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   367篇
  免费   17篇
耳鼻咽喉   4篇
儿科学   14篇
妇产科学   4篇
基础医学   24篇
临床医学   30篇
内科学   87篇
皮肤病学   2篇
神经病学   27篇
外科学   34篇
综合类   6篇
预防医学   83篇
眼科学   2篇
药学   45篇
中国医学   14篇
肿瘤学   8篇
  2023年   2篇
  2022年   16篇
  2021年   27篇
  2020年   14篇
  2019年   6篇
  2018年   14篇
  2017年   11篇
  2016年   7篇
  2015年   10篇
  2014年   12篇
  2013年   17篇
  2012年   21篇
  2011年   15篇
  2010年   10篇
  2009年   6篇
  2008年   13篇
  2007年   18篇
  2006年   24篇
  2005年   13篇
  2004年   22篇
  2003年   26篇
  2002年   15篇
  2001年   9篇
  2000年   8篇
  1999年   7篇
  1998年   4篇
  1997年   1篇
  1994年   2篇
  1993年   2篇
  1992年   2篇
  1991年   3篇
  1990年   3篇
  1989年   1篇
  1988年   2篇
  1987年   6篇
  1986年   3篇
  1985年   3篇
  1984年   1篇
  1982年   3篇
  1981年   1篇
  1979年   2篇
  1978年   1篇
  1976年   1篇
排序方式: 共有384条查询结果,搜索用时 15 毫秒
41.
Marine n-3 polyunsaturated fatty acids alter cardiac phospholipids and prevent cardiac pathology in rodents subjected to pressure overload. This approach has not been evaluated in humans or large animals with hypertension-induced pathological hypertrophy. We evaluated docosahexaenoic acid (DHA) in old female dogs with hypertension caused by 16 weeks of aldosterone infusion. Aldosterone-induced hypertension resulted in concentric left ventricular (LV) hypertrophy and impaired diastolic function in placebo-treated dogs. DHA supplementation increased DHA and depleted arachidonic acid in cardiac phospholipids, but did not improve LV parameters compared to placebo. Surprisingly, DHA significantly increased serum aldosterone concentration and blood pressure compared to placebo. Cardiac mitochondrial yield was decreased in placebo-treated hypertensive dogs compared to normal animals, which was prevented by DHA. Extensive analysis of mitochondrial function found no differences between DHA and placebo groups. In conclusion, DHA did not favorably impact mitochondrial or LV function in aldosterone hypertensive dogs.  相似文献   
42.
The leaves and the root extracts of Moringa stenopetala were tested in vitro against trypomastigotes of Trypanosoma brucei, Trypanosoma cruzi and L. donovani amastigotes. The fresh root wood ethanol extract and the dried leaves acetone extract were found to be active against T. brucei with an ED(50) value of 9.2 microg/mL and 10.0 microg/mL respectively. All the other extracts were inactive against all the tested parasite forms.  相似文献   
43.
44.
45.
Girma S  Paton D 《Health economics》2006,15(9):1021-1032
In this paper, we demonstrate how matching estimators can be used to evaluate policy interventions which are implemented in relatively few regions at different times. Our technique is based on translating calendar time into 'experimental time' to provide a common starting point for entry by different areas into the scheme. Such an approach is likely to have many applications, in particular to cases of state- or country-level interventions for which only aggregate data are available. We illustrate the technique using the case of free over-the-counter access to emergency birth control for teenagers at pharmacies in England. We construct matching estimates of the impact of this scheme on the under-18 conception rate in local authorities. Irrespective of either the matching or the adjustment procedure, we find no evidence that over-the-counter emergency birth control schemes lead to lower teenage pregnancy rates.  相似文献   
46.
Yellow fever (YF) is a mosquito-borne vaccine-preventable disease with high mortality. In West Africa, low population immunity increases the risk of epidemic transmission. A cluster survey was conducted to determine the effectiveness of a mass immunization campaign using 17D YF vaccine in internally displaced person (IDP) camps following a reported outbreak of YF in Liberia in February 2004. Administrative data of vaccination coverage were reviewed. A cluster sample size was determined among 17,384 shelters using an 80% vaccination coverage threshold. A questionnaire eliciting demographic information, household size, and vaccination status was distributed to randomly selected IDPs. Data were analyzed to compare vaccination coverage rates of administrative versus survey data. Among 87,000 persons estimated living in IDP camps, administrative data recorded 49,395 (57%) YF vaccinated persons. A total of 237 IDPs were surveyed. Of survey respondents, 215 (91.9%, 95% CI 88.4-95.4) reported being vaccinated during the campaign and 196 (83.5%, 95% CI 78.6-88.5) possessed a valid campaign vaccination card. The median number of IDPs living in a shelter was 4 (range, 1-8) and 69,536 persons overall were estimated to be living in IDP camps. Coverage rates from a rapid survey exceeded 90% by self-report and 80% by evidence of a vaccination card, indicating that the YF immunization campaign was effective. Survey results suggested that administrative data overestimated the camp population by at least 20%. An emergency, mop-up vaccination campaign was avoided. Coverage surveys can be vital in the evaluation of emergency vaccination campaigns by influencing both imminent and future immunization strategies.  相似文献   
47.
The purpose of this report is to explore angioplasty and stenting with cerebral embolic protection as a salvage procedure for a compromised carotid-subclavian bypass in the presence of antegrade vertebral artery flow. A 76-year-old woman with a carotid-subclavian bypass presented with graft infection. Failure of medical therapy to treat the infection prompted surgical removal of the graft. The native subclavian artery was still patent, but a severe complex proximal stenosis was present with antegrade flow into the left vertebral artery. Angioplasty and stenting of the subclavian artery was performed with cerebral protection achieved by positioning a FilterWire EX in the left vertebral artery via the left brachial artery approach. Deployment of a filter device in the vertebral artery via the brachial or radial approach can provide embolic protection without interfering with the subclavian artery stenting. The successful treatment of the subclavian artery enabled the complete removal of the infected graft without need for major vascular reconstruction.  相似文献   
48.
Postendarterectomy carotid artery pseudo-aneurysm (CPA) is a relatively infrequent complication with an estimated incidence of 0.3%-0.6%. A report from a single center experience on open-surgical repair of CPA has shown the associated high morbidity and mortality. Endovascular therapy is emerging as a safer alternative to open-surgical therapy. We describe two cases of CPA treated with commercially available Viabahn stent graft system (Gore AL, Flagstaff, AZ).  相似文献   
49.
ObjectiveAdverse birth outcomes, which include stillbirth, preterm birth, low birthweight, congenital abnormalities, and stillbirth, are the leading cause of neonatal and infant mortality worldwide. We assessed adverse birth outcomes and associated factors among mothers who gave birth in Bale zone hospitals, Oromia, Southeast Ethiopia.MethodsWe used systematic random sampling in this cross-sectional study. We identified factors associated with adverse birth outcomes using bivariate analysis and multivariable logistic regression analysis.ResultsThe proportion of adverse birth outcomes among participants was 21%. Of 576 births, 70 (12.2%) were low birthweight, 49 (8.5%) were preterm birth, 45 (7.8%) were stillbirth, and 18 (3.1%) infants had congenital anomalies. Inadequate antenatal care (adjusted odds ratio [AOR] = 6.58, 95% confidence interval [CI] 3.25–13.32), multiple pregnancy (AOR  =  4.74, 95% CI 1.55–14.45), premature rupture of membranes in the current pregnancy (AOR = 2.31, 95% CI 1.26–4.21), hemoglobin level  < 11 g/dL (AOR = 3.22, 95% CI 1.85–5.58), and mid-upper arm circumference less than 23 cm (AOR = 5.93, 95% CI 3.49–10.08) were all significantly associated with adverse birth outcomes.ConclusionsApproximately one in five study participants had adverse birth outcomes. Increasing antenatal care uptake, ferrous supplementation during pregnancy, and improving the quality of maternal health services are recommended.  相似文献   
50.
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