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   414篇
  免费   37篇
  国内免费   8篇
耳鼻咽喉   6篇
儿科学   15篇
妇产科学   8篇
基础医学   53篇
口腔科学   9篇
临床医学   42篇
内科学   80篇
皮肤病学   63篇
神经病学   38篇
特种医学   6篇
外科学   28篇
综合类   6篇
预防医学   36篇
眼科学   15篇
药学   28篇
中国医学   1篇
肿瘤学   25篇
  2024年   4篇
  2023年   14篇
  2022年   16篇
  2021年   29篇
  2020年   23篇
  2019年   21篇
  2018年   30篇
  2017年   17篇
  2016年   26篇
  2015年   24篇
  2014年   32篇
  2013年   28篇
  2012年   36篇
  2011年   44篇
  2010年   28篇
  2009年   12篇
  2008年   5篇
  2007年   13篇
  2006年   6篇
  2005年   3篇
  2004年   6篇
  2003年   6篇
  2002年   6篇
  2001年   3篇
  2000年   2篇
  1999年   2篇
  1998年   1篇
  1997年   3篇
  1996年   3篇
  1995年   2篇
  1993年   1篇
  1992年   1篇
  1990年   5篇
  1981年   2篇
  1979年   1篇
  1977年   1篇
  1975年   1篇
  1974年   1篇
  1973年   1篇
排序方式: 共有459条查询结果,搜索用时 0 毫秒
451.
Overexpression of tissue inhibitor of metalloproteinase-1 at either the messenger RNA or protein level has been related to a poorer prognosis in breast cancer. We investigated the role of tissue inhibitor of metalloproteinase-1 tissue expression, which was evaluated by immunohistochemistry staining of paraffin-embedded samples, as a possible prognostic indicator in breast cancer. The study included 266 patients treated by primary surgery. Tumors were scored tissue inhibitor of metalloproteinase-1 positive when at least 10% of the cells showed moderate or strong staining. Staining was observed in 76 (28.6%) patients; by multivariate analysis, factors independently associated with tissue inhibitor of metalloproteinase-1 positivity included more than 9 metastatic axillary nodes, high Mib-1 expression, and positivity for plasminogen activator inhibitor and CD44. With a median follow-up of 125 months, tissue inhibitor of metalloproteinase-1 expression showed a significant prognostic role in disease-free and overall survival by univariate analysis. Multivariate analysis confirmed an independent negative prognostic impact of tissue inhibitor of metalloproteinase-1 on overall but not disease-free together with high values of Mib-1. The number of involved axillary nodes, and triple negativity were independent predictors of either poorer disease-free or overall survival. In our study, tissue inhibitor of metalloproteinase-1 expression was significantly related to markers of tumor aggressiveness and was a powerful indicator of poorer prognosis, with a difference in 10-year disease-free and overall survival of 14% and 28%, respectively, between tissue inhibitor of metalloproteinase-1-negative and tissue inhibitor of metalloproteinase-1-positive cases. Expression of tissue inhibitor of metalloproteinase-1 also was an independent prognostic factor in node-positive cases, indicating a possible role of tissue inhibitor of metalloproteinase-1 as a marker of reduced chemosensitivity. Thus, tissue inhibitor of metalloproteinase-1 may have a role in clinical practice as a prognostic and predictive factor and a possible target for future therapies.  相似文献   
452.
IntroductionIntracardiac thrombi (ICT), more commonly encountered at autopsy, are well documented with underlying cardiovascular disease. Occurrence of ICT in systemic diseases without an intrinsic cardiac disorder is rare. The aim of this autopsy study was to highlight such an occurrence.MethodsFrom 1996 to 2010, cases with ICT unrelated to primary cardiac disorders were selected at autopsy and analyzed. Clinical and investigational data were obtained from the medical records. The location, morphology, size, and histological appearance of the thrombi were noted. The thrombi were then classified on the basis of their location, nature, and histology (fresh and/or organized); this was correlated with the clinical setting.ResultsAmong a total of 11,724 autopsies performed in 15 years, 276 patients (2.4%) had ICT. Of these, 45 patients (0.4%) had ICT that were unrelated to primary cardiac diseases. There were 25 men and 20 women with a mean age of 46.1 years. Antemortem diagnosis was not made in any of these patients. Eight patients each (35.6%) showed isolated left-sided and multichambered involvement, while the rest of the hearts (64.4%) had thrombi in the right-sided chamber(s). The recognizable risk factors were underlying cancers (24.4%), prolonged immobilization (20%), systemic lupus erythematosus (6.7%), pregnancy (4.4%), nephropathy (4.4%), primary antiphospholipid antibody syndrome (2.2%), and ulcerative colitis (2.2%). However, 16 patients (35.7%) had no obvious predisposing factor, although investigations for prothrombotic markers had not been done. Diabetes mellitus, chronic alcoholism, and deep vein thrombosis of the lower limbs had been clinically documented in some of them. The cause of death in most patients (73.3%) had been related to pulmonary and/or systemic thromboembolism.ConclusionsThis autopsy study emphasizes the great need for a higher index of suspicion of in situ thrombosis in the heart in hypercoagulable states so as to curtail the morbidity and mortality of the primary disease process.  相似文献   
453.
[目的]3-羟基-3-甲基戊二酰辅酶A还原酶(3-hydroxy-3-methylglutaryl coenzyme A reductase,HMGR)和1-去氧-D-木酮糖-5-磷酸还原异构酶(1-deoxy-D-xylulose-5-phosphate reductoisomerase,DXR)是萜类生物合成途径的...  相似文献   
454.
455.
The accumulation of advanced glycation endproducts (AGE) due to non-enzymic glycation of proteins has been implicated in several pathophysiologies associated with ageing and diabetes. The formation of AGE is accelerated in hyperglycaemic conditions, which alter the structure and function of long-lived proteins. Thus inhibition of the formation of AGE is believed to play a role in the prevention of diabetic complications. In the present study we evaluated the antiglycating effect of aqueous extracts of various plant-based foods. The effect of aqueous extracts of these agents in terms of their ability to prevent the accumulation of AGE due to fructose-mediated in vitro glycation of eye lens soluble proteins was investigated. The degree of protein glycation in the absence and presence of dietary extracts was assessed by different complementary methods, i.e. non-tryptophan AGE fluorescence, AGE-induced cross-linking by SDS-PAGE and glyco-oxidative damage by carbonyl assay. Five out of the seventeen agents tested showed significant inhibitory potential against in vitro protein glycation in a dose-dependent manner. Prominent among them were ginger, cumin, cinnamon, black pepper and green tea, which inhibited in vitro AGE formation to lens proteins 40-90 % at 1.0 mg/ml concentration. Assessing their potential to reduce the amount of glycated protein using boronate affinity chromatography and also their ability to prevent the formation of specific antigenic-AGE structures by immunodetection further substantiated the importance of ginger, cumin and cinnamon in reducing AGE burden. These findings indicate the potential of some dietary components to prevent and/or inhibit protein glycation. Thus these dietary agents may be able to be exploited for controlling AGE-mediated diabetic pathological conditions in vivo.  相似文献   
456.
The incidence of breast cancer is increasing worldwide. In this review article, the authors compare and contrast the incidence of breast cancer, and the inherent differences in the United States (US) and India in screening techniques used for diagnosing breast cancer. In spite of these differences, core biopsies of the breast are common for diagnosis of breast cancer in both countries. The authors describe "Best Practices" in the reporting and processing of core biopsies and in the analysis of estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor Receptor 2 (Her2/neu). The pitfalls in the diagnosis of fibroepithelial lesions of the breast on core biopsy are discussed, as also the significance of pseudoangiomatous stromal hyperplasia of the breast (PASH) is discussed in core biopsy. In this review, the management and diagnosis of flat epithelial atypia and radiation atypia are elaborated and the use of immunohistochemistry (IHC) in papillary lesions, phyllodes tumor, and complex sclerosing lesions (radial scars) is illustrated. Rarer lesions such as mucinous and histiocytoid carcinoma are also discussed.  相似文献   
457.
458.
Invasive micropapillary carcinoma is a rare variant of invasive ductal carcinoma of the breast. This variant has been described as clinically aggressive due to its high frequency of lymphovascular invasion, axillary nodal metastases, and a greater degree of loco-regional recurrence. Invasive micropapillary carcinoma can have a variety of imaging presentations, typically presenting as an irregular mass. This case report describes a unique presentation of invasive micropapillary carcinoma and illustrates the propensity of invasive micropapillary carcinoma to secrete fluid and have a lack of regional lymphadenopathy. The challenges of the accompanying diagnostic imaging-work up are discussed.  相似文献   
459.
The postoperative mammographic imaging appearance related to lymphovenous bypass and vascularized lymph node transfer has not been described. It is important for breast imagers to become familiar with the expected appearance of surgical changes that can be seen in the follow up imaging of breast cancer survivors in order to create accurate reports and adjust imaging protocols to improve imaging quality and lessen patient discomfort as needed.  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