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   1461176篇
  免费   120746篇
  国内免费   6633篇
耳鼻咽喉   18364篇
儿科学   46254篇
妇产科学   38577篇
基础医学   199515篇
口腔科学   38905篇
临床医学   133938篇
内科学   303381篇
皮肤病学   33896篇
神经病学   122090篇
特种医学   59559篇
外国民族医学   277篇
外科学   227337篇
综合类   33561篇
现状与发展   3篇
一般理论   594篇
预防医学   118154篇
眼科学   30963篇
药学   102572篇
  7篇
中国医学   2401篇
肿瘤学   78207篇
  2018年   15608篇
  2017年   12324篇
  2016年   14644篇
  2015年   16591篇
  2014年   23193篇
  2013年   34862篇
  2012年   43640篇
  2011年   46709篇
  2010年   28839篇
  2009年   28134篇
  2008年   43897篇
  2007年   46863篇
  2006年   47878篇
  2005年   46667篇
  2004年   44422篇
  2003年   43434篇
  2002年   40984篇
  2001年   67630篇
  2000年   69228篇
  1999年   58142篇
  1998年   18340篇
  1997年   16339篇
  1996年   17115篇
  1995年   17266篇
  1994年   15959篇
  1993年   15031篇
  1992年   48010篇
  1991年   46654篇
  1990年   44810篇
  1989年   42593篇
  1988年   39505篇
  1987年   38768篇
  1986年   36578篇
  1985年   35418篇
  1984年   27257篇
  1983年   22999篇
  1982年   14926篇
  1981年   13470篇
  1980年   12608篇
  1979年   24151篇
  1978年   17730篇
  1977年   14941篇
  1976年   13680篇
  1975年   14194篇
  1974年   16546篇
  1973年   15787篇
  1972年   14492篇
  1971年   13295篇
  1970年   12125篇
  1969年   11286篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them.  相似文献   
72.
73.
This study explored the relationship between active mediation, exposure to Daniel Tiger’s Neighborhood, and key indicators of preschoolers’ social and emotional development. One hundred and twenty-seven children aged 2–6 either watched or did not watch 10 episodes of Daniel Tiger’s Neighborhood over a two-week period. Results revealed that preschoolers who watched the program exhibited higher levels of empathy, self-efficacy, and emotion recognition when their regular TV-watching experiences are frequently accompanied by active mediation. This was especially true for younger preschoolers and preschoolers from low-income families. Implications for policy-makers, parents, producers of prosocial programming, and educators are discussed.  相似文献   
74.
75.
76.
77.
Graefe's Archive for Clinical and Experimental Ophthalmology - Retinal microvascular endothelial dysfunction is thought to be of importance in the development of ocular vascular diseases....  相似文献   
78.
79.
First described in 1955 in New Jersey, epizootic haemorrhagic disease (EHD) causes a severe clinical disease in wild and domestic ruminants worldwide. Epizootic haemorrhagic disease outbreaks occur in deer populations each year from summer to late autumn. The etiological agent is EHD virus (EHDV) which is a double‐stranded segmented icosahedral RNA virus. EHD virus utilizes point mutations and reassortment strategies to maintain viral fitness during infection. In 2018, EHDV serotype 2 was predominantly detected in deer in Illinois. Whole genome sequencing was conducted for two 2018 EHDV2 isolates (IL41747 and IL42218) and the sequence analyses indicated that IL42218 was a reassortant between different serotypes whereas IL41747 was a genetically stable strain. Our data suggest that multiple strains contribute to outbreaks each year.  相似文献   
80.
Fibroepithelial polyps (FEPs) are common, benign intraoral lesions that tend to develop slowly at predictable sites, often in response to local irritation or trauma. Historical precedent often results in referral to oral and maxillofacial surgery (OMFS) departments for biopsy, often irrespective of symptoms, and histological assessment. OMFS and pathology services are struggling to cope with an increasing workload that will potentially lead to widespread delays to diagnosis and treatment. Over the past 20 years, clinical pathways and guidance have been developed to ensure that healthcare interventions, such as the removal of third molars, tonsils, skin tags, and benign moles, are evidence-based, have a net patient benefit, and ensure the best use of finite NHS resources. However, no such guidance exists for intraoral lesions and we regard this as an oversight. We analysed the removal of 682 FEPs over a seven-year period and report sensitivities of 92.4% for a “confirmed clinical suspicion of an FEP” and 99.7% for a “confirmed clinical suspicion of a benign diagnosis”. The incidence of non-benign disease was 0.3%. Primary care dentists should be able to diagnose and monitor FEPs and refer only if symptoms are serious or in high-risk patients or sites. Adopting this practice across the UK could free up to 1825 four-hour OMFS clinics, 405 hours of consultant histopathologists’ time, and recurring savings to the NHS estimated to be in the region of £620 000/annum. We believe that the removal of FEPs should be reclassified as an “intervention not normally funded”, and the time and resources put to better use treating patients with lesions of questionable pathology.  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