全文获取类型
收费全文 | 51030篇 |
免费 | 3900篇 |
国内免费 | 904篇 |
专业分类
耳鼻咽喉 | 223篇 |
儿科学 | 471篇 |
妇产科学 | 668篇 |
基础医学 | 2435篇 |
口腔科学 | 514篇 |
临床医学 | 5818篇 |
内科学 | 4405篇 |
皮肤病学 | 561篇 |
神经病学 | 749篇 |
特种医学 | 1119篇 |
外国民族医学 | 1篇 |
外科学 | 3608篇 |
综合类 | 12127篇 |
现状与发展 | 2篇 |
一般理论 | 39篇 |
预防医学 | 17071篇 |
眼科学 | 386篇 |
药学 | 2575篇 |
285篇 | |
中国医学 | 2139篇 |
肿瘤学 | 638篇 |
出版年
2024年 | 153篇 |
2023年 | 823篇 |
2022年 | 1553篇 |
2021年 | 2127篇 |
2020年 | 2469篇 |
2019年 | 1713篇 |
2018年 | 1658篇 |
2017年 | 1515篇 |
2016年 | 1577篇 |
2015年 | 1534篇 |
2014年 | 3836篇 |
2013年 | 3976篇 |
2012年 | 3392篇 |
2011年 | 3790篇 |
2010年 | 3160篇 |
2009年 | 2704篇 |
2008年 | 2982篇 |
2007年 | 2733篇 |
2006年 | 2395篇 |
2005年 | 1968篇 |
2004年 | 1621篇 |
2003年 | 1271篇 |
2002年 | 964篇 |
2001年 | 795篇 |
2000年 | 696篇 |
1999年 | 521篇 |
1998年 | 452篇 |
1997年 | 415篇 |
1996年 | 368篇 |
1995年 | 345篇 |
1994年 | 253篇 |
1993年 | 160篇 |
1992年 | 157篇 |
1991年 | 189篇 |
1990年 | 164篇 |
1989年 | 159篇 |
1988年 | 143篇 |
1987年 | 116篇 |
1986年 | 123篇 |
1985年 | 116篇 |
1984年 | 103篇 |
1983年 | 93篇 |
1982年 | 99篇 |
1981年 | 70篇 |
1980年 | 79篇 |
1979年 | 43篇 |
1978年 | 67篇 |
1977年 | 63篇 |
1976年 | 63篇 |
1975年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 78 毫秒
81.
Efficacy of an air-cleaning device equipped with a high efficiency particulate air filter in house dust mite respiratory allergy 总被引:3,自引:2,他引:1
The efficacy of an air-cleaning device equipped with a high efficiency particulate air (HEPA) filter (without further avoidance measures) was studied in patients allergic to house dust mite. The effects of the air-cleaner on indoor Dermatophagoides sp. levels, symptom score and bronchial hyperresponsiveness in nine mite-allergic patients were assessed using a cross-over controlled study. No significant effect was demonstrated on indoor Dermatophagoides sp. levels when comparing the period of air-cleaner activity (2 months) with the control period (2 months). The Dermatophagoides sp. levels in the houses studied were lower than the risk level for asthmatic attacks, making it difficult to assess any effect on asthma; however, neither bronchial hyperresponsiveness nor rhinitis symptom score were changed by air-cleaner activity. During the trial period, however the mean level of Dermatophagoides sp. allergen in the houses changed spontaneously from 4.4 micrograms/g (mean level in the first 2 trial months) to 1.75 micrograms/g of dust (second 2 months) (P less than 0.05). Owing to this change, the mean rhinitis symptom score also decreased (P less than 0.05), even if no significant correlation was demonstrated (r = 0.4 P = 0.089). HEPA filter air-cleaners appear insufficient as substitutes for standard avoidance measures in mite allergic patients. 相似文献
82.
化工行业职业性机械伤害危险因素的病例-交叉方法研究 总被引:6,自引:0,他引:6
目的 研究化工行业机械伤害的有关诱发因素,估计其作用强度。方法 采用病例-交叉设计的方法。以操作和检修时受伤的化工工人为研究对象,每个对象在受伤后2d内完成调查,收集他们受伤前10min、上一工作日同一段时间和受伤前1周内有关诱发因素暴露的信息,用配对时间段方法和一般频数法进行分析,评估各种诱发因素的危险度。结果 一般频数法分析的结构表明,操作方法异常、设备工具缺陷、工作紧迫、注意力不集中、不使用防护用品、精神状况较差、与同事配合不协调、工作环境发生变化等瞬时危害因素的RR值及95%可信限的下限均大于1。配对时间段方法分析的结果与其相拟,但95%可信限较宽。结论 化工行业职业性机械伤害的发生存在着诸多诱发因素。病例-交叉研究中的一般频数法与配对时间段方法相比,前者所得结果较为可靠,研究的相对效率较高。建议进一步使用多个时间段方法进行研究,以减小混杂因素的影响。 相似文献
83.
Teaching of medical ethics 总被引:1,自引:0,他引:1
Teaching medical ethics in Manchester within the introductory course of obstetrics and gynaecology is a joint activity with the Centre for Social Ethics and Policy. This interdisciplinary teaching has evolved through lecture sessions with small-group discussions dealing with topics of interest in human reproduction. The small-group discussion have been replaced by an open debate conducted by the students. Their own involvement and participation and an exposure to the disciplines of the humanities has broadened their approach to different ways of problem-solving of these real issues. 相似文献
84.
本文介绍了不同的影像色彩模式和影像文件常见存储格式的特点及其在应用上的优缺点,分析了影像色彩模式、文件存储的格式与影像质量、用途的关系。 相似文献
85.
文章针对目前医学生“网络成瘾症”的现状进行了分析,并指出了产生的原因和解决问题的办法,以求达到标本兼治。最后提出三点预防医学生“网络成瘾症”的对策:一是高校及其附属医院要为医学生营造宽松愉快的学习、生活环境;二是呼吁家长关注医学生身心发展的特殊规律,建立良好的家庭环境;三是建立和完善与网络社会相应的法律法规,规范医学生的网上行为。 相似文献
86.
Geste antagonistes, or sensory tricks, are well described in focal dystonia affecting the neck, hand, and face. Improvement in dystonic movements is typically maintained while the trick is performed, but disappears when the geste ends. We investigated the phenomenological features of geste antagoniste maneuvers in 19 patients with idiopathic lower cranial dystonia who were prospectively evaluated over a period of 6 years. Of the 19, 10 were men, mean age of onset was 49.8 years, and the most commonly involved lower cranial area was the jaw (10 patients). In most patients, dystonia was task-specific. Taking advantage of the improvement with a sensory geste, we manufactured oral appliances that mimicked the geste in 8 patients, and 3 continue to use it. 相似文献
87.
88.
89.
对综合大学医学生心理健康干预的研究 总被引:1,自引:0,他引:1
[目的 ]探讨具有改善医学生心理健康水平的较长期效果 ,并可在自然条件下提高医学生心理素质的有效途径 .[方法 ]采用 16种人格因素量表多角度地分析当代医学生的心理素质状况 ,在此基础上 ,连续 2年先后在全年级开展多种形式的心理健康干预活动 .[结果 ]医学生的人格可塑性很强 ,通过多种途径的心理健康教育及心理辅导 ,完全能改善医学生的某些人格因素 ,提高其心理健康水平 .[结论 ]心理健康干预活动对于提高医学生心理健康水平是有效的 相似文献
90.
Objectives: To validate the accuracy of using probabilistic linkage for matching de‐identified ambulance records to a state trauma registry. Methods: This was a retrospective cohort analysis. Three thousand nine hundred nineteen true matches between ambulance and state trauma registry data from 1998 to 2003 were identified by deterministic matching on trauma identification number and verified by human review. Two thousand thirty‐eight ambulance records from trauma patients not meeting criteria for a true match, and an identical number of trauma registry records randomly selected from the one local county served by a different EMS provider, were included as nonmatches. There were 17 variables considered for linkage, which included the following: age, gender, race, county, hospital, date, rural setting, call and arrival times, mechanism, penetrating injury, vital signs, intubation, and intoxication. Probabilistic linkage was used to link the two data sets, using seven different combinations of common variables (maximum, 17; minimum, 4). The sensitivity and specificity of identifying true matches and nonmatches (95% confidence intervals [95% CI]) were calculated for each combination of variables. Results: Using all 17 available variables, 3,766 of 3,919 true matches were appropriately linked (sensitivity, 96.1%; 95% CI = 95.4% to 96.7%), with eight mismatches (specificity, 99.6%; 95% CI = 99.2% to 99.8%). Sensitivity fell below 95% with < 15 variables; however, sensitivity was very dependent on the inclusion of variables with high discriminatory power. Specificity remained >98% regardless of the number of variables included. Conclusions: Probabilistic linkage is a valid method for matching ambulance records to a trauma registry without the use of patient identifiers; however, the sensitivity of identifying true matches is critically dependent on the number and type of common variables included in the analysis. 相似文献