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   445570篇
  免费   32097篇
  国内免费   12538篇
耳鼻咽喉   4359篇
儿科学   11626篇
妇产科学   7099篇
基础医学   35581篇
口腔科学   8522篇
临床医学   50160篇
内科学   54535篇
皮肤病学   4887篇
神经病学   26480篇
特种医学   13902篇
外国民族医学   122篇
外科学   52821篇
综合类   70904篇
现状与发展   25篇
一般理论   30篇
预防医学   40081篇
眼科学   6137篇
药学   39612篇
  447篇
中国医学   35230篇
肿瘤学   27645篇
  2024年   1486篇
  2023年   7369篇
  2022年   13330篇
  2021年   18353篇
  2020年   16837篇
  2019年   21810篇
  2018年   19309篇
  2017年   16935篇
  2016年   14709篇
  2015年   14122篇
  2014年   26832篇
  2013年   29036篇
  2012年   24693篇
  2011年   26706篇
  2010年   21620篇
  2009年   19942篇
  2008年   19552篇
  2007年   20086篇
  2006年   17861篇
  2005年   15540篇
  2004年   12554篇
  2003年   10994篇
  2002年   8783篇
  2001年   7879篇
  2000年   6475篇
  1999年   5460篇
  1998年   4516篇
  1997年   4331篇
  1996年   3689篇
  1995年   3384篇
  1994年   3174篇
  1993年   2518篇
  1992年   2519篇
  1991年   2134篇
  1990年   1899篇
  1989年   1676篇
  1988年   1557篇
  1987年   1350篇
  1985年   4000篇
  1984年   4945篇
  1983年   3445篇
  1982年   3911篇
  1981年   3651篇
  1980年   3253篇
  1979年   2968篇
  1978年   2576篇
  1977年   1942篇
  1976年   2179篇
  1975年   1657篇
  1974年   1434篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Quality of life (QoL) is an important consideration among asthma sufferers. The Pediatric Asthma Quality of Life Questionnaire (PAQLQ) is one of the most widely used instruments for measuring health-related QoL in children with asthma. The standardized version of PAQLQ contains 23 questions in three domains, i.e., activity limitation, symptoms and emotional function. The objective of this study was to validate the Thai-translated version of the PAQLQ. The study design consisted of a five-week single cohort study. Patients recorded symptoms, and peak expiratory flow rate (PEFR) each morning and evening during the first and fifth week of the study in asthma diary. At each clinic visit, a trained-interviewer administered the PAQLQ and performed spirometric measurements. Fifty-one children, ages between 7 and 17 yr participated in the study. Scores from the asthma diary were used to classify patients into stable vs. unstable groups. The construct validity of the questionnaire was confirmed in both cross-sectional and longitudinal studies by demonstrating correlations between various PAQLQ domains with clinical asthma parameters (asthma diary, beta-agonist use and PEFR). There was high internal consistency for scores of the three domains (Cronbach's alpha-coefficient = 0.83-0.95). For those with stable asthma, the reliability of PAQLQ was good for the rating scale (intra-class correlation coefficient--ICC = 0.84) and for total score (alpha = 0.97) indicating high reproducibility of the PAQLQ. The significant difference of changes QoL scores between stable and unstable groups was observed in all domains. We conclude that the Thai version of PAQLQ is valid and reliable for implementing in Thai children with asthma.  相似文献   
12.
Intraductal papillary mucinous tumor (IPMT) of the pancreas is characterized by slow growth and a relatively favorable prognosis, however, invasive cancer originating in an IPMT is associated with a poor prognosis. Although various parameters in imaging modalities have been advocated to differentiate between benign IPMN and malignant ones, it is not easy to obtain definite diagnosis based on these parameters. Peroral pancreatoscopy (POPS) allows a clear and direct visualization of the pancreatic duct, providing useful information regarding tumor nature in IPMT. The authors have studied the usefulness of POPS in the diagnosis of IPMT. Nevertheless, its usefulness is not necessarily widely accepted and the significance of POPS is still controversial. In this review, the authors intended to address the diagnostic value of POPS and to clarify its role in the diagnosis of IPMT. The authors think treatment of IPMT can be improved by introducing POPS because the determination of surgical procedure as well as the area of resection based on the preoperative diagnosis of the involvement of the main pancreatic duct and branch duct is inevitable.  相似文献   
13.
14.
机械通气治疗小儿急性肺损伤   总被引:1,自引:0,他引:1  
目的:探讨小儿急性肺损伤(ALI)的临床治疗。方法:对本院综合ICU1998年4月至2002年4月发生的22例小儿ALI的临床治疗情况进行回顾性分析。结果:本组22例小儿ALI采用呼吸末正压机械通气(PEEP)联合大剂量甲基强的松龙冲击治疗,有效率为86.36%;3例死亡,死亡率为13.64%,死于多器官功能不全综合征(MODS)。结论:机械通气治疗小儿ALI应选择最佳PEEP,动态监测动脉血气指标和X线胸片,在综合治疗基础上加用大剂量甲基强的松龙冲击治疗能收到较好的疗效。  相似文献   
15.
目的治疗顽固性下颌磨牙根尖周炎。并尽量减少对牙周膜的机械性损伤。方法采用下牙槽神经阻滞麻醉,并配合局部麻醉。拔牙钳的尖置放于釉牙骨质界以上,采用颊舌向摆动的方式将患牙拔下。在不断滴有生理盐水的条件下,立即用高速车针磨除患牙根尖2 ̄3mm的牙体组织,根管内3 ̄5mm深的充填物要用圆钻将其清除,再用牙胶尖和氢氧化钙糊剂充填。将患牙再植入牙槽窝之前,务必用生理盐水将牙槽窝冲洗干净,要求严格控制在15分钟内完成再植,并尽量减少对牙周膜的机械性损伤。再植牙齿一般不需要夹板固定,必要时可采用缝线缝合固定。结果我们选择的5例患者,术后随访1 ̄2年,1例患者再植失败,4例患者再植成功。结论特异性再植术治疗顽固性下颌磨牙根尖周炎疗效理想,而且较易掌握。  相似文献   
16.
Consecutive patients (n = 215) who were referred to optometric (55%) or multidisciplinary (45%) low-vision services and above 50 years of age were recruited from four hospitals in the Netherlands. They completed two vision-related quality of life questionnaires, the Vision Quality of Life Core Measure (VCM1) and the Low Vision Quality of Life Questionnaire (LVQOL), before their first visit with low-vision services and 1 year later. At follow-up, patients referred to multidisciplinary low-vision services had lower scores on the mobility subscale of the LVQOL than patients referred to optometric low-vision services [5.3 points; 95% confidence interval (CI): 0.2-10.5]. Paired sample t-tests for the two groups of patients taken together show improvement for the VCM1 (3.1 points; 95% CI: 0.6-5.6) and deterioration for the basic aspects of vision (3.5 points; 95% CI: 1.1-5.9) and the mobility (6.6 points; 95% CI: 3.7-9.5) subscales of the LVQOL. In conclusion, people referred to optometric services showed less deterioration in mobility than those referred to multidisciplinary services. No differences were observed for any of the other subscales of the LVQOL and the VCM1. Future research in this field should include randomized controlled designs comparing low-vision services with no treatment or placebo.  相似文献   
17.
医源性胆管狭窄X线表现   总被引:1,自引:0,他引:1  
本文报道了13例医源性胆管狭窄,分析其影像表现。特点为:环形狭窄;线样狭窄,包括规则的和不规则的线样狭窄;闭塞性狭窄;胆管闭塞和胆管中断分离。ERCT和PCT对狭窄的形态,位置及长度显示优于CT和US。  相似文献   
18.
The present study evaluates the response comparability between 361 elderly hip fracture patients admitted from the community to seven Baltimore area hospitals between 1984 and 1986 and interviewer selected proxies on items pertaining to patients' pre-fracture health and functional status. Agreement across items ranges from very poor to good and varies with respect to the health or functional area assessed. Proxies tend to overestimate patient disability relative to the patients themselves, especially with regard to capacity to perform instrumental activities of daily living. Although proxies who report the greatest contact with patients respond most comparably to the patients, when they do disagree, proxies with the greatest patient contact tend to overestimate patient disability. The authors suggest that attention to item construction and phrasing may improve response comparability.  相似文献   
19.
One of the pyrimidine compounds, 2-piperadino-6-methyl-5-oxo-5,6-dihydro(7H)pyrrolo[3,4-d]pyrimidine (MS-818), has neurotropic effects in vitro. Therefore, we studied the effect of MS-818 on the regeneration of the peroneal nerve in C57BL/6J mice after a crush injury. Two test groups, which received a daily intraperitoneal injection of 5 mg/kg or 10 mg/kg MS-818, respectively, were compared with controls, which received daily intraperitoneal injections of physiological saline, over a 14-day period. The maximum foot-width ratio (crushed side/uncrushed side) was obtained on days 1, 8 and 14 after the crush injury, and the various morphometric parameters were evaluated at both 5 and 10 mm distal to the proximal portion of the crush site. The significant effects of MS-818 included a larger maximum foot width (P<0.04) and a greater number of unmyelinated axons per nerve at both levels (P<0.003) in both test groups than in controls. MS-818 had no significant effects on body weight, the increase of total transverse fascicular area after the crush injury, the total number of myelinated fibers with their size distributions, or the number of nuclei of Schwann cells and macrophages. Therefore, we conclude that MS-818 promotes axonal sprouting and elongation after a crush injury in mice.  相似文献   
20.
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