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   198673篇
  免费   11763篇
  国内免费   537篇
耳鼻咽喉   2477篇
儿科学   6422篇
妇产科学   4228篇
基础医学   27155篇
口腔科学   8014篇
临床医学   15725篇
内科学   44530篇
皮肤病学   4906篇
神经病学   17002篇
特种医学   5789篇
外国民族医学   26篇
外科学   23949篇
综合类   1565篇
现状与发展   1篇
一般理论   92篇
预防医学   20739篇
眼科学   3488篇
药学   12229篇
中国医学   748篇
肿瘤学   11888篇
  2023年   1123篇
  2022年   2380篇
  2021年   4509篇
  2020年   3021篇
  2019年   4336篇
  2018年   5784篇
  2017年   4300篇
  2016年   4144篇
  2015年   4798篇
  2014年   6499篇
  2013年   8210篇
  2012年   12822篇
  2011年   13376篇
  2010年   6845篇
  2009年   6128篇
  2008年   10354篇
  2007年   11033篇
  2006年   10346篇
  2005年   10481篇
  2004年   9841篇
  2003年   8966篇
  2002年   6883篇
  2001年   5276篇
  2000年   5270篇
  1999年   4678篇
  1998年   1789篇
  1997年   1447篇
  1996年   1429篇
  1995年   1225篇
  1994年   1199篇
  1993年   1089篇
  1992年   2786篇
  1991年   2690篇
  1990年   2457篇
  1989年   2461篇
  1988年   2196篇
  1987年   2031篇
  1986年   1909篇
  1985年   1829篇
  1984年   1329篇
  1983年   1064篇
  1982年   607篇
  1981年   555篇
  1980年   535篇
  1979年   971篇
  1978年   670篇
  1977年   509篇
  1975年   581篇
  1974年   600篇
  1973年   589篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
Within the context of early diagnosis of Alzheimer's disease (AD), there is a growing interest in neuropsychological screening tests. Amongst these tests, we focused on the largely used Memory Impairment Screen (MIS). The objective of the present work was to show that adding a 10-min delayed recall to the MIS, improves the test psychometric characteristics in order to detect dementia in the earliest stages. A prospective study was carried out on a cohort of 270 consecutive elderly ambulatory subjects attending the Broca Hospital Memory Clinic: normal controls ( n  = 67), mild cognitive impairment subjects ( n  = 98) and mildly demented patients [ n  = 105, Mini Mental State Examination (MMSE) = 23 ± 4]. This study consisted in testing the advantage of the 10-min delayed recall entitled MIS-D compared with the MIS. At a cut-off score of 6, the MIS-D revealed satisfying psychometric characteristics with a sensitivity of 81% and a specificity of 91%, whilst the MIS alone indicated a sensitivity of 60% and a specificity of 88% in detecting dementia. In demented patients with MMSE score ≥26, MIS-D properties still remained satisfying (sensitivity: 75%, specificity: 92%). MIS-D is a more relevant screening test than MIS alone at very early stages of dementia.  相似文献   
82.
Background. The European Community Respiratory Health Survey (ECRHS) questionnaire was planned to answer questions about the distribution of asthma. Our objective was to determine the cultural equivalence of the ECRHS into the Brazilian-Portuguese language. Methods. We translated the ECRHS according to international criteria. Results. Small cultural adaptations were necessary. Among the 80 participating patients, the Cronbach indices were higher (0.98-1.00) and the Kappa indices varied from 0.77 to 1.00. Conclusion. The study suggests that the Brazilian version of the ECRHS is conceptually equivalent to the original and similarly reliable and may be used in international studies involving Portuguese-speaking respiratory patients.  相似文献   
83.
Chronic intestinal pseudo-obstruction (CIPO) is a rare pathological condition characterized by a marked derangement of gut propulsive motility mimicking mechanical obstruction, in the absence of any lesion occluding the gut lumen. This disease is often associated with a disabling and potentially life-threatening complications and is still too often unrecognized even in referral centres. As a result, patients receive neither appropriate care nor recognition of their severe health condition. Medical and surgical therapies are often unsatisfactory and long-term outcome turns out to be poor in the vast majority of cases. This article focuses on the main clinical features, the management and long-term outcome of patients affected by CIPO, with particular emphasis on those aspects which remain a matter of debate.  相似文献   
84.
85.
The value of maternal C-reactive protein (CRP) levels as predictors of fetal and maternal infective morbidity and fetal mortality was assessed prospectively over a 6-month period in all cases of premature rupture of the fetal membranes or suspected premature labour. Statistical analysis of results showed that CRP at a level of 1.32 mg/dl is a sensitive marker of infective morbidity in mother and neonate. Furthermore, there was a significant association between raised CRP levels and low-birth-weight babies, suggesting that intra-uterine infection is a major cause of prematurity in the study population.  相似文献   
86.
87.
88.
Gastrogastric fistula: a possible complication of Roux-en-Y gastric bypass.   总被引:4,自引:0,他引:4  
BACKGROUND: Gastrogastric fistula is a communication between the proximal gastric pouch and the distal gastric remnant, rarely described in the realm of bariatric procedures. The aim of this study was to review the existing literature about this topic and to demonstrate its laparoscopic treatment. METHODS: An extensive literature review found several articles reporting this complication. However, no citation was found describing the steps of the laparoscopic management of this situation. RESULTS: Gastrogastric fistula occurs in up to 6% of Roux-en-Y gastric bypasses. Two theories exist for fistula formation: (1) it is a technical complication derived from the incomplete division of the stomach during the creation of the pouch, and (2) it occurs after a staple-line failure, developing a leak with an abscess, which then drains into the distal stomach forming the fistula. Early symptoms include fever, tachycardia, and abdominal pain. Failure in weight loss is a late clinical sign observed in these patients. Diagnosis is based on radiologic study, upper endoscopy and computed tomography. When identified in the acute postoperative course, laparoscopic treatment is easy. Chronic fistulas are difficult to manage, and the laparoscopic approach is an alternative to open surgery. CONCLUSIONS: Gastrogastric fistula is a possible complication of Roux-en-Y gastric bypass and its laparoscopic treatment is feasible.  相似文献   
89.
90.
Efficacy and safety of mycophenolate mofetil (MMF) may be optimized with individualized doses based on therapeutic monitoring of its active metabolite, mycophenolic acid (MPA). In this 12-month study, 137 renal allograft recipients from 11 French centers receiving basiliximab, cyclosporine A, MMF and corticosteroids were randomized to receive either concentration-controlled doses or fixed-dose MMF. A novel Bayesian estimator of MPA AUC based on three-point sampling was used to individualize doses on posttransplant days 7 and 14 and months 1, 3 and 6. The primary endpoint was treatment failure (death, graft loss, acute rejection and MMF discontinuation). Data from 65 patients/group were analyzed. At month 12, the concentration-controlled group had fewer treatment failures (p = 0.03) and acute rejection episodes (p = 0.01) with no differences in adverse event frequency. The MMF dose was higher in the concentration-controlled group at day 14 (p < 0.0001), month 1 (p < 0.0001) and month 3 (p < 0.01), as were median AUCs on day 14 (33.7 vs. 27.1 mg*h/L; p = 0.0001) and at month 1 (45.0 vs. 30.9 mg*h/L; p < 0.0001). Therapeutic MPA monitoring using a limited sampling strategy can reduce the risk of treatment failure and acute rejection in renal allograft recipients 12 months posttransplant with no increase in adverse events.  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