全文获取类型
收费全文 | 21374篇 |
免费 | 1200篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 401篇 |
儿科学 | 490篇 |
妇产科学 | 460篇 |
基础医学 | 3612篇 |
口腔科学 | 439篇 |
临床医学 | 1973篇 |
内科学 | 3896篇 |
皮肤病学 | 528篇 |
神经病学 | 1970篇 |
特种医学 | 1135篇 |
外国民族医学 | 1篇 |
外科学 | 3194篇 |
综合类 | 147篇 |
一般理论 | 5篇 |
预防医学 | 1017篇 |
眼科学 | 683篇 |
药学 | 1433篇 |
中国医学 | 28篇 |
肿瘤学 | 1230篇 |
出版年
2022年 | 131篇 |
2021年 | 240篇 |
2020年 | 162篇 |
2019年 | 256篇 |
2018年 | 339篇 |
2017年 | 274篇 |
2016年 | 408篇 |
2015年 | 446篇 |
2014年 | 521篇 |
2013年 | 647篇 |
2012年 | 1141篇 |
2011年 | 1105篇 |
2010年 | 670篇 |
2009年 | 687篇 |
2008年 | 982篇 |
2007年 | 1106篇 |
2006年 | 1128篇 |
2005年 | 1158篇 |
2004年 | 1047篇 |
2003年 | 952篇 |
2002年 | 975篇 |
2001年 | 514篇 |
2000年 | 483篇 |
1999年 | 474篇 |
1998年 | 291篇 |
1997年 | 253篇 |
1996年 | 208篇 |
1995年 | 185篇 |
1994年 | 158篇 |
1993年 | 155篇 |
1992年 | 245篇 |
1991年 | 260篇 |
1990年 | 257篇 |
1989年 | 274篇 |
1988年 | 224篇 |
1987年 | 189篇 |
1986年 | 181篇 |
1985年 | 185篇 |
1984年 | 169篇 |
1983年 | 125篇 |
1982年 | 110篇 |
1981年 | 120篇 |
1979年 | 186篇 |
1978年 | 121篇 |
1977年 | 118篇 |
1976年 | 109篇 |
1975年 | 109篇 |
1974年 | 134篇 |
1973年 | 112篇 |
1972年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Werner Tolksdorf 《Schmerz (Berlin, Germany)》1988,2(2):105
Ohne Zusammenfassung 相似文献
62.
Christopher G Goetz Stanley Fahn Pablo Martinez-Martin Werner Poewe Cristina Sampaio Glenn T Stebbins Matthew B Stern Barbara C Tilley Richard Dodel Bruno Dubois Robert Holloway Joseph Jankovic Jaime Kulisevsky Anthony E Lang Andrew Lees Sue Leurgans Peter A LeWitt David Nyenhuis C Warren Olanow Olivier Rascol Anette Schrag Jeanne A Teresi Jacobus J Van Hilten Nancy LaPelle 《Movement disorders》2007,22(1):41-47
This article presents the revision process, major innovations, and clinimetric testing program for the Movement Disorder Society (MDS)-sponsored revision of the Unified Parkinson's Disease Rating Scale (UPDRS), known as the MDS-UPDRS. The UPDRS is the most widely used scale for the clinical study of Parkinson's disease (PD). The MDS previously organized a critique of the UPDRS, which cited many strengths, but recommended revision of the scale to accommodate new advances and to resolve problematic areas. An MDS-UPDRS committee prepared the revision using the recommendations of the published critique of the scale. Subcommittees developed new material that was reviewed by the entire committee. A 1-day face-to-face committee meeting was organized to resolve areas of debate and to arrive at a working draft ready for clinimetric testing. The MDS-UPDRS retains the UPDRS structure of four parts with a total summed score, but the parts have been modified to provide a section that integrates nonmotor elements of PD: I, Nonmotor Experiences of Daily Living; II, Motor Experiences of Daily Living; III, Motor Examination; and IV, Motor Complications. All items have five response options with uniform anchors of 0 = normal, 1 = slight, 2 = mild, 3 = moderate, and 4 = severe. Several questions in Part I and all of Part II are written as a patient/caregiver questionnaire, so that the total rater time should remain approximately 30 minutes. Detailed instructions for testing and data acquisition accompany the MDS-UPDRS in order to increase uniform usage. Multiple language editions are planned. A three-part clinimetric program will provide testing of reliability, validity, and responsiveness to interventions. Although the MDS-UPDRS will not be published until it has successfully passed clinimetric testing, explanation of the process, key changes, and clinimetric programs allow clinicians and researchers to understand and participate in the revision process. 相似文献
63.
Prof. Dr. Werner G. Daniel 《Herz》2007,32(2):87-88
Ohne Zusammenfassung 相似文献
64.
Christian Etz Henryk Welp Hans H Scheld Christof Schmid 《European journal of cardio-thoracic surgery》2005,27(4):722-723
We report on an unusual case of a young female patient who received an implantable LVAD after unsuccessful emergency coronary bypass surgery following acute myocardial infarction. After LVAD placement, it became evident that the patient had been pregnant. She had to undergo gynaecological surgery during mechanical support to remove the deceased fetus. 相似文献
65.
Werner Adrian 《Clinical & experimental optometry》2003,86(3):179-182
Background: Field studies of the duration of fixation during daytime driving find that it is about 0.2 seconds on average. Thus, the time available to read traffic signs is often limited. There are other circumstances where time to read alphanumeric messages is limited. Data relating time of observation are needed for purposes of ergonomic design as the data available in the literature are limited and uncertain. Method: Visual acuity was measured using Landolt rings in negative contrast, which were presented on a computer screen with a background luminance of 32 cd/m2 for durations that varied between two and 0.02 seconds at three different contrasts. Resulte: Visual acuity depends on the log of the light dose reduced by a factor that may be related to absorption of the light by the eye media. For young observers, it was found that: VA = 0.57 (log C t) + 1.705, where C is the contrast and is expressed as δL/L, where δL is the difference between target and background luminances in cd/m2 and t is the observation time in seconds. Conclusion: This formula or the functions fitted to the data obtained can be used to calculate the increase in target size needed to allow for short observation times. 相似文献
66.
Jennifer C. Chen Katrina L. Schmid Brian Brown Marion H. Edwards Bibianna SY Yu John KF Lew 《Clinical & experimental optometry》2003,86(5):323-330
Purpose: Caucasian children with myopia have elevated response accommodative vergence to accommodation (AC/A) ratios. The purpose of this study was twofold: to determine if response AC/A ratios vary with refractive error and with myopic progression rate in Hong Kong Chinese children, and to determine the effect of beta‐adrenergic antagonism with topical timolol application on AC/A ratios. Methods: Thirty children aged eight to 12 years participated in the study. All refractive errors were corrected with spectacle lenses. Accommodative responses were measured using a Shin‐Nippon autorefractor and concurrent changes in vergence were assessed using a vertical prism and a Howell‐Dwyer card at three metres and 0.33 metre. Accommodative demand was altered using plus or minus two dioptre lenses and lens‐ and distance‐induced response AC/A ratios were calculated. Measurements were repeated 30 minutes after the instillation of topical timolol maleate (0.5 per cent). Results: AC/A ratios appeared higher in progressing myopic children but the difference was not statistically significant. Timolol application reduced accommodative convergence (AC) in the stable myopes (reduction = ‐3 ± 1.14A) but not in the emmetropes (0.69 ± 0.9P) or progressing myopes (0.16 ± 0.43A) and this difference between refractive groups was statistically s ignificant (F2,27= 3.766; P= 0.036). However, timolol did not produce a significant change in the accommodative response to positive or negative lenses or response AC/A ratios. Conclusions: We did not find that AC/A ratios in myopic Chinese children were elevated and therefore, it is unlikely that elevated AC/A ratios are responsible for the high levels of myopia that occur in Hong Kong. The finding that timolol reduced AC in the stable myopes suggests that the autonomic control of accommodative convergence in these children may be different from that in emmetropic children and those with progressing myopia. 相似文献
67.
Richard Werner Karsten Alfke Tobias Schaeffter Arya Nabavi H Maximilian Mehdorn Olav Jansen 《Magnetic resonance in medicine》2004,52(6):1443-1447
A new method for the selective spin labeling of left- or right-sided supplying arteries of the brain without the need for additional RF coils is demonstrated. A clinical 1.5 T scanner was used. The spatial selectivity of the labeling process is based on the limited coverage of the excitation field of a standard send/receive head coil together with an oblique positioning of the labeling plane. A computer simulation was used to optimize key labeling parameters under the condition of laminar flow. The validity of the computer model results was confirmed by MRI measurements with a flow model. For human studies, a double-inversion continuous arterial spin labeling (CASL) sequence was modified to allow for arbitrary positioning of the labeling plane. The obtained perfusion-weighted images showed a clear delineation of the perfusion territories of the selected arteries in the anterior circulation of the brain and good gray/white matter contrast. 相似文献
68.
P-A Krayenbuehl P Wiesli M Schmid C Schmid J A Ehses M Hersberger W Vetter G Schulthess 《Experimental and clinical endocrinology & diabetes》2007,115(5):322-326
BACKGROUND: Tumor necrosis factor (TNF)-alpha has pleiotropic effects in cytokine-mediated inflammation underlying atherogenesis. Activation of this inflammatory process is assumed to be different in diabetic and non-diabetic individuals. Previous studies in non-diabetic subjects showed no association between TNF-alpha -308G>A polymorphism and coronary artery disease. METHODS: Vascular complications and cytokine serum concentrations were assessed as a function of the TNF-alpha -308G>A polymorphism in 76 diabetic patients on low-dose aspirin. RESULTS: Of 76 adult diabetic patients, 18 (24%) carried the TNF-alpha -308A allele (17 AG, 1 AA) and 58 (76%) carried wild-type alleles (GG). Prevalence of macrovascular complications was 33% in TNF-alpha -308A allele carriers (AG+AA) and 78% in wild-type allele carriers (GG) (p<0.001). In contrast, prevalence of microvascular complications was 78% and 84%, respectively, and did not significantly differ between the study groups. TNF-alpha -308A allele carriers (AG+AA) compared to wild-type allele carriers (GG) had significantly lower median serum concentrations of hs-C-reactive protein (1.5 vs 2.9 mg/L, p=0.030), interleukin 1-beta (0.9 vs 1.2 ng/L, p=0.046), and interleukin-6 (3.6 vs 4.9 ng/L, p=0.023). In multiple regression analysis, the prevalence of macrovascular diabetic complications was significantly associated with TNF-alpha -308G>A polymorphism (p<0.001) and serum concentrations of HDL-cholesterol (p=0.007) while confounding effects of further variables were excluded. CONCLUSION: TNF-alpha -308G>A polymorphism modulates cytokine serum concentrations and macrovascular complications in diabetic patients on aspirin. Diabetic carriers of the TNF-alpha -308A allele might benefit more from a prophylaxis with low dose aspirin than non-carriers. 相似文献
69.
Neurons in the Primate Superior Colliculus are Active Before and During Arm Movements to Visual Targets 总被引:2,自引:0,他引:2
Wilfried Werner 《The European journal of neuroscience》1993,5(4):335-340
The activity of single neurons in the superior colliculus was recorded while a rhesus monkey made arm movements to visual targets located on a screen in front of him. It was found that the activity of a subpopulation of cells was clearly related to these arm movements. The neurons began to discharge either with the onset of the movement, during the movement period, or well before the onset of electromyogram (EMG) activity and movement, and could be active for the entire duration of EMG activity. While the discharge pattern of some of these'reach'neurons was not different for movements to different target positions, other cells showed graded changes in activity depending on the direction of movement. The peak discharge rate could rise to > 100 impulses/s. Some units received somatosensory input; other reach cells exhibited a visual response and/or presaccadic activity. It is likely that the primate superior colliculus is not only involved in the initiation and control of orientating movements of the eyes but also in reaching movements of the arms. 相似文献
70.
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