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   745篇
  免费   69篇
  国内免费   13篇
耳鼻咽喉   1篇
儿科学   72篇
妇产科学   9篇
基础医学   89篇
口腔科学   13篇
临床医学   75篇
内科学   173篇
皮肤病学   6篇
神经病学   64篇
特种医学   81篇
外科学   81篇
综合类   20篇
一般理论   6篇
预防医学   73篇
眼科学   3篇
药学   28篇
肿瘤学   33篇
  2021年   13篇
  2019年   7篇
  2018年   7篇
  2017年   14篇
  2016年   11篇
  2015年   11篇
  2014年   21篇
  2013年   24篇
  2012年   17篇
  2011年   22篇
  2010年   17篇
  2009年   16篇
  2008年   20篇
  2007年   23篇
  2006年   16篇
  2005年   22篇
  2004年   19篇
  2003年   23篇
  2002年   14篇
  2001年   13篇
  2000年   19篇
  1999年   18篇
  1998年   26篇
  1997年   18篇
  1996年   18篇
  1995年   16篇
  1994年   14篇
  1993年   13篇
  1992年   11篇
  1991年   11篇
  1990年   18篇
  1989年   15篇
  1988年   20篇
  1987年   15篇
  1986年   13篇
  1985年   18篇
  1984年   13篇
  1983年   23篇
  1982年   13篇
  1981年   9篇
  1980年   7篇
  1979年   14篇
  1977年   12篇
  1976年   7篇
  1975年   11篇
  1974年   12篇
  1973年   20篇
  1972年   9篇
  1970年   8篇
  1967年   17篇
排序方式: 共有827条查询结果,搜索用时 15 毫秒
1.
Using data on waterfowl band recoveries, we identified spatially explicit hotspots of concentrated waterfowl movement to predict occurrence and spatial spread of a novel influenza A virus (clade 2.3.4.4) introduced from Asia by waterfowl from an initial outbreak in North America in November 2014. In response to the outbreak, the hotspots of waterfowl movement were used to help guide sampling for clade 2.3.4.4 viruses in waterfowl as an early warning for the US poultry industry during the outbreak . After surveillance sampling of waterfowl, we tested whether there was greater detection of clade 2.3.4.4 viruses inside hotspots. We found that hotspots defined using kernel density estimates of waterfowl band recoveries worked well in predicting areas with higher prevalence of the viruses in waterfowl. This approach exemplifies the value of ecological knowledge in predicting risk to agricultural security.  相似文献   
2.
PURPOSE: Concern over stigma as a consequence of genetic testing has grown in response to the recent increase in genetic research and testing resulting from the Human Genome Project. However, whether a genetic or hereditary basis necessarily confers a stigma to a condition remains unexamined. METHODS: We performed a qualitative interview study with 86 individuals with one of four conditions: deafness or hearing loss, breast cancer, sickle cell disease, and cystic fibrosis. The first two groups were divided approximately between people who ascribed their conditions to a genetic or hereditary cause and those who did not. RESULTS: Respondents interpreted genetic or hereditary causes and nongenetic causes in a variety of ways. Subjects with breast cancer reported the most consistently negative interpretation of genetic cause. This response concerned future ill health, not an enduring sense of stigma. Deaf and hard of hearing subjects provided the most consistently positive comments about a genetic or hereditary basis to their condition, casting familial hearing loss as a vital component of group and individual identity. Respondents with sickle cell disease and cystic fibrosis offered similar and positive interpretations of the genetic cause of their condition insofar as it meant their conditions were not contagious. CONCLUSIONS: Although some subjects report feeling stigmatized as a result of their condition, this stigmatization is not uniformly associated with the condition's cause, genetic or otherwise. Instead, stigma emerges from a variety of sources in the context of the lived experience of a particular condition.  相似文献   
3.
Steroidal neuromuscular blocking agents (NMBAs), such as rocuronium, are widely used in clinical anesthesia and emergency medicine to facilitate endotracheal intubation and artificial ventilation and to allow surgical access to body cavities. Reversal of neuromuscular blockade is important for the acceleration of patient recovery and prevention of postoperative residual neuromuscular blockade and reduces the incidence of severe morbidity and mortality associated with anesthesia management. Sugammadex is the first selective relaxant binding agent (SRBA) and has been designed to reverse the steroidal neuromuscular blocking drug rocuronium. Encapsulation of the rocuronium molecule by sugammadex results in a rapid decrease in free rocuronium in the plasma and subsequently at the nicotinic receptor at the motor endplate. After encapsulation, rocuronium is not available to bind to the nicotinic receptor in the neuromuscular junction. This promotes the liberation of acetylcholine receptors, and muscle activity reappears. This new concept of reversal of neuromuscular block induced by rocuronium (or vecuronium) led to impressive results in animal and phase 1 and 2 studies. Sugammadex is currently in phase 3 clinical studies and may be commercially available by 2008.  相似文献   
4.
Abdominal trauma and diagnostic peritoneal lavage revisited   总被引:3,自引:0,他引:3  
  相似文献   
5.
Irving  HD; Burbridge  BE 《Radiology》1989,173(1):91-92
In vitro and in vivo precipitation of iodinated contrast agents when ioxaglate and papaverine are given together has been reported. To verify these reports and to investigate other medications not previously tested, the authors analyzed mixtures of contrast agents and medications in vitro with a light spectrophotometer and observed them for visible precipitates for up to 120 minutes. Previously reported incompatibilities between ionic or low-osmolality contrast media and medications were verified, and several new incompatibilities were discovered. No incompatibilities were found when the drugs tested were mixed with the new nonionic contrast media.  相似文献   
6.
7.
Women wish to continue to be sexually active long after their desire to bear children. The risks associated with unintended pregnancy easily can be avoided by providing women with information about, and access to, contraceptives that are safe and effective. Because fertility naturally declines with age, different contraceptives may be more suitable for women toward the end of their reproductive years than were appropriate at periods of peak fertility. This article discusses the risks and benefits of various contraceptives for midlife women and the implications of this information on nursing practice.  相似文献   
8.
9.
Summary The induction time for amorphous calcium phosphate (ACP) phase transformation was monitored at pH 7.4 and T=25°C with [Ca2+]0=[PO4]0=4.0×10−3 M, as a function of added crystal growth inhibitors Mg2+, Sr2+, Zn2+, pyrophosphate (PP), and tripolyphosphate (TPP). Metal ions increase the induction time for the initiation of the phase change reaction in the order Zn2+<Sr2+<Mg2+. For polyphosphates it was observed that both PP and TPP are potent inhibitors with TPP more effective than PP as expected. The combination of Mg2+ or Sr2+ and PP or TPP leads to a synergistic delay in the onset of the phase conversion. The greatest inhibition was observed for Mg2+ and TPP. Reaction solutions containing 2.0×10−4 M Mg2+ and 4.0×10−5 M TPP resulted in a 90% increase in the induction time over what would be anticipated from an additive effect from these species.  相似文献   
10.
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