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   4316篇
  免费   231篇
  国内免费   34篇
耳鼻咽喉   62篇
儿科学   95篇
妇产科学   105篇
基础医学   566篇
口腔科学   91篇
临床医学   313篇
内科学   1171篇
皮肤病学   100篇
神经病学   374篇
特种医学   84篇
外科学   340篇
综合类   21篇
预防医学   354篇
眼科学   117篇
药学   339篇
中国医学   30篇
肿瘤学   419篇
  2023年   30篇
  2022年   64篇
  2021年   133篇
  2020年   89篇
  2019年   111篇
  2018年   139篇
  2017年   90篇
  2016年   97篇
  2015年   128篇
  2014年   145篇
  2013年   194篇
  2012年   353篇
  2011年   329篇
  2010年   181篇
  2009年   158篇
  2008年   312篇
  2007年   297篇
  2006年   287篇
  2005年   248篇
  2004年   234篇
  2003年   221篇
  2002年   219篇
  2001年   46篇
  2000年   39篇
  1999年   47篇
  1998年   37篇
  1997年   35篇
  1996年   34篇
  1995年   30篇
  1994年   25篇
  1993年   17篇
  1992年   26篇
  1991年   20篇
  1990年   21篇
  1989年   16篇
  1988年   16篇
  1987年   8篇
  1986年   8篇
  1985年   14篇
  1984年   7篇
  1983年   6篇
  1982年   6篇
  1981年   6篇
  1980年   6篇
  1979年   5篇
  1978年   7篇
  1977年   4篇
  1976年   4篇
  1975年   4篇
  1966年   3篇
排序方式: 共有4581条查询结果,搜索用时 921 毫秒
61.
Background. Studies have suggested that scans with technetium-tagged white blood cells (WBC-Tc99m) may be equal to endoscopy in the assessment of extent and activity of inflammatory bowel disease (IBD). Objective. We have retrospectively examined the accuracy of WBC-Tc99m scans in differentiating continuous from discontinuous colitis in pediatric IBD. Materials and methods. There were 207 children in the study (96 boys, 111 girls, median age 13 years). This included 29 controls – children with no gastrointestinal disease (NL) who underwent WBC-Tc99m scans for other medical problems. Scans were obtained at 30 minutes and 2–4 hours following injection. Scans were interpreted as showing continuous colitis, discontinuous colitis, or no colitis. Results. In the 77 children with active Crohn's disease (CD) of the colon, the scans revealed discontinuous uptake in 63 children and continuous uptake in 14. In the 29 children with ulcerative colitis (UC), 23 scans showed continuous uptake and 6 revealed discontinuous uptake. Two of these 6 showed focal activity near the appendix, and subclinical appendicitis could not be excluded. Another child was bleeding and the scan could have been misinterpreted as showing small- bowel inflammation. In the last three patients, skip areas were clearly identifiable. In none of these last three patients were the biopsies typical of CD (i. e., no granuloma was identified) nor was inflammation patchy. In summary, of the 106 scans showing inflammation, 6 were classified into the wrong group. Conclusion. These data show that WBC-Tc99m scanning can be useful in distinguishing discontinuous from continuous colitis. Received: 20 November 1997 Accepted: 29 May 1998  相似文献   
62.
Urodynamic assessment of the bashful bladder   总被引:2,自引:0,他引:2  
PURPOSE: We prospectively studied the potential contribution of ambulatory urodynamic monitoring in men with urinary symptoms unable to initiate a void on conventional video cystometrography. MATERIALS AND METHODS: A total of 40 consecutive symptomatic men with a median International Prostate Symptom Score of 19 (range 1 to 29) and median age of 51.9 years (range 30 to 75) who were unable to void during video cystometrography underwent ambulatory urodynamic monitoring. Solid-state transducers mounted on silicone coated catheters were inserted urethrally and rectally, and connected to a portable recorder. Subjects voided in private into a specially designed flow meter, which they connected to the recording device. RESULTS: Of the patients 2 (5%) failed to attend ambulatory urodynamic monitoring, despite multiple reminders, and in 1 (2.5%) the trace was uninterpretable. Pressure flow data were available for the remaining 37 patients with mean plus or minus standard deviation 2.72+/-0.1 storage void cycles recorded per patient. All 6 patients (15%) with obstruction were older than 40 years. In 6 cases (15%) obstruction was equivocal and the remainder were unobstructed. Transurethral prostatic resection in 2 and urethrotomy in 1 of 6 patients with obstruction resulted in subjective and objective improvement. CONCLUSIONS: The bashful bladder syndrome was not associated with any specific urodynamic diagnosis. Ambulatory urodynamic monitoring will yield a urodynamic diagnosis in more than 90% of cases after failure to record void data on video cystometrography. A surgically correctable cause of symptoms can be found in about 20% of men older than 40 years. The contribution of ambulatory urodynamic monitoring compared to more conventional evaluation in men younger than 40 years is negligible.  相似文献   
63.
64.
65.
66.
67.
Objective:To identify changes in the prevalence and severity of recurrent wheezing (RW) in infants using data obtained from two surveys administered seven years apart. Methods: A cross-sectional, international, population-based study in infants aged 12–15 months was conducted. Data were obtained from two surveys (S1 and S2, in 2005 and 2012, respectively) using the same methodology in three large Latin American cities: Curitiba (Brazil), São Paulo (Brazil), and Santiago (Chile). Results: A decrease in the overall prevalence of RW was identified between S1 (23.3%) and S2 (20.4%), p = 0.004, but it was mainly driven by the reduction observed in São Paulo; in Curitiba and Santiago, this change was not significant. The mean prevalence of the following RW severity indicators remained high and stable: severe wheezing episodes (56.9% in S1 and 54.2% in S2, p = 0.32) and emergency department (ED) visits for wheezing (S1 = 68.1%, S2 70.9%, p = 0.21). A significant increase in admissions for wheezing (21.1% to 26.7%, p = 0.004) was observed. In Curitiba and São Paulo, there were significant increases in the prevalence of physician-diagnosed asthma and in the use of inhaled corticosteroids and oral antileukotrienes. Conclusions: The prevalence and severity of RW during the first year of life remained high over time, with remarkably high rates of ED visits, admissions for wheezing and use of asthma medications. This study suggests the need for considering early asthma diagnosis and to establish an appropriate treatment in infants with recurrent and severe asthma-like symptoms.  相似文献   
68.
69.
70.
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