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   406篇
  免费   16篇
  国内免费   22篇
耳鼻咽喉   1篇
儿科学   36篇
妇产科学   1篇
基础医学   20篇
口腔科学   9篇
临床医学   36篇
内科学   55篇
皮肤病学   8篇
神经病学   14篇
特种医学   120篇
外科学   24篇
综合类   29篇
预防医学   10篇
眼科学   27篇
药学   28篇
肿瘤学   26篇
  2023年   1篇
  2020年   1篇
  2019年   2篇
  2018年   5篇
  2017年   1篇
  2016年   2篇
  2015年   7篇
  2014年   6篇
  2013年   10篇
  2012年   2篇
  2011年   9篇
  2010年   9篇
  2009年   12篇
  2008年   14篇
  2007年   24篇
  2006年   25篇
  2005年   7篇
  2004年   11篇
  2003年   5篇
  2002年   5篇
  2001年   15篇
  2000年   4篇
  1999年   6篇
  1998年   34篇
  1997年   22篇
  1996年   26篇
  1995年   22篇
  1994年   19篇
  1993年   22篇
  1992年   8篇
  1991年   4篇
  1990年   10篇
  1989年   6篇
  1988年   7篇
  1987年   4篇
  1986年   11篇
  1985年   9篇
  1984年   7篇
  1983年   7篇
  1982年   7篇
  1981年   7篇
  1980年   13篇
  1979年   3篇
  1978年   4篇
  1977年   4篇
  1976年   4篇
  1975年   1篇
排序方式: 共有444条查询结果,搜索用时 15 毫秒
71.

Background:

Patellar dislocations are either due to superolateral contracture of the soft tissue or imbalance of the power between the vastus medialis (VM) and the vastus lateralis (VL). The imbalance of muscle power as an etiology of patellar dislocation has not been studied. Hence, we studied the recurrent, habitual and permanent dislocations of the patella with an electromyogram (EMG) of the vastus medialis, vastus lateralis, and pes anserinus, before and after realignment operations, to document the muscle imbalance and effectiveness of the realignment operation.

Materials and Methods:

An electromyographic investigation was carried out on the vastus medialis and vastus lateralis in nine recurrent, 20 habitual, and 13 permanent dislocations of the patella, before and after their realignment operations. Pes anserinus transposition, which acted as a medial stabilizer of the patella, was also investigated with an EMG study, to understand its role on patellar stability at 0°, 30°, 60°, 90°, 120°, 150°, and full flexion of the knee. The age of the patients varied from nine to 30 (mean 15) years. There were 24 males and 18 females. Twenty-six patellar dislocations were on the right and 16 were on the left side.

Results:

Electromyographic pictures reveal subnormal activity of the vastus medialis in all types of dislocations and similar activities of the vastus lateralis in permanent and habitual dislocations recorded pre operatively, which recovered to almost normal values postoperatively, at the mean one-year follow-up. Pes anserinus, which was used for medial stabilization of the patella after its realignment, maintained normal EMG activity before and after the operation.

Conclusion:

This study is significant for understanding the imbalance of muscle activities in patients with an unstable patella, which can be rectified without recurrence after pes anserinus transposition.  相似文献   
72.
Experiment 1 found that pretraining administration of electroconvulsive shock (ECS) attenuated ECS-induced amnesia of one-trial passive avoidance training in rats. Similarly, pretraining injections of cycloheximide (CXM) attenuated the amnestic effects of CXM at training. Experiment 2 demonstrated the ability of pretraining ECS to attenuate CXM-induced amnesia and pretraining CXM to attenuate ECS-induced amnesia. These studies join others in observing comparable behavioral effects of ECS-like amnestic agents and antimetabolite-like amnestic agents despite their different means of primary action. Collectively, these studies support the view that the two families of amnestic agents produce amnesia through a common mechanism.  相似文献   
73.
74.
Surgical innovation and pioneering are important for improving patient outcome, but can be associated with learning curves. Although learning curves in surgery are a recognized problem, the impact of surgical learning curves is increasing, due to increasing complexity of innovative surgical procedures, the rapid rate at which new interventions are implemented and a decrease in relative effectiveness of new interventions compared to old interventions. For minimally invasive esophagectomy(MIE), there is now robust evidence that implementation can lead to significant learning associated morbidity(morbidity during a learning curve, that could have been avoided if patients were operated by surgeons that have completed the learning curve). This article provides an overview of the evidence of the impact of learning curves after implementation of MIE. In addition, caveats for implementation and available evidence regarding factors that are important for safe implementation and safe pioneering of MIE are discussed.  相似文献   
75.
D1-receptor antagonism is known to impair rodent memory but also inhibits spontaneous exploration of stimuli to be remembered. Hypo-exploration could contribute to impaired memory by influencing event processing. In order to explore this effect, the D1 receptor antagonist, SCH23390, was administered to rats via routes that either did or did not affect spontaneous exploration: systemic or prelimbic administration, respectively. Effects were tested in spatial and non-spatial memory tasks selected for their requirements for self-initiated exploration of stimuli to be remembered in order to examine the effects on memory: cross-maze and object recognition task. Systemic administration reduced spatial exploration in cross-maze as well as in an open field test, and also reduced object exploration. Spatial (hippocampus-dependent) short-term memory was inhibited in the cross-maze and non-spatial short-term object retention was also impaired. In contrast to these systemic effects, bilateral injections of SCH23390 into the prelimbic cortices altered neither spatial nor object exploration, but did inhibit short-term memory in both cross-maze and object recognition task. Therefore, the inhibiting effects of SCH23390 on both spatial and non-spatial memory were not mediated indirectly via reduced exploration of stimuli to be remembered, but through antagonism of a prelimbic D1-R function that is directly involved in memory formation. Finally, a cooperative regulation of spatial exploration between D1-R and mGlu5 was indicated by a synergistic effect of the antagonists SCH23390 and MPEP.  相似文献   
76.

Introduction  

The aim of this study was to develop and validate a prognostication model to predict overall and breast cancer specific survival for women treated for early breast cancer in the UK.  相似文献   
77.
78.
Esophagectomy,the surgical removal of all or part of the esophagus,is a surgical procedure that is associated with high morbidity and mortality.Pulmonary complications are an especially important postoperative problem.Therefore,many perioperative strategies to prevent pulmonary complications after esophagectomy have been investigated and introduced in daily clinical practice.Here,we review these strategies,including improvement of patient performance and technical advances such as minimally invasive surgery that have been implemented in recent years.Furthermore,interventions such as methylprednisolone,neutrophil elastase inhibitor and epidural analgesia,which have been shown to reduce pulmonary complications,are discussed.Benefits of the commonly applied routine nasogastric decompression,delay of oral intake and prophylactic mechanical ventilation are unclear,and many of these strategies are also evaluated here.Finally,we will discuss recent insights and new developments aimed to improve pulmonary outcomes after esophagectomy.  相似文献   
79.
目的 用重组日本血吸虫22kD表膜蛋白(rSj22)免疫水牛,检测特异性IgG抗体的应答水平,并观察抗血吸虫的保护效果。方法 用抗原(rSj22)加佐剂(Quil-A)肌肉注射免疫水牛,以1000条日本血吸虫尾蚴攻击感染,感染后55d剖杀,计算减虫和减卵率,用免疫印斑和ELISA方法测定抗体反应。结果 免疫组每头牛血清均能特异地识别Quil-A对照组相比,减虫率仅8.5%肝卵EPG减少12.3%,粪卵EPG减少26.8%,但均无统计学意义,结论 用rSj22kD抗原免疫水牛诱导的特异性IgG抗体不能发挥免疫保护作用。  相似文献   
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