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   152902篇
  免费   32748篇
  国内免费   2425篇
耳鼻咽喉   5184篇
儿科学   5519篇
妇产科学   2536篇
基础医学   3694篇
口腔科学   1606篇
临床医学   26911篇
内科学   48094篇
皮肤病学   7472篇
神经病学   15042篇
特种医学   6426篇
外科学   41408篇
综合类   282篇
现状与发展   72篇
一般理论   2篇
预防医学   7422篇
眼科学   3381篇
药学   1142篇
中国医学   56篇
肿瘤学   11826篇
  2024年   514篇
  2023年   4797篇
  2022年   1224篇
  2021年   3198篇
  2020年   6099篇
  2019年   2279篇
  2018年   7486篇
  2017年   7437篇
  2016年   8482篇
  2015年   8482篇
  2014年   15593篇
  2013年   15772篇
  2012年   5658篇
  2011年   5681篇
  2010年   10452篇
  2009年   14346篇
  2008年   5940篇
  2007年   4183篇
  2006年   6669篇
  2005年   3914篇
  2004年   3154篇
  2003年   2122篇
  2002年   2168篇
  2001年   3889篇
  2000年   3122篇
  1999年   3306篇
  1998年   3672篇
  1997年   3484篇
  1996年   3380篇
  1995年   3225篇
  1994年   1955篇
  1993年   1590篇
  1992年   1452篇
  1991年   1462篇
  1990年   1112篇
  1989年   1230篇
  1988年   1063篇
  1987年   905篇
  1986年   920篇
  1985年   759篇
  1984年   581篇
  1983年   565篇
  1982年   535篇
  1981年   421篇
  1980年   374篇
  1979年   333篇
  1978年   347篇
  1977年   409篇
  1975年   289篇
  1972年   314篇
排序方式: 共有10000条查询结果,搜索用时 140 毫秒
991.
992.
BACKGROUND: A venous lake is a venous ectasia that appears mostly on the lower lip and other sun-exposed areas of an older person. Treatment of lip venous lake includes surgical excision, laser therapy, infrared coagulation, and cryotherapy. Although the use of sclerotherapy on varicose veins, leg telangiectasia, hemorrhoids, and hemangiomas is well established, the use of sclerotherapy for lip venous lake has not been reported. OBJECTIVE: We present two cases of lip venous lake treated with intralesional injection of 1% polidocanol. METHOD: Two cases are reported, and literature is reviewed. RESULT: The lesions virtually disappeared, leaving an inconspicuous scar, with two sessions of sclerotherapy. Side effects were not observed. CONCLUSION: Sclerotherapy with polidocanol is effective in the treatment of lip venous lake and offers an alternative to conventional methods.  相似文献   
993.
994.
995.
996.
OBJECTIVES: Studies of emergency department (ED) pain management in patients with trauma have been mostly restricted to patients with fractures, yet the potential for undertreatment of more severely injured patients is great. The authors sought to identify factors associated with failure to receive ED opioid administration in patients with acute trauma who subsequently required hospitalization. METHODS: At an urban Level 1 trauma center and teaching hospital, a retrospective cohort study of trauma team activation patients requiring hospitalization between January 1 and December 31, 1999, was conducted. The authors excluded patients receiving opioids only within ten minutes of chest tube insertion or fracture manipulation. The main outcome measure was ED opioid administration. RESULTS: A total of 540 charts of hospitalized first-tier trauma team activation patients were reviewed. A total of 258 (47.8%) received intravenous opioid analgesia within three hours of ED arrival. The median time to receiving the first dose of opioids was 95 minutes. Patients were independently less likely to receive opioids if they were younger or older, were intubated, had a lower Revised Trauma Score, or did not require fracture manipulation. Patients with these factors were less likely to receive opioids independent of the amount of time they spent in the ED. CONCLUSIONS: Many trauma activation patients requiring hospitalization do not receive opioid analgesia in the ED. Patients at particular risk for oligoanalgesia include those who are younger or older and those who are more seriously injured, as defined by a lower Revised Trauma Score, lower Glasgow Coma Scale score, and intubation.  相似文献   
997.
BACKGROUND: A common problem facing patients suffering from psoriasis is the need for surgery that requires incision through active psoriatic skin. Many patients have been denied surgery because of the fear of an increased risk of infection, decreased wound healing ability, and worsening of the psoriatic lesions. OBJECTIVE: To assess the practices and beliefs of dermatologists and surgeons (orthopedic and plastic surgeons) faced with the decision of whether to operate through active psoriatic skin. METHODS: Dermatologists, orthopedic surgeons, and plastic surgeons selected from various professional membership lists from five representative cities were sent a survey to ascertain their opinions on operating on active psoriatic skin. Psoriatic patients were also given forms asking about the severity of their psoriasis and whether they had ever been denied surgery. RESULTS: Dermatologists are more likely to condone surgery in active psoriatic skin and to believe that there is not a risk of increased infection or decreased wound healing than are orthopedic surgeons and plastic surgeons. These findings are statistically significant (P<0.05). CONCLUSION: With proper preoperative measures and dermatologic treatment, surgery can be performed on active psoriatic skin in most cases with minimal reservations, although a controlled, prospective study is necessary to arrive at a definitive conclusion.  相似文献   
998.
The purpose was to investigate experienced loneliness among the elderly. The material included 1725 people, aged 75 and over. The study describes relationships between loneliness, social network, cognitive function and health. Thirty-five per cent experienced loneliness, and a higher percentage was found among women. A gradual increase in loneliness was found up to the age of 90, after which a levelling was found. Elderly persons living together with a partner experienced less loneliness. There were no significant differences between those with and without children. Ten per cent reported not having any friends and, of these, one out of two experienced loneliness. A high frequency of experienced loneliness was found among elderly people with reduced cognitive function. Subjectively experienced bad health and loneliness were strongly related to each other, i.e. a person who experienced loneliness did usually not feel completely healthy.  相似文献   
999.
1000.
The influence of experimentally induced hepatic dysfunction on the pharmacokinetics of Cyclosporine A (CsA) was determined in dogs. The pharmacokinetics of oral (PO) and intravenous (IV) CsA were studied before and after 70 per cent hepatectomy or complete bile duct ligation (CBDL). Changes in liver function were monitored by serial measurements of serum bilirubin, and by the maximum removal rate (Rmax) and plasma disappearance rate (ICG-K) of indocyanine green (ICG). Concentrations of CsA in whole blood were measured by HPLC. Seventy per cent hepatectomy caused significant liver dysfunction: the ICG-Rmax decreased by 47.7±7.1 per cent (mean±SD) and the ICG-K decreased by 61.3±9.7 per cent during the first week after hepatectomy. At the same time, the systemic clearance (CLs) of IV-CsA decreased by 43.9±8.2 per cent, the area under the concentration curve (AUC) of IV-CsA increased by 35.4±20.8 per cent and the bioavailability of CsA decreased by 26.4±14.8 per cent. CBDL also induced significant liver dysfunction: the ICG-Rmax decreased by 39.1±12.8 per cent and the ICG-K decreased by 65.6±3.6 per cent in the second week after the operation. During the same period, the AUC of PO-CsA decreased by 69.9±10.7 per cent and the bioavailability of CsA also decreased markedly by 73.9±15.6 per cent. These data indicate that hepatic impairment significantly influences the pharmacokinetics of CsA, not only by the changes in intestinal absorption, but also by those in hepatic, metabolism. Dose adjustment is therefore necessary in the presence of hepatic dysfunction in order to maintain an adequate blood concentration of CsA without causing side effects. This research was performed in the Department of Surgery, University of Pittsburgh Health Center, University of Pittsburgh, USA  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