Identification of highly active Fe sites in (Ni,Fe)OOH for electrocatalytic water splitting.

Highly active catalysts for the oxygen evolution reaction (OER) are required for the development of photoelectrochemical devices that generate hydrogen efficiently from water using solar energy. Here, we identify the origin of a 500-fold OER activity enhancement that can be achieved with mixed (Ni,Fe)oxyhydroxides (Ni(1-x)Fe(x)OOH) over their pure Ni and Fe parent compounds, resulting in one of the most active currently known OER catalysts in alkaline electrolyte. Operando X-ray absorption spectroscopy (XAS) using high energy resolution fluorescence detection (HERFD) reveals that Fe(3+) in Ni(1-x)Fe(x)OOH occupies octahedral sites with unusually short Fe-O bond distances, induced by edge-sharing with surrounding [NiO6] octahedra. Using computational methods, we establish that this structural motif results in near optimal adsorption energies of OER intermediates and low overpotentials at Fe sites. By contrast, Ni sites in Ni(1-x)Fe(x)OOH are not active sites for the oxidation of water.

Maternal, but not paternal, ratings of child preinjury functioning predict child posttraumatic stress.

Pretrauma internalizing and externalizing behaviors have been found to predict posttraumatic stress disorder (PTSD) symptoms (PTSS) in children following injury. However, child in-hospital self-report of pretrauma symptoms may be impacted by their injury and associated medical care (e.g., sedation/pain medications). Parental report of child pretrauma risk factors may be easier to capture; however, mothers and fathers differ in the extent to which they report, and agree on, internalizing versus externalizing behaviors in their child. The present study examined the differential utility of maternal versus paternal ratings of child preinjury internalizing, externalizing, and prosocial behaviors in predicting child PTSS 3- and 6-months postinjury. Eighty-four children were recruited from an emergency department after emergency medical services transport following injury, along with their parent(s). Dyadic (one parent and a child) analyses revealed that maternal reports of internalizing behaviors were significantly associated with child PTSS 3 months, F(5, 64) = 9.48, p < .001; ß = .44, p = .01, and 6 months, F(5, 48) = 5.57, p < .001; ß = .42, p = .03, postinjury. Paternal reports were not associated with child PTSS at either time point. In a subsample of triads (mother-father-child), mothers' and fathers' reports were only moderately correlated (rs = .30-.53), and neither maternal nor paternal ratings individually predicted child PTSS when both parents' reports were included in the model. Exploratory analyses revealed that family conflict and maternal initial PTSS moderated the relationship between maternal ratings of internalizing behaviors and child 3-month PTSS. Results suggest that maternal reports of child preinjury internalizing behaviors should be considered as predictors of later child PTSS development. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Frequency and correlates of suicidal ideation and behaviors in treatment-seeking Post-9/11 Veterans.

OBJECTIVE: Post-9/11 U.S. veterans and servicemembers are at increased risk for suicide, indicating an important need to identify and mitigate suicidal ideation and behaviors in this population. METHOD: Using data modeling techniques, we examined correlates of suicidal ideation and behavior at intake in 261 Post-9/11 veterans and servicemembers seeking mental health treatment. RESULTS: Our sample endorsed high rates of suicidal ideation and behavior. Approximately 40% of our sample scored in a range on the Suicide Behaviors Questionnaire-Revised (SBQ-R), indicating high clinical risk for suicide. Results from multivariate analyses indicate that greater state and/or trait depression severity, greater anger and anger expression, less impulse control, and lower rank were consistently associated with suicidal ideation and behavior across our models. Negative posttraumatic thoughts about the self, gender, and military branch of service were also significantly associated with suicidal ideation and behavior. CONCLUSIONS: Suicidal ideation and behaviors are common in veterans seeking mental health treatment. State and/or trait depression, anger and impulse control were predictors of increased risk for suicidal ideation and behavior across models. Consistencies and differences across models as well as limitations and practical implications for the findings are discussed.

Micro Versus Macro Processes: How specific stress exposure impacts sleep, affect, and risk-related behavior on the path to disease in high-risk adults.

BACKGROUND: The stress-to-disease association has been well-accepted for some time. However, the understanding of how stress exposure contributes to psychological disease progression remains unclear. OBJECTIVE: To test the real-time impact of variable stress exposure on risk-related clinical phenomena and affective disease progression in a high-risk sample of active-duty firefighters. METHODS: Participants completed weekly diaries reporting stressful event exposure, affect, sleep, and risk-related and healthy behaviors over six-months and were evaluated for lifetime and current psychiatric disease using clinical interviews before and after the sampling period. RESULTS: Stress exposure impacted clinical phenomena in differing ways. Major personal events and day-to-day hassles predicted health-impairing shifts in sleep and behavior that were associated with increases in symptoms and psychological distress over the 6-month period. In contrast, highly aversive incidents predicted greater adaptive behaviors that were uniquely predictive of symptom decreases over the six-month period. CONCLUSION: These findings shed new light on stress-to-disease processes, demonstrating how variable stress exposure influences critical shifts in behavior and sleep, contributing to psychological adjustment of firefighters over time. These data suggest practical ways to monitor risk in high-risk samples (e.g., monitoring sleep latency) and offer avenues for further explication of disease processes in real time.

Age moderates the relationship between source of social support and mental health in racial minority lesbian, gay, and bisexual youth.

We examined the relationship between source of social support and mental health (and the moderating impact of age) in 64 low socioeconomic status, racial minority lesbian, gay, and bisexual adolescents/young adults. Social support from family ( ß = -.302, p = .03; ß = -.364, p = .008), but not friends or significant others, was independently related to posttraumatic stress disorder and depression symptoms, respectively. Family social support was associated with lower posttraumatic stress disorder and depression symptoms in participants aged 16-19 years, while friend social support was associated with lower symptoms for participants aged over 20 years. Friend social support was also associated with lower posttraumatic stress disorder symptoms in participants aged 16-17 years. Interventions should target age-appropriate sources of social support.

Parental Factors Associated with Child Post-traumatic Stress Following Injury: A Consideration of Intervention Targets.

Post-traumatic stress disorder (PTSD) symptoms are relatively common following pediatric traumatic injury and are related to poor long-term child outcomes. However, due to concerns regarding the efficacy of early child preventive interventions, and difficulty intervening with injured and medicated children soon after the event, it is not feasible to provide early psychological interventions to children exposed to traumatic injury. Parental PTSD symptoms and reactions to the child's traumatic injury impact child outcomes and provide potential targets for early intervention to reduce child symptom development without involving the child. The authors conducted a review of the literature using Psycinfo and Pubmed research databases (publication years = 1990-2017) and identified 65 published studies relevant to the topic of the review. The present review considers parent factors [parenting styles, parental post-traumatic pathology (PTS), adaptive and maladaptive coping strategies, and communication regarding the traumatic injury] and their impact on child PTS. We focus specifically on factors amenable to intervention. We further review moderators of these relationships (e.g., child age and gender, parent gender) and conclude that it is unlikely that a one-size-fits-all approach to treatment will be successful. Rather, it is necessary to consider the age and gender of parent child dyads in designing and providing targeted interventions to families following the traumatic injury of a child.

Nanoscale Chemical Imaging of an Individual Catalyst Particle with Soft X-ray Ptychography.

Understanding Fe deposition in fluid catalytic cracking (FCC) catalysis is critical for the mitigation of catalyst degradation. Here we employ soft X-ray ptychography to determine at the nanoscale the distribution and chemical state of Fe in an aged FCC catalyst particle. We show that both particle swelling due to colloidal Fe deposition and Fe penetration into the matrix as a result of precracking of large organic molecules occur. The application of ptychography allowed us to provide direct visual evidence for these two distinct Fe-based deactivation mechanisms, which have so far been proposed only on the basis of indirect evidence.

Persistent State-of-Charge Heterogeneity in Relaxed, Partially Charged Li1- x Ni1/3 Co1/3 Mn1/3 O2 Secondary Particles.

Ex situ transmission X-ray microscopy reveals micrometer-scale state-of-charge heterogeneity in solid-solution Li1- x Ni1/3 Co1/3 Mn1/3 O2 secondary particles even after extensive relaxation. The heterogeneity generates overcharged domains at the cutoff voltage, which may accelerate capacity fading and increase impedance with extended cycling. It is proposed that optimized secondary structures can minimize the state-of-charge heterogeneity by mitigating the buildup of nonuniform internal stresses associated with volume changes during charge.

Mass-selected nanoparticles of PtxY as model catalysts for oxygen electroreduction.

Low-temperature fuel cells are limited by the oxygen reduction reaction, and their widespread implementation in automotive vehicles is hindered by the cost of platinum, currently the best-known catalyst for reducing oxygen in terms of both activity and stability. One solution is to decrease the amount of platinum required, for example by alloying, but without detrimentally affecting its properties. The alloy PtxY is known to be active and stable, but its synthesis in nanoparticulate form has proved challenging, which limits its further study. Herein we demonstrate the synthesis, characterization and catalyst testing of model PtxY nanoparticles prepared through the gas-aggregation technique. The catalysts reported here are highly active, with a mass activity of up to 3.05 A mgPt(-1) at 0.9 V versus a reversible hydrogen electrode. Using a variety of characterization techniques, we show that the enhanced activity of PtxY over elemental platinum results exclusively from a compressive strain exerted on the platinum surface atoms by the alloy core.