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   1024篇
  免费   48篇
  国内免费   90篇
耳鼻咽喉   2篇
儿科学   77篇
妇产科学   13篇
基础医学   127篇
口腔科学   21篇
临床医学   218篇
内科学   224篇
皮肤病学   77篇
神经病学   26篇
特种医学   76篇
外科学   90篇
综合类   65篇
预防医学   34篇
眼科学   8篇
药学   73篇
中国医学   3篇
肿瘤学   28篇
  2017年   12篇
  2016年   9篇
  2015年   12篇
  2014年   24篇
  2013年   29篇
  2012年   12篇
  2011年   12篇
  2010年   33篇
  2009年   23篇
  2008年   11篇
  2007年   62篇
  2006年   15篇
  2005年   24篇
  2004年   15篇
  2003年   22篇
  2002年   17篇
  2001年   28篇
  2000年   20篇
  1999年   21篇
  1998年   37篇
  1997年   51篇
  1996年   36篇
  1995年   40篇
  1994年   36篇
  1993年   30篇
  1992年   19篇
  1991年   12篇
  1990年   24篇
  1989年   37篇
  1988年   26篇
  1987年   18篇
  1986年   21篇
  1985年   14篇
  1984年   11篇
  1983年   12篇
  1982年   11篇
  1981年   13篇
  1979年   8篇
  1978年   8篇
  1977年   15篇
  1976年   13篇
  1975年   10篇
  1974年   8篇
  1971年   8篇
  1968年   9篇
  1966年   9篇
  1965年   12篇
  1963年   11篇
  1959年   13篇
  1956年   8篇
排序方式: 共有1162条查询结果,搜索用时 0 毫秒
71.
72.
73.

Background  

Stress urinary incontinence is a common condition affecting approximately 20% of adult women causing substantial individual (quality of life) and economic (119 million Euro/year spent on incontinence pads in the Netherlands) burden. Pelvic floor muscle training (PFMT) is regarded as first line treatment, but only 15-25% of women will be completely cured. Approximately 65% will report that their condition improved, but long term adherence to treatment is problematic. In addition, at longer term (2-15 years) follow-up 30-50% of patients will end up having surgery. From 1996 a minimal invasive surgical procedure, the Tension-free Vaginal Tape (TVT) has rapidly become the gold standard in surgical treatment of stress urinary incontinence. With TVT 65-95% of women are cured. However, approximately 3-6% of women will develop symptoms of an overactive bladder, resulting in reduced quality of life. Because of its efficacy the TVT appears to be preferable over PFMT but both treatments and their costs have not been compared head-to-head in a randomised clinical trial.  相似文献   
74.
To test the ability of Gianturco expandable metallic stents to dilate and maintain patency in stenotic venae cavae, stenosis of the inferior vena cava was created in seven mongrel dogs by the percutaneous injection of absolute ethanol into the paravascular retroperitoneal space. Gianturco stents, placed across the stenotic segment, resulted in successful dilatation with improved hemodynamics in four dogs. The stents failed to dilate an occluded vena cava in one dog; in the remaining dogs, stent placement was complicated by early migration and occlusion. Gianturco stents were placed in two patients, one with superior vena cava syndrome and one with retroperitoneal fibrosis that obstructed the inferior vena cava, and resulted in immediate relief of presenting symptoms. These results should be viewed cautiously, but further investigation into the clinical use of the stents is indicated, especially for patients for whom other treatments are difficult.  相似文献   
75.
76.
自国产沉香(Aquilaria sinensis)[瑞香科(Thymeleaceae)植物]的挥发油中,经硅胶柱层析和离心薄层层析分离得到一新的倍半萜,命名为异白木香醇(isobaimuxinol),根据光谱(IR,1HNMR,13CNMR,2 D-NMR和MS)分析确定其结构式为(Ⅰ)所示,并用X-光衍射晶体解析进一步确定了其立体化学。同时,也从该植物挥发油的低沸点部分分离得到四个已知化合物:苄基丙酮,对甲氧基苄基丙酮,茴香酸和β-沉香呋喃。这些化合物均为首次从该植物中得到。  相似文献   
77.
ABSTRACT— Glafenine was associated with hepatic injury in 38 cases. The causal relationship was assessed on the basis of the temporal relationship with drug use, course and exclusion of other causes. In 27 cases a causal relationship was considered likely, i.e. ‘probable’ (12 cases) or ‘possible’ (15 cases), whereas in 11 cases it was either unlikely or unclassifiable. In both the ‘probable’ and ‘possible’ groups 60–70% of individuals were women. Jaundice was present in three-quarters of cases in both groups. Eosinophilia was more frequent in the group of ‘probable’ cases, and this group had the highest case-fatality rate (42%). Onset varied from 2 days (after a rechallenge) to 8 months, but most cases appeared between 2 weeks and 4 months after starting therapy. Histology in 22 cases showed a predominantly hepatocellular pattern, varying from spotty panlobular necrosis, centrilobular and (sub)massive necrosis (acute pattern) to fibrosis and cirrhosis (chronic pattern). The chemical structure of glafenine and the clinicopathological pattern it induces resemble that of cinchophen. The incidence is unknown. Either metabolic idiosyncrasy or an immunoallergic mechanism seems to be responsible.  相似文献   
78.
Children with sickle cell anemia have an increased susceptibility to bacterial infections, especially to those caused by Streptococcus pneumoniae. We therefore conducted a multicenter, randomized, double-blind, placebo-controlled clinical trial to test whether the regular, daily administration of oral penicillin would reduce the incidence of documented septicemia due to S.pneumoniae in children with sickle cell anemia who were under the age of three years at the time of entry. The children were randomly assigned to receive either 125 mg of penicillin V potassium (105 children) or placebo (110 children) twice daily. The trial was terminated 8 months early, after an average of 15 months of follow-up, when an 84 percent reduction in the incidence of infection was observed in the group treated with penicillin, as compared with the group given placebo (13 of 110 patients vs. 2 of 105; P = 0.0025), with no deaths from pneumococcal septicemia occurring in the penicillin group but three deaths from the infection occurring in the placebo group. On the basis of these results, we conclude that children should be screened in the neonatal period for sickle cell hemoglobinopathy and that those with sickle cell anemia should receive prophylactic therapy with oral penicillin by four months of age to decrease the morbidity and mortality associated with pneumococcal septicemia.  相似文献   
79.
80.
自国产沉香(Aquilaria sinensis)[瑞香科(Thymeleaceae)植物]的挥发油中,经硅胶柱层析和离心薄层层析分离得到一新的倍半萜,命名为异白木香醇(isobaimuxinol),根据光谱(IR,~1HNMR,~(13)CNMR,2 D-NMR和MS)分析确定其结构式为(Ⅰ)所示,并用X-光衍射晶体解析进一步确定了其立体化学。同时,也从该植物挥发油的低沸点部分分离得到四个已知化合物:苄基丙酮,对甲氧基苄基丙酮,茴香酸和β-沉香呋喃。这些化合物均为首次从该植物中得到。  相似文献   
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