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   6401篇
  免费   461篇
  国内免费   15篇
耳鼻咽喉   49篇
儿科学   201篇
妇产科学   155篇
基础医学   691篇
口腔科学   97篇
临床医学   947篇
内科学   1274篇
皮肤病学   64篇
神经病学   589篇
特种医学   132篇
外科学   994篇
综合类   93篇
一般理论   27篇
预防医学   703篇
眼科学   63篇
药学   375篇
中国医学   9篇
肿瘤学   414篇
  2023年   70篇
  2022年   96篇
  2021年   296篇
  2020年   138篇
  2019年   257篇
  2018年   278篇
  2017年   166篇
  2016年   157篇
  2015年   158篇
  2014年   227篇
  2013年   323篇
  2012年   431篇
  2011年   479篇
  2010年   226篇
  2009年   206篇
  2008年   337篇
  2007年   312篇
  2006年   276篇
  2005年   289篇
  2004年   263篇
  2003年   219篇
  2002年   196篇
  2001年   86篇
  2000年   79篇
  1999年   54篇
  1998年   50篇
  1997年   39篇
  1996年   41篇
  1995年   39篇
  1994年   23篇
  1993年   26篇
  1992年   65篇
  1991年   68篇
  1990年   78篇
  1989年   58篇
  1988年   50篇
  1987年   67篇
  1986年   69篇
  1985年   36篇
  1984年   34篇
  1983年   37篇
  1982年   29篇
  1981年   25篇
  1979年   49篇
  1978年   30篇
  1977年   26篇
  1976年   25篇
  1973年   23篇
  1971年   22篇
  1969年   20篇
排序方式: 共有6877条查询结果,搜索用时 15 毫秒
111.
ObjectivesIntravenous (IV) tissue plasminogen activator (tPA) should be given to patients with acute ischemic stroke (AIS) and avoided in stroke mimics (SM). Select use of emergency brain magnetic resonance imaging (eMRI-brain) in stroke-alerts aids diagnosis, but accepted utilization criteria for eMRI-brain do not currently exist. We developed criteria for eMRI-brain and report the yield of eMRI-brain in stroke-alert patients.Materials and MethodsWe developed three history-based criteria for performing eMRI-brain during stroke-alerts: (1) history of previous similar deficits, (2) change in consciousness at onset of symptoms, (3) symptom presentation consistent with migraine aura. We then performed a retrospective chart review of patients who presented as a stroke-alert over a 5-year period and determined how these criteria affected administration of IV tPA to AIS and SM patients.ResultsAmong 3,512 stroke-alerts, 230 (8.1%) patients met our criteria for eMRI-brain exams: 217 (92.6%) had SM and 17 (7.4%) had AIS. Our IV tPA decision-making analysis showed that based on eMRI-brain IV tPA was less frequently administered to SM patients (PCC-0.841, p=0.036) with less failures to administer IV tPA to patients with AIS (PCC -0.907, p-value=0.013, Pearson correlation coefficient). No patients became ineligible for IV tPA due to MRI-related time delays.ConclusionsOur history based criteria for performing eMRI-brain during stroke-alerts show a high yield of stroke mimics. Selective eMRI-brain improves decision-making accuracy regarding IV tPA administration.  相似文献   
112.
113.
114.
The proprotein convertases (PCs) furin and PACE4 process numerous substrates involved in tumor growth, invasion, and metastasis. We have previously shown that PCs increase the susceptibility to chemical skin carcinogenesis. Because of the human relevancy of UV radiation in the etiopathogenesis of human skin cancer, we investigated whether or not transgenic mice overexpressing either furin alone or both furin and PACE4 show increased susceptibility to UV carcinogenesis. After backcrossing our previously described furin and PACE4 transgenic lines, targeted to the epidermis, into a SKH-1 background, we exposed both single and double transgenic mice to UV radiation for 34 weeks. The results showed an increase in squamous cell carcinoma (SCC) multiplicity of approximately 70% in the single furin transgenic mouse line SF47 (P < .002) and a 30% increase in the other single transgenic line SF49 when compared to wild-type (WT) SKH-1 mice. Interestingly, there was also an increase in the percentage of high histologic grade SCCs in the transgenic lines compared to the WT mice, i.e., WT = 9%, SF47 = 15%, and SF49 = 26% (P < .02). Targeting both furin and PACE4 to the epidermis in double transgenic mice did not have an additive effect on tumor incidence/multiplicity but did enhance the tumor histopathologic grade, i.e., a significant increase in higher grade SCCs was seen in the bigenic mouse line SPF47 (P < .02). Thus, we observed an increased susceptibility to UV in single furin transgenic mice that was not substantially enhanced in the double furin/PACE4 transgenic mice.  相似文献   
115.
In March 2013, the National Institute of Allergy and Infectious Diseases and the Bill and Melinda Gates Foundation co-sponsored a meeting entitled “Schistosomiasis Elimination Strategy and Potential Role of a Vaccine in Achieving Global Health Goals” to discuss the potential role of schistosomiasis vaccines and other tools in the context of schistosomiasis control and elimination strategies. It was concluded that although schistosomiasis elimination in some focal areas may be achievable through current mass drug administration programs, global control and elimination will face several significant scientific and operational challenges, and will require an integrated approach with other, additional interventions. These challenges include vector (snail) control; environmental modification; water, sanitation, and hygiene; and other future innovative tools such as vaccines. Defining a clear product development plan that reflects a vaccine strategy as complementary to the existing control programs to combat different forms of schistosomiasis will be important to develop a vaccine effectively.  相似文献   
116.
Pancreatic cancer is the fourth leading cause of cancer deaths in the USA. Although some patients will present with premalignant pancreatic lesions (i.e., intraductal papillary mucinous neoplasms) or localized tumors amenable to curative resection, the majority of patients will unfortunately present with technically unresectable or metastatic disease. This review of the recent medical literature will discuss the optimal work-up and management of premalignant pancreatic lesions and the surgical management of localized, borderline resectable, and locally advanced (i.e., unresectable) pancreatic tumors. It will focus on new criteria used to define surgical “resectability,” the significance and clinical impact of surgical margins, the role of multimodality therapy in the management of patients with borderline resectable or locally advanced tumors, the role of surgery for local or distant recurrence, and minimally invasive surgical approaches.  相似文献   
117.
118.
119.
120.
Objective. To assess the impact of a multipreceptor approach to facilitating topic discussions on students'' knowledge and confidence in clinical decision-making during an ambulatory care advanced pharmacy practice experiences (APPEs).Design. Faculty members with relevant expertise and experience facilitated discussions with fourth-year doctor of pharmacy (PharmD) students regarding 7 ambulatory care topics. A student self-assessment survey and knowledge-assessment instrument was administered before and after discussions.Assessment. Students'' examination scores increased significantly from 59.1% ± 13.9% at baseline to 76.5% ± 12.6% at the end of the 5-week experience (p<0.001). The majority of participants were comfortable making therapeutic decisions regarding medication use as it related to all discussion topics except heart failure.Conclusions. Participation in topic discussions led by faculty members with expertise and experience for each ambulatory care topic was associated with a significant improvement in knowledge-assessment scores.  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