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   5559篇
  免费   355篇
  国内免费   13篇
耳鼻咽喉   104篇
儿科学   280篇
妇产科学   79篇
基础医学   582篇
口腔科学   80篇
临床医学   445篇
内科学   1230篇
皮肤病学   103篇
神经病学   349篇
特种医学   125篇
外科学   1037篇
综合类   90篇
一般理论   3篇
预防医学   327篇
眼科学   219篇
药学   503篇
中国医学   19篇
肿瘤学   352篇
  2023年   51篇
  2022年   101篇
  2021年   212篇
  2020年   125篇
  2019年   170篇
  2018年   205篇
  2017年   133篇
  2016年   169篇
  2015年   170篇
  2014年   245篇
  2013年   267篇
  2012年   374篇
  2011年   368篇
  2010年   231篇
  2009年   203篇
  2008年   329篇
  2007年   378篇
  2006年   376篇
  2005年   308篇
  2004年   287篇
  2003年   263篇
  2002年   213篇
  2001年   90篇
  2000年   57篇
  1999年   49篇
  1998年   51篇
  1997年   28篇
  1996年   40篇
  1995年   17篇
  1994年   22篇
  1993年   25篇
  1992年   25篇
  1991年   28篇
  1990年   22篇
  1989年   25篇
  1988年   34篇
  1987年   31篇
  1986年   23篇
  1985年   14篇
  1984年   19篇
  1983年   12篇
  1982年   8篇
  1981年   9篇
  1980年   12篇
  1977年   9篇
  1975年   13篇
  1973年   11篇
  1972年   9篇
  1971年   8篇
  1970年   17篇
排序方式: 共有5927条查询结果,搜索用时 0 毫秒
71.
Apart from their existence as medical curiosities, anatomic variants also double as diagnostic dilemmas. In the heart, more than in any other location in the body, misinterpretation of normal anatomic variants as pathologic entities can have a profound impact on treatment decisions and clinical consequences. Echocardiography is an easily accessible tool these days and is used routinely in most cardiac evaluations. Thus it becomes imperative for the echocardiographer to be cognizant of normal anatomic variants. Furthermore, echocardiographic findings should always be evaluated in their proper clinical context and diagnoses should never be entertained in a clinical vacuum. The literature is replete with numerous case reports and vignettes on these fascinating structures but is lacking in a formal review of normal anatomic variants. In this article, we have attempted a systemic review of normal variants, their embryologic origins, echocardiographic characteristics, and common pitfalls encountered in their evaluation.  相似文献   
72.
Venous thromboembolism (VTE) has long been considered a disease that affects predominantly white populations, a misconception resulting from a paucity of epidemiological data from non-Western countries, and the low incidence of hereditary thrombophilia in those of non-Caucasian background. Over the last decade, interest has grown in this area with the emergence of evidence that VTE is as prevalent, if not more so, in the black population and is also common in Asian groups. Much is still to be learned, as our current knowledge of hereditary thrombophilia and acquired risk factors do not fully explain the risk of VTE in non-Caucasian groups. This review summarises the current understanding of ethnic variation in VTE and highlights the need for further research in this area.  相似文献   
73.
We prospectively and blindly assessed the diagnostic and prognostic impact of implementation of the European Society of Cardiology/American College of Cardiology recommendations for redefinition of myocardial infarction (MI) in an unselected cohort of patients with suspected cardiac chest pain, with particular attention to prespecified clinical groups. All patients admitted to our institute with suspected cardiac chest pain were enrolled. Physicians provided usual care using serial electrocardiograms/creatine kinase (CK)/aspartate transaminase according to World Health Organization (WHO) criteria for MI, while blinded to additional measurements of cardiac troponin T (cTnT) and CK-MB mass. After discharge, diagnoses based on WHO and new criteria were compared, and major adverse cardiac events monitored for 6 months. Implementation of the new recommendations classified an additional 26.1% of patients as having MI compared with WHO criteria, and produced an overall diagnostic alteration in 11.5%. Two thirds of the additional patients with MI were previously diagnosed with unstable angina, whereas one third had "other cardiac" or "noncardiac" diagnoses. A similar MI cohort to the cTnT diagnosis was identified using a CK-MB mass discriminator value of 5 microg/L, but not 10 microg/L. The 6-month prognosis was similar in patients diagnosed with MI by new (cTnT) and WHO criteria, with the new criteria thus identifying a further high-risk cohort in the WHO negative group. In our cohort, the new Joint European Society of Cardiology/American College of Cardiology recommendations identify one fourth more patients as having MI. The 6-month prognosis of those patients reclassified as having MI was similar to those diagnosed with MI by both criteria.  相似文献   
74.
Past few decades have witnessed the dawn of new diseases in which cancer is a major problem and the race ensued to eradicate cancer by charting out various effective therapeutic regimens. Circumventing resistance issues and combating the toxicity and selectivity problems are matter-of-concern in cancer treatment. Persistent failure to ensure complete remission and eradication of cancer instigated the researchers to exploit the strategies of combining pharmacophores as targeted therapeutic agents. Momentous improvement in the pharmacokinetic as well as pharmacodynamic profile resulting in the enhancement of bioavailability was seen with the introduction of these pharmacophores. The scope of molecular hybridization can be clearly exemplified through the US-FDA approved estramustine and others such as CUDC-101, CBLC-137, PLX3397, E-3810, and CUDC-907 that are currently in different phases of clinical trials. This review seeks to highlight and discuss anti-proliferative activity of some important hybrid, dual, and multi-targeted pharmacophores reported to date along with their designs, structure activity relationships, scope, and limitations. Further, an emphasis has been made to summarize US-FDA approved as well as drugs currently undergoing clinical trials of anticancer drug development.  相似文献   
75.
76.
77.
78.
White matter abnormalities on magnetic resonance imaging (MRI) are associated with dementia and include white matter hyperintensities (WMH; also termed leukoaraiosis) and visible perivascular spaces (PVS). We review the potential role of impaired drainage of interstitial fluid in the pathogenesis of WMH and PVS. Whereas the volume of extracellular space in the grey matter is tightly controlled, fluid accumulates and expands the extracellular spaces of the white matter in acute hydrocephalus, vasogenic edema and WMH. Although there are no conventional lymphatic vessels in the brain, there is very effective lymphatic drainage for fluid and solutes along restricted pathways in the basement membranes of cerebral capillaries and arteries in young individuals. Lymphatic drainage of the brain is impaired with age and in association with apolipoprotein E ε4, risk factors for Alzheimer's disease and cerebral amyloid angiopathy (CAA). Deposition of proteins in the lymphatic drainage pathways in the walls of cerebral arteries with age is recognized as protein elimination failure angiopathy (PEFA), as in CAA and cerebral autosomal dominant arteriopathy and leukoencephalopathy (CADASIL). Facilitating perivascular lymphatic drainage from the aging brain may play a significant role in the prevention of CAA, WMH and Alzheimer's disease and may enhance the efficacy of immunotherapy for Alzheimer's disease.  相似文献   
79.
80.
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