全文获取类型
收费全文 | 14911篇 |
免费 | 1158篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 173篇 |
儿科学 | 261篇 |
妇产科学 | 109篇 |
基础医学 | 1098篇 |
口腔科学 | 207篇 |
临床医学 | 1025篇 |
内科学 | 933篇 |
皮肤病学 | 394篇 |
神经病学 | 640篇 |
特种医学 | 507篇 |
外科学 | 619篇 |
综合类 | 849篇 |
现状与发展 | 1篇 |
预防医学 | 7020篇 |
眼科学 | 117篇 |
药学 | 1772篇 |
3篇 | |
中国医学 | 52篇 |
肿瘤学 | 408篇 |
出版年
2024年 | 16篇 |
2023年 | 183篇 |
2022年 | 272篇 |
2021年 | 500篇 |
2020年 | 552篇 |
2019年 | 535篇 |
2018年 | 499篇 |
2017年 | 532篇 |
2016年 | 522篇 |
2015年 | 504篇 |
2014年 | 1023篇 |
2013年 | 1412篇 |
2012年 | 980篇 |
2011年 | 1043篇 |
2010年 | 776篇 |
2009年 | 762篇 |
2008年 | 750篇 |
2007年 | 651篇 |
2006年 | 593篇 |
2005年 | 462篇 |
2004年 | 407篇 |
2003年 | 320篇 |
2002年 | 251篇 |
2001年 | 227篇 |
2000年 | 237篇 |
1999年 | 148篇 |
1998年 | 179篇 |
1997年 | 150篇 |
1996年 | 188篇 |
1995年 | 160篇 |
1994年 | 131篇 |
1993年 | 108篇 |
1992年 | 152篇 |
1991年 | 116篇 |
1990年 | 107篇 |
1989年 | 87篇 |
1988年 | 84篇 |
1987年 | 75篇 |
1986年 | 55篇 |
1985年 | 77篇 |
1984年 | 78篇 |
1983年 | 51篇 |
1982年 | 60篇 |
1981年 | 38篇 |
1980年 | 36篇 |
1979年 | 21篇 |
1978年 | 20篇 |
1977年 | 19篇 |
1976年 | 16篇 |
1974年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 109 毫秒
91.
This paper considers the immediate post‐traumatic reactions of rescue personnel who were exposed to the Hilton Hotel bombing in Sinai. The entire rescue personnel (n = 26) were assessed and separated into two groups on the basis of previous exposure to the same type of trauma. The results suggest that among rescue personnel, those with previous exposure had a lower level of post‐traumatic symptoms than those who were being exposed for the first time. This supports the hypothesis that previous exposure to the same type of trauma has an immunizing effect for subsequent same type of traumatic event among rescue personnel. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
92.
Objectives: Previous studies have been inconsistent with regard to the extent to which stress perception, rather than stressor exposure, predicts negative health symptoms. Because sex differences have been observed in all three of these variables, in this study the possibility that sex differences also exist in the relationships between them is investigated. Methods: Self‐report inventories of perceived stress, stressor exposure, and negative health symptoms were given to 107 young‐adult participants (65 females, 42 males). Results: Sex differences were observed in the associations among perceived stress, stressor exposure, and negative health symptom rates. Specifically, while higher perceived stress and higher stressor exposure rates independently predicted higher negative health symptoms rates in females, only higher stressor exposure rates independently predicted higher negative health symptoms in males. Indeed, unexpectedly, after controlling for exposure to stressors there was a trend towards higher perceived stress predicting lower negative health symptoms in males. Conclusions: While exposure to stress was a significant negative predictor of health for both sexes, perception of stress was predictive only for females. One implication of this finding is that different psychological models are needed to predict health symptoms in the two sexes. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
93.
目的制定防护措施,减少危险药物的暴露风险。方法通过文献,查找危险药物暴露对职业接触的医务人员健康危害的依据,呼吁政府部门和医院领导,加强对危险药物暴露的管理,科学设置配药场所,建立教育和培训制度,采取有效防护措施,确保职业性接触危险药物的医务人员身体健康。结果国内许多医院建立了静脉药物配置中心,由受过培训的专业人员,严格按照操作程序进行抗肿瘤等危险药物的配置,减少了危险药物暴露的机会。结论我国的医务人员化疗防护培训严重不足,防范意识薄弱,应引起有关部门和医院领导的高度重视,制定并落实有效的防护措施,确保医务人员的职业安全。 相似文献
94.
医疗照射剂量水平及其防护 总被引:1,自引:0,他引:1
本文讨论了医疗照射的频度、剂量水平和防护问题。诊断X线检查频度在发达国家为每年每千人300—900人次,在发展中国家为100—200人次/千人·年,我国为124.5人次/千人·年;平均有效剂量当量在发达国家为1mSv/年·人,全世界平均值为0.4mSv/年·人,我国为 0.5mSv/年·人;医疗照射所致超额死亡率在发达国家估计为10—15/百万人,我国为4.27/百万人。 我国的诊断X线检查频度和剂量水平将进一步增长,为减少医疗照射,我们必须采取预防措施。 相似文献
95.
J. Angerer G. Lehnert 《International archives of occupational and environmental health》1990,61(8):7-10
Summary Stainless steel welders (n = 103) were examined. To estimate external exposure, personal air sampling was used. Internal exposure was quantified by
the determination of nickel levels in erythrocytes, plasma and urine. Men and women (n = 123) were examined for control purposes. In the plasma and erythrocytes of the controls the nickel concentration was below
the level of detection (< 1.81 μg/l). The element concentrations in urine were between < 0.1 and 13.3 μg/l. Of the controls
95% showed nickel levels in urine below 2.2 μg/l (reference value). The average concentration of nickel in the air was 93
± 81 μg/m3. The average concentration of nickel in the plasma samples was 4.9 ± 4.0 μg/l (95th percentile 12.8 μg/L). In erythrocytes
nickel could not be detected. The nickel concentrations in the urine of the welders were 18.5 ± 28.5 μg/l on average (95th
percentile 52.5 μg/l). Only a weak correlation between the nickel levels of plasma and urine could be detected (Curine = 2.07 + 8.45 Cplasma; r = 0.294; p < 0.01). Based on our results and on the reported literature a future limit value for the nickel concentration in urine should
lay between 30 and 50 μg/l. This value corresponds to an external exposure of 500 μg nickel per cubic metre. 相似文献
96.
Cardiovascular malformations and organic solvent exposure during pregnancy in Finland 总被引:2,自引:0,他引:2
In order to investigate the possible association between cardiovascular malformations and maternal exposure to organic solvents during the first trimester of pregnancy, 569 cases and 1,052 controls were retrospectively studied. The cases represented all infants with diagnosed cardiovascular malformations born in Finland in 1982-1984, and the controls were randomly selected from all normal births in the country during the same period. All mothers were interviewed approximately 3 months after delivery by a midwife using a structured questionnaire. Exposures to organic solvents at work during the first trimester of pregnancy were slightly more prevalent among the mothers of affected infants (10.4%) than among those of controls (7.8%). Logistic regression analysis of exposure to organic solvents showed an adjusted relative odds ratio of 1.3 (95% confidence interval, 0.8-2.2). In the analysis of ventricular septal defect, exposure to organic solvents showed an adjusted relative odds ratio of 1.5 (95% confidence interval, 1.0-3.7). 相似文献
97.
噪声对耳蜗外淋巴中某些离子含量的影响 总被引:3,自引:0,他引:3
将18只豚鼠分为1个对照组和2个暴露组,分别暴露于115dB(SPL)、125dB(SPL),1.5kHz纯音0.5h,以皮层听区诱发电位为检查指标,观察暴露前后动物听力的改变,并测定了耳蜗外淋巴中Na+、K+、Ca2+、Mg2+离子含量的变化。结果表明,声暴露后各组动物听阈明显提高,且125dB组听力损失明显高于115dB组。125dB声暴露后,耳蜗外淋巴中Ca2+明显降低,而115dB组与正常对照组相比差异无显著性。声暴露对其它离子的含量没有影响。结果提示Ca2+可能与声损伤,特别是与永久性听力损失有关。 相似文献
98.
P Oksa H Koskinen J P Rinne A Zitting P Roto M S Huuskonen 《American journal of industrial medicine》1992,21(4):561-567
Exposure to mineral dust was studied among construction workers (N = 437) with the aid of a questionnaire and a chest X-ray examination of the lungs. The results of the questionnaire showed that 81% of the construction workers had been exposed to asbestos. Exposure had occurred in all of the occupational groups studied. Pleural plaques and/or lung fibrosis (ILO greater than or equal to 1/1) were found in 26% of the examined workers; the prevalence varied from 18 to 40% among the various occupational groups. Comparison with a representative sample of the Finnish male population from another investigation indicates that the frequency of lung fibrosis (ILO greater than or equal to 1/1) is at least two times higher among the examined construction workers than among the general population. It seems likely that exposure to asbestos dust can be considered an etiological factor for an appreciable number of the X-ray findings. 相似文献
99.
100.
Iman Al‐Saleh Andrew Taylor Richard Hinton 《International journal of environmental health research》1992,2(4):184-191
Erythrocyte protoporphyrin and blood lead concentrations were measured in samples from 583 Saudi children attending the outpatient clinics. Erythrocyte protoporphyrin concentrations showed poor correlation with blood lead concentrations of 25 ug dl?1 and below. Measurement of erythrocyte protoporphyrin as a primary test for lead exposure is not recommended. 相似文献