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   1145篇
  免费   52篇
  国内免费   29篇
耳鼻咽喉   1篇
儿科学   30篇
妇产科学   33篇
基础医学   114篇
口腔科学   24篇
临床医学   88篇
内科学   215篇
皮肤病学   29篇
神经病学   59篇
特种医学   163篇
外科学   101篇
综合类   143篇
预防医学   32篇
眼科学   66篇
药学   76篇
  1篇
肿瘤学   51篇
  2023年   6篇
  2022年   10篇
  2021年   23篇
  2020年   14篇
  2019年   10篇
  2018年   19篇
  2017年   14篇
  2016年   12篇
  2015年   18篇
  2014年   27篇
  2013年   42篇
  2012年   57篇
  2011年   52篇
  2010年   49篇
  2009年   55篇
  2008年   50篇
  2007年   65篇
  2006年   43篇
  2005年   31篇
  2004年   33篇
  2003年   24篇
  2002年   29篇
  2001年   31篇
  2000年   22篇
  1999年   20篇
  1998年   42篇
  1997年   40篇
  1996年   45篇
  1995年   26篇
  1994年   21篇
  1993年   24篇
  1992年   18篇
  1991年   12篇
  1990年   10篇
  1989年   35篇
  1988年   35篇
  1987年   20篇
  1986年   24篇
  1985年   21篇
  1984年   6篇
  1983年   5篇
  1982年   17篇
  1981年   9篇
  1980年   12篇
  1978年   6篇
  1977年   9篇
  1976年   10篇
  1975年   7篇
  1955年   2篇
  1953年   2篇
排序方式: 共有1226条查询结果,搜索用时 0 毫秒
81.
Volumetric rendering is a new approach to three-dimensional (3D) imaging that overcomes many of the drawbacks of currently available surface-rendering systems. Its application on the Pixar Imaging System in two cases of acetabular fracture was assessed to illustrate the features of the technique. The fast-computing architecture and large memory of this system allow rapid generation of a series of high-quality 3D images in each plane of rotation (x or spinal axis, z or somersaulting axis) that can be viewed as independent static images or as an animated real-time video loop. Editing to remove the normal contralateral hemipelvis enhances appreciation of acetabular abnormalities. Every pixel of computed tomographic data is preserved, allowing representation of both soft tissue and bone as translucent overlap. The presentation of data also allows detection of subtle abnormalities and features and minimizes the artifact generation common in surface-rendered images.  相似文献   
82.
黄柏及中成药中小檗碱和巴马亭的高效液相色谱法测定   总被引:6,自引:0,他引:6  
本文以正相高效液相色谱法,用窗口图解技术对色谱条件进行了优化。对黄柏及其中成药中的有效成分——小檗碱、巴马亭的提取、测定条件、标准曲线进行了研究。并对两种含黄柏的中成药样品进行了分析。其中小檗碱的回收率均在97%以上,巴马亭的回收率均在96%以上。  相似文献   
83.
Summary: Two cases of mycotic dermatitis, probably caused by Aspergillus spec, are presented.
Zusammenfassung: Es werden zwei Fälle von Pilzdermatitis, wahrscheinlich hervorgerufen durch Aspergillus, vorgestellt  相似文献   
84.
85.
O'Connor  MK; Brennan  SS; Shanik  DG 《Radiology》1986,158(1):191-194
The incidence of thromboembolitic events in patients undergoing transfemoral angiography was examined using indium-111 labeled platelets. Twenty-seven patients received approximately 300 muCi of autologous labeled platelets at least 3 hours before angiography and were scanned with a gamma camera immediately before and after angiography. All patients were free of clinically obvious complications in the 1-2 day period after angiography. Our results showed evidence of platelet deposition at 21 sites other than the puncture site in 12 (44%) patients. Most platelet deposition (54%) occurred along the region between the puncture site and the aortic bifurcation; 24% occurred at sites not traversed by the catheter. At the puncture site itself, there was substantial platelet uptake in 44% of patients. This study indicates the need for further work in determining the most suitable catheter material and in assessing the efficacy of other measures such as anticoagulant or antiplatelet therapy.  相似文献   
86.
87.
Background: Estimates of the incidence of venous thrombosis (VT) vary, and data on mortality are limited. Objectives: We estimated the incidence and mortality of a first VT event in a general population. Methods: From the residents of Nord‐Trøndelag county in Norway aged 20 years and older (n = 94 194), we identified all cases with an objectively verified diagnosis of VT that occurred between 1995 and 2001. Patients and diagnosis characteristics were retrieved from medical records. Results: Seven hundred and forty patients were identified with a first diagnosis of VT during 516 405 person‐years of follow‐up. The incidence rate for all first VT events was 1.43 per 1000 person‐years [95% confidence interval (CI): 1.33–1.54], that for deep‐vein thrombosis (DVT) was 0.93 per 1000 person‐years (95% CI: 0.85–1.02), and that for pulmonary embolism (PE) was 0.50 per 1000 person‐years (95% CI: 0.44–0.56). The incidence rates increased exponentially with age, and were slightly higher in women than in men. The 30‐day case‐fatality rate was higher in patients with PE than in those with DVT [9.7% vs. 4.6%, risk ratio 2.1 (95% CI: 1.2–3.7)]; it was also higher in patients with cancer than in patients without cancer [19.1% vs. 3.6%, risk ratio 3.8 (95% CI 1.6–9.2)]. The risk of dying was highest in the first months subsequent to the VT, after which it gradually approached the mortality rate in the general population. Conclusions: This study provides estimates of incidence and mortality of a first VT event in the general population.  相似文献   
88.
89.
A study was conducted to examine the clinical signs, hematological, biochemical and histopathological changes in vitamin D(3) toxicity at a dose rate 2 mg/kg b.wt. of vitamin D(3) and to assess the protective effect of Aloe vera in vitamin D(3) toxicity. The clinical signs observed were anorexia, progressive weight loss, difficulty in movement and respiration, diarrhea, epistaxis, subnormal body temperature and nervous signs before death. Mortality was observed in treated rats between day 10 and day 19 of treatment. The gross postmortem changes observed were severe emaciation, white chalky deposits on epicardial surface of heart, pin point white deposits on cortical surface of kidneys with pale yellow discoloration and diffused white deposits on serosal surface of stomach and intestine with bloody ingesta in lumen. The hematological changes included non-significant increase in hemoglobin and total leukocyte count and significant increase in relative neutrophil count. The biochemical changes observed were significant increase in plasma concentration of calcium, phosphorus and blood urea nitrogen, whereas a significant decrease in the concentration of albumin and total plasma protein was observed. The histopathological lesions included calcification of various organs, viz., tongue, stomach, intestines, kidney, heart, aorta, larynx, trachea, lungs, spleen, choroid plexus arteries of brain and vas deferens. The Aloe vera juice (2.5% in drinking water) has no protective effect on vitamin D(3) toxicity (2 mg/kg b.wt.).  相似文献   
90.
OBJECTIVE: Corticosteroids are used in patients with refractory celiac disease. In order to minimize their systemic side effects, we assessed the role of a locally active sustained release corticosteroid with minimal systemic bioavailability in patients with refractory celiac disease in an open labeled noncontrolled study. METHODS: Patients who received budesonide for refractory celiac disease were classified according to whether they were primarily or secondarily unresponsive to the diet, and whether they had a polyclonal (type I) or clonal (type II) expansion of intraepithelial lymphocytes. The response to budesonide was assessed globally and by reduction in bowel movements. RESULTS: Patients (N = 29, 72% female) received budesonide for a mean of 6.7 +/- 8.5 months, 5 patients (18%) had type II disease (clonal T-cell population); 76% responded to the medication, 55% completely. Response occurred when budesonide was used alone or with oral corticosteroids and/or azathioprine. There was an objective improvement in the number of bowel movements in those that responded. Response occurred in those with either primary or secondary refractory disease and in those with type II disease, irrespective of the presence of microscopic colitis (N = 7). There was no improvement in the duodenal biopsy over the study period and there were no side effects of budesonide. CONCLUSIONS: Budesonide may be of value in the management of refractory celiac disease.  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