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   688篇
  免费   61篇
  国内免费   3篇
耳鼻咽喉   3篇
儿科学   41篇
妇产科学   6篇
基础医学   94篇
口腔科学   18篇
临床医学   124篇
内科学   182篇
皮肤病学   14篇
神经病学   7篇
特种医学   71篇
外科学   29篇
综合类   26篇
一般理论   2篇
预防医学   39篇
眼科学   1篇
药学   45篇
肿瘤学   50篇
  2022年   3篇
  2021年   6篇
  2019年   6篇
  2018年   13篇
  2017年   7篇
  2016年   9篇
  2015年   8篇
  2014年   13篇
  2013年   19篇
  2012年   25篇
  2011年   29篇
  2010年   17篇
  2009年   30篇
  2008年   34篇
  2007年   30篇
  2006年   37篇
  2005年   34篇
  2004年   30篇
  2003年   28篇
  2002年   22篇
  2001年   18篇
  2000年   29篇
  1999年   17篇
  1998年   21篇
  1997年   30篇
  1996年   20篇
  1995年   15篇
  1994年   8篇
  1993年   10篇
  1992年   15篇
  1991年   6篇
  1990年   7篇
  1989年   15篇
  1988年   8篇
  1987年   13篇
  1986年   11篇
  1985年   27篇
  1984年   10篇
  1983年   9篇
  1982年   12篇
  1981年   9篇
  1980年   8篇
  1979年   5篇
  1978年   6篇
  1977年   4篇
  1976年   2篇
  1975年   5篇
  1973年   2篇
  1972年   3篇
  1891年   1篇
排序方式: 共有752条查询结果,搜索用时 0 毫秒
71.
The induction of tumor-protective immunity against malignancies remains a major challenge in cancer immunotherapy. A novel, humanized anti-ganglioside-GD(2)-IL-2 immunocytokine (hu14.18-IL-2) induced CD8(+) T cells to eradicate established pulmonary metastases of B78-D14 murine melanoma, in a process that required help by CD4(+) T cells and was mediated by the CD40/CD40 ligand (CD40L) interaction. The anti-tumor effect was diminished in mice deficient in CD4(+) T-cells. Three lines of evidence show that CD4(+) T-cell help was mediated by CD40/CD40L interaction but not by endogenous IL-2 production. First, the hu14.18-IL-2-induced anti-tumor response is partially abrogated in C57BL/6J CD40L knockout (KO) mice in contrast to C57BL/6J IL-2 KO animals, in which the immunocytokine was completely effective. Second, partial abrogation of the anti-tumor effect is induced with anti-CD40L antibodies to the same extent as with CD4(+) T-cell depletion. Third, a complete anti-tumor response induced by hu14.18-IL-2 can be reconstituted in C57BL/6J CD40L KO mice by simultaneous stimulation with an anti-CD40 mAb. These results suggest that help provided by CD4(+) T cells via CD40/CD40L interactions in our tumor model is crucial for effective immunotherapy with an IL-2 immunocytokine.  相似文献   
72.
73.
The major advantage of hydroxyapatite (HA)‐forming calcium phosphate cements (CPCs) used as bone replacement materials is their setting under physiological conditions without the necessity for thermal treatment that allows the incorporation of biological factors. In the present study, we have combined the biocompatible consolidation of CPCs with the potential of rapid prototyping (RP) techniques to generate calcium phosphate‐based scaffolds with defined inner and outer morphology. We demonstrate the application of the RP technique three‐dimensional (3D) plotting for the fabrication of HA cement scaffolds. This was realized by utilizing a paste‐like CPC (P‐CPC) which is stable as a malleable paste and whose setting reaction is initiated only after contact with aqueous solutions. The P‐CPC showed good processability in the 3D plotting process and allowed the fabrication of stable 3D structures of different geometries with adequate mechanical stability and compressive strength. The cytocompatibility of the plotted P‐CPC scaffolds was demonstrated in a cell culture experiment with human mesenchymal stem cells. The mild conditions during 3D plotting and post‐processing and the realization of the whole procedure under sterile conditions make this approach highly attractive for fabrication of individualized implants with respect to patient‐specific requirements by simultaneous plotting of biological components. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   
74.
Objective: For many patients with type 2 diabetes, oral antidiabetic agents (OADs) do not provide optimal glycaemic control, necessitating insulin therapy. Fear of hypoglycaemia is a major barrier to initiating insulin therapy. The AT.LANTUS study investigated optimal methods to initiate and maintain insulin glargine (LANTUS®, glargine, Sanofi-aventis, Paris, France) therapy using two treatment algorithms. This subgroup analysis investigated the initiation of once-daily glargine therapy in patients suboptimally controlled on multiple OADs. Research Design and Methods: This study was a 24-week, multinational (59 countries), multicenter (611), randomized study. Algorithm 1 was a clinic-driven titration and algorithm 2 was a patient-driven titration. Titration was based on target fasting blood glucose ≤100 mg/dl (≤5.5 mmol/l). Algorithms were compared for incidence of severe hypoglycaemia [requiring assistance and blood glucose <50 mg/dl (<2.8 mmol/l)] and baseline to end-point change in haemoglobin A1c (HbA1c). Results: Of the 4961 patients enrolled in the study, 865 were included in this subgroup analysis: 340 received glargine plus 1 OAD and 525 received glargine plus >1 OAD. Incidence of severe hypoglycaemia was <1%. HbA1c decreased significantly between baseline and end-point for patients receiving glargine plus 1 OAD (−1.4%, p < 0.001; algorithm 1 −1.3% vs. algorithm 2 −1.5%; p = 0.03) and glargine plus >1 OAD (−1.7%, p < 0.001; algorithm 1 −1.5% vs. algorithm 2 −1.8%; p = 0.001). Conclusions: This study shows that initiation of once-daily glargine with OADs results in significant reduction of HbA1c with a low risk of hypoglycaemia. The greater reduction in HbA1c was seen in patients randomized to the patient-driven algorithm (algorithm 2) on 1 or >1 OAD.  相似文献   
75.
76.
77.
BACKGROUND & AIMS: Dietary nucleotides are reported to influence the growth and functioning of the liver and small intestine. The aim of this study was to examine the mechanism by which nucleotides exert their effects in these tissues by assessing protein synthesis activity and related parameters in the presence or absence of dietary nucleotides. METHODS: Rats were fed a purified diet with or without nucleotides for 10 days. Fractional protein synthesis rate, RNA and DNA concentrations, polysome size distribution, and number of ribosomes were assessed. RESULTS: Fractional protein synthesis rates of the liver and small intestine were lower in the nucleotide-deprived group than in the control group. In the liver, RNA concentration was also lower in the nucleotide-deprived group, but values in the small intestine were similar in the two groups. In the liver, deprivation of nucleotides resulted in a reduction in the number of ribosomes and in polysome breakdown. Protein and DNA concentrations did not vary in the liver; however, the concentration of DNA was lower in the small intestine of the nucleotide-deprived group than in the control group. CONCLUSIONS: Dietary nucleotides can modulate protein synthesis in the liver and small intestine as a result of tissue-specific nucleic acid changes. (Gastroenterology 1996 Jun;110(6):1760-9)  相似文献   
78.
79.
80.
Nosocomial pneumonia remains a common problem and is the leading cause of death among patients with nosocomial infection. However, the initial empiric therapy of nosocomial pneumonia is directed at the leading organisms common to all patients, and for many patients monotherapy is adequate for at least 48 hours, at which time the microbiological results of appropriate diagnostic procedures should be known and the treatment can be focused. The currently available antimicrobial agents such as third- and fourth-generation cephalosporins, piperacillin plus tazobactam, carbapenems, and some fluoroquinolones are highly active and bactericidal. They should be used in consideration of current pharmacodynamic knowledge, which will lead to convincing clinical results. Combination of antibiotics is necessary only in specific situations or for the amelioration of special pathogens, such as Pseudomonas aeruginosa, Acinetobacter spp., and against mixed aerobic and anaerobic infections.  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