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   12261篇
  免费   950篇
  国内免费   531篇
耳鼻咽喉   119篇
儿科学   215篇
妇产科学   204篇
基础医学   1383篇
口腔科学   349篇
临床医学   1044篇
内科学   1254篇
皮肤病学   141篇
神经病学   651篇
特种医学   824篇
外国民族医学   19篇
外科学   1237篇
综合类   2155篇
现状与发展   2篇
预防医学   575篇
眼科学   165篇
药学   1026篇
  5篇
中国医学   406篇
肿瘤学   1968篇
  2024年   12篇
  2023年   116篇
  2022年   187篇
  2021年   302篇
  2020年   320篇
  2019年   290篇
  2018年   301篇
  2017年   333篇
  2016年   343篇
  2015年   336篇
  2014年   623篇
  2013年   687篇
  2012年   669篇
  2011年   834篇
  2010年   702篇
  2009年   642篇
  2008年   690篇
  2007年   693篇
  2006年   662篇
  2005年   587篇
  2004年   475篇
  2003年   448篇
  2002年   423篇
  2001年   355篇
  2000年   306篇
  1999年   251篇
  1998年   232篇
  1997年   214篇
  1996年   200篇
  1995年   154篇
  1994年   173篇
  1993年   126篇
  1992年   110篇
  1991年   108篇
  1990年   90篇
  1989年   85篇
  1988年   98篇
  1987年   79篇
  1986年   69篇
  1985年   107篇
  1984年   53篇
  1983年   41篇
  1982年   47篇
  1981年   53篇
  1980年   44篇
  1979年   33篇
  1978年   12篇
  1977年   9篇
  1976年   9篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
《Cancer cell》2022,40(8):835-849.e8
  1. Download : Download high-res image (220KB)
  2. Download : Download full-size image
  相似文献   
2.
3.
4.
PurposeIn 2018, The Journal of Vascular and Interventional Radiology (JVIR) updated its guidelines regarding periprocedural antibiotics. However, some institutions are slower to adopt these new guidelines. Additionally, antibiotic-resistant bacteria and sepsis are serious concerns due in part to incorrect usage of antibiotics. The purpose of this study is to assess institutional adherence to 2018 JVIR guidelines for the purpose of improving antibiotic stewardship.Materials and methodsA total of 800 cases over a 10-month time period were retrospectively identified and charted following the release of guidelines. Inclusion criteria for the study were adults aged 21 years or older undergoing mediport placement, tunneled central line (TCL) placement, nephrostomy tube exchange, percutaneous biliary drain, or cholecystostomy tube exchange. Exclusion criteria included immunocompromised and pregnant individuals as 2018 guidelines may not fit these patient populations. Guideline adherence for each procedure was recorded as a percentage; the timing of the antibiotic usage was also recorded and compared to the guidelines (within 60 minutes before incision).ResultsIn total, 49 mediport placements, 118 tunneled central line placements – 44 hemodialysis (HD) catheters and 74 nonhemodialysis (non-HD) catheters, 100 nephrostomy exchanges, and 82 biliary tube exchanges were included. Antibiotics were used in 83.6% (41/49) of mediport patients, 11.3% (5/44) of non-HD TCL patients, 20.5% (15/74) of HD TCL patients, 55% (55/100) nephrostomy tube changes, and 65.4% (55/84) of biliary or cholecystostomy tube exchanges. Out of those given prophylaxis, guideline-recommended antibiotics were used in 100% (41/41) of mediport, 100% (20/20) of TCL (both HD and non-HD catheters), 9% (5/55) of nephrostomy tube exchanges, and 1.8% (1/55) of biliary tube exchanges. Guideline-recommended timing was followed in 75.3% across all cases (ranging from 72.2% in mediports to 79.3% in biliary exchanges).ConclusionThis study of antibiotic practices at a single university-based academic institution revealed that antibiotic usage is not fully up to date with 2018 guidelines. For mediports, non-HD TCL placements, and nephrostomy tube exchanges, institutional changes should be made to reduce periprocedural antibiotic use, as antibiotics are no longer recommended for these procedures. For HD TCL and biliary exchanges, proper adherence to recommended prophylactic antibiotics should be followed. In addition, education about the correct antibiotic timing should be emphasized to increase compliance with guidelines.  相似文献   
5.
6.
全膝关节置换术是目前治疗终末期膝关节骨性关节炎最有效的方法之一,全膝关节置换术后膝关节功能、术后膝关节疼痛与术后下肢力线有着密切的关系。目前膝关节置换术下肢对线方式主要采用机械力学对线方法,该方法可以改善膝关节功能,但是有部分患者也会产生术后膝关节的疼痛、活动受限等并发症,导致术后患者满意度较差。近些年越来越多的研究开始关注运动力学对线技术并应用于临床。运动学对线技术旨在重建患者的解剖结构,将膝关节假体运动轴与膝关节生理性运动轴保持一致,减少膝关节周围软组织和韧带的松解,实现膝关节生理性运动。该文就运动力学对线方法在全膝关节置换术中的应用进展作一综述。  相似文献   
7.
ObjectiveThe detection of abnormal findings on computed tomography (CT) scans of tuberculosis contacts combined with normal plain radiographs contributes to the early detection of tuberculosis. However, the benefit of the early detection of abnormalities for the prevention of active tuberculosis during follow-up requires evaluation.MethodWe conducted retrospective comparison of the existence of CT scans of tuberculosis contacts without findings of active tuberculosis on plain radiographs at a hospital in Japan. Results: Among 243 contacts without CT scans, five developed tuberculosis during follow-up. Among 229 contacts with CT scans, 24 were judged as targets of multi-drug therapy since their CT findings were suggestive of active tuberculosis at the time of the CT screening. Among 205 contacts judged as having latent tuberculous infection with CT screening, three developed tuberculosis diseases during follow-up. Conclusion: CT scans detected abnormal findings among contacts without abnormalities of plain radiographs but there were some contacts that developed tuberculosis diseases among those with contact investigation including CT scan. The value of CT is equivocal considering the balance of true treatment, overtreatment and harm of radiation.  相似文献   
8.
摘要〓目的〓研究四腔水箱在腹外科腔镜电凝线擦拭法清洗消毒中的应用效果。方法〓通过目测法和ATP生物荧光法,对本研究的四腔水箱用于腹外科腔镜电凝线的清洗效果进行评价。结果〓传统治疗碗清洗的206件腔镜电凝线清洗质量合格率为86.4%,四腔水箱清洗的206件腹腔镜电凝线清洗质量合格率为94.6%,差异有统计学意义(P<0.01)。用四腔水箱清洗腔镜电凝线擦拭过程中的护理人员满意度较高。结论〓四腔水箱可提高腹外科腔镜电凝线清洗质量和护理人员满意度。  相似文献   
9.
Using JEG-3 and BeWo cells, we examined the effect of “real life” mixtures of polycyclic aromatic hydrocarbons (PAHs), at doses reported in maternal blood (Mix I) and in placental tissue (Mix II), on human chorionic gonadotropin (hCG), placental lactogen (hPL) and placental growth factor (hPLGF) secretion, protein expression and immunolocalization. Additionally, the action of PAH mixtures on basal and hormone-stimulated matrix metalloproteinase-2 (MMP-2), MMP-9 and vascular endothelial growth factor (VEGF) protein expression was evaluated. Under basal conditions, the PAH mixtures increased hCG and decreased hPLGF levels in both cell lines, while hPL expression was stimulated in JEG-3 and inhibited in BeWo. There was no effect on the MMP-2/MMP-9 ratio or VEGF expression. In hormone-stimulated cells, PAH mixtures changed the MMP-2/MMP-9 ratio in JEG-3 cells in favor of MMP-9, while in BeWo MMP-2 was favored. The effect on VEGF expression was cell specific and dependent on the mixture. In hCG-treated cells, only Mix II inhibited VEGF expression in JEG-3 cells. Neither PAH mixtures affected this protein in BeWo cells. In hPL-treated cells, Mix I had a stimulatory effect in JEG-3 cells, while Mix II exerted an inhibitory effect in BeWo cells. In hPLGF-treated cells, Mix II decreased in JEG-3 cells, but in BeWo cells, both mixtures increased VEGF expression. Considering that the evaluated protein hormones play crucial roles in angiogenesis and neovascularization in the placenta, “real life” PAH mixtures by disrupting protein hormones levels, the MMP-2/MMP-9 ratio and VEGF expression can lead to insufficiency and many pregnancy-related disorders.  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