全文获取类型
收费全文 | 1375篇 |
免费 | 94篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 14篇 |
儿科学 | 55篇 |
妇产科学 | 75篇 |
基础医学 | 182篇 |
口腔科学 | 21篇 |
临床医学 | 120篇 |
内科学 | 208篇 |
皮肤病学 | 14篇 |
神经病学 | 257篇 |
特种医学 | 25篇 |
外科学 | 116篇 |
综合类 | 11篇 |
一般理论 | 2篇 |
预防医学 | 61篇 |
眼科学 | 166篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 96篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 25篇 |
2021年 | 56篇 |
2020年 | 41篇 |
2019年 | 58篇 |
2018年 | 69篇 |
2017年 | 50篇 |
2016年 | 50篇 |
2015年 | 44篇 |
2014年 | 57篇 |
2013年 | 77篇 |
2012年 | 98篇 |
2011年 | 116篇 |
2010年 | 49篇 |
2009年 | 59篇 |
2008年 | 88篇 |
2007年 | 74篇 |
2006年 | 82篇 |
2005年 | 66篇 |
2004年 | 54篇 |
2003年 | 47篇 |
2002年 | 37篇 |
2001年 | 6篇 |
2000年 | 8篇 |
1999年 | 5篇 |
1998年 | 18篇 |
1997年 | 7篇 |
1996年 | 12篇 |
1995年 | 10篇 |
1994年 | 9篇 |
1993年 | 8篇 |
1992年 | 11篇 |
1991年 | 7篇 |
1990年 | 8篇 |
1989年 | 2篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 9篇 |
1985年 | 2篇 |
1984年 | 7篇 |
1983年 | 5篇 |
1982年 | 8篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有1473条查询结果,搜索用时 39 毫秒
11.
Amos D. Korczyn Eitan Auriel Ludmila Shopin Hen Hallevi Shani Shenhar‐Tsarfaty Anat Mike Moran Artzi Ilana Klovatch Natan M. Bornstein Dafna Ben Bashat 《Hippocampus》2016,26(2):161-169
The hippocampus is known to play a vital role in learning and memory and was demonstrated as an early imaging marker for Alzheimer's disease (AD). However, its role as a predictor for mild cognitive impairment and dementia following stroke is unclear. The main purpose of this study was to examine the associations between hippocampal volume, mean diffusivity (MD) and connectivity and cognitive state following stroke. Eighty three consecutive first ever mild to moderate stroke or transient ischemic attack (TIA) survivors from our ongoing prospective TABASCO (Tel Aviv Brain Acute Stroke Cohort) study underwent magnetic resonance imaging scans within 7 days of stroke onset. Hippocampal volume was measured from T1 weighted images, hippocampal mean diffusivity was calculated from diffusion tensor imaging and connectivity was calculated from resting state fMRI. Global cognitive assessments were evaluated during hospitalization and 6 and 12 months later using a computerized neuropsychological battery. Multiple linear regression analysis was used to test which of the hippocampi measurements best predict cognitive state. All three imaging parameters were significantly correlated to each other (|r's| >0.3, P's < 0.005), and with cognitive state 6 and 12 months after the event. Multiple regression analyses demonstrated the predictive role of hippocampal mean diffusivity (β = ?0.382, P = 0.026) on cognitive state, above and beyond that of volume and connectivity of this structure. To our knowledge, the combination of hippocampal volume, mean diffusivity and connectivity in first ever post stroke or TIA patients has not yet been considered in relation to cognitive state. The results demonstrate the predictive role of hippocampal mean diffusivity, suggesting that these changes may precede and contribute to volumetric and connectivity changes in the hippocampi, potentially serving as a marker for early identification of patients at risk of developing cognitive impairment or dementia. © 2015 Wiley Periodicals, Inc. 相似文献
12.
OBJECT: The goal of this study was to study the influence of sex and age on factors affecting patient outcome in severe head injury. METHODS: Data from the prospectively conducted international trial of tirilazad mesylate in patients with head injury were analyzed retrospectively. Included were 957 patients, 23% of whom were female and all of whom were between the ages of 15 and 79 years. All patients presented with Glasgow Coma Scale (GCS) scores between 3 and 8 and evidence of structural brain damage and/or subarachnoid hemorrhage (SAH) on the initial CT scan. Frequencies of recognized risk factors, including brain swelling, intracranial hypertension, systemic hypotension, advanced age, SAH, and injury severity (based on GCS scores), as well as dichotomized Glasgow Outcome Scale (GOS) scores (good recovery or moderate disability compared with severe disability, persistent vegetative state, or death) obtained 6 months postinjury were compared between male and female patients. CONCLUSIONS: Overall significantly greater frequencies of brain swelling and intracranial hypertension were found in female compared with male patients (35% compared with 24% [p < 0.0008] and 39 compared with 31% [p < 0.03], respectively). The highest rates were found in female patients younger than 51 years old (38% compared with 24% [p < 0.002] and 40% compared with 30% [p < 0.02], respectively, in male patients younger than 51 years of age). This effect was independent of injury severity (GCS) scores, which were not different in male and female patients. Female patients younger than 50 years tended to have worse outcomes, but the difference was not statistically significant. Thus, female patients who sustain severe head injury, especially (presumably) premenopausal ones aged 50 years and younger, are significantly more likely to experience brain swelling and intracranial hypertension than male patients with a comparable injury severity, suggesting that younger women may benefit from more aggressive monitoring and treatment of intracranial hypertension. 相似文献
13.
14.
Kehat R Zemel E Cuenca N Evron T Toiber D Loewenstein A Soreq H Perlman I 《Investigative ophthalmology & visual science》2007,48(3):1290-1297
PURPOSE: To study the involvement of stress-induced acetylcholinesterase (AChE) expression in light-induced retinal damage in albino rats. METHODS: Adult albino rats were exposed for 24 hours to bright, damaging light. AChE expression was monitored by in situ hybridization, by histochemistry for AChE activity, and by immunocytochemistry. An orphan antisense agent (Monarsen; Ester Neurosciences, Ltd., Herzlia Pituach, Israel) was administered intraperitoneally to minimize light-induced AChE expression. The electroretinogram (ERG) was recorded to assess retinal function. RESULTS: Twenty-four-hour exposure to bright light caused severe reduction in the ERG responses and augmented expression of mRNA for the "read-through" variant of AChE (AChE-R) in photoreceptor inner segments (IS), bipolar cells, and ganglion cells. AChE activity increased in IS. The expressed AChE protein was a novel variant, characterized by an extended N terminus (N-AChE). Systemic administration of the orphan antisense agent, Monarsen, reduced the photic induction of mRNA for AChE-R, and of the N-AChE protein. Rats exposed to bright, damaging light and treated daily with Monarsen exhibited larger ERG responses, relatively thicker outer nuclear layer (ONL), and more ONL nuclei than did rats exposed to the same damaging light but treated daily with saline. CONCLUSIONS: The findings indicate that the photic-induced novel variant of AChE (N-AChE-R) may be causally involved with retinal light damage and suggest the use of RNA targeting for limiting such damage. 相似文献
15.
16.
Brasil OF Smith SD Galor A Lowder CY Sears JE Kaiser PK 《The British journal of ophthalmology》2007,91(6):761-765
AIM: To evaluate the predictive factors for visual outcome after intravitreal triamcinolone acetonide injection to treat refractory diabetic macular oedema (DME). METHODS: A retrospective chart review of patients with DME who met the following inclusion criteria was performed: clinically significant diabetic macular oedema, receipt of a 4 mg/0.1 ml intravitreal triamcinolone acetonide injection and an optical coherence tomography (OCT) of the macula performed up to 10 days before injection. All patients received a full ophthalmic examination including best-corrected Snellen visual acuity (VA). The main outcome measure was the mean change in vision 3 months after injection. RESULTS: Data from 73 eyes of 59 patients were analysed. After a mean follow-up of 324 days, the mean change in vision was -0.075 logarithm of minimum angle of resolution (logMAR) units, with 27.3% improving > or =3 lines, 6.8% declining > or =3 lines and 60.2% remaining stable within 1 line of baseline vision. Statistical analysis was performed using multivariate generalised estimating equations on the basis of data from 52 eyes of 42 patients. Factors associated with an improvement in vision 3 months after injection were worse baseline VA (-0.27 logMAR units/unit increase in baseline VA, p = 0.002) and presence of subretinal fluid (-0.17 logMAR units, p = 0.06). The presence of cystoid macular oedema negatively affected the visual outcome (0.15 logMAR units, p = 0.03). In addition, the presence of an epiretinal membrane (ERM) was associated with less visual improvement. ERM modified the effect of baseline VA as demonstrated by a significant interaction between these two variables (0.34 logMAR units/unit increase in baseline VA, p = 0.04). CONCLUSIONS: OCT factors and baseline VA can be useful in predicting the outcomes of VA 3 months after intravitreal triamcinolone acetonide injection in patients with refractory DME. 相似文献
17.
Yoav Michowitz Anat Milman Antoine Andorin Georgia Sarquella-Brugada M. Cecilia Gonzalez Corcia Jean-Baptiste Gourraud Giulio Conte Frederic Sacher Jimmy J.M. Juang Sung-Hwan Kim Eran Leshem Philippe Mabo Pieter G. Postema Aviram Hochstadt Yanushi D. Wijeyeratne Isabelle Denjoy Carla Giustetto Yuka Mizusawa Bernard Belhassen 《Journal of the American College of Cardiology》2019,73(14):1756-1765
Background
Information on young patients with Brugada syndrome (BrS) and arrhythmic events (AEs) is limited.Objectives
The purpose of this study was to describe their characteristics and management as well as risk factors for AE recurrence.Methods
A total of 57 patients (age ≤20 years), all with BrS and AEs, were divided into pediatric (age ≤12 years; n = 26) and adolescents (age 13 to 20 years; n = 31).Results
Patients’ median age at time of first AE was 14 years, with a majority of males (74%), Caucasians (70%), and probands (79%) who presented as aborted cardiac arrest (84%). A significant proportion of patients (28%) exhibited fever-related AE. Family history of sudden cardiac death (SCD), prior syncope, spontaneous type 1 Brugada electrocardiogram (ECG), inducible ventricular fibrillation at electrophysiological study, and SCN5A mutations were present in 26%, 49%, 65%, 28%, and 58% of patients, respectively. The pediatric group differed from the adolescents, with a greater proportion of females, Caucasians, fever-related AEs, and spontaneous type-1 ECG. During follow-up, 68% of pediatric and 64% of adolescents had recurrent AE, with median time of 9.9 and 27.0 months, respectively. Approximately one-third of recurrent AEs occurred on quinidine therapy, and among the pediatric group, 60% of recurrent AEs were fever-related. Risk factors for recurrent AE included sinus node dysfunction, atrial arrhythmias, intraventricular conduction delay, or large S-wave on ECG lead I in the pediatric group and the presence of SCN5A mutation among adolescents.Conclusions
Young BrS patients with AE represent a very arrhythmogenic group. Current management after first arrhythmia episode is associated with high recurrence rate. Alternative therapies, besides defibrillator implantation, should be considered. 相似文献18.
19.
Livneh Nir Braeken Dionne Drozdinsky Genady Gafter-Gvili Anat Seelig Jaap Rozovski Uri Berger Tamar Raanani Pia Falanga Anna ten Cate Hugo Spectre Galia Leader Avi 《Journal of thrombosis and thrombolysis》2021,52(2):590-596
Journal of Thrombosis and Thrombolysis - Managing anticoagulation in hematological malignancy patients with atrial fibrillation and thrombocytopenia is a clinical challenge with limited data. We... 相似文献
20.
Cost Katherine T. Zaidman-Zait Anat Mirenda Pat Duku Eric Zwaigenbaum Lonnie Smith Isabel M. Ungar Wendy J. Kerns Connor Bennett Theresa Szatmari Peter Georgiades Stelios Waddell Charlotte Elsabbagh Mayada Vaillancourt Tracy 《Journal of autism and developmental disorders》2021,51(12):4575-4576
Journal of Autism and Developmental Disorders - 相似文献