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   872055篇
  免费   64335篇
  国内免费   14023篇
耳鼻咽喉   10463篇
儿科学   24798篇
妇产科学   19263篇
基础医学   129739篇
口腔科学   22803篇
临床医学   86348篇
内科学   158378篇
皮肤病学   17759篇
神经病学   58014篇
特种医学   31770篇
外国民族医学   193篇
外科学   120975篇
综合类   45101篇
现状与发展   58篇
一般理论   167篇
预防医学   62621篇
眼科学   21236篇
药学   71583篇
  134篇
中国医学   12660篇
肿瘤学   56350篇
  2022年   9501篇
  2021年   14535篇
  2020年   10129篇
  2019年   11040篇
  2018年   13826篇
  2017年   11380篇
  2016年   11832篇
  2015年   15320篇
  2014年   19806篇
  2013年   23632篇
  2012年   32625篇
  2011年   34935篇
  2010年   21062篇
  2009年   18586篇
  2008年   28563篇
  2007年   30025篇
  2006年   30244篇
  2005年   28870篇
  2004年   25472篇
  2003年   24008篇
  2002年   22791篇
  2001年   40000篇
  2000年   40792篇
  1999年   34519篇
  1998年   10693篇
  1997年   9445篇
  1996年   9104篇
  1995年   8654篇
  1994年   7839篇
  1993年   6664篇
  1992年   24302篇
  1991年   23972篇
  1990年   23219篇
  1989年   22898篇
  1988年   20749篇
  1987年   20009篇
  1986年   18982篇
  1985年   17684篇
  1984年   12863篇
  1983年   10881篇
  1979年   11585篇
  1978年   8128篇
  1977年   6834篇
  1976年   6594篇
  1975年   7268篇
  1974年   8500篇
  1973年   8143篇
  1972年   7658篇
  1971年   7127篇
  1970年   6877篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
993.
994.
AIMS: The efficacy of three education programmes for Type 2 diabetic patients was tested in a randomized trial. A didactic-oriented training programme (treatment A) was compared with a self-management-oriented programme delivered in group sessions (treatment B). The latter programme was compared with a more individualized approach (treatment C). METHODS: One hundred and eighty-one Type 2 diabetic patients (age 55.6 +/- 6.3 years, diabetes duration 6.6 +/- 6.2 years, HbA(1c) 7.8 +/- 1.6%, female 49.7%) took part. Efficacy was assessed 3 months (t1) after baseline (t0) and at a follow-up 15 months (t2) after baseline. RESULTS: The fall in HbA(1c) in treatment B at t1 was sustained at t2 (t0 8.1 +/- 1.8%, t1 7.3 +/- 1.7%, t2 7.4 +/- 1.9%). In treatment A, HbA(1c) was unchanged throughout (t0 7.6 +/- 1.5%, t1 7.5 +/- 1.3%, t2 7.7 +/- 1.7%; treatment A vs. treatment B; P < 0.05). With the more individualized approach of treatment C, there was a fall in HbA(1c) at t1, but this was not sustained at t2 (t0 7.8 +/- 1.6%, t1 7.1 +/- 1.3%, t2 7.6 +/- 1.6%; treatment B vs. treatment C; P = 0.73). There were also significant benefits in treatment B subjects compared with treatment A in further medical (body mass index and fasting blood glucose), psychological (control, irritability and hunger dependency of eating behaviour, and trait anxiety) and behavioural (exercise) variables. There were no significant benefits of the more individualized treatment C compared with group treatment B. No significant differences were found regarding triglyceride levels, high-density lipoprotein, diabetes-related knowledge, negative well-being, urine or blood glucose levels or foot care. CONCLUSION: Self-management training had a significantly higher medium-term efficacy than didactic diabetes education. The group sessions were more effective than a more individualized approach.  相似文献   
995.
OBJECTIVE: To study the cellular expression of CD45RO, CD20, CD68 and proliferating cell nuclear antigen (PCNA) in nasal polyps. METHODS: Nasal polyp tissues from 50 patients were evaluated for cellular expression of CD45RO, CD20, CD68 and PCNA using immunohistochemistry SP by counting the average number in 5 chosen high-power fields, Histopathological observations were combined with HE. Analyses were performed on SPSS10.0. RESULTS: CD68+ cells were expressed more in nasal polyps dominated by eosinophils than by neutrophils(P < 0.05). There was no difference between CD45RO and CD20, but both of them had negative correlation(P = 0.05). Significant correlation was found between CD68+ cells and eosinophils or PCNA positive cells on epithelium. PCNA positive cells on epithelium had significant correlation on fibroblast (P < 0.05). CONCLUSION: Inflammatory cell infiltration (eosinophilia CD45RO, CD20, CD68) and cell proliferating in epithelium cells, glandular cell and fibroblast are strongly correlated with formation of nasal polyps. The nasal polyps are not only characteristic of eosinophilia but also by lymphocytes dominated by CD45RO and CD68 positive cells. CD68 may be stem cell of nasal polyp.  相似文献   
996.
Extended healing time and lack of documented effective treatments of sacrococcygeal pilonidal disease create substantial problems. Locally applied zinc oxide has been reported to promote wound healing. We have compared topical zinc oxide (3%) with placebo meshes for pilonidal wounds healing by secondary intention in a randomized, double‐blind, placebo‐controlled multicenter trial. Sixty‐four consecutive patients, 53 males, aged between 18 and 60 years (median 26 years) with excised pilonidal wounds were centrally randomized to local zinc oxide (30 mg/g, n = 33) or to placebo (n = 31) mesh treatment. Patients were followed with strict recording of beneficial and harmful effects. The median healing times were 54 days (42–71 days, interquartile range, n = 33) for the zinc group and 62 days (55–82 days, n = 31) for the placebo group. This difference was not statistically different (p = 0.32). Based on Cox regression analysis initial wound volume influenced healing negatively (p = 0.016) while smoking (p = 0.011) was associated with faster wound healing. Significantly (p < 0.01) more placebo (n = 12) than zinc oxide‐treated patients (n = 3) needed antibiotics postoperatively. Although topical zinc oxide increased (p < 0.001) wound fluid zinc levels (1830 ± 405 μM, mean ± SEM) compared with placebo (3.1 ± 1.6 μM) serum‐zinc levels did not differ significantly between the zinc (13.5 ± 0.4 μM) and placebo (12.8 ± 0.4 μm) groups on postoperative day 7. No adverse events were recorded. Topical zinc oxide treatment did not accelerate time to closure of open pilonidal wounds but was associated with reduced antibiotic usage.  相似文献   
997.
998.
The relationship of large and vascularized chorioangiomas to adverse pregnancy outcome is well recognized. We present a patient with a large placental tumor and signs of impending fetal cardiac failure. The angioarchitecture of the tumor depicted by three-dimensional (3D) power Doppler ultrasound enabled us to accurately diagnose a placental chorioangioma. During the follow-up period, quantitative flow data obtained using 3D power Doppler indicated altered hemodynamics in the tumor and concomitant improvement in the condition of the fetus, enabling us to manage the mother conservatively. Spontaneous delivery occurred at 38 weeks without any complications. This report demonstrates the potential value of 3D power Doppler in prenatal diagnosis and monitoring of pregnancies complicated by large, vascularized chorioangioma.  相似文献   
999.
1000.
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