全文获取类型
收费全文 | 17094篇 |
免费 | 1061篇 |
国内免费 | 58篇 |
专业分类
耳鼻咽喉 | 335篇 |
儿科学 | 397篇 |
妇产科学 | 597篇 |
基础医学 | 2756篇 |
口腔科学 | 375篇 |
临床医学 | 2240篇 |
内科学 | 2709篇 |
皮肤病学 | 449篇 |
神经病学 | 1624篇 |
特种医学 | 1062篇 |
外科学 | 2125篇 |
综合类 | 165篇 |
一般理论 | 2篇 |
预防医学 | 864篇 |
眼科学 | 535篇 |
药学 | 1082篇 |
中国医学 | 19篇 |
肿瘤学 | 877篇 |
出版年
2023年 | 84篇 |
2022年 | 97篇 |
2021年 | 177篇 |
2020年 | 144篇 |
2019年 | 206篇 |
2018年 | 303篇 |
2017年 | 279篇 |
2016年 | 375篇 |
2015年 | 400篇 |
2014年 | 457篇 |
2013年 | 549篇 |
2012年 | 887篇 |
2011年 | 841篇 |
2010年 | 611篇 |
2009年 | 609篇 |
2008年 | 733篇 |
2007年 | 844篇 |
2006年 | 883篇 |
2005年 | 885篇 |
2004年 | 819篇 |
2003年 | 735篇 |
2002年 | 772篇 |
2001年 | 368篇 |
2000年 | 282篇 |
1999年 | 320篇 |
1998年 | 304篇 |
1997年 | 283篇 |
1996年 | 259篇 |
1995年 | 222篇 |
1994年 | 172篇 |
1993年 | 152篇 |
1992年 | 159篇 |
1991年 | 174篇 |
1990年 | 161篇 |
1989年 | 187篇 |
1988年 | 187篇 |
1987年 | 137篇 |
1986年 | 131篇 |
1985年 | 153篇 |
1984年 | 131篇 |
1983年 | 97篇 |
1982年 | 90篇 |
1981年 | 98篇 |
1980年 | 85篇 |
1979年 | 114篇 |
1978年 | 98篇 |
1977年 | 103篇 |
1976年 | 90篇 |
1975年 | 91篇 |
1972年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Werner Spileers Guy A. Orban Hugo Maes Luc Missotten 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):363-374
CMSS-VEPs are presented as a sensitive, non-invasive functional investigation technique of the visual function, applicable in clinical practice. New improvements of the technique are presented. The underlying neuronal mechanisms are discussed. The clinical use is illustrated in a case of optic neuritis. 相似文献
62.
Selective laser trabeculoplasty in phakic and pseudophakic eyes. 总被引:2,自引:0,他引:2
BACKGROUND AND OBJECTIVE: To evaluate the effect of pseudophakia on the success of selective laser trabeculoplasty in lowering intraocular pressure (IOP). PATIENTS AND METHODS: In this retrospective, nonrandomized clinical trial, a chart review of all patients who underwent selective laser trabeculoplasty from September 2002 to June 2004 using a frequency-doubled Q-switched 532-nm Nd:YAG laser was performed. Changes in IOP and statistical significance were determined at each follow-up period. Average decrease in IOP and success rates for phakic and pseudophakic eyes were compared statistically at each time period. RESULTS: In the phakic group, mean IOP decreased from 18.1 to 15.5 mm Hg (P < .0005) and mean glaucoma medication use decreased from 2.1 to 1.6 medications after 24 months of follow-up. In the pseudophakic group, mean IOP decreased from 18.3 to 15.2 mm Hg (P < .005) and mean glaucoma medication use decreased from 2.2 to 1.6 medications. Success rates ranged from 54% to 67% in the phakic group and 52% to 65% in the pseudophakic group. No statistically significant difference between phakic and pseudophakic eyes in decreased IOP or success rates was seen at any time point (P > .05). No significant complications occurred in either group. CONCLUSIONS: Selective laser trabeculoplasty is effective in lowering IOP in both phakic and pseudophakic patients. 相似文献
63.
64.
Spectral sensitivity was measured for nine infants, 4-6 weeks of age, and three adults under conditions of chromatic adaptation chosen to reveal the presence of short-wavelength-sensitive cones. Monochromatic test stimuli (400-550 nm) were presented at 2 Hz superimposed on a broadband, yellow background. Following 4 min of adaptation to the background, test stimuli were presented while recording the steady-state, visually-evoked cortical potential (VECP). Response averages were obtained for several radiance levels at each test wavelength, and the amplitude of the fundamental frequency was extracted from the digitized response with a fast-Fourier transform. These data were used to construct response vs intensity functions for each wavelength. A fixed criterion response was chosen from the latter family of functions to generate individual spectral sensitivity curves. These VECP spectral sensitivity functions matched the psychophysically-determined functions of adults, measured by the method of adjustment and with the same stimulus configuration. Peak sensitivity for infants and adults under these conditions occurred at about 440 nm, and the main lobe of the curve (400-500 nm) was well fitted by the Vos-Walraven short-wavelength cone fundamental. The only major difference between the infant and adult data was in the relative sensitivity of the secondary mode of the curves (above 500 nm). These results demonstrate the presence of short-wavelength-sensitive cones and a functional pathway to the visual cortex by 4-6 weeks of age. 相似文献
65.
Wolfgang Werner 《Archiv der Pharmazie》1990,323(12):955-956
66.
Barbara Resnick Denise Orwig Janet Yu-Yahiro William Hawkes Michelle Shardell J. Richard Hebel Sheryl Zimmerman Justine Golden Michele Werner Jay Magaziner 《Annals of behavioral medicine》2007,34(1):67-76
Background: Exercise is an important strategy with potential to improve recovery in older adults following a hip fracture.Purpose: The purpose of this study was to test the impact of a self-efficacy based intervention, the Exercise Plus Program, and the
different components of the intervention, on self-efficacy, outcome expectations, and exercise behavior among older women
post-hip fracture.Methods: Participants were randomized to one of four groups: exercise plus, exercise only, plus only (i.e., motivation), or routine
care. Data collection was done at baseline (within 22 days of fracture), 2, 6, and 12 months post-hip fracture.Results: A total of 209 women were recruited with an average age of 81.0 years (SD=6.9). The majority was White (97.1%), was widowed
(57.2%), and had a high school education (66.7%). Generalized Estimating Equations were used to perform repeated measures
analyses. No differences in trajectories of recovery were observed for self-efficacy or outcome expectations. A statistically
significant difference in the overall trajectory of time in exercise was seen (p<.001), with more time spent exercising in
all three treatment groups.Conclusions: The study demonstrated that it was possible to engage these women in a home-based exercise program and that the plus only,
exercise only, and the exercise plus groups all increased exercise.
Support for this project was provided by National Institute on Aging grants R37 AG09901, R01-AG18668, R01 AG17082, and the
Claude D. Pepper Older Americans Independence Center P60-AG12583. 相似文献
67.
Susan Kirk MSc BNurs RGN RM RHV DNCert Caroline Carlisle MSc BA RGN RM DNCert DipCouns RNT Karen A. Luker PhD BNurs RGN RHV DNCert 《Journal of advanced nursing》1997,26(5):1036-1044
A national study was conducted between 1991 and 1994 to explore and describe the changing role of the nurse teacher following the introduction of Project 2000 pre-registration nursing courses. Multiple methods were used to collect data from a wide variety of respondents (nurse teachers, midwife teachers, clinical nurses, health service managers and higher education lecturers). This paper presents the findings relating to the impact of Project 2000 and the move into higher education on the continuing educational needs of nurse teachers. Views on college strategies for staff development, the changing nature of teachers'academic and professional development needs and the problems of the conflicting demands experienced are reported. The research highlights the need for clinical credibility to be clearly defined in relation to nurse teachers and for educational institutions to place more emphasis on teachers'clinical development if the rhetoric of policy is to become a reality. 相似文献
68.
Christoph Scherfler MD Johannes Schwarz MD PhD Angelo Antonini MD PhD Donald Grosset MD Francesc Valldeoriola MD PhD Kenneth Marek MD Wolfgang Oertel MD Eduardo Tolosa MD PhD Andrew J. Lees MD Werner Poewe MD 《Movement disorders》2007,22(9):1229-1238
The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society 相似文献
69.
Genetic engineering provides the opportunity for the synthesis of human proteins and derivatives thereof which are of significant value for replacement therapy. However, in addition to genetic engineering an extensive process development has to be carried out in order to establish an economic production process and to guarantee consistently high product quality from batch to batch. This includes the characterization of the production host cell vector construct, the validation of the fermentation and the protein purification process as well as the lyophilization and the reconstitution of the final product. A number of in-process and final product controls have to be established and limits for the specification have to be elaborated to provide consistent product quality. Real time stability data have to be supplied because data from accelerated conditions do not allow extrapolation of the shelf life of proteins. Data obtained from process development and validation of the production process contributes to the preparation of the chemical pharmaceutical dossier and the expert report to be submitted to the regulatory authorities. 相似文献
70.