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   96741篇
  免费   29153篇
  国内免费   1089篇
耳鼻咽喉   2395篇
儿科学   2575篇
妇产科学   2270篇
基础医学   2220篇
口腔科学   5006篇
临床医学   25718篇
内科学   24254篇
皮肤病学   3253篇
神经病学   12401篇
特种医学   3548篇
外科学   18188篇
综合类   107篇
现状与发展   40篇
预防医学   13132篇
眼科学   2081篇
药学   966篇
中国医学   10篇
肿瘤学   8819篇
  2024年   741篇
  2023年   5026篇
  2022年   1098篇
  2021年   2694篇
  2020年   5295篇
  2019年   1990篇
  2018年   6839篇
  2017年   7291篇
  2016年   7867篇
  2015年   7973篇
  2014年   10364篇
  2013年   12017篇
  2012年   3609篇
  2011年   3389篇
  2010年   6753篇
  2009年   9031篇
  2008年   3354篇
  2007年   2297篇
  2006年   3457篇
  2005年   2000篇
  2004年   1402篇
  2003年   1086篇
  2002年   1009篇
  2001年   1859篇
  2000年   1178篇
  1999年   1703篇
  1998年   2065篇
  1997年   1892篇
  1996年   1957篇
  1995年   1691篇
  1994年   1088篇
  1993年   919篇
  1992年   778篇
  1991年   652篇
  1990年   545篇
  1989年   545篇
  1988年   517篇
  1987年   395篇
  1986年   361篇
  1985年   305篇
  1984年   264篇
  1983年   305篇
  1982年   228篇
  1981年   196篇
  1980年   121篇
  1978年   127篇
  1977年   121篇
  1976年   90篇
  1974年   73篇
  1972年   75篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
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   
42.
The introduction of new diagnostic tools for neuroimaging has resulted in the early recognition of congenital brain tumors. In the present report we describe a personal series of 39 children and an International Multicenter Series of 876 children with brain tumors, in whom the diagnosis was obtained during the first 12 months of life. Most of the tumors were located within the supratentorial compartment. In spite of a relatively high operative mortality, surgery still appears to be the more effective therapy. Radiotherapy in this age group is of a scarce value, due to the vulnerability of the infantile brain. At the present time, chemotherapy still plays a controversial role.  相似文献   
43.
Entering the postmodern world in which society is confronting crossroads, paradoxes, and complexity, the health care system is encountering a transformation more comprehensive and revolutionary than has ever been seen before. Analysis of the state of nursing vis a vis these transformations indicates that the current paradigm does not ensure the existence of the profession in the postmodern health care system. That is because of increased difficulties in consolidating the economic and quality issues into the core of nursing, and in understanding the complexity inherent in health related situations.  相似文献   
44.
Background: The bariatric patient exists in dynamic relationship with family members and friends who have considerable influence upon the patient and his or her surgical outcome. When family members and friends behave as intimate saboteurs, they attempt to hamper, hurt, or subvert the bariatric patient's goal of achieving and maintaining a healthy body weight. Successful or not, intimate saboteurs provide significant treatment challenges for the patient and the treatment team. Methods and Patients: Patient profiles provide examples of intimate sabotage. The psychological construct of Family Systems Theory is used as a plausible explanation for the sabotage of friends and family. Conclusions: Multidisciplinary professionals treating the bariatric patient must be aware of the critical influence of intimate saboteurs and the tactics they use to sabotage. Treatment guidelines recommended by Family Systems Theory are presented as strategies to mitigate the influence of intimate saboteurs.  相似文献   
45.
Society often expects mothers and fathers to share equally in the perinatal grief process because the child was a common bond between them. Unfortunately, in perinatal grief, this is not always the case. The mother and the father can experience incongruent grieving and use discordant coping mechanisms. It is important to evaluate these differences to facilitate communication between the distraught parents. Improved communication can in turn facilitate the grieving process.  相似文献   
46.
47.
48.
49.
This study evaluates the potential for endothelial seeding of a collagen-impregnated Dacron graft with or without surface modifiers (fibronectin, heparin) to attach and retain these cells during flow. Human umbilical endothelial cells were harvested, cultured, labeled with Indium111-oxine and seeded onto 30 mm X 4 mm diameter grafts. Six graft surfaces were studied: 1) a collagen-impregnated Dacron graft, HemashieldR (C); 2) C + fibronectin (C + F); 3) C + heparin (C + H); 4) C + F + H; 5) HytrelR + F (Hyt + F); and 6) Hyt + F + H. Radioactive loss determined the percentage attachment and then percentage retention of labeled inoculum after a one-hour in vitro perfusion. Scanning electron and light microscopy demonstrated the endothelium on the graft surface following perfusion. Fibronectin-coated grafts had a significantly higher percentage attachment than those without fibronectin (ANOVA, P less than 0.05). However, the percentage retention following perfusion was similar for all Dacron grafts and statistically inferior to the HytrelR grafts studied (ANOVA, P less than 0.05). SEM evaluation of the C + F + H graft surface was qualitatively the most impressive Dacron surface for seeding, yet was inferior to the HytrelR graft. We conclude that fibronectin benefits the initial attachment of endothelium to collagen-coated Dacron rivaling the HytrelR surface. Fibronectin does not improve percentage retention of the HemashieldR surface during perfusion, therefore, some of its initial benefit is lost.  相似文献   
50.
Directors of nursing at 23 nursing homes with Alzheimer's units in Southwestern Pennsylvania completed a self‐reported survey of 12 questions. Responses from the self‐administered questionnaires (100% response rate) revealed a wide variation in the staff categories assessing the oral health status of newly admitted residents with AD. The respondents described oral examinations that were incomplete when compared to the oral indicators listed in the Minimum Data Set. All nursing homes reported that oral hygiene was provided each day. The number of residents in a facility had a significant effect on the frequency of oral hygiene provided. Only 52% of the facilities reported yearly oral examinations for this population. According to the respondents, dental treatment was typically performed on‐site. The oral health care costs were paid by Medicare, Medicaid, the residents/family members, or by other undescribed resources. Insufficient time, staff, and training, as well as uncooperative behavior, were identified as barriers to optimum oral health care for residents with AD. Additional staff, specialized training, and increased government reimbursement were suggested to improve the oral health care for this group of older adults. For future studies, review of medical records and on‐site evaluation of the oral health care at these facilities should be required to verify the reported practices.  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