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   5036篇
  免费   374篇
  国内免费   32篇
耳鼻咽喉   25篇
儿科学   166篇
妇产科学   86篇
基础医学   625篇
口腔科学   155篇
临床医学   466篇
内科学   1105篇
皮肤病学   93篇
神经病学   277篇
特种医学   167篇
外科学   788篇
综合类   283篇
一般理论   5篇
预防医学   418篇
眼科学   170篇
药学   302篇
中国医学   11篇
肿瘤学   300篇
  2023年   44篇
  2022年   96篇
  2021年   176篇
  2020年   116篇
  2019年   136篇
  2018年   138篇
  2017年   116篇
  2016年   126篇
  2015年   119篇
  2014年   157篇
  2013年   196篇
  2012年   317篇
  2011年   287篇
  2010年   178篇
  2009年   165篇
  2008年   216篇
  2007年   239篇
  2006年   237篇
  2005年   220篇
  2004年   188篇
  2003年   189篇
  2002年   168篇
  2001年   141篇
  2000年   157篇
  1999年   130篇
  1998年   84篇
  1997年   55篇
  1996年   45篇
  1995年   62篇
  1994年   37篇
  1993年   36篇
  1992年   60篇
  1991年   65篇
  1990年   73篇
  1989年   75篇
  1988年   50篇
  1987年   62篇
  1986年   52篇
  1985年   46篇
  1984年   34篇
  1983年   27篇
  1982年   36篇
  1981年   31篇
  1980年   32篇
  1979年   33篇
  1978年   23篇
  1977年   25篇
  1976年   23篇
  1975年   21篇
  1973年   20篇
排序方式: 共有5442条查询结果,搜索用时 0 毫秒
31.
OBJECTIVES: To investigate differences in presentation and management of Indigenous and non-Indigenous patients hospitalised with acute myocardial infarction (AMI). DESIGN: Retrospective review of hospital medical records. PARTICIPANTS AND SETTING: 122 patients with definite or possible AMI admitted to hospitals in the Top End of the Northern Territory (NT) in 1996. MAIN OUTCOME MEASURES: Percentage receiving thrombolytic therapy; delays from symptom onset to primary and emergency department presentations, first and diagnostic electrocardiograms, thrombolytic therapy and aspirin; drugs prescribed during hospitalisation. RESULTS: Thrombolytic therapy was given to 12/41 Indigenous patients (29%) and 38/81 non-Indigenous patients (47%) (P = 0.06). Presentation delay over 12 hours was the reason for not giving thrombolytic therapy for 14/29 Indigenous patients (48%) and 8/43 non-Indigenous patients (19%) (P < 0.01). Median delay times were longer for Indigenous patients for all six categories of delay, although the difference was significant only for delay to emergency department presentation (10:00 versus 3:26 hours; P < 0.01) and to diagnostic electrocardiogram (8:10 versus 3:50 hours; P < 0.01). Delays were also longer for patients from rural compared with urban areas. Once diagnosed, Indigenous patients were as likely as non-Indigenous patients to receive aspirin (93% versus 96%) and beta-blockers (70% versus 69%) and more likely to receive angiotensin-converting enzyme inhibitors (60% versus 40%; P = 0.03). CONCLUSIONS: Delays in presentation affect Indigenous people living in rural and urban areas as well as non-Indigenous people living in rural areas. Concerted efforts are needed to improve health service access in rural areas and to encourage Indigenous people with persistent chest pain to present earlier.  相似文献   
32.
Ong EL  Lim NL  Koay CK 《Anaesthesia》2000,55(3):260-262
A randomised, prospective trial was conducted to assess the efficacy of various means of alleviating the pain of subcutaneous lidocaine infiltration. One hundred and twenty-two patients were randomly allocated to different groups to receive buffered lidocaine 1%, warmed lidocaine 1% or infiltration by the counter-irritation technique. A visual analogue pain score was recorded at different stages of cannulation and results showed that pain scores were significantly lower in the group receiving buffered lidocaine 1% (p < 0.02) and in the counter-irritation group (p < 0.05). Thus buffering lidocaine 1% and administration of lidocaine 1% by the counter-irritation technique is effective in relieving the pain of lidocaine infiltration.  相似文献   
33.
34.
Infertility is a growing public health problem. Consumption of antioxidant bioactive food compounds (BFCs) that include micronutrients and non-nutrients has been highlighted as a potential strategy to protect against oxidative and inflammatory damage in the male reproductive system induced by obesity, alcohol, and toxicants and, thus, improve spermatogenesis and the fertility parameters. Paternal consumption of such dietary compounds could not only benefit the fathers but their offspring as well. Studies in the new field of paternal origins of health and disease show that paternal malnutrition can alter sperm epigenome, and this can alter fetal development and program an increased risk of metabolic diseases and breast cancer in adulthood. BFCs, such as ascorbic acid, α-tocopherol, polyunsaturated fatty acids, trace elements, carnitines, N-acetylcysteine, and coenzyme Q10, have been shown to improve male gametogenesis, modulate epigenetics of germ cells, and the epigenetic signature of the offspring, restoring offspring metabolic health induced by stressors during early life. This indicates that, from a father’s perspective, preconception is a valuable window of opportunity to start potential nutritional interventions with these BFCs to maximize sperm epigenetic integrity and promote adequate fetal growth and development, thus preventing chronic disease in adulthood.  相似文献   
35.
36.
INTRODUCTIONPercutaneous transluminal angioplasty (PTA) is commonly used to treat patients with chronic limb-threatening ischaemia (CLTI). This study aimed to examine the mortality and functional outcomes of patients with CLTI who predominantly had diabetes mellitus in a multi-ethnic Asian population in Singapore.METHODSPatients with CLTI who underwent PTA between January 2015 and March 2017 at the Vascular Unit at Singapore General Hospital, Singapore, were studied. Primary outcome measures were 30-day unplanned readmission, two-year major lower extremity amputation (LEA), mortality rates, and ambulation status at one, six and 12 months.RESULTSA total of 221 procedures were performed on 207 patients, of whom 184 (88.9%) were diabetics. The one-, six- and 12-month mortality rate was 7.7%, 16.4% and 21.7%, respectively. The two-year LEA rate was 30.0%. At six and 12 months, only 96 (46.4%) and 93 (44.9%) patients were ambulant, respectively. Multivariate analysis revealed that preoperative ambulatory status, haemoglobin, Wound Ischaemia and foot Infection (WIfI) score, and end-stage renal failure (ESRF) were independent predictors of one-year ambulatory status. Predictors of mortality at one, six and 12 months were ESRF, preoperative albumin level, impaired functional status and employment status.CONCLUSIONPTA for CLTI was associated with low one-year mortality and two-year LEA rates but did not significantly improve ambulation status. ESRF and hypoalbuminaemia were independent predictors of mortality. ESRF/CKD and WIfI score were independent predictors of loss of ambulation at six months and one year. We need better risk stratification for patients with CLTI to decide between initial revascularisation and an immediate LEA policy.  相似文献   
37.
本文用 BALB/3T3 A31-1-13细胞系研究了煤尘抽提物的转化活性。亚硝化和未亚硝化的煤尘抽提物都能诱发细胞发生转化且有剂量反应关系.但亚硝化煤尘抽提物的转化活性比未亚硝化者高。从转化集落分离出来的细胞具有赘生转化的一些特征,如细胞生长迅速、接触抑制消失和停泊不依赖性生长等.本文结果看来支持煤矿工胃癌高发原因的煤尘假说。  相似文献   
38.
39.
40.
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