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   675997篇
  免费   64673篇
  国内免费   2995篇
耳鼻咽喉   12075篇
儿科学   22500篇
妇产科学   16199篇
基础医学   89713篇
口腔科学   16212篇
临床医学   71708篇
内科学   142687篇
皮肤病学   19573篇
神经病学   51328篇
特种医学   25095篇
外国民族医学   63篇
外科学   119674篇
综合类   9267篇
现状与发展   72篇
一般理论   135篇
预防医学   47071篇
眼科学   15857篇
药学   42997篇
中国医学   1186篇
肿瘤学   40253篇
  2021年   6610篇
  2020年   8151篇
  2019年   5927篇
  2018年   12683篇
  2017年   11122篇
  2016年   12532篇
  2015年   13096篇
  2014年   21701篇
  2013年   25422篇
  2012年   19248篇
  2011年   20634篇
  2010年   19003篇
  2009年   22097篇
  2008年   20146篇
  2007年   19412篇
  2006年   21986篇
  2005年   18699篇
  2004年   17613篇
  2003年   15886篇
  2002年   15764篇
  2001年   28204篇
  2000年   28400篇
  1999年   24011篇
  1998年   9083篇
  1997年   8151篇
  1996年   8379篇
  1995年   7828篇
  1994年   6232篇
  1993年   5704篇
  1992年   17234篇
  1991年   17830篇
  1990年   17582篇
  1989年   17085篇
  1988年   15663篇
  1987年   15375篇
  1986年   14559篇
  1985年   13772篇
  1984年   10247篇
  1983年   8818篇
  1979年   9795篇
  1978年   7224篇
  1977年   6208篇
  1976年   5863篇
  1975年   6722篇
  1974年   7888篇
  1973年   7397篇
  1972年   7292篇
  1971年   6898篇
  1970年   6446篇
  1969年   5986篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Eighty-nine cases of chronic bronchitis were matched against167 asymptomatic controls from the glass bangle industry ofFirozabad. Factors of age, social status, smoking habit andduration of exposure were studied. Duration of exposure wasfound to be a factor contributing significantly to the causationof disease. Requests for reprints should be addressed to: Dr B. N. Gupta, Division of Epidemilogy, Industrial Toxicology Research Centre, Mahatma Gandhi Marg, Lucknow P.O. Box 80, 226001, India  相似文献   
62.
63.
Summary: This is the first report of the largest study of blood pressure measurement in pregnancy in a New Zealand population using standardized definitions and methodology. Over 3,800 women who delivered in an 8-month period in the Wellington region were included in the study. Blood pressure measurement and the presence of oedema and proteinuria were recorded from booking until delivery and in the puerperium. Only 2.7% of women were unable to be contacted after delivery for details on outcomes. The results established normal ranges for blood pressure throughout pregnancy. The data show that Mood pressure greater than 140/90 until 35 weeks' gestation is outside 2 standard deviations at all gestations and justifies using these measurements as the definition of hypertension in pregnancy. The fall in blood pressure in the 2nd trimester was less than 1 mm Ffg per week in both the systolic and diastolic pressures. This fall was smaller than previously recorded in other studies. Gestational hypertension was the commonest blood pressure abnormality occurring in 15.2% of the population. This represented 69% of the pregnant women with a hypertensive disorder. The overall incidence of both gestational hypertension and preeclampsia was 18.5% which is higher than reported in other parts of the world. In this study obesity was significantly associated with hypertensive disorders in pregnancy. An arm circumference of >33 cm, one of the measurements of obesity, was found in 6.8% of the study population. Even after the effect of arm circumference was taken into account, hypertensive disorders were also more common in Pacific Island women. Ankle oedema was significantly associated with the development of both gestational hypertension and preeclampsia but the incidence of oedema was noted in only 11.9% of the subjects.  相似文献   
64.
The efficacy and safety of ketoprofen and paracetamol were compared for the treatment of acute migraine in a randomized, double-blind study of 64 patients. Thirty-four patients received ketoprofen 100 mg intramuscularly, and 30 patients received paracetamol 500 mg intramuscularly. Partial or complete relief of pain and other symptoms was achieved 15 to 20 minutes after administration in the ketoprofen group and within 35 minutes in the paracetamol group. Complete relief of pain was achieved within 30 to 40 minutes after ketoprofen in 28 patients (82.5%) compared to 5 patients (17.5%) in the paracetamol group. Six of the patients treated with ketoprofen needed a second dose for complete relief of pain during the 4-hour follow-up period. Side effects were rare and minimal. Our findings suggest that ketoprofen produced statistically significant benefit in the treatment of acute migraine.  相似文献   
65.
In order to satisfy the need to restore the aesthetics, phonetics and comfort and to facilitate optimal hygiene procedures, 20 edentulous patients were treated with a new concept of overdenture therapy on implants ad modum Brånemark. After 24±3.5 months the patients were re‐examined. They were asked to answer a questionnaire and use a Visual Analogue Scale (VAS) to give their opinion on the prosthetic treatment. The results indicate that an implant‐retained overdenture in the maxilla with this design can satisfy the patients needs in aesthetics, phonetics and comfort and can 1 facilitate oral hygiene measures.  相似文献   
66.
67.
68.
69.
A retrospective analysis of results of treatment of 104 patients with fractures of long tubular bones associated with injuries of peripheral nerves has shown complex therapy to be necessary. Main components of this treatment were biogenic stimulators, vitamin B12, spasmolytic and dehydration drugs in combination with electrophoresis with potassium iodide and thermal procedures. Rapid disturbance of conductivity of nerve trunks after trauma should be followed by revision of the given segment of the extremity in order to remove hematoma and make reposition of displaced fragments of the bone, which can provide recovery of the disturbed function of the nerve.  相似文献   
70.
On the basis of experience with the treatment of more than 1,500 patients with post-burn defects, deformities, and trophic ulcers, the authors distinguished types of affection in which the traditional methods are ineffective. These 133 patients were subjected to plasty with ++cutaneo-fascial grafts; the zones of donor areas from which the grafts are taken are determined. Plasty with ++cutaneo-fascial grafts is indicated in defects of the face, deformity of the neck, total adduction contracture of the arm, defect of the breast, and affections of the hand, leg, and foot. Concrete grafts and the site from which they are taken for restoration of certain regions of the body are suggested. ++Cutaneo-fascial grafts make it possible to restore the shape, function, and the skin of the involved region.  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