首页 | 官方网站   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   1637篇
  免费   124篇
  国内免费   13篇
医药卫生   1774篇
  2022年   10篇
  2021年   24篇
  2020年   71篇
  2019年   21篇
  2018年   26篇
  2017年   29篇
  2016年   20篇
  2015年   29篇
  2014年   78篇
  2013年   71篇
  2012年   79篇
  2011年   102篇
  2010年   105篇
  2009年   82篇
  2008年   74篇
  2007年   95篇
  2006年   71篇
  2005年   55篇
  2004年   63篇
  2003年   53篇
  2002年   30篇
  2001年   29篇
  2000年   36篇
  1999年   22篇
  1998年   15篇
  1997年   15篇
  1996年   7篇
  1995年   12篇
  1994年   12篇
  1993年   15篇
  1992年   5篇
  1991年   3篇
  1990年   13篇
  1989年   4篇
  1988年   3篇
  1987年   3篇
  1986年   4篇
  1985年   68篇
  1984年   52篇
  1983年   67篇
  1982年   48篇
  1981年   61篇
  1980年   44篇
  1979年   16篇
  1978年   16篇
  1976年   5篇
  1975年   6篇
  1973年   2篇
  1971年   1篇
  1966年   1篇
排序方式: 共有1774条查询结果,搜索用时 828 毫秒
1.
目的:探讨单孔胸腔镜下肺癌手术术后胸腔引流时间的影响因素。方法:本研究采用回顾性分析方法,回顾我院2018年01月至2019年12月原发性肺癌患者经单孔胸腔镜手术治疗的病例199例。按照术后胸腔引流时间分为两组,Ⅰ组(术后胸腔引流时间<5天)和Ⅱ组(术后胸腔引流时间≥5天)。对于影响术后胸腔引流时间的可能因素在两组间先采用单因素分析的方法筛选,再将筛选出来的对术后胸腔引流时间可能有意义的影响因素进行二项Logistic多因素回归分析。结果:经单因素分析及二项Logistic多因素回归分析结果显示:年龄≥60岁、手术部位、肺段切除术、胸膜粘连、手术时间≥180 min、术后早期下床活动是术后胸腔引流时间的独立影响因素(P<0.05)。结论:对于具有多个延长术后胸腔引流时间的独立影响因素的患者,应制定个体化管理方案,尽可能减少术后胸腔引流时间,减少住院天数,加快患者康复。  相似文献   
2.
Ovarian carcinoma is one of the most lethal malignancies, but only very few prognostic biomarkers are known. The degradome, comprising proteases, protease non-proteolytic homologues and inhibitors, have been involved in the prognosis of many cancer types, including ovarian carcinoma. The prognostic significance of the whole degradome family has not been specifically studied in high-grade serous ovarian cancer. A targeted DNA microarray known as the CLIP-CHIP microarray was used to identify potential prognostic factors in ten high-grade serous ovarian cancer women who had early recurrence (<1.6 years) or late/no recurrence after first line surgery and chemotherapy. In women with early recurrence, we identified seven upregulated genes (TMPRSS4, MASP1/3, SPC18, PSMB1, IGFBP2, CFI – encoding Complement Factor I – and MMP9) and one down-regulated gene (ADAM-10). Using immunohistochemistry, we evaluated the prognostic effect of these 8 candidate genes in an independent cohort of 112 high-grade serous ovarian cancer women. Outcomes were progression, defined according to CA-125 criteria, and death. Multivariate Cox proportional hazard regression models were done to estimate the associations between each protein and each outcome. High ADAM-10 expression (intensity of 2–3) was associated with a lower risk of progression (adjusted hazard ratio (HR): 0.51; 95% confidence interval (CI): 0.29-0.87). High complement factor I expression (intensity 2–3) was associated with a higher risk of progression (adjusted HR: 2.30, 95% CI: 1.17–4.53) and death (adjusted HR: 3.42; 95% CI: 1.72–6.79). Overall, we identified the prognostic value of two proteases, ADAM-10 and complement factor I, for high-grade serous ovarian cancer which could have clinical significance.  相似文献   
3.
蛋白质组学是研究细胞内所有蛋白质及其动态变化规律的科学,近年来它被广泛应用于生命科学的各个领域.二维聚丙烯酰胺凝胶电泳法(2D PAGE)是蛋白质组学核心技术.就蛋白质组学在皮肤病学基础研究和临床皮肤病中的应用进行综述.  相似文献   
4.
Forty-four isolates of Acinetobacter calcoaceticus var anitratus collected during hospital outbreaks were studied using polyacrylamide gel electrophoresis (PAGE), plasmid analysis, antibiograms and biochemical tests to determine their degree of similarity. Reproducibility tests were also carried out on the PAGE and biochemical techniques to determine their validity when used to compare bacteria of the same type isolated intermittently. PAGE data was analysed densitometrically and isolates compared using a similarity matrix. All methods were able to subdivide the isolates, but results did not always correlate well between methods. Reproducibility data indicated that careful attention to technique is required when organisms are examined by PAGE sequentially. Results suggest that no single biotyping technique is likely to be adequate and that electrophoretic, biochemical and antibiogram data may complement one another and other epidemiological data in the typing of these organisms.  相似文献   
5.
蜂胶提取物对小鼠胸腺肽合成的影响   总被引:2,自引:0,他引:2  
目的:研究蜂胶乙醇提取物黄酮(EEP)对小白鼠衰老过程中胸腺肽合成量的影响。方法:垂直板电泳法。结果:EEP可增加小鼠胸腺肽的合成量。结论:EEP可增强小鼠的免疫力。具有抗衰老作用。  相似文献   
6.
107例在院伤残军人抑郁自评量表调查研究及多因子分析   总被引:5,自引:0,他引:5  
目的了解伤残军人伤残后的心理健康状况。方法用zung’s抑郁自评量表(self rating depressionscale,SDS)为工具,对在院107例特、一等伤残军人进行调查研究。并选择年龄、病程、伤残种类、文化程度、伤残严重度、婚姻等14个因子作自变量,SDS部分作因困变量进行逐步回归分析。结果伤残军人SDS与我国SDS常模比较显示伤残军人分明显增高,二者有极显著统计学意义,并且受X2病程、X12康复疗效、X13参与社会工作等因素影响(P<0.01)。结论伤残军人伤残后存在有明显的心理健康问题,针对性开展一些康复措施,有利于全面康复。  相似文献   
7.
To further understand the processes that lead to the formation of neurofibrillary tangles from paired helical filaments (PHF) in Alzheimer brains, we studied two morphologically distinct fractions of PHF separated on sucrose density gradient. In a fraction with mostly short and non-aggregated PHF, the majority of filaments could be solubilized in SDS. In a fraction containing primarily PHF aggregated into clusters or bundles, sometimes resembling neurofibrillary tangles, filaments were less soluble in SDS. Immunogold labelling with a panel of tau-immunoreactive antibodies demonstrated that N-terminal epitopes of tau were preserved in the short filaments, but were reduced or absent in aggregated filaments. In contrast, C-terminal epitopes were present in both fractions. Furthermore, the accessibility of the microtubule-binding domain to immunolabelling was markedly impaired in short and non-aggregated filaments compared to aggregated filaments. These results are consistent with proteolytic degradation of the N-terminal epitopes and preservation of the C-terminal epitopes and the microtubule-binding domain of tau in the aggregated filaments. Partial proteolysis may be involved in the generation of aggregated PHF in neurofibrillary tangles.  相似文献   
8.
The Pharmacia Multiphor II horizontal electrophoresis chamber is a widespread tool for analysis of PCR products in forensic casework. Up to date, however, there is no protocol for successfully running high-resolution denaturing PAGE (poly-acrylamide gel electrophoresis) on a horizontal electrophoresis chamber. We modified the electrophoresis conditions to make this possible.  相似文献   
9.
Summary The polymorphism of the D1S80 locus has been analyzed in a population sample of 203 unrelated individuals living in Madrid (central Spain) by PCR and subsequent semi-dry discontinuous polyacrylamide gel electrophoresis (Tris-chloride/Tris-glycine buffer system) followed by silver staining, The electrophoretic system described in this study offers high resolution in the separation of the different D1S80 alleles allowing the detection of microvariability around the allele T22 in the spanish population. Twenty different alleles containing 17–40 repeats of the basic 16bp unit were distinguished. The alleles T18 and T24 were found to be relatively common in Spain, as in other populations:, with frequencies of 0.224 and 0.372, respectively. No evidence of significant deviations from Hardy-Weinberg equilibrium was found in these preliminary population data.  相似文献   
10.
神经症的性压抑与心理因素的相关性研究   总被引:1,自引:0,他引:1  
研究神经症患者潜在人格与性压抑和情绪的相关性.方法:对124例神经症患者进行了婚姻质量问卷(性生活、婚姻质量部份)、抑郁自评量表(以下简称SDS)、焦虑自评量表(以下简称SAS)及自编的性生活调查问卷、主题统觉测验(以下简称TAT)测评.结果:1、神经症伴性障碍组TAT潜在人格与对照组相比,在支配、性、援助、躯体社会攻击、财产破坏欲求、自我攻击、情绪变化欲求和情绪言语攻击性、躯体社会攻击、引诱、缺乏、丧失、灾害、丧失支持、躯体伤害压力上均较对照组显著增高,而成就欲求下降(P<005-001);与神经症无性障碍组相比,神经症伴性障碍组的成就、支配、教养、性欲求得分显著增高,情绪言语攻击欲求得分下降(P<001~005);2、神经症伴性障碍组的性生活质量低,性频度、性后快感均低.3、SDS、SAS与TAT中的负性欲求呈明显的相关性,性行为调查与婚姻质量量表中的性行为呈正相关.结论:神经症的性压抑与其潜在人格有密切的相关性.  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-23

京公网安备 11010802026262号