全文获取类型
收费全文 | 25093篇 |
免费 | 2546篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 229篇 |
儿科学 | 710篇 |
妇产科学 | 588篇 |
基础医学 | 3416篇 |
口腔科学 | 615篇 |
临床医学 | 2963篇 |
内科学 | 5248篇 |
皮肤病学 | 355篇 |
神经病学 | 2388篇 |
特种医学 | 964篇 |
外科学 | 3229篇 |
综合类 | 588篇 |
一般理论 | 15篇 |
预防医学 | 2572篇 |
眼科学 | 456篇 |
药学 | 2137篇 |
1篇 | |
中国医学 | 30篇 |
肿瘤学 | 1199篇 |
出版年
2021年 | 360篇 |
2019年 | 355篇 |
2018年 | 412篇 |
2017年 | 329篇 |
2016年 | 315篇 |
2015年 | 383篇 |
2014年 | 524篇 |
2013年 | 780篇 |
2012年 | 1119篇 |
2011年 | 1163篇 |
2010年 | 678篇 |
2009年 | 569篇 |
2008年 | 1006篇 |
2007年 | 1201篇 |
2006年 | 1098篇 |
2005年 | 1140篇 |
2004年 | 1000篇 |
2003年 | 1067篇 |
2002年 | 958篇 |
2001年 | 690篇 |
2000年 | 693篇 |
1999年 | 605篇 |
1998年 | 315篇 |
1997年 | 258篇 |
1996年 | 245篇 |
1995年 | 281篇 |
1994年 | 272篇 |
1993年 | 223篇 |
1992年 | 527篇 |
1991年 | 487篇 |
1990年 | 471篇 |
1989年 | 491篇 |
1988年 | 449篇 |
1987年 | 453篇 |
1986年 | 393篇 |
1985年 | 455篇 |
1984年 | 390篇 |
1983年 | 307篇 |
1982年 | 294篇 |
1981年 | 241篇 |
1980年 | 246篇 |
1979年 | 346篇 |
1978年 | 296篇 |
1977年 | 211篇 |
1976年 | 248篇 |
1975年 | 216篇 |
1974年 | 272篇 |
1973年 | 284篇 |
1972年 | 232篇 |
1971年 | 213篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Alan J. Zillich Pharm.D. Margie E. Snyder Pharm.D. Caitlin K. Frail Pharm.D. M.S. Julie L. Lewis M.B.A. Donny Deshotels B.S. Patrick Dunham B.S. Heather A. Jaynes R.N. M.S.N. Jason M. Sutherland Ph.D. 《Health services research》2014,49(5):1537-1554
Objective
To evaluate the effectiveness of a telephonic medication therapy management (MTM) service on reducing hospitalizations among home health patients.Setting
Forty randomly selected, geographically diverse home health care centers in the United States.Design
Two-stage, randomized, controlled trial with 60-day follow-up. All Medicare- insured home health care patients were eligible to participate. Twenty-eight consecutive patients within each care center were recruited and randomized to usual care or MTM intervention. The MTM intervention consisted of the following: (1) initial phone call by a pharmacy technician to verify active medications; (2) pharmacist-provided medication regimen review by telephone; and (3) follow-up pharmacist phone calls at day seven and as needed for 30 days. The primary outcome was 60-day all-cause hospitalization.Data Collection
Data were collected from in-home nursing assessments using the OASIS-C. Multivariate logistic regression modeled the effect of the MTM intervention on the probability of hospitalization while adjusting for patients’ baseline risk of hospitalization, number of medications taken daily, and other OASIS-C data elements.Principal Findings
A total of 895 patients (intervention n = 415, control n = 480) were block-randomized to the intervention or usual care. There was no significant difference in the 60-day probability of hospitalization between the MTM intervention and control groups (Adjusted OR: 1.26, 95 percent CI: 0.89–1.77, p = .19). For patients within the lowest baseline risk quartile (n = 232), the intervention group was three times more likely to remain out of the hospital at 60 days (Adjusted OR: 3.79, 95 percent CI: 1.35–10.57, p = .01) compared to the usual care group.Conclusions
This MTM intervention may not be effective for all home health patients; however, for those patients with the lowest-risk profile, the MTM intervention prevented patients from being hospitalized at 60 days. 相似文献992.
Associations between T1 white matter lesion volume and regional white matter microstructure in aging 下载免费PDF全文
Elizabeth C. Leritz Juli Shepel Victoria J. Williams Lewis A. Lipsitz Regina E. McGlinchey William P. Milberg David H. Salat 《Human brain mapping》2014,35(3):1085-1100
White matter lesions, typically manifesting as regions of signal intensity abnormality (WMSA) on MRI, increase in frequency with age. However, the role of this damage in cognitive decline and disease is still not clear, as lesion volume has only loosely been associated with clinical status. Diffusion tensor imaging (DTI) has been used to examine the quantitative microstructural integrity of white matter, and has applications in the examination of subtle changes to tissue that appear visually normal on conventional imaging. The primary goal of this study was to determine whether major macrostructural white matter damage, (total WMSA volume), is associated with microstructural integrity of normal appearing white matter, and if these macrostructural changes fully account for microstructural changes. Imaging was performed in 126 nondemented individuals, ages 43–85 years, with no history of cerebrovascular disease. Controlling for age, greater WMSA volume was associated with decreased fractional anisotropy (FA) in widespread brain regions. Patterns were similar for FA and radial diffusivity but in contrast, WMSA was associated with axial diffusivity in fewer areas. Age was associated with FA in several regions, and many of these effects remained even when controlling for WMSA volume, suggesting the etiology of WMSAs does not fully account for all age‐associated white matter deterioration. These results provide evidence that WMSA volume is associated with the integrity of normal‐appearing white matter. In addition, our results suggest that overt lesions may not account for the association of increasing age with decreased white matter tissue integrity. Hum Brain Mapp 35:1085–1100, 2014. © 2013 Wiley Periodicals, Inc. 相似文献
993.
Clifton L. Gooch MD Timothy J. Doherty MD PhD K. Ming Chan MD Mark B. Bromberg MD PhD Richard A. Lewis MD Dan W. Stashuk PhD Michael J. Berger MD PhD Michael T. Andary MD Jasper R. Daube MD 《Muscle & nerve》2014,50(6):884-893
Introduction: Numerous methods for motor unit number estimation (MUNE) have been developed. The objective of this article is to summarize and compare the major methods and the available data regarding their reproducibility, validity, application, refinement, and utility. Methods: Using specified search criteria, a systematic review of the literature was performed. Reproducibility, normative data, application to specific diseases and conditions, technical refinements, and practicality were compiled into a comprehensive database and analyzed. Results: The most commonly reported MUNE methods are the incremental, multiple‐point stimulation, spike‐triggered averaging, and statistical methods. All have established normative data sets and high reproducibility. MUNE provides quantitative assessments of motor neuron loss and has been applied successfully to the study of many clinical conditions, including amyotrophic lateral sclerosis and normal aging. Conclusions: MUNE is an important research technique in human subjects, providing important data regarding motor unit populations and motor unit loss over time. Muscle Nerve 50 : 884–893, 2014 相似文献
994.
David R Owen Qi Guo Nicola J Kalk Alessandro Colasanti Dimitra Kalogiannopoulou Rahul Dimber Yvonne L Lewis Vincenzo Libri Julien Barletta Joaquim Ramada-Magalhaes Aruloly Kamalakaran David J Nutt Jan Passchier Paul M Matthews Roger N Gunn Eugenii A Rabiner 《Journal of cerebral blood flow and metabolism》2014,34(6):989-994
Positron emission tomography (PET) targeting the 18 kDa translocator protein (TSPO) is used to quantify neuroinflammation. Translocator protein is expressed throughout the brain, and therefore a classical reference region approach cannot be used to estimate binding potential (BPND). Here, we used blockade of the TSPO radioligand [11C]PBR28 with the TSPO ligand XBD173, to determine the non-displaceable volume of distribution (VND), and hence estimate the BPND. A total of 26 healthy volunteers, 16 high-affinity binders (HABs) and 10 mixed affinity binders (MABs) underwent a [11C]PBR28 PET scan with arterial sampling. Six of the HABs received oral XBD173 (10 to 90 mg), 2 hours before a repeat scan. In XBD173-dosed subjects, VND was estimated via the occupancy plot. Values of BPND for all subjects were calculated using this VND estimate. Total volume of distribution (VT) of MABs (2.94±0.31) was lower than VT of HABs (4.33±0.29) (P<0.005). There was dose-dependent occupancy of TSPO by XBD173 (ED50=0.34±0.13 mg/kg). The occupancy plot provided a VND estimate of 1.98 (1.69, 2.26). Based on these VND estimates, BPND for HABs is approximately twice that of MABs, consistent with predictions from in vitro data. Our estimates of [11C]PBR28 VND and hence BPND in the healthy human brain are consistent with in vitro predictions. XBD173 blockade provides a practical means of estimating VND for TSPO targeting radioligands. 相似文献
995.
Previous studies suggest that dairy intake may be associated with reduced bone and muscle loss with aging, but there are limited data in the very old. We evaluated the association between intake of dairy foods and peripheral bone structure and muscle mass in 564 elderly women aged 80 to 92 (mean 84.7) years, who were participants of the Calcium Intake Fracture Outcome Study/CAIFOS Aged Extension Study (CAIFOS/CARES) cohort and attended the 10‐year follow‐up. Assessments included dairy consumption (milk, yogurt, and cheese) by a validated food frequency questionnaire, 15% tibia bone mass, area and volumetric bone mineral density (vBMD) by peripheral quantitative computed tomography (pQCT), and appendicular bone and skeletal muscle mass by dual‐energy X‐ray absorptiometry (DXA). Women were categorized according to tertiles of dairy intake: first tertile (≤1.5 servings/d), second tertile (1.5 to 2.2 servings/d) and third tertile (≥2.2 servings/d). Controlling for confounding factors, pQCT assessment at the 15% tibia showed that compared with those in the first tertile of dairy intake, women in the third tertile had 5.7% greater total bone mass (p = 0.005), principally because of an increase in cortical and subcortical bone mass (5.9%, p = 0.050), resulting in a 6.2% increase in total vBMD (p = 0.013). Trabecular but not cortical and subcortical vBMD was also higher (7.8%, p = 0.044). DXA assessment showed that women in the third tertile of dairy intake had greater appendicular bone mass (7.1%, p = 0.007) and skeletal muscle mass (3.3%, p = 0.014) compared with tertile 1. The associations with bone measures were dependent on dairy protein and calcium intakes, whereas the association with appendicular muscle mass was not totally dependent on dairy protein intake. Our results suggest a positive association of dairy intake with appendicular bone mineralization and muscle mass in elderly women. Because many fractures in this age group are of the appendicular skeleton often associated with falls, dairy intake may be a modifiable lifestyle factor contributing to healthy aging. © 2014 American Society for Bone and Mineral Research. 相似文献
996.
Fiona M. Lewis David J. Coman Maryanne Syrmis 《Early child development and care》2014,184(12):1787-1799
There are no known biomedical or genetic markers to identify which infants with galactosaemia (GAL) are most at risk of poor language skill development, yet pre-linguistic communicative ‘red flag’ behaviours are recognised as early identifiers of heightened vulnerability to impaired language development. We report on pre-linguistic development in two 18-month-old infants with GAL (one of each gender). Results identified the male as displaying significantly poorer pre-linguistic skills than both his matched peers and relative to the female infant with GAL, whose pre-linguistic skills were commensurate with or better than her matched peers. The results suggest that by 18 months of age, differential developmental language skills can be identified in infants with GAL when the focus is on pre-linguistic communication behaviours. 相似文献
997.
998.
Jack Goldberg Kathryn M. Magruder Christopher W. Forsberg Lewis E. Kazis T. Bedirhan Üstün Matthew J. Friedman Brett T. Litz Viola Vaccarino Patrick J. Heagerty Theresa C. Gleason Grant D. Huang Nicholas L. Smith 《Quality of life research》2014,23(5):1579-1591
Purpose
To assess the relationship of posttraumatic stress disorder (PTSD) with health functioning and disability in Vietnam-era Veterans.Methods
A cross-sectional study of functioning and disability in male Vietnam-era Veteran twins. PTSD was measured by the Composite International Diagnostic Interview; health functioning and disability were assessed using the Veterans RAND 36-Item Health Survey (VR-36) and the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0). All data collection took place between 2010 and 2012.Results
Average age of the 5,574 participating Veterans (2,102 Vietnam theater and 3,472 non-theater) was 61.0 years. Veterans with PTSD had poorer health functioning across all domains of VR-36 and increased disability for all subscales of WHODAS 2.0 (all p < .001) compared with Veterans without PTSD. Veterans with PTSD were in poorer overall health on the VR-36 physical composite summary (PCS) (effect size = 0.31 in theater and 0.47 in non-theater Veterans; p < .001 for both) and mental composite summary (MCS) (effect size = 0.99 in theater and 0.78 in non-theater Veterans; p < .001 for both) and had increased disability on the WHODAS 2.0 summary score (effect size = 1.02 in theater and 0.96 in non-theater Veterans; p < .001 for both). Combat exposure, independent of PTSD status, was associated with lower PCS and MCS scores and increased disability (all p < .05, for trend). Within-pair analyses in twins discordant for PTSD produced consistent findings.Conclusions
Vietnam-era Veterans with PTSD have diminished functioning and increased disability. The poor functional status of aging combat-exposed Veterans is of particular concern. 相似文献999.
ABSTRACTAlthough dissociation is believed to develop in early childhood, there is little research prospectively examining childhood dissociation or parental contributions related to its development. The current study sought to examine parent factors prospectively related to changes in dissociation symptoms in childhood. The current study sampled 68 mother-child dyads at two time points, when children were 3–4 and then 5–6 years, in which mothers with emotion dysregulation were oversampled. Maternal emotion dysregulation was assessed at both time points. Maternal dissociation was assessed only at time two. Child dissociation was assessed at each time point using a modified subscale of the Child Behavioral Checklist. Results showed moderate stability in childhood dissociation across time points. Further, maternal emotion dysregulation and dissociation were both significantly correlated with children’s dissociation. Accounting for several covariates, time one maternal emotion dysregulation was prospectively associated with preschoolers’ dissociative behaviors at 5–6 years old. The present work suggests that symptoms of dissociation can be observed early in childhood and that maternal factors play an early role in the development of dissociation in children. 相似文献
1000.
Michael D. Perry P. Lewis White Michael Ruddy 《Journal of clinical microbiology》2014,52(5):1708-1710
Requests for direct molecular diagnosis of mycobacterial disease are increasingly warranted. The Anyplex MTB/NTM assay demonstrates sensitivities, specificities, and positive and negative predictive values of 1.00, 0.96, 0.93, and 1.00 for Mycobacterium tuberculosis complex (MTBC) and 1.00, 0.97, 0.75, and 1.00 for nontuberculous mycobacteria (NTM) detection, respectively, making it a suitable screening test for mycobacterial detection. 相似文献