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   8463篇
  免费   720篇
  国内免费   445篇
耳鼻咽喉   31篇
儿科学   40篇
妇产科学   73篇
基础医学   1118篇
口腔科学   83篇
临床医学   1151篇
内科学   1572篇
皮肤病学   65篇
神经病学   459篇
特种医学   287篇
外国民族医学   15篇
外科学   915篇
综合类   932篇
现状与发展   4篇
预防医学   474篇
眼科学   79篇
药学   829篇
  39篇
中国医学   593篇
肿瘤学   869篇
  2025年   6篇
  2024年   177篇
  2023年   238篇
  2022年   494篇
  2021年   652篇
  2020年   528篇
  2019年   446篇
  2018年   418篇
  2017年   362篇
  2016年   394篇
  2015年   574篇
  2014年   658篇
  2013年   631篇
  2012年   771篇
  2011年   788篇
  2010年   506篇
  2009年   406篇
  2008年   387篇
  2007年   351篇
  2006年   308篇
  2005年   329篇
  2004年   65篇
  2003年   61篇
  2002年   25篇
  2001年   11篇
  2000年   6篇
  1999年   6篇
  1998年   5篇
  1997年   3篇
  1996年   2篇
  1995年   4篇
  1994年   4篇
  1993年   2篇
  1992年   1篇
  1990年   1篇
  1988年   1篇
  1987年   1篇
  1984年   1篇
  1983年   2篇
  1982年   2篇
  1964年   1篇
排序方式: 共有9628条查询结果,搜索用时 0 毫秒
51.
To assess the effect of Traditional Chinese Medicine (TCM) [Chinese herbal medicine ointment (CHMO), acupuncture and moxibustion] on pressure ulcer. In this study, we searched MEDLINE, EMBASE, CENTER, CBM, CNKI, WAN FANG and VIP for articles published from database inception up to 4 April 2011. We included randomised controlled trials (RCTs), which compared the effects of TCM with other interventions. We assessed the methodological quality of these trials using Cochrane risk of bias criteria. Ten of 565 potentially relevant trails that enrolled a total of 893 patients met our inclusion criteria. All the included RCTs only used CHMO intervention, because acupuncture and moxibustion trials failed to meet the inclusive criteria. A meta‐analysis showed beneficial effects of CHMO for pressure ulcer compared with other treatments on the total effective rate [risk ratio (RR): 1·28; 95% confidence interval (CI): 1·20–1·36; P = 0·53; I2 = 0%), curative ratio (RR: 2·02; 95% CI: 1·73–2·35; P = 0·11; I2 = 37%) and inefficiency rate (RR: 0·16; 95% CI: 0·02–0·80; P = 0·84; I2 = 0%). However, the funnel plot indicated that there was publication bias in this study. The evidence that CHMO is effective for pressure ulcer is encouraging, but due to several caveats, not conclusive. Therefore, more rigorous studies seem warranted.  相似文献   
52.
目的 探讨猪同种异体原位肝移植模型的改进方法。方法 选封闭群小型猪为实验动物 ,对既往猪原位肝移植模型进行系列改进 ,观察新建动物植模型的成功率、重复性和稳定性。结果在实验动物选择、手术方式及术中监护管理等方面进行改进的基础上行同种异体原位肝移植 2 0次 ,手术时间 (181.0± 2 5 .8)min及无肝期 (2 8.4± 3.2 )min较传统猪原位肝移植术明显缩短。动物术后肝功能恢复顺利 ,1周存活率 90 % ,15例动物长期存活。长期存活动物的血管和胆管并发症发生率低。结论 改进后的猪同种异体原位肝移植模型具有操作简便 ,标准化程度及手术成功率高 ,重复性和稳定性好的优点 ,是大动物肝移植系列研究的较理想动物模型  相似文献   
53.
The present study aims to define the trend of time related changes with local bacterial alteration of bacterial resistance in severe burns in our burn center during a 12-year period. Retrospective analysis of microbiological results on severely burned wounds between 1998 and 2009 was carried out. A study of 3615 microbial isolates was performed. Staphylococcus aureus was the most commonly isolated pathogen (38.2%) followed by A. baumannii (16.2%), Streptococcus viridans (11.4%), Pseudomonas aeruginosa (10.4%), coagulase-negative staphylococci (CNS, 9.2%). The species ratios of S. aureus and A. baumannii increased significantly from 1st to 8th week of hospitalization, while those of Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci decreased during the same period. Bacterial resistance rates were compared between the periods 1998-2003 and 2004-2009. Vancomycin remained as the most sensitive antibiotic in S. aureus including methicillin-resistant S. aureus (MRSA). It was very likely that the majority of infections caused by Streptococcus viridans, P. aeruginosa and coagulase-negative staphylococci occurred in the early stage of burn course and the majority of infections caused by A. baumannii occurred 4 weeks after admission. The use of different antibiotics was probably the major contributor to these trends.  相似文献   
54.
背景:关节软骨无血管分布,其营养来自关节液和软骨下骨,哪条营养通路对关节软骨更为重要是学者们争论的焦点。目的:研究软骨下营养对关节软骨的影响,并探讨软骨下营养与骨关节炎的关系。方法:45只5个月龄雄性新西兰大白兔,建立股骨滑车骨软骨缺损的动物模型,并随机分为3组:自体骨软骨块移植组(Control组,n=15);假手术组(Sham组,n=15),用环钻在股骨滑车钻取骨软骨块,将其置入管状PVC内,原位回植;阻断软骨下营养组(DNBM组,n=15),取出骨软骨后,将其置入帽状PVC内,原位回植。术后4周、8周、12周,每组5只(10膝),取出膝关节进行大体评分、组织学评分、软骨厚度测量、凋亡染色(TUNEL染色)。结果:与Control组相比,大体评分结果提示,DNBM组软骨无明显退变;组织学评分结果提示,术后12周时DNBM组软骨明显退变(P〈0.005);软骨厚度测量结果提示,术后8周、12周时DNBM组软骨厚度明显变小(P=0.00);TUNEL染色结果提示,术后8周、12周时DNBM组关节软骨细胞凋亡明显增加(P〈0.01)。结论:软骨下营养是软骨的重要营养来源,失去软骨下营养,软骨会逐渐发生退变。  相似文献   
55.
目的寻找合适PICC置管体位,以预防或减少头颈部肿瘤患者导管颈内静脉异位的发生。方法将92例需行PICC置管的头颈部肿瘤患者按置管顺序单双号分为观察组和对照组各46例,对照组取常规体位,即患者平卧,置管侧上肢外展90°,穿刺成功送管,至导管末端到达肩关节位置时,嘱患者将头偏向穿刺侧,下颌紧贴锁骨,继续送管至预测长度。观察组取改良体位,即患者平卧,头枕5cm高枕头,置管侧上肢外展45°~90°,穿刺成功送管至导管末端到达肩关节位置时,患者配合抬高穿刺侧上肢,操作者继续送管至预测长度。结果观察组导管颈内静脉异位发生率为2.17%,对照组为23.91%,两组比较,差异有统计学意义(P<0.01)。结论体位改良能有效降低头颈部肿瘤患者PICC颈内静脉异位的发生。  相似文献   
56.
ObjectivesTo study the underlying alteration in the expression of epithelial markers involved in epithelial-mesenchymal transition (EMT), and elucidate the potential mechanism(s) for Tβ4-induced EMT-like phenotypic changes in bladder cancer cells.Materials and methodsAll tissue samples in this study were obtained from clinical patients of the Union Hospital of Tongji Medical College, and were confirmed by surgery and pathology. Of these, normal bladder tissues (control), primary urothelial carcinoma of different grades (Stage pTa, Stage pT3), bladder paracancerous tissues, accompanied with 2 bladder cancer cell lines (BIU-87 and T24), were divided into 6 groups. Quantitative RT-PCR, Western blotting, and immunohistochemical study of adhesion molecules Tβ4, ILK, E-cadherin, and β-catenin involved in EMT were carried out. A lentiviral gene transferring vector containing the RNA polymerase III-dependent U6 promoter to express short hairpin RNA (shRNA) directed against Tβ4 was also applied. In the present study, all agents were evaluated using commercial kits.ResultsA strong correlation between the expression levels of Tβ4, ILK, E-cadherin, and β-catenin was found in the bladder transitional cell carcinoma (TCC) patients. In the BIU-87 and T24 bladder cancer cells overexpressing Tβ4, which were accompanied by a loss of E-cadherin as well as a cytosolic accumulation of β-catenin, up-regulation of ILK was also revealed. The inhibition of the Tβ4 expression with lentiviral shRNA vector could raise EMT-like phenotypic changes, significantly depressed motility, and subsequent invasiveness of bladder cancer cells.ConclusionsOur results imply that the Tβ4 is likely to play a crucial role in EMT progression, and that inhibition of the Tβ4 expression or interactions with other genes should be novel therapeutic targets for bladder cancers with high invasive and metastatic potential.  相似文献   
57.

Purpose

Implant-related infections are disastrous complications in the clinic, and there are no effective therapies. In this preliminary study, gentamicin-loaded coating on titanium implants was prepared using the electrospinning technique, and some properties of the coating titanium implants were studied.

Methods

We adopted the electrospinning technique to prepare gentamicin-coated titanium implants. The surface structure of the coating implants was observed using scanning electron microscope. An elution study was performed to determine the release behavior of the gentamicin from the coating. The antibacterial efficacy and quantitative analysis of the bacterial adhesion of Staphylococcus aureus were evaluated in vitro, and the cytotoxicity of the coated titanium implants on osteoblasts was investigated in vitro.

Results

The morphology of the gentamicin-coated titanium implants exhibited nanofibers, and the release of gentamicin showed an initial gentamicin burst followed by a slow release. The gentamicin-coated titanium implants had a persistent antibacterial efficacy for 1 week and significantly reduced the adhesion of the Staphylococcus aureus compared with bare titanium implants in vitro. There was no cytotoxicity observed in vitro for the gentamicin-coated implants.

Conclusion

The gentamicin-coated titanium implants, which were prepared using an electrospinning technique, present many advantages and may be considered to prevent and treat the implant-related infections.  相似文献   
58.
对1例肺、肾功能衰竭患者行组合式体外膜肺联合连续性血液净化治疗,结果患者病情得到控制并最终康复出院.提出多器官功能衰竭患者病情发展迅速,预后极差,在临床上除行体外膜肺联合连续性血液净化治疗的护理外,还应注意预防感染、出血等严重并发症,以积极改善预后,提高患者生活质量.  相似文献   
59.

Background

In recent years, submucosal tunneling endoscopic resection (STER) has emerged as a novel therapeutic endoscopic technique for upper gastrointestinal submucosal tumors (SMTs). The aim of this study was to evaluate the safety and efficacy of STER for upper gastrointestinal SMTs.

Methods

A systematic search of both English and Chinese databases was performed until November 15, 2015. Complete resection and en bloc resection rates were considered the primary outcome measures. Prevalence of complications was considered the secondary outcome measure. A random-effects model was used to generate conservative estimates of the prevalence of the main outcome variables. All data analyses were performed using Meta-Analyst software (version beta 3.13).

Results

A total of 28 studies were included in the final meta-analysis. The pooled complete resection and en bloc resection rates were 97.5 % (95 % CI 96.0–98.5 %) and 94.6 % (95 % CI 91.5–96.7 %), respectively. The common complications associated with STER were air leakage symptoms and perforation. The pooled prevalence of air leakage symptoms was 14.8 % (95 % CI 10.5–20.5 %) for subcutaneous emphysema and pneumomediastinum, 6.1 % (95 % CI 4.0–9.0 %) for pneumothorax and 6.8 % (95 % CI 4.7–9.6 %) for pneumoperitoneum. Additionally, the pooled prevalence of perforation was 5.6 % (95 % CI 3.7–8.2 %). Only a few cases of bleeding were reported in two studies.

Conclusions

STER is a highly feasible and safe treatment option for upper gastrointestinal SMTs.
  相似文献   
60.
阐述影响脑卒中患者跌倒恐惧的因素,包括人口学因素、跌倒史、平衡功能、功能锻炼情况及焦虑、抑郁情绪等。提出医护人员可通过评估工具对患者跌倒恐惧情况进行测量,根据患者的个体情况,制定相应的干预措施,帮助患者降低跌倒恐惧,提升其日常生活功能的独立性,增强其对自身跌倒预防的信心,从而有效预防脑卒中患者跌倒的发生。  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