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   1334635篇
  免费   102047篇
  国内免费   4264篇
耳鼻咽喉   16823篇
儿科学   43594篇
妇产科学   36370篇
基础医学   198006篇
口腔科学   35917篇
临床医学   129706篇
内科学   258271篇
皮肤病学   26387篇
神经病学   111929篇
特种医学   48256篇
外国民族医学   366篇
外科学   184211篇
综合类   28780篇
现状与发展   1篇
一般理论   460篇
预防医学   114450篇
眼科学   29000篇
药学   98916篇
  6篇
中国医学   3172篇
肿瘤学   76325篇
  2021年   10968篇
  2019年   11685篇
  2018年   16365篇
  2017年   12320篇
  2016年   13276篇
  2015年   15228篇
  2014年   20847篇
  2013年   32113篇
  2012年   44326篇
  2011年   46970篇
  2010年   27117篇
  2009年   24969篇
  2008年   42773篇
  2007年   45128篇
  2006年   45231篇
  2005年   43647篇
  2004年   41613篇
  2003年   39540篇
  2002年   38338篇
  2001年   60863篇
  2000年   62533篇
  1999年   52298篇
  1998年   14588篇
  1997年   13284篇
  1996年   13122篇
  1995年   12462篇
  1994年   11628篇
  1993年   10924篇
  1992年   41580篇
  1991年   40766篇
  1990年   39451篇
  1989年   37345篇
  1988年   34589篇
  1987年   33694篇
  1986年   32158篇
  1985年   30641篇
  1984年   23037篇
  1983年   19591篇
  1982年   11752篇
  1979年   20806篇
  1978年   14814篇
  1977年   12064篇
  1976年   11876篇
  1975年   12110篇
  1974年   14804篇
  1973年   14473篇
  1972年   13360篇
  1971年   12422篇
  1970年   11489篇
  1969年   10414篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
942.
OBJECTIVES: The aim of the study was to check and present data on the relation between combined oral contraceptives (COC) use and body weight in young women living in Poland. METHODS: Observational study on the group of young women on COC and the control group of young women who never used COC. Candidates for study (145 women) and control (218 women) groups were recruited in selected gynecological clinics in Poland during the period of 1-31 January 2002 (with the use of randomization). RESULTS: Both groups (study and control) were almost identical in age, anthropometric characteristics, number of pregnancies and deliveries. On the basis of this investigation it was found that there was no relation between use of COC and weight gain. Observed (in both groups) weight gain in young women was most probably related rather to time-passing (patients were getting older). The higher risk for overweight and obesity was found in the group of young women who had already had problems with overweight in their childhood. and in the group of women with high weight gain during the first pregnancy. CONCLUSION: COC use is not associated with weight gain in young women with a Central European life-style.  相似文献   
943.
PURPOSE: To provide a model for assessing occupational therapy workforce needs by using a demand-based approach to determine current workforce status in the Northwest region. Regional information may have implications for addressing national occupational therapy service needs. METHOD: A questionnaire was sent to a proportional random sample of 234 facilities that hire occupational therapy practitioners. Data were collected in July-August 2003 using structured mailing and follow-up procedures. RESULTS: Response rate was 79%. Twenty-four percent reported occupational therapy vacancies and 11% occupational therapy assistant vacancies; 48% predicted an increase in occupational therapy positions in the next 2 years and 41% an increase in occupational therapy assistant positions. Sixty-three percent of respondents reported difficulty in hiring. DISCUSSION: This study identifies an occupational therapy workforce shortage in the Northwest. Management of a shortage is critical, for even short-term adjustments could lead to permanent changes in service provision. This study demonstrates the importance of current information on the status of the national workforce and serves as a model for future studies.  相似文献   
944.
945.
946.
947.
948.
949.
950.
Forty-six (85%) basal cell and eight (15%) squamous cell carcinomas of the eyelids were treated with electron beams between 1963 and 1983. Lesion sizes ranged from microscopic to 4 cm, with 28 lesions larger than 1 cm. Thirty-eight lesions were treated with radiotherapy after incisional biopsy, and 16 were treated after excisional biopsy (specimens showed positive margins). Doses varied from 45 to 72 Gy, with daily fractions ranging from 2.12 to 4.0 Gy. There were six disease recurrences (10.9%): three in the treatment field and three at the treatment margin. Four of six recurrences were subsequently controlled by limited surgical excision and repair with preservation of the eye, whereas the other two required enucleation. Treatment sequelae such as skin atrophy, telangiectasis, and cosmetic results were evaluated in terms of radiotherapy parameters, pretreatment surgery, and size of the lesion. In 44 patients, the overall cosmetic result was judged as good to excellent, five patients had a mild to modest degree of deformity, and five had significant deformity. Such deformity was usually associated with tumor destruction or previous surgery. No major complications were noted.  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