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   542篇
  免费   22篇
  国内免费   2篇
耳鼻咽喉   4篇
儿科学   11篇
妇产科学   6篇
基础医学   41篇
口腔科学   39篇
临床医学   51篇
内科学   61篇
神经病学   19篇
特种医学   70篇
外科学   116篇
综合类   1篇
预防医学   88篇
眼科学   2篇
药学   36篇
肿瘤学   21篇
  2024年   1篇
  2023年   4篇
  2022年   7篇
  2021年   15篇
  2020年   7篇
  2019年   12篇
  2018年   22篇
  2017年   12篇
  2016年   15篇
  2015年   15篇
  2014年   28篇
  2013年   41篇
  2012年   52篇
  2011年   53篇
  2010年   45篇
  2009年   30篇
  2008年   24篇
  2007年   30篇
  2006年   32篇
  2005年   21篇
  2004年   16篇
  2003年   24篇
  2002年   25篇
  2001年   6篇
  2000年   6篇
  1999年   3篇
  1998年   3篇
  1997年   3篇
  1996年   2篇
  1995年   3篇
  1994年   2篇
  1989年   1篇
  1988年   1篇
  1987年   1篇
  1984年   1篇
  1981年   1篇
  1976年   2篇
排序方式: 共有566条查询结果,搜索用时 31 毫秒
1.
We prospectively enrolled 160 consecutive patients with inversion trauma of the ankle in a diagnostic protocol that included physical examination within 2 days and at 5 days after trauma, arthrography, stress radiography, and ultrasonography. 135 patients had pathological lateral ligament laxity on the later physical examination or lateral ligament rupture diagnosed on arthrography and they were operated on. 122 of these patients had ligament ruptures.

At clinical follow-up after a minimum of half a year, all of the patients who were not operated on had stable joints without signs of previous ligament ruptures.

Delayed physical examination at 5 days after the injury led to the highest overall sensitivity (96%) and specificity (84%) for the detection of a ligament rupture. Additional diagnostic procedures, at a considerable cost, yielded little additional information.  相似文献   
2.

Background  

Given the proliferation and the growing complexity of performance measurement initiatives in many health systems, the Netherlands and Ontario, Canada expressed interests in cross-national comparisons in an effort to promote knowledge transfer and best practise. To support this cross-national learning, a study was undertaken to compare health system performance approaches in The Netherlands with Ontario, Canada.  相似文献   
3.
Questions addressed in this in-vitro study are (1) what are the actual three-dimensional kinematics of talus and calcaneus during an anterior drawer test as performed with the quasi-static anterior ankle tester (QAAT) (2) does laxity measurement with the QAAT represent the true anterior translation of talus relative to the tibia?. Simultaneous measurements were made with the QAAT and a three-dimensional kinematics analysis system in five specimens. The three-dimensional translations and rotations on three axes were analysed at 25, 50 and 100 N of applied anterior load, with increased ligament damage. For four out of five remaining specimens, anterior translation values of talus and calcaneus and values as measured with the QAAT show a significant increase with growing ligament damage and with higher loads. Skeletal motions of talus and calcaneus show great similarity in three different motion axes, with increased ligament damage and at any given load. Skeletal translations and rotations of talus and calcaneus show great similarity during an anterior drawer movement of the ankle joint. Anterior skeletal translation of the talus and calcaneus show fair correlation with the anterior displacements measurements of the QAAT. These QAAT measurements show an overestimation of the laxity value by more than 200% irrespective of the load applied.  相似文献   
4.
The prognostic impact of mucinous carcinoma (MC) in colorectal cancer (CRC) has been subject to debate ever since the introduction of the classification of tumors according to their histological differentiation. MC is a distinct clinical and pathological entity within the spectrum of CRC and accounts for approximately 10–15 % of cases. Factors involved in MC development have not been completely understood, but clinical observations may lead to a better insight into the etiology of MC. In this article, we provide an in-depth review of the literature regarding etiological aspects of MC. We show that there are worldwide differences in the prevalence of MC, with low rates in Asian countries and higher rates in the western world. Moreover, MC is more commonly diagnosed in patients suffering from inflammatory bowel diseases or Lynch syndrome and an increased rate of MC is observed in patients with radiotherapy-induced CRCs. These findings are suggestive of a different oncogenic development. Identification of conditions that are associated with MC generates insight into the etiological pathways leading to the development of this special subtype.  相似文献   
5.
ObjectivesOur study investigates the extent to which uptake of a COVID-19 digital contact-tracing (DCT) app among the Dutch population is affected by its configurations, its societal effects, and government policies toward such an app.MethodsWe performed a discrete choice experiment among Dutch adults including 7 attributes, that is, who gets a notification, waiting time for testing, possibility for shops to refuse customers who have not installed the app, stopping condition for contact tracing, number of people unjustifiably quarantined, number of deaths prevented, and number of households with financial problems prevented. The data were analyzed by means of panel mixed logit models.ResultsThe prevention of deaths and financial problems of households had a very strong influence on the uptake of the app. Predicted app uptake rates ranged from 24% to 78% for the worst and best possible app for these societal effects. We found a strong positive relationship between people’s trust in government and people’s propensity to install the DCT app.ConclusionsThe uptake levels we find are much more volatile than the uptake levels predicted in comparable studies that did not include societal effects in their discrete choice experiments. Our finding that the societal effects are a major factor in the uptake of the DCT app results in a chicken-or-the-egg causality dilemma. That is, the societal effects of the app are severely influenced by the uptake of the app, but the uptake of the app is severely influenced by its societal effects.  相似文献   
6.
7.
In recent years much research in RNA nanotechnology has been directed to develop an efficient and clinically suitable delivery system for short interfering RNA (siRNA). The current study describes the in vivo siRNA delivery using PEGylated antibody-targeted SAINT-based-lipoplexes (referred to as antibody-SAINTPEGarg/PEG2%), which showed superior siRNA delivery capacity and effective down-regulation of VE-cadherin gene expression in vitro in inflammation-activated primary endothelial cells of different vascular origins. PEGylation of antibody-SAINTPEGarg resulted in more desirable pharmacokinetic behavior than that of non-PEGylated antibody-SAINTPEGarg. To create specificity for inflammation-activated endothelial cells, antibodies against vascular cell adhesion molecule-1 (VCAM-1) were employed. In TNFα-challenged mice, these intravenously administered anti-VCAM-1-SAINTPEGarg/PEG2% homed to VCAM-1 protein expressing vasculature. Confocal laser scanning microscopy revealed that anti-VCAM-1-SAINTPEGarg/PEG2% co-localized with endothelial cells in lung postcapillary venules. Furthermore, they did not exert any liver and kidney toxicity. Yet, lack of in vivo gene silencing as assessed in whole lung and in laser microdissected lung microvascular segments indicates that in vivo internalization and/or intracellular trafficking of the delivery system and its cargo in the target cells are not sufficient, and needs further attention, emphasizing the essence of evaluating siRNA delivery systems in an appropriate in vivo animal model at an early stage in their development.  相似文献   
8.
Short-term treatment of gastroesophageal reflux disease   总被引:2,自引:0,他引:2       下载免费PDF全文
OBJECTIVE: To investigate the efficacy of acid suppressant drugs in the empirical treatment of gastroesophageal reflux disease (GERD) and in the treatment of endoscopy-negative reflux disease (ENRD). DESIGN: medline, embase, and the Cochrane Controlled Trials Register were searched. Bibliographies were reviewed. SETTING: Studies were eligible that compared the short-term use of proton pump inhibitors (PPIs) and histamine-2 receptor antagonists (H2RAs) with each other or with placebo in adults with GERD who were enrolled irrespective of endoscopic findings (empirical cases) or in whom endoscopy showed no signs of esophagitis (endoscopy-negative cases). MEASUREMENTS: Of 1,408 studies, only 13 could be included for meta-analysis. Data on 3,433 patients empirically treated for GERD and 2,520 patients treated for ENRD were extracted. The primary endpoint was relief of heartburn. MAIN RESULTS: In the empirical treatment of GERD, the summary relative risk (sRR) for symptom relief from H2RAs versus placebo was 0.77 (95% confidence interval [95% CI], 0.60 to 0.99). RR in the only placebo-controlled PPI trial was 0.35 (95% CI, 0.26 to 0.46). The sRR for standard dose PPIs versus H2RAs was 0.55 (95% CI, 0.44 to 0.68). In treatment of ENRD, both PPIs (sRR, 0.64; 95% CI, 0.52 to 0.79) and H2RAs (sRR, 0.78; 95% CI, 0.62 to 0.97) were superior to placebo, and PPIs were superior to H2RAs (sRR, 0.81; 95% CI, 0.70 to 0.95). CONCLUSIONS: Acid suppressant therapy (with a PPI or an H2RA) is more effective than placebo for short-term relief of heartburn in patients with persistent symptoms who are treated empirically for GERD and in those in whom esophagitis was excluded after endoscopy. The benefit of PPIs compared with H2RAs is more pronounced in patients treated empirically.  相似文献   
9.
BACKGROUND: Acute exacerbations of asthma and chronic obstructive pulmonary disease (COPD) are associated with increased airflow Limitation, hyperinflation and respiratory muscle fatigue. It is unclear, whether patients are able to perform adequate inhalations through various inhalation devices with different orfices during an exacerbation. The aim of this study was to examine the evolution of inhalation profiles of patients inhaling through Diskus, Turbuhaler, pressurized metered dose inhaler (pMDI) and Volumatic and consequently the appropriateness of using the various devices during an exacerbation. MEASUREMENTS: 15 hospitalized patients participated in this randomized comparison of inhalation profiles through the four placebo-devices. For each device, triplicate inhalation profiles were recorded during day 1-9 of admission and in stable phase (day 50). RESULTS: The mean percentage of patients performing optimum inhalation profiles was 100% for Diskus, 60% for Turbuhaler, 14% for pMDI and 87% for Volumatic over the interval of day 1-9 and day 50. Patients with an inspiratory muscle strength (MIP) of less than 6kPa were generally unable to generate the optimum flow through the Turbuhaler (>60 l/min). CONCLUSION: The Diskus and Volumatic can be used effectively in the acute phase of an exacerbation of asthma or COPD. The Turbuhaler could be optimally used after the fifth day of convalescence. The pMDI is rather unsuitable during an exacerbation.  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