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   860篇
  免费   54篇
  国内免费   15篇
耳鼻咽喉   29篇
儿科学   46篇
妇产科学   21篇
基础医学   104篇
口腔科学   15篇
临床医学   98篇
内科学   176篇
皮肤病学   6篇
神经病学   29篇
特种医学   73篇
外国民族医学   1篇
外科学   113篇
综合类   36篇
预防医学   47篇
药学   61篇
中国医学   3篇
肿瘤学   71篇
  2023年   3篇
  2022年   13篇
  2021年   15篇
  2020年   14篇
  2019年   26篇
  2018年   20篇
  2017年   21篇
  2016年   18篇
  2015年   8篇
  2014年   29篇
  2013年   33篇
  2012年   39篇
  2011年   32篇
  2010年   40篇
  2009年   28篇
  2008年   21篇
  2007年   34篇
  2006年   29篇
  2005年   31篇
  2004年   28篇
  2003年   36篇
  2002年   17篇
  2001年   23篇
  2000年   22篇
  1999年   28篇
  1998年   37篇
  1997年   28篇
  1996年   30篇
  1995年   26篇
  1994年   22篇
  1993年   15篇
  1992年   23篇
  1991年   14篇
  1990年   15篇
  1989年   11篇
  1988年   17篇
  1987年   12篇
  1986年   14篇
  1985年   10篇
  1984年   7篇
  1983年   7篇
  1982年   4篇
  1981年   5篇
  1980年   3篇
  1979年   6篇
  1977年   4篇
  1976年   3篇
  1975年   2篇
  1974年   2篇
  1950年   1篇
排序方式: 共有929条查询结果,搜索用时 31 毫秒
71.
The Nottingham prognostic index (NPI) is a widely adopted prognostic tool in breast cancer. The HER-2 oncogene overexpression is also associated with higher risk. The aim of our study is to investigate the correlation between the NPI and HER-2 in breast cancer. Two hundred and five patients with breast cancer managed in the Department of Surgery, University of Hong Kong Medical Centre, at Queen Mary Hospital between January 1995 and December 1997 were studied. This is a retrospective analysis of prospectively collected database. Variables evaluated for the analysis of prognostic significance included tumor size, axillary lymph node status, histological grade, estrogen and progesterone receptor status and HER-2 oncogene expression. NPI was calculated from tumor size, lymph node status and histological grade. In univariate analysis, tumor size, axillary lymph node status, distant metastasis status, HER-2 oncogene overexpression and NPI score were found to be significant variables. Significant poorer overall survival was also observed with higher NPI category and positive HER-2. Only tumor size and NPI category with subdivision by HER-2 status were independent factors in multivariate analysis . The combination of the HER-2 oncogene expression status with the widely adopted NPI provides a reliable way to predict prognosis in breast cancer patients.  相似文献   
72.
To determine the cause of a positive direct antiglobulin test (DAT), blood banks routinely perform serologic tests on eluates prepared from DAT-positive red cells. Negative eluates traditionally have been suspected to be associated with drug reactions. This report confirms that the most frequent cause of a positive DAT and a nonreactive eluate is hypergammaglobulinemia. The results of 74 patient samples with positive DATs were analyzed retrospectively. Eluates prepared from the red cells of 54 patients (72.9%) reacted; eluates from 20 patients (27.1%) did not react. This latter group had identical serologic and clinical findings, suggesting that they made up a homogeneous group. In particular, the patients had a positive DAT, a negative indirect antiglobulin test, and a negative eluate; an increased serum concentration of IgG; and no evidence of hemolysis. In a subsequent study, DATs were performed prospectively on red cells from 44 consecutive patients with elevated serum IgG levels. The serum IgG concentration was highest in the three patients whose red cells had a positive DAT. The DAT also became positive in two patients treated with high-dose intravenous gammaglobulin (IV IgG). These studies indicate that a negative eluate from red cells with a positive DAT, a common serologic finding, is often caused by hypergammaglobulinemia. The authors postulate that IgG binds nonspecifically to the red cells because of the hypergammaglobulinemia.  相似文献   
73.
Adapting to psychosocial and physical changes can trigger nonspecific somatic complaints and depression. Somatization has been noted in all societies and cultures; however, it is more frequently observed in Asian populations. This study used the Geriatric Depression Scale (GDS) to screen 100 Taiwanese American older adults for depressive symptoms and found that seven participants (7%) experienced depressive symptoms (GDS >/= 14). Although the mean number of illnesses reported was significantly higher (t = -16.8, P <.001) in the depressive group, the seven individuals did not focus on physical symptoms during interview. They reported guilt, sadness, anger, resentment, loneliness, helplessness, hopelessness, inability to enjoy activities, and anhedonia. If older adults are given the time to express themselves, they are able to reveal their emotional pain and distress rather than remain preoccupied with somatic complaints. A simple depression screening tool, such as the GDS, can help detect depression.  相似文献   
74.
75.
目的:观察聚乙二醇法在组织工程瓣膜准备中的应用价值,比较聚乙二醇去细胞前后组织工程瓣膜的物理特性。方法:实验于2005-10/2006-03在华中科技大学同济医学院基础医学院生物化学系实验室完成。①实验分组:取猪10只,由于猪主动脉瓣为三叶瓣结构,共取得瓣叶组织30个,麻醉后宰杀取其心脏动脉瓣膜,分为去细胞组和对照组,每组各15个。②实验方法:去细胞组用聚乙二醇和DNase I处理;瓣叶组织放入1kg/L聚乙二醇,室温下浸泡30~45min,振荡器加以振荡;含抗生素磷酸盐缓冲液浸泡24h,反复3次洗脱;以5×104U/L DNase I液浸泡处理1h;对照组仅以含抗生素磷酸盐缓冲液浸泡24h,反复3次洗脱。③实验评估:苏木精-伊红染色、扫描电镜观察去细胞情况,吸光度(A)值,计算去细胞率(%)=(对照组A值-去细胞组A值)/对照组A值×100%。猪去细胞瓣膜条置于力学测试仪测定最大负荷、最大应力、最大应变和弹性模量。结果:纳入猪10只,均进入结果分析。①去细胞组织形态学观察:去细胞组猪瓣膜组织中看不到细胞成分,且细胞外基质结构保存完整,胶原纤维排列整齐,无明显断裂,仍呈波浪状平行排列,结构紧凑,弹性纤维结构清晰,组织无明显水肿。②DNA含量分析:聚乙二醇处理后去细胞百分率为95.32%。③生物力学检测:与对照组比较,去细胞组瓣膜组织最大负荷[(12.586±1.693),(10.242±1.435)N,P>0.05]、最大应力[(2.346±0.342),(1.877±0.572)N/mm,P>0.05]、弹性模量(15.152±1.579,14.549±0.678,P>0.05)、最大应变[(31.685±7.533),(28.118±6.045)mm/N,>0.05]等均无显著差异。P结论:聚乙二醇法去除细胞完全,细胞外基质保存完整,对组织机械性能无明显影响,适于构建组织工程瓣膜。  相似文献   
76.
77.
Chen D  Zhang Y  Shen H  Wei Y  Huang D  Tan Q  Lan X  Li Q  Chen Z  Li Z  Ou L  Suen H  Ding X  Luo X  Li X  Zhan X 《Parasitology research》2011,109(2):305-314
The study was to understand the Angiostrongylus cantonensis infectious situation of rodent definitive host, snail intermediate host, and local residents in the west-central region of Guangdong Province in China. The snails Achatina fulica and Pomacea canaliculata collected from the survey place were digested with artificial gastric juice, and the third-stage larvae of A. cantonensis in the snails were examined under microscope. The heart and lung of rats captured from the survey place were taken to check the adult of A. cantonensis. The questionnaire surveys related to the infection of A. cantonensis were taken in local residents randomly selected, and the IgG antibody against A. cantonensis was tested in those residents with enzyme-linked immunosorbent assay (ELISA). A total of 1,391 rats including eight kinds of rats, such as Rattus norvegicus, Rattus flavipectus, Bandicota indica, Rattus sladeni, Mus musculus, Rattus rattoides, Suncus Murinus, and Rattus confucianus, were examined and 132 of them were infected by A. cantonensis, with an average infection rate of 9.49% and a mean intensity of A. cantonensis in infected rats was 9.39. A total of 3,184 snails A. fulica and 3,723 snails P. canaliculata were detected. The average infection rates of them were 25.03% (797/3,184) and 6.50% (242/3,723), respectively. There were 180 positive samples of IgG antibody against A. cantonensis in 1,800 serum samples of the residents, with a positive rate of 10.00%. The west-central region of Guangdong Province is the natural focus of A. cantonensis. In comparison with the investigation results in other regions of China, the infection rate of rat definitive host is at the middle level; in the intermediate host, the infection rate of snail A. fulica is above the middle level, and the infection rate of snail Pomacea canaliculata is below the middle level. Some local residents had already been infected by A. cantonensis or at the risk of being infected.  相似文献   
78.
79.
Interocclusal discrepancies can be eliminated by a clinical remount procedure, but most practitioners avoid it because of the time involved. This article introduces a new timesaving method, the modified split‐cast technique. It uses a semi‐adjustable articulator, tin foil as plaster separator, and an addition‐type, silicone bite‐registration material. The technician does most of the remounting procedures before the denture delivery appointment, so the dentist spends very little time chairside to complete the clinical remount procedure. Compared with the conventional and two other remounting techniques, the new technique is faster and easier to manipulate.  相似文献   
80.
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