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   3745篇
  免费   220篇
  国内免费   10篇
耳鼻咽喉   41篇
儿科学   65篇
妇产科学   80篇
基础医学   481篇
口腔科学   26篇
临床医学   311篇
内科学   1122篇
皮肤病学   73篇
神经病学   385篇
特种医学   132篇
外科学   317篇
综合类   8篇
一般理论   1篇
预防医学   312篇
眼科学   40篇
药学   196篇
中国医学   3篇
肿瘤学   382篇
  2023年   14篇
  2022年   28篇
  2021年   126篇
  2020年   67篇
  2019年   120篇
  2018年   101篇
  2017年   87篇
  2016年   76篇
  2015年   88篇
  2014年   134篇
  2013年   172篇
  2012年   276篇
  2011年   296篇
  2010年   173篇
  2009年   151篇
  2008年   254篇
  2007年   238篇
  2006年   228篇
  2005年   197篇
  2004年   202篇
  2003年   156篇
  2002年   191篇
  2001年   65篇
  2000年   51篇
  1999年   74篇
  1998年   40篇
  1997年   35篇
  1996年   45篇
  1995年   40篇
  1994年   12篇
  1993年   12篇
  1992年   38篇
  1991年   23篇
  1990年   28篇
  1989年   28篇
  1988年   28篇
  1987年   14篇
  1986年   7篇
  1985年   10篇
  1984年   11篇
  1983年   8篇
  1982年   8篇
  1981年   6篇
  1980年   4篇
  1979年   2篇
  1977年   2篇
  1975年   3篇
  1968年   1篇
  1967年   1篇
  1966年   1篇
排序方式: 共有3975条查询结果,搜索用时 15 毫秒
1.
2.
Over 36 million people worldwide are infected with HIV. Antiretroviral therapy (ART) has proven to be highly effective to prevent HIV-1 transmission, clinical progression and death. Despite this success, the number of HIV-1 infected individuals continues increasing and ART should be taken for life. Therefore, there are two main priorities: the development of preventive vaccines to protect from HIV acquisition and achieve an efficient control of HIV infection in the absence of ART (functional cure). In this sense, in the last few years, there has been a broad interest in new and innovative approaches such as mRNA-based vaccines. RNA-based immunogens represent a promising alternative to conventional vaccines because of their high potency, capacity for rapid development and potential for low-cost manufacture and safe administration. Some mRNA-based vaccines platforms against infectious diseases have demonstrated encouraging results in animal models and humans. However, their application is still limited because the instability and inefficient in vivo delivery of mRNA. Immunogens, design, immunogenicity, chemical modifications on the molecule or the vaccine delivery methods are all crucial interventions for improvement. In this review we, will present the current knowledge and challenges in this research field. mRNA vaccines hold great promises as part of a combined strategy, for achieving HIV functional cure.  相似文献   
3.
4.
5.
6.
We assessed predictors of spontaneous early neurological recovery after acute ischemic stroke by means of multivariate analysis in a cohort of 1,473 consecutive patients treated at one academic center. At hospital discharge, spontaneous neurological improvement or good outcome was defined as grades 0-2 of the Rankin scale, and poor outcome (no improvement or in-hospital death) as grades 3-5. Spontaneous recovery of neurological deficit at the time of discharge from the hospital was observed in 16% of patients with cerebral infarction (n = 238). Dysarthria-clumsy hand syndrome improved in 44% of patients and was the only variable significantly associated with in-hospital functional recovery in three logistic regression models that in addition to lacunar syndromes, included demographic variables, cardiovascular risk factors, and clinical variables [odds ratio (OR) 2.56], neuroimaging findings (OR 2.48), and outcome data (OR 2.39), respectively. Clinical factors related to severity of infarction available at stroke onset have a predominant influence upon in-hospital outcome and may help clinicians to assess prognosis more accurately. Our work gives a contribution into prognostic factors after acute ischemic stroke. With regard to patterns of stroke, dysarthria-clumsy hand syndrome was a significant predictor of spontaneous in-hospital recovery in ischemic stroke patients.  相似文献   
7.
We evaluated the occurrence of REM sleep behaviour disorder (RBD) and vocal cord abductor paralysis (VCAP) in a group of 9 Machado-Joseph disease (MJD) patients. RBD was diagnosed by clinical history plus audiovisual polysomnography in 4 men and 1 woman (55%). While dreaming, 4 fell out of the bed and the other injured his arms. Laryngoscopy detected bilateral VCAP in 1 patient with stridor who required emergency tracheotomy, and partial vocal cord abductor restriction in 2. RBD and VCAP are two potentially injurious conditions that should be considered part of the clinical spectrum of MJD.  相似文献   
8.
9.
10.
A comparison was performed between technetium-99m tetrofosmin myocardial perfusion tomography at baseline and after nitrate administration, using a 2-day protocol, and rest-reinjection thallium-201 single-photon emission tomography (SPET) studies in order to assess whether nitrates enhance the detection of viable myocardium with99mTc-tetrofosmin. Fifteen patients with coronary artery disease, previous myocardial infarction and a left ventricular ejection fraction <40% underwent201T1 rest-injection and99mTc-tetrofosmin. baseline-postnitroglycerin (0.4 mg sublingually) SPET studies, within 48 h. Tomograms based on the three spatial planes were divided into 15 segments and regional tracer uptake was quantitatively analysed. Viability was defined as presence of tracer uptake >50% of peak activity on baseline studies or after reversibility. The percentage of peak activity of99mTc-tetrofosmin at baseline correlated with that of 201T1 (r=0.82,P <0.001). On baseline99mTc-tetrofosmin studies, 73 of the 225 segments that were analysed had <50% of peal. activity. Fifteen percent of these segments showed reversibility after nitrate administration, with an increase in99mTc-tetrofosmin uptake from 40%±9% to 57%±9% of peak activity (P=0.003). All reversible segments after nitrate administration had viability criteria on201Tl studies, but 20 segments that were non-viable on99mTc-tetrofosmin. studies were viable on201Tl studies. Using a threshold value of >40% of peak activity, only seven segments remained non-viable on99mTc-tetrofosmin studies. Overall agreement between99mTc-tetrofosmin with nitrates and201Tl-reinjection regarding the presence of myocardial viability was 90%. Detection of myocardial viability with99mTc-tetrofosmin. was enhanced after nitrate administration, correlating with viability criteria observed on thallium studies.  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