7,218 research outputs found
Retinal development and ommin pigment in the cranchiid squid Teuthowenia pellucida (Cephalopoda: Oegopsida)
The cranchiid Teuthowenia pellucida, like many deep-sea squid species, possesses large
eyes that maximise light sensitivity in a nearly aphotic environment. To assess ontogenetic
changes in the visual system, we conducted morphometric and histological analyses of the
eyes using specimens from New Zealand collections. While the ratio between eye diameter
and mantle length maintained a linear relationship throughout development, histological sections
of the retina revealed that the outer photoreceptor layer became proportionally longer
as the animal aged, coincident with a habitat shift into deeper, darker ocean strata. Other retinal
layers maintained the same absolute thickness as was observed in paralarvae. Granules
of the pigment ommin, normally located in the screening layer positioned at the base of
the photoreceptors, were also observed at the outer end of the photoreceptor segments
throughout the retina in young and mid-sized specimens. Early developmental stages of this
species, dwelling in shallow waters, may therefore rely on migratory ommin to help shield
photoreceptors from excess light and prevent over-stimulation. The oldest, deeper-dwelling
specimens of T. pellucida examined had longer photoreceptors, and little or no migrated
ommin was observed; we suggest therefore that short-term adaptive mechanisms for bright
light conditions may be used primarily during epipelagic, early life stages in this species
Targeted β-Phase Formation in Poly(fluorene)-Ureasil Grafted Organic-Inorganic Hybrids
© 2017 American Chemical Society. The development of synthetic strategies to control the molecular organization (and inherently linked optoelectronic properties) of conjugated polymers is critical for the development of efficient light-emitting devices. Here, we report a facile route using sol-gel chemistry to promote the formation of the β-phase through the covalent-grafting of poly[(9,9-dioctylfluorene)-co-(9,9-bis(8-hydroxyoctyl)fluorene)] (PFO-OH) to poly(oxyalkylene)/siloxane hybrids known as ureasils, due to the urea linkages binding the organic and inorganic components. Although grafting occurs within the siliceous domains, the degree of branching of the organic backbone determines the packing of the PFO-OH chains within the ureasil framework. Moreover, photoluminescence studies indicate that physical confinement also plays a key role in promoting the evolution of the β-phase of PFO-OH as the sol-gel transition proceeds. Spectroscopic and structural analyses reveal that dibranched ureasils promote linear packing of the PFO-OH chains, while tribranched ureasils exhibit a more open, distorted structure that restricts the packing efficacy and reduces the number of covalent anchorages. These results indicate that the organic-inorganic hybrid structure induces distinct levels of β-phase formation and that covalent grafting is a versatile approach to design novel poly(fluorene) hybrid materials with tailored optical properties
A comparison of health-related quality of life (health utility) between insulin degludec and insulin glargine: a meta-analysis of phase 3 trials
Aim: To evaluate health-related quality of life (health utility) scores in patients with diabetes receiving insulin degludec (IDeg) or insulin glargine (IGlar).
Methods: Patient-level data from six, randomized, controlled, open-label, multicentre, confirmatory, treat-to-target trials of 26- or 52 weeks' duration were pooled in this analysis. The Short Form 36 (SF-36) version-2 health questionnaire was completed by patients at baseline and end-of-trial. SF-36 scores for 4001 individual patients were then mapped onto the EuroQol-5D health utility scale, which has a range from −0.59 (a state worse than death) to 1.00 (perfect health).
Results: IDeg treatment exhibited a significant improvement in health status of 0.005 (CI: 0.0006; 0.009) points compared with IGlar (p < 0.024). Gender, region, trial and age also had a significant influence on estimated utility scores as did baseline utility scores, p < 0.05. Prior to the removal of interaction variables a difference of 0.008 points was observed, p < 0.045. Previous insulin treatment did not have an impact on the final outcome.
Conclusion: This study shows that IDeg is associated with a modest, but statistically significant, improvement in health utility compared with IGlar in patients with diabetes
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A fixed-target platform for serial femtosecond crystallography in a hydrated environment.
For serial femtosecond crystallography at X-ray free-electron lasers, which entails collection of single-pulse diffraction patterns from a constantly refreshed supply of microcrystalline sample, delivery of the sample into the X-ray beam path while maintaining low background remains a technical challenge for some experiments, especially where this methodology is applied to relatively low-ordered samples or those difficult to purify and crystallize in large quantities. This work demonstrates a scheme to encapsulate biological samples using polymer thin films and graphene to maintain sample hydration in vacuum conditions. The encapsulated sample is delivered into the X-ray beam on fixed targets for rapid scanning using the Roadrunner fixed-target system towards a long-term goal of low-background measurements on weakly diffracting samples. As a proof of principle, we used microcrystals of the 24 kDa rapid encystment protein (REP24) to provide a benchmark for polymer/graphene sandwich performance. The REP24 microcrystal unit cell obtained from our sandwiched in-vacuum sample was consistent with previously established unit-cell parameters and with those measured by us without encapsulation in humidified helium, indicating that the platform is robust against evaporative losses. While significant scattering from water was observed because of the sample-deposition method, the polymer/graphene sandwich itself was shown to contribute minimally to background scattering
Brain glucose sensing, glucokinase and neural control of metabolism and islet function.
It is increasingly apparent that the brain plays a central role in metabolic homeostasis, including the maintenance of blood glucose. This is achieved by various efferent pathways from the brain to periphery, which help control hepatic glucose flux and perhaps insulin-stimulated insulin secretion. Also, critically important for the brain given its dependence on a constant supply of glucose as a fuel--emergency counter-regulatory responses are triggered by the brain if blood glucose starts to fall. To exert these control functions, the brain needs to detect rapidly and accurately changes in blood glucose. In this review, we summarize some of the mechanisms postulated to play a role in this and examine the potential role of the low-affinity hexokinase, glucokinase, in the brain as a key part of some of this sensing. We also discuss how these processes may become altered in diabetes and related metabolic diseases.Funding and support from Wellcome Trust, Medical Research Council including the
Cambridge MRC Centre for Study of Obesity and Related Disorders (MRC-CORD), NIHR
Cambridge Biomedical Research Centre, Diabetes UK (RD05/003059) and Yousef Jameel
Fund).This is the final version published version. It first appeared at http://onlinelibrary.wiley.com/doi/10.1111/dom.12334/abstract
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Delivering evidence-based interventions for type 1 diabetes in the virtual world - A review of UK practice during the SARS-CoV-2 pandemic.
Funder: Abbott Diabetes CareFunder: SanofiFunder: Novo NordiskFunder: MedtronicAIMS: This review considers the impact of the SARS-CoV-2 pandemic on access to interventions for those living with type 1 diabetes and discusses the solutions which have been considered and actioned to ensure ongoing access care. METHODS: We performed a focussed review of the published literature, and the guidelines for changes that have been effected during the pandemic. We also drew from expert recommendations and information about local practice changes for areas where formal data have not been published. RESULTS: Evidence based interventions which support the achievement of improved glucose levels and/or reduction in hypoglycaemia include group structured education to support self-management, insulin pump therapy and continuous glucose monitoring. The SARS-CoV-2 pandemic had impacted the ability of diabetes services to deliver these intervention. Multiple adaptations have been put in place - transition to online delivery of education and care, and usage of diabetes technology. CONCLUSIONS: Although various adaptations have been made during the pandemic that have positively influenced uptake of services, there are many areas of delivery that need immediate improvement in the UK. We recommend a proactive approach in recognising the digital divide and inequity in distribution of these changes and we recommend introducing measures to reduce them
Delivering evidence-based interventions for type 1 diabetes in the virtual world - A review of UK practice during the SARS-CoV-2 pandemic.
Funder: Abbott Diabetes CareFunder: SanofiFunder: Novo NordiskFunder: MedtronicAIMS: This review considers the impact of the SARS-CoV-2 pandemic on access to interventions for those living with type 1 diabetes and discusses the solutions which have been considered and actioned to ensure ongoing access care. METHODS: We performed a focussed review of the published literature, and the guidelines for changes that have been effected during the pandemic. We also drew from expert recommendations and information about local practice changes for areas where formal data have not been published. RESULTS: Evidence based interventions which support the achievement of improved glucose levels and/or reduction in hypoglycaemia include group structured education to support self-management, insulin pump therapy and continuous glucose monitoring. The SARS-CoV-2 pandemic had impacted the ability of diabetes services to deliver these intervention. Multiple adaptations have been put in place - transition to online delivery of education and care, and usage of diabetes technology. CONCLUSIONS: Although various adaptations have been made during the pandemic that have positively influenced uptake of services, there are many areas of delivery that need immediate improvement in the UK. We recommend a proactive approach in recognising the digital divide and inequity in distribution of these changes and we recommend introducing measures to reduce them
Teachers’ Adoption of Embodied Learning Digital Games with an Inclusive Education Approach: Lessons Learnt from the INTELed Project in Spain
Producción CientÃficaEmbodied learning digital games have been used with success in the past to support students with special education needs, but their application by teachers in mainstream classes with an inclusive approach is still a challenge. This paper presents the results of a set of pilots in which a suite of embodied digital games was applied into pre-school and primary school classrooms. The findings of the studies provide insights into the conditions that facilitated and/or impeded the adoption of the technology by the participant teachers. These results are then elaborated to define a first set of strategies that could be used by third-party teachers to fulfill the same objectives, and to identify concrete design challenges for the application of embodied digital games in classrooms.Ministerio de Ciencia, Innovación y Universidades (Project TIN2017-85179-C3-2-R)Junta de Castilla y León (Project VA257P18 (CASSUALearn
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Ab initio structure prediction methods for battery materials a review of recent computational efforts to predict the atomic level structure and bonding in materials for rechargeable batteries
Portable electronic devices, electric vehicles and stationary energy storage applications, which encourage carbon-neutral energy alternatives, are driving demand for batteries that have concurrently higher energy densities, faster charging rates, safer operation and lower prices. These
demands can no longer be met by incrementally improving existing technologies but require the discovery of new materials with exceptional properties. Experimental materials discovery is both expensive and time consuming: before the efficacy of a new battery material can be assessed, its synthesis
and stability must be well-understood. Computational materials modelling can expedite this process by predicting novel materials, both in stand-alone theoretical calculations and in tandem with experiments. In this review, we describe a materials discovery framework based on density functional
theory (DFT) to predict the properties of electrode and solid-electrolyte materials and validate these predictions experimentally. First, we discuss crystal structure prediction using the Ab initio random structure searching (AIRSS) method. Next, we describe how DFT results allow us
to predict which phases form during electrode cycling, as well as the electrode voltage profile and maximum theoretical capacity. We go on to explain how DFT can be used to simulate experimentally measurable properties such as nuclear magnetic resonance (NMR) spectra and ionic conductivities.
We illustrate the described workflow with multiple experimentally validated examples: materials for lithium-ion and sodium-ion anodes and lithium-ion solid electrolytes. These examples highlight the power of combining computation with experiment to advance battery materials research.(1) Gates Cambridge Trust, University of Cambridge, UK
(2) EPSRC Centre for Doctoral Training in Computational Methods for Materials Science, UK, Grant No. EP/L015552/1.
(3) Winton Programme for the Physics of Sustainability, University of Cambridge, UK
(4) Sims Fund, University of Cambridge, UK
(5) EPSRC Grant No. EP/P003532/1
(6) EPSRC Collaborative Computational Projects on the Electronic Structure of Condensed Matter (CCP9), Grant No. EP/M022595/1, and NMR crystallography, Grant No. EP/M022501/1
(7) Computing resources on the Tier 1 resource ARCHER were provided through the UKCP EPSRC High-End computational consortium (EP/P022561/1) and on the Tier 2 resources HPC Midlands+ (EP/P020232/1) and CSD3 (EP/P020259/1)
Measuring diet in primary school children aged 8-11 years: validation of the Child and Diet Evaluation Tool (CADET) with an emphasis on fruit and vegetable intake.
Background/Objectives:The Child And Diet Evaluation Tool (CADET) is a 24-h food diary that measures the nutrition intake of children aged 3-7 years, with a focus on fruit and vegetable consumption. Until now CADET has not been used to measure nutrient intake of children aged 8-11 years. To ensure that newly assigned portion sizes for this older age group were valid, participants were asked to complete the CADET diary (the school and home food diary) concurrently with a 1-day weighed record. Subjects/Methods:A total of 67 children with a mean age of 9.3 years (s.d.: ± 1.4, 51% girls) participated in the study. Total fruit and vegetable intake in grams and other nutrients were extracted to compare the mean intakes from the CADET diary and Weighed record using t-tests and Pearson's r correlations. Bland-Altman analysis was also conducted to assess the agreement between the two methods. Results: Correlations comparing the CADET diary to the weighed record were high for fruit, vegetables and combined fruit and vegetables (r=0.7). The results from the Bland-Altman plots revealed a mean difference of 54 g (95% confidence interval: -88, 152) for combined fruit and vegetables intake. CADET is the only tool recommended by the National Obesity Observatory that has been validated in a UK population and provides nutrient level data on children's diets. Conclusions:The results from this study conclude that CADET can provide high-quality nutrient data suitable for evaluating intervention studies now for children aged 3-11 years with a focus on fruit and vegetable intake
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