全文获取类型
收费全文 | 232篇 |
免费 | 15篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 11篇 |
妇产科学 | 1篇 |
基础医学 | 23篇 |
口腔科学 | 9篇 |
临床医学 | 55篇 |
内科学 | 56篇 |
皮肤病学 | 5篇 |
神经病学 | 16篇 |
特种医学 | 26篇 |
外科学 | 41篇 |
综合类 | 14篇 |
预防医学 | 3篇 |
药学 | 19篇 |
肿瘤学 | 7篇 |
出版年
2022年 | 2篇 |
2020年 | 5篇 |
2019年 | 4篇 |
2017年 | 3篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 5篇 |
2013年 | 4篇 |
2012年 | 4篇 |
2011年 | 6篇 |
2010年 | 8篇 |
2009年 | 9篇 |
2008年 | 4篇 |
2007年 | 39篇 |
2006年 | 7篇 |
2005年 | 16篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 6篇 |
2000年 | 2篇 |
1999年 | 9篇 |
1998年 | 11篇 |
1997年 | 14篇 |
1996年 | 14篇 |
1995年 | 6篇 |
1994年 | 8篇 |
1993年 | 6篇 |
1991年 | 2篇 |
1990年 | 4篇 |
1989年 | 8篇 |
1988年 | 3篇 |
1987年 | 4篇 |
1986年 | 4篇 |
1985年 | 5篇 |
1984年 | 4篇 |
1983年 | 3篇 |
1981年 | 3篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1975年 | 3篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1969年 | 1篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1965年 | 3篇 |
1934年 | 1篇 |
排序方式: 共有291条查询结果,搜索用时 15 毫秒
81.
Intraoperative blood salvage: a review 总被引:3,自引:0,他引:3
82.
Various inventories have been developed to quantify the success of hearing aid provision. Though numerous parameters including initial measures (hearing disability, handicap) or 'outcome measures' (e.g. benefit, satisfaction and usage) are recorded, relationships and interactions among them are still unclear. A study applying a questionnaire addressing 11 domains relevant to amplification was conducted in order to generate different psychometric models with the AMOS software package for structural equation modeling. The models expose easily interpretable interactions and are helpful in understanding effects occurring with commonly used outcome measures: benefit reflects the difference between the aided and unaided condition but additionally comprises the importance of the hearing aid within a specific situation. Satisfaction is highly reliant on benefit. Usage is strongly dependent on the severity of hearing problems and therefore not appropriate in assessing the success of amplification. Moreover, the models help to predict the outcome of clinically used inventories (i.e. the Glasgow Hearing Aid Benefit Profile). 相似文献
83.
Lausberg H. D. Bolte Beer N. Matussek Kiese D. Gericke R. Hild E. Frick Gallitz 《Journal of molecular medicine (Berlin, Germany)》1971,49(12):713-715
Ohne Zusammenfassung 相似文献
84.
50 years of research on killed or live vaccine
for schistosomiasis without successful produc-
tion of a human schistosomiasis vaccine are
reviewed. 相似文献
85.
86.
OBJECTIVE: To introduce conjoint analysis (CA) as a method to explain choice decisions of hearing aid users and to measure the contributions of different hearing aid attributes involved. DESIGN: The study was conducted using CA, a method that is well established in marketing, but has not been used for hearing aid research. CA examines the contributions (importance) various attributes make to overall preference judgements. It is based on the premises that objects (i.e., hearing aids) can be described as different combinations of several attributes. The relative importance of the attributes is estimated from integral judgements of hypothetical hearing aids. The advantages of CA are a more realistic presentation of complete products instead of isolated attributes and the consideration of trade-offs between the features. The following attributes selected from 12 features in a prestudy were included in the application: speech perception in quiet, speech perception in noise, handling, sound quality, localization, and feedback. 93 randomly chosen experienced hearing aid wearers participated in the survey. RESULTS: It was found that the attributes concerning speech perception were by far most important. Speech discrimination in quiet and in noise were almost equally significant and contributed with 56% to the preference decisions of the subjects. The remaining attributes showed values in the range of 10% to 12%. When comparing various subgroups dependent on age, sex, hearing loss, satisfaction, etc., significant differences concerning the preferences were found. Elder and female subjects attached greater importance of the attribute "handling" whereas younger patients judged "speech in noise" more important. In general, subjects with greater hearing loss considered speech intelligibility in quiet to be more important than in noisy surroundings. Moreover, sound quality seems to be a significant indicator for satisfaction with the hearing aid. CONCLUSIONS: This study proposes CA as a survey technique to examine individual preferences for hearing aids. Several assumptions about the importance of hearing aid features for different groups of users could be confirmed quantitatively. Segmentation showed valid results depending on socio-demographic and user-specific parameters. The method used and the results are of interest for audiologists as well as the hearing aid industry. They provide valuable tools for future hearing aid design and should be considered in the development of self-assessment inventories. 相似文献
87.
I. Helmich H. Lausberg 《Experimental brain research. Experimentelle Hirnforschung. Expérimentation cérébrale》2014,232(10):3159-3173
The present study addresses the previously discussed controversy on the contribution of the right and left cerebral hemispheres to the production and conceptualization of spontaneous hand movements and gestures. Although it has been shown that each hemisphere contains the ability to produce hand movements, results of left hemispherically lateralized motor functions challenge the view of a contralateral hand movement production system. To examine hemispheric specialization in hand movement and gesture production, ten right-handed participants were tachistoscopically presented pictures of everyday life actions. The participants were asked to demonstrate with their hands, but without speaking what they had seen on the drawing. Two independent blind raters evaluated the videotaped hand movements and gestures employing the Neuropsychological Gesture Coding System. The results showed that the overall frequency of right- and left-hand movements is equal independent of stimulus lateralization. When hand movements were analyzed considering their Structure, the presentation of the action stimuli to the left hemisphere resulted in more hand movements with a phase structure than the presentation to the right hemisphere. Furthermore, the presentation to the left hemisphere resulted in more right and left-hand movements with a phase structure, whereas the presentation to the right hemisphere only increased contralateral left-hand movements with a phase structure as compared to hand movements without a phase structure. Gestures that depict action were primarily displayed in response to stimuli presented in the right visual field than in the left one. The present study shows that both hemispheres possess the faculty to produce hand movements in response to action stimuli. However, the left hemisphere dominates the production of hand movements with a phase structure and gestures that depict action. We therefore conclude that hand movements with a phase structure and gestures that represent action stem from a left hemispheric system of conceptualization. 相似文献
88.
To evaluate the separation efficiency of Ericsson's two- and three- layer
albumin separation methods, semen samples from 21 healthy males were
studied. Seven patients already had two or more sons, another seven had two
or more daughters and the other seven had primary infertility due to female
factors. The semen samples were divided into three aliquots: one remained
unprocessed initially, the other two aliquots went through two- and
three-layer albumin separation methods respectively. All samples were then
stained with X-Y double staining probes. In each group, four or five
samples were processed at room temperature, and two or three at body
temperature (37 degrees C). The labelling efficiency of X-Y double staining
probe was over 99%. The X:Y sperm ratios were even in the original samples.
The ratios of the X and Y spermatozoa were altered slightly but
significantly after the two- layer (P < or = 0.05) or the three-layer (P
< or = 0.005) separation. The alterations occurred only at room
temperature. The X spermatozoa increased and the Y spermatozoa decreased,
both to a small degree of difference (1.4-3.5%). Double fluorescence
in-situ hybridization analysis therefore showed that albumin separation
methods do not enrich Y spermatozoa.
相似文献
89.
Neutrophil-specific granule deficiency includes eosinophils 总被引:2,自引:0,他引:2
90.
Ultrasonographic B-mode images were obtained at various exposure levels with three real-time diagnostic scanners. Adult human and tissue-equivalent phantom images were compared in terms of diagnostic content and depth of penetration. For the exposure level settings used, spatial-peak pulse-average intensities ranged from approximately 10 to 500 W/cm2. At the 3.50-3.75-MHz nominal frequencies used in the study, images of the human abdomen showed little discernible change in quality with varying exposure levels. However, phantom tests confirmed that depth of penetration is a function of exposure level. The results suggest that a judicious use of exposure level and receiver gain controls can be a practical means for minimizing patient exposure to ultrasound without sacrifice of diagnostic effectiveness. 相似文献