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   294篇
  免费   75篇
耳鼻咽喉   2篇
妇产科学   7篇
基础医学   168篇
临床医学   7篇
内科学   44篇
皮肤病学   5篇
神经病学   9篇
特种医学   2篇
外科学   11篇
综合类   1篇
一般理论   1篇
预防医学   8篇
药学   1篇
肿瘤学   103篇
  2021年   1篇
  2020年   1篇
  2016年   3篇
  2015年   3篇
  2014年   3篇
  2013年   5篇
  2012年   5篇
  2011年   6篇
  2010年   10篇
  2009年   4篇
  2008年   7篇
  2007年   8篇
  2006年   12篇
  2005年   14篇
  2004年   11篇
  2003年   17篇
  2002年   20篇
  2001年   16篇
  2000年   23篇
  1999年   13篇
  1998年   13篇
  1997年   10篇
  1996年   9篇
  1995年   11篇
  1994年   7篇
  1993年   6篇
  1992年   16篇
  1991年   5篇
  1990年   10篇
  1989年   9篇
  1988年   17篇
  1987年   13篇
  1986年   16篇
  1985年   11篇
  1984年   5篇
  1983年   8篇
  1982年   4篇
  1979年   1篇
  1978年   2篇
  1977年   1篇
  1975年   3篇
  1974年   3篇
  1973年   1篇
  1969年   1篇
  1968年   1篇
  1967年   1篇
  1966年   3篇
排序方式: 共有369条查询结果,搜索用时 828 毫秒
41.
OBJECTIVE: To investigate the presence of angiogenic factors in benign, premalignant and malignant vulvar lesions. STUDY DESIGN: Immunohistochemical demonstration of vascular endothelial growth factor (VEGF) and platelet-derived endothelial cell growth factor (PD-ECGF) in normal vulvar skin, lichen sclerosus, vulvar intraepithelial neoplasia (VIN) and vulvar cancer. RESULTS: VEGF was found in the majority of vulvar cancers but only a minority of VIN lesions. PD-ECGF was found in the majority of lesions. CONCLUSION: Demonstration of angiogenesis may suggest which preinvasive lesions will progress to invasive cancer.  相似文献   
42.
The present paper describes a new monoclonal antibody (KB61) raised against hairy cell leukaemia cells. Antibody KB61 recognizes a molecule of approximately 40,000 molecular weight on human B cells. It reacts with B lymphocytes in the peripheral blood, in primary lymphoid follicles, in the mantle zone of secondary follicles, in interfollicular areas and in splenic marginal zone areas. However, germinal centre lymphoid cells do not express the antigen recognized by antibody KB61. The antibody shows limited reactivity outside the lymphoid system, i.e. polymorphs, tissue macrophages endothelial cells in the hepatic sinusoids. Antibody KB61 discriminates between different types of B-cell malignancies, reacting with the neoplastic cells in hairy cell leukaemia, chronic lymphocytic leukaemia (of B-cell type), prolymphocytic leukaemia and centrocytic lymphoma, but not with acute lymphoblastic leukaemia, germinal centre-derived lymphomas (other than centrocytic), Burkitt's lymphoma and lymphoblastic lymphoma. Antibody KB61 may be of value in the study of B-cell subpopulations and in the differential diagnosis of B-cell neoplasms.  相似文献   
43.
The monoclonal antibody CAM 5.2 was used to investigate the expression of lower molecular weight cytokeratin proteins immunocytochemically in conventionally processed samples of schistosoma-associated squamous metaplasias and carcinomas of the urinary bladder. The antibody did not differentiate between squamous metaplasias and well differentiated squamous carcinomas, though it did focally label moderate to poorly differentiated tumours. The results suggest that squamous carcinomas of the bladder in this setting differ fundamentally from such tumours at other sites in their patterns of cytokeratin protein expression.  相似文献   
44.
Interleukin 4 receptor expression on human lung tumors and normal lung.   总被引:1,自引:0,他引:1  
Interleukin 4 (IL-4) receptors were detected by a monoclonal antibody on tumor cells of 10 of 29 squamous cell carcinomas and 6 of 17 adenocarcinomas of the lung. None of the small cell carcinomas or carcinoid tumors stained. Parallel sections stained for epidermal growth factor receptors showed that all but 2 of the IL-4 receptor-positive tumors also expressed epidermal growth factor receptors. Positive labeling for IL-4 receptors was also obtained on nonneoplastic bronchial epithelium and on lymphocytes and macrophages infiltrating the tumor stroma. The role of IL-4 and its receptor in normal human lung is unknown, but the expression of IL-4 receptors on particular subtypes of lung tumors suggests that they may have a role in differentiation or proliferation of squamous and adenocarcinomas.  相似文献   
45.
BACKGROUND: Vascular endothelial cell growth factor (VEGF) acts by phosphorylating specific tyrosine kinase receptors on endothelial cell membrane promoting angiogenesis. The study of the activation status of VEGF receptors in human malignancies has recently become feasible by means of specific monoclonal antibodies recognising the phosphorylated form of these receptors. MATERIALS AND METHODS: In the current study, we investigate the expression of the phosphorylated VEGFR2/KDR receptor in normal colon and colorectal adenocarcinomas in parallel with histopathological parameters, prognosis and the expression of the 'hypoxia inducible factor' HIF1alpha. RESULTS: pVEGFR2/KDR was weakly expressed in the normal colon, but it was expressed strongly in the cytoplasm and nuclei of cancer cells and in the tumour associated vasculature, mainly at the invading tumour edge. pVEGFR2/KDR expression in cancer cells was significantly associated with a tumour diameter > 6 cm (P = 0.04), poor histological differentiation (P = 0.004) and with high CEF1alpha expression (P = 0.05). High pVEGFR2/KDR expressing vascular density was significantly related with a high VEGF and HIF1alpha expression in cancer cells (P = 0.02 and 0.03, respectively). This was also related significantly to high pVEGFR2/KDR expression in cancer cells. In multivariate analysis, the most significant predictors for death were lympho-vascular invasion (P < 0.001) followed by VEGF (P = 0.014), node status (P = 0.015), standard vascular density (P = 0.022) and necrosis (P = 0.032). CONCLUSIONS: pVEGFR2 receptors are largely expressed in colon cancer cells and intratumoural vasculature. As VEGF targeting agents enter the clinical practice, the role of monoclonal antibodies recognising the phosphorylated form of VEGF receptors as predictors of response to targeted therapies should be sought in clinicopathological trials.  相似文献   
46.
47.
48.
Carbonic anhydrase-9 (CA9), a transmembrane enzyme with an extracellular active site, is involved in the reversible metabolism of the carbon dioxide to carbonic acid. Up-regulation of CA by hypoxia and the hypoxia-inducible factor (HIF) pathway has been recently postulated (Wykoff et al. Cancer Res., 60: 7075-7083, 2000). In the present study we examined the expression of this enzyme in non-small cell lung cancer. Of 107 cases analyzed, 39 (36.4%) had strong membrane/cytoplasmic expression of CA9 and were grouped as positive. The staining was confined around areas of necrosis, and a significant association of CA9 expression with the extent of necrosis was noted (P = 0.004). Nevertheless, 38 of 74 cases with focal or extensive necrosis did not express CA9. CA9 expression was more frequent in the squamous cell histology (P = 0.001) and with advanced T stage (P = 0.009). A significant coexpression of CA9 with platelet-derived endothelial cell growth factor and basic fibroblast growth factor receptor expression was noted. Double staining of CA9 with anti-CD31 monoclonal antibody revealed an overall higher microvessel density in the areas expressing CA9 than in negative areas (P = 0.0005). Thirty-one of 38 CA9-positive cases were positive for HIF1a/HIF2a, but HIF positivity was a more common event (68 of 107) and their patterns of expression were diffuse (not confined in the necrotic areas). A direct association of CA9 expression with epidermal growth factor receptor, c-erbB-2, and MUC1 expression was also noted (P < 0.04). Survival analysis showed that CA9 expression is related to poor prognosis. CA9 expression in tumors with low vascularization defined a prognosis similar to the one of patients with highly angiogenic tumors. Multivariate analysis revealed that CA9 expression is a significant prognostic factor independent of angiogenesis. We conclude that CA9 is an important molecule in non-small cell lung cancer, the up-regulation of which occurs in highly hypoxic/necrotic regions of the tumors. The expression of CA9 is linked to the expression of a constellation of proteins involved in angiogenesis, apoptosis inhibition, and cell-cell adhesion disruption, which explains the strong association of CA9 with poor outcome.  相似文献   
49.
50.
The efficacy of cyclobenzaprine (Flexeril), as compared with placebo, was tested in a 12-week, double-blind, controlled trial of 120 patients with fibrositis. Of the patients who received placebo, 52% dropped out due to lack of efficacy of the drug, compared with 16% of patients taking cyclobenzaprine. The dropout rate due to adverse reactions was similar in the 2 groups. Patients taking cyclobenzaprine experienced a significant decrease in the severity of pain and a significant increase in the quality of sleep. There was a trend toward improvement in the symptoms of fatigue, but morning stiffness was not alleviated. These improvements in symptoms were associated with a significant reduction in the total number of tender points and in muscle tightness. Our findings indicate that cyclobenzaprine is a useful adjunct in treating patients with the fibrositis syndrome.  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