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   30222篇
  免费   3534篇
  国内免费   734篇
耳鼻咽喉   307篇
儿科学   827篇
妇产科学   454篇
基础医学   2280篇
口腔科学   273篇
临床医学   4239篇
内科学   5472篇
皮肤病学   262篇
神经病学   6259篇
特种医学   554篇
外国民族医学   2篇
外科学   4545篇
综合类   3257篇
预防医学   1810篇
眼科学   356篇
药学   2048篇
  17篇
中国医学   985篇
肿瘤学   543篇
  2024年   41篇
  2023年   751篇
  2022年   907篇
  2021年   1807篇
  2020年   1786篇
  2019年   1768篇
  2018年   1635篇
  2017年   1673篇
  2016年   1566篇
  2015年   1441篇
  2014年   2342篇
  2013年   2670篇
  2012年   1689篇
  2011年   1727篇
  2010年   1389篇
  2009年   1402篇
  2008年   1378篇
  2007年   1223篇
  2006年   1248篇
  2005年   979篇
  2004年   784篇
  2003年   745篇
  2002年   561篇
  2001年   470篇
  2000年   348篇
  1999年   273篇
  1998年   176篇
  1997年   189篇
  1996年   173篇
  1995年   138篇
  1994年   156篇
  1993年   106篇
  1992年   120篇
  1991年   99篇
  1990年   90篇
  1989年   83篇
  1988年   73篇
  1987年   68篇
  1986年   73篇
  1985年   42篇
  1984年   56篇
  1983年   43篇
  1982年   45篇
  1981年   33篇
  1980年   41篇
  1979年   24篇
  1978年   21篇
  1977年   11篇
  1976年   9篇
  1975年   7篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
ObjectiveThe use of mechanical circulatory support (MCS) in lung transplantation has been steadily increasing over the prior decade, with evolving strategies for incorporating support in the preoperative, intraoperative, and postoperative settings. There is significant practice variability in the use of these techniques, however, and relatively limited data to help establish institutional protocols. The objective of the AATS Clinical Practice Standards Committee (CPSC) expert panel was to review the existing literature and establish recommendations about the use of MCS before, during, and after lung transplantation.MethodsThe AATS CPSC assembled an expert panel of 16 lung transplantation physicians who developed a consensus document of recommendations. The panel was broken into subgroups focused on preoperative, intraoperative, and postoperative support, and each subgroup performed a focused literature review. These subgroups formulated recommendation statements for each subtopic, which were evaluated by the entire group. The statements were then developed via discussion among the panel and refined until consensus was achieved on each statement.ResultsThe expert panel achieved consensus on 36 recommendations for how and when to use MCS in lung transplantation. These recommendations included the use of veno-venous extracorporeal membrane oxygenation (ECMO) as a bridging strategy in the preoperative setting, a preference for central veno-arterial ECMO over traditional cardiopulmonary bypass during the transplantation procedure, and the benefit of supporting selected patients with MCS postoperatively.ConclusionsAchieving optimal results in lung transplantation requires the use of a wide range of strategies. MCS provides an important mechanism for helping these critically ill patients through the peritransplantation period. Despite the complex nature of the decision making process in the treatment of these patients, the expert panel was able to achieve consensus on 36 recommendations. These recommendations should provide guidance for professionals involved in the care of end-stage lung disease patients considered for transplantation.  相似文献   
2.
3.
认知障碍是指记忆、语言、理解和判断等一个或多个方面的功能障碍,包括轻度认知障碍和各种类型的痴呆症。痴呆症是认知障碍最严重的表现,是一种导致患者日常生活、社会交往和工作能力发生显著变化的综合征。阿尔茨海默病(AD)是最常见的痴呆症类型,其次是血管性痴呆(VD)和其他神经退行性痴呆[1]。已知年龄与认知功能的退化密切相关。  相似文献   
4.
Toxicity resulting from off-target effects, beyond acetylcholine esterase inhibition, for the commonly used organophosphate (OP) insecticides chlorpyrifos (CPS) and malathion (MA) was investigated using Saccharomyces cerevisiae and Caenorhabditis elegans model systems. Mitochondrial damage and dysfunction were observed in yeast following exposure to CPS and MA, suggesting this organelle is a major target. In the C. elegans model, the mitochondrial unfolded protein response pathway showed the most robust induction from CPS and MA treatment among stress responses examined. GABAergic neurodegeneration was observed with CPS and MA exposure. Impaired movement observed in C. elegans exposed to CPS and MA may be the result of motor neuron damage. Our analysis suggests that stress from CPS and MA results in mitochondrial dysfunction, with GABAergic neurons sensitized to these effects. These findings may aid in the understanding of toxicity from CPS and MA from high concentration exposure leading to insecticide poisoning.  相似文献   
5.
ObjectiveDeterioration of the native aortic valve function by a late progression of rheumatic disease is not infrequent in patients who underwent rheumatic mitral valve surgery; however, this phenomenon has not been clearly quantified.MethodsA total of 1155 consecutive patients (age 52.0 ± 12.9 years; 807 female) who underwent rheumatic mitral valve surgery without concomitant aortic valve surgery from 1997 to 2015 were enrolled. The primary end point was the composite of progression to severe aortic valve dysfunction or a requirement of subsequent aortic valve replacements during follow-up. To determine the risk factors of the primary outcome, we performed the generalized linear mixed model.ResultsThe baseline severities of aortic valve were none to trivial in 880 patients (76.2%), mild in 256 patients (22.2%), and moderate in 19 patients (1.6%). The latest 1062 echocardiographic assessments (91.9%; median, 81.2 postoperative months; interquartile range, 37.3-132.1 months) demonstrated 26 cases (0.33%/patient-year) meeting the primary end point during follow-up. Cumulative incidence of the primary end point at 10 years was 0.4% ± 0.3% and 7.4% ± 2.5% depending on the presence of mild or greater aortic valve dysfunction at baseline (P < .01). In multivariable analyses, aortic valve peak pressure gradient (odds ratio, 1.14; 95% confidence interval, 1.10-1.20), aortic regurgitation degree (mild over none: odds ratio, 3.26; 95% confidence interval, 1.15-9.23), and time (odds ratio, 1.30; 95% confidence interval 1.19-1.41) were significantly associated with the occurrence of the primary end point.ConclusionsProgression of severe aortic valve dysfunction and the need for aortic valve replacement are uncommon in patients undergoing rheumatic mitral valve surgery. However, such events were relatively common among those with mild or greater aortic valve dysfunction at the time of mitral valve surgery.  相似文献   
6.
郭双辉  张玉梅 《中国全科医学》2022,25(12):1524-1528
认知功能障碍在肌萎缩侧索硬化(ALS)患者中是普遍存在的,ALS伴认知功能障碍常提示预后不良。近年来对ALS患者认知功能障碍的研究取得了一定的进展,本文对ALS伴认知功能障碍的临床特点、生物标志物、遗传学特征和最新治疗进展进行综述,以期为ALS伴认知功能障碍的临床诊疗提供新思路。  相似文献   
7.
8.
The endothelium is a single-layered structure that responds to physical and chemical signals with various factors it synthesizes. In the early days of its discovery, as the inner wall of the vessels, the endothelium was thought to be a simple barrier that lays on the surface. Over time it is discovered that endothelium maintains body homeostasis with the molecules it synthesizes, despite its simple single-layer structure. It has been accepted as an important organ that contributes to the maintenance of vascular tone, cell adhesion, inflammation, vascular permeability and coagulation. Any imbalance in these physiological and pathological events causes endothelial dysfunction. This can cause many diseases such as atherosclerosis, hypertension, diabetes, or it can occur because of these. Endothelial related disorders may also complicate hematopoietic stem cell transplantation (HSCT), which is used to treat various hematologic and neoplastic diseases. These life-threatening complications include graft-versus-host disease, hepatic veno-occlussive disease, transplant-associated thrombotic microangiopathy and diffuse alveolar hemorrhage. They share a similar pathophysiology involving endothelial cells with different clinical presentations. Therefore, current researche on the issue is putting the endothelium under the spotlight for novel markers and treatment options that should be used to monitor or treat at least some of these complications following HSCT.  相似文献   
9.
Temporomandibular disorders (TMD) impact a significant proportion of the population. Given the range of management strategies, contemporary care should be evidence-informed for different TMD types. A knowledge-to-action rapid review of systematic reviews published in the past 5 years and guidelines published in the past 10 years concerning the management of TMD was conducted. The Cochrane, Embase, MEDLINE, PEDro, and PubMed databases were searched. A qualitative data analysis was undertaken, with quality assessment completed using the AMSTAR 2 checklist. In total, 62 systematic reviews and nine guidelines considering a range of treatment modalities were included. In concordance with current guidelines, moderate evidence supports a multi-modal conservative approach towards initial management. Contrary to existing guidelines, occlusal splint therapy is not recommended due to a lack of supporting evidence. The evidence surrounding oral and topical pharmacotherapeutics for chronic TMD is low, whilst the evidence supporting injected pharmacotherapeutics is low to moderate. In concordance with current guidelines, moderate quality evidence supports the use of arthrocentesis or arthroscopy for arthrogenous TMD insufficiently managed by conservative measures, and open joint surgery for severe arthrogenous disease. Based on this, a management pathway showing escalation of treatment from conservative to invasive is proposed.  相似文献   
10.
Glaucoma is a leading cause of irreversible blindness. The use of topical eye drops to reduce intraocular pressure remains the mainstay treatment. These eye drops frequently contain preservatives designed to ensure sterility of the compound. A growing number of clinical and experimental studies report the detrimental effects of not only these preservatives but also the active pharmaceutical compounds on the ocular surface, with resultant tear film instability and dry eye disease. Herein, we critically appraise the published literature exploring the effects of preservatives and pharmaceutical compounds on the ocular surface.  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