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排序方式: 共有1263条查询结果,搜索用时 15 毫秒
41.
Matthew D Walker Katherine Dinelle Rick Kornelsen Siobhan McCormick Chenoa Mah James E Holden Matthew J Farrer A Jon Stoessl Vesna Sossi 《Journal of cerebral blood flow and metabolism》2013,33(1):59-66
Longitudinal measurements of dopamine (DA) uptake and turnover in transgenic rodents may be critical when developing disease-modifying therapies for Parkinson''s disease (PD). We demonstrate methodology for such measurements using [18F]fluoro-3,4-dihydroxyphenyl-L-alanine ([18F]FDOPA) positron emission tomography (PET). The method was applied to 6-hydroxydopamine lesioned rats, providing the first PET-derived estimates of DA turnover for this species. Control (n=4) and unilaterally lesioned (n=11) rats were imaged multiple times. Kinetic modeling was performed using extended Patlak, incorporating a kloss term for metabolite washout, and modified Logan methods. Dopaminergic terminal loss was measured via [11C]-(+)-dihydrotetrabenazine (DTBZ) PET. Clear striatal [18F]FDOPA uptake was observed. In the lesioned striatum the effective DA turnover increased, shown by a reduced effective distribution volume ratio (EDVR) for [18F]FDOPA. Effective distribution volume ratio correlated (r>0.9) with the [11C]DTBZ binding potential (BPND). The uptake and trapping rate (kref) decreased after lesioning, but relatively less so than [11C]DTBZ BPND. For normal controls, striatal estimates were kref=0.037±0.005 per minute, EDVR=1.07±0.22 and kloss=0.024±0.003 per minute (30 minutes turnover half-time), with repeatability (coefficient of variation) ≤11%. [18F]fluoro-3,4-dihydroxyphenyl-L-alanine PET enables measurements of DA turnover in the rat, which is useful for developing novel therapies for PD. 相似文献
42.
Wei-Long Xu Siobhan J. Bradley Yang Xu Fei Zheng Christopher R. Hall Kenneth P. Ghiggino Trevor A. Smith 《RSC advances》2020,10(71):43579
Zero-dimensional (0D) quantum confinement can be achieved in perovskite materials by the confinement of electron and hole states to single PbX64− perovskite octahedra. In this work, 0D perovskite (Cs4PbBr6) micro-crystals were prepared by a simple thermally-assisted solution method and thoroughly characterized. The micro-crystals show a high level of crystallinity and a high photoluminescence quantum yield of 45%. The radiative recombination coefficient of the 0D perovskite micro-crystals, 1.5 × 10−8 s−1 cm3, is two orders of magnitude higher than that of typical three-dimensional perovskite and is likely a strong contributing factor to the high emission efficiency of 0D perovskite materials. Temperature dependent luminescence measurements provide insight into the role of thermally-activated trap states. Spatially resolved measurements on single 0D perovskite micro-crystals reveal uniform photoluminescence intensity and emission decay behaviour suggesting the solution-based fabrication method yields a high-quality and homogenous single-crystal material. Such uniform emission reflects the intrinsic 0D nature of the material, which may be beneficial to device applications.0D Cs4PbBr6 perovskite microcrystals exhibit a radiative recombination coefficient two orders of magnitude higher than typical 3D perovskite. 相似文献
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44.
Janet McNally Siobhan Hugh‐Jones Samantha Caton Carel Vereijken Hugo Weenen Marion Hetherington 《Maternal & child nutrition》2016,12(2):205-228
Responsive feeding has been identified as important in preventing overconsumption by infants. However, this is predicated on an assumption that parents recognise and respond to infant feeding cues. Despite this, relatively little is understood about how infants engage parental feeding responses. Therefore, the aim of this systematic review was to identify what is known about infant communication of hunger and satiation and what issues impact on the expression and perception of these states. A search of Medline, CINAHL, Web of Science, PsycINFO, Science Direct and Maternal and Infant care produced 27 papers. Eligibility criteria included peer reviewed qualitative and/or quantitative publications on feeding behaviours, hunger, and satiation/satiety cues of typically developing children in the first 2 years of life. Papers published between 1966 and 2013 were included in the review. The review revealed that feeding cues and behaviours are shaped by numerous issues, such as infants' physical attributes, individual psychological factors and environmental factors. Meanwhile, infant characteristics, external cues and mothers' own characteristics affect how feeding cues are perceived. The existing literature provides insights into many aspects of hunger and satiation in infancy; however, there are significant gaps in our knowledge. There is a lack of validated tools for measuring hunger and satiation, a need to understand how different infant characteristics impact on feeding behaviour and a need to extricate the respective contributions of infant and maternal characteristics to perceptions of hunger and satiation. Further research is also recommended to differentiate between feeding driven by liking and that driven by hunger. 相似文献
45.
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47.
Corvin A Donohoe G McGhee K Murphy K Kenny N Schwaiger S Nangle JM Morris D Gill M 《Neuroscience letters》2007,426(2):97-100
A series of genetic studies have identified the D-amino acid oxidase (DAO) gene as potentially contributing to schizophrenia susceptibility. An interacting gene, D-amino acid oxidase activator (DAOA) has also been implicated and it has been suggested that variation at these genes may influence the efficiency of glutamate gating at N-methyl-D-aspartate-type (NMDA) receptors. However, recent data suggests that DAOA may influence susceptibility to mood episodes across the spectrum of psychotic disorders rather than contributing to a specific psychosis phenotype. The aim of this study was to determine whether risk variation at DAO is similarly associated with affective or other clinical symptoms in psychosis. We have previously reported association between risk variation at DAO and schizophrenia in an Irish case-control sample. In this study we investigated the relationship between a defined genetic risk variant at DAO and PANSS-derived clinical symptom factors in a sample of 249 patients using principal component and Kruskal-Wallis analyses. Carriers of the DAO risk variant scored significantly higher on the 'depression/anxiety' factor than non-carriers (H=9.02, d.f.=2, p=0.01). These data suggest a potential role for DAO in susceptibility to depressive symptoms in schizophrenia, but a more general role for DAO in affective disorders cannot be excluded. 相似文献
48.
Geeske Peeters Siobhan Leahy Sean Kennelly Rose Anne Kenny 《Journal of the American Medical Directors Association》2018,19(3):248-254.e3
Background
Fear of falling (FoF) is present in 20% to 85% of older adults and may be an early marker of decline in global cognitive functioning (GCF). We tested the hypothesis that FoF is associated with lower levels of GCF (cross-sectional) and greater decline in GCF (prospective) in adults aged 50 and older.Design
Observational cohort study.Setting
The Irish Longitudinal Study on Ageing, a population-based study.Participants
Data were from 4931 participants (mean age 62.9 ± 9.1, range 50–98, 54.3% female).Measurements
FoF was based on self-report in 2010. GCF was measured with the Montreal Cognitive Assessment (MoCA) and Mini Mental Status Examination (MMSE) in 2010 and 2014. The cross-sectional association was examined using linear regression unadjusted and after adjustment for demographic and health factors. The prospective association between FoF and the odds of >1-SD decline in GCF were examined using logistic regression. Interaction with age and mediation by social and physical activities were examined.Results
In 2010, 21.9% of participants reported FoF. In the unadjusted cross-sectional models, those with FoF had lower scores on the MoCA (B ?1.15, 95% confidence interval [CI] ?1.40 to ?0.90) and MMSE (B ?0.52, CI ?0.67 to ?0.37). In the unadjusted prospective models, FoF was associated with a greater odds of decline in MoCA (odds ratio [OR] 1.60, CI 1.26–2.04) and MMSE (OR 1.64, CI 1.29–2.08). After adjustment for covariates, all associations attenuated and were no longer statistically significant, except the association with decline in MoCA (OR 1.32, CI 1.01–1.71). No statistically significant interaction with age was found (P > .37). Additional adjustment for social and physical activity did not change the results.Conclusions
The findings provide weak evidence for FoF as a predictor of cognitive decline. 相似文献49.
Sonya S. Brady PhD Amanda Berry PhD CRNP Deepa R. Camenga MD MHS Colleen M. Fitzgerald MD MS Sheila Gahagan MD MPH Cecilia T. Hardacker MSN RN CNL Bernard L. Harlow PhD Jeni Hebert-Beirne PhD MPH D. Yvette LaCoursiere MD Jessica B. Lewis PhD MFT Lisa K. Low PhD CNM Jerry L. Lowder MD MSc Alayne D. Markland DO MSc Gerald McGwin PhD Diane K. Newman DNP ANP-BC FAAN Mary H. Palmer PhD David A. Shoham PhD Ariana L. Smith MD Ann Stapleton MD Beverly R. Williams PhD Siobhan Sutcliffe PhD Prevention of Lower Urinary Tract Symptoms 《Neurourology and urodynamics》2020,39(4):1185-1202
50.
Naman R. Rao BDS MMSc Nathaniel Treister DMD DMSc Andrea Axtell MD Jillian Muhlbauer DMD Puhan He DMD Agnes Lau DMD Ross Icyda DMD Elbert Heng MD Daniel Rinewalt MD Siobhan McGurk BS Kevin Kennedy MS Tsuyoshi Kaneko MD Duke Cameron MD Herve Sroussi DMD PhD 《Journal of cardiac surgery》2020,35(11):2995-3003