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   193篇
  免费   16篇
耳鼻咽喉   6篇
儿科学   4篇
妇产科学   5篇
基础医学   23篇
口腔科学   10篇
临床医学   35篇
内科学   53篇
皮肤病学   2篇
神经病学   9篇
特种医学   6篇
外科学   16篇
综合类   3篇
预防医学   16篇
药学   14篇
肿瘤学   7篇
  2024年   1篇
  2023年   2篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   2篇
  2017年   6篇
  2016年   3篇
  2015年   5篇
  2014年   7篇
  2013年   11篇
  2012年   10篇
  2011年   10篇
  2010年   5篇
  2009年   13篇
  2008年   10篇
  2007年   10篇
  2006年   15篇
  2005年   10篇
  2004年   11篇
  2003年   7篇
  2002年   4篇
  2001年   7篇
  2000年   6篇
  1999年   4篇
  1998年   3篇
  1997年   4篇
  1996年   1篇
  1995年   1篇
  1994年   1篇
  1993年   3篇
  1992年   3篇
  1991年   2篇
  1990年   1篇
  1989年   5篇
  1988年   3篇
  1987年   2篇
  1986年   2篇
  1985年   1篇
  1976年   2篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1970年   1篇
  1968年   1篇
  1967年   1篇
  1960年   1篇
  1939年   1篇
  1933年   2篇
排序方式: 共有209条查询结果,搜索用时 15 毫秒
1.
The results of a European Organization for Research and Treatment of Cancer (EORTC) retrospective study on non-Hodgkin's lymphoma (NHL) in elderly patients (greater than or equal to 70 years of age) seen in Europe in 1984 are reported. A precodified form was sent to 55 European institutes in order to evaluate the incidence of NHL in the elderly with regard to natural history, treatment-related toxicity, response, and survival. Thirteen institutes participated in the study. One hundred thirty-seven cases of NHL were observed in the elderly during 1984, making up 28% of the total number of NHL seen in those institutes. The median age was 77 years; 21% of the patients had favorable (low-grade) and 73% unfavorable (intermediate- and high-grade) histology, according to the Working Formulation. Stage at presentation was localized (I and II) in 60% and advanced in 37% of the patients. Most of the physicians used standard therapy regimens at reduced doses, from the beginning of the treatment. Sixty patients (44%) underwent a "conservative" treatment (one or two antineoplastic drugs or local field radiotherapy) and 77 (56%) an "aggressive" treatment (polychemotherapy regimens or extended field radiotherapy). Response was similar between the two treatment groups, but severe and lethal toxicity was significantly higher among patients treated with aggressive therapy. Prospective randomized studies are clearly needed to define the optimal treatment in elderly patients with advanced unfavorable NHL.  相似文献   
2.
目的 真核表达人呼吸道合胞病毒(human respiratory syncytial virus,SV)融合蛋白(fusion protein,),并完成蛋白纯化及纯度测定.方法 根据编码F蛋白的基因序列设计引物,CR方法扩增出3'端带His标签的F基因序列,克隆入pGEM-T-easy载体,经核酸序列分析后,进一步克隆到pcDNA3.1( )真核表达载体,限制性内切酶鉴定,用脂质体Lipofectamine2000转染COS-7细胞,2 h后再用Westem blot检测目的蛋白的表达.Ni柱亲和层析纯化COS-7细胞表达的F蛋白,高效毛细管电泳分析纯化后蛋白纯度.结果 核酸序列分析证实获得带His标签的RSV F基因序列,没有发生无义突变.转染COS-7细胞后,利用Western blot方法检测到F蛋白的特异性条带,纯度达99%以上.结论 初步建立了真核表达RSV F蛋白的纯化方法,为进一步优化RSV F蛋白制备条件及单克隆抗体及诊断试剂等研究奠定了基础.  相似文献   
3.
4.
ObjectiveTo ascertain antimicrobial susceptibility profile of Proteus mirabilis (P. mirabilis) from clinical urine specimens at a university hospital in the spate of its recorded increasing resistance patterns.MethodsThe study was retrospective in nature. Data generated from urine cultures of patients at University of Calabar Teaching Hospital for a period of five years (2004–2009) were compiled. Relevant information obtained were age and gender of patients, organisms recovered and their antibiotic susceptibility patterns. P. mirabilis was identified using standard laboratory procedures.ResultsP. mirabilis showed the highest resistance against ampicillin, cloxacillin, amoxicillin, tetracycline, co-trimoxazole, erythromycin and chloramphenicol (100%–37.2%) while colistin, ofloxacin, ciprofloxacin, ceftriaxone, nalidixic acid and nitrofurantoin recorded the highest activity (59.1%–96.9%) with no drug recording 100% activity. The resistance of the nosocomial isolates of the organism were significantly higher than the community acquired isolates against that of the common antibiotics in use (P<0.05).ConclusionsExtreme caution should be exercised in antibiotic administration in hospital setting and the potential benefits adequately assessed while control of nosocomial infections be given a priority so as to limit the spread of resistant bacteria.  相似文献   
5.
6.
7.
Association of diabetes, serum insulin, and C-peptide with gallbladder disease   总被引:19,自引:0,他引:19  
An inconsistent association has been found between gallbladder disease and diabetes mellitus. We hypothesized that insulin resistance rather than diabetes status may be a primary factor involved in gallstone formation. A total of 5,653 adult participants in the third United States National Health and Nutrition Examination Survey without known diabetes underwent gallbladder ultrasonography and phlebotomy after an overnight fast for measurement of serum insulin, C-peptide, and glucose. Gallbladder disease was defined as ultrasound-documented gallstones or evidence of cholecystectomy. Subjects were characterized as having normal fasting glucose (<110 mg/dL), impaired fasting glucose (110 to <126 mg/dL), or undiagnosed diabetes (>/=126 mg/dL). After controlling for other known gallbladder disease risk factors, among women, undiagnosed diabetes was associated with increased risk of gallbladder disease (prevalence ratio [PR] = 1.91, 95% confidence interval [CI] = 1.29-2. 83); whereas impaired fasting glucose was unassociated. Gallbladder disease risk in women increased with levels of fasting insulin (PR = 1.63, 95% CI = 1.11-2.40) and C-peptide (PR = 2.07, 95% CI = 1.32-3. 25) comparing highest to lowest quintiles. However, the association of gallbladder disease with undiagnosed diabetes was not diminished when the model included fasting insulin (PR = 1.85, 95% CI = 1.24-2. 77). In men, there was a statistically nonsignificant association with undiagnosed diabetes (PR = 2.11, 95% CI = 0.76-5.85), but no association of gallbladder disease with insulin or C-peptide. Among women higher fasting serum insulin levels increased the risk of gallbladder disease, but did not account for the increased risk in persons with diabetes.  相似文献   
8.
Waterston–Cooley anastomosis may be carried out in patients with tricuspid atresia to provide pulmonary perfusion. It is associated with several complications, including preferential blood flow to the right lung, hypoplasia of the left pulmonary artery, obstruction of the anatomosis or rupture of pulmonary aneurysms. We study a patient with thrombosis in the pulmonary arteries following surgical construction of a Waterston shunt in childhood. Imaging findings and clinical symptoms are discussed with emphasis on echocardiogram‐gated multislice spiral CT.  相似文献   
9.
PURPOSE: Previous studies have shown a positive correlation between amount of aortic valve calcification (AVC) and degree of aortic valve stenosis (AVS). We have investigated whether calcium scoring of AVC from contrast-enhanced images is reliable. MATERIAL AND METHODS: Nineteen patients with suspected AVS underwent retrospectively ECG-gated multislice computed tomography (MSCT). Standardized scan protocols were applied prior to (120 KV, 133 mAseff) and after (120 KV, 500 mAseff) the administration of non-ionic contrast material. Image reconstruction was performed at 60% of the RR interval (slice thickness 3 mm, reconstruction increment 2 mm). AVC was quantified using Agatston score and calcium mass. The number of lesions was calculated. All nonenhanced images were scored using thresholds of 130 HU and 350 HU. Contrast-enhanced images were assessed with a threshold of 350 HU exclusively. RESULTS: Fifteen patients with AVCs were included in the statistical analysis. The mean Agatston score (calcium mass) in non-enhanced images was 2888.4 +/- 2844.4 (694.2 mg +/- 869.3 mg). Altering the threshold from 130 HU to 350 HU led to a 58.2% (30.5%) decrease in the AVC score (P values < 0.001). Contrast-enhanced images showed an increased Agatston score (calcium mass) of 56.2% (33.5%) compared to non-enhanced images (P values <0.05) with the same threshold of 350 HU. CONCLUSION: Quantification of AVC from contrast-enhanced images is not reliable, as contrast material simulates calcification.  相似文献   
10.
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