全文获取类型
收费全文 | 13638篇 |
免费 | 565篇 |
国内免费 | 141篇 |
专业分类
耳鼻咽喉 | 56篇 |
儿科学 | 131篇 |
妇产科学 | 84篇 |
基础医学 | 465篇 |
口腔科学 | 54篇 |
临床医学 | 1783篇 |
内科学 | 1147篇 |
皮肤病学 | 73篇 |
神经病学 | 393篇 |
特种医学 | 298篇 |
外科学 | 331篇 |
综合类 | 3113篇 |
预防医学 | 3175篇 |
眼科学 | 56篇 |
药学 | 2164篇 |
38篇 | |
中国医学 | 791篇 |
肿瘤学 | 192篇 |
出版年
2024年 | 17篇 |
2023年 | 102篇 |
2022年 | 308篇 |
2021年 | 355篇 |
2020年 | 429篇 |
2019年 | 258篇 |
2018年 | 260篇 |
2017年 | 303篇 |
2016年 | 508篇 |
2015年 | 553篇 |
2014年 | 1481篇 |
2013年 | 1364篇 |
2012年 | 1520篇 |
2011年 | 1679篇 |
2010年 | 1106篇 |
2009年 | 763篇 |
2008年 | 619篇 |
2007年 | 637篇 |
2006年 | 463篇 |
2005年 | 317篇 |
2004年 | 254篇 |
2003年 | 216篇 |
2002年 | 159篇 |
2001年 | 144篇 |
2000年 | 122篇 |
1999年 | 82篇 |
1998年 | 49篇 |
1997年 | 35篇 |
1996年 | 22篇 |
1995年 | 25篇 |
1994年 | 16篇 |
1993年 | 18篇 |
1992年 | 14篇 |
1991年 | 7篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 7篇 |
1987年 | 9篇 |
1986年 | 8篇 |
1985年 | 8篇 |
1984年 | 5篇 |
1982年 | 5篇 |
1981年 | 6篇 |
1980年 | 5篇 |
1978年 | 3篇 |
1975年 | 10篇 |
1974年 | 10篇 |
1973年 | 16篇 |
1972年 | 12篇 |
1970年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
目的 :评价平板式全数字心血管造影机在周围血管及非血管介入中的应用价值。方法 :对平板探测器(FPDD)X线成像与影像增强器 电视 (IITV)X线成像在动态范围、成像均匀性、对比度线性、对比分辨率等图像质量指标的检测及比较。随机选择上述两机型在周围血管及非血管介入诊疗病例图像资料各 6 0例 ,由三名高年资医师对其图像质量进行综合评价 ,记录评价结果 ,并进行比较。结果 :FPDD成像在动态范围、成像均匀性、对比度线性、对比分辨率等图像质量指标均优于IITV成像 ;在人体各部位周围血管及非血管介入诊疗中的图像综合评价结果也优于IITV成像。结论 :平板式全数字化心血管造影机不仅适用于心血管介入 ,同时能满足全身各部位周围血管及非血管介入诊疗的需要。 相似文献
32.
E. Hallier H. W. Goergens K. Hallier H. M. Bolt 《International archives of occupational and environmental health》1994,66(3):167-172
An intervention study was performed on 28 workers exposed by inhalation to styrene in the reinforced plastics industry and 20 controls not occupationally exposed to the compound. The workers involved were 14 laminators exposed to a time-weighted average of approximately 40 ppm styrene and 14 formers exposed to an average of about 10 ppm styrene. Ambient air monitoring data and the concentration of mandelic acid in the urine were used for the assessment of exposure. From each subject, peripheral blood lymphocytes were analysed for sister chromatid exchanges (SCEs). In the laminators, the mean SCE frequency was significantly higher than in the controls in both the group of smokers (9.59 ± 0.77 SCEs/cell vs 7.23 ± 1.00 SCEs/cell) and the group of non-smokers (10.25 ± 1.08 SCEs/cell vs 5.98 ± 0.60 SCEs/cell). The mean SCE frequency of the formers (7.42 ± 128 SCEs/cell in smokers) did not differ statistically from the controls (7.23 ± 1.00 SCEs/cell in smokers). No evaluation was made for non-smoking formers since all but one worker in this group were smokers. In order to comply with a lowering of the occupational exposure limit (MAK value) for occupational exposure to styrene in the Federal Republic of Germany from 100 ppm to 20 ppm, considerable technical and hygienic improvements were made at the work site of the laminators. This intervention led to a reduction of average exposure of these workers by inhalation from 40 ppm to approximately 20 ppm. One year after these improvements were made, a second investigation was performed. In all but one of the laminators, the concentration of mandelic acid in urine had dropped considerably. The SCE frequency in blood lymphocytes of the laminators had likewise dropped significantly to 7.74 ± 0.59 SCEs/cell in the non-smokers. In the smokers, it was also lower than on the first occasion (9.02 ± 1.19), yet statistical evaluation was not possible due to insufficient numbers. Overall, the results of the intervention study show that the lowering of the occupational exposure limit for styrene to 20 ppm in Germany was justified and that a reduction of occupational exposure to the chemical has led to a prevention of adverse cytogenetic effects. 相似文献
33.
The Physical Inactivity Matrix: Lessons from the classification of physical inactivity interventions
Kypros Kypri Alex Donaldson Elizabeth Johnstone 《Journal of Science and Medicine in Sport》2006,9(1-2):98-102
Physical inactivity (PI), a leading modifiable cause of disease and injury, is endemic in industrialised nations. Although considerable research has been undertaken in this field, we lack a system to synthesise the research literature to inform policy and identify research needs. The aims of this study were to (1) develop a system to classify physical inactivity intervention studies, (2) examine the distribution of PI interventions published in the peer-reviewed health literature using the system, and (3) consider implications for future research. We developed the Physical Inactivity Matrix (PIM), with 12 intervention points, created by the intersection of two dimensions: the intervention target (individual, physical environment and social/cultural environment) and the activity focus (transport, work/school, leisure and consumer). A formal search of the health research literature identified 529 eligible studies and each was classified into one of the 12 cells of the PIM. Most studies were categorised as: individual-leisure (68%), individual-work/school (12%) or social/cultural environment-leisure (13%). Only 4% targeted the physical environment. The findings of this initial application of the PIM support the call for greater investment in policies, interventions and research that focus on the relationship between the environment and PI, and transportation in particular. There would be merit in establishing the inter-rater reliability of the PIM and applying it to a wider variety of studies, including those published in the transportation and urban planning literatures. The PIM could be a useful tool for monitoring trends in research directions and funding levels over time and across countries. 相似文献
34.
目的:分析新生儿医院感染相关危险因素及干预对策.方法:通过对榆林市第一医院2006年5月至2010年5月收治的1428例住院新生儿医院感染发生情况.结果:新生儿患者医院感染率从2006年5月至2008年5月的3.20%,下降到2008年5月至2010年5月的1.99%.结论:对新生儿室医疗护理工作中各种医院感染相关危险因素采取相应的干预对策后,新生儿患者的医院感染率明显降低,提高了医疗护理质量. 相似文献
35.
福建省消除碘缺乏病综合干预策略与措施的研究 总被引:1,自引:0,他引:1
目的探讨福建省消除碘缺乏病的综合干预策略与措施。方法实施以盐田废转、目标人群健康教育和健康促进为主要干预措施的综合干预方法。结果实现了以省为单位消除碘缺乏病的目标:在项目的实施期间,福清市、同安区、华安县、石狮市、晋江市、平和县等项目县达到消除碘缺乏病标准;项目地区居民合格碘盐食用率大幅度提高;全省碘盐销量从1997年的9.8万吨提高到2005年的16.65万吨。结论消除碘缺乏病综合干预项目有力促进了福建省消除碘缺乏病的进程,提高了居民合格碘盐的食用率。 相似文献
36.
Philip M. Zeman Bernie C. Till Nigel J. Livingston James W. Tanaka Peter F. Driessen 《Clinical neurophysiology》2007,118(12):2591-2604
OBJECTIVE: To evaluate the effectiveness of a new method of using Independent Component Analysis (ICA) and k-means clustering to increase the signal-to-noise ratio of Event-Related Potential (ERP) measurements while permitting standard statistical comparisons to be made despite the inter-subject variations characteristic of ICA. METHODS: Per-subject ICA results were used to create a channel pool, with unequal weights, that could be applied consistently across subjects. Signals derived from this and other pooling schemes, and from unpooled electrodes, were subjected to identical statistical analysis of the N170 own-face effect in a Joe/No Joe face recognition paradigm wherein participants monitored for a target face (Joe) presented amongst other unfamiliar faces and their own face. Results between the Joe, unfamiliar face and own face conditions were compared using Cohen's d statistic (square root of signal-to-noise ratio) to measure effect size. RESULTS: When the own-face condition was compared to the Joe and unfamiliar-face conditions, the channel map method increased effect size by a factor ranging from 1.2 to 2.2. These results stand in contrast to previous findings, where conventional pooling schemes failed to reveal an N170 effect to the own-face stimulus (Tanaka JW, Curran T, Porterfield A, Collins D. The activation of pre-existing and acquired face representations: the N250 ERP as an index of face familiarity. J Cogn Neurosci 2006;18:1488-97). Consistent with conventional pooling schemes, the channel map approach showed no reliable differences between the Joe and Unfamiliar face conditions, yielding a decrease in effect size ranging from 0.13 to 0.75. CONCLUSIONS: By increasing the signal-to-noise ratio in the measured waveforms, the channel pool method demonstrated an enhanced sensitivity to the neurophysiological response to own-face relative to other faces. SIGNIFICANCE: By overcoming the characteristic inter-subject variations of ICA, this work allows classic ERP analysis methods to exploit the improved signal-to-noise ratio obtainable with ICA. 相似文献
37.
海南省黎族中学生艾滋病知识干预效果分析 总被引:3,自引:0,他引:3
目的:通过干预提高黎族中学生的艾滋病知识水平,降低黎族人群感染艾滋病的危险。方法:采用集中授课、播发VCD等方式进行干预,利用自行设计的调查表对干预对象进行相关知识调查。结果:干预后中学生对艾滋病相关知识的认识均有不同程序的提高,最高提高22.90个百分点,最低提高6.50个百分点,平均提高15.46个百分点;艾兹病知识主要来源于电视广播和医生,分别占58.00%和22.00%。结论:在黎族中学生中开展艾滋病健康教育是完全可行且是十分必要的,应该引起重视。 相似文献
38.
Hailong Tao Jianzeng Dong Ronghui Yu Changsheng Ma 《Journal of interventional cardiac electrophysiology》2007,19(1):41-43
Straight back syndrome (SBS) is a thoracic deformity with absence of upper thoracic spine kyphosis and heart compression.
The anatomic abnormity of SBS may raise the difficulty of introcardial operation and increase the complicated risk of intervention
performance. Here we report a case of SBS with complicated transseptal puncture during intervention catheter ablation of atrial
fibrillation. 相似文献
39.
目的探讨围手术期患者的心理状态及干预措施。方法对2009年1月至2010年1月间在我院接受手术治疗的患者92进行心理评估,分析心理状态及干预措施。结果6项心理测试中得0分者以焦虑最多,恐惧次之,再次为孤独、抑郁、疼痛及依赖等因子。本组0~4分者占9.8%,5~8分者占79.3%,9~11分者占10.9%,无0分及无满分者。结论围手术期患者均存在一定的心理问题,需及时给予心理干预措施。 相似文献
40.
目的观察鸡精用于产后乳汁分泌的临床效果。方法产后每日早晚各服白兰氏鸡精70ml,共服3d,并与对照组、中药材催乳组对比。结果鸡精有促进早泌乳与增加泌乳量的作用。结论鸡精用于产妇有滋养身体,恢复产妇体力,促进早泌乳和增加泌乳量的作用,且饮用方便,效果好,无不良反应。 相似文献