Background
Proton radiotherapy (PRT) may be associated with less neurocognitive risk than photon RT (XRT) for pediatric brain tumor survivors. We compared neurocognitive and academic outcomes in ...long‐term survivors treated with XRT versus PRT.
Methods
Survivors underwent neurocognitive evaluation >1 year after craniospinal (CSI) or focal PRT or XRT. Groups were compared using separate one‐way analyses of covariance for the CSI and focal groups.
Results
PRT (n = 58) and XRT (n = 30) subgroups were similar on gender (66% male), age at RT (median = 6.5 years), age at follow‐up (median = 14.6 years), and government assistance status (32%). PRT and XRT focal groups differed on follow‐up interval, shunt history, and total RT dose (all p < .05), whereas PRT and XRT CSI groups differed on follow‐up interval, baseline neurocognitive performance score, boost volume, and CSI dose (all p < .05). The PRT focal group outperformed the XRT focal group on inhibition/switching (p = .04). The PRT CSI group outperformed the XRT CSI group on inattention/impulsivity (both p < .05). Several clinical variables (i.e., RT dose, boost field, baseline performance) predicted neurocognitive outcomes (all p < .05). The PRT focal group performed comparably to population means on most neurocognitive measures, while both CSI groups performed below expectation on multiple measures. The XRT CSI group was most impaired. All groups fell below expectation on processing speed, fine motor, and academic fluency (most p < .01).
Conclusions
Findings suggest generally favorable neurocognitive and academic long‐term outcomes following focal PRT. Impairment was greatest following CSI regardless of modality. Dosimetry and baseline characteristics are important determinants of outcome alone or in combination with modality.
Microphysiological and organ-on-chip platforms seek to address critical gaps in human disease models and drug development that underlie poor rates of clinical success for novel interventions. While ...the fabrication technology and model cells used to synthesize organs-on-chip have advanced considerably, most platforms rely on animal-derived or synthetic extracellular matrix as a cell substrate, limiting mimicry of human physiology and precluding use in modeling diseases in which matrix dynamics play a role in pathogenesis. Here, the development of human cell-derived matrix (hCDM) composite hydrogels for use in 3D microphysiologic models of the vasculature is reported. hCDM composite hydrogels are derived from human donor fibroblasts and maintain a complex milieu of basement membrane, proteoglycans, and nonfibrillar matrix components. The use of hCDM composite hydrogels as 2D and 3D cell culture substrates is demonstrated, and hCDM composite hydrogels are patterned to form engineered human microvessels. Interestingly, hCDM composite hydrogels are enriched in proteins associated with vascular morphogenesis as determined by mass spectrometry, and functional analysis demonstrates proangiogenic signatures in human endothelial cells cultured in these hydrogels. In conclusion, this study suggests that human donor-derived hCDM composite hydrogels could address technical gaps in human organs-on-chip development and serve as substrates to promote vascularization.
Developmental methylmercury (MeHg) exposure selectively targets the cerebral and cerebellar cortices, as seen by disruption of cytoarchitecture and glutamatergic (GLUergic) neuron hypoplasia. To ...begin to understand the mechanisms of this loss of GLUergic neurons, we aimed to develop a model of developmental MeHg neurotoxicity in human-induced pluripotent stem cells differentiating into cortical GLUergic neurons. Three dosing paradigms at 0.1 μM and 1.0 μM MeHg, which span different stages of neurodevelopment and reflect toxicologically relevant accumulation levels seen in human studies and mammalian models, were established. With these exposure paradigms, no changes were seen in commonly studied endpoints of MeHg toxicity, including viability, proliferation, and glutathione levels. However, MeHg exposure induced changes in mitochondrial respiration and glycolysis and in markers of neuronal differentiation. Our novel data suggests that GLUergic neuron hypoplasia seen with MeHg toxicity may be due to the partial inhibition of neuronal differentiation, given the increased expression of the early dorsal forebrain marker FOXG1 and corresponding decrease in expression on neuronal markers MAP2 and DCX and the deep layer cortical neuronal marker TBR1. Future studies should examine the persistent and latent functional effects of this MeHg-induced disruption of neuronal differentiation as well as transcriptomic and metabolomic alterations that may mediate MeHg toxicity.
•Human-induced pluripotent stem model of early developmental MeHg neurotoxicity.•Developmental MeHg causes changes in neuronal differentiation and energetics.•No Observed Adverse Effect Concentration (NOAEC) for MeHg cytotoxicity and GSH levels.•Neuron hypoplasia by MeHg may be due to inhibition of neuronal differentiation.
Acoustic spalling is a promising technique for substrate reuse in the fabrication of gallium arsenide (GaAs) photovoltaic cells. However, the acoustic spalling process can leave the substrate with ...areas of rough surface morphology that can interfere with subsequent cell growth and processing. In this work, we investigate the use of wet etchants to smooth the surface of acoustically spalled GaAs substrates. We evaluated six different etchants. Of those tested, an 8:1:1 mixture of sulfuric acid, hydrogen peroxide, and water at 30 <inline-formula><tex-math notation="LaTeX">^{\circ }</tex-math></inline-formula>C and a moderate stirring rate showed the greatest roughness reduction per mass loss while producing the desired morphology. This etchant was then applied to an acoustically spalled 2-inch GaAs wafer. A single-junction GaAs cell was then grown via metalorganic vapor-phase epitaxy on this substrate, an acoustic spalled substrate without a smoothing etch, and an epi-ready substrate. Use of the 8:1:1 <inline-formula><tex-math notation="LaTeX">\mathrm{H_{2}SO_{4}}\hbox{:}\mathrm{H_{2}O_{2}}\hbox{:}\mathrm{H_{2}O}</tex-math></inline-formula> etchant produced cells an average efficiency of 12.8% as compared to that of 2.0% grown on the unetched acoustically spalled substrate and 16.3% grown on the epi-ready substrate. The results of this work demonstrate that wet etching is a viable method for smoothing the surface of spalled GaAs substrates, paving the way for substrate reuse via acoustic spalling at efficiencies that approach growth on epi-ready substrates.
Abstract
Utilizing sunlight to directly perform photoelectrochemical reactions is a promising route to renewable, net carbon‐neutral fuels. However, a common problem with solar fuel production is ...semiconductor degradation in aqueous environments. An ideal protection layer should (1) prevent solution from reaching the semiconductor, (2) maintain charge transfer to and from solution, and (3) be transparent to light above the semiconductor band gap. While there have been substantial advances toward layers that meet these requirements, they are not easily adapted to new surfaces or new reactions, which can make protection difficult for newly developed photoabsorbers and (photo)electrochemical reaction pairings. In this work, we demonstrate the use of transparent conductive encapsulants (TCEs) to meet these requirements while also allowing for photoelectrode‐ and reaction‐agnostic adaptability. TCEs are composed of an ethyl‐vinyl acetate matrix with embedded conductive metal‐coated microspheres that can be laminated to semiconductors. First, the electrochemical behavior of TCE‐coated electrodes for the reduction of methyl viologen is characterized, demonstrating through‐TCE electrical conduction. Then, photoelectrochemical measurements on TCE‐protected semiconductors demonstrate the flexibility of this protection scheme. Finally, long‐term photoelectrochemical measurements probe the efficacy of TCEs as protection layers. These findings demonstrate the potential of TCEs as adaptable protection layers in various photoelectrochemical applications.
Abstract
Invited for this issue's Front Cover is a group of researchers from the Materials, Chemistry, and Computational Science Directorate at the National Renewable Energy Laboratory, led by Dr. ...Ann L. Greenaway. The front cover picture shows the surface of a TCE sheet, with the metallized spheres that act as conductive pathways from the semiconductor surface, through the polymer matrix, to the electrochemical interface. The rainbow represents the light going through the TCE layer to the semiconductor below. The primary electrochemical reaction used in this work was the first reduction of methyl viologen, as illustrated with the floating chemical structures. Cover design by Talysa Klein (
https://www.tk2.design/
). Read the full text of the Research Article at
10.1002/celc.202300209
.
As childhood obesity and poor nutrition rates in England continue to rise, parents and childcare practitioners have key partnership roles in ensuring young children have healthy balanced diets. Yet ...little is known about parents' understanding and involvement in their childcare settings' food decisions and practices, and how this might be strengthened. Semi-structured interviews were carried out with a purposive sample of 59 parents with one or more children attending early years settings in England. Framework analysis was used to explore the interviews. Epstein's model of parental partnerships was adapted as a reflective lens for the findings, and their implication for early years' policy and practice. Parents reported a lack of two-way communication on food, and of opportunities for active, meaningful engagement around food and healthy eating outside of one-to-one discussions of their child's specific needs and requirements. Some parents reported a lack of trust in the food related information provided by their childcare setting. As young children spend more time in formal childcare, it is increasingly important that trusting collaborative relationships are built between parents and childcare practitioners to ensure that children have the best start in life. This study adds to the limited literature on parental involvement in early years settings. Findings suggest that more policy work and development is needed in the early years sector, particularly in ensuring clear and accessible guidelines on food in early years settings are readily available, and that practitioners and parents have more clarity about their mutual roles and responsibilities in this.
The healthy context paradox, originally described with respect to school-level bullying interventions, refers to the generation of differences in mental wellbeing amongst those who continue to ...experience bullying even after interventions successfully reduce victimisation. Using data from the INCLUSIVE trial of restorative practice in schools, we relate this paradox to the need to theorise potential harms when developing interventions; formulate the healthy context paradox in a more general form defined by mediational relationships and cluster-level interventions; and propose two statistical models for testing the healthy context paradox informed by multilevel mediation methods, with relevance to structural and individual explanations for this paradox.
We estimated two multilevel mediation models with bullying victimisation as the mediator and mental wellbeing as the outcome: one with a school-level interaction between intervention assignment and the mediator; and one with a random slope component for the student-level mediator-outcome relationship predicted by school-level assignment. We relate each of these models to contextual or individual-level explanations for the healthy context paradox.
Neither model suggested that the INCLUSIVE trial represented an example of the healthy context paradox. However, each model has different interpretations which relate to a multilevel understanding of the healthy context paradox.
Greater exploration of intervention harms, especially when those accrue to population subgroups, is an essential step in better understanding how interventions work and for whom. Our proposed tests for the presence of a healthy context paradox provide the analytic tools to better understand how to support development and implementation of interventions that work for all groups in a population.
Current Controlled Trials, ISRCTN10751359 .
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
One of the design choices to be made when constructing photovoltaic modules from tandem solar cells is whether to use 2-, 3-, or 4-terminal tandem devices. Two-terminal (2T) cells are the simplest to ...interconnect, but for effective energy production the two subcells must be current-matched, which constrains the choice of materials for the component subcells. Three-terminal (3T) cells can be interconnected in voltage-matched configurations, which greatly increases the number of suitable subcell bandgap combinations, but with some additional cell interconnection complexity and losses. In principle, four-terminal (4T) cells provide the best power production, but in practice this will be mitigated by losses associated with the more complex interconnection requirements and shading losses necessitated by the need to laterally transport carriers between the cells. Many comparisons have been made between 2T and 4T configurations, mostly at the cell level. Here we provide a framework to assess the relative performance of 3T voltage-matched configurations relative to 2T and 4T approaches at the module level. We compare the energy production for both a fixed standard spectrum, and under variable outdoor conditions (accounting for spectrum, temperature, and location). The methods presented enable the comprehensive visualization and comparison of string-end losses, voltage matching ratios, and resistive and optical losses for tandems constructed out of any solar cell materials.
Energy production, rather than efficiency, is the most important metric for comparing different configurations of tandem solar cells (2T, 3T, 4T), as each interconnection technique has its own advantages and disadvantages.
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