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   771篇
  免费   32篇
  国内免费   6篇
耳鼻咽喉   3篇
儿科学   40篇
妇产科学   8篇
基础医学   43篇
口腔科学   29篇
临床医学   97篇
内科学   53篇
皮肤病学   2篇
神经病学   64篇
特种医学   44篇
外科学   91篇
综合类   64篇
预防医学   211篇
眼科学   11篇
药学   36篇
中国医学   8篇
肿瘤学   5篇
  2023年   7篇
  2022年   14篇
  2021年   23篇
  2020年   17篇
  2019年   22篇
  2018年   17篇
  2017年   13篇
  2016年   14篇
  2015年   19篇
  2014年   37篇
  2013年   75篇
  2012年   19篇
  2011年   38篇
  2010年   27篇
  2009年   22篇
  2008年   23篇
  2007年   42篇
  2006年   25篇
  2005年   24篇
  2004年   33篇
  2003年   33篇
  2002年   18篇
  2001年   14篇
  2000年   18篇
  1999年   13篇
  1998年   24篇
  1997年   24篇
  1996年   19篇
  1995年   15篇
  1994年   18篇
  1993年   9篇
  1992年   11篇
  1991年   9篇
  1990年   7篇
  1989年   7篇
  1988年   11篇
  1987年   5篇
  1986年   3篇
  1985年   4篇
  1984年   7篇
  1983年   2篇
  1982年   8篇
  1981年   8篇
  1980年   3篇
  1979年   4篇
  1978年   2篇
  1977年   1篇
  1975年   1篇
排序方式: 共有809条查询结果,搜索用时 15 毫秒
91.
This paper analyses the aggregate relationships between traffic accidents and real economic activity in Spain during the last 30 years. Our general approach is based on two basic assumptions: (1) the number of accidents depends on the use of cars and other exogenous variables, and (2) the level of economic activity affects variation in the stock of cars, as well as degree of utilization. We propose a novel turning point characterization for monthly seasonal data that allows to check whether economic and road accident cycles coincide and, to date the beginning and end of their respective cycles. Empirical results from this section are important in establishing posterior causal models and whether or not economic activity and road accidents have a common component in the long run and a varying lead-lag relationship, depending on the cycles. These models will be the basis to check when Spain will achieve the European Union figures in terms of the fatalities/accidents ratio under different scenarios. Empirical results as well as historical experiences from other European countries proved that reducing fatalities is not only a question of diminishing accidents rates.  相似文献   
92.
OBJECTIVES: To investigate whether the pattern of hospitalised injuries in injured child motor vehicle passengers involved in traffic crashes differs in rural and urban residents of New South Wales (NSW). METHODS: This study compared injuries of hospitalised child motor vehicle passengers resident in rural areas with those from urban areas. The NSW Inpatient Statistics Collection (ISC), a population-based dataset, was used to select cases for the period of July 2000 to June 2004. The hospitalised injury rate was calculated according to urban/rural status using Poisson regression. Injury rate ratios (IRR) comparing rural and urban children were computed overall and for specific injury types. RESULTS: Overall, 1,286 children (aged 0-15 years) residing in NSW were identified from the NSW ISC internally linked datasets as being separated from hospital for injuries resulting from a motor vehicle crash. The overall hospitalised injury incidence rates for child motor vehicle passengers resident in rural and urban NSW areas were 46.75 (95% CI 36.63-59.66) and 20.13 (95% CI 17.94-22.58) per 100,000 children respectively. The rural/urban IRR for comparing the incidence of hospitalisation was significantly elevated (IRR=2.10, 95% CI 1.78-2.48). The IRR was also significantly elevated across most injury types. The largest risk disparity between rural and urban children was in 9-12 year-olds (IRR=2.33, 95% CI 1.73-3.13). CONCLUSION AND IMPLICATIONS: There is an elevated injury incidence rate in rural resident children, compared with their urban counterparts. This differential should be addressed in future road safety initiatives.  相似文献   
93.
94.

Objective

The study aims to determine the high risk gestational week (GW) and/or birth weight (BW) of the preterm neonate, below which perinatal hypoxic cerebral injuries are expected to occur.

Material and methods

Eighty preterm neonates, born at or before 37 GW, were included. Twenty-three of them were <32 GW and 57 >32 GW. Also, 28 of them were <1500 g and 52 >1500 g. Imaging was done by transcranial ultrasound with 4–9 MHz curvilinear probe. CT scan was additionally performed for only 18 candidates. The study protocol was approved by the ethics committee in Al-Mana General Hospital (AGH).

Results

Intraventricular hemorrhage (IVH) was diagnosed in six preterm neonates <32 GW and two >32 GW. Three <32 GW and one >32 GW presented with hypoxic ischemic encephalopathy (HIE) with no hemorrhage. Two preterm neonates <32 GW had both IVH & HIE. All positive cases were below 1500 g BW.

Conclusion

Preterm neonates <32 GW and/or <1500 g are highly susceptible for HIE and/or IVH. Thus, special medical care, including post-labor hospitalization in well equipped special baby care units (SCBU) and routine transcranial ultrasound (TCUS) screening is recommended for those preterm neonates.  相似文献   
95.
96.

Aim

This study aimed to prospectively examine whether low normal glucose levels and hypoglycaemia are associated with increased mortality due to external causes, especially unintentional accidents.

Methods

A total of 345,318 normoglycaemic Korean adults who had undergone health examinations during 2002–2003 were followed-up to 2013. To avoid potential biases related to glucose-lowering medication use, those with known diabetes or hyperglycaemia were excluded.

Results

During 3.6 million person-years of follow-up, 1293 participants died because of unintentional accidents. Hazard ratios (HRs) for these accidental deaths were 1.26 (95% CI: 1.11–1.42), 1.60 (1.21–2.11) and 3.07 (1.37–6.85) for fasting serum glucose (FSG) levels of 70–79, 55–69 and < 55 mg/dL (3.9–4.4, 3.05–3.83 and < 3.05 mmol/L), respectively, compared with 80–99 mg/dL (4.44–5.5 mmol/L). FSG levels < 80 mg/dL were associated with an approximately 30% higher mortality due to accidents: specifically, 40% were non-fall-related injury; 50% were automobile-related; and 80% were motorcycle-related. The associations were weak (approximately 10% higher mortality, with P > 0.05 for each cause) for deaths due to traffic accidents (pedestrians, pedal cyclists), falls, intentional self-harm and physical assault. The population attributable risks for FSG levels < 80 mg/dL were 10% (95% CI: 2–18%) for non-fall-related injury, 11% (6–17%) for car accidents and 17% (6–27%) for motorcycle accidents.

Conclusion

FSG levels of 70–79 mg/dL (3.9–4.4 mmol/L) as well as < 70 mg/dL are risk factors for accidental death. Appropriate management of the impact of FSG levels < 80 mg/dL might reduce unintended deaths due to non-fall-related injury, and automobile and motorcycle accidents, by ≥ 10%.  相似文献   
97.
目的建立对四种鼠药的实验室应急检测方法,以应对突发公共卫生毒物中毒事件。方法采用气质联用法(GC/MS)测定毒鼠强、氟乙酰氨和高效液相色谱法(HPLC)测定敌鼠钠、溴敌隆,以鼠药标准和鼠药样品为对象,优化GC/MS和HPLC色谱、质谱条件,从而建立各鼠药的色谱图库和质谱图库。结果 GC/MS定性检测毒鼠强的特征离子和丰度比分别为212/240和2:1,氟乙酰胺的分别为44/77和1.5:1;敌鼠钠、溴敌隆以高效液相色谱双波长(285nm和260nm)检测,固体样品最低检测浓度为0.80 mg/kg,液体样品最低检测浓度为0.16 mg/L。结论研究方法对中毒事件中四种鼠药检测快速、结果可靠,适用于鼠药中毒实验室应急检测。  相似文献   
98.
99.
Purpose. To determine factors predictive of return to work (RTW) and days of total disability (TD) in a population of persons working at the time of lower extremity amputation.

Method. Retrospective chart and database review.

Results. Of 88 valid cases, 48% involved toe amputation, 23% transtibial, 14% partial foot, 14% transfemoral, and 2% high level. Fifty-eight percent of all subjects RTW, 19% were deemed ‘fit for work’, and 23% did not RTW. Days TD ranged from 0 to 1664, with a mean of 366 days. Toe amputation level showed a mean of 127 days of TD. Bivariate analysis showed amputation level, total costs to Workers Compensation Board (WCB), and days TD significantly related to RTW, and rehabilitation costs, vocational rehabilitation, work assessment, age, number of surgical procedures, number of days in acute care, and amputation level significantly related to days TD. In the multivariate model, only amputation level and higher gross annual income showed predictive value for RTW. However older age, more surgical procedures, less days in hospital, and higher amputation levels were all predictive of increased days TD.

Conclusion. Toe amputation level had a surprisingly high number of days TD, which may have significant potential economic and disability impact on the workplace. Other factors beyond simply amputation level (such as previous income level) are important considerations for RTW.  相似文献   
100.
Summary A study of non-intentional, motor vehicle-related, carbon monoxide-related deaths was performed on the case files of the Office of the Medical Examiner of Metropolitan Dade Country in Miami, FL (USA) during the years 1980–1984. A total of 15 cases were collected during that time period. These are presented in some detail. A discussion ensues that compares the similar circumstances of these cases, notably running the engine of an automobile in an enclosed space, with older reports in the literature which emphasized defective vehicle exhaust systems as the leading etiology for these deaths.  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