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   831篇
  免费   46篇
  国内免费   36篇
耳鼻咽喉   5篇
儿科学   69篇
妇产科学   3篇
基础医学   80篇
口腔科学   36篇
临床医学   107篇
内科学   178篇
皮肤病学   23篇
神经病学   18篇
特种医学   184篇
外科学   40篇
综合类   24篇
预防医学   43篇
眼科学   14篇
药学   50篇
中国医学   1篇
肿瘤学   38篇
  2023年   3篇
  2022年   5篇
  2021年   10篇
  2020年   6篇
  2019年   12篇
  2018年   17篇
  2017年   12篇
  2016年   11篇
  2015年   22篇
  2014年   13篇
  2013年   27篇
  2012年   19篇
  2011年   15篇
  2010年   41篇
  2009年   38篇
  2008年   15篇
  2007年   24篇
  2006年   19篇
  2005年   38篇
  2004年   15篇
  2003年   4篇
  2002年   9篇
  2001年   15篇
  2000年   12篇
  1999年   18篇
  1998年   47篇
  1997年   48篇
  1996年   48篇
  1995年   33篇
  1994年   40篇
  1993年   36篇
  1992年   12篇
  1991年   14篇
  1990年   7篇
  1989年   22篇
  1988年   43篇
  1987年   19篇
  1986年   17篇
  1985年   31篇
  1984年   9篇
  1983年   3篇
  1982年   6篇
  1981年   8篇
  1980年   8篇
  1979年   6篇
  1978年   6篇
  1977年   7篇
  1976年   12篇
  1975年   4篇
  1968年   2篇
排序方式: 共有913条查询结果,搜索用时 15 毫秒
111.
112.
A substudy of a phase I/II, prospective, multicenter clinical trial was carried out to investigate the potential benefit of therapeutic vaccination on hepatitis B e antigen-negative patients with chronic hepatitis B (CHB), treated efficiently with analogues. Patients were randomized in 2 arms, one receiving a hepatitis B virus (HBV) envelope DNA vaccine, and one without vaccination. At baseline, HBV-specific interferon (IFN)-γ–producing T cells were detected in both groups after in vitro expansion of peripheral blood mononuclear cells. Vaccine-specific responses remained stable in the vaccine group, whereas in the control group the percentage of patients with HBV-specific IFN-γ–producing T cells decreased over time. The vaccine-specific cytokine-producing T cells were mostly polyfunctional CD4+ T cells, and the proportion of triple cytokine-producer T cells was boosted after DNA injections. However, these T-cell responses did not impact on HBV reactivation after stopping analogue treatment. Importantly, before cessation of treatment serum hepatitis B surface antigen (HBsAg) titers were significantly associated with DNA or HBsAg clearance. Therapeutic vaccination in CHB patients with persistent suppression of HBV replication led to the persistence of T-cell responses, but further improvements should be searched for to control infection after treatment discontinuation.  相似文献   
113.
114.
115.
Dore  M; Burns  AR; Hughes  BJ; Entman  ML; Smith  CW 《Blood》1996,87(5):2029-2037
Adhesion between platelets and neutrophils is mediated through the interaction of P-selectin on activated platelets with a carbohydrate- containing structure on neutrophils, and occurs under both static and shear conditions. Recent studies using flow chambers have shown that neutrophils become activated after binding to surface-adherent platelets expressing P-selectin. The objective of the present study was to investigate the effect of such activation on the interactions of platelet P-selectin with its ligand on neutrophils. Flow cytometric analyses using P-selectin chimeras revealed that activation induced a rapid and marked reduction in chimera binding, with levels of binding decreased by 71% after 15 minutes of stimulation with the chemotactic agent, FMLP. Using a visual assay of platelet-neutrophil rosetting, we showed that the P-selectin ligand was translocated and clustered at the uropod of neutrophils following the shape changes and polarization induced by chemotactic stimulation. Activated neutrophils bound to surface-adherent platelets also displayed the clustering of P-selectin ligand at the uropod, and these neutrophils detached from the platelets when a shear stress (2 dynes/cm2) was applied through the adhesion chamber. These results indicate that chemotactic stimulation of neutrophils induces changes in the surface expression and distribution of a biologically relevant ligand for P-selectin, and that these changes might influence the adhesive interactions occurring between neutrophils and activated platelets.  相似文献   
116.
117.
Antibody to the recently identified hepatitis C virus (HCV) was investigated in sera of 50 leukemic children who had chronic liver disease (CLD), observed for 1 to 12.6 years after therapy withdrawal. All patients were tested for anti-HCV at regular intervals: Ortho- enzyme-linked immunosorbent assay (ELISA) test was performed in all cases. Reactive sera were also tested by recombinant immunoblotting assay to define the specificity of the results obtained by ELISA. Twelve cases (24%) were persistently positive (group A), 11 (22%) were transiently anti-HCV+ positive (group B), and 27 (54%) were negative. Mean SGPT peak during follow-up was significantly higher in group A (P = .014, A v B and P less than .00001, A v C). SGPT normalized off- therapy in 1 of 12 cases (group A), 10 of 11 (group B), and 19 of 27 (group C) (P = .0004, A v B and P = .012, A v C). Accordingly, liver histology, available in 37 patients, showed signs of chronic hepatitis in all patients in group A while most patients in group B and C had less severe liver lesions. These results indicate that HCV plays a significant role in the etiology of chronic hepatitis in leukemic patients and that persistent anti-HCV activity correlates with a more severe CLD, which could jeopardize the final prognosis of children cured of leukemia.  相似文献   
118.
119.
BACKGROUND AND AIM: While lispro insulin has been reported to lower postprandial blood glucose concentrations, less consistent effects have been shown for glycosylated hemoglobin (HbA1c) levels. Aim of this study was to determine whether pre-meal association of NPH, an intermediate-acting insulin, with lispro improves overall glycemic control in type 1 diabetic patients. METHODS AND RESULTS: Eighty-five type 1 diabetic patients were studied in a multicenter randomized comparative (human regular vs lispro insulin) crossover (3-month) study in which NPH insulin was given as a dinner or bedtime injection and at breakfast and lunch if necessary. The number of injections was kept constant: 42% and 58% of patients injected insulin 3 and 4 times per day, respectively. Fasting and preprandial blood glucose levels were similar, while postprandial levels improved after lispro compared to human regular insulin (breakfast: 8.28 +/- 2.39 vs 9.28 +/- 2.72 mmol/l; lunch: 8.33 +/- 2.67 vs 9.06 +/- 2.67 mmol/l, dinner: 8.06 +/- 2.72 vs 9.28 +/- 2.44 mmol/l, ANOVA: p = 0.003). HbA1c also improved after lispro: 8.1 +/- 0.9 vs 8.3 +/- 0.8%, p < 0.05. The rate of hypoglycemia was similar. Patients showed better acceptance of lispro treatment (p < 0.001). CONCLUSIONS: Lispro improves overall blood glucose control in type 1 diabetic patients without increasing the incidence of hypoglycemia. This can be achieved by an optimal combination of lispro insulin with NPH whenever the time intervals between meals are too long.  相似文献   
120.
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