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   10786篇
  免费   742篇
  国内免费   72篇
耳鼻咽喉   69篇
儿科学   234篇
妇产科学   232篇
基础医学   1318篇
口腔科学   266篇
临床医学   1023篇
内科学   2576篇
皮肤病学   138篇
神经病学   1091篇
特种医学   594篇
外科学   1239篇
综合类   305篇
一般理论   9篇
预防医学   920篇
眼科学   315篇
药学   735篇
  3篇
中国医学   40篇
肿瘤学   493篇
  2023年   65篇
  2022年   105篇
  2021年   209篇
  2020年   137篇
  2019年   165篇
  2018年   194篇
  2017年   129篇
  2016年   164篇
  2015年   177篇
  2014年   243篇
  2013年   434篇
  2012年   518篇
  2011年   584篇
  2010年   386篇
  2009年   406篇
  2008年   522篇
  2007年   581篇
  2006年   559篇
  2005年   585篇
  2004年   486篇
  2003年   453篇
  2002年   456篇
  2001年   228篇
  2000年   215篇
  1999年   206篇
  1998年   207篇
  1997年   163篇
  1996年   148篇
  1995年   136篇
  1994年   97篇
  1993年   112篇
  1992年   133篇
  1991年   129篇
  1990年   107篇
  1989年   111篇
  1988年   118篇
  1987年   104篇
  1986年   97篇
  1985年   101篇
  1984年   69篇
  1983年   88篇
  1982年   78篇
  1981年   77篇
  1980年   69篇
  1979年   57篇
  1978年   71篇
  1977年   68篇
  1976年   53篇
  1975年   50篇
  1973年   48篇
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
1.
2.
3.
4.
5.
The results of lumbar fusion in chronic low back pain (LBP) patients vary considerably, and there is a need for proper patient selection. Lumbosacral orthoses have been widely used to predict outcome, however, with little scientific support. The aim of the present study was to determine the value of a pantaloon cast test in selecting chronic LBP patients for lumbar fusion or conservative management. First, a systematic review of the literature was carried out in which two independent reviewers identified studies in Medline, Cochrane and Current Contents databases. Three papers met the selection criteria. In the only study with a control group, a significantly better outcome after fusion compared to conservative treatment was found in patients who reported significant pain relief while in a cast (i.e. a positive cast test). The results of lumbar fusion, however, were not significantly different for patients with a positive and those with a negative cast test. In addition to the review, a clinical cohort study of 257 LBP patients, who had been allocated to either lumbar fusion or conservative management by a temporary external transpedicular fixation trial, was performed. Prior to allocation, all had undergone a pantaloon cast test. Patients with no history of prior spine surgery and with a positive pantaloon cast test had a better outcome after lumbar fusion than those treated conservatively (P = 0.002, χ 2 test). In patients with previous spine operations the outcomes were poor and the test was of no value. From the literature and the present patient cohort, it was concluded that only in chronic LBP patients without prior spine surgery, a pantaloon cast test with substantial pain relief suggests a favorable outcome of lumbar fusion compared to conservative management. The test has no value in patients who have had previous spine surgery.  相似文献   
6.
Background Beating heart surgery has now become the commonest technique of doing Coronary Artery Bypass Graft Surgery (CABG) in our country. It is being used even in such high risk situations like diffuse coronary disease and Critical Left Main stem Stenosis (LMCS) with good results. The aim of this study is to retrospectively review our results in Off-Pump Coronary Artery Bypass Surgery (OPCAB) in patients with critical left main stem stenosis. Methods This study is a retrospective analysis of the data of patients who underwent primary coronary artery bypass surgery. During the period from April 2003 to September 2005 a total of 64 patients underwent OPCAB procedure for critical LMCS. During the same period 10 patients underwent CABG on Cardio Pulmonary Bypass (CPB). The age range was 36–77yrs. The sex distribution was M: F 53∶10. Ten patients were done as emergency. 2 of them were on Intra Aortic Balloon Pump (IABP) support preoperatively. 10 patients were high risk with a Euro score of ≥5. Results Left Internal Mammary Artery (LIMA) was used in 78% of cases. Average grafts per patient was 2.96. The median ventilation time was 5.91 hrs. New IABP insertion in postoperative period was required in 1 patient. One patient was reexplored for bleeding. There was one perioperative myocardial infarction. 57% of patients did not need any blood transfusion. There was no conversion to CPB. There was no operative mortality. Inotropes were used in ten cases. Conclusions OPCAB is a safe method of revascularization in patients with critical LMCS. Preoperative IABP is useful in patients with cardiogenic shock. However, there is a place for CPB in patients needing additional procedures like Mitral Valve repair (MV repair) or Dor's procedure or when the vessels are very diffusely diseased. Those patients who are unstable despite IABP support may be managed by Beating heart On Pump (BHOP) technique.  相似文献   
7.
Protein-calorie malnutrition (PCM) impairs immune responsiveness predisposing to Candida albicans sepsis, but mechanisms are unclear. This study examined the effect of PCM on enteric-derived C. albicans intestinal translocation and the ability of in vivo interferon-gamma (IFN-gamma) to upregulate macrophage (MO) candidacidal mechanisms in PCM mice. Control (24% casein) and low protein (2.5%) diets were given for 4 weeks. Mice (n = 160) were fed C. albicans in their drinking water for 3 days and C. albicans translocation (mean colony-forming units (CFU)/g tissue +/- SEM) to the GI tract, liver, spleen, and kidney was assessed at 1 and 5 days following endotoxin challenge of 1, 5, and 10 mg/kg body wt. In a separate study (n = 100 mice), IFN-gamma (1000-10,000 U/day ip) vs saline was given for 3 days prior to harvesting peritoneal macrophages for assay of superoxide anion (O2-), percentage macrophage phagocytosis of C. albicans, and percentage killing of C. albicans. On Day 1, fungal translocation to the intestinal wall and systemic organs in the PCM group was significantly higher. On Day 5, mean CFU were significantly higher in the PCM group, indicating impaired organ clearance. Mean O2-, phagocytosis, and killing were significantly impaired in the PCM group (P less than 0.05), but IFN-gamma improved all functions. PCM significantly depressed host responses to C. albicans. IFN-gamma treatment enhanced candidacidal mechanisms, suggesting a therapeutic role in the malnourished host predisposed to C. albicans sepsis.  相似文献   
8.
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