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   176309篇
  免费   1063篇
  国内免费   8篇
耳鼻咽喉   1134篇
儿科学   6764篇
妇产科学   3034篇
基础医学   16642篇
口腔科学   1539篇
临床医学   12508篇
内科学   30930篇
皮肤病学   674篇
神经病学   16553篇
特种医学   8928篇
外科学   28794篇
综合类   2376篇
一般理论   2篇
预防医学   18233篇
眼科学   2735篇
药学   9528篇
中国医学   626篇
肿瘤学   16380篇
  2022年   29篇
  2021年   69篇
  2020年   44篇
  2019年   54篇
  2018年   21970篇
  2017年   17387篇
  2016年   19555篇
  2015年   923篇
  2014年   832篇
  2013年   826篇
  2012年   7033篇
  2011年   21045篇
  2010年   18821篇
  2009年   11533篇
  2008年   19525篇
  2007年   21736篇
  2006年   592篇
  2005年   2215篇
  2004年   3388篇
  2003年   4382篇
  2002年   2528篇
  2001年   286篇
  2000年   423篇
  1999年   163篇
  1998年   215篇
  1997年   216篇
  1996年   98篇
  1995年   108篇
  1994年   107篇
  1993年   70篇
  1992年   47篇
  1991年   85篇
  1990年   128篇
  1989年   80篇
  1988年   62篇
  1987年   39篇
  1986年   30篇
  1985年   35篇
  1984年   27篇
  1983年   27篇
  1982年   33篇
  1980年   49篇
  1974年   26篇
  1939年   22篇
  1938年   61篇
  1937年   25篇
  1935年   23篇
  1934年   30篇
  1932年   57篇
  1930年   46篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The Subjective Visual Vertical (SVV) is a common test for evaluating the perception of verticality. Altered verticality has been connected with disorders in the otolithic, visual or proprioceptive systems, caused by stroke, Parkinson’s disease or multiple sclerosis, among others. Currently, this test is carried out using a variety of specific, mostly homemade apparatuses that include moving planes, buckets, hemispheric domes or a line projected in a screen. Our aim is to develop a flexible, inexpensive, user-friendly and easily extensible system based on virtual reality for the measurement of the SVV and several related visual diagnostic tests, and validate it through an experimental evaluation. Two different hardware configurations were tested with 50 healthy volunteers in a controlled environment; 28 of them were males and 22 females, with ages ranging from 18 to 49 years, being 23 the average age. The Intraclass Correlation Coefficient (ICC) was computed in each device. In addition, a usability survey was conducted. ICC?=?0.85 in the first configuration (CI?=?0.75–0.92), ICC?=?0.76 in the second configuration (CI?=?0.61–0.87), both with 95% of confidence, which means a substantial reliability. Moreover, 92.2% of subjects rated the usability of the system as “very good”. Our evaluation showed that the proposed system is suitable for the measurement of SVV in healthy subjects. The next step is to perform a more elaborated experimentation on patients and compare the results with the measurements obtained from traditional methods.  相似文献   
992.
HIV testing is the gateway to biomedical means of prevention and treatment. Identifying predictors of HIV testing is important to inform future preventive interventions. Of 444 men who have sex with men without known HIV infection enrolled in a study in Hong Kong, 64% had ever been HIV-tested. Testers were generally older, better educated, had a higher monthly income, and more likely self-identified as gay. Testers often used Internet and frequented saunas for sex networking, compared with non-testers attending bars, massage centres and public toilets. HIV testing habit also varied with the profile of body image type and preferred type in sex networking. Higher acceptance of pre-exposure prophylaxis (PrEP) was observed among testers. Overall, socioeconomic status played an important role in both HIV testing and access to PrEP. Interventions targeting sex networking venues and alternative means of testing provision are needed to increase coverage of HIV testing.  相似文献   
993.
994.
The predictive value of vascular biomarkers such as pulse wave velocity (PWV), central arterial pressure (CAP), and augmentation index (AIx), obtained through pulse wave analysis (PWA) in resting conditions, has been documented in a variety of patient groups and populations. This allowed to make appropriate recommendations in clinical practice guidelines of several scientific societies. Due to advances in technologies, largely operator-independent methods are currently available for estimating vascular biomarkers also in ambulatory conditions, over the 24 h. According to the acceptable accuracy and reproducibility of 24-h ambulatory PWA, it appears to be a promising tool for evaluating vascular biomarkers in daily life conditions. This approach may provide an opportunity to further improve the early cardiovascular screening in subjects at risk. However, concerning the clinical use of PWA over the 24 h in ambulatory conditions at the moment, there is no sufficient evidence to support its routine clinical use. In particular, long-term outcome studies are needed to show the predictive value of 24-h PWV, CAP, and AIx values, provided by these devices, over and beyond peripheral blood pressure, and to answer the many technical and clinical questions still open. To this regard, the VASOTENS Registry, an international observational prospective study recently started, will help providing answers on a large sample of hypertensive patients recruited worldwide.  相似文献   
995.
Esophageal intramural pseudodiverticulosis (EIP) is a rare disorder of unknown etiology. On histopathology, it is characterized by dilation of the submucosal esophageal glands. The main presenting symptom is dysphagia to solid foods. Most patients diagnosed with EIP also have a history of diabetes mellitus, gastroesophageal reflux disease, esophageal candidiasis, or chronic alcohol and nicotine abuse. Yet, the exact pathophysiologic mechanism still remains unclear. The most frequent complication, occurring in 80 % of the patients, is esophageal stricture. The mainstay of therapy is directed towards symptom relief with administration of proton pump inhibitors (PPIs) combined with antifungals and/or endoscopic dilations, if necessary. We report a case of a 69-year-old man who presented with a 9-month history of progressive dysphagia and a 25 kg-weight loss, with typical endoscopic findings of EIP and successful response to medical therapy with oral antifungals alone.  相似文献   
996.
997.
998.
The purpose of this study is to summarize the manifestations, diagnosis, differential diagnosis, and treatment of childhood brucellosis in non-epidemic areas of China. A retrospective review of 16 admitted children patients with brucella’s disease who were diagnosed of brucellosis during the period from 2011 to 2016 was performed. Diagnostic criteria, clinical presentations, and outcomes were recorded. The most common symptom was fever. Osteoarticular involvement was found in 50% of the patients. They were infected by contacting with infected animals or consuming of unpasteurized milk or meat of sheep or goats, also. Standard agglutination test was positive in all patients and blood culture in 10 (62.5%) patients as well as medulloculture in 3 (18.8%) patients were positive. A combination of antibiotic treatment with rifampin plus cotrimoxazole showed good response and all clinical manifestations improved. Brucellosis is misdiagnosed frequently and should be considered in the differential diagnosis when patients do not respond to standard treatment. Blood culture, together with brucella serology test, is important and helpful in the diagnosis. MRI is a good method in differentiating those with symptoms of arthritis.  相似文献   
999.
Yi Chai 《Tumour biology》2016,37(3):2817-2821
Biliary tract cancers (BTCs), which encompass intra- and extrahepatic cholangiocarcinomas as well as gallbladder carcinomas, are one of the most aggressive malignancies. Although the development of systemic chemotherapy approaches has made progress, the prognosis of BTC remains poor. Chronic inflammation plays an important role in the carcinogenesis of BTC, highlighting the immune etiology of this disease. Immunotherapy has emerged as a promising new modality of treatment for BTC. Here, we summarize the relevant tumor immunology of BTC and recently completed and ongoing clinical trials of immunotherapy for BTC.  相似文献   
1000.
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