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   468篇
  免费   49篇
  国内免费   3篇
耳鼻咽喉   1篇
儿科学   44篇
妇产科学   1篇
基础医学   50篇
口腔科学   13篇
临床医学   30篇
内科学   112篇
皮肤病学   5篇
神经病学   10篇
特种医学   55篇
外科学   26篇
综合类   8篇
预防医学   21篇
眼科学   59篇
药学   59篇
肿瘤学   26篇
  2022年   3篇
  2021年   3篇
  2020年   2篇
  2019年   4篇
  2018年   9篇
  2017年   12篇
  2016年   9篇
  2015年   16篇
  2014年   22篇
  2013年   14篇
  2012年   11篇
  2011年   14篇
  2010年   16篇
  2009年   25篇
  2008年   19篇
  2007年   14篇
  2006年   21篇
  2005年   13篇
  2004年   12篇
  2003年   9篇
  2002年   9篇
  2001年   17篇
  2000年   10篇
  1999年   11篇
  1998年   21篇
  1997年   29篇
  1996年   27篇
  1995年   15篇
  1994年   26篇
  1993年   14篇
  1992年   8篇
  1991年   8篇
  1990年   5篇
  1989年   9篇
  1988年   8篇
  1987年   5篇
  1986年   5篇
  1985年   5篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1981年   5篇
  1980年   6篇
  1976年   5篇
  1974年   2篇
  1973年   1篇
  1972年   6篇
  1970年   1篇
  1969年   1篇
  1968年   2篇
排序方式: 共有520条查询结果,搜索用时 25 毫秒
131.
132.
BACKGROUND: Despite the availability of antitoxin and antibiotics, the mortality rate for diphtheria remains high, mostly because of cardiac complications. METHODS: During 1 year, 154 Vietnamese children with diphtheria admitted to a referral hospital were studied prospectively with clinical examination, including a simple pseudomembrane score, 12-lead and 24-hour electrocardiography, measurement of serum cardiac enzyme levels, and estimation of troponin T levels. RESULTS: Thirteen children had diphtheritic cardiomyopathy on admission, and 19 developed it subsequently. Twelve children (8%) died. The combination of pseudomembrane score of >2 and bull neck predicted the development of diphtheritic cardiomyopathy, with a positive predictive value of 83% and a negative predictive value of 93%. Administration of 24-hour electrocardiography on admission improved the ability to predict diphtheritic cardiomyopathy by 57%. Fatal outcome was best predicted by the combination of myocarditis on admission and a pseudomembrane score of >2. Of the cardiac enzyme levels measured, an elevated aspartate aminotransferase level was the best predictor. The presence of troponin T identified additional children with subclinical cardiac damage. CONCLUSIONS: The development of diphtheritic cardiomyopathy can be predicted by means of simple measures.  相似文献   
133.
本指南在美国胃肠病学学院及其实践资料委员会支持下制定。  相似文献   
134.
The survival of patients with Hodgkin's disease has dramatically improved over the past 30 years because of advances in treatment. However, concern for the risk of long-term complications has resulted in a number of trials to evaluate reduction of therapy. The consequences of these trials on recurrence, development of long-term complications, and survival remain unknown. One major consequence of successful treatment of Hodgkin's disease is the development of second malignant neoplasms. We sought to determine the factors most important for development of second tumors in pathologically staged and treated Hodgkin's disease patients followed for long intervals to provide background information for future clinical trials and guidelines for routine patient follow-up. Between April 1969 and December 1988, 794 patients with laparotomy staged (PS) IA-IIIB Hodgkin's disease were treated with radiation therapy (RT) alone or combined radiation therapy and chemotherapy (CT). There were 8,500 person-years of follow-up (average of 10.7 person-years per patient). Age and gender-specific incidence rates were multiplied by corresponding person-years of observation to obtain expected numbers of events. Observed to expected results were calculated by type of treatment, age at treatment, sex, and time after Hodgkin's disease. Absolute (excess) risk was expressed as number of excess cases per 10,000 person-years. Seventy-two patients have developed a second malignant neoplasm. Eight patients developed acute leukemia, 10 had non-Hodgkin's lymphoma (NHL), and 53 patients developed solid tumors at a median time of 5 years, 7.25 years, and 12.2 years, respectively, after Hodgkin's disease. One patient developed multiple myeloma 16.5 years after Hodgkin's disease. The relative risk (RR) of developing a second malignancy was 5.6. The absolute excess risk per 10,000 person-years (AR) of developing a second malignancy was 69.6 (7.0% excess risk per person per decade of follow-up). The highest RR occurred for the development of leukemia (RR = 66.2), however because of the low expected risk, the AR was only 9.3. The RR of solid tumors after Hodgkin's disease was lower (4.7); however, the AR was greater (49) than for acute leukemia. Among the solid tumors, breast, gastrointestinal, lung, and soft tissue cancers had the highest absolute excess risks. The risk for developing breast cancer after Hodgkin's disease was greatest in women who were under the age of 25 at treatment. The most significant risk factor for the development of both leukemia and solid tumors was the combined use of radiation therapy and chemotherapy. The RR following RT alone was 4.1 (AR = 51.1); for RT + CT (initially or at relapse) the RR was 9.75 (P < 0.05, nonoverlapping confidence limits, AR = 123.9). Survival following development of a second malignancy was poor in patients with leukemia, gastrointestinal tumors, lung cancer, and sarcoma. Survival from other malignancies including NHL and breast cancer was more encouraging. Second malignant neoplasms are a major cause of late morbidity and mortality following treatment for Hodgkin's disease. The most significant risk factor for the development of second tumors is the extent of treatment for Hodgkin's disease. Recommendations are presented for both prevention and early detection of these tumors.  相似文献   
135.
No method with low morbidity presently exists for obtaining serial hepatic gene expression measurements in humans. While hepatic fine needle aspiration (FNA) has lower morbidity than core needle biopsy, applicability is limited due to blood contamination, which confounds quantification of gene expression changes. The aim of this study was to validate FNA for assessment of hepatic gene expression. Liver needle biopsies and FNA procedures were simultaneously performed on 17 patients with chronic hepatitis C virus infection with an additional FNA procedure 1 week later. Nine patients had mild/moderate fibrosis and eight advanced fibrosis. Gene expression profiling was performed using Affymetrix microarrays and TaqMan qPCR; pathway analysis was performed using Ingenuity. We developed a novel strategy that applies liver‐enriched normalization genes to determine the percentage of liver in the FNA sample, which enables accurate gene expression measurements overcoming biases derived from blood contamination. We obtained almost identical gene expression results (ρ = 0.99, < 0.0001) comparing needle biopsy and FNA samples for 21 preselected genes. Gene expression results were also validated in dogs. These data suggest that liver FNA is a reliable method for serial hepatic tissue sampling with potential utility for a variety of preclinical and clinical applications.  相似文献   
136.
137.
138.
139.
Multiple myeloma: circulating lymphocytes that express plasma cell antigens   总被引:8,自引:0,他引:8  
The bone marrow and peripheral blood of 14 patients with multiple myeloma were studied with murine monoclonal antibodies that identify antigens on plasma cells (R1-3 and OKT10). Peripheral blood lymphocytes expressing plasma cell antigens were found in six cases. Five of these cases expressed the same antigens that were present on the plasma cells in the bone marrow. Patients that showed such peripheral blood involvement were found to have a larger tumor burden and higher bone marrow plasma cell proliferative activity. In some patients, antigens normally found at earlier stages of B cell differentiation (B1, B2, and J5) were expressed by peripheral blood lymphocytes and/or bone marrow plasma cells.  相似文献   
140.
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