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   3572篇
  免费   333篇
  国内免费   7篇
耳鼻咽喉   35篇
儿科学   91篇
妇产科学   121篇
基础医学   569篇
口腔科学   110篇
临床医学   346篇
内科学   661篇
皮肤病学   73篇
神经病学   305篇
特种医学   283篇
外科学   595篇
综合类   106篇
一般理论   3篇
预防医学   209篇
眼科学   101篇
药学   161篇
中国医学   24篇
肿瘤学   119篇
  2021年   35篇
  2018年   47篇
  2017年   38篇
  2016年   34篇
  2015年   48篇
  2014年   72篇
  2013年   99篇
  2012年   124篇
  2011年   122篇
  2010年   88篇
  2009年   75篇
  2008年   116篇
  2007年   140篇
  2006年   130篇
  2005年   114篇
  2004年   117篇
  2003年   101篇
  2002年   104篇
  2001年   101篇
  2000年   103篇
  1999年   91篇
  1998年   75篇
  1997年   63篇
  1996年   58篇
  1995年   48篇
  1994年   47篇
  1993年   38篇
  1992年   68篇
  1991年   68篇
  1990年   81篇
  1989年   93篇
  1988年   93篇
  1987年   81篇
  1986年   67篇
  1985年   83篇
  1984年   53篇
  1983年   43篇
  1982年   43篇
  1981年   40篇
  1980年   35篇
  1979年   46篇
  1978年   35篇
  1977年   49篇
  1976年   31篇
  1975年   39篇
  1974年   45篇
  1973年   38篇
  1972年   40篇
  1970年   44篇
  1968年   43篇
排序方式: 共有3912条查询结果,搜索用时 15 毫秒
131.
目的比较不同预防性用药方案在新置腹膜透析导管患者的使用情况,探讨抗生素用药在预防新置腹膜透析导管患者术后发生腹膜炎的重要性。方法回顾性分析2008年10月至2012年10月在北京大学深圳医院肾内科腹膜透析中心接受腹膜透析置管术开始行腹膜透析治疗的患者173例。按照预防性使用抗生素方法分为3组,A组:患者在腹膜透析置管术后3天内使用含有头孢唑啉0.25g/L的腹透液,共计101例次;B组:患者在腹膜透析置管术前3h静脉滴注头孢唑林0.5g,共计48例次;C组:患者术前及术后3天均未使用抗生素,共计24例次。比较3组患者术后14天内腹膜炎的发生率。结果 A组101例患者中1例出现腹膜炎,发生在术后第11天,占0.99%;B组48例患者中2例出现腹膜炎,均发生在术后第1天,占4.17%;C组24例患者中4例出现腹膜炎,3例发生在术后第1天,1例发生在术后第2天,占16.67%。对3组患者腹膜炎发生率进行两两比较,A组与C组比较,P=0.005,P<0.01,差异有统计学意义;B组与C组比较,P>0.05,差异无统计学意义;A组与B组比较,P>0.05,差异无统计学意义。结论腹膜透析置管术围手术期预防性抗生素用药十分有必要,术后腹腔内给药或术前一次静脉用药能有效预防术后腹膜炎发生。  相似文献   
132.
BAROREFLEX MECHANISMS IN HYPERTENSION   总被引:2,自引:0,他引:2  
  相似文献   
133.
134.
目的 评价改良小梁切除术治疗伴有高眼压及大瞳孔的急性房角关闭的临床疗效。方法收集2005年1月至2009年3月中山大学中山眼科中心青光眼专业实施改良小梁切除术治疗伴有高眼压及大瞳孔的急性房角关闭21例(21眼)的临床资料,对术后并发症及手术前后的眼压、视力、瞳孔等进行统计分析。 结果 术前眼压(48.25±3.14) mmHg,平均用降眼压药种类3.35种,明显高于出院时眼压(10.47±1.15)mmHg(t=11.4573,P<0.01)及术后3个月眼压(13.86±0.93) mmHg(t=11.2641,P<0.01)。出院视力(0.09±0.05)与术前视力(0.11±0.06)差异无统计学意义(沁0.8702,P= 0.3913),术后3个月视力(0.21±0.04)则稍好于术前(t=-2.7907,P=0.0112)。术前瞳孔垂直径(5.81±0.23) mm与出院时瞳孔垂直径(5.92±0.21 )mm差异无统计学意义(t=-1.5013,P=0.1672)。无严重并发症发生。 结论 改良小梁切除术是治疗伴有高眼压及大瞳孔的急性房角关闭的有效方法,术中分次放房水、巩膜瓣调节缝线、术毕形成前房等措施可有效减少严重并发症的发生。  相似文献   
135.
BACKGROUND: Hepatocyte growth factor (HGF) is a pleiotropic protein with renoprotective functions, which have been attributed at least in part to its ability to counteract the profibrotic effects of transforming growth factor beta (TGF-beta). A major downstream mediator of TGF-beta is connective tissue growth factor (CTGF). However, the molecular mechanisms of CTGF regulation by HGF have not yet been investigated. METHODS: CTGF expression was analysed in human primary tubular epithelial cells (hPTECs) and the cell line HKC-8 by western blotting. Morphological alterations were analysed by immunocytochemistry. RESULTS: HGF induced a transient expression of CTGF, which was maximal after 6 h and returned to baseline after 24 h. Coincubation with TGF-beta increased CTGF protein at 6 h, whereas HGF significantly decreased CTGF induction by TGF-beta after 24 h. Furthermore, HGF induced cell scattering associated with reorganization of focal adhesions and formation of lamellipodia and filopodia. The early induction of CTGF was linked to the HGF-mediated alterations of cell morphology. The PP2 inhibitor of Src-family kinases, which regulate focal adhesion turnover, reduced HGF-mediated upregulation of CTGF. In addition, inhibition of the Rho-kinase, which modulates the actin cytoskeleton, impaired CTGF expression. Combination of both inhibitors further decreased CTGF expression. Comparable inhibitory effects were obtained, when CTGF was induced by the combination of HGF and TGF-beta. CONCLUSIONS: We provide evidence for a dual effect of HGF on CTGF regulation in human tubular epithelial cells: transient upregulation of CTGF in the absence of TGF-beta, which was related to alterations of cell morphology, and interference with TGF-beta-mediated CTGF induction after prolonged incubation.  相似文献   
136.
The computed tomography (CT)/discograms and discographic pain provocation reports of 291 clinical patients, 790 discs (mean age, 38; range, 17-79) were collected. The CT/discograms were classified separating anular disruption and degeneration and recording the pain provoked during discography as no pain, dissimilar, similar, or exact reproduction of the patient's clinical pain. Nondegenerated discs usually were found to be painless, and deteriorated discs painful. The proportion of severely degenerated but painless discs increased with age, as did the discs producing dissimilar pain. This may help explain the poor correlation of low-back pain with radiographic degenerative changes reported in previous epidemiologic studies.  相似文献   
137.
138.
139.
World Journal of Surgery - Routine preoperative staging in pancreas cancer is controversial. We sought to evaluate the rates of diagnostic laparoscopy (DLAP) for pancreatic cancer. We queried the...  相似文献   
140.
ContextIt is especially important that patients are well informed when making high-stakes, preference-sensitive decisions like those on the Physician Orders for Life-Sustaining Treatment (POLST) form. However, there is currently no way to easily evaluate whether patients understand key concepts when making these important decisions.ObjectivesTo develop a POLST knowledge survey.MethodsExpert (n = 62) ratings of key POLST facts were used to select items for a POLST knowledge survey. The survey was administered to nursing facility residents (n = 97) and surrogate decision-makers (n = 112). A subset (n = 135) were re-administered the survey after a standardized advance care planning discussion to assess the scale's responsiveness to change.ResultsThe 19-item survey demonstrated adequate reliability (α = 0.72.). Residents' scores (x = 11.4, standard deviation 3.3) were significantly lower than surrogate scores (x = 14.7, standard deviation 2.5) (P < 0.001). Scores for both groups increased significantly after administration of a standardized advance care planning discussion (P < 0.001). Although being a surrogate, age, race, education, cognitive functioning, and health literacy were significantly associated with higher POLST Knowledge Survey scores in univariate analyses, only being a surrogate (P < 0.001) and being white (P = 0.028) remained significantly associated with higher scores in multivariate analyses.ConclusionThe 19-item POLST Knowledge Survey demonstrated adequate reliability and responsiveness to change. Findings suggest the survey could be used to identify knowledge deficits and provide targeted education to ensure adequate understanding of key clinical decisions when completing POLST.  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