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   1659篇
  免费   81篇
  国内免费   18篇
耳鼻咽喉   7篇
儿科学   61篇
妇产科学   14篇
基础医学   228篇
口腔科学   24篇
临床医学   197篇
内科学   486篇
皮肤病学   40篇
神经病学   76篇
特种医学   84篇
外科学   141篇
综合类   90篇
预防医学   96篇
眼科学   13篇
药学   103篇
中国医学   3篇
肿瘤学   95篇
  2023年   9篇
  2022年   10篇
  2021年   32篇
  2020年   12篇
  2019年   33篇
  2018年   31篇
  2017年   23篇
  2016年   28篇
  2015年   26篇
  2014年   43篇
  2013年   49篇
  2012年   59篇
  2011年   78篇
  2010年   50篇
  2009年   52篇
  2008年   86篇
  2007年   137篇
  2006年   87篇
  2005年   63篇
  2004年   49篇
  2003年   60篇
  2002年   48篇
  2001年   42篇
  2000年   52篇
  1999年   46篇
  1998年   23篇
  1997年   22篇
  1996年   33篇
  1995年   19篇
  1994年   23篇
  1993年   12篇
  1992年   24篇
  1991年   30篇
  1990年   34篇
  1989年   46篇
  1988年   23篇
  1987年   20篇
  1986年   27篇
  1985年   18篇
  1984年   21篇
  1983年   14篇
  1981年   13篇
  1980年   8篇
  1979年   12篇
  1978年   8篇
  1976年   9篇
  1975年   8篇
  1974年   14篇
  1972年   8篇
  1966年   10篇
排序方式: 共有1758条查询结果,搜索用时 0 毫秒
41.
42.
The threat posed by emerging and re-emerging communicable diseases and, more recently, by the intentional release of infectious agents in a susceptible population, has been receiving considerable attention at the national and international levels. Public health efforts to strengthen disease detection, surveillance and control have been intensified. However, clinicians and clinical microbiology laboratories play an important role in the early detection of disease, the identification of the putative agent, and notification of the appropriate authorities. To be effective in this role, laboratories must be specially prepared to handle viral agents safely, and need, among other things, the appropriate rapid and sensitive diagnostic tests. In 1998 the European Network for Diagnostics of 'Imported' Viral Diseases (ENIVD) was established. ENIVD presently comprises, as permanent members, 44 expert laboratories in 21 European Union (EU) member states and 4 non-EU countries and is one of the networks on infectious diseases funded by the European Commission. ENIVD fulfils many of the important tasks required for the surveillance and control of imported, rare and emerging viral infections such as the exchange of expertise and the organisation of external quality assurance (EQA) programmes, both of which are needed to improve diagnostics. Here, we summarise the data generated by recent EQA activities focussed on the diagnostics of infections with hantavirus, dengue virus, filovirus, Lassa virus, orthopox virus and the SARS-coronavirus (SARS-CoV). These were carried out between 1999 and 2004 and involved 93 laboratories from 41 countries, including laboratories from additional countries outside of Europe. Particularly the EU-candidate countries and Eastern neighbouring countries will be invited to join the network in the near future. A public website is available at http://www.enivd.de.  相似文献   
43.
44.
45.
L‐asparaginase is an important drug in the treatment of childhood acute lymphoblastic leukaemia (ALL). Treatment is associated with several toxicities, including acute pancreatitis. Clinical course, presentation, re‐exposure to L‐asparginase after pancreatitis and risk of recurrent pancreatitis within an asparaginase‐intensive protocol has been poorly reported. Children (1–17 years) on the ongoing Nordic Society of Paediatric Haematology and Oncology (NOPHO) ALL2008 protocol with asparaginase‐associated pancreatitis (AAP) diagnosed between 2008 and 2012 were identified through the online NOPHO ALL toxicity registry. NOPHO ALL2008 includes eight or 15 doses of intramuscular pegylated L‐asparginase (PEG‐asparaginase) 1000 iu/m2/dose at 2–6 weeks intervals, with a total of 30 weeks of exposure to PEG‐asparaginase (clinicaltrials.gov no: NCT00819351). Of 786 children, 45 were diagnosed with AAP with a cumulative risk of AAP of 5·9%. AAP occurred after a median of five doses (range 1–13), and 11 d (median) from the latest administration of PEG‐Asparaginase. Thirteen patients developed pseudocysts (30%) and 11 patients developed necrosis (25%). One patient died from pancreatitis. Twelve AAP patients were re‐exposed to L‐asparginase, two of whom developed mild AAP once more, after four and six doses respectively. In conclusion, re‐exposure to PEG‐asparaginase in ALL patients with mild AAP seems safe.  相似文献   
46.
47.
There has been growing interest in Europe in recent years in the establishment and spread of invasive mosquitoes, notably the incursion of Aedes albopictus through the international trade in used tires and lucky bamboo, with onward spread within Europe through ground transport. More recently, five other non-European aedine mosquito species have been found in Europe, and in some cases populations have established locally and are spreading. Concerns have been raised about the involvement of these mosquito species in transmission cycles of pathogens of public health importance, and these concerns were borne out following the outbreak of chikungunya fever in Italy in 2007, and subsequent autochthonous cases of dengue fever in France and Croatia in 2010. This article reviews current understanding of all exotic (five introduced invasive and one intercepted) aedine species in Europe, highlighting the known import pathways, biotic and abiotic constraints for establishment, control strategies, and public health significance, and encourages Europe-wide surveillance for invasive mosquitoes.  相似文献   
48.
49.
牛津膝置换是使用最广泛的膝关节单髁置换(UKR)。牛津膝在37年前开始应用,拥有一个全匹配的活动衬垫,因而磨损率非常低。牛津膝最主要的使用指征是膝关节前内侧骨关节炎,这种病人至少占所有需要行膝关节置换术患者的50%。由于这一系统的设计特点,传统UKR的反指征,如年龄、活动量、肥胖、髌股关节损害和软骨钙质沉着症等对于牛津膝均不是反指征。与全膝关节置换(TKR)相比,牛津膝提供更快的康复、更好的功能、更大的活动度和更好的术后满意度,发生并发症更少、程度更轻,病残率和死亡率更低。一个持续超过30年的研究显示在90%的病例中,牛津膝为患者终生提供了优或良的临床结果,且不需要翻修。在最近15年,牛津膝通过微创手术入路植入,涉及6000多例使用该入路牛津膝置换的9个研究报道显示,10年生存率约95%。在许多这样的研究中,医生们在拟行膝关节置换的患者中约50%使用了牛津单髁膝置换。  相似文献   
50.

Background

The bacteria of the group Borrelia burgdorferi s.l. are the etiological agents of Lyme borreliosis in humans, transmitted by bites of ticks. Improvement of control measures requires a solid framework of the environmental traits driving its prevalence in ticks.

Methods

We updated a previous meta-analysis of the reported prevalence of Borrelia burgdorferi s.l. in questing nymphs of Ixodes ricinus with a literature search from January 2010–June 2017. This resulted in 195 new papers providing the prevalence of Bb for 926 geo-referenced records. Previously obtained data (878 records, years 2000–2010) were appended for modelling. The complete dataset contains data from 82,004 questing nymphs, resulting in 558 records of B. afzelii, 404 of B. burgdorferi s.s. (only 80 after the year 2010), 552 of B. garinii, 78 of B. lusitaniae, 61 of B. spielmanii, and 373 of B. valaisiana. We associated the records with explicit coordinates to environmental conditions and to a categorical definition of European landscapes (LANMAP2) looking for a precise definition of the environmental niche of the most reported species of the pathogen, using models based on different classification methods.

Results

The most commonly reported species are B. afzelii, B. garinii and B. valaisiana largely overlapping across Europe. Prevalence in ticks is associated with portions of the environmental niche. Highest prevalence occurs in areas of 280°–290° (Kelvin) of mean annual temperature experiencing a small amplitude, steady spring slope, together with high mean values and a moderate spring rise of vegetation vigor. Low prevalence occurs in sites with low and a noteworthy annual amplitude of temperature and the Normalized Difference Vegetation Index (colder areas with abrupt annual changes of vegetation). Models based on support vector machines provided a correct classification rate of the habitat and prevalence of 89.5%. These results confirm the association of prevalence of the three most commonly reported species of B. burgdorferi s.l. in Europe to parts of the environmental niche and provide a statistically tractable framework for analyzing trends under scenarios of climate change.
  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