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   388767篇
  免费   35639篇
  国内免费   26792篇
耳鼻咽喉   3570篇
儿科学   4501篇
妇产科学   5374篇
基础医学   45362篇
口腔科学   6526篇
临床医学   53461篇
内科学   57101篇
皮肤病学   3786篇
神经病学   20683篇
特种医学   14331篇
外国民族医学   228篇
外科学   38952篇
综合类   64893篇
现状与发展   89篇
一般理论   31篇
预防医学   26430篇
眼科学   10931篇
药学   40098篇
  434篇
中国医学   22765篇
肿瘤学   31652篇
  2024年   1288篇
  2023年   5881篇
  2022年   15250篇
  2021年   19178篇
  2020年   14352篇
  2019年   12539篇
  2018年   13140篇
  2017年   11998篇
  2016年   11183篇
  2015年   17141篇
  2014年   21527篇
  2013年   19393篇
  2012年   28472篇
  2011年   31920篇
  2010年   20928篇
  2009年   16455篇
  2008年   21437篇
  2007年   21377篇
  2006年   21043篇
  2005年   20071篇
  2004年   13092篇
  2003年   12055篇
  2002年   10403篇
  2001年   8986篇
  2000年   9285篇
  1999年   9630篇
  1998年   5771篇
  1997年   5800篇
  1996年   4557篇
  1995年   4084篇
  1994年   3345篇
  1993年   2185篇
  1992年   2918篇
  1991年   2497篇
  1990年   2189篇
  1989年   1936篇
  1988年   1604篇
  1987年   1392篇
  1986年   1143篇
  1985年   946篇
  1984年   543篇
  1983年   392篇
  1982年   254篇
  1981年   248篇
  1980年   195篇
  1979年   238篇
  1978年   92篇
  1977年   99篇
  1974年   105篇
  1973年   86篇
排序方式: 共有10000条查询结果,搜索用时 8 毫秒
61.
Delta hepatitis virus infection in China   总被引:1,自引:0,他引:1  
To assess the prevalence, epidemiological features and prognostic implications of hepatitis D (Delta) in Sichuan Province, The People's Republic of China, 649 sera (515 from HBsAg positive patients and 134 from HBsAg negative subjects) were tested by radioimmunoassay (RIA) for antibody to the hepatitis D virus (anti-HD). Forty-seven sera (7.2%) showed some degree of reactivity. Serial dilutions of these sera indicated that prozoning was not responsible for the equivocal results. Thirty-four of the 47 sera were submitted under code to a second laboratory for independent analysis. According to those results anti-HD antibodies were detected in four of these sera. The overall prevalence of anti-HD in the HBsAg positive patients therefore was 0.8% (4/515). On the basis of clinical, biochemical and histological data 427 HBsAg positive sera were further divided into acute Type B hepatitis, chronic Type B hepatitis, healthy carrier state and hepatocellular carcinoma (HCC) subgroups. Two of 65 (3.1%) anti-HD positive sera belonged to the acute Type B hepatitis group; one of 104 (0.9%), the chronic Type B hepatitis group and one of 246 (0.4%), the healthy carrier group. No antibody was detected in sera from 12 HBsAg positive HCC patients. All HBsAg negative patients were negative for anti-HD antibody. The results of this study indicate that despite a high prevalence of hepatitis B virus infection, positive serology for delta virus is uncommon in Sichuan Province, The People's Republic of China.  相似文献   
62.
63.
Bradyarrhythmia requiring permanent pacing after heart transplantation remains a common problem. Sinus node dysfunction is the most common indication, and late onset of atrioventricular (AV) block has rarely been reported. We report the case of a patient who developed advanced AV block at 41 months after transplantation. Right bundle branch block with progressive increase of QRS complex duration was noted in serial electrocardiograms. At the time of late AV block development, the patient did not have acute rejection and coronary angiogram was normal. The mechanism of late onset of AV block is unclear, but it may be caused by progressive conduction.  相似文献   
64.
65.
本文报道青霉素配伍利多卡因后的药物动力学及生物利用度研究结果,证明利多卡因对青霉素的生物利用度无影响,且可促进青霉素的吸收,为良好的青霉素无痛溶媒,建议推广使用。  相似文献   
66.
In a genetic epidemiology study of a trait, prior to collecting genotype data the foremost task is to test for familial aggregation and examine heritability. Recently, functional traits have drawn attentions from investigators. Here, to test for familial aggregation of a functional trait in the family studies, a test constructed based on the leading functional principal component of heritability, which is a summary measure of temporal genetic variation in a functional trait, is proposed. The p‐value of the test can be approximated by a permutation procedure given the family structure. The asymptotic distribution of the test statistic is derived. Simulations are carried out to examine the size and the power of the test. The proposed methods are applied to the total cholesterol data in the Framingham Heart Study. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   
67.
补肾益气逐浊法治疗ABO溶血致习惯性流产的临床研究   总被引:3,自引:0,他引:3  
目的观察补肾益气逐浊法治疗ABO溶血所致习惯性流产的临床疗效。方法将152例患者随机分为两组,治疗组98例,用补肾益气逐浊法,选用黄芪、菟丝子及蚕砂颗粒剂口服;对照组54例,口服胸腺肽肠溶胶囊等。结果在降低血清抗体效价方面,治疗组总有效率为95.9%,对照组为51.9%;在妊娠疗效方面,治疗组总有效率为95.9%,对照组为42.1%。治疗组疗效明显优于对照组(P〈0.01)。结论补肾益气浊法治疗ABO溶血所致的习惯性流产疗效显著。  相似文献   
68.
The first universal hepatitis B vaccination program for newborns in the world was launched in Taiwan in July 1984. Most studies on the effectiveness of hepatitis B vaccination focused on the seroprevalence of HBs Ag among children under 14 years old. Only few studies focused on the seropositivity of anti-HBs among adolescents aged 15–18 years old. The present study aimed to evaluate the impact of the nationwide hepatitis B vaccination program on the immunity to HBV infection and the necessity of boost among adolescents. In this study including eight annual seroprevalence surveys from 2000 to 2007, 2342 college entrants (1589 15-year-olds in group I and 753 18-year-olds in group II) and 1851 university freshmen (18-year-olds in group III) participated. Subjects identified anti-HBs, HBs Ag and anti-HBc negative were given boost three doses of HBV vaccine. The HBs Ag seroprevalence was 11.6%, 3.5% and 1.0% for participants who were born before 1984, 1984–1986 and after 1986. The anti-HBs-seropositive rates were significantly higher in group II (83.1%) than in group I (53.0%) and group III (53.5%). All 572 participants who were seronegative for anti-HBs, HBs Ag and anti-HBc became anti-HBs-seropositive after catch-up vaccination. It is concluded that the anti-HBs-seropositive rate decreased to 50% in 15 years after vaccination, and boost vaccination was 100% effective. The necessity and age for boost among anti-HBs negative adolescents and the timing of the first immunization should be further evaluated.  相似文献   
69.
目的 观察脂质体阿霉素联合治疗高龄非霍奇金淋巴瘤患者的有效性和安全性.方法 应用脂质体阿霉素联合COP为主的方案化疗或联合利妥昔单抗等其他治疗方案治疗34例患者,观察患者应用脂质体阿霉素过程中及其后的毒副反应及疗效.结果 全组34例患者共接受176个疗程化疗,平均每个患者累计应用脂质体阿霉素127.0 mg治疗,总有效率(CR+PR)为88.2%(30/34),其中CR 24例(70.6%),PR 6例(17.7%),SD 1例(2.9%),PD 3例(8.8%).毒副反应主要为骨髓抑制,未出现严重感染.心脏毒性发生率14.7%(5/34),无化疗相关死亡.结论 脂质体阿霉素联合治疗高龄非霍奇金淋巴瘤具有较高的安全性和有效性.  相似文献   
70.
现代医学200词——138.黏附分子   总被引:1,自引:0,他引:1  
喻磊  王心 《日本医学介绍》2005,26(10):479-480
所谓黏附分子是指存在于细胞表面,参与细胞间或细胞与细胞外基质的粘附的分子群的总称。广义来说,纤维连结蛋白、层粘连蛋白、透明质酸等细胞外基质的构成成分也是由细胞分泌并存在于细胞表面,也可归入黏附分子的范畴。但狭义所指的黏附分子是指贯通细胞膜的糖蛋白或构成细胞膜的糖脂质。膜贯通型糖蛋白黏附分子按其构造特征可分为若干家族。在免疫系统中的黏附分子主要分为整合素家族、免疫球蛋白超家族、选择素家族、钙粘素家族、连接蛋白家族以及唾液粘蛋白家族等。  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