1,318 research outputs found

    SPIRIT Checklist, Myopia Outcome Study of Atropine in Children (MOSAIC): Design and Methodology

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    Purpose The Myopia Outcome Study of Atropine in Children (MOSAIC) aims to explore the efficacy, safety, acceptability and mechanisms of action of 0.01% atropine for myopia control in a European population. Methods MOSAIC is an investigator-led, double-masked, placebo-controlled, randomised clinical trial (RCT) investigating the efficacy, safety and mechanisms of action of 0.01% atropine in myopia progression management. During Phase 1 of the trial, 250 children aged 6-16 years with progressive myopia apply eye drops once nightly in both eyes from randomisation to month 24. No treatment is given during Phase 2 from month 24 to 36 (washout period) for those participants initially randomised to the intervention arm (n=167), during which any potential rebound effects on termination of treatment will be monitored. All participants initially assigned to the placebo (n=83) crossover to the intervention arm of the study for Phase 2, and from month 24 to 36, instil 0.01% atropine eye drops once nightly. Further treatment and monitoring beyond 36 months is planned (Phase 3) and will be designed dependent on the outcomes of Phase 1. Results The primary outcome measure is spherical equivalent refractive error progression at 24 months. Secondary outcome measures include axial length change as well as the rebound, safety and acceptability profile of 0.01% atropine. Additional analyses will include the mechanisms of action of 0.01% atropine for myopia control. Conclusion The generalisability of results from previous clinical trials investigating atropine for myopia control is limited by the ethnic make-up of the study populations, which were predominantly Asian. MOSAIC is the first RCT to explore the efficacy, safety and mechanisms of action of unpreserved 0.01% atropine in a predominantly white population

    Heterogeneous Epoxidation of n-octene, Cyclooctene and Styrene Using a Chitosan 4-Salicyledinepalladium (II) Catalyst under Aerobic Conditions

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    Chitosan (CS) has been condensed with 4-salicylidene to form a 2CS-Hdhba Schiff-base. The heterogeneous catalytic epoxidations of n-octene, cyclooctene and styrene have been achieved by employing a [Pd(dhba(H2O)Cl] complex as a catalyst in the presence of oxygen at atmospheric pressure at 358 K. The influence of reaction temperature, reaction time and amount of catalyst on the epoxidation processes has also been investigated. The catalyst is easily recovered from the epoxidation reaction mixtures even after 10 catalytic cycles

    Severe Lumbar Disability Is Associated With Decreased Psoas Cross-Sectional Area in Degenerative Spondylolisthesis

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    Study Design: Retrospective cohort. Objectives: Alterations in lumbar paraspinal muscle cross-sectional area (CSA) may correlate with lumbar pathology. The purpose of this study was to compare paraspinal CSA in patients with degenerative spondylolisthesis and severe lumbar disability to those with mild or moderate lumbar disability, as determined by the Oswestry Disability Index (ODI). Methods: We retrospectively reviewed the medical records of 101 patients undergoing lumbar fusion for degenerative spondylolisthesis. Patients were divided into ODI score ≀40 (mild/moderate disability, MMD) and ODI score \u3e40 (severe disability, SD) groups. The total CSA of the psoas and paraspinal muscles were measured on preoperative magnetic resonance imaging (MRI). Results: There were 37 patients in the SD group and 64 in the MMD group. Average age and body mass index were similar between groups. For the paraspinal muscles, we were unable to demonstrate any significant differences in total CSA between the groups. Psoas muscle CSA was significantly decreased in the SD group compared with the MMD group (1010.08 vs 1178.6 mm2, P =.041). Multivariate analysis found that psoas CSA in the upper quartile was significantly protective against severe disability (P =.013). Conclusions: We found that patients with severe lumbar disability had no significant differences in posterior lumbar paraspinal CSA when compared with those with mild/moderate disability. However, severely disabled patients had significantly decreased psoas CSA, and larger psoas CSA was strongly protective against severe disability, suggestive of a potential association with psoas atrophy and worsening severity of lumbar pathology. © The Author(s) 2018

    Parental Attitudes to Myopia: a Key Agent of Change for Myopia Control?

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    Purpose With the increasing prevalence in myopia there is growing interest in active myopia prevention. This study aims to increase our understanding of parental attitudes to myopia development and control, as a means to inform future health planning and policy. It evaluates, for the first time, the attitude of parents to myopia and its associated risks, as well as assessing the exposure of Irish children to environmental factors that may influence their risk profile for myopia development. Methods Parents of 8–13 year old children in eight participating schools completed a questionnaire designed to assess their knowledge of and attitudes towards myopia and its risk factors. A structured diary was also used to capture daily activities of children in relation to myopia risk factors. Results Of 329 parents, just 46% considered that myopia presented a health risk to their children, while an identical number (46%) regarded it as an optical inconvenience. Myopia was also, but less frequently, considered an expense (31% of parents), a cosmetic inconvenience (14% of parents) and, by some, as a sign of intelligence (4% of parents) 76% of parents recognised the potential of digital technology to impact the eye, particularly as a cause of eyestrain and need for spectacles. Only 14% of parents expressed concern should their child be diagnosed with myopia. Compared to non myopic parents, myopic parents viewed myopia as more of an optical inconvenience (p \u3c 0.001), an expense (p \u3c 0.005) and a cosmetic inconvenience (p \u3c 0.001). There was a trend for myopic parents to limit screen time use in their household more than non‐myopic parents (p = 0.05). Parents who considered myopia a health risk sought to limit screen time more than parents who did not regard myopia as a health risk to their child (p = 0.01). Children spent significantly longer performing indoor proximal tasks (255 min) compared to time spent outdoors (180 min; p \u3c 0.0001) daily. Older (p = 0.001), urban (p = 0.0005) myopic (=0.04) children spent significantly more time at digital screens compared to younger non‐myopic children from a rural background. Conclusion Parental attitudes to myopia were typically nonchalant in relation to health risk. This is of particular concern given the impact parents have on children\u27s behaviour and choices with respect to such risk factors, demonstrating an acute need for societal sensitisation to the public health importance of myopia

    The test case of HD26965: difficulties disentangling weak Doppler signals from stellar activity

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    We report the discovery of a radial velocity signal that can be interpreted as a planetary-mass candidate orbiting the K dwarf HD26965, with an orbital period of 42.364±\pm0.015 days, or alternatively, as the presence of residual, uncorrected rotational activity in the data. Observations include data from HIRES, PFS, CHIRON, and HARPS, where 1,111 measurements were made over 16 years. Our best solution for HD26965 bb is consistent with a super-Earth that has a minimum mass of 6.92±\pm0.79 M⊕_{\oplus} orbiting at a distance of 0.215±\pm0.008 AU from its host star. We have analyzed the correlation between spectral activity indicators and the radial velocities from each instrument, showing moderate correlations that we include in our model. From this analysis, we recover a ∌\sim38 day signal, which matches some literature values of the stellar rotation period. However, from independent Mt. Wilson HK data for this star, we find evidence for a significant 42 day signal after subtraction of longer period magnetic cycles, casting doubt on the planetary hypothesis for this period. Although our statistical model strongly suggests that the 42-day signal is Doppler in origin, we conclude that the residual effects of stellar rotation are difficult to fully model and remove from this dataset, highlighting the difficulties to disentangle small planetary signals and photospheric noise, particularly when the orbital periods are close to the rotation period of the star. This study serves as an excellent test case for future works that aim to detect small planets orbiting `Sun-like' stars using radial velocity measurements.Comment: 16 pages, 10 figures, 13 tables, accepted for publication in A

    Quantifying the Detrimental Impacts of Land-Use and Management Change on European Forest Bird Populations

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    The ecological impacts of changing forest management practices in Europe are poorly understood despite European forests being highly managed. Furthermore, the effects of potential drivers of forest biodiversity decline are rarely considered in concert, thus limiting effective conservation or sustainable forest management. We present a trait-based framework that we use to assess the detrimental impact of multiple land-use and management changes in forests on bird populations across Europe. Major changes to forest habitats occurring in recent decades, and their impact on resource availability for birds were identified. Risk associated with these changes for 52 species of forest birds, defined as the proportion of each species' key resources detrimentally affected through changes in abundance and/or availability, was quantified and compared to their pan-European population growth rates between 1980 and 2009. Relationships between risk and population growth were found to be significantly negative, indicating that resource loss in European forests is an important driver of decline for both resident and migrant birds. Our results demonstrate that coarse quantification of resource use and ecological change can be valuable in understanding causes of biodiversity decline, and thus in informing conservation strategy and policy. Such an approach has good potential to be extended for predictive use in assessing the impact of possible future changes to forest management and to develop more precise indicators of forest health

    Recent developments and perspectives in CdS-based photocatalysts for water splitting

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    Over the past few years, many approaches have been developed progressively to produce hydrogen (H2) from water under solar light irradiation. This process of fuel production is clean, potentially cost-effective, and environment-friendly. At present, however, current technologies are unable to meet the industrial requirements because of high cost, low photoresponse, and insufficient catalytic performance. Among water splitting photocatalysts, CdS is considered to be an interesting and important material owing to its low cost, prominent catalytic activity, high absorption in the visible spectrum, and the suitable positions of its conduction (CB) and valence (VB) bands. There are, however, some associated problems such as the rapid recombination of photogenerated electron–hole pairs and photocorrosion that have severely hampered its practical usage. The efficient conversion of water to H2 depends on the extent to which the charge carriers, especially the electrons, are first generated and then have sufficient life-time for their effective utilization. This review highlights work over the past several years to improve the photocatalytic efficiency and stability of CdS for H2 production from water
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