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   3197篇
  免费   281篇
  国内免费   7篇
耳鼻咽喉   85篇
儿科学   101篇
妇产科学   51篇
基础医学   340篇
口腔科学   177篇
临床医学   451篇
内科学   691篇
皮肤病学   8篇
神经病学   381篇
特种医学   226篇
外科学   325篇
综合类   66篇
预防医学   253篇
眼科学   15篇
药学   185篇
肿瘤学   130篇
  2023年   22篇
  2021年   33篇
  2020年   25篇
  2019年   47篇
  2018年   67篇
  2017年   31篇
  2016年   57篇
  2015年   49篇
  2014年   88篇
  2013年   161篇
  2012年   137篇
  2011年   167篇
  2010年   103篇
  2009年   94篇
  2008年   146篇
  2007年   148篇
  2006年   147篇
  2005年   167篇
  2004年   121篇
  2003年   95篇
  2002年   101篇
  2001年   94篇
  2000年   110篇
  1999年   69篇
  1998年   46篇
  1997年   38篇
  1996年   43篇
  1995年   31篇
  1994年   27篇
  1993年   35篇
  1992年   64篇
  1991年   65篇
  1990年   69篇
  1989年   79篇
  1988年   85篇
  1987年   80篇
  1986年   64篇
  1985年   57篇
  1984年   50篇
  1983年   36篇
  1982年   29篇
  1980年   27篇
  1979年   23篇
  1978年   21篇
  1977年   19篇
  1976年   22篇
  1975年   18篇
  1974年   21篇
  1973年   23篇
  1972年   16篇
排序方式: 共有3485条查询结果,搜索用时 15 毫秒
71.
Background: Despite numerous studies examining the association between competitive sports participation and substance use behaviors among adolescents and young adults, the use of standardized measures to assess potential substance use disorders has been largely neglected. The objective of this study was to examine if past involvement in interscholastic sports (competitive school-sponsored sports) was associated with potential substance use disorders in young adulthood. Methods: Data for this study were taken from the Student Life Survey (SLS). A total of 3442 young adults participated in the SLS during the spring semester in 2013, with 74% of males and 71% of females indicating participation in interscholastic sport during high school. Results: Respondents who participated in interscholastic sports during high school had higher odds of positive screens for potential alcohol use disorders when compared with their peers who did not participate in interscholastic sports. No association was detected between interscholastic sports participation and potential drug abuse disorders. Moreover, previous involvement in certain types of sports was found to be associated with positive screens for potential alcohol use disorders (i.e., crew and football) and positive screens for potential drug abuse disorders (i.e., lacrosse) among the sample of young adults. Conclusions: School and community sport organizations should be aware of the potential link between sports participation and potential substance use disorders, and may consider brief substance use screeners during yearly physicals to monitor potential substance use problems among athletes.  相似文献   
72.
OBJECTIVES--To assess the compliance of invasive cardiologists in the United Kingdom with recently accepted national guidelines on the protection of health care workers and patients from hepatitis B. To determine levels of awareness of the infectivity and prevalence of the virus and current attitudes towards screening of patients before cardiac catheterisation and surgery. DESIGN--Anonymous postal survey by questionnaire from the University Hospital of Wales, Cardiff. The questionnaire established the respondent's position, knowledge of hepatitis B, current immunological state, and policy towards the routine screening of patients for hepatitis B carriage. PARTICIPANTS--All British cardiologists of consultant or senior registrar grade involved in invasive procedures. RESULTS--The response rate was 78% (211/271). 20% of respondents had never been vaccinated against hepatitis B and about a third of those vaccinated had not complied correctly with the recommended immunisation regimen. There was little uniformity in practices for screening patients for hepatitis B carriage before invasive procedures, and the level of knowledge concerning the prevalence of hepatitis B and the risks of inoculation was poor. CONCLUSIONS--Invasive cardiologists are at high risk of inoculation with hepatitis B. Nationally agreed guidelines are designed to protect both medical staff and patients against the risk of infection but currently they are ill heeded.  相似文献   
73.
74.

Objective

Research on patient involvement in decision-making in psychiatry has focused on first encounters. This study investigated what decisions are made, level of patient involvement and factors influencing patient involvement in ongoing outpatient visits.

Methods

72 visits conducted by 20 psychiatrists were video recorded. Patients had a diagnosis of depression or schizophrenia.

Results

On average, there was one medication related and one other decision per visit. Some psychiatrists involved patients more in decisions, as did female psychiatrists. Involvement was lower when patients had more negative symptoms.

Conclusion

Involvement in decision-making appears to be influenced by the individual psychiatrist and specific symptoms but not visit length.

Practice implications

It is noteworthy that patient involvement is not influenced by length of the visit given that this would be a barrier in busy clinical practice. The next step would be to identify the communication patterns of psychiatrists who involve patients more in decision-making.  相似文献   
75.
76.
77.
AIMS: We evaluated the TIMI Risk Score for Unstable Angina and Non-ST Elevation Myocardial Infarction for predicting clinical outcomes and the efficacy of tirofiban in non-ST elevation acute coronary syndromes. METHODS AND RESULTS: Developed in TIMI 11B, the risk score is calculated as the sum of seven presenting characteristics (age > or =65 years, > or =3 cardiac risk factors, documented coronary disease, recent severe angina, ST deviation > or =0.5 mm, elevated cardiac markers, prior aspirin use). The risk score was validated in the PRISM-PLUS database (n=1915) and tested for interaction with the efficacy of tirofiban+heparin vs heparin alone. The risk score revealed an increasing gradient of risk for death, myocardial infarction or recurrent ischaemia at 14 days ranging from 7.7-30.5% (P<0.001). Dichotomized at the median, patients with a score > or =4 derived a greater relative risk reduction with tirofiban (P((Interaction))=0.025). Among patients with normal creatine kinase myocardial bands, the risk score showed a 3.5-fold gradient of risk (P<0.001) and identified a population that derived significant benefit from tirofiban (RR 0.73, P=0.027). CONCLUSION: The TIMI Risk Score is a simple clinical tool for risk assessment that may aid in the early identification of patients who should be considered for treatment with potent antiplatelet therapy.  相似文献   
78.
To determine the significance of anginal chest pain during exercise testing, a series of 302 patients undergoing coronary arteriography with exercise testing was reviewed. Of the 302 patients, 85 had ischemic ECG changes and chest pain (Group I); 87 patients had ischemic ECG changes but no chest pain (Group II); 25 patients had chest pain but no ischemic ECG changes (Group III); 105 patients had neither chest pain nor ischemic ECG changes (Group IV). Coronary artery disease was present in 95 per cent of Group I, 75 per cent of Group II, 72 per cent of Group III, and 28 per cent of Group IV. Of those patients with coronary disease, multiple vessels were involved in 94 per cent of Group I, 51 per cent of Group II, 67 per cent of Group III, and 21 per cent of Group IV. The predictive value for presence and extent of coronary disease showed Group I > Groups II and III > Group IV (p < 0.025). We conclude that (1) anginal chest pain during exercise testing predicts the presence and extent of coronary disease more accurately than its absence; (2) the presence of chest pain even without an ischemic ECG response during exercise testing appears to be as predictive of coronary disease as an ischemic ECG response alone; and (3) the combination of anginal chest pain during exercise testing and an ischemic ECG response is highly predictive of multivessel coronary artery disease.  相似文献   
79.
Nausea and vomiting are common complaints in chronic alcoholics. Autonomic neuropathy and esophageal motor abnormalities are frequently observed in chronic alcoholics, but gastric emptying has not been studied in these patients. Gastric emptying of a solid meal was measured, using 99mTc-sulfur colloid cooked in a scrambled egg, in 10 male chronic alcoholics with upper gastrointestinal complaints of nausea and vomiting. All patients were adequately nourished, recently drinking, but just over withdrawal and free of clinical peripheral neuropathy. Gastric emptying in 10 alcoholics was similar to 5 normal controls (t 1/2 115 +/- 12 versus 107 +/- 8 min). These data suggest that upper gastrointestinal symptoms in chronic alcoholics are not related to gastric motor dysfunction.  相似文献   
80.
Kay  NE; Perri  RT 《Blood》1989,73(4):1016-1019
B-chronic lymphocytic leukemia (CLL) patients frequently suffer from moderate to severe hypogammaglobulinemia. This complication is a serious cause of morbidity and mortality in this disorder. There is recent evidence that natural killer (NK) cells modulate B-cell immunoglobin (Ig) synthesis/secretion. The authors therefore evaluated the circulating NK cells from B-CLL patients on their ability to regulate mitogen-induced B-cell Ig synthesis. Blood, NK cells (CD16+, CD3-) from three B-CLL patients with hypogammaglobulinemia were able to clearly down-regulate the pokeweed mitogen (PWM)-induced-B-cell Ig secretion. In contrast, CD16+, CD3- cells from age-sex-matched controls or B-CLL patients with normal Ig were either nonregulatory or enhanced mitogen-induced B-cell Ig secretion. An alternative explanation for hypogammaglobulinemia in B-CLL patients is the immunomodulation of B- cell Ig production/secretion by CD16+, CD3- blood cells.  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