Manganese containing copper aluminate catalysts:Genesis of structures and active sites for hydrogenation of aldehydes

Copper aluminate spinel (CuO.CuAl2O4) is the favoured Cr-free substitute for the copper chromite catalyst (CuO.CuCr2O4) in the industrial hydrogenation of aldehydes. New insights in the catalytic mechanism were obtained by systematically studying the structure and activity of these catalysts including effects of manganese as a catalyst component. The hydrogenation of butyraldehyde to butanol was studied as a model reaction and the active structure was characterised using X-ray diffraction, temperature programmed reduction, N2O chemisorption, EXAFS and XANES, including in-situ investigations. The active catalyst is a reduced spinel lattice that is stabilised by protons, with copper metal nanoparticles grown upon its surface. Incorporation of Mn into the spinel lattice has a profound effect on the spinel structure. Mn stabilises the spinel towards reduction of CuII to Cu0 by occupation of tetrahedral sites with Mn cations, but also causes decreased catalytic activity. Structural data, combined with the effect on catalysis, indicate a predominantly interface-based reaction mechanism, involving both the spinel and copper nanoparticle surface in protonation and reduction of the aldehyde. The electron reservoir of the metallic copper particles is regenerated by the dissociative adsorption and oxidation of H2 on the metal surface. The generated protons are stored in the spinel phase, acting as proton reservoir. Cu(I) species located within the spinel and identified by XANES are probably not involved in the catalytic cycle

Reduced quasifission competition in fusion reactions forming neutron-rich heavy elements

Measurements of mass-angle distributions (MADs) for Cr + W reactions, providing a wide range in the neutron-to-proton ratio of the compound system, (N/Z)CN, have allowed for the dependence of quasifission on the (N/Z)CN to be determined in a model-independent way. Previous experimental and theoretical studies had produced conflicting conclusions. The experimental MADs reveal an increase in contact time and mass evolution of the quasifission fragments with increasing (N/Z)CN, which is indicative of an increase in the fusion probability. The experimental results are in agreement with microscopic time-dependent Hartree-Fock calculations of the quasifission process. The experimental and theoretical results favor the use of the most neutron-rich projectiles and targets for the production of heavy and superheavy nuclei.Comment: Accepted to PRC as a Rapid Communicatio

Parental alcohol use and risk of behavioral and emotional problems in offspring

Objective The majority of studies that have examined parental alcohol use and offspring outcomes have either focused on exposure in the antenatal period or from clinical populations. This study sought to examine proximal and distal associations between parental alcohol use and offspring conduct problems and depressive symptoms in a population birth cohort. Methods We used prospective data from a large UK based population cohort (ALSPAC) to investigate the association between parental alcohol use, measured in units, (assessed at ages 4 and 12 years) with childhood conduct trajectories, (assessed on six occasions from 4 to 13.5 years, n = 6,927), and adolescent depressive symptoms (assessed on four occasions from ~13 to ~18 years, n = 5,539). Heavy drinking was defined as ≥21 units per week in mothers and partners who drank 4+ units daily. Results We found little evidence to support a dose response association between parental alcohol use and offspring outcomes. For example, we found insufficient evidence to support an association between maternal alcohol use at age 4 years and childhood conduct problems (childhood limited: OR = 1.00, 95% CI = .99, 1.01; adolescent onset: OR = 0.99, 95% CI = .98, 1.00; and early-onset persistent: OR = 0.99, 95% CI = .98, 1.00) per 1-unit change in maternal alcohol use compared to those with low levels of conduct problems. We also found insufficient evidence to support an association between maternal alcohol use at age 4 years and adolescent depressive symptoms (intercept: b = .001, 95% CI = -.01, .01, and slope: b = .003, 95% CI = -.03, .03) per 1-unit change in maternal alcohol use. Results remained consistent across amount of alcohol consumed (i.e., number of alcohol units or heavy alcohol use), parent (maternal self-reports or maternal reports of partner’s alcohol use), and timing of alcohol use (assessed at age 4 or age 12 years). Conclusions There is no support for an association between parental alcohol use during childhood and conduct and emotional problems during childhood or adolescence

Priorities for research in child maltreatment, intimate partner violence and resilience to violence exposures:results of an international Delphi consensus development process

BACKGROUND: Intimate partner violence (IPV) and child maltreatment (CM) are major global public health problems. The Preventing Violence Across the Lifespan (PreVAiL) Research Network, an international group of over 60 researchers and national and international knowledge-user partners in CM and IPV, sought to identify evidence-based research priorities in IPV and CM, with a focus on resilience, using a modified Delphi consensus development process. METHODS: Review of existing empirical evidence, PreVAiL documents and team discussion identified a starting list of 20 priorities in the following categories: resilience to violence exposure (RES), CM, and IPV, as well as priorities that cross-cut the content areas (CC), and others specific to research methodologies (RM) in violence research. PreVAiL members (N = 47) completed two online survey rounds, and one round of discussions via three teleconference calls to rate, rank and refine research priorities. RESULTS: Research priorities were: to examine key elements of promising or successful programmes in RES/CM/IPV to build intervention pilot work; CC: to integrate violence questions into national and international surveys, and RM: to investigate methods for collecting and collating datasets to link data and to conduct pooled, meta and sub-group analyses to identify promising interventions for particular groups. CONCLUSIONS: These evidence-based research priorities, developed by an international team of violence, gender and mental health researchers and knowledge-user partners, are of relevance for prevention and resilience-oriented research in the areas of IPV and CM

Priorities for research in child maltreatment, intimate partner violence and resilience to violence exposures: results of an international Delphi consensus development process

Background Intimate partner violence (IPV) and child maltreatment (CM) are major global public health problems. The Preventing Violence Across the Lifespan (PreVAiL) Research Network, an international group of over 60 researchers and national and international knowledge-user partners in CM and IPV, sought to identify evidence-based research priorities in IPV and CM, with a focus on resilience, using a modified Delphi consensus development process. Methods Review of existing empirical evidence, PreVAiL documents and team discussion identified a starting list of 20 priorities in the following categories: resilience to violence exposure (RES), CM, and IPV, as well as priorities that cross-cut the content areas (CC), and others specific to research methodologies (RM) in violence research. PreVAiL members (N = 47) completed two online survey rounds, and one round of discussions via three teleconference calls to rate, rank and refine research priorities. Results Research priorities were: to examine key elements of promising or successful programmes in RES/CM/IPV to build intervention pilot work; CC: to integrate violence questions into national and international surveys, and RM: to investigate methods for collecting and collating datasets to link data and to conduct pooled, meta and sub-group analyses to identify promising interventions for particular groups. Conclusions These evidence-based research priorities, developed by an international team of violence, gender and mental health researchers and knowledge-user partners, are of relevance for prevention and resilience-oriented research in the areas of IPV and CM

Mendelian randomisation for mediation analysis: current methods and challenges for implementation

Mediation analysis seeks to explain the pathway(s) through which an exposure affects an outcome. Traditional, non-instrumental variable methods for mediation analysis experience a number of methodological difficulties, including bias due to confounding between an exposure, mediator and outcome and measurement error. Mendelian randomisation (MR) can be used to improve causal inference for mediation analysis. We describe two approaches that can be used for estimating mediation analysis with MR: multivariable MR (MVMR) and two-step MR. We outline the approaches and provide code to demonstrate how they can be used in mediation analysis. We review issues that can affect analyses, including confounding, measurement error, weak instrument bias, interactions between exposures and mediators and analysis of multiple mediators. Description of the methods is supplemented by simulated and real data examples. Although MR relies on large sample sizes and strong assumptions, such as having strong instruments and no horizontally pleiotropic pathways, our simulations demonstrate that these methods are unaffected by confounders of the exposure or mediator and the outcome and non-differential measurement error of the exposure or mediator. Both MVMR and two-step MR can be implemented in both individual-level MR and summary data MR. MR mediation methods require different assumptions to be made, compared with non-instrumental variable mediation methods. Where these assumptions are more plausible, MR can be used to improve causal inference in mediation analysis. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10654-021-00757-1

How does childhood maltreatment influence cardiovascular disease?:A sequential causal mediation analysis

BACKGROUND: Childhood maltreatment has been consistently associated with cardiovascular disease (CVD). However, the mechanisms of this relationship are not yet fully understood. We explored the relative contribution of anxiety/depression, smoking, body mass index (BMI) and inflammation (C-reactive protein, CRP) to the association between childhood maltreatment and CVD in men and women aged 40–69 years in the UK. METHODS: We used data from 40 596 men and 59 511 women from UK Biobank. To estimate the indirect effects of childhood maltreatment (physical, sexual and emotional abuse, and emotional and physical neglect) on incident CVD via each of the mediators, we applied a sequential mediation approach. RESULTS: All forms of maltreatment were associated with increased CVD risk [hazard ratios (HRs) ranging from 1.09 to 1.27]. Together, anxiety/depression, smoking, BMI and inflammation (indexed by CRP) mediated 26–90% of the association between childhood maltreatment and CVD, and the contribution of these mediators differed by type of maltreatment and sex. Anxiety/depression mediated the largest proportion of the association of sexual abuse, emotional abuse and emotional neglect with CVD (accounting for 16–43% of the total effect), especially in women. In men, BMI contributed the most to the indirect effect of associations of physical abuse and physical neglect with CVD; in women, anxiety/depression and BMI had similar contributions. CONCLUSIONS: These findings add to the understanding of how childhood maltreatment affects CVD risk and identify modifiable mediating factors that could potentially reduce the burden of CVD in people exposed to maltreatment in early life

Harsh parenting and child conduct and emotional problems:parent- and child-effects in the 2004 Pelotas Birth Cohort

In high-income countries, links between harsh and abusive parenting and child conduct and emotional problems are well-documented. However, less is known about these relationships in low- and middle-income countries, where harsh parenting may be more widely accepted and higher rates of conduct or emotional problems may exist which could influence the strength of these associations. We sought to investigate these relationships in a large population-based, prospective longitudinal study from Brazil, which also allowed us to test for sex differences. Using data from the 2004 Pelotas Birth Cohort Study (N = 4231) at ages 6 and 11 years, we applied cross-lagged path analysis to examine the relationships between harsh parenting (Conflict Tactics Scale Parent–Child version), and child conduct and emotional problems (Strengths and Difficulties Questionnaire). We found reciprocal relationships between harsh parenting and child conduct problems, with harsh parenting at age 6 predicting child conduct problems at age 11, and vice versa, even after adjusting for initial levels of conduct problems and harsh parenting, respectively. For child emotional problems, only unidirectional effects were found, with harsh parenting at age 6 predicting child emotional problems at age 11, after adjusting for initial levels of emotional problems, but not vice versa. No significant sex differences were observed in these relationships. These observations based on a middle-income country birth cohort highlight the potential universality of detrimental effects of harsh parenting on child conduct and emotional problems and affirm the importance of addressing parent- and child-effects in preventive and treatment interventions, especially those targeting conduct problems. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s00787-021-01759-w