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   6132篇
  免费   413篇
  国内免费   81篇
耳鼻咽喉   69篇
儿科学   153篇
妇产科学   52篇
基础医学   794篇
口腔科学   126篇
临床医学   685篇
内科学   1422篇
皮肤病学   149篇
神经病学   443篇
特种医学   450篇
外科学   860篇
综合类   46篇
一般理论   5篇
预防医学   385篇
眼科学   214篇
药学   392篇
中国医学   7篇
肿瘤学   374篇
  2023年   43篇
  2022年   87篇
  2021年   147篇
  2020年   86篇
  2019年   147篇
  2018年   185篇
  2017年   135篇
  2016年   169篇
  2015年   206篇
  2014年   244篇
  2013年   342篇
  2012年   432篇
  2011年   464篇
  2010年   287篇
  2009年   254篇
  2008年   355篇
  2007年   389篇
  2006年   368篇
  2005年   323篇
  2004年   273篇
  2003年   294篇
  2002年   245篇
  2001年   86篇
  2000年   77篇
  1999年   71篇
  1998年   81篇
  1997年   75篇
  1996年   49篇
  1995年   45篇
  1994年   51篇
  1993年   35篇
  1992年   41篇
  1991年   52篇
  1990年   33篇
  1989年   42篇
  1988年   50篇
  1987年   34篇
  1986年   19篇
  1985年   28篇
  1984年   27篇
  1983年   23篇
  1982年   18篇
  1981年   22篇
  1980年   16篇
  1978年   16篇
  1977年   16篇
  1976年   17篇
  1975年   12篇
  1974年   16篇
  1972年   13篇
排序方式: 共有6626条查询结果,搜索用时 37 毫秒
71.
72.
The tyrosine kinase inhibitors sorafenib and sunitinib are approved for the treatment of patients with malignant diseases. To analyze the possible use of these compounds in combination with immunotherapeutic approaches, we analyzed the effects of both inhibitors on the immunostimulatory capacity of human dendritic cells (DCs) and the induction of primary immune responses in vivo. Sorafenib, but not sunitinib, inhibits function of DCs, characterized by reduced secretion of cytokines and expression of CD1a, major histocompatibility complex, and costimulatory molecules in response to TLR ligands as well as by their impaired ability to migrate and stimulate T-cell responses. These inhibitory effects are mediated by inhibition of PI3 and MAP kinases and NFB signaling. In contrast, sorafenib had no influence on the phenotype and proliferation of T cells. To analyze the effects of both TKIs on cytotoxic T-cell induction in vivo, C57BL/6 mice were pretreated with sorafenib or sunitinib and immunized with OVA257-264 peptide. Sorafenib, but not sunitinib, application significantly reduced the induction of antigen-specific T cells. Numbers of regulatory T cells were reduced in peripheral blood mononuclear cells from mice treated with sunitinib. These results indicate that sunitinib, but not sorafenib, is suitable for combination with immunotherapeutic approaches for treatment of cancer patients.  相似文献   
73.
74.
The present study aimed to elucidate the profile of coping in patients with obsessive–compulsive disorder (OCD) in order to discern whether the disorder is characterized by an excess of maladaptive coping skills and/or a lack of adaptive coping skills. Sixty individuals with OCD were compared with 110 individuals with depression and 1050 nonclinical controls on the Maladaptive and Adaptive Coping Styles Questionnaire (MAX). Psychopathology was assessed with the Obsessive–Compulsive Inventory-Revised (OCI-R), the Yale-Brown Obsessive–Compulsive Scale (Y-BOCS), and the Patient Health Questionnaire-9 for depression (PHQ-9). Individuals with OCD and depression displayed more maladaptive coping and avoidance as well as less adaptive coping than nonclinical controls. Importantly, adaptive coping was significantly lower in individuals with OCD than in those with depression at a medium effect size, whereas the clinical groups were indistinguishable on maladaptive coping and avoidance. Lack of adaptive coping was strongly correlated with resistance to symptoms and poor insight in OCD (Y-BOCS), even after controlling for depression. Lack of adaptive coping skills may represent a specific pathogenetic factor in OCD. Longitudinal studies need to clarify whether strengthening adaptive skills during childhood and adolescence may help to prevent the progression from subclinical to manifest OCD.  相似文献   
75.
76.
77.
78.
Large clonal expansions of peripheral CD8+ T cells carrying receptors for single epitopes of CMV and EBV are common in the elderly and may be associated with an immune risk phenotype predicting mortality. Here we show that the frequency of CD8+ T cells expressing the inhibitory killer cell lectin-like receptor G1 (KLRG1), a marker of cells unable to undergo further clonal expansion, was markedly elevated in CD8+ T cells from old donors. Moreover, tetramer staining revealed that the elevated frequency of CMV-specific CD8+ T cells in the elderly was due to an accumulation of cells bearing this dominant negative receptor. The fraction of CMV-specific T cells able to secrete interferon-gamma after specific antigenic stimulation was significantly lower in the elderly than in the young, although the total number of functional cells was comparable. Therefore, the majority of the clonally expanded virus-specific CD8+ cells in the elderly was dysfunctional. Thus, T cell responses are altered in the aged by an accumulation of replicatively senescent dysfunctional T cells carrying receptors for persistent herpes viruses. The presence of clonal expansions of such virus-specific cells may shrink the available repertoire for other antigens and contribute to the increased incidence of infectious disease in the elderly.  相似文献   
79.
Stent treatment of coronary artery bifurcation lesions.   总被引:1,自引:0,他引:1  
  相似文献   
80.
ContextEpisodic breathlessness is characterized by a severe worsening of breathlessness intensity that goes beyond usual fluctuations. Episodes are usually short; therefore, nonpharmacological strategies (cognitive and behavioral) seem most promising to be beneficial. Which strategies—delivered separately or in combination—might be most effective and feasible remains unclear.ObjectivesThe Delphi survey selects and determines different nonpharmacological strategies for coping with episodic breathlessness to develop a brief cognitive and behavioral intervention for the management of episodic breathlessness.MethodsUsing an online Delphi survey comprising three rounds, international, multidisciplinary experts in breathlessness summarized and determined cognitive and behavioral strategies. The a priori target agreement for close-ended questions was 70%.ResultsExperts (n = 41/87; n = 45/85; n = 36/85) agreed on 15 of the 31 cognitive and behavioral strategies. Based on the panellists' opinion, the final version of the cognitive and behavioral intervention comprised the following characteristics: individually tailored intervention, a high proportion of communication, short duration, the involvement of carers, and use of the Breathing, Thinking, Functioning Model of Spathis et al. Consensus upon the delivery of the subsequent strategies within the intervention was reached: handheld fan, forward lean, diaphragmatic breathing, distraction, pursed lips breathing, long breaths out, and relaxation training.ConclusionUsing the consented nonpharmacological strategies, a brief cognitive and behavioral intervention was developed that balances between individualization and standardization of the intervention.  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