy syndromes and microdeletions 22q11. The associated conditions vary depending on the branching type of the brachiocephalic vessels and the presence of extracardiac malformations.  相似文献   
92.
INTRODUCTION: Autoimmune hepatitis (AIH) is a well-defined entity in the West but there are sparse Indian data on this disease. AIM: To study the clinical profile and response to treatment of Indian patients with AIH. METHODS: This is a part retrospective and part prospective study of 50 patients (median age 48 years, range 11-82; 43 women) seen between 1995 to 2001, diagnosed to have AIH as per the revised scoring system. Clinical and laboratory profile, response to treatment, and complications of treatment were analyzed. RESULTS: AIH accounted for 6% of all patients with liver disease seen during the period. The presenting symptoms were gastrointestinal in 43 and non-gastrointestinal in 7, with median symptom duration of 6 months (range 2 weeks to 40 years). Forty patients (80%) had chronic liver disease. Associated illnesses were present in 28 patients. Twenty-six patients were classified as definite and the rest as probable AIH. Forty-nine patients had Type 1 AIH. Five patients had overlap syndrome. Forty-five patients (90%) received immunosuppressive therapy. Twelve of 18 patients receiving only prednisolone and 21 of 27 patients receiving prednisolone and azathioprine combination responded. Thirteen (26%) patients had therapy-related complications (infectious 5, non infectious 8) with two treatment-related deaths. CONCLUSION: Type 1 AIH was the predominant type of AIH. The majority of patients with AIH presented with chronic liver disease. There was good response to immunosuppressive therapy. Therapy-related complications occurred in one-fourth of patients.  相似文献   
93.
94.
95.
A new semi-empirical formula for the evaluation of (n,(3)He) reaction cross-sections at the energy of 14.6 and 20 MeV is presented. Formula was derived using the analytical expression for the evaluation of the (3)He spectrum within the frame of pre-equilibrium exciton model. The systematics obtained is compared with the empirical formula for the (n,(3)He) reaction cross-section.  相似文献   
96.
97.
98.
99.
Liposarcomas are extremely rare in the mediastinum. They may achieve considerable size before causing any symptoms. Mediastinal liposarcomas may invade surrounding structures like the pericardium or the superior vena cava. Complete surgical excision is the optimal treatment in resectable cases. Excision of adjacent structures like the pericardium may be needed if the tumor infiltrates them. We report on a case of a giant liposarcoma of the mediastinum involving both hemithoraces and extending into the neck, which was successfully managed by complete surgical excision.  相似文献   
100.
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