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   14513篇
  免费   1862篇
  国内免费   155篇
耳鼻咽喉   46篇
儿科学   578篇
妇产科学   843篇
基础医学   606篇
口腔科学   74篇
临床医学   1136篇
内科学   4631篇
皮肤病学   59篇
神经病学   722篇
特种医学   95篇
外国民族医学   1篇
外科学   2221篇
综合类   800篇
一般理论   1篇
预防医学   2737篇
眼科学   27篇
药学   465篇
中国医学   30篇
肿瘤学   1458篇
  2024年   22篇
  2023年   432篇
  2022年   302篇
  2021年   1072篇
  2020年   824篇
  2019年   859篇
  2018年   802篇
  2017年   676篇
  2016年   700篇
  2015年   667篇
  2014年   972篇
  2013年   1254篇
  2012年   632篇
  2011年   714篇
  2010年   524篇
  2009年   593篇
  2008年   630篇
  2007年   605篇
  2006年   579篇
  2005年   444篇
  2004年   423篇
  2003年   343篇
  2002年   287篇
  2001年   247篇
  2000年   182篇
  1999年   165篇
  1998年   165篇
  1997年   156篇
  1996年   142篇
  1995年   125篇
  1994年   117篇
  1993年   112篇
  1992年   99篇
  1991年   77篇
  1990年   72篇
  1989年   60篇
  1988年   71篇
  1987年   55篇
  1986年   71篇
  1985年   64篇
  1984年   50篇
  1983年   32篇
  1982年   27篇
  1981年   17篇
  1980年   9篇
  1979年   18篇
  1978年   10篇
  1976年   7篇
  1974年   5篇
  1971年   4篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
91.
Evidence gathered from 1997 to 2006 indicates progress in reducing maternal mortality in Nepal, but public health services are still constrained by resource and staff shortages, especially in rural areas. The five-year Support to the Safe Motherhood Programme builds on the experience of the Nepal Safer Motherhood Project (1997-2004). It is working with the Government of Nepal to build capacity to institute a minimum package of essential maternity services, linking evidence-based policy development with health system strengthening. It has supported long-term planning, working towards skilled attendance at every birth, safe blood supplies, staff training, building management capacity, improving monitoring systems and use of process indicators, promoting dialogue between women and providers on quality of care, and increasing equity and access at district level. An incentives scheme finances transport costs to a health facility for all pregnant women and incentives to health workers attending deliveries, with free services and subsidies to facilities in the poorest 25 districts. Despite bureaucracy, frequent transfer of key government staff and political instability, there has been progress in policy development, and public health sector expenditure has increased. For the future, a human resources strategy with career paths that encourage skilled staff to stay in the government service is key.  相似文献   
92.
OBJECTIVES: Percentage of deliveries assisted by a skilled birth attendant (SBA) has become a proxy indicator for reducing maternal mortality in developing countries, but there is little data on SBA competence. Our objective was to evaluate the competence of health professionals who typically attend hospital and clinic-based births in Benin, Ecuador, Jamaica, and Rwanda. Methods: We measured competence against World Health Organization's (WHO) Integrated Management of Pregnancy and Childbirth guidelines. To evaluate knowledge, we used a 49-question multiple-choice test covering seven clinical areas. To evaluate skill, we had participants perform five different procedures on anatomical models. The 166 participants came from facilities at all levels of care in their respective countries. Results: On average, providers answered 55.8% of the knowledge questions correctly and performed 48.2% of the skills steps correctly. Scores differed somewhat by country, provider type, and subtopic. Conclusion: A wide gap exists between current evidence-based standards and current levels of provider competence.  相似文献   
93.
To evaluate whether insecticide-treated netting (ITN) reduces child mortality in different epidemiological settings, 4 large, randomized, controlled trials were conducted in Africa. Here we report the findings from the trial in Burkina Faso, in an area of hyperendemic and markedly seasonal malaria transmission. The trial involved 158 villages, with a total population of some 90,000, grouped into 16 geographical clusters. Ascertainment of mortality among children aged 6–59 months began in early 1993. In June/July 1994, 8 of the clusters, randomly selected, received permethrin-treated curtains. Follow-up of children and ascertainment of mortality continued until May 1996. A 15% reduction in all-cause mortality among children aged 6–59 months was observed over the 2-year period following the installation of the curtains (95% c.i. – 4% to 30%). In the first year, post-intervention mortality was substantially lower in the clusters receiving curtains compared with the control clusters (rate ratio = 0.74; 95% c.i. 0.57, 0.95) but in the second year, there was no difference between mortality in the two groups (rate ratio = 0.99). The overall two-year impact of the intervention is consistent with the impacts observed in other trials which have demonstrated reductions in child mortality of from 17% to 33%. However, the year-by-year analysis raises some concerns about the long-term effect of ITN. Further follow-up of this population is warranted.  相似文献   
94.
目的探究感染性休克治疗的前3天患者的液体平衡状态与预后的关系。方法采用回顾性对照研究。查看1999年1月至2003年12月收入首都医科大学附属复兴医院ICU的感染性休克患者病例记录,入选病例必须严格符合感染性休克的诊断标准,且既往无肾功能不全病史。采集病例相关数据以及诊断后第1、2、3天的液体平衡值。比较不同组别患者的急性生理和慢性健康评分(APACHEⅡ)、继发器官衰竭评分(SOFA)、液体平衡和病死率等数据。对影响患者预后的独立危险因素进行Logistic回归分析,确定和描述感染性休克患者的预后与在前3天的液体复苏治疗中出现的负平衡((0mL)相关因素的关系。结果负液体平衡患者与未出现负液体平衡患者2组的病死率差异有统计学意义(52.4%vs87.5%,χ2=5.303,P=0.021)。通过对入组时患者年龄、APACHEⅡ评分、第1天和第3天SOFA评分和正负平衡等影响患者预后的独立危险因素Logistic回归分析,表明前3天的治疗中,若有1d出现负液体平衡即可成为影响患者预后的独立危险因素(P=0.035)。结论在感染性休克前3天的治疗中,若有1d出现液体平衡负值即可成为影响感染性休克患者预后的独立因素,对感染性休克的28d生存预后有较强的预测性。在前3天的治疗中出现液体平衡为负值((0mL)的感染性休克患者的生存率比液体平衡为正值的患者的28d生存率高。  相似文献   
95.
Background Prostate cancer is rare in Asia, but the number of patients is increasing in Japan. We conducted an epidemiological study of prostate cancer in Gunma Prefecture, Japan, to investigate the trends and characteristics of the disease.
Methods: The subjects were 1.411 prostate cancer patients newly diagnosed between 1985 and and 656 patients who died from prostate cancer between 1981 and 1992. The incidence and mortality rates were calculated by year, demographic region and age.
Results: The yearly incidence rate showed an increase but the mortality rate showed no marked fluctuations. There was no significant difference between urban and ruraI districts in either incidence or mortality rate. The incidence rate tended to be high in the northern part of the prefecture, but no marked variation in mortality rate was seen. The incidence and mortality rates in districts with a history of manganese mining were high compared to those in districts without mining. In contrast, the incidence and mortality rates in districts with a history of zinc mining were comparatively lower. Both incidence and mortality rates showed a marked increase with age. The age-specific incidence showed a double logarithmic relationship to age.
Conclusions: The increase of the yearly incidence rate might be due to changes in lifestyle and environmental factors, improved diagnostic techniques, and increased awareness among the general public regarding prostate disease. Further investigation is needed to clarify the pattern and the causes of regional differences in the incidence and mortality rates. The possibilities that manganese and zinc might be related to prostatic carcinogenesis are suggested. Int J Urol 1995:2:191–197  相似文献   
96.
目的观察早期服用开博通治疗急性心肌梗塞的近期效果。资料与方法201例急性心肌梗塞症状后24小时内入院且无明显低血压患者,自入院开始后在接受常规治疗基础上,128例加服开博通(治疗组),60例加服安慰剂(对照组),均治疗4周。结果治疗组中前壁梗塞患者的室性心律失常、心力衰竭、梗塞延展发生率、4周病死率以及1年院外猝死率均低于对照组前壁梗塞患者,而下壁梗塞患者无此差异;治疗组中下壁梗塞患者并发房室传导阻滞者高于对照组下壁梗塞患者,而前壁梗塞患者无此差异。结论开博通能降低前壁梗塞患者的住院期重要并发症及早期病死率,且能降低1年院外猝死率。  相似文献   
97.
A total of 219 inpatients with a DSM-III diagnosis of major depression, 150 women and 69 men, were followed prospectively for 3–10 years and mortality was recorded. The patients were previous participants in psychopharmacological multicenter trials, which were carried out for the purpose of comparing the antidepressant effect of newer 5-HT reuptake inhibitors with that of the tricyclic antidepressant drug, clomipramine. The study comprised patients with a total Hamilton Rating Scale for Depression score of ≥ 18 and/or a Hamilton subscale score of ≥ 9. Diagnostic classification according to the Newcastle I Scale in endogenous and nonendogenous depression was performed. The observed mortality was significantly greater than that expected. The increased mortality was essentially due to suicides and mainly found among women. Patients scored as nonendogenously depressed had a significantly higher suicide rate than endogenously depressed patients. The excess number of suicides in the nonendogenous group largely occurred within the first year of observation. No association was found between response to the antidepressant treatment in the trial and the suicide risk in the first 3 years of observation.  相似文献   
98.
背景 心血管代谢性危险因素聚集(CRFC)是老年人常见的健康问题,目前相关研究主要集中在流行病学分布特征的描述,有关CRFC与人群全因死亡风险的研究鲜有报道。目的 探讨CRFC与社区≥55岁人群全因死亡风险的关系,为开展≥55岁人群社区保健提供参考。方法 于2011年9—11月采用典型抽样法选取宁夏回族自治区吴忠市和银川市5个社区的1 046名≥55岁人群作为研究对象,对其开展一般情况问卷调查、体格检查、超声检查、实验室检查和CRFC评价[纳入中心性肥胖、高胆固醇血症、高三酰甘油血症、高低密度脂蛋白血症、低高密度脂蛋白血症、高血压、糖尿病、高尿酸血症、非酒精性脂肪性肝病(NAFLD)共计9项心血管代谢性危险因素后,控制一般情况变量,通过构建多因素Cox比例风险回归模型,估计各个心血管代谢性危险因素的回归系数β,以回归系数β为权重将所有心血管代谢性危险因素的评分相加得出心血管代谢危险因素危险总评分],将心血管代谢危险因素危险总评分按照四分位数分为三组:P75组;分别于2017年,2019年和2021年通过面访和死因监测系统搜索的方式完成随访。采...  相似文献   
99.
The prognostic value of hypocholesterolemia in hospitalized patients   总被引:3,自引:0,他引:3  
Clinical observations show that severe illness often leads to hypocholesterolemia. To verify this finding and to define the relationship between serum cholesterol and a patient's prognosis, a study was conducted in two large hospital populations. Of 24,000 and 61,463 adult patients (populations I and II) an average of 3.8% and 3.6% died in hospital, respectively. The mean serum cholesterol levels of patients who died was significantly lower than that of those who survived (163.6 mg/dl versus 217.8 mg/dl;P < 0.0001). The average cholesterol of surviving patients was similar to that of 6,543 healthy controls. During hospitalization serum cholesterol levels of 100 mg/dl were encountered in 1.2% and 3.6% of patients of populations I and II, respectively. The mortality of these hypocholesterolemic patients was about tenfold higher than average and showed a strong, inverse, linear relationship with serum cholesterol concentrations. Patients whose serum cholesterol level dropped to less than 45 mg/dl did not survive. These data show that in severely ill patients serum cholesterol may decline to very low concentrations, and the prognosis is reflected by the degree of hypocholesterolemia, which thus may serve as a clinically useful prognostic parameter. Correspondence to: E. Windler  相似文献   
100.
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