30 research outputs found
PrFeO3 Photocathodes Prepared Through Spray Pyrolysis
Perovskite oxides are receiving wide interest for photocatalytic and photoelectrochemical devices, owing to their suitable band gaps for solar light absorption and stability in aqueous applications. Herein, we assess the activity of PrFeO3 photocathodes prepared by using spray pyrolysis and calcination temperatures between 500 and 700â°C. Scanning electron microscopy shows corrugated films of high surface coverage on the conductive glass substrate. The electrochemically active surface area shows slight decreases with temperature increases from 500 to 600 and 700â°C. However, transient photocurrent responses and impedance spectroscopy data showed that films calcined at higher temperatures reduced the probabilities of recombination due to trap states, resulting in faster rates of charge extraction. In this tradeâoff, a calcination temperature of 600â°C provided a maximum photocurrent of â130±4â
ÎŒAâcmâ2 at +0.43â
VRHE under simulated sunlight, with an incident photonâtoâcurrent conversion efficiency of 6.6â% at +0.61â
VRHE and 350â
nm and an onset potential of +1.4â
VRHE for cathodic photocurrent
Extraversion and Reward-Processing: Consolidating Evidence from an Electroencephalographic Index of Reward-Prediction-Error
Trait extraversion has been theorized to emerge from functioning of the dopaminergic reward system. Recent evidence for this view shows that extraversion modulates the scalp-recorded Reward Positivity, a putative marker of dopaminergic signaling of reward-prediction-error. We attempt to replicate this association amid several improvements on previous studies in this area, including an adequately-powered sample (Nâ=â100) and thorough examination of convergent-divergent validity. Participants completed a passive associative learning task presenting rewards and non-rewards that were either predictable or unexpected. Frequentist and Bayesian analyses confirmed that the scalp recorded Reward Positivity (i.e. the Feedback-Related-Negativity contrasting unpredicted rewards and unpredicted non-rewards) was significantly associated with three measures of extraversion and unrelated to other basic traits from the Big Five personality model. Narrower sub-traits of extraversion showed similar, though weaker associations with the Reward Positivity. These findings consolidate previous evidence linking extraversion with a putative marker of dopaminergic reward-processing
Dopamine transporter genotype is associated with a lateralized resistance to distraction during attention selection
Although lateral asymmetries in orienting behavior are evident across species and have been linked to interhemispheric asymmetries in dopamine signaling, the relative contribution of attentional versus motoric processes remains unclear. Here we took a cognitive genetic approach to adjudicate between roles for dopamine in attentional versus response selection. A sample of nonclinical adult humans (N = 518) performed three cognitive tasks (spatial attentional competition, spatial cueing, and flanker tasks) that varied in the degree to which they required participants to resolve attentional or response competition. All participants were genotyped for two putatively functional tandem repeat polymorphisms of the dopamine transporter gene (DAT1; SLC6A3), which are argued to influence the level of available synaptic dopamine and confer risk to disorders of inattention. DAT1 genotype modulated the task-specific effects of the various task-irrelevant stimuli across both the spatial competition and spatial cueing but not flanker tasks. Specifically, compared with individuals carrying one or two copies of the 10-repeat DAT1 allele, individuals without this allele demonstrated an immunity to distraction, such that response times were unaffected by increases in the number of distractor stimuli, particularly when these were presented predominantly in the left hemifield. All three genotype groups exhibited uniform costs of resolving leftward response selection in a standard flanker task. None of these significant effects could be explained by speedâaccuracy trade-offs, suggesting that participants without the 10-repeat allele of the DAT1 tandem repeat polymorphism possess an enhanced attentional ability to suppress task-irrelevant stimuli in the left hemifield
Interventions to treat pain in paediatric CFS/ME: A systematic review
Background Paediatric chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is common (prevalence 1%-2%). Two-thirds of children experience moderate or severe pain, which is associated with increased fatigue and poorer physical function. However, we do not know if treatment for CFS/ME improves pain. Objective Identify whether specialist treatment of paediatric CFS/ME improves pain. Methods We conducted a detailed search in MEDLINE, EMBASE, PsycINFO and the Cochrane Library. Two researchers independently screened texts published between 1994 and 24 January 2019 with no language restrictions. Inclusion criteria were (1) randomised controlled trials and observational studies; (2) participants aged <19 years with CFS/ME; and (3) measure of pain before and after an intervention. Results Of 1898 papers screened, 26 studies investigated treatment for paediatric CFS/ME, 19 of which did not measure pain at any time point. Only five treatment studies measured pain at baseline and follow-up and were included in this review. None of the interventions were specifically targeted at treating pain. Of the included studies, two showed no improvement in pain scores, one suggested an improvement in one subgroup and two studies identified improvements in pain measures in 'recovered' patients compared with 'non-recovered' patients. Conclusions Despite the prevalence and impact of pain in children with CFS/ME surprisingly few treatment studies measured pain. In those that did measure pain, the treatments used focused on overall management of CFS/ME and we identified no treatments that were targeted specifically at managing pain. There is limited evidence that treatment helps improve pain scores. However, patients who recover appear to have less pain than those who do not recover. More studies are needed to determine if pain in paediatric CFS/ME requires a specific treatment approach, with a particular focus on patients who do not recover following initial treatment. PROSPERO registration number CRD42019117540
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Executive functioning, motor difficulties and developmental coordination disorder
The current study assessed a comprehensive range of executive functions (EFs) in children with poor motor skills, comparing profiles of children with a diagnosis of developmental coordination disorder (DCD) and those identified with motor difficulties (MD). Children in both groups performed more poorly than typically-developing controls on nonverbal measures of working memory, inhibition, planning and fluency, but not on tests of switching. The similar patterns of strengths and weaknesses in children with MD and DCD have important implications for parents, teachers and clinicians, as children with MD may struggle with EF tasks even though their motor difficulties are not identified
Deliberative Ecologies:Complexity and Social-Ecological Dynamics in International Environmental Negotiations
Genomic investigations of unexplained acute hepatitis in children
Since its first identification in Scotland, over 1,000 cases of unexplained paediatric hepatitis in children have been reported worldwide, including 278 cases in the UK1. Here we report an investigation of 38 cases, 66 age-matched immunocompetent controls and 21 immunocompromised comparator participants, using a combination of genomic, transcriptomic, proteomic and immunohistochemical methods. We detected high levels of adeno-associated virus 2 (AAV2) DNA in the liver, blood, plasma or stool from 27 of 28 cases. We found low levels of adenovirus (HAdV) and human herpesvirus 6B (HHV-6B) in 23 of 31 and 16 of 23, respectively, of the cases tested. By contrast, AAV2 was infrequently detected and at low titre in the blood or the liver from control children with HAdV, even when profoundly immunosuppressed. AAV2, HAdV and HHV-6 phylogeny excluded the emergence of novel strains in cases. Histological analyses of explanted livers showed enrichment for T cells and B lineage cells. Proteomic comparison of liver tissue from cases and healthy controls identified increased expression of HLA class 2, immunoglobulin variable regions and complement proteins. HAdV and AAV2 proteins were not detected in the livers. Instead, we identified AAV2 DNA complexes reflecting both HAdV-mediated and HHV-6B-mediated replication. We hypothesize that high levels of abnormal AAV2 replication products aided by HAdV and, in severe cases, HHV-6B may have triggered immune-mediated hepatic disease in genetically and immunologically predisposed children
Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19
IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19.
Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19.
DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 nonâcritically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022).
INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (nâ=â257), ARB (nâ=â248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; nâ=â10), or no RAS inhibitor (control; nâ=â264) for up to 10 days.
MAIN OUTCOMES AND MEASURES The primary outcome was organ supportâfree days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes.
RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ supportâfree days among critically ill patients was 10 (â1 to 16) in the ACE inhibitor group (nâ=â231), 8 (â1 to 17) in the ARB group (nâ=â217), and 12 (0 to 17) in the control group (nâ=â231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ supportâfree days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively).
CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes.
TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570