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   4176篇
  免费   377篇
  国内免费   21篇
耳鼻咽喉   39篇
儿科学   254篇
妇产科学   93篇
基础医学   507篇
口腔科学   165篇
临床医学   433篇
内科学   932篇
皮肤病学   53篇
神经病学   220篇
特种医学   193篇
外科学   511篇
综合类   210篇
一般理论   6篇
预防医学   389篇
眼科学   44篇
药学   230篇
中国医学   42篇
肿瘤学   253篇
  2022年   31篇
  2021年   63篇
  2020年   48篇
  2019年   60篇
  2018年   76篇
  2017年   51篇
  2016年   58篇
  2015年   80篇
  2014年   103篇
  2013年   135篇
  2012年   180篇
  2011年   177篇
  2010年   170篇
  2009年   147篇
  2008年   130篇
  2007年   188篇
  2006年   161篇
  2005年   157篇
  2004年   172篇
  2003年   119篇
  2002年   137篇
  2001年   120篇
  2000年   134篇
  1999年   133篇
  1998年   78篇
  1997年   97篇
  1996年   96篇
  1995年   66篇
  1994年   70篇
  1993年   61篇
  1992年   92篇
  1991年   65篇
  1990年   76篇
  1989年   96篇
  1988年   97篇
  1987年   84篇
  1986年   68篇
  1985年   85篇
  1984年   58篇
  1983年   47篇
  1982年   42篇
  1981年   28篇
  1980年   24篇
  1979年   49篇
  1978年   33篇
  1977年   41篇
  1976年   27篇
  1974年   23篇
  1972年   29篇
  1971年   21篇
排序方式: 共有4574条查询结果,搜索用时 218 毫秒
1.
2.
3.
The relationship of haemolytic disease of the newborn (HDN) to the transplacental passage of the four IgG subclasses was assessed at varous gestational ages by comparing the maternal and fetal IgG subclass concentrations in 34 pregnancies at risk of HDN with those in 30 pregnancies not at risk. Higher maternal and fetal IgG1 levels were attained in pregnancies at risk of HDN than in pregnancies not at risk. In contrast, a slight decrease in maternal IgG2 and IgG4 levels occurred in pregnancies at risk of HDN, as compared with a slight rise in maternal IgG2 and IgG4 levels in pregnancies not at risk of HDN. Changes in fetal IgG2 and 4 concentrations in either type of pregnancy were very similar, showing only slight increases between the 19th and 34th week of gestation. A slight decrease in maternal IgG3 occurred in both types of pregnancy. In contrast, higher and fairly steady levels of fetal IgG3 were observed in fetuses not at risk of HDN throughout gestation, when compared with those in 'at risk' pregnancies. However, the statistical reliability of these results is not clear since only small numbers of samples were tested and because wide variations in IgG concentrations were observed. The IgG subclass concentrations in 50 paired maternal and cord blood samples were also measured and revealed that IgG1 levels were substantially higher in cord rather than maternal blood; cord and maternal IgG2, 3 and 4 levels, on the other hand, were fairly similar.  相似文献   
4.
Omeprazole is a member of a new class of substituted benzimidazoles. These agents inhibit the proton pump in the gastric parietal cell, blocking the final step in the gastric acid secretory pathway. Omeprazole has been investigated for the treatment of gastric ulcer, duodenal ulcer, gastroesophageal reflux, and various hypersecretory states. The prolonged inhibition of gastric acid secretion allows for once-daily dosing in patients with peptic ulcer disease and gastroesophageal reflux, and once- or twice-daily dosing in patients with Zollinger-Ellison syndrome. Compared with currently available therapies, omeprazole is well tolerated and demonstrates a more rapid ulcer healing rate. It is superior to conventional therapies in the treatment of Zollinger-Ellison syndrome. Side effects are infrequent when the drug is used for the short-term management of ulcers.  相似文献   
5.
Defecation dynamics and behavior profiles in encopretic children   总被引:2,自引:0,他引:2  
The social competence and behavioral profiles of 38 encopretic children were evaluated, and the social competence and behavioral ratings were correlated with physiologic abnormalities found during anorectal manometric and EMG evaluation and with treatment outcome. When defecation was studied, 66% of encopretic children were not able to defecate rectal balloons and 63% were not able to relax the external anal sphincter during defecation attempts. Total social competence and behavior problem scores were not different for boys able and unable to defecate balloons. Total social competence scores were significantly lower in girls unable to defecate balloons than in those able to (P less than .006), whereas behavior problem scores were similar in girls able to and unable to defecate. We found that persistence of encopresis at 6-month and 12-month follow-up was not related to the social competence (P greater than .2) or behavioral scores (P greater than .2) but was significantly related to the inability to defecate (P less than .01) and to the inability to relax the external sphincter during defecation attempts (P less than .03).  相似文献   
6.
One hundred and one children over 1 year of age have had surgery for pelviureteric obstruction over an 11 year period. The common clinical features were abdominal pain, urinary infection or haematuria, but number presented as an incidental finding. Less commonly, the patients presented with an abdominal mass or with hypertension. The diagnosis was usually made on intravenous pyelography (IVP) but in the latter part of the series, renal nuclide scan (RNS) and ultrasonography (US) were preferred. Ninety–three patients had unilateral pyeloplasty, three had bilateral pyeloplasty and five had nephrectomy or heminephrectomy. Whereas initially nephrostomy drainage was used in the majority of patients after pyeloplasty, trend away from nephrostomy evolved in the latter part of the series. With experience, the incidence of postoperative complications was also reduced and there was reduction in the period of hospitalization. Clinical results were consistently satisfactory. Postoperative assessment after pyeloplasty was made by IVP and/or RNS and also US. A review of these investigations showed that RNS provided more factual information of the result when compared with the IVP.  相似文献   
7.
8.
Limbic kindling was examined in genetically epilepsy-prone (GEPR) and non-epileptic control rats. The early stage of kindling development was accelerated in both groups of GEPR rats compared to controls. Later stages of kindling were accelerated in GEPR-9 but not GEPR-3 rats. These results indicate that GEPR rats have an enhanced susceptibility to limbic kindling and suggest that limbic brain alterations may contribute to acceleration of the early stage kindling development in GEPR rats.  相似文献   
9.
10.
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