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   64754篇
  免费   6671篇
  国内免费   4171篇
耳鼻咽喉   483篇
儿科学   918篇
妇产科学   619篇
基础医学   7056篇
口腔科学   1328篇
临床医学   8474篇
内科学   8577篇
皮肤病学   809篇
神经病学   2942篇
特种医学   2423篇
外国民族医学   30篇
外科学   5899篇
综合类   11951篇
现状与发展   16篇
一般理论   5篇
预防医学   5729篇
眼科学   1305篇
药学   7359篇
  84篇
中国医学   4867篇
肿瘤学   4722篇
  2024年   299篇
  2023年   1137篇
  2022年   2802篇
  2021年   3540篇
  2020年   2722篇
  2019年   2242篇
  2018年   2263篇
  2017年   2278篇
  2016年   2162篇
  2015年   3234篇
  2014年   3830篇
  2013年   4018篇
  2012年   5335篇
  2011年   5827篇
  2010年   4087篇
  2009年   3388篇
  2008年   3867篇
  2007年   3722篇
  2006年   3358篇
  2005年   3012篇
  2004年   2163篇
  2003年   2090篇
  2002年   1757篇
  2001年   1297篇
  2000年   1080篇
  1999年   865篇
  1998年   501篇
  1997年   476篇
  1996年   323篇
  1995年   311篇
  1994年   269篇
  1993年   163篇
  1992年   189篇
  1991年   154篇
  1990年   144篇
  1989年   111篇
  1988年   116篇
  1987年   77篇
  1986年   65篇
  1985年   42篇
  1984年   21篇
  1983年   22篇
  1981年   17篇
  1979年   40篇
  1977年   13篇
  1975年   12篇
  1973年   15篇
  1971年   11篇
  1969年   20篇
  1966年   11篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
21.
品酒之趣     
点点酒意 带来神来之笔 酒赐予吾灵气。常酒后行文,数部拙著于案,盖盖于此!或得缪赞,以得酒资而侃之。  相似文献   
22.
Polymorphism p53 codon-72 and invasive cervical cancer: a meta-analysis.   总被引:4,自引:0,他引:4  
OBJECTIVES: Although some studies have reported that the arginine isoform on codon 72 of p53 increases the susceptibility to invasive cervical cancer, such data remain controversial. The objective of this study was to quantitatively summarize the evidence for such a relationship. METHODS: Our data sources consisted of a MEDLINE search of the literature published before December 2002, bibliography review, and expert consultation. Thirty-seven studies met the inclusion criteria. Information on sample size, study design, Hardy-Weinberg equilibrium, and method of genotype determination was abstracted by two reviewers using a standardized protocol. The overall odds ratio (OR) of the p53 gene on invasive cervical cancer was estimated using the Mantel-Haenzel method. RESULTS: The overall OR (95% confidence interval) for cervical cancer among those with the homozygous mutant (Arg/Arg) was 1.2 (1.1-1.3, P=0.001) compared with those with the heterozygous mutant (Arg/Pro). By a cellular type of cervical cancer, the overall OR among those with Arg/Arg was statistically significant in adenocarcinomas (1.7, 1.1-2.6, P=0.024), but not in squamous cell carcinomas (1.1, 0.9-1.2, P=0.960), compared with Pro/Pro. Compared with Arg/Pro, the OR among those with Arg/Arg was statistically significant in HPV types 16 (1,5, 1.2-2.0, P=0.002). CONCLUSIONS: Overall, the p53 gene was associated with increased risk for invasive cervical cancer. However, the risk varied by country, cellular, and HPV type.  相似文献   
23.
Background: Cicatricial deformation in child burn of hand often leads to severe squaelae. According to different causes of disease , different plastic surgery were adopted .The key of operation lies in skin repairing , articulation dealing, and thumb correcting, which aim is to resume normal longitudinal and transverse arcs ,holding and clenching ability.  相似文献   
24.
寒冷干燥地区平时火器伤的早期处理   总被引:3,自引:3,他引:0  
目的 探讨寒冷干燥地区平时火器伤伤情特点与早期救治方法。方法 对 1991年 1月— 2 0 0 2年 12月间 40例火器伤病人的临床救治进行回顾分析。结果  2 4例枪伤中 ,2 0例一期缝合伤口 ,均一期愈合 ,另外 4例只清创未一期缝合的伤口 ,3例愈合 ,1例感染 ;4例骨折内固定均愈合良好 ,无骨髓炎发生。 16例炸伤病人局部软组织损伤及污染比枪弹伤重 ,14例一期缝合伤口中 ,10例一期愈合 ,4例感染 ,骨折内固定 2例 ,均愈合良好 ,无骨髓炎发生。结论 寒冷干燥地区火器伤早期伤道清创时限可适当延长 ,在平时火器伤的救治中 ,对软组织条件较好的创面 ,早期清创后可一期闭合伤口和骨折内固定 ,这样可减少感染和伤残 ,促进康复  相似文献   
25.
目的 探讨老年腰椎间盘突出症的特点与手术治疗效果.方法 对62例老人腰椎间盘突出症患者的临床与病理特点进行分析.均行腰椎后路椎板减压髓核摘除术,其中小切口开窗35例,半椎板切除20例,全椎板切除7例,根据手术前后JOA评分评价手术疗效.结果 老年腰椎间盘突出症病理以髓核组织的脱水,纤维环的破裂,小关节囊、周围韧带及软骨终板退变为主要特点.临床特点为下肢疼痛多发,腰部活动受限较多;双下肢神经系统检查肌力下降明显,生理反射改变明显.62例平均随访1.9年,JOA评分术后平均改善率为68.9%,手术前后JOA评分比较差异有显著性意义(P<0.05).结论 老年腰椎间盘突出症患者病程长,体征多,病理改变明显,行腰椎后路椎板减压髓核摘除术,手术效果满意.  相似文献   
26.
Meng Q  Chen W 《Planta medica》1988,54(1):48-49
A new 6-oxygenated coumarin, pygmaeoherin, was isolated from roots of PYGMAEOPREMNA HERBACEA. Its structure was determined by spectroscopic methods. An NOE experiment played an important role in confirming the structure.  相似文献   
27.
Globoid cell leukodystrophy (GLD, Krabbe disease) is a severe demyelinating disease caused by a genetic defect of beta-galactocerebrosidase (GALC). To date treatment to GLD is limited to hematopoietic stem cell transplantation. Experimental approaches by means of gene therapy in twitcher mouse, an authentic murine model of human GLD, showed significant but only marginal improvements of the disease. To clarify whether the introduction of GALC could provide beneficial effects on the oligodendrocytes in GLD, we transduced twitcher oligodendrocytes by stereotactically injecting recombinant retrovirus encoding GALC-myc-tag fusion gene into the forebrain subventricular zone of neonatal twitcher mouse. In vivo effects of exogenous GALC on twitcher oligodendrocytes were studied histologically by combined immunostaining for the myc-epitope and the oligodendroglial specific marker, pi form of glutathione-S-transferase, at around 40 days of age. We show here that GALC transduction led to dramatic morphological improvement of the twitcher oligodendrocytes comparing with those in untreated twitcher controls. This study provided direct in vivo evidence that GALC transduction could prevent or correct aberrant morphology of oligodendrocytes in GLD which may be closely related to the dysfunction and/or degeneration of oligodendrocytes and the demyelination in this disease.  相似文献   
28.
Obstructive sleep apnea has traditionally been viewed as a structural disease. A multitude of systemic endocrine and cardiovascular abnormalities have been previously attributed to the prevalence of obesity in these patients. A growing body of clinical evidence, however, points to a relationship between sleep apnea and its systemic abnormalities independent of obesity. We hypothesize that this association is based on a maladaptive autonomic response of chemoreceptors, reacting to the hypoxia, hypercapnia, and acidosis of sleep apnea. The elevated sympathetic response triggers an inflammatory cascade that results in a myriad of downstream consequences including insulin resistance, hypertension, diabetes, atherosclerosis and metabolic syndrome. The sympathetic bias and endocrine disturbances may further exacerbate sleep disturbance in a potentially pernicious cycle. Our proposal may extend to any chronic respiratory or metabolic conditions that manifest hypoxia, hypercapnia, and acidosis and elicit a maladaptive autonomic and inflammatory response.  相似文献   
29.
Rapid leukocyte integrin activation by chemokines   总被引:12,自引:0,他引:12  
Summary: Chemokines control selective targeting of circulating leukocytes to the microvasculature by triggering inside-out signal transduction pathways leading to integrin-dependent adhesion. Integrin activation by chemokines is very rapid, is downmodulated within minutes and appears to involve both enhanced heterodimer lateral mobility on the plasma membrane, facilitating encounters with dispersed ligand, as well as induction of a high-affinity state. These two modalities of integrin activation by chemokines involve distinct signaling pathways in the cell, yet complement each other functionally, allowing binding of rolling cells under conditions of low as well as high ligand density. Recent data show that chemokines generate both pro- and anti-adhesive intracellular signaling events, whose equilibrium is likely to be relevant to the kinetics of adhesion and de-adhesion, and to cell movement during diapedesis and chemotaxis. Importantly, chemokines utilize different signaling mechanisms to modulate the activity of distinct integrin subtypes. These recent advances suggest that chemokines may regulate adhesive responses of immune cells based not only on patterns of chemokine receptor expression, but also on variable signaling pathways that can modulate the pro-adhesive responses of leukocytes as a function of their differentiated state, and of the local microenvironment.  相似文献   
30.
M R Fortson  J R Scott  T Yun  D Vapnek 《Virology》1979,96(1):332-334
The kanamycin resistance determinant in P1Km lies between am33 and gene 2 on the P1 genetic map. This is within the invertible region (C loop) of P1 DNA.  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