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   153972篇
  免费   32701篇
  国内免费   2426篇
耳鼻咽喉   5230篇
儿科学   5466篇
妇产科学   2513篇
基础医学   3759篇
口腔科学   1577篇
临床医学   26960篇
内科学   48597篇
皮肤病学   7530篇
神经病学   15064篇
特种医学   6422篇
外科学   41264篇
综合类   257篇
现状与发展   72篇
预防医学   7463篇
眼科学   3446篇
药学   1356篇
中国医学   41篇
肿瘤学   12082篇
  2024年   689篇
  2023年   4821篇
  2022年   1276篇
  2021年   3230篇
  2020年   6101篇
  2019年   2282篇
  2018年   7523篇
  2017年   7412篇
  2016年   8488篇
  2015年   8525篇
  2014年   15628篇
  2013年   15773篇
  2012年   5789篇
  2011年   5797篇
  2010年   10531篇
  2009年   14386篇
  2008年   6088篇
  2007年   4268篇
  2006年   6749篇
  2005年   3988篇
  2004年   3209篇
  2003年   2200篇
  2002年   2290篇
  2001年   3859篇
  2000年   3075篇
  1999年   3291篇
  1998年   3687篇
  1997年   3500篇
  1996年   3399篇
  1995年   3244篇
  1994年   1974篇
  1993年   1581篇
  1992年   1422篇
  1991年   1451篇
  1990年   1105篇
  1989年   1208篇
  1988年   1051篇
  1987年   866篇
  1986年   899篇
  1985年   744篇
  1984年   554篇
  1983年   532篇
  1982年   519篇
  1981年   405篇
  1980年   366篇
  1979年   312篇
  1978年   337篇
  1977年   400篇
  1975年   286篇
  1972年   306篇
排序方式: 共有10000条查询结果,搜索用时 16 毫秒
991.
992.
993.
994.
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   
995.
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   
996.
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   
997.
998.
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   
999.
1000.
Identification of Alcohol Abuse and Alcoholism with Biological Parameters   总被引:3,自引:0,他引:3  
The prevalence and incidence of heavy alcohol consumption are major problems which have been increasing in many countries in recent years. It is crucial for physicians to consistently identify early drinking problems as well as the various end disease states in order to minimize suffering and maximize recovery. This paper reviews the evolutionary development of clinical tools for detection of alcohol abuse. The focus is primarily on clinical/biochemical indicators of alcohol abuse, emphasizing but not limited to changes in hematological characteristics, liver enzyme activity, lipids, immune function factors, hormones, neurological factors, and some physically based tests. Use of test combinations and sophisticated statistical analysis of pattern changes in test batteries evidence increased diagnostic efficiency.  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