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   556篇
  免费   19篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   29篇
妇产科学   2篇
基础医学   61篇
口腔科学   11篇
临床医学   21篇
内科学   105篇
皮肤病学   8篇
神经病学   9篇
特种医学   82篇
外科学   53篇
综合类   123篇
预防医学   19篇
眼科学   3篇
药学   14篇
肿瘤学   33篇
  2021年   27篇
  2020年   1篇
  2019年   7篇
  2018年   5篇
  2017年   4篇
  2016年   5篇
  2015年   12篇
  2014年   8篇
  2013年   8篇
  2012年   9篇
  2011年   9篇
  2010年   25篇
  2009年   21篇
  2008年   21篇
  2007年   15篇
  2006年   23篇
  2005年   14篇
  2004年   18篇
  2003年   12篇
  2002年   10篇
  2001年   9篇
  2000年   9篇
  1999年   14篇
  1998年   32篇
  1997年   25篇
  1996年   28篇
  1995年   16篇
  1994年   31篇
  1993年   10篇
  1992年   6篇
  1991年   2篇
  1990年   7篇
  1989年   13篇
  1988年   14篇
  1987年   16篇
  1986年   15篇
  1985年   13篇
  1984年   9篇
  1983年   8篇
  1982年   6篇
  1981年   8篇
  1980年   8篇
  1979年   3篇
  1978年   3篇
  1977年   5篇
  1976年   4篇
  1975年   4篇
  1972年   1篇
  1969年   1篇
  1961年   1篇
排序方式: 共有577条查询结果,搜索用时 15 毫秒
61.
62.
The Thy-l.1 molecule was isolated from the BW5147 murine lymphoblastoid cell line. The initial step in purification was the preparation of a crude plasma membrane fraction followed by acetone precipitation. The acetone pellet was solubilized using deoxycholate (DOC) and Thy-1.1 was purified by use of a Lens culinaris lectin affinity column and an AcA-34 gel filtration column. The purified glycoprotein with Thy-1.1 activity had a mol wt of approximately 25,000 daltons. The isolation of this molecule was effected by detecting Thy-I activity utilizing rabbit anti- mouse brain serum tested on rat thymocytes. Congenic anti-Thy-l.1 serum was ineffective in detecting Thy-l.1 after DOC solubilization. An antiserum prepared in rabbits to the purified Thy-1.1 was found to be cytotoxic to mouse and rat thymocytes. The cytotoxic activity of this antisera could be completely absorbed with AKR/Jax brain and thymus but was not absorbed by liver. In addition, AKR/Jax thymocytes totally absorbed all cytotoxic activity of the rabbit anti-purified Thy-1 serum for BW5147 cells suggesting that the cell line shares identical specificities with normal thymocytes. The purified Thy-1.1 molecule was able to totally absorb the cytotoxic activity of mouse congenic anti-Thy-1. These studies serve as a model for the isolation of other murine lymphoid cell surface components in quantities for detailed structural and functional analysis.  相似文献   
63.
64.
65.
The recent increase in the incidence of ectopic pregnancies was associated with rapid improvement in the diagnostic and therapeutic techniques. Quantitative serum B-HCG radioimmunoassay and high resolution vaginal ultrasonography have facilitated early diagnosis of ectopic pregnancy allowing a more conservative approach to patient management. Different conservative surgical and medical lines of management recently developed were associated with and increased chance of subsequent intrauterine pregnancy with no increase in the incidence of repeat ectopic pregnancy. Outpatient systemic medical treatment seems to be a preferred alternative to conservative surgery. In selected cases, it is associated with a lower complication rate and promising result for fertility. (Br J Clin Pract 1996; 50(7) : 376-380.)  相似文献   
66.
复合富血小板血浆的酶处理异种骨修复兔桡骨缺损   总被引:1,自引:4,他引:1  
目的:自源性的富血小板血浆可促进骨组织及软组织的修复,又不存在疾病传播及免疫排斥的可能。实验拟验证应用复合富血小板血浆的酶处理异种骨修复节段性骨缺损的可行性。方法:实验于2006-07/12在解放军昆明总医院实验动物中心完成。①实验分组:选用新西兰大耳白兔20只,体质量2.0~2.5kg,共40只前肢,随机分为复合酶组,单纯酶组,脱蛋白骨组,空白组。每组共10个标本。②实验方法:制作富血小板血浆及酶处理的异种骨并制备桡骨中段15mm的节段性骨缺损模型,将上述骨材料植入兔桡骨缺损处,其中复合酶组:植入复合富血小板血浆的酶处理异种骨;单纯酶组:植入酶处理异种骨;脱蛋白骨组:植入部分脱蛋白骨;空白组:不植入任何材料。③实验评估:分别于术后4,8,12周取材,X线片及苏木精-伊红染色分别观察骨缺损区的新骨形成情况。同时对各组骨密度进行测定。结果:纳入新西兰大耳白兔20只,均进入结果分析,所有手术无术后感染,无动物死亡,植入骨无脱落。①所有动物麻醉苏醒后均恢复进食,2周伤口愈合,未出现感染及渗液等。富血小板血浆中的血小板含量均为全血的4倍以上。②在同一时间点,酶处理后异种骨与部分脱蛋白骨在成骨能力方面差异无显著性意义,而复合富血小板血浆的酶处理异种骨在8周时骨缺损部分修复;12周时完全修复。空白组骨缺损未修复。③8,12周时复合酶组骨密度较单纯酶组、脱蛋白骨组高,差异有显著性意义(P<0.05);单纯酶组与脱蛋白骨组比较无明显差异(P>0.05)。结论:经酶处理后异种骨可用于节段性骨缺损的修复,复合富血小板血浆后有明显加速骨愈合的作用。  相似文献   
67.
68.

Background

The incidence of hepatitis-A among adults in India is on the decline as majority develops protective immunity to it by late adolescence. Most of these studies are from northern India. Clinical spectrum of sporadic acute viral hepatitis from southern India has not been well documented.

Methods

A prospective hospital based study was conducted in a large military hospital in southern India. 224 consecutive patients with acute viral hepatitis were studied for their presentation, etiology and clinical features.

Result

Hepatitis-E was detected in 102 (45.4%), hepatitis A in 74 (33%) and hepatitis B in 28 (12.5%) patients. Acute hepatitis C was detected in two patients. 15 patients had a mixed infection. Hepatitis A constituted 41.2% and 31.3% of all cases in the age groups 11-20 and 21-30 years respectively. Cholestasis was present in 68 (30.4%) patients with hepatitis E accounting for most (61.8%) cases. There were four (1.8%) cases of acute liver failure. Two cases were due to hepatitis E and one case each was due to hepatitis A and hepatitis B. A relapsing course was seen in four cases due to hepatitis-A.

Conclusion

Hepatitis A remains a significant cause of sporadic acute viral hepatitis in young adults in southern India.Key Words: Viral hepatitis, Hepatitis A  相似文献   
69.

Background

Obesity is associated with increased cardiovascular morbidity and mortality. A direct effect of isolated obesity on cardiac function is not well established. The study was designed to determine the direct effect of various grades of isolated obesity on echocardiographic indices of systolic and diastolic left ventricular function.

Methods

Fifty one obese and 25 normal weight, serving personnel without any other pathological condition were studied. Group I (n=25) consisted of subjects with normal weight and body mass index (BMI <25kg/m2), Group II (n=34) of overweight subjects (BMI 25-29.9 kg/m2) and Group III (n=17) of obese subjects (BMI >30 kg/m2). Echocardiographic indices of systolic and diastolic function were obtained and dysfunction was assumed when at least two values differed by ≥ 2 SD from the normal weight group.

Result

Ejection fraction, fractional shortening were increased (p<0.05) in Group II and III. Left ventricular dimensions were increased (p< 0.001) but relative wall thickness was unchanged. Systolic dysfunction was not observed in any of the obese patients. The mitral valve pressure half time (p< 0.01), left atrial diameter (p < 0.01) and the deceleration time were increased (p< 0.01) in obese subjects, while other diastolic variables were unchanged. No difference were found between obesity subgroups. Subclinical diastolic dysfunction was more prevalent among obese subjects. BMI correlated significantly with indices of left ventricular systolic and diastolic function.

Conclusion

Subclinical left ventricular diastolic dysfunction was noted in all grades of obesity which correlates with BMI.Key Words: Obesity, Systolic function, Diastolic function, Echocardiography  相似文献   
70.
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