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1.
Orthod Craniofac Res ; 27(1): 110-117, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-37501526

RESUMEN

BACKGROUND: A longitudinal cohort study was established to investigate the well-being of children born with cleft lip and/or palate (CL/P) during the COVID-19 pandemic, in Victoria, Australia. MATERIALS AND METHODS: The Royal Children's Hospital cleft service database was used to identify children aged between 4 and 17 years old born with an isolated CL/P. Families of eligible children who consented to participate were asked to complete the Strengths and Difficulties Questionnaire (SDQ) between October and December 2020 and again 6-month later. SDQ results from typically developing Australian children during the COVID-19 pandemic were utilized from a previously published study. RESULTS: 63 parents completed the baseline questionnaire, with 44 completing the 6-month follow-up. For participants at baseline, the mean age was 8.9 years, with 55% male. All outcome domains of the SDQ improved between baseline and timepoint 2, with the difference in total difficulties scores being statistically significant, indicating a reduction in total difficulties at timepoint 2, associated with the easing of COVID-19 restrictions. When compared with the Australian population during the COVID-19 pandemic, Victorian children born with CL/P had lower SDQ scores for all difficulties outcome domains, with statistically significant results for conduct problems, hyperactivity, peer problems and total difficulties, indicating fewer difficulties for children born with CL/P. CONCLUSIONS: Children born with CL/P experienced fewer difficulties when compared with the typically developing Australian population during the COVID-19 pandemic. The level of restrictions imposed because of the pandemic also had little influence on the well-being of these children.


Asunto(s)
COVID-19 , Labio Leporino , Fisura del Paladar , Niño , Humanos , Masculino , Preescolar , Adolescente , Femenino , Labio Leporino/epidemiología , Fisura del Paladar/epidemiología , Estudios Longitudinales , Pandemias , Australia/epidemiología , COVID-19/epidemiología
2.
J Public Health Dent ; 83(4): 397-407, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-38018025

RESUMEN

BACKGROUND: The aim of this study was to investigate factors associated with burnout in Australian dental practitioners. METHODS: A cross-sectional survey of 1483 Australian dental practitioners was conducted from Oct to Dec 2021. Participants reported burnout using the Sydney Burnout Measure, and aspects of mental health including psychological distress, depression, and anxiety disorders. Predictors of burnout were explored using a generalized linear model with a stepped approach including demographic, health and risk factor variables. RESULTS: One in four participants were classified as likely to be experiencing burnout. Burnout was associated with working in a regional/rural location (ß = 2.82, p < 0.001), an academic/non-clinical role (ß = 5.01, p = 0.037), more years of experience as a dental practitioner (ß = 0.08, p = 0.022), a current diagnosis of depression (ß = 2.38, p = 0.049), moderate/severe psychological distress (ß = 7.16, p < 0.001), poor self-rated physical health (ß = 5.84, p < 0.001) and increasing alcohol consumption (ß = 0.17, p = 0.020). Participants who scored high on resilience (ß = -0.23, p = 0.002) or perfectionism (ß = -0.24, p < 0.001) had lower burnout scores. CONCLUSION: Australian dental practitioners appear to be at high risk of burnout which may impact on their health and wellbeing and ability to deliver patient care. There is a need for support services to manage burnout and education to address workplace and environmental factors that may contribute to burnout.


Asunto(s)
Agotamiento Profesional , Odontólogos , Humanos , Estudios Transversales , Australia , Rol Profesional , Agotamiento Profesional/etiología , Agotamiento Profesional/psicología , Encuestas y Cuestionarios
3.
Aust Dent J ; 68(3): 160-170, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37199455

RESUMEN

BACKGROUND: Dental practitioners are known to experience a high level of stress, but little is known about the mental health of Australian dental practitioners. The aim of this study was to investigate the prevalence of mental health conditions among Australian dental practitioners. METHODS: A cross sectional survey of 1483 Australian dental practitioners was carried out from October to December 2021. Participants reported aspects of mental health including depression, anxiety disorder, burnout (Sydney Burnout Measure) and psychological distress (Kessler Psychological Distress Scale and General Health Questionnaire 12). RESULTS: Self-reported psychological distress was high, with 32.0% rated as having moderate or severe psychological distress and 59.4% a high likelihood of minor (or more severe) psychological distress. One in four participants (24.8%) were classified as likely to be experiencing burnout, with 25.9% reporting ever having a diagnosis of depression, 11.4% a current diagnosis of depression, 23.1% ever having a diagnosis of anxiety disorder and 12.9% a current diagnosis of anxiety disorder. CONCLUSION: Australian dental practitioners reported a high burden of psychological distress, burnout and mental health issues, suggesting a need for education and programmes to support their mental health and wellbeing. © 2023 Australian Dental Association.


Asunto(s)
Agotamiento Profesional , Salud Mental , Humanos , Estudios Transversales , Odontólogos , Australia/epidemiología , Rol Profesional , Agotamiento Profesional/epidemiología , Agotamiento Profesional/psicología , Depresión/epidemiología , Encuestas y Cuestionarios , Estrés Psicológico/epidemiología , Estrés Psicológico/psicología
5.
J Nutr Health Aging ; 26(11): 1025-1032, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36437771

RESUMEN

OBJECTIVES: Protein is a key macronutrient for preserving physical function, but the role of protein intake on functional status may differ in men and women. We sought to examine the associations of daily protein intake and distribution on functional limitations in older American men and women. DESIGN: Cross-sectional. SETTING: Population-based survey. PARTICIPANTS: The analytic sample included 3,976 men and 4,081 women aged ≥60-years from the 2007-2016 waves of the National Health and Nutrition Examination Survey. MEASUREMENTS: Participants reported their ability to perform basic activities of daily living, instrumental activities of daily living, leisure and social activities, lower extremity mobility activities, and general physical tasks. Those reporting difficulty or an inability in completing such functional tasks were considered as having a functional limitation. Protein intake was determined with dietary recalls and participants revealed functional limitations. Protein recommendations of ≥0.80, ≥1.00, and ≥1.50 g/kg/day were used. Based on these cut-points, we also investigated distribution of protein across 4 eating occasions at ≥0.20, ≥0.25, and ≥0.38 g/kg/meal, respectively. RESULTS: Older women meeting each recommendation had decreased odds for functional limitations: 0.55 (95% confidence interval (CI): 0.40-0.75) for ≥0.80 g/kg/day, 0.75 (CI: 0.58-0.97) for ≥1.00 g/kg/day, and 0.72 (CI: 0.55-0.94) for ≥1.5 g/kg/day. No significant associations were observed in older men. Further, older women with protein consumption ≥0.20 g/kg/meal had decreased odds for functional limitations: 0.24 (CI: 0.10-0.61) for 1 occasion, 0.20 (CI: 0.08-0.49) for 2 occasions, 0.16 (CI: 0.07-0.40) for 3 occasions, and 0.12 (CI: 0.04-0.32) for 4 occasions. A similar trend was observed for intake ≥0.25 g/kg/meal: 0.31 (CI: 0.16-0.62) for 2 occasions, 0.30 (CI: 0.14-0.61) for 3 occasions, and 0.31 (CI: 0.12-0.78) for 4 occasions. Women with 1 and 2 eating occasions at ≥0.38 g/kg/meal of protein had 0.66 (CI: 0.48-0.91) and 0.54 (CI: 0.37-0.79) decreased odds for functional limitations, respectively. CONCLUSION: Trials that are powered to detect the effects of protein on functional status in women will help to establish causality.


Asunto(s)
Actividades Cotidianas , Dieta , Masculino , Humanos , Estados Unidos , Femenino , Anciano , Encuestas Nutricionales , Estudios Transversales , Comidas
7.
J Frailty Aging ; 11(2): 143-150, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35441190

RESUMEN

Handgrip dynamometers are widely used to measure handgrip strength (HGS). HGS is a safe and easy to obtain measure of strength capacity, and a reliable assessment of muscle function. Although HGS provides robust prognostic value and utility, several protocol variants exist for HGS in clinical settings and translational research. This lack of methodological consistency could threaten the precision of HGS measurements and limit comparisons between the growing number of studies measuring HGS. Providing awareness of the protocol variants for HGS and making suggestions to reduce the implications of these variants will help to improve methodological consistency. Moreover, leveraging recent advancements in HGS equipment may enable us to use more sophisticated HGS dynamometer technologies to better assess muscle function. This Special Article will 1) highlight differences in HGS protocols and instrumentation, 2) provide recommendations to better specify HGS procedures and equipment, and 3) present future research directions for studies that measure HGS. We also provided a minimum reporting criteria framework to help future research studies avoid underreporting of HGS procedures.


Asunto(s)
Fuerza de la Mano , Tecnología , Fuerza de la Mano/fisiología , Humanos , Pronóstico , Ciencia Traslacional Biomédica
9.
Age Ageing ; 49(4): 634-639, 2020 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-32037458

RESUMEN

OBJECTIVE: to estimate temporal trends in handgrip strength (HGS) for older Japanese adults between 1998 and 2017. DESIGN AND METHODS: adults aged 60-79 years were included. Annual nationally representative HGS data (n = 176,449) for the 19-year study period were obtained from the Japanese Ministry of Education, Culture, Sports, Science and Technology. Temporal trends in mean HGS were estimated by sample-weighted regression models relating the year of testing to mean HGS. National trends in absolute, percent and standardised HGS were estimated by a post-stratified population-weighting procedure. Temporal trends in variability were estimated as the ratio of coefficients of variation (CVs). RESULTS: collectively, there was a small improvement in mean HGS of 1.4 kg (95% confidence interval [CI]: 1.3-1.5), 4.5% (95%CI: 4.3-4.7) or 0.27 standard deviations (95%CI: 0.26-0.28) between 1998 and 2017. The rate of improvement progressively increased over time, with more recent values (post-2008) 1.5-fold larger than earlier values. Gender- and age-related temporal differences were negligible. Variability in HGS declined substantially over time (ratio of CVs [95%CI]: 0.88 [0.86-0.90]), with declines 1.9-fold larger in women compared to men and 1.7-fold larger in 70- to 79-year-olds compared to 60- to 69-year-olds. CONCLUSIONS: there has been a small, progressive improvement in mean HGS for older Japanese adults since 1998, which is suggestive of a corresponding improvement in strength capacity. The substantial decline in variability indicates that the improvement in mean HGS was not uniform across the population.


Asunto(s)
Fuerza de la Mano , Anciano , Escolaridad , Femenino , Humanos , Japón/epidemiología , Masculino
10.
J Nutr Health Aging ; 24(1): 16-19, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-31886803

RESUMEN

OBJECTIVE: Handgrip strength is considered a biomarker of nutritional status and strength capacity, which are both linked to heart complications. However, it is not well understood how weakness, as measured by handgrip strength, factors into common heart conditions seen in aging adults such as chronic heart failure (CHF). The purpose of this study was to determine the association between weakness and incident CHF for aging Americans. DESIGN: Longitudinal-Panel. SETTING: Physical measures were completed during enhanced face-to-face interviews. The core interview was typically conducted over the telephone. PARTICIPANTS: Data from 17,431 adults aged at least 50 years who identified as Black or White, completed interviews without a proxy, and participated in at least one wave of the 2006-2014 waves of the Health and Retirement Study were included. MEASUREMENTS: Handgrip strength was measured with a hand-held dynamometer. Healthcare provider diagnosed CHF was self-reported at each wave. Sex- and race-specific maximal handgrip strength cut-points were used for determining weakness (Black men: <40-kilograms, Black women: <31-kilograms, White men: <35-kilograms, White women: <22-kilograms). A covariate-adjusted Cox model analyzed the association between weakness and incident CHF. RESULTS: Of those included, 5,397 (31.0%) were weak and 327 (1.9%) developed CHF during the mean follow-up of 4.7±2.7 years. Those who were weak had a 35% higher risk (hazard ratio: 1.35; 95% confidence interval: 1.05, 1.74) of developing CHF, compared to those who were not-weak. CONCLUSION: Measures of handgrip strength should be utilized by healthcare providers for assessing age-related weakness, nutritional status, and CHF risk. Likewise, interventions aiming to prevent or treat CHF in aging adults should incorporate measures of handgrip strength for helping to determine efficacy of intervention programs.


Asunto(s)
Envejecimiento/fisiología , Fuerza de la Mano/fisiología , Insuficiencia Cardíaca/fisiopatología , Debilidad Muscular/fisiopatología , Estado Nutricional/fisiología , Negro o Afroamericano , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Jubilación , Autoinforme , Encuestas y Cuestionarios
12.
J Frailty Aging ; 8(3): 141-145, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31237315

RESUMEN

OBJECTIVES: The primary purpose of this study was to determine the time-varying associations between decreased handgrip strength (HGS) and individual instrumental activities of daily living (IADL) impairments for a nationally-representative sample of aging adults in the United States. DESIGN: Longitudinal-Panel. SETTING: Detailed interviews were completed in person and core interviews were typically completed over the telephone. PARTICIPANTS: A total of 15,336 participants aged at least 50 years who participated in the 2006 wave of the Health and Retirement Study were followed biennially for 8-years. MEASUREMENTS: A hand-held dynamometer assessed HGS and performance in IADLs were self-reported. RESULTS: Every 5-kilogram decrease in HGS was associated with an increased odds ratio for the following IADL impairments: 1.11 (95% confidence interval (CI): 1.09, 1.13) for using a map, 1.10 (CI: 1.07, 1.12) for grocery shopping, 1.09 (CI: 1.05, 1.14) for taking medications, 1.07 (CI: 1.05, 1.09) for preparing hot meals, 1.06 (CI: 1.04, 1.08) for managing money, and 1.05 (CI: 1.02, 1.09) for using a telephone. CONCLUSIONS: Decreased HGS was associated with each IADL impairment, and slightly different associations were observed in individual IADL tasks for aging adults in the United States. Our findings suggest that decreased HGS, which is reflective of reduced function of the neuromuscular system, is associated with diminished performance in autonomous living tasks during aging. Losses in HGS may lead to the development of an IADL impairment. Therefore, health-care providers working with aging adults should utilize measures of HGS as a screening tool for identifying future deficits in neuromuscular functioning. Interventions designed to preserve IADLs in aging adults should also include measures of HGS for detecting early changes in IADL capacity, and intervening at the onset of HGS declines may help aging adults retain their ability to live autonomously.


Asunto(s)
Actividades Cotidianas , Fuerza de la Mano/fisiología , Rendimiento Físico Funcional , Anciano , Humanos , Persona de Mediana Edad , Autoinforme , Estados Unidos
13.
J Nutr Health Aging ; 23(2): 172-174, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-30697627

RESUMEN

OBJECTIVES: Understanding the role of functional capacity on longevity is important as the population in the United States ages. The purpose of this study was to determine the burden of instrumental activities of daily living (IADL) and activities of daily living (ADL) disabilities for a nationally-representative sample of middle-aged and older adults in the United States. DESIGN: Longitudinal-Panel. SETTING: Core interviews were often performed in person or over the telephone. PARTICIPANTS: A sub-sample of 31,055 participants aged at least 50 years from the 1998-2014 waves of the Health and Retirement Study who reported having a functional disability were included. MEASUREMENTS: Ability to perform IADLs and ADLs were self-reported at each wave. The National Death Index was used to ascertain date of death. The number of years of life that were lost (YLLs) and years lived with a disability (YLDs) were summed for the calculation of disability-adjusted life years (DALYs). Sampling weights were used in the analyses to make the DALYs nationally-representative. The results for YLLs, YLDs, and DALYs are reported in thousands. RESULTS: Of the participants included, 14,990 had an IADL disability and 13,136 had an ADL disability. Men and women with an IADL disability had 236,037 and 233,772 DALYs, respectively; whereas, there were 178,594 DALYs for males and 253,630 DALYs for females with an ADL disability. Collectively, there were 469,809 years of healthy life lost from IADL impairments, and 432,224 years of healthy life lost from ADL limitations. CONCLUSIONS: These findings should be used to inform healthcare providers and guide interventions aiming to preserve the functional capacity of aging adults. Prioritizing health-related resources for mitigating the burden of functional disabilities may help aging adults increase their quality of life and life expectancy over time.


Asunto(s)
Actividades Cotidianas , Personas con Discapacidad/estadística & datos numéricos , Estado de Salud , Longevidad/fisiología , Anciano , Anciano de 80 o más Años , Envejecimiento , Personas con Discapacidad/rehabilitación , Femenino , Recursos en Salud , Humanos , Esperanza de Vida , Masculino , Persona de Mediana Edad , Calidad de Vida/psicología , Años de Vida Ajustados por Calidad de Vida , Jubilación , Autoinforme , Encuestas y Cuestionarios , Estados Unidos
15.
J Neurol Sci ; 375: 404-410, 2017 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-28320178

RESUMEN

INTRODUCTION: Von Willebrand factor propeptide (VWF:Ag II) is proposed to be a more sensitive marker of acute endothelial activation than von Willebrand factor antigen (VWF:Ag). Simultaneous data on VWF:Ag and VWF:Ag II profiles are very limited following TIA and ischaemic stroke. METHODS: In this prospective, observational, case-control study, plasma VWF:Ag and VWF:Ag II levels were quantified in 164 patients≤4weeks of TIA or ischaemic stroke (baseline), and then ≥14days (14d) and ≥90days (90d) later, and compared with those from 27 healthy controls. TIA and stroke subtyping was performed according to the TOAST classification. The relationship between VWF:Ag and VWF:Ag II levels and platelet activation status was assessed. RESULTS: 'Unadjusted' VWF:Ag and VWF:Ag II levels were higher in patients at baseline, 14d and 90d than in controls (p≤0.03). VWF:Ag levels remained higher in patients than controls at baseline (p≤0.03), but not at 14d or 90d after controlling for differences in age or hypertension, and were higher in patients at baseline and 90d after controlling for smoking status (p≤0.04). 'Adjusted' VWF:Ag II levels were not higher in patients than controls after controlling for age, hypertension or smoking (p≥0.1). Patients with symptomatic carotid stenosis (N=46) had higher VWF:Ag and VWF:Ag II levels than controls at all time-points (p≤0.002). There was no significant correlation between platelet activation status and VWF:Ag or VWF:Ag II levels. CONCLUSIONS: VWF:Ag and VWF:Ag II levels are increased in an overall TIA and ischaemic stroke population, especially in patients with recently symptomatic carotid stenosis. VWF:Ag II was not superior to VWF:Ag at detecting acute endothelial activation in this cohort and might reflect timing of blood sampling in our study.


Asunto(s)
Ataque Isquémico Transitorio/sangre , Precursores de Proteínas/sangre , Accidente Cerebrovascular/sangre , Factor de von Willebrand/metabolismo , Anciano , Antígenos CD/sangre , Biomarcadores/sangre , Isquemia Encefálica/complicaciones , Estudios de Casos y Controles , Femenino , Citometría de Flujo , Humanos , Ataque Isquémico Transitorio/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Inhibidores de Agregación Plaquetaria , Estudios Prospectivos , Accidente Cerebrovascular/tratamiento farmacológico , Accidente Cerebrovascular/etiología
16.
J Perinatol ; 37(4): 360-368, 2017 04.
Artículo en Inglés | MEDLINE | ID: mdl-28079866

RESUMEN

OBJECTIVE: Gestational diabetes mellitus (GDM) in singleton pregnancy is associated with large for gestational age neonates and adverse perinatal outcomes; however, the impact of GDM in twin pregnancy is unclear. Thus, the aim of this study is to assess the perinatal outcomes of twin pregnancies complicated by GDM by performing a meta-analysis of observational studies. STUDY DESIGN: Studies investigating GDM in twin pregnancy were identified through an online search of three databases: Medline, Embase and Web of Science. Selection criteria comprised full paper observational studies (retrospective or prospective) published in English that examined GDM in twin pregnancy compared with non-GDM twin pregnancy and reported on birth weight and/or adverse perinatal outcomes. Random-effects models with inverse-variance weighting were used to calculate standardized mean differences and unadjusted odds ratios. Sensitivity analyses were carried out to determine the impact of possible maternal confounders (body mass index and age) and GDM diagnostic criteria on perinatal outcomes. RESULTS: Thirteen observational studies were included. GDM twins were born at the same gestation as non-GDM twins, with marginally lower birth weight. There was no difference in the incidence of large or small for gestational age neonates. Although there was no correlation between GDM in twin pregnancy and respiratory distress, neonatal hypoglycemic or low Apgar score, GDM twins had a higher rate of neonatal intensive care unit admission (OR 1.49; 95% confidence interval: 1.10, 2.02; P<0.01). CONCLUSION: Identification and subsequent treatment of GDM in twin pregnancy demonstrates a similar risk of adverse perinatal outcomes compared with non-GDM twin pregnancies.


Asunto(s)
Diabetes Gestacional/epidemiología , Resultado del Embarazo/epidemiología , Embarazo Gemelar , Adulto , Peso al Nacer , Femenino , Edad Gestacional , Humanos , Incidencia , Recién Nacido , Estudios Observacionales como Asunto , Oportunidad Relativa , Embarazo
17.
J Chem Phys ; 145(15): 154707, 2016 Oct 21.
Artículo en Inglés | MEDLINE | ID: mdl-27782456

RESUMEN

Surface ordering of pentacene molecules adsorbed on an aperiodic Cu surface has been studied with density functional theory (DFT) and scanning tunnelling microscopy as a function of coverage. Below 0.73 ML (5.3 × 1013 molecules cm-2), the adsorbate structure is row-like with the molecular axes aligned with the rows in the Cu structure. Between this coverage and 1 ML (7.3 × 1013 molecules cm-2), a structural phase with a checkerboard structure is seen. At this coverage region, the molecules are very close to each other which leads to unusual bending. At higher coverages, a further phase transition to a high-density row structure is seen for most of the film. DFT with van der Waals functionals is employed to study how the molecule-molecule and molecule-surface interactions evolve as a function of coverage.

18.
J Sports Sci ; 34(11): 1094-8, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26367197

RESUMEN

Running economy is a reflection of the amount of inspired oxygen required to maintain a given velocity and is considered a determining factor for running performance. Athletic footwear has been advocated as a mechanism by which running economy can be enhanced. New commercially available footwear has been developed in order to increase energy return, although their efficacy has not been investigated. This study aimed to examine the effects of energy return footwear on running economy in relation to conventional running shoes. Twelve male runners completed 6-min steady-state runs in conventional and energy return footwear. Overall, oxygen consumption (VO2), heart rate, respiratory exchange ratio, shoe comfort and rating of perceived exertion were assessed. Moreover, participants subjectively indicated which shoe condition they preferred for running. Differences in shoe comfort and physiological parameters were examined using Wilcoxon signed-rank tests, whilst shoe preferences were tested using a chi-square analysis. The results showed that VO2 and respiratory exchange ratio were significantly lower, and shoe comfort was significantly greater, in the energy return footwear. Given the relationship between running economy and running performance, these observations indicate that the energy return footwear may be associated with enhanced running performance in comparison to conventional shoes.


Asunto(s)
Rendimiento Atlético/fisiología , Consumo de Oxígeno , Carrera/fisiología , Zapatos , Fenómenos Biomecánicos , Frecuencia Cardíaca , Humanos , Masculino , Adulto Joven
20.
J Chem Phys ; 142(9): 094703, 2015 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-25747095

RESUMEN

The use of quasicrystals as precursors to catalysts for the steam reforming of methanol is potentially one of the most important applications of these new materials. To develop application as a technology requires a detailed understanding of the microscopic behavior of the catalyst. Here, we report the effect of leaching treatments on the surface microstructure, chemical composition, and valence band of the icosahedral (i-) Al-Cu-Fe quasicrystal in an attempt to prepare a model catalyst. The high symmetry fivefold surface of a single grain i-Al-Cu-Fe quasicrystal was leached with NaOH solution for varying times, and the resulting surface was characterized by x-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The leaching treatments preferentially remove Al producing a capping layer consisting of Fe and Cu oxides. The subsurface layer contains elemental Fe and Cu in addition to the oxides. The quasicrystalline bulk structure beneath remains unchanged. The subsurface gradually becomes Fe3O4 rich with increasing leaching time. The surface after leaching exhibits micron sized dodecahedral cavities due to preferential leaching along the fivefold axis. Nanoparticles of the transition metals and their oxides are precipitated on the surface after leaching. The size of the nanoparticles is estimated by high resolution transmission microscopy to be 5-20 nm, which is in agreement with the AFM results. Selected area electron diffraction (SAED) confirms the crystalline nature of the nanoparticles. SAED further reveals the formation of an interface between the high atomic density lattice planes of nanoparticles and the quasicrystal. These results provide an important insight into the preparation of model catalysts of nanoparticles for steam reforming of methanol.

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