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   705895篇
  免费   48870篇
  国内免费   1305篇
耳鼻咽喉   9166篇
儿科学   23267篇
妇产科学   17606篇
基础医学   110406篇
口腔科学   19964篇
临床医学   63749篇
内科学   134299篇
皮肤病学   16163篇
神经病学   49434篇
特种医学   25767篇
外国民族医学   76篇
外科学   104466篇
综合类   14829篇
现状与发展   2篇
一般理论   160篇
预防医学   51391篇
眼科学   16335篇
药学   53957篇
  3篇
中国医学   2359篇
肿瘤学   42671篇
  2019年   5432篇
  2018年   7865篇
  2017年   6105篇
  2016年   6821篇
  2015年   7553篇
  2014年   10266篇
  2013年   15388篇
  2012年   20496篇
  2011年   21487篇
  2010年   12719篇
  2009年   11931篇
  2008年   19988篇
  2007年   21507篇
  2006年   21902篇
  2005年   20440篇
  2004年   19990篇
  2003年   18940篇
  2002年   18452篇
  2001年   36329篇
  2000年   36897篇
  1999年   30379篇
  1998年   7875篇
  1997年   6662篇
  1996年   6972篇
  1995年   6627篇
  1994年   6096篇
  1993年   5589篇
  1992年   22971篇
  1991年   22926篇
  1990年   22311篇
  1989年   22081篇
  1988年   20040篇
  1987年   19420篇
  1986年   18467篇
  1985年   17308篇
  1984年   12697篇
  1983年   10742篇
  1982年   5923篇
  1979年   11518篇
  1978年   8129篇
  1977年   6832篇
  1976年   6594篇
  1975年   7269篇
  1974年   8498篇
  1973年   8141篇
  1972年   7663篇
  1971年   7127篇
  1970年   6877篇
  1969年   6308篇
  1968年   5780篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Persistent hip stiffness in Perthes’ disease indicates a poor prognosis and is a therapeutic challenge. We report a case of a 13-year-old boy with a stiff Perthes’ hip that was nonresponsive to prolonged nonsurgical treatment. Imaging revealed Catterall group IV Perthes’ disease in an advanced reossification stage, with a focal defect in the weight-bearing area of the capital femoral epiphysis. A focal, compressible chondral elevation was detected on hip arthroscopy; on incision, flocculent fluid was released. After the cyst was excised, microfracture revascularization of the chondral defect was undertaken. Postoperatively, the patient had immediate pain relief, correction of deformity, and restoration of painless range of motion; this has continued for 4 years since surgery was performed. Persistence of an unhealed necrotic segment in Perthes’ disease has traditionally been associated with osteochondritis dissecans; however, in this case, the unhealed and nonossified segment produced an elevated painful chondral cyst that caused spasm and stiffness of the hip. Although 2 distinct types of chondral lesions have been described in Perthes’ disease, stiffness arising because of these lesions has not been reported. Patients with this unusual third type of chondral lesion of the capital femoral epiphysis, which causes persistent stiffness in Perthes’ hip, may be identified and successfully treated with the use of arthroscopic techniques.  相似文献   
992.
993.
994.
995.
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   
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