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   1087篇
  免费   115篇
  国内免费   2篇
耳鼻咽喉   19篇
儿科学   18篇
妇产科学   97篇
基础医学   114篇
口腔科学   11篇
临床医学   153篇
内科学   272篇
皮肤病学   4篇
神经病学   88篇
特种医学   35篇
外科学   88篇
综合类   29篇
预防医学   96篇
眼科学   2篇
药学   65篇
中国医学   2篇
肿瘤学   111篇
  2022年   11篇
  2021年   8篇
  2020年   15篇
  2019年   15篇
  2018年   20篇
  2017年   19篇
  2016年   16篇
  2015年   25篇
  2014年   24篇
  2013年   39篇
  2012年   34篇
  2011年   41篇
  2010年   18篇
  2009年   29篇
  2008年   64篇
  2007年   46篇
  2006年   54篇
  2005年   61篇
  2004年   45篇
  2003年   32篇
  2002年   48篇
  2001年   24篇
  2000年   40篇
  1999年   35篇
  1998年   18篇
  1997年   9篇
  1996年   21篇
  1995年   15篇
  1994年   16篇
  1993年   17篇
  1992年   19篇
  1991年   25篇
  1990年   22篇
  1989年   22篇
  1988年   22篇
  1987年   19篇
  1986年   16篇
  1985年   23篇
  1984年   10篇
  1983年   14篇
  1982年   13篇
  1981年   16篇
  1980年   11篇
  1979年   27篇
  1978年   10篇
  1977年   12篇
  1976年   7篇
  1975年   7篇
  1971年   6篇
  1969年   7篇
排序方式: 共有1204条查询结果,搜索用时 15 毫秒
1.
OBJECTIVE: To examine the relationship between growth rate of vestibular schwannomas and the expression of various growth factor receptors. STUDY DESIGN: Retrospective case review of clinical growth rate in conjunction with a histopathologic and immunohistochemical reexamination of archival specimens. SETTING: A tertiary referral neurotologic center. PATIENTS: Three groups: a historical group to act as controls, consisting of 30 patients with sporadic vestibular schwannomas removed before the unit adopted an initial interval scan policy; a group of 14 patients with sporadic vestibular schwannomas who had undergone an initial interval scan policy, showed radiologic evidence of growth, and therefore had their schwannoma removed; and a group of 16 schwannomas removed from 11 neurofibromatosis Type 2 patients. MAIN OUTCOME MEASURES: A comparison between the three clinical groups using immunohistochemical studies to determine the level of expression of the proliferation factor Ki-67, c-erbB-2, and c-erbB-3 receptors and fibroblastic growth factor receptors 1 and 4. RESULTS: The level of expression of the proliferation factor Ki-67 was very low and similar in all three groups. C-erbB-2 and c-erbB-3 receptors were not expressed in any of the groups. fibroblastic growth factor receptor 4 expression was not significantly different, but there was a variation in the expression of fibroblastic growth factor receptor 1 between the three groups that correlated well with the differing incidence of growth in the groups. The increase in expression of fibroblastic growth factor receptor 1 in the neurofibromatosis Type 2 group was not statistically significant, but the increase in expression of fibroblastic growth factor receptor 1 in the growing sporadic group was statistically significant when compared with the historical controls. The level of fibroblastic growth factor receptor 1 expression correlates significantly with the rate of growth as measured on interval magnetic resonance imaging. CONCLUSIONS: Overexpression of fibroblastic growth factor receptor 1 has a positive correlation with the incidence and the rate of growth of sporadic vestibular schwannomas.  相似文献   
2.
3.
4.
Summary This paper reports the 8-year results of comparing the use of two types of adjuvant chemotherapy following involved field radiotherapy for clinical stages I and II high-grade non-Hodgkin's lymphoma. Twenty-four patients received 6 weeks of VAP plus 2 years of oral maintenance chemotherapy, and 30 had six cycles of CMOPP. Four patients were not in complete remission at completion of i. v. chemotherapy (CR rate 91%). Ten patients (18.5%) have relapsed (VAP/M=5; CMOPP=5), with only two of these remaining alive, both of them being disease free. There have been three deaths from intercurrent causes, one from malignant melanoma and the other two from myocardial infarction. The relapse-free survivals at 2, 5 and 8 years were 80%, 76% & 76% respectively. The overall survivals at the same time points were 86%, 72% & 68%. There were no significant differences in either relapse-free or overall survival for either of the two treatment groups. The shorter period of weekly intravenous chemotherapy (VAP/M) was better tolerated than 36 weeks of CMOPP, and the former appears to produce equivalent results.  相似文献   
5.
One hundred sixty-two patients with Stages III and IV non-Hodgkin's lymphoma of low-grade histologic type were treated with combination chemotherapy using cyclophosphamide, vincristine, and prednisolone (CVP) followed by radiotherapy to sites of previous bulk disease. The patients were randomized to receive either follow-up alone or "maintenance" chemotherapy with 2 years of intermittent chlorambucil. A complete remission was obtained in 56% of patients and the median survival was 64 months (median follow-up, 74 months). Multivariate analysis revealed stage (P less than 0.0001) and Karnofsky performance status (P = 0.021) to predict complete response (CR) and the achievement of a CR (P less than 0.0001), female sex (P = 0.008), the absence of bulk disease (P = 0.038) and low serum alkaline phosphatase (P = 0.002) to predict prolonged survival. The median relapse-free survival (RFS) of the complete responders was 41 months. A prolonged RFS was predicted by low stage (P = 0.014), low serum lactic dehydrogenase (LDH) (P = 0.045) levels, and by the administration of maintenance chlorambucil (P = 0.045). A prolonged survival of the complete responders was predicted by a low number of nodal sites of involvement with lymphoma at presentation (P = 0.022) and lack of liver involvement (P = 0.011). The administration of oral maintenance therapy with chlorambucil for a full 2 years was only possible in 38% of patients, mainly because of progression of disease and the induction of thrombocytopaenia, but despite this it prolonged the median RFS by 38 months and its use could be considered when future studies are being designed.  相似文献   
6.
Variation has been observed in the structural polypeptides of swine vesicular disease viruses isolated from the United Kingdom and Hong Kong. Despite the limited number of isolates examined, several distinct polypeptide patterns were obtained when the virus structural proteins were examined by polyacrylamide gel electrophoresis. Isolates from outbreaks in the United Kingdom which were known to be connected gave the same polypeptide pattern, whereas viruses with different polypeptide patterns could not be traced to a common source. The different polypeptide patterns were obtained consistently and were not altered by passage of the virus in tissue culture. In general, isolates with identical polypeptide patterns could not be distinguished by neutralization or antibody blocking tests or by competition radioimmunoassays. However, isolates with different polypeptide patterns could be differentiated by antibody blocking tests or radioimmunoassay. The correlation between the serological tests and the polyacrylamide gel electrophoresis analyses illustrates the value of analyzing structural polypeptides in the epidemiological study of swine vesicular disease.  相似文献   
7.
个体化下肢小腿假肢接受腔设计的生物力学评价技术研究   总被引:3,自引:0,他引:3  
作为传递体重、固定假肢的部件 ,接受腔对于小腿假肢使用的舒适性和方便程度有决定性的作用。本研究建立了基于有限元应力分析的小腿假肢生物力学评价技术平台 ,实现了小腿残端 /接受腔 3D几何建模与信息交互、三维有限元自动建模及应力分析。 3D模型与信息交互的实现基于得到广泛支持的OpenGL技术 ,有限元模型的构建采用了专门针对小腿残端 /接受腔结构特点的自动建模方法 ,通过构建档案数据库系统作为整个系统的操作平台。该技术平台可与现有的CAD/CAM系统相结合 ,为接受腔的个体化设计提供生物力学定量化依据。其临床应用将改善传统的设计流程 ,提高设计效率。同时 ,它也是未来构建接受腔设计专家 /智能系统的基础。  相似文献   
8.
9.
The use of pig blood samples dried on paper discs for the detection of antibodies against FMDV by the liquid phase blocking ELISA has been evaluated. The average volume of whole heparinised blood required to fully saturate 6.0 mm discs was 7.65 microliters (range 7.2 to 8.1; variation = 0.24, P = 0.05). When 200 clinically healthy animals were assessed by virus neutralisation (VN) titres up to 1/22 were recorded against types O, A and C, 97% being 1/11 or less. Using ELISA, results were more skewed. Overall, 91% showed titres of 1/32 or less, and there were occasional high non-specific reactors with types O and A. Using small groups of sera from experimental animals, a VN titre of 1/16 was found to be equivalent to an ELISA titre of approximately 1/100 (log10 2.0 +/- 0.2) with type O and 1/56 (log10 1.75 +/- 0.1) for type A. Although some loss in sensitivity from disc dried sera was found in selected negatives on testing at a single dilution of 1/32, sera from vaccinated animals with VN titres of 1/16 to 1/708 all gave strong positive results. A monoclonal antibody (Mab) assay was successfully developed to detect different swine anti-FMDV antibody isotypes.  相似文献   
10.
Lung carcinoma remains one of the most frequent and aggressive human neoplasms. Fortunately, in the last decades, the increasing knowledge of the molecular mechanisms leading to cancer development has allowed the use of targeted therapies with improvement of prognosis in many patients. Clinical management has also changed after the introduction of endobronchialultrasonographic bronchoscopy that allows a conservative staging of lung tumors, avoiding the need of mediastinoscopy for lymph node staging. Lung pathologists and cytopathologists are facing the challenge of giving the more comprehensive prognostic and predictive information with ever smaller tissue or cytological samples. The aim of this review is to summarize the molecular testing for non-small cell lung carcinoma and how pathologists can contribute to the patient's outcome with a conscious management of biological samples.  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