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   247篇
  免费   3篇
耳鼻咽喉   1篇
儿科学   11篇
妇产科学   16篇
基础医学   10篇
口腔科学   14篇
临床医学   12篇
内科学   52篇
神经病学   10篇
特种医学   10篇
外科学   90篇
预防医学   11篇
药学   11篇
肿瘤学   2篇
  2021年   3篇
  2020年   1篇
  2019年   26篇
  2018年   16篇
  2017年   6篇
  2016年   1篇
  2015年   1篇
  2014年   4篇
  2013年   3篇
  2012年   1篇
  2011年   2篇
  2010年   1篇
  2007年   1篇
  1985年   13篇
  1984年   26篇
  1983年   15篇
  1982年   19篇
  1981年   13篇
  1980年   15篇
  1979年   17篇
  1978年   16篇
  1977年   3篇
  1976年   13篇
  1975年   11篇
  1974年   18篇
  1973年   5篇
排序方式: 共有250条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Women commonly present to the emergency room with subacute or acute symptoms of gynecologic origin. Although a pelvic exam and ultrasound (US) are the preferred initial diagnostic tools for gynecologic entities, a CT is often the first line imaging modality in the emergency department. We will provide a review of normal uterine enhancement and normal pregnancy related findings, and then familiarize radiologists with the CT appearances of gynecologic entities classically described on ultrasound that may present to the emergency department.  相似文献   
5.
6.
7.
We found that 14.3% (15/105) of Amblyomma maculatum and 3.3% (10/299) of Dermacentor variabilis ticks collected at 3 high-use military training sites in west-central Kentucky and northern Tennessee, USA, were infected with Rickettsia parkeri and Rickettsia montanensis, respectively. These findings warrant regional increased public health awareness for rickettsial pathogens and disease.  相似文献   
8.
Many of the substances known to control the secretion of pituitary gonadotropins also modulate the secretion of human chorionic gonadotropin (hCG) by the placenta. In order to study the effect of estrogens and progestins on hCG secretion, term placental explants were cultured in culture media for 144 hours. During the culture period, hCG secretion increased after 48 hours, and a fortyfold increase was observed after 144 hours (p less than 0.001). Compared to concentrations of hCG in control cultures, secretion of hCG was markedly suppressed in the presence of progesterone 2.25 X 10(-5)M (p less than 0.001), a concentration similar to that found in term placental tissue (1.7 +/- 0.2 micrograms/gm of tissue). Suppression of hCG by progesterone occurred in a dose-response manner (r = -0.9100, p less than 0.01). Estradiol, an important steroid modulator of pituitary gonadotropins, did not significantly suppress the secretion of hCG, except in pharmacologic concentrations (10(-4)M), and physiologic concentrations of estradiol had no effect on the suppression of hCG by progesterone. These results suggest that the mechanism by which progesterone suppresses the secretion of hCG differs from the manner in which steroids modulate the secretion of pituitary gonadotropins.  相似文献   
9.
10.
Irrigation of the stomach with saline containing levarterenol has only a small additive effect on the reduction of gastric blood flow, regardless of the temperature of the saline.  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