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   176629篇
  免费   1027篇
  国内免费   14篇
耳鼻咽喉   1143篇
儿科学   6710篇
妇产科学   3100篇
基础医学   16686篇
口腔科学   1716篇
临床医学   12424篇
内科学   30971篇
皮肤病学   702篇
神经病学   16474篇
特种医学   8940篇
外国民族医学   2篇
外科学   29017篇
综合类   2353篇
一般理论   1篇
预防医学   18161篇
眼科学   2743篇
药学   9506篇
中国医学   632篇
肿瘤学   16389篇
  2022年   27篇
  2021年   46篇
  2020年   31篇
  2019年   58篇
  2018年   21958篇
  2017年   17390篇
  2016年   19530篇
  2015年   925篇
  2014年   827篇
  2013年   800篇
  2012年   7000篇
  2011年   21057篇
  2010年   18850篇
  2009年   11541篇
  2008年   19541篇
  2007年   21706篇
  2006年   564篇
  2005年   2181篇
  2004年   3404篇
  2003年   4353篇
  2002年   2510篇
  2001年   321篇
  2000年   479篇
  1999年   207篇
  1998年   224篇
  1997年   216篇
  1996年   106篇
  1995年   108篇
  1994年   119篇
  1993年   82篇
  1992年   70篇
  1991年   118篇
  1990年   144篇
  1989年   113篇
  1988年   71篇
  1987年   63篇
  1986年   47篇
  1985年   51篇
  1984年   35篇
  1983年   41篇
  1982年   36篇
  1980年   48篇
  1978年   26篇
  1974年   41篇
  1970年   32篇
  1969年   31篇
  1938年   60篇
  1934年   32篇
  1932年   56篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 359 毫秒
951.
952.
A heart under chronic stress undergoes cardiac remodelling, a process that comprises structural and functional changes including cardiomyocyte hypertrophy, interstitial fibrosis, contractile dysfunction, cell death and ventricular dilatation. Reactive oxygen species (ROS)-dependent modulation of intracellular signalling is implicated in the development of cardiac remodelling. Among the different ROS sources that are present in the heart, NADPH oxidases (NOXs) are particularly important in redox signalling. NOX isoforms are expressed in multiple cell types including cardiomyocytes, fibroblasts, endothelial cells and inflammatory cells—with the two main isoforms expressed in the heart being NOX2 and NOX4. Recent studies indicate that NOX-dependent signalling is involved in the development of cardiomyocyte hypertrophy, interstitial fibrosis and post-MI remodelling. NOXs may also be involved in the genesis of contractile dysfunction and myocyte apoptosis. Here, we review the main effects of NOXs in the pathogenesis of cardiac remodelling and the redox-sensitive signalling pathways that underlie these effects. The elucidation of mechanisms involved in NOX-dependent regulation of cardiac remodelling may lead to new therapeutic targets for heart failure.  相似文献   
953.

Aims  

The present study was under taken to evaluate the efficacy of various local and regional soft tissue flaps used for reconstruction after excision of various malignant lesions of the mouth and also to evaluate complications with length of hospital stay after the reconstruction.  相似文献   
954.
955.
956.
Sinusitis is a frequent complication of respiratory tract infections. Probiotics are perceived to be useful in infections, allergies, and inflammations. Our prospective trial stratified 204 children with recurrent rhinosinusitis by age (2–11 years, 54m:64f; 12–18 years, 39m:47f) and assigned them to standard treatment (antibiotics, anticongestants) or additional 60 days Symbioflor-1 (SF1; Enterococcus faecalis 1.5–4.5x107 CFU). The number of sinusitis episodes was lower in SF1-treated patients (2.52±0.91) than among controls (3.27±1.36; p=0.01). Mean duration of the first sinusitis episode was 11.9±8.6 days with SF1, whereas it was 16.1±12.9 days in the younger controls (p=0.023) and 9.86±5.05 days in the elder controls (n.s.). Duration of subsequent sinusitis episodes was also shorter in SF1 patients (15.2±13.6 days) compared with controls (22.7±14.8 days; p=0.030). No adverse events were observed. Probiotic Enterococcus faecalis adjuvant to conventional therapy can reduce the number and duration of rhinosinusitis episodes in children and adolescents.  相似文献   
957.
Renal osteodystrophy (ROD) is a metabolic skeletal pathology that frequently affects the orofacial region and presents with characteristic radiological manifestations. This paper reports a case of ROD causing diffused orofacial bone alterations in a female patient with end-stage chronic kidney disease. The radiological features on panoramic, posteroanterior and lateral skull and computed tomography radiographs are described for this case. Previous reports in the literature are reviewed and discussed with a focus on radiological characteristics and differential diagnoses.  相似文献   
958.
Randomized clinical trials (RCTs) are relied upon for determining the standard of care and changes to the standard of care in oncology. Through data sharing, the pooled individual patient data (IPD) from these trials can provide high-quality sources and enriched power for analyses beyond the original goals of each trial. To address important scientific questions in early-stage colon cancer, the Adjuvant Colon Cancer End Points (ACCENT) Collaborative Group has continuously integrated IPD from large adjuvant colon cancer RCTs conducted worldwide. Through June 2016, IPD from over 40,000 patients from 27 major trials (1977 to 2009) have been assembled. Over the past 20 years, a variety of clinical questions have been investigated and addressed by ACCENT collaborations. Many of the findings have provided additional understanding of treatment mechanisms, suggested changes or reinforced quality patient care, and informed and improved the design for the current and next generation of RCTs. We review these significant contributions from the ACCENT collaboration.  相似文献   
959.
Autism spectrum disorder (ASD) is a neurodevelopmental disorder afflicting about one in every 68 children. It is behaviorally diagnosed based on a triad of symptoms, including impairment in communication, impairment in sociability and abnormal and stereotypic behavior. The subjectivity of behavioral diagnosis urges the need for clinical biomarker tests to improve and complement ASD diagnosis and treatment. Over the past two decades, researchers garnered a broad range of biomarkers associated with ASD and often correlating with the severity of ASD, which includes metabolic and genetic biomarkers or neuroimaging abnormalities. Metabolic biomarkers are either involved in key pathways such as a trans-sulfuration pathway or produced due to the derangement of these pathways in the case of oxidative stress. Recent studies reported several genetic abnormalities related to ASD, encompassing various mechanisms, from copy number variations (CNVs) and single nucleotide polymorphisms (SNPs) to chromosomal anomalies. However, it is still premature to consider these genetic variants as true biomarkers for ASD, due to their low reproducibility and regional-specific nature. Herein, we comprehensively review state of the art about major biomarkers reported in ASD and the association of some biomarkers with ASD symptoms and severity. It is important to establish those biomarkers to be able to help in the diagnosis and to optimize the treatment of ASD.  相似文献   
960.
Agency leaders and therapists are essential stakeholders in implementation of evidence-based practices (EBPs) within publicly-funded mental health services. Little is known about how these stakeholders differ in their perceptions of specific EBPs and which individual and organizational factors differentially influence these perceptions. Within the context of a system-driven implementation of multiple EBPs, survey data from 160 leaders and 720 therapists were examined to assess differences in perceptions of six EBPs. Findings indicated that leaders and therapists have unique perspectives and preferences regarding EBPs that are shaped by distinct sociodemographic and professional characteristics and aspects of organizational functioning.  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