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   22151篇
  免费   1368篇
  国内免费   740篇
耳鼻咽喉   41篇
儿科学   459篇
妇产科学   211篇
基础医学   5371篇
口腔科学   251篇
临床医学   2231篇
内科学   3788篇
皮肤病学   437篇
神经病学   1121篇
特种医学   416篇
外国民族医学   3篇
外科学   1383篇
综合类   3379篇
现状与发展   5篇
预防医学   1693篇
眼科学   155篇
药学   1632篇
  8篇
中国医学   232篇
肿瘤学   1443篇
  2024年   27篇
  2023年   260篇
  2022年   620篇
  2021年   727篇
  2020年   586篇
  2019年   572篇
  2018年   543篇
  2017年   559篇
  2016年   598篇
  2015年   627篇
  2014年   965篇
  2013年   1384篇
  2012年   976篇
  2011年   1114篇
  2010年   821篇
  2009年   839篇
  2008年   848篇
  2007年   946篇
  2006年   836篇
  2005年   849篇
  2004年   786篇
  2003年   753篇
  2002年   627篇
  2001年   573篇
  2000年   563篇
  1999年   452篇
  1998年   474篇
  1997年   489篇
  1996年   440篇
  1995年   517篇
  1994年   475篇
  1993年   431篇
  1992年   413篇
  1991年   400篇
  1990年   335篇
  1989年   235篇
  1988年   254篇
  1987年   204篇
  1986年   162篇
  1985年   316篇
  1984年   207篇
  1983年   144篇
  1982年   95篇
  1981年   68篇
  1980年   37篇
  1979年   32篇
  1978年   31篇
  1977年   13篇
  1976年   9篇
  1974年   6篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Summary We have identified cells which secrete human chorionic gonadotropin (HCG) of cultures if first trimester placental villi. As a first step, we identified epithelial cells using a new monoclonal antibody. We then added HCG antibodies to the cultured cells. We found that syncytiotrophoblast (and not cytotrophoblast), Hofbauer cells and some mesenchymal cells stained with HCG antibodies.  相似文献   
82.
目的:探讨利福平致急性肾功能衰竭的临床病理特点及其发病机制。方法:对3例因利福平所致的急性肾衰竭患者的临床、肾脏病理进行分析,并采用抗人球蛋白试验方法检测患者的抗利福平抗体。结果:3例患者均有前驱感染史,临床主要表现为发热、胃肠道症状,随即出现无尿,伴随肾功能损害、血小板减低及溶血性贫血,部分伴有肝功能损害。肾活检3例均为急性肾小管坏死。3例的血清抗利福平抗体检测均为阳性。结论:利福平可引起急性肾衰竭,对应用利福平的患者应加强对肾功能的监测,肾脏病理及血清抗利福平抗体的检测有助于确诊。  相似文献   
83.
Phenotypic analysis of lymphoproliferative disorders is now considered mandatory for accurate classification which is the basis for optimum patient management. This is presently carried out in most cases using a range of antibodies recognizing B and T-cell antigens effective in paraffin sections, and an antibody to CD3 is currently a key member of such panels, indicating T-cell phenotype. Current antibodies to CD3 are polyclonal with the inherent disadvantages of this type of reagent compared to monoclonal antibodies. In this study, we have used a recombinant fusion protein representing part of the epsilon subunit of the CD3 molecule to generate a novel monoclonal antibody (NCL-CD3-PS1) effective in paraffin sections. The antibody has been characterized biochemically and by immunohistochemistry using a wide range of normal and pathological tissues. Lineage and phenotype specificity have been supported in our study and results from other laboratories are awaited with interest.  相似文献   
84.
We raised polyclonal and monoclonal antibodies against rat recombinant HPC-1/syntaxin 1A lacking a transmembrane domain. The polyclonal antibody recognized two major bands at 35 and 40 kDa from rat brain membranes. A hybridoma clone designated 14D8, however, recognized only one band at 35 kDa. A polyclonal antibody detected recombinant syntaxin 1B, as well as HPC-1/syntaxin 1A on an immunoblot, whereas 14D8 recognized recombinant HPC-1/syntaxin 1A, but not syntaxin 1B. Therefore, 14D8 is specific for HPC-1/syntaxin 1A. Using this monoclonal antibody, we investigated the expression of HPC-1/syntaxin 1A in the rat hippocampal membranes. HPC-1/syntaxin 1A was present even in the embryonic d 19 (E19) hippocampal membranes, and it increased during the next two postnatal wk. Pyramidal cell axons were intensely stained with the 14D8 monoclonal antibody, suggesting that HPC-1/syntaxin 1A was not restricted to the presynaptic terminal. Furthermore, we investigated the phosphorylation of HPC-1/syntaxin 1A in the rat brain membranes. HPC-1/syntaxin 1A affinity-purified on a 14D8 IgG-coupled column was recognized by antiphophoserine antibody, but not by antiphosphotyrosine and phosphothreonine antibodies.  相似文献   
85.
脑囊虫病人血清、脑脊液中抗体在MRI各期的变化   总被引:1,自引:0,他引:1  
目的 检测脑囊虫病人血清和脑脊液中抗体在MRI各期的变化。方法 用抑制性ELISA法检测血清及脑脊液中的抗体。同时根据MRI表现将病例分为活动期、退变期、非活动期。结果 在69个病例中,脑脊液中抗体阳性率分别是:活动期75.00%,退变期62.50%,非活动期17.24%;血清中是81.25%、16.67%、22.22%。在相应各期中,脑脊液和血清抗体阳性率无显著性差别。结论 在影像学的不同时期抗体阳性率存在明显的变化。  相似文献   
86.
目的:通过相应的测定对自动化血库系统适用性和安全性进行全面评价,并对输血相容性检测方法与常规手工方法进行全面对比.方法:使用人工设计的各种样本对仪器进行特异性、灵敏度及抗干扰试验的对比评估,以及对临床常规9108例标本进行ABO正反定型,Rh(D)测定及抗体筛检测定,并对相应结果进行对比分析.结果:对人工设置的各种测定标本,在特异性、灵敏度和抗干扰试验中,测定结果均能达到设计要求,并优于手工Polybrene方法.ABO血型测定9108份,除正反定型不符.228份,报告NTD给予提示外,其它测定血型全部与报告血型相符;Rh(D)所测结果为4份NTD,9104份结果全部相符.抗体筛检测定9108份,抗筛阳性383份,使用同一种抗筛细胞进行手Polybrene方法抗筛测定阳性仅为228份,统计学有显著性意义(P<0.005).结论:ABS2000应用的固项检测技术具有较高的敏感度,能检测出较弱的IgG类的不规则及自身抗体,以上检测结果及统计情况与国外相关报道情况相符,此仪器在临床检测中使用可以达到保证安全检测的目的.  相似文献   
87.
Intravenous immunoglobulin (IVIG) products are derived from pooled human plasma and have been used for the treatment of primary immunodeficiency disorders for more than 24 years. Shortly after their introduction, IVIG products were also found to be effective in the treatment of autoimmune and inflammatory disorders. Over the past 2 decades, the list of diseases where IVIG has a demonstrable beneficial effect has grown rapidly. These include Kawasaki disease, Guillain-Barre syndrome, myasthenia gravis, dermatomyositis and demyelinating polyneuropathy. Recently, we have described a beneficial effect on the reduction of anti-HLA antibodies with subsequent improvement in transplantation of highly HLA-sensitized patients as well as a potent anti-inflammatory effect that is beneficial in the treatment of antibody-mediated rejection (AMR). These advancements have enabled transplantation of patients previously considered untransplantable. These studies and relevant mechanism(s) of action will be discussed here.  相似文献   
88.
A novel enzyme immunoassay of anti-insulin IgG in human serum is described. A serum sample containing anti-insulin IgG was treated with dextran-charcoal at pH 6.0 to remove endogenous insulin and subsequently incubated with dinitrophenyl biotinyl nonspecific rabbit IgG-insulin conjugate. The reaction mixture was further incubated with a rabbit (antidinitrophenyl bovine serum albumin) IgG-coated polystyrene ball to trap the complex formed between anti-insulin IgG and the conjugate. After washing to eliminate nonspecific IgG in the test serum, the polystyrene ball was incubated with dinitrophenyl-L-lysine to elute the complex. The eluate was incubated with an avidin-coated polystyrene ball. Finally, the amount of human anti-insulin IgG in the complex trapped onto the avidin-coated polystyrene ball was measured by incubation with rabbit (antihuman IgG (γ-chain)) Fab'-peroxidase conjugate. This enzyme immunoassay was 1,000-fold more sensitive than the conventional enzyme immunoassay, in which an insulin-bovine serum albumin-coated polystyrene ball was incubated with a serum sample containing anti-insulin IgG and subsequently with rabbit (antihuman IgG (γ-chain)) Fab'-peroxidase conjugate. The principle of the novel enzyme immunoassay can be used to more sensitively measure antibodies for most kinds of haptens and antigens than the conventional enzyme immunoassay.  相似文献   
89.
90.
应用ELISA测定了54例类风湿性关节炎患者、99例非类风湿性关节炎患者以及100例正常人的血清Ⅱ型胶原抗体,结果阳性率分别为90.7%、0、0.54例类风湿性关节炎患者中有7例血清类风湿因子为阴性而Ⅱ型胶原抗体为阳性,且病程均在半年之内。结果表明:Ⅱ型胶原抗体的检测对类风湿性关节炎具有特异性诊断和早期诊断的临床意义。  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