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   1436篇
  免费   112篇
  国内免费   14篇
耳鼻咽喉   5篇
儿科学   32篇
妇产科学   32篇
基础医学   254篇
口腔科学   83篇
临床医学   134篇
内科学   342篇
皮肤病学   23篇
神经病学   175篇
特种医学   49篇
外科学   103篇
综合类   2篇
一般理论   1篇
预防医学   92篇
眼科学   51篇
药学   77篇
中国医学   4篇
肿瘤学   103篇
  2023年   12篇
  2022年   21篇
  2021年   64篇
  2020年   38篇
  2019年   55篇
  2018年   62篇
  2017年   59篇
  2016年   53篇
  2015年   59篇
  2014年   81篇
  2013年   94篇
  2012年   133篇
  2011年   145篇
  2010年   75篇
  2009年   60篇
  2008年   78篇
  2007年   72篇
  2006年   81篇
  2005年   89篇
  2004年   55篇
  2003年   53篇
  2002年   38篇
  2001年   8篇
  2000年   6篇
  1999年   2篇
  1998年   6篇
  1997年   7篇
  1996年   3篇
  1995年   4篇
  1994年   3篇
  1993年   6篇
  1992年   5篇
  1990年   1篇
  1989年   3篇
  1988年   1篇
  1987年   1篇
  1985年   2篇
  1984年   2篇
  1983年   3篇
  1982年   1篇
  1981年   5篇
  1980年   2篇
  1979年   3篇
  1977年   2篇
  1976年   1篇
  1975年   1篇
  1974年   3篇
  1969年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有1562条查询结果,搜索用时 156 毫秒
31.
Journal of Interventional Cardiac Electrophysiology - Delineate retrospectively and prospectively the incidence and characteristics of transient ST-segment elevation during transseptal puncture....  相似文献   
32.
33.
Patients infected with HIV-1, the etiological agent of AIDS, have increased intestinal permeability, which allows for the passage of microbial products, including Toll-like receptor (TLR) ligands, into circulation. The exposure of HIV-1-infected cells to certain TLR agonists affects viral replication, but studies associating viral production with the activation of TLR2 in HIV-1-infected cells are rare and controversial. Here, we report that the TLR2 ligands Zymosan and Pam3CSK4 potently inhibit HIV-1 replication in acutely infected monocyte-derived macrophages and the exposure to TLR2 ligands prior to infection renders macrophages refractory to HIV-1 production. Macrophage treatment with Pam3CSK4 did not change the cellular expression of the HIV-1 entry receptors CD4 and CCR5. Both TLR2 ligands increased the macrophage production of β-chemokines and IL-10, and the blockage of these soluble factors prevented the inhibitory effect of TLR2 activation on HIV-1 replication. Our findings show that the direct engagement of TLR2 in HIV-1-infected macrophages increase cellular resistance to HIV-1 infection, and that controlling HIV-1 replication with agonists for TLR2 might have implications for the development of antiretroviral therapies.  相似文献   
34.
Cognition can be deteriorated in older persons because of several potential mechanisms including the hormonal changes occurring with age. Stress events cause modification in hormonal balance with acute and chronic changes such as increase in cortisol and thyroid hormones, and simultaneous alterations in dehydroepiandrosterone sulphate, testosterone and insulin like growth factor-1 levels. The ability to cope with stress and regain previous healthy status, also called resiliency, is particularly impaired in older persons Thus, stressful conditions and hormonal dysregulation might concur to the onset of cognitive impairment in this population.  相似文献   
35.
Mutations in AarF domain‐containing kinase 3 (ADCK3) are responsible for the most frequent form of hereditary coenzyme Q10 (CoQ10) deficiency (Q10 deficiency‐4), which is mainly associated with autosomal recessive cerebellar ataxia type 2 (ARCA2). Clinical presentation is characterized by a variable degree of cerebellar atrophy and a broad spectrum of associated symptoms, including muscular involvement, movement disorders, neurosensory loss, cognitive impairment, psychiatric symptoms and epilepsy. In this report, we describe, for the first time, a case of photoparoxysmal response in a female patient with a mutation in ADCK3. Disease onset occurred in early childhood with gait ataxia, and mild‐to‐moderate degeneration. Seizures appeared at eight years and six months, occurring only during sleep. Photoparoxysmal response was observed at 14 years, almost concomitant with the genetic diagnosis (c.901C>T;c.589‐3C>G) and the start of CoQ10 oral supplementation. A year later, disease progression slowed down, and photosensitivity was attenuated. A review of the literature is provided focusing on epileptic features of ADCK3‐related disease as well as the physiopathology of photoparoxysmal response and supposed cerebellar involvement in photosensitivity. Moreover, the potential role of CoQ10 oral supplementation is discussed. Prospective studies on larger populations are needed to further understand these data.  相似文献   
36.
Statement of problemHow the properties of the implant-abutment unit may affect the peri-implant soft-tissue seal, whose stability is considered key to safeguarding the implant from bacterial contamination and preserve peri-implant health conditions, is unclear.PurposeThe purpose of this systematic review and meta-analysis of animal studies was to investigate whether material and surface properties of transmucosal implant components can influence the peri-implant soft-tissue adhesion at a histological level.Material and methodsAn electronic and hand search was conducted until August 2019. Histological animal studies comparing soft-tissue response to abutment or transmucosal collar with different materials and/or surface characteristics were selected by 2 independent reviewers. Risk of bias in individual studies was evaluated. Histomorphometric data on the dimension of the peri-implant attachment were recorded, and a quantitative synthesis by a meta-analysis was performed. Risk of bias in individual studies was evaluated in accordance with the Systematic Review Centre for Laboratory Animal Experimentation Risk of Bias tool.ResultsEighteen relevant studies out of 1187 were identified, none with a low risk of bias for all domains. Data from only 4 studies could be meta-analyzed. Comparable results in terms of peri-implant attachment dimensions between test and control groups were found, except for a significantly higher apical junctional epithelium to coronal bone to implant (ajE-CBI) distance for chemically modified acid-etched compared with titanium machined surfaces. Non–meta-analyzable and/or qualitative results highlighted some improved properties also for microgrooved and oxidized surfaces.ConclusionsLimited data from animal studies suggest that some characteristics of the transmucosal implant components may affect peri-implant soft-tissue adhesion and stabilization but do not allow definitive conclusions. Future research should improve study design to increase the availability of comparable and suitable data on this topic.  相似文献   
37.
Impaired balance and gait performance increase fall-risk in seniors. Acute effects of different exercise bouts on gait and balance were not yet addressed. Therefore, 19 healthy seniors (10 women, 9 men, age: 64.6 ± 3.2 years) were examined on 3 days. After exhaustive treadmill testing, participants randomly completed a 2-km treadmill walking test (76 ± 8 % VO2max) and a resting control condition. Standing balance performance (SBALP) was assessed by single limb-eyes opened (SLEO) and double limb-eyes closed (DLEC) stance. Gait parameters were collected at comfortable walking velocity. A condition × time interaction of center of pressure path length (COPpath) was observed for both balance tasks (p < 0.001). Small (Cohen’s d = 0.42, p = 0.05) and large (d = 1.04, p < 0.001) COPpath increases were found after 2-km and maximal exercise during DLEC. Regarding SLEO, slightly increased COPpath occurred after 2-km walking (d = 0.29, p = 0.65) and large increases after exhaustive exercise (d = 1.24, p < 0.001). No significant differences were found for gait parameters. Alterations of SBALP after exhaustive exercise might lead to higher fall-risk in seniors. Balance changes upon 2-km testing might be of minor relevance. Gait is not affected during single task walking at given velocities.  相似文献   
38.
39.
The International Journal of Cardiovascular Imaging - The aim of our study was to assess the anatomical changes of the mitral valve apparatus after percutaneous repair with the MitraClip®...  相似文献   
40.
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