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   906篇
  免费   45篇
  国内免费   6篇
儿科学   12篇
妇产科学   14篇
基础医学   101篇
口腔科学   44篇
临床医学   111篇
内科学   180篇
皮肤病学   39篇
神经病学   90篇
特种医学   13篇
外科学   143篇
综合类   6篇
预防医学   39篇
眼科学   21篇
药学   74篇
肿瘤学   70篇
  2023年   11篇
  2022年   8篇
  2021年   10篇
  2020年   17篇
  2019年   18篇
  2018年   17篇
  2017年   12篇
  2016年   29篇
  2015年   19篇
  2014年   30篇
  2013年   41篇
  2012年   59篇
  2011年   57篇
  2010年   31篇
  2009年   29篇
  2008年   50篇
  2007年   48篇
  2006年   50篇
  2005年   49篇
  2004年   44篇
  2003年   36篇
  2002年   39篇
  2001年   27篇
  2000年   23篇
  1999年   19篇
  1998年   15篇
  1997年   9篇
  1996年   14篇
  1995年   10篇
  1994年   4篇
  1993年   6篇
  1992年   9篇
  1991年   11篇
  1990年   6篇
  1989年   8篇
  1988年   8篇
  1987年   3篇
  1986年   7篇
  1985年   7篇
  1984年   9篇
  1983年   12篇
  1982年   5篇
  1980年   4篇
  1977年   3篇
  1976年   6篇
  1975年   3篇
  1974年   3篇
  1946年   2篇
  1943年   2篇
  1935年   3篇
排序方式: 共有957条查询结果,搜索用时 15 毫秒
101.
A longitudinal population study of a total of 1462 women aged 38-60 was carried out in 1968-69 in Gothenburg, Sweden. The women have been re-studied in 1974-75 and 1980-81. The incidences of myocardial infarction during the following 12-year period were: three of 29 women with a history of angina pectoris (10%), four of 23 women with initial ECG changes at rest (17%) and one of 30 with ECG changes during work (3%). In addition, all women of similar age in Gothenburg with myocardial infarction during the years 1968-70 have been followed-up with respect to mortality, and in all there were 47 women who were alive on arrival at hospital. The figures for the 12-year overall mortality in the population study were: three women with angina pectoris (10%), four women with ECG changes at rest (17%) and three women with ECG changes during work (10%) and in the series of women with myocardial infarction 21 of 47 (45%). It seemed that the mortality among women with a history of angina pectoris or ECG changes at rest or during exercise indicating ischaemic heart disease was only slightly increased, if at all, compared to other women in the population, while having had a myocardial infarction significantly increased the mortality risk.  相似文献   
102.
103.
The regulation of the specific activities of adenylate kinase (EC 2.7.4.3) and creatine kinase (EC 2.7.3.2) in myogenic cell lines is independent of cell fusion. The observed increases in enzyme specific activities are cell density dependent, and may be further broken down into contributions from an increase in enzyme activity per cell and a decrease in protein per cell. Only the former appears to be affected by medium conditioning.  相似文献   
104.
Mannan-binding lectin (MBL) is a member of the innate immune system, and MBL-deficiency affects 10-15% of Caucasians. With development of a plasma-derived MBL, substitution has become a therapeutic option in diseases associated with MBL insufficiency. The pharmacokinetics of injected MBL is weakly described, particularly in patients with infectious diseases. The pharmacokinetic profile of MBL following administration of 0.08 mg/kg to 20 healthy MBL-deficient volunteers and 0.2 mg/kg to 2 patients with Staphylococcus aureus septicaemia was established. In the volunteers, the maximal concentration was 2849 microg/l; the mean half-life (T(1/2)) was 69.6 h (14.6-114.9 h). The normalized clearance was 9x10(-6) l/minxkg, and the mean residence time was 82 h. In the patients the serum-MBL versus time curves were similar to those in the volunteers, and T(1/2) values were 36 and 40 h. In conclusion, MBL is distributed into a median volume of 3.4 l similar to the plasma volume, and the elimination in septicaemic patients was within the range of the controls. Due to the large individual variation in T(1/2), we recommend that MBL therapy, with respect to dose and infusion intervals, is based on the chosen therapeutic target (> or =1000 microg/l) and MBL serum determinations following the first infusion.  相似文献   
105.
106.
In a cross-sectional study we investigated the relationship between muscle and bone parameters in the mid-thigh in older people using data from a single axial computed tomographic section through the mid-thigh. Additionally, we studied the association of these variables with incident low-trauma lower limb fractures. A total of 3,762 older individuals (1,838 men and 1,924 women), aged 66–96 years, participants in the AGES-Reykjavik study, were studied. The total cross-sectional muscular area and knee extensor strength declined with age similarly in both sexes. Muscle parameters correlated most strongly with cortical area and total shaft area (adjusted for age, height, and weight) but explained <10 % of variability in those bone parameters. The increment in medullary area (MA) and buckling ratio (BR) with age was almost fourfold greater in women than men. The association between MA and muscle parameters was nonsignificant. During a median follow-up of 5.3 years, 113 women and 66 men sustained incident lower limb fractures. Small muscular area, low knee extensor strength, large MA, low cortical thickness, and high BR were significantly associated with fractures in both sexes. Our results show that bone and muscle loss proceed at different rates and with different gender patterns.  相似文献   
107.
Fabry's disease is a rare but important cause of structural cardiac disease that may influence cardiac surgical decision making. Herein we present a case of mitral valve repair in a patient with Fabry's disease and review the cardiac-related literature on this lysosomal storage disease.  相似文献   
108.
109.
Objective. To analyse drug use in early pregnancy with special focus on socio-demographic factors associated with psychotropic and analgesic drug use. Design. Cross-sectional study. Setting and subjects. A total of 1765 women were invited via their local health care centres, and 1111 participated at 11–16 weeks of pregnancy by filling out a postal questionnaire concerning socio-demographic and obstetric background, stressful life events, and drug use. Main outcome measures. Drug use prior to and early on in pregnancy, socio-demographic factors, smoking, and adverse life events were investigated. Drug categories screened for were psychotropics (collective term for antidepressants, relaxants, and sleep medication), analgesics, hormones, nicotine, vitamins/minerals, and homeopathic medicine. Results. Drug use from the aforementioned drug categories, excluding vitamins/minerals and homeopathic medicine, was reduced by 18% during early pregnancy, compared with six months prior to conception (49% vs. 60%). Psychotropic drug use during early pregnancy was associated with elementary maternal education (p < 0.5), being unemployed (p < 0.001), being single/divorced/separated (p < 0.01), smoking prior to or during pregnancy (p < 0.01), forced to change job/move house (p < 0.001), and psychotropic drug use six months prior to pregnancy (p < 0.001). No items on the stressful life events scale were associated with increased analgesic use, which increased only with multiparity. Conclusions. Use of analgesics and psychotropic drugs seems common in pregnancy. Our results indicate that lack of a support network, stressful life events, and lower status in society may predispose women to more drug use. GPs and midwives responsible for maternity care could take this into account when evaluating risk and gain for women and foetuses in the primary care setting.Key Words: Childbirth and health, drug use, general practice, Iceland, maternity care, pregnancy, primary health care, psychotropic drugsPregnant women are usually excluded from drug trials for ethical reasons.This study showed that:
  • Almost half of the women were taking at least one drug during early pregnancy, excluding vitamins/minerals and homeopathic medicine.
  • Significantly fewer women used drugs during early pregnancy, and those who did used drugs from fewer drug categories than compared with six months prior to pregnancy.
  • Drug use during early pregnancy had the strongest correlation with drug use six months prior to pregnancy.
  • Drug use during early pregnancy was associated with adverse life events and lower social position.
  相似文献   
110.
Objective. To study the prevalence and possible predictors for smoking during pregnancy in Iceland. Design. A cross-sectional study. Setting. Twenty-six primary health care centres in Iceland 2009–2010. Subjects. Women attending antenatal care in the 11th–16th week of pregnancy were invited to participate by convenient consecutive manner, stratified according to residency. A total of 1111 women provided data in this first phase of the cohort study. Main outcome measures. Smoking habits before and during early pregnancy were assessed with a postal questionnaire, which also included questions about socio-demographic background, physical and emotional well-being, and use of medications. Results. The prevalence of smoking prior to pregnancy was 20% (223/1111). During early pregnancy, it was 5% (53/1111). In comparison with women who stopped smoking during early pregnancy, those who continued to smoke had on average a significantly lower level of education, had smoked more cigarettes per day before pregnancy, and were more likely to use nicotine replacement therapy in addition to smoking during pregnancy. A higher number of cigarettes consumed per day before pregnancy and a lower level of education were the strongest predictors for continued smoking during pregnancy. Conclusion. The majority of Icelandic women who smoke stop when they become pregnant, and the prevalence of smoking during pregnancy in Iceland is still about 5%. Our results indicate stronger nicotine dependence in women who do not stop smoking during pregnancy. Awareness of this can help general practitioners (GPs) and others providing antenatal care to approach these women with more insight and empathy, which might theoretically help them to quit.Key Words: Antenatal care, childbirth and health, general practice, Iceland, pregnancy, primary health care, smoking habitsSmoking during pregnancy is a major preventable risk factor for foetal and neonatal morbidity and mortality.
  • This study shows that the prevalence of smoking during early pregnancy in Iceland is 5%.
  • A history of heavy smoking before pregnancy and low level of education characterize the women who do not stop smoking early in pregnancy.
  • Our results can help GPs and midwives to identify women at risk of continued smoking during pregnancy and possibly assist them to quit.
  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