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   4347212篇
  免费   348453篇
  国内免费   14681篇
耳鼻咽喉   60299篇
儿科学   139414篇
妇产科学   114197篇
基础医学   666496篇
口腔科学   117956篇
临床医学   396855篇
内科学   790166篇
皮肤病学   107714篇
神经病学   368173篇
特种医学   169434篇
外国民族医学   754篇
外科学   656020篇
综合类   121262篇
现状与发展   24篇
一般理论   2614篇
预防医学   360279篇
眼科学   100872篇
药学   307499篇
  26篇
中国医学   11934篇
肿瘤学   218358篇
  2021年   56121篇
  2020年   35803篇
  2019年   58783篇
  2018年   74350篇
  2017年   56965篇
  2016年   63078篇
  2015年   76043篇
  2014年   110242篇
  2013年   175764篇
  2012年   124150篇
  2011年   128872篇
  2010年   125831篇
  2009年   127569篇
  2008年   115100篇
  2007年   122364篇
  2006年   131190篇
  2005年   125271篇
  2004年   126582篇
  2003年   116793篇
  2002年   106040篇
  2001年   166934篇
  2000年   162013篇
  1999年   148665篇
  1998年   71655篇
  1997年   67602篇
  1996年   65621篇
  1995年   61041篇
  1994年   54965篇
  1993年   51009篇
  1992年   106612篇
  1991年   101377篇
  1990年   97236篇
  1989年   94810篇
  1988年   87138篇
  1987年   85305篇
  1986年   80193篇
  1985年   78351篇
  1984年   65393篇
  1983年   58195篇
  1982年   47187篇
  1981年   43855篇
  1980年   41072篇
  1979年   55101篇
  1978年   44753篇
  1977年   39978篇
  1976年   36837篇
  1975年   36805篇
  1974年   39609篇
  1973年   37749篇
  1972年   35360篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
Psoriasis is a common chronic inflammatory skin disease, affecting about 3% of the general population and approximately 2.5 million people in France, where this study took place. The genital area may be affected, however prevalence is poorly understood, meaning we do not know exactly how commonly this occurs. While it affects quality of life, genital psoriasis is under-recognized, probably due to the reluctance of patients to discuss genital involvement and sexual quality of life. The aims of this study, called the GENIPSO study, were to determine the prevalence of genital psoriasis, its clinical characteristics (its symptoms), whether it is associated with a particular type of psoriasis, and its impact on quality of life. The study included 776 adults seeing their doctor for psoriasis between November 2016 and March 2017. Among them, 336 (43.2%) had genital psoriasis. All these patients were aware that they had psoriasis on their genitals (genital lesions) but only 135 (40%) had already had a genital medical examination. Genital lesions were associated with (linked to) male gender, more severe psoriasis, first developing psoriasis when aged over 20 years, psoriasis of the skin folds, psoriasis on the scalp, nail and external auditory (ear) canal, but they were not associated with obesity or psoriatic arthritis. Itching was the main symptom. Genital psoriasis was associated with reduced quality of life and sexual health. The study found that genital psoriasis has a high prevalence in patients seeing their doctors about their psoriasis generally, it affects quality of life and should be better taken into account by dermatologists for the best possible care for patients.  相似文献   
994.
995.
996.
Despite a population of nearly 60 million, there is currently not a single interventional radiologist in Tanzania. Based on an Interventional Radiology (IR) Readiness Assessment, the key obstacles to establishing IR in Tanzania are the lack of training opportunities and limited availability of disposable equipment. An IR training program was designed and initiated, which relies on US-based volunteer teams of IR physicians, nurses, and technologists to locally train radiology residents, nurses, and technologists. Preliminary results support this strategy for addressing the lack of training opportunities and provide a model for introducing IR to other resource-limited settings.  相似文献   
997.
998.
999.
Several regulatory bodies have agreed that low-dose radiation used in medical imaging is a weak carcinogen that follows a linear, non-threshold model of cancer risk. While avoiding radiation is the best course of action to mitigate risk, computed tomography (CT) scans are often critical for diagnosis. In addition to the as low as reasonably achievable principle, a more concrete method of dose reduction for common CT imaging exams is the use of a diagnostic reference level (DRL). This paper examines Canada's national DRL values from the recent CT survey and compares it to published provincial DRLs as well as the DRLs in the United Kingdom and the United States of America for the 3 most common CT exams: head, chest, and abdomen/pelvis. Canada compares well on the international scale, but it should consider using more electronic dose monitoring solutions to create a culture of dose optimization.  相似文献   
1000.
Background & Aims: Impaired message-structure mapping results in deficits in both sentence production and comprehension in aphasia. Structural priming has been shown to facilitate syntactic production for persons with aphasia (PWA). However, it remains unknown if structural priming is also effective in sentence comprehension. We examined if PWA show preserved and lasting structural priming effects during interpretation of syntactically ambiguous sentences and if the priming effects occur independently of or in conjunction with lexical (verb) information.

Methods & Procedures: Eighteen PWA and 20 healthy older adults (HOA) completed a written sentence-picture matching task involving the interpretation of prepositional phrases (PP; the chef is poking the solider with an umbrella) that were ambiguous between high (verb modifier) and low attachment (object noun modifier). Only one interpretation was possible for prime sentences, while both interpretations were possible for target sentences. In Experiment 1, the target was presented immediately after the prime (0-lag). In Experiment 2, two filler items intervened between the prime and the target (2-lag). Within each experiment, the verb was repeated for half of the prime-target pairs, while different verbs were used for the other half. Participants’ off-line picture matching choices and response times were measured.

Results: After reading a prime sentence with a particular interpretation, HOA and PWA tended to interpret an ambiguous PP in a target sentence in the same way and with faster response times. Importantly, both groups continued to show this priming effect over a lag (Experiment 2), although the effect was not as reliable in response times. However, neither group showed lexical (verb-specific) boost on priming, deviating from robust lexical boost seen in the young adults of prior studies.

Conclusions: PWA demonstrate abstract (lexically-independent) structural priming in the absence of a lexically-specific boost. Abstract priming is preserved in aphasia, effectively facilitating not only immediate but also longer-lasting structure-message mapping during sentence comprehension.  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