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   417篇
  免费   47篇
  国内免费   2篇
耳鼻咽喉   7篇
儿科学   11篇
妇产科学   2篇
基础医学   28篇
口腔科学   5篇
临床医学   68篇
内科学   37篇
皮肤病学   1篇
神经病学   8篇
特种医学   5篇
外科学   11篇
综合类   83篇
预防医学   106篇
眼科学   2篇
药学   37篇
中国医学   43篇
肿瘤学   12篇
  2023年   6篇
  2022年   21篇
  2021年   20篇
  2020年   23篇
  2019年   16篇
  2018年   19篇
  2017年   14篇
  2016年   12篇
  2015年   12篇
  2014年   34篇
  2013年   20篇
  2012年   37篇
  2011年   38篇
  2010年   29篇
  2009年   23篇
  2008年   29篇
  2007年   16篇
  2006年   23篇
  2005年   19篇
  2004年   7篇
  2003年   8篇
  2002年   2篇
  2001年   6篇
  2000年   5篇
  1999年   6篇
  1998年   2篇
  1997年   3篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1990年   1篇
  1989年   1篇
  1985年   2篇
  1983年   1篇
  1982年   1篇
  1980年   1篇
  1979年   2篇
  1975年   1篇
排序方式: 共有466条查询结果,搜索用时 15 毫秒
1.
在概述了灰色文献的起源、内涵、外延及其他特征的基础上,对各国学者对灰色文献的研究进行了比较分析,对灰色文献的自身价值和社会作用进行了分析评价.  相似文献   
2.
BackgroundEndoscopy plays a pivotal role in the management of adverse events (AE) following bariatric surgery. Leaks, fistulae, and post-operative collection after sleeve gastrectomy (SG) may occur in up to 10% of cases.ObjectivesTo evaluate the efficacy and safety of endoscopic internal drainage (EID) for the management of leak, fistula, and collection following SG.SettingRetrospective, observational, single center study on patients referred from several bariatric surgery departments to an endoscopic referral center.MethodsEID was used as first-line treatment for the management of leaks, fistulae, and collections. Leaks and fistulae were treated with double pigtail stent (DPS) deployment in order to guarantee internal drainage and second intention cavity obliteration. Collections were treated with endoscropic ultrasound (EUS)–guided deployment of DPS or lumen apposing metal stents.ResultsA total of 617 patients (83.3% female; mean age, 43.1 yr) were enrolled in the study for leak (n = 300, 48.6%), fistula (n = 285, 46.2%), and collection (n = 32, 5.2%). Median follow-up was 19.5 months. Overall clinical success was 84.7% whereas 15.3% of cases required revisional surgery after EID failure. Clinical success according to type of AE was 89.5%, 78.5%, and 90% for leak, fistula, and collection, respectively. A total of 10 of 547 (1.8%) presented a recurrence during follow-up. A total of 28 (4.5%) AE related to the endoscopic treatment occurred. At univariate logistic regression predictors of failure were: fistula (OR 2.012), combined endoscopic approach (OR 2.319), need for emergency surgery (OR 1.755), and previous endoscopic treatment (OR 4.818).ConclusionEarly EID for the management of leak, fistula, and post-operative collection after SG seems a safe and effective first-line approach with good long-term results.  相似文献   
3.
网络环境下提高外文期刊文献保障能力的实践与体会   总被引:3,自引:0,他引:3  
以广州中医药大学图书馆为例,分析总结了网络环境下提高外文期刊文献保障能力的经验:购买引进电子期刊、开发网络免费电子期刊资源、通过馆际互借与文献传递、建立高校协作组、开展国际期刊交流等。  相似文献   
4.
Purpose:This study aims to facilitate researchers’ and clinicians’ understanding of research frontiers and trends in nocturia. It explores the scientific research outcomes and key bibliometric indices and plots global research on nocturia.Methods:A bibliometric retrospective study was designed, and an online search was conducted in the Web of Science Core Collection database using the potential search keywords related to nocturia in the title field with some specific filtration. HistCite™ and VOSviewer software for windows were used to analyze the data obtained for authors, journals, countries, institutions, keywords, and visualization mapping.Results:The initial search retrieved 1479 hits. A total of 1445 publications were included in the final analysis. Of these, 43.53% were published as articles. The most studied area in nocturia is urology nephrology. The most productive year was 2019 (n = 121, citations = 335), and the most prolific author, both in terms of publications (n = 97) and citations (1658) was Weiss JP. The most cited journal in nocturia research was the Journal of Urology (n = 293, citations = 3050). The most widely used keyword in nocturia publications was nocturia (n = 1249). Visualization mapping shows that the USA was the most influential and highly cited country in nocturia research.Conclusion:This study showed that there has been an increasing research trend in nocturia over the past few years. The current findings provide important empirical evidence for researchers, clinicians, and physicians to understand research frontiers and trends, achievements, collaborative networks, and hotspot research topics in the research field of nocturia.  相似文献   
5.
目的:研究影响骨髓造血干细胞动员及采集的因素。方法方便选取2013年3月_2016年6月期间就诊该院的77名健康供者,经重组人粒细胞集落刺激因子(rhG-CSF﹚动员后第4天采集骨髓,分析不同健康供者的年龄和性别对骨髓造血干细胞采集的影响以及采集时外周血白细胞数与采集效果的关系。结果77名供者均成功采集,骨髓采集物单个核细胞数(BM-MNCs)为(4.3±0.43﹚×108/kg,骨髓采集物CD34+细胞数(BM-CD34+﹚为(1.84±0.30﹚×106/kg,健康供者年龄和性别差异无统计学意义,采集时外周血白细胞数不能预测骨髓采集物中CD34+细胞的数量。结论采用5~10μg/kg G-CSF动员,健康供者均可成功采集骨髓干细胞。  相似文献   
6.
国内菌种保藏材料及保藏方法研究现状   总被引:1,自引:0,他引:1  
为更好开展我国生物资源保藏保护,作者检索了国内十一五以来的相关文献,综述了我国菌种保藏材料及保藏技术、方法等方面的进展.目前,国内菌种保藏材料上仍多采用明胶片、滤纸片、乳类、糖类、液体中药等;保藏技术和方法上仍以低温或超低温冷冻冷藏等为主.提示国内在菌种保藏材料及保藏方法方面有一定进展.  相似文献   
7.
ObjectiveBlood culture contamination above the national threshold has been a consistent clinical issue in the ED setting. Two commercially available devices were examined that divert an initial small volume of the specimen before the collection of blood culture to reduce skin contamination.MethodsProspectively, 2 different blood culture–diversion devices were made available in the unit supplies to ED clinicians at a single site during 2 different periods of time as a follow-up strategy to an ongoing quality improvement project. Blood samples were collected in the emergency department over a period of 16 months. A retrospective record review study was conducted comparing the use of the 2 specimen-diversion devices with no device (control group) for blood culture contamination rates. The main outcome of monthly blood culture contamination per device was tested using a Bayesian Poisson multilevel regression model.ResultsA total of 4030 blood samples were collected and analyzed from November 2017 to February 2019. The model estimated that the mean incidence of contaminated blood draws in the device A group was 0.29 (0.14-0.55) times the incidence of contaminated draws in the control group. The mean incidence of contaminated blood draws in the device B group was 0.23 (0.13-0.37) times the incidence of contaminated draws in the control group, suggesting that initial-diversion methods reduced blood culture contamination.ConclusionInitial specimen–diversion devices supplement present standard phlebotomy protocols to bring down the blood culture contamination rate.  相似文献   
8.
目的:分析比较外周静脉留置针穿刺采血与直接静脉穿刺采血血培养标本污染发生率。方法对儿科病房2012年4月~2013年9月送检的血培养标本结果进行回顾性调查,比较两种不同方法采集血培养标本发生的污染率。结果3016份送检的血培养标本中,判断为污染菌的有67例,总污染率为2.2%。外周静脉留置针穿刺采血594例,判断为污染12例,污染率为2.0%;直接静脉穿刺采血2422例,判断为污染54例,污染率2.2%。结论外周静脉留置针穿刺采血与直接静脉穿刺采血,血培养标本污染的发生率差异无显著意义。儿科血培养的采集可以在新置入的外周静脉留置针内采血。  相似文献   
9.
Plasma rich platelets (PRP) consist of blood plasma with a high concentration of platelets autologous constituting a huge reservoir of growth factors. The clinical use of the PRP is widespread in various medical applications. Even it is very popular with athletes, the use of PRP in tendinopathies is still scientifically discussed, particularly related to a disparity in the products called PRP. In order to optimize employment, it should be interested in the different stages of obtaining of the PRP. In this literature review, we analyzed in particular 8 parameters that can influence the quality of the PRP: (1) anticoagulants used to preserve the best feature of platelet; (2) centrifuge speeds used in order to extract platelets; (3) platelet concentrations and the presence of leukocytes and erythrocytes in the PRP; (4) the platelet activators for the mast of platelets and thus the release of growth factors; (5) use of local anesthetics to achieve infiltration, in addition to these parameters, it might be interesting to analyze other variables like: (6) employment or not of buffer to neutralize the acidity caused by anticoagulants; (7) injection under US guidance or not; and (8) volume of PRP injected to determine their influence on the healing potential.  相似文献   
10.
This study sought to prepare a self-microemulsion drug delivery system containing zingerone (Z-SMEDDS) to improve the low oral bioavailability of zingerone and anti-tumor effect. Z-SMEDDS was characterized by particle size, zeta potential and encapsulation efficiency, while its pharmacokinetics and anti-tumor effects were also evaluated. Z-SMEDDS had stable physicochemical properties, including average particle size of 17.29 ± 0.07 nm, the zeta potential of -22.81 ± 0.29 mV, and the encapsulation efficiency of 97.96% ± 0.02%. In vitro release studies have shown the release of zingerone released by Z-SMEDDS was significantly higher than free zingerone in different release media. The relative oral bioavailability of Z-SMEDDS was 7.63 times compared with free drug. Meanwhile, the half inhibitory concentration (IC50)of Z-SMEDDS and free zingerone was 8.45 μg/mL and 13.30 μg/mL, respectively on HepG2. This study may provide a preliminary basis for further clinical research and application of Z-SMEDDS.  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