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   312篇
  免费   29篇
耳鼻咽喉   11篇
儿科学   4篇
妇产科学   18篇
基础医学   48篇
口腔科学   1篇
临床医学   27篇
内科学   85篇
皮肤病学   20篇
神经病学   11篇
特种医学   5篇
外科学   54篇
预防医学   26篇
眼科学   6篇
药学   10篇
肿瘤学   15篇
  2023年   2篇
  2022年   6篇
  2021年   7篇
  2020年   4篇
  2019年   24篇
  2018年   13篇
  2017年   10篇
  2016年   11篇
  2015年   5篇
  2014年   13篇
  2013年   19篇
  2012年   13篇
  2011年   17篇
  2010年   19篇
  2009年   14篇
  2008年   14篇
  2007年   17篇
  2006年   15篇
  2005年   7篇
  2004年   14篇
  2003年   11篇
  2002年   6篇
  2001年   4篇
  2000年   12篇
  1999年   8篇
  1998年   6篇
  1997年   6篇
  1996年   2篇
  1995年   1篇
  1993年   1篇
  1992年   3篇
  1991年   5篇
  1990年   7篇
  1989年   1篇
  1988年   7篇
  1987年   3篇
  1986年   2篇
  1983年   1篇
  1982年   1篇
  1981年   2篇
  1980年   1篇
  1979年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
  1970年   3篇
排序方式: 共有341条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
IntroductionThe aim of this study was to assess several air-pressure settings for MI–E to determine their effect on peak cough flow (PCF), and to compare the best pressures with those are more common used in the literature (±40 cmH2O) in patients with neuromuscular disorders (NMD).MethodsAdults with NMD in whom MI–E was indicated were recruited. Assisted PCF was measured by an external pneumotachograph. The protocol included 9 PCF measures per patient: 1 baseline (non-assisted), 4 with increasing inspiratory pressures without negative pressure (10, 20, 30 and 40 cmH2O or maximum tolerated), and then 4 adding expiratory pressures (?10, ?20, ?30 and ?40 cmH2O or maximum tolerated) with maximum inspiratory pressure previously achieved.ResultsTwenty one patients were included, 61% with amyotrophic lateral sclerosis (ALS). Mean PCFs with recommended pressures (±40 cmH2O) were lower than the scored in the individualized steps of the titration protocol (197.7 ± 67 l/min vs 214.2 ± 60 l/min, p < 0.05). Regarding subgroups, mean PCFmax values in ALS patients with bulbar symptoms were significantly higher than those achieved with recommended pressures (163.6 ± 80 vs 189 ± 66 l/min, p < 0.05).ConclusionThe PCFmax obtained with the protocol did not always match the recommended settings. It may be advisable to perform MI–E titration assessed by non-invasive PCF monitoring in patients with NMD, especially in ALS with bulbar involvement to improve the therapy detecting airway collapse induced by high pressures.  相似文献   
6.
The coming into force of Directive 2001/20/EC represented a step forward in harmonising clinical trial regulation in European countries, guaranteeing a uniform protection of subjects participating in clinical research across Europe. However, it led to a disproportionate increase in the bureaucratization, and thus, it became evident that procedures needed to be simplified without detriment to patient’s safety. Thus, Regulation 536/2014, that repealed Directive 2001/20/EC, with the aim of decreasing the growing bureaucratization and stimulating clinical research in Europe, established simplified procedures, such as regulating a common procedure for authorising trials in Europe, the institution of strict assessment timelines, or the definition of new concepts, such as “low-intervention clinical trial”. The legal form of a Regulation allowed the norm to be directly applied to Member States without the need for transposition. By means of the new Royal Decree, the national legislation is adapted to make the application of the regulation feasible and it allows the development of the aspects that the Regulation leaves to national legislation. Both documents seek to stimulate clinical research with medicinal products to foster knowledge, facilitate transparency, and reinforce subjects’ safety. This will surely be the case, but with this revision, we will look at the novelties and key aspects that are most relevant to investigators and we will analyse the consequences for all parties involved in clinical research.  相似文献   
7.
8.
In this study we test the hypothesis that mechanically elastic regions in a virus particle (or large biomolecular complex) must coincide with conformationally dynamic regions, because both properties are intrinsically correlated. Hypothesis-derived predictions were subjected to verification by using 19 variants of the minute virus of mice capsid. The structural modifications in these variants reduced, preserved, or restored the conformational dynamism of regions surrounding capsid pores that are involved in molecular translocation events required for virus infectivity. The mechanical elasticity of the modified capsids was analyzed by atomic force microscopy, and the results corroborated every prediction tested: Any mutation (or chemical cross-linking) that impaired a conformational rearrangement of the pore regions increased their mechanical stiffness. On the contrary, any mutation that preserved the dynamics of the pore regions also preserved their elasticity. Moreover, any pseudo-reversion that restored the dynamics of the pore regions (lost through previous mutation) also restored their elasticity. Finally, no correlation was observed between dynamics of the pore regions and mechanical elasticity of other capsid regions. This study (i) corroborates the hypothesis that local mechanical elasticity and conformational dynamics in a viral particle are intrinsically correlated; (ii) proposes that determination by atomic force microscopy of local mechanical elasticity, combined with mutational analysis, may be used to identify and study conformationally dynamic regions in virus particles and large biomolecular complexes; (iii) supports a connection between mechanical properties and biological function in a virus; (iv) shows that viral capsids can be greatly stiffened by protein engineering for nanotechnological applications.  相似文献   
9.

Tic disorders have a strong male predominance, with a male-to-female ratio of 4:1 in Tourette syndrome (TS) and 2:1 in persistent tic disorders. In other neurodevelopmental conditions, such as autism spectrum disorder (ASD) and attention-deficit/hyperactivity disorder (ADHD), the disparity in sex distribution has been partially related to differences in symptom presentation between males and females. In tic disorders, however, little research has been conducted on this topic, probably due to the limited access to large samples with a significant proportion of females. The aim of this study was to describe sex differences in the clinical presentation of tic disorders in children and adolescents in one of the largest pediatric samples with TS/persistent tic disorders (n = 709, 23.3% females) recruited as part of the European Multicenter Tics in Children Study (EMTICS). Validated measures assessed the severity of tics and comorbid psychiatric symptoms. Using mixed-effect models, we found that sex had a significant influence on the severity of tics, ADHD symptoms, ASD symptoms, and emotional problems. Males had more severe symptoms than females, except for emotional problems. We also observed a statistically significant interaction between sex and age on the severity of tics and compulsions, with females showing higher symptom severity with increasing age than males. These findings indicate that the clinical presentation of TS/persistent tic disorders varies with sex. Males seem to exhibit a more noticeable pattern of clinical symptoms at a younger age that may contribute to their earlier detection in comparison to females.

  相似文献   
10.
Introduction: Effective resuscitation with human albumin solutions is achieved with less fluid than with crystalloid solutions. However, the role of albumin in today’s critical care unit is also linked to its multiple pharmacological effects.

Areas covered: The potential clinical benefits of albumin in select populations of critically ill patients like sepsis seem related to immunomodulatory and anti-inflammatory effects, antibiotic transportation and endothelial stabilization. Albumin transports many drugs used in critically ill patients. Such binding to albumin is frequently lessened in critically ill patients with hypoalbuminemia. These changes could result in sub-optimal treatment. Albumin has immunomodulatory capacity by binding several bacterial products. Albumin also influences vascular integrity, contributing to the maintenance of the normal capillary permeability. Moreover, the albumin molecule encompasses several antioxidant properties, thereby significantly reducing re-oxygenation injury, which is especially important in sepsis. In fact, most studies of albumin administration are a combination of a degree of resuscitation with a degree of maintenance or supplementation of albumin.

Expert commentary: The potential clinical benefits of the use of albumin in selected critically ill patients such as sepsis seem related to its immunomodulatory and anti-inflammatory effects, antioxidant properties, antibiotic transportation and endothelial stabilization. Additional studies are warranted to further elucidate the underlying physiologic and molecular rationale.  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