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   5989篇
  免费   632篇
  国内免费   56篇
耳鼻咽喉   61篇
儿科学   215篇
妇产科学   110篇
基础医学   954篇
口腔科学   207篇
临床医学   771篇
内科学   991篇
皮肤病学   110篇
神经病学   370篇
特种医学   365篇
外科学   824篇
综合类   198篇
一般理论   6篇
预防医学   638篇
眼科学   85篇
药学   423篇
中国医学   4篇
肿瘤学   345篇
  2022年   48篇
  2021年   85篇
  2020年   54篇
  2019年   65篇
  2018年   100篇
  2017年   94篇
  2016年   96篇
  2015年   95篇
  2014年   174篇
  2013年   224篇
  2012年   206篇
  2011年   253篇
  2010年   180篇
  2009年   174篇
  2008年   210篇
  2007年   310篇
  2006年   218篇
  2005年   205篇
  2004年   211篇
  2003年   182篇
  2002年   178篇
  2001年   219篇
  2000年   205篇
  1999年   160篇
  1998年   139篇
  1997年   112篇
  1996年   117篇
  1995年   94篇
  1994年   87篇
  1993年   76篇
  1992年   105篇
  1991年   120篇
  1990年   120篇
  1989年   123篇
  1988年   116篇
  1987年   121篇
  1986年   103篇
  1985年   97篇
  1984年   92篇
  1983年   78篇
  1982年   53篇
  1980年   53篇
  1979年   65篇
  1978年   61篇
  1977年   64篇
  1976年   56篇
  1975年   62篇
  1974年   49篇
  1973年   64篇
  1971年   49篇
排序方式: 共有6677条查询结果,搜索用时 15 毫秒
81.
Treatment failures in tinea versicolor are common. To keep failures to a minimum, one must be aware of the extent of the disease and treat it in a time-tested but sufficient manner. When applied correctly, selenium sulfide 1.25 percent has proved effective.  相似文献   
82.
Glenohumeral joint: comparison of shoulder positions at MR arthrography   总被引:3,自引:0,他引:3  
Kwak  SM; Brown  RR; Trudell  D; Resnick  D 《Radiology》1998,208(2):375
  相似文献   
83.
The influence of aging on sex differences in psychomotor reminiscence and practice distribution effects was investigated in young (18 to 22 year) and elderly (57 to 86 year) participants within the context of reactive inhibition theory. As predicted by the theory in conjunction with hormonal considerations, aging eliminated the sex differences typically found in young adults, reduced the absolute amount of reminiscence, and diminished the gains in task proficiency arising from practice distribution, progressively so as practice increased. Significant age effects on task proficiency were detectable even within the age span of the elderly adults.  相似文献   
84.
85.
86.
87.
BACKGROUND: Recovery from general anesthesia is governed by pharmacodynamic and pharmacokinetic factors. Gender has not previously been recognized as a factor influencing the time to emergence from general anesthesia. METHODS: This multicenter study was originally designed to measure the effects of the bispectral index on intraoperative anesthetic management and patient recovery. We compared the wake-up and recovery times of 274 adults after propofol/alfentanil/nitrous oxide anesthesia. Patients were randomly assigned to have the titration of propofol performed with or without the use of bispectral index monitoring. Specific guidelines were given for the titration of drugs. The aim in all cases was to provide a safe anesthetic with the fastest possible recovery. RESULTS: There was a significant reduction in propofol dose, time to eye opening, and response to verbal command when the anesthetic was titrated using the bispectral index. Unexpectedly, gender proved to be a highly significant independent predictor for recovery time. Women woke significantly faster than men: the time from end of anesthesia to eye opening was 7.05 versus 11.22 min, P < 0.05, and response to verbal command was 8.12 versus 11.67 min, P < 0.05. These differences were significant at all four study sites and in each treatment group. Men consistently had prolonged recovery times compared to women, P < 0.001. There was no difference in the dose of anesthetic used between gender. CONCLUSIONS: Gender appears to be an important variable in recovery from general anesthesia. These findings may explain the increased reported incidence of awareness in women (three times more frequent) and support the need to include gender as a variable in pharmacokinetic and pharmacodynamic studies of anesthetic drugs.  相似文献   
88.
The purpose of this 2-year longitudinal clinical study was to investigate alveolar (oral) bone height and density changes in osteoporotic/osteopenic women compared with women with normal lumbar spine bone mineral density (BMD). Thirty-eight postmenopausal women completed this study; 21 women had normal BMD of the lumbar spine, while 17 women had osteoporosis or osteopenia of the lumbar spine at baseline. All subjects had a history of periodontitis and participated in 3- to 4-month periodontal maintenance programs. No subjects were current smokers. All patients were within 5 years of menopause at the start of the study. Four vertical bitewing radiographs of posterior sextants were taken at baseline and 2-year visits. Radiographs were examined using computer-assisted densitometric image analysis (CADIA) for changes in bone density at the crestal and subcrestal regions of interproximal bone. Changes in alveolar bone height were also measured. Radiographic data were analyzed by the t-test for two independent samples. Osteoporotic/osteopenic women exhibited a higher frequency of alveolar bone height loss (p<0.05) and crestal (p<0.025) and subcrestal (p<0.03) density loss relative to women with normal BMD. Estrogen deficiency was associated with increased frequency of alveolar bone crestal density loss in the osteoporotic/osteopenic women and in the overall study population (p<0.05). These data suggest that osteoporosis/osteopenia and estrogen deficiency are risk factors for alveolar bone density loss in postmenopausal women with a history of periodontitis. Received: 9 April 1998 / Accepted: 18 August 1998  相似文献   
89.
PURPOSE: Following ambulatory surgery, long-acting analgesics may provide advantages over short-acting analgesics. This study compared controlled-release codeine (CC) and acetaminophen plus codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period following laparoscopic cholecystectomy. METHODS: Eligible patients were randomized to CC or A/C in a double-blind, double-dummy parallel group study. Unrelieved pain in hospital was treated with fentanyl i.v. bolus. Pain [100 mm visual analogue scale (VAS)] was assessed before the first dose of medication; at 0.5, one, two, three, and four hours post-dose; at discharge; and three times a day for 48 hr. Adverse events were recorded and measures of patient satisfaction were assessed at the end of the study. RESULTS: Eighty-four patients were enrolled in the study; 42 patients in each group. There were no statistically significant differences between CC and A/C treatment. Mean VAS baseline pain was similar in both groups (P = 0.49) and there was no significant difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, the mean VAS pain score was significantly reduced from baseline in both groups (P = 0.0001). The VAS pain scores at discharge were reduced 59% and 56% from baseline, respectively (P = 0.61). There was no difference between treatments in the incidence of adverse events and patients reported similar levels of satisfaction. CONCLUSIONS: Controlled-release codeine provides an equivalent onset of analgesia, reduction in postoperative pain, and level of patient satisfaction, to acetaminophen plus codeine, over 48 hr following cholecystectomy, with the advantage of less frequent dosing.  相似文献   
90.
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