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   3556篇
  免费   232篇
  国内免费   11篇
耳鼻咽喉   30篇
儿科学   163篇
妇产科学   66篇
基础医学   410篇
口腔科学   29篇
临床医学   281篇
内科学   850篇
皮肤病学   37篇
神经病学   208篇
特种医学   140篇
外科学   450篇
综合类   54篇
一般理论   1篇
预防医学   310篇
眼科学   152篇
药学   351篇
中国医学   7篇
肿瘤学   260篇
  2023年   18篇
  2022年   47篇
  2021年   116篇
  2020年   54篇
  2019年   86篇
  2018年   104篇
  2017年   59篇
  2016年   90篇
  2015年   81篇
  2014年   153篇
  2013年   216篇
  2012年   297篇
  2011年   271篇
  2010年   148篇
  2009年   138篇
  2008年   196篇
  2007年   182篇
  2006年   185篇
  2005年   171篇
  2004年   145篇
  2003年   118篇
  2002年   112篇
  2001年   62篇
  2000年   49篇
  1999年   35篇
  1998年   17篇
  1997年   20篇
  1996年   15篇
  1993年   17篇
  1992年   30篇
  1991年   37篇
  1990年   41篇
  1989年   27篇
  1988年   25篇
  1987年   25篇
  1986年   34篇
  1985年   30篇
  1984年   34篇
  1983年   29篇
  1982年   21篇
  1981年   25篇
  1980年   14篇
  1979年   16篇
  1978年   24篇
  1977年   20篇
  1976年   24篇
  1975年   17篇
  1974年   18篇
  1973年   15篇
  1972年   13篇
排序方式: 共有3799条查询结果,搜索用时 9 毫秒
1.
Purpose:Since the declaration of the lockdown due to COVID-19, the usage of digital devices has gone up across the globe, resulting in a challenge for the visual systems of all ages. The purpose of this study is to assess the impact of the lockdown on digital device usage, and consequently, the ocular surface health implications and circadian rhythm abnormalities related to digital eye strain.Methods:An open online survey was sent through various social media platforms and was open for a period of 2 weeks.Results:A total of 407 usable responses were obtained; the average age of respondents was 27.4 years. Typically, 93.6% of respondents reported an increase in their screen time since the lockdown was declared. The average increase in digital device usage was calculated at about 4.8 ± 2.8 h per day. The total usage per day was found to be 8.65 ± 3.74 hours. Sleep disturbances have been reported by 62.4% of people. Typically, 95.8% of respondents had experienced at least one symptom related to digital device usage, and 56.5% said that the frequency and intensity of these symptoms increased since the lockdown was declared.Conclusion:The study highlighted the drastic increase in use of digital devices after the initiation of the COVID-19 lockdown, and along with it, the slow deterioration of ocular health across all age groups. Awareness about prevention of digital eye strain should be stressed, and going forward, measures to bring these adverse effects to a minimum should be explored.  相似文献   
2.
3.
4.
Ectopic prolactin secretion from a gonadoblastoma   总被引:1,自引:0,他引:1  
W H Hoffman  R R Gala  K Kovacs  M G Subramanian 《Cancer》1987,60(11):2690-2695
A 6.5-year-old girl developed isosexual, pseudoprecocious puberty secondary to a gonadoblastoma. The tumor was found to produce and secrete both immunoassayable and bioassayable prolactin based on immunohistochemical techniques and the presence of a prolactin gradient between the tumor vein and peripheral vein. The source of the prolactin was a Sertoli-like cell. Neither growth hormone nor growth hormone-releasing hormone was detected within the tumor. This case confirms the ectopic production of prolactin by neoplastic tissue.  相似文献   
5.
We hypothesized that increased ambient concentrations of metals, as a consequence of escalating urbanization and industrialization of the Gulf region will respond in increased contamination of edible fish species. In this study, we report concentrations of chromium, manganese, cobalt, copper, zinc, arsenic, cadmium, mercury and lead in meat and liver of wild Red-spot emperor (Lethrinus lentjan) from three sampling points at the UAE coast. Analysis was performed by the ICP-MS/microwave digestion. Our study has shown that meat and liver metal content was significantly higher in areas with higher industrial activity, although metal values did not exceed permitted levels of fish for human consumption.  相似文献   
6.
Laparoscopic cholecystectomy for left-sided gallbladder (sinistroposition).   总被引:1,自引:0,他引:1  
Transposition of the gallbladder to the left side without situs inversus viscerum is rare. These gallbladders are situated under the left lobe of the liver between Segment III and IV or on Segment III to the left of the falciform ligament. Because routine preoperative studies may not detect the anomaly, it may provide the surgeons with an unusual surprise during laparoscopy. Awareness of the unpredictable confluence of the cystic duct into the common bile duct and selective use of intraoperative cholangiography aid in the safe laparoscopic management of this unusual problem.  相似文献   
7.
8.
9.
10.
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