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   45103篇
  免费   3997篇
  国内免费   1713篇
耳鼻咽喉   298篇
儿科学   822篇
妇产科学   1325篇
基础医学   9444篇
口腔科学   1658篇
临床医学   3647篇
内科学   4784篇
皮肤病学   1239篇
神经病学   2730篇
特种医学   972篇
外国民族医学   20篇
外科学   3094篇
综合类   6697篇
现状与发展   12篇
一般理论   12篇
预防医学   3571篇
眼科学   938篇
药学   5213篇
  20篇
中国医学   1058篇
肿瘤学   3259篇
  2024年   58篇
  2023年   491篇
  2022年   1000篇
  2021年   1458篇
  2020年   1268篇
  2019年   1318篇
  2018年   1294篇
  2017年   1415篇
  2016年   1492篇
  2015年   1522篇
  2014年   2363篇
  2013年   3276篇
  2012年   2358篇
  2011年   2590篇
  2010年   2248篇
  2009年   2061篇
  2008年   2025篇
  2007年   2166篇
  2006年   2046篇
  2005年   1853篇
  2004年   1727篇
  2003年   1557篇
  2002年   1324篇
  2001年   1155篇
  2000年   991篇
  1999年   884篇
  1998年   867篇
  1997年   824篇
  1996年   780篇
  1995年   735篇
  1994年   634篇
  1993年   595篇
  1992年   530篇
  1991年   478篇
  1990年   362篇
  1989年   366篇
  1988年   312篇
  1987年   234篇
  1986年   213篇
  1985年   374篇
  1984年   321篇
  1983年   220篇
  1982年   251篇
  1981年   198篇
  1980年   152篇
  1979年   99篇
  1978年   100篇
  1977年   63篇
  1976年   61篇
  1975年   33篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
本文应用HPV-PCR技术和DNA杂交技术对76例宫颈鳞癌标本进行了HPV-DNA的研究,发现HPV-DNA存在率为90.79%(69/76),主要类型为HPV16和18。多酶切SouthernBlot杂交证实在宫颈癌中92.56%的HPV-DNA发生变异,说明HPV-DNA的基因变异与其致癌作用密切相关。PCR结果证实HPV-E6片段在宫颈癌组织中常可出现,推测可能是致癌的关键片段之一。因此,检测宫颈癌组织中HPV-DNA的完整性、关键基因片段的存在与否,可能对于病变恶变的预测有一定的意义  相似文献   
92.
报告1100名35岁以上农民冠心病患病率及易患因素的调查结果。全组中检出冠心病15例,其中陈旧心肌梗塞3例、心绞痛7例、心律失常及不典型心绞痛伴有心电图缺血型改变者5例,冠心病现患率为1.36%。另有单纯ST-T 缺血型改变84例,各种严重心律失常36例,未计入冠心病现患率之内.经单变量线性相关及多变量Logistic 函数分析结果,选出有意义的冠心病易患因素有甘油三酯、年龄及收缩期血压增高,以及血浆高密度脂蛋白胆固醇的降低。  相似文献   
93.
We examined 161 human tissue samples using the spot hybridization technique with nonradioactive labeled DNA probes of human papillomavirus (HPV). Whole cells were spotted on nitrocellulose filters; DNA of the cells was denatured and fixed to the filter. Then the DNA spots were hybridized to nonradioactive labeled DNA and monitored by a sandwich immunoenzymatic reaction. This technique is simple, sensitive, specific, requires no special equipment, and can be used in clinical settings. HPV DNA was found in 92% of samples in which, on the basis of histologic and colposcopic criteria, its presence was suspected, as well as in 31 samples where it was not suspected.  相似文献   
94.
报告2687例血清甲状腺球蛋白抗体和甲状腺微粒体抗体的放射免疫测定结果,九类病人的抗体阳性率如下:甲状腺正常病人12.6(30/239)、孤立甲状腺结节16.9%(62/383)、弥漫性甲状腺肿35.4%(226/638)、多结节甲状腺肿54.7%(104/190)、甲亢未治疗77.7%(404/520)、甲亢治疗中67.2%(218/345)甲亢临床已治愈60.3(102/169),原发性甲减80.8%(118/146)、亚急性甲状腺炎35.1%(20/57)。各种甲状腺疾病的总阳性率为51.2%(1254/2448)。对甲状腺自抗体阳性在甲状腺疾病的诊断、治疗、和预后判断上的意义进行了讨论。  相似文献   
95.
Two strains of T. rubrum and one strain of T. mentagrophytes were inoculated into human skin grafted onto BALB/c nude mice by the needle puncture method. Infection was established in 1 of the 10 animals inoculated with fluffy colony type T. rubrum, 2 of the 10 animals inoculated with powdery colony type T. rubrum, and 7 of the 10 animals inoculated with granular colony type T. mentagrophytes, suggesting that the skin grafts are infectible by anthropophilic and zoophilic strains of dermatophytes. T. rubrum infection continued for a maximum of 9 weeks and T. mentagrophytes infection for more than 11 weeks. In the animals inoculated with T. mentagrophytes, fungal elements were localized in the stratum corneum of the human skin grafts. In the acute stage, microabscesses consisting of neutrophils were observed under the stratum corneum in contact with fungal elements; in the chronic stage, epidermal thickening and infiltration, mainly consisting of histiocytes and a smaller number of lymphocytes, was noted in the upper and middle dermis. Ultrastructural findings from the parasites were similar to those of dermatophytosis in man. This experimental system should be useful as a model of chronic dermatophyte infection in the human skin.  相似文献   
96.
The 11C-labelled benzodiazepine antagonist Ro 15–1788 (flumazenil) and positron emission tomography (PET) were used to determine quantitative characteristics of benzodiazepine receptor binding in the neocortex of healthy young men. Saturating doses of unlabelled flumazenil administered i.v., before or together with the ligand-reduced 11C-flumazenil accumulation in the neocortex by about 90 per cent. Saturating doses of unlabelled flumazenil had little effect on the accumulation of radioactivity in the benzodiazepine receptor-poor regions such as pons or white matter. By giving graded doses of unlabelled flumazenil together with the tracer, saturation isotherms were obtained allowing the calculation of receptor density (Bmax) and equilibrium dissociation constant (Kd) values on the basis of certain assumptions Bmax values were in the order of 90 pmol/g and Kd values in the order of 10 nM in the neocortex. Scatchard and Hill plots of the radioactivity data indicated that 11C-flumazenil binds to saturable sites of a homogeneous population. The data indicate that intravenous doses of 1 or 2 mg flumazenil result in a benzodiazepine receptor occupancy of about 50 per cent. The method described should be useful for studying regional differences in benzodiazepine receptor characteristics in the living human brain in healthy subjects and neuropsychiatric disorders, and also in relation to treatment with drugs interacting with benzodiazepine receptors.  相似文献   
97.
本文介绍了《正常人体学基础》教材的特点,讨论了本学科教学应注意的问题,强调了要充分地使用标本模型、挂图及多媒体教学,讨论了本学科的学习方法.  相似文献   
98.
Human prespermatogenesis between the 8th week of pregnancy and six months after birth was studied in testis material of 28 male foetuses from spontaneous abortions and 81 infants who died from sudden infant death. The foetuses and infants were grouped in 10 age groups. A first steep raise in the numbers of germ cells per 20 tubular cross sections from 22.3 in the first group up to 69.5 in group 3 was observed, i.e. up to the end of the 22nd week of pregnancy. Thereafter, a continuous decrease could be observed modulated by a second slighter increase during the first 4 months after birth. The ratio of germ cells and immature Sertoli cells improves from about 1:20 at the beginning to 1:8 in group 3; afterwards it changes in favour of the immature Sertoli cells down to 1:140 at the end of the study. The initial augmentation of germ cells is interpreted as the effect of a first proliferation wave comparable to that of M-prospermatogonia in other species. The decrease of germ cells is due to the stop of germ cell proliferation and simultaneous high proliferative activity of the immature Sertoli cells.  相似文献   
99.
CG Teo 《Oral diseases》2002,8(S2):88-90
Oral hairy leukoplakia (OHL) and Kaposi's sarcoma (KS) are commonly encountered in the HIV-infected patient. A unique feature of OHL is non-cytolytic high level of replication of Epstein–Barr virus (EBV) in the glossal epithelium. The expression of viral-encoded anti-apoptotic proteins concomitant to replicative proteins probably underlies this phenomenon. The question of whether OHL arises from activation of EBV latent in the tongue, or from superinfection by endogenous EBV shed via non-glossal sites or by exogenous EBV remains unresolved. Human herpesvirus 8 (HHV8) is now seen as necessary but not sufficient cause of KS. Expression of HHV8-encoded oncogenic proteins in endothelial cells probably explains the aberrant proliferation of these cells in KS lesions. Studies into why KS is so commonly observed at the palate in HIV-infected patients may provide important clues to its pathogenesis.  相似文献   
100.
本文综述本校传染病学教研室1955~1995年间所取得的科研成果。内容包括10余种传染病与寄生虫病的临床和基础研究,其中以华支睾吸虫病、恙虫病等有广东特色的传染病以及伤寒、痢疾、病毒性肝炎等影响人民健康最普遍的传染病为重点。反映了建国以来各个时期本教研室对防治这些传染病所作的贡献。所取得的成果,相当一部分通过多年来的验证,已获得广大传染病工作者所认同或列为常规,部分已获得部委级奖励。现在重温这些成果,可能起承前启后的意义。  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