Minimizing the impacts of the ammonia economy on the nitrogen cycle and climate.

Ammonia (NH3) is an attractive low-carbon fuel and hydrogen carrier. However, losses and inefficiencies across the value chain could result in reactive nitrogen emissions (NH3, NOx, and N2O), negatively impacting air quality, the environment, human health, and climate. A relatively robust ammonia economy (30 EJ/y) could perturb the global nitrogen cycle by up to 65 Mt/y with a 5% nitrogen loss rate, equivalent to 50% of the current global perturbation caused by fertilizers. Moreover, the emission rate of nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting molecule, determines whether ammonia combustion has a greenhouse footprint comparable to renewable energy sources or higher than coal (100 to 1,400 gCO2e/kWh). The success of the ammonia economy hence hinges on adopting optimal practices and technologies that minimize reactive nitrogen emissions. We discuss how this constraint should be included in the ongoing broad engineering research to reduce environmental concerns and prevent the lock-in of high-leakage practices.

The technological and economic prospects for CO2 utilization and removal.

The capture and use of carbon dioxide to create valuable products might lower the net costs of reducing emissions or removing carbon dioxide from the atmosphere. Here we review ten pathways for the utilization of carbon dioxide. Pathways that involve chemicals, fuels and microalgae might reduce emissions of carbon dioxide but have limited potential for its removal, whereas pathways that involve construction materials can both utilize and remove carbon dioxide. Land-based pathways can increase agricultural output and remove carbon dioxide. Our assessment suggests that each pathway could scale to over 0.5 gigatonnes of carbon dioxide utilization annually. However, barriers to implementation remain substantial and resource constraints prevent the simultaneous deployment of all pathways.

Charting C-C coupling pathways in electrochemical CO2 reduction on Cu(111) using embedded correlated wavefunction theory.

The electrochemical CO2 reduction reaction (CO2RR) powered by excess zero-carbon-emission electricity to produce especially multicarbon (C2+) products could contribute to a carbon-neutral to carbon-negative economy. Foundational to the rational design of efficient, selective CO2RR electrocatalysts is mechanistic analysis of the best metal catalyst thus far identified, namely, copper (Cu), via quantum mechanical computations to complement experiments. Here, we apply embedded correlated wavefunction (ECW) theory, which regionally corrects the electron exchange-correlation error in density functional theory (DFT) approximations, to examine multiple C-C coupling steps involving adsorbed CO (*CO) and its hydrogenated derivatives on the most ubiquitous facet, Cu(111). We predict that two adsorbed hydrogenated CO species, either *COH or *CHO, are necessary precursors for C-C bond formation. The three kinetically feasible pathways involving these species yield all three possible products: *COH-CHO, *COH-*COH, and *OCH-*OCH. The most kinetically favorable path forms *COH-CHO. In contrast, standard DFT approximations arrive at qualitatively different conclusions, namely, that only *CO and *COH will prevail on the surface and their C-C coupling paths produce only *COH-*COH and *CO-*CO, with a preference for the first product. This work demonstrates the importance of applying qualitatively and quantitatively accurate quantum mechanical method to simulate electrochemistry in order ultimately to shed light on ways to enhance selectivity toward C2+ product formation via CO2RR electrocatalysts.

Caesarean section and anal incontinence in women after obstetric anal sphincter injury: A systematic review and meta-analysis.

BACKGROUND: Approximately 50% women who give birth after obstetric anal sphincter injury (OASI) develop anal incontinence (AI) over their lifetime. OBJECTIVE: To evaluate current evidence for a protective benefit of planned caesarean section (CS) to prevent AI after OASI. SEARCH STRATEGY: MEDLINE/PubMed, Embase 1974-2024, CINAHL and Cochrane to 7 February 2024 (PROSPERO CRD42022372442). SELECTION CRITERIA: All studies reporting outcomes after OASI and a subsequent birth, by any mode. DATA COLLECTION AND ANALYSIS: Eighty-six of 2646 screened studies met inclusion criteria, with nine studies suitable to meta-analyse the primary outcome of 'adjusted AI' after OASI and subsequent birth. Subgroups: short-term AI, long-term AI, AI in asymptomatic women. SECONDARY OUTCOMES: total AI, quality of life, satisfaction/regret, solid/liquid/flatal incontinence, faecal urgency, AI in women with and without subsequent birth, change in AI pre- to post- subsequent birth. MAIN RESULTS: There was no evidence of a difference in adjusted AI after subsequent vaginal birth compared with CS after OASI across all time periods (OR = 0.92, 95% CI 0.72-1.20; 9 studies, 2104 participants, I2 = 0% p = 0.58), for subgroup analyses or secondary outcomes. There was no evidence of a difference in AI in women with or without subsequent birth (OR = 1.00 95% CI 0.65-1.54; 10 studies, 970 participants, I2 = 35% p = 0.99), or pre- to post- subsequent birth (OR = 0.79 95% CI 0.51-1.25; 13 studies, 5496 participants, I2 = 73% p = 0.31). CONCLUSIONS: Due to low evidence quality, we are unable to determine whether planned caesarean is protective against AI after OASI. Higher quality evidence is required to guide personalised decision-making for asymptomatic women and to determine the effect of subsequent birth mode on long-term AI outcomes.

Strongly facet-dependent activity of iron-doped ß-nickel oxyhydroxide for the oxygen evolution reaction.

Iron (Fe)-doped ß-nickel oxyhydroxide (ß-NiOOH) is a highly active, noble-metal-free electrocatalyst for the oxygen evolution reaction (OER), with the latter being the bottleneck in electrochemical water splitting for sustainable hydrogen production. The mechanisms underlying how the Fe dopant modulates this host material's water electro-oxidation activity are still not entirely clear. Here, we combine hybrid density functional theory (DFT) and Hubbard-corrected DFT to investigate the OER activity of the most thermodynamically favorable (and therefore, expected to be the majority) crystallographic facets of ß-NiOOH, namely (0001) and (101̄0). By considering active sites involving both oxidation and reduction of the transition-metal active center during the redox cycle on these two different facets, we show that six-fold-lattice-coordinated Fe in ß-NiOOH is redox inactive towards both oxidation and reduction while five-fold-lattice-coordinated Fe in ß-NiOOH does exhibit redox activity. However, the determined redox activity of Fe (or lack of it) is not indicative of good (or bad) performance as a dopant on these two facets. Three of the four active sites investigated (oxo and hydroxo sites on (0001) and a hydrated site on (101̄0)) exhibit only a marginal (<0.1 V) decrease or increase in the thermodynamic overpotential upon doping with Fe. Only one of the redox-active sites investigated, the hydroxo site on (101̄0), exhibits a large attenuation in the thermodynamic overpotential upon doping (to ∼0.52 V from 0.86 V), although the doped overpotential is larger than that observed experimentally for Fe-doped NiOOH. Thus, although pure ß-NiOOH facets containing four-, five-, or six-fold lattice-coordinated Ni sites have roughly equal OER activities, yielding similar OER onset potentials (shown in A. Govind Rajan, J. M. P. Martirez and E. A. Carter, J. Am. Chem. Soc., 2020, 142, 3600-3612), only those facets containing four-fold lattice-coordinated Fe (e.g., as shown in J. M. P. Martirez and E. A. Carter, J. Am. Chem. Soc., 2019, 141, 693-705) would be active under analogous conditions for the Fe-doped material. It follows that, while undoped ß-NiOOH demonstrates a roughly facet-independent oxygen evolution activity, the activity of Fe-doped ß-NiOOH strongly depends on the crystallographic facet. Our study further motivates the investigation of strategies for the selective growth of facets with low iron coordination number to enhance the water splitting activity of Fe-doped ß-NiOOH.

Hot carrier multiplication in plasmonic photocatalysis.

Light-induced hot carriers derived from the surface plasmons of metal nanostructures have been shown to be highly promising agents for photocatalysis. While both nonthermal and thermalized hot carriers can potentially contribute to this process, their specific role in any given chemical reaction has generally not been identified. Here, we report the observation that the H2-D2 exchange reaction photocatalyzed by Cu nanoparticles is driven primarily by thermalized hot carriers. The external quantum yield shows an intriguing S-shaped intensity dependence and exceeds 100% for high light intensities, suggesting that hot carrier multiplication plays a role. A simplified model for the quantum yield of thermalized hot carriers reproduces the observed kinetic features of the reaction, validating our hypothesis of a thermalized hot carrier mechanism. A quantum mechanical study reveals that vibrational excitations of the surface Cu-H bond is the likely activation mechanism, further supporting the effectiveness of low-energy thermalized hot carriers in photocatalyzing this reaction.

Application of an opioid use disorder cascade of care in a large public health system.

Background: Over the past decade, hospitals and health systems have increasingly adopted interventions to address the needs of patients with substance use disorders. The Opioid Use Disorder (OUD) Cascade of Care provides a framework for organizing and tracking patient health milestones over time and can assist health systems in identifying areas of intervention to maximize the impact of evidence-based services. However, detailed protocols are needed to guide health systems in how to operationalize the OUD Cascade and track outcomes using electronic health records.Objective: In this paper, we describe the process of operationalizing and applying the OUD Cascade in a large, urban, public hospital system.Methods: Through this case example, we describe the technical processes around data mining, as well as the decision-making processes, challenges encountered, lessons learned from compiling preliminary patient data and defining stages and outcome measures for the OUD Cascade of Care, and preliminary dataResults: We identified 33,616 (26.17% female) individuals with an OUD diagnosis. Almost half (48%) engaged with addiction services, while only 10.7% initiated medication-based treatment in an outpatient setting, 6.7% had timely follow-up, and 3.5% were retained for a minimum of 6 months.Conclusion: The current paper serves as a primer for other health systems seeking to implement data-informed approaches to guide more efficient care and improved substance use-related outcomes. An OUD Cascade of Care must be tailored to local systems based on inherent data limitations and services design with an emphasis on early stages wherein drop-off is the greatest.

Probing pH-Dependent Dehydration Dynamics of Mg and Ca Cations in Aqueous Solutions with Multi-Level Quantum Mechanics/Molecular Dynamics Simulations.

The dehydration of aqueous calcium and magnesium cations is the most fundamental process controlling their reactivity in chemical and biological phenomena, such as the formation of ionic solids or passing through ion channels. It holds particular relevance in light of recent advancements in the development of carbon capture techniques that rely on mineralization for long-term carbon storage. Specifically, dehydration of Ca2+ and Mg2+ is a key step in proposed carbon capture processes aiming to exploit the relatively high concentration of dissolved carbon dioxide in seawater via the formation of carbonate minerals from solvated Ca2+ and Mg2+ cations for sequestration and storage. Nevertheless, atomic-scale understanding of the dehydration of aqueous Ca2+ and Mg2+ cations remains limited. Here, we utilize rare event sampling via density functional theory molecular dynamics and embedded wavefunction theory calculations to elucidate the dehydration dynamics of aqueous Ca2+ and Mg2+. Emphasis is placed on the investigation of the effect pH has on the stability of the different coordination environments. Our results reveal significant differences in the dehydration dynamics of the two cations and provide insight into how they may be modulated by pH changes.

Solvent Dynamics Are Critical to Understanding Carbon Dioxide Dissolution and Hydration in Water.

Simulations of carbon dioxide (CO2) in water may aid in understanding the impact of its accumulation in aquatic environments and help advance technologies for carbon capture and utilization (via, e.g., mineralization). Quantum mechanical (QM) simulations based on static molecular models with polarizable continuum solvation poorly reproduce the energetics of CO2 hydration to form carbonic acid in water, independent of the level of QM theory employed. Only with density-functional-theory-based molecular dynamics and rare-event sampling, followed by energy corrections based on embedded correlated wavefunction theory (in conjunction with density functional embedding theory), can a close agreement between theory and experiment be achieved. Such multilevel simulations can serve as benchmarks for simpler, less costly models, giving insight into potential errors of the latter. The strong influence of sampling/averaging over dynamical solvent configurations on the energetics stems from the difference in polarity of both the transition state and product (both polar) versus the reactant (nonpolar). When a solute undergoes a change in polarity during reaction, affecting its interaction with the solvent, careful assessment of the energetic contribution of the solvent response to this change is critical. We show that static models (without structural sampling) that incorporate three explicit water molecules can yield far superior results than models with more explicit water molecules because fewer water molecules yield less configurational artifacts. Static models intelligently incorporating both explicit (molecules directly participating in the reaction) and implicit solvation, along with a proper QM theory, e.g., CCSD(T) for closed-shell systems, can close the accuracy gap between static and dynamic models.

Highly Selective Electrochemical Reduction of CO2 into Methane on Nanotwinned Cu.

The electrochemical carbon dioxide reduction reaction (CO2RR) is a promising route to close the carbon cycle by reducing CO2 into valuable fuels and chemicals. Electrocatalysts with high selectivity toward a single product are economically desirable yet challenging to achieve. Herein, we demonstrated a highly (111)-oriented Cu foil electrocatalyst with dense twin boundaries (TB) (tw-Cu) that showed a high Faradaic efficiency of 86.1 ± 5.3% toward CH4 at -1.2 ± 0.02 V vs the reversible hydrogen electrode. Theoretical studies suggested that tw-Cu can significantly lower the reduction barrier for the rate-determining hydrogenation of CO compared to planar Cu(111) under working conditions, which suppressed the competing C-C coupling, leading to the experimentally observed high CH4 selectivity.

Gene-by-Environment Interaction Effects of Social Adversity on Externalizing Behavior in ABCD Youth.

This study tested whether multiple domains of social adversity, including neighborhood opportunity/deprivation and life stress, moderate genetic (A), common environmental (C), and unique environmental (E) influences on externalizing behaviors in 760 same-sex twin pairs (332 monozygotic; 428 dizygotic) ages 10-11 from the ABCD Study. Proportion of C influences on externalizing behavior increased at higher neighborhood adversity (lower overall opportunity). A decreased and C and E increased at lower levels of educational opportunity. A increased at lower health-environment and social-economic opportunity levels. For life stress, A decreased and E increased with number of experienced events. Results for educational opportunity and stressful life experiences suggest a bioecological gene-environment interaction pattern such that environmental influences predominate at higher levels of adversity, whereas limited access to healthcare, housing, and employment stability may potentiate genetic liability for externalizing behavior via a diathesis-stress mechanism. More detailed operationalization of social adversity in gene-environment interaction studies is needed.

Introducing the embedded random phase approximation: H2 dissociative adsorption on Cu(111) as an exemplar.

The random phase approximation (RPA) as a means of treating electron correlation recently has been shown to outperform standard density functional theory (DFT) approximations in a variety of cases. However, the computational cost of the RPA is substantially more than DFT, especially when aiming to study extended surfaces. Properly accounting for sufficient surface ensemble size, Brillouin zone sampling, and vacuum separation of periodic images in standard periodic-planewave-based DFT code raises the cost to achieve converged results. Here, we show that sub-system embedding schemes enable use of the RPA for modeling heterogeneous reactions at reduced computational cost. We explore two different embedded RPA (emb-RPA) approaches, periodic emb-RPA and cluster emb-RPA. We use the (experimentally and theoretically) well-studied H2 dissociative adsorption on Cu(111) as our exemplar, and first perform full periodic RPA calculations as a benchmark. The full RPA results match well the semi-empirical barrier fit to experimental observables and others derived from high-level computations, e.g., from recent embedded n-electron valence second order perturbation theory [Zhao et al., J. Chem. Theory Comput. 16(11), 7078-7088 (2020)] and quantum Monte Carlo [Doblhoff-Dier et al., J. Chem. Theory Comput. 13(7), 3208-3219 (2017)] simulations. Among the two emb-RPA approaches tested, the cluster emb-RPA accurately reproduces the energy profile (maximum error of 50 meV along the reaction pathway) while reducing the computational cost by approximately two orders of magnitude. We therefore expect that the embedded cluster approach will enable wider RPA implementation in heterogeneous catalysis.

Single-incision sling operations for urinary incontinence in women.

BACKGROUND: Stress urinary incontinence imposes a significant health and economic burden on individuals and society. Single-incision slings are a minimally-invasive treatment option for stress urinary incontinence. They involve passing a short synthetic device through the anterior vaginal wall to support the mid-urethra. The use of polypropylene mesh in urogynaecology, including mid-urethral slings, is restricted in many countries. This is a review update (previous search date 2012). OBJECTIVES: To assess the effects of single-incision sling operations for treating urinary incontinence in women, and to summarise the principal findings of relevant economic evaluations. SEARCH METHODS: We searched the Cochrane Incontinence Specialised Register, which contains trials identified from: CENTRAL, MEDLINE, MEDLINE In-Process, MEDLINE Epub Ahead of Print, and two trials registers. We handsearched journals, conference proceedings, and reference lists of relevant articles to 20 September 2022. SELECTION CRITERIA: We included randomised or quasi-randomised controlled trials in women with stress (or stress-predominant mixed) urinary incontinence in which at least one, but not all, trial arms included a single-incision sling. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methodological procedures. The primary outcome was subjective cure or improvement of urinary incontinence. MAIN RESULTS: We included 62 studies with a total of 8051 women in this review. We did not identify any studies comparing single-incision slings to no treatment, conservative treatment, colposuspension, or laparoscopic procedures. We assessed most studies as being at low or unclear risk of bias, with five studies at high risk of bias for outcome assessment. Sixteen trials used TVT-Secur, a single-incision sling withdrawn from the market in 2013. The primary analysis in this review excludes trials using TVT-Secur. We report separate analyses for these trials, which did not substantially alter the effect estimates. We identified two cost-effectiveness analyses and one cost-minimisation analysis. Single-incision sling versus autologous fascial sling One study (70 women) compared single-incision slings to autologous fascial slings. It is uncertain if single-incision slings have any effect on risk of dyspareunia (painful sex) or mesh exposure, extrusion or erosion compared with autologous fascial slings. Subjective cure or improvement of urinary incontinence at 12 months, patient-reported pain at 24 months or longer, number of women with urinary retention, quality of life at 12 months and the number of women requiring repeat continence surgery or sling revision were not reported for this comparison. Single-incision sling versus retropubic sling Ten studies compared single-incision slings to retropubic slings. There may be little to no difference between single-incision slings and retropubic slings in subjective cure or improvement of incontinence at 12 months (risk ratio (RR) 0.99, 95% confidence interval (CI) 0.91 to 1.07; 2 trials, 297 women; low-certainty evidence). It is uncertain whether single-incision slings increase the risk of mesh exposure, extrusion or erosion compared with retropubic minimally-invasive slings; the wide confidence interval is consistent with both benefit and harm (RR 1.55, 95% CI 0.24 to 9.82; 3 trials, 267 women; low-certainty evidence). It is uncertain whether single-incision slings lead to fewer women having postoperative urinary retention compared with retropubic slings; the wide confidence interval is consistent with possible benefit and harm (RR 0.47, 95% CI 0.12 to 1.84; 2 trials, 209 women; low-certainty evidence). The effect of single-incision slings on the risk of repeat continence surgery or mesh revision compared with retropubic slings is uncertain (RR 4.19, 95% CI 0.31 to 57.28; 2 trials, 182 women; very low-certainty evidence). One study reported quality of life, but not in a suitable format for analysis. Patient-reported pain at more than 24 months and the number of women with dyspareunia were not reported for this comparison. We downgraded the evidence due to concerns about risks of bias, imprecision and inconsistency. Single-incision sling versus transobturator sling Fifty-one studies compared single-incision slings to transobturator slings. The evidence ranged from high to low certainty. There is no evidence of a difference in subjective cure or improvement of incontinence at 12 months when comparing single-incision slings with transobturator slings (RR 1.00, 95% CI 0.97 to 1.03; 17 trials, 2359 women; high-certainty evidence). Single-incision slings probably have a reduced risk of patient-reported pain at 24 months post-surgery compared with transobturator slings (RR 0.12, 95% CI 0.02 to 0.68; 2 trials, 250 women; moderate-certainty evidence). The effect of single-incision slings on the risk of dyspareunia is uncertain compared with transobturator slings, as the wide confidence interval is consistent with possible benefit and possible harm (RR 0.78, 95% CI 0.41 to 1.48; 8 trials, 810 women; moderate-certainty evidence). There are a similar number of mesh exposures, extrusions or erosions with single-incision slings compared with transobturator slings (RR 0.61, 95% CI 0.39 to 0.96; 16 trials, 2378 women; high-certainty evidence). Single-incision slings probably result in similar or reduced cases of postoperative urinary retention compared with transobturator slings (RR 0.68, 95% CI 0.47 to 0.97; 23 trials, 2891 women; moderate-certainty evidence). Women with single-incision slings may have lower quality of life at 12 months compared to transobturator slings (standardised mean difference (SMD) 0.24, 95% CI 0.09 to 0.39; 8 trials, 698 women; low-certainty evidence). It is unclear whether single-incision slings lead to slightly more women requiring repeat continence surgery or mesh revision compared with transobturator slings (95% CI consistent with possible benefit and harm; RR 1.42, 95% CI 0.94 to 2.16; 13 trials, 1460 women; low-certainty evidence). We downgraded the evidence due to indirectness, imprecision and risks of bias. AUTHORS' CONCLUSIONS: Single-incision sling operations have been extensively researched in randomised controlled trials. They may be as effective as retropubic slings and are as effective as transobturator slings for subjective cure or improvement of stress urinary incontinence at 12 months. It is uncertain if single-incision slings lead to better or worse rates of subjective cure or improvement compared with autologous fascial slings. There are still uncertainties regarding adverse events and longer-term outcomes. Therefore, longer-term data are needed to clarify the safety and long-term effectiveness of single-incision slings compared to other mid-urethral slings.

Association between antenatal care facility readiness and provision of care at the client level and facility level in five low- and middle-income countries.

BACKGROUND: Despite growing interest in monitoring improvements in quality of care, data on service quality in low-income and middle-income countries (LMICs) is limited. While health systems researchers have hypothesized the relationship between facility readiness and provision of care, there have been few attempts to quantify this relationship in LMICs. This study assesses the association between facility readiness and provision of care for antenatal care at the client level and facility level. METHODS: To assess the association between provision of care and various facility readiness indices for antenatal care, we used multilevel, multivariable random-effects linear regression models. We tested an inflection point on readiness scores by fitting linear spline models. To compare the coefficients between models, we used a bootstrapping approach and calculated the mean difference between all pairwise comparisons. Analyses were conducted at client and facility levels. RESULTS: Our results showed a small, but significant association between facility readiness and provision of care across countries and most index constructions. The association was most evident in the client-level analyses that had a larger sample size and were adjusted for factors at the facility, health worker, and individual levels. In addition, spline models at a facility readiness score of 50 better fit the data, indicating a plausible threshold effect. CONCLUSIONS: The results of this study suggest that facility readiness is not a proxy for provision of care, but that there is an important association between facility readiness and provision of care. Data on facility readiness is necessary for understanding the foundations of health systems particularly in countries with the lowest levels of service quality. However, a comprehensive view of quality of care should include both facility readiness and provision of care measures.

Estimating the health impact of vaccination against ten pathogens in 98 low-income and middle-income countries from 2000 to 2030: a modelling study.

BACKGROUND: The past two decades have seen expansion of childhood vaccination programmes in low-income and middle-income countries (LMICs). We quantify the health impact of these programmes by estimating the deaths and disability-adjusted life-years (DALYs) averted by vaccination against ten pathogens in 98 LMICs between 2000 and 2030. METHODS: 16 independent research groups provided model-based disease burden estimates under a range of vaccination coverage scenarios for ten pathogens: hepatitis B virus, Haemophilus influenzae type B, human papillomavirus, Japanese encephalitis, measles, Neisseria meningitidis serogroup A, Streptococcus pneumoniae, rotavirus, rubella, and yellow fever. Using standardised demographic data and vaccine coverage, the impact of vaccination programmes was determined by comparing model estimates from a no-vaccination counterfactual scenario with those from a reported and projected vaccination scenario. We present deaths and DALYs averted between 2000 and 2030 by calendar year and by annual birth cohort. FINDINGS: We estimate that vaccination of the ten selected pathogens will have averted 69 million (95% credible interval 52-88) deaths between 2000 and 2030, of which 37 million (30-48) were averted between 2000 and 2019. From 2000 to 2019, this represents a 45% (36-58) reduction in deaths compared with the counterfactual scenario of no vaccination. Most of this impact is concentrated in a reduction in mortality among children younger than 5 years (57% reduction [52-66]), most notably from measles. Over the lifetime of birth cohorts born between 2000 and 2030, we predict that 120 million (93-150) deaths will be averted by vaccination, of which 58 million (39-76) are due to measles vaccination and 38 million (25-52) are due to hepatitis B vaccination. We estimate that increases in vaccine coverage and introductions of additional vaccines will result in a 72% (59-81) reduction in lifetime mortality in the 2019 birth cohort. INTERPRETATION: Increases in vaccine coverage and the introduction of new vaccines into LMICs have had a major impact in reducing mortality. These public health gains are predicted to increase in coming decades if progress in increasing coverage is sustained. FUNDING: Gavi, the Vaccine Alliance and the Bill & Melinda Gates Foundation.

Validation of MINORMIX Approach for Estimation of Low Birthweight Prevalence Using a Rural Nepal Dataset.

BACKGROUND: The Global Nutrition Target of reducing low birthweight (LBW) by ≥30% between 2012 and 2025 has led to renewed interest in producing accurate, population-based, national LBW estimates. Low- and middle-income countries rely on household surveys for birthweight data. These data are frequently incomplete and exhibit strong "heaping." Standard survey adjustment methods produce estimates with residual bias. The global database used to report against the LBW Global Nutrition Target adjusts survey data using a new MINORMIX (multiple imputation followed by normal mixture) approach: 1) multiple imputation to address missing birthweights, followed by 2) use of a 2-component normal mixture model to account for heaping of birthweights. OBJECTIVES: To evaluate the performance of the MINORMIX birthweight adjustment approach and alternative methods against gold-standard measured birthweights in rural Nepal. METHODS: As part of a community-randomized trial in rural Nepal, we measured "gold-standard" birthweights at birth and returned 1-24 mo later to collect maternally reported birthweights using standard survey methods. We compared estimates of LBW from maternally reported data derived using: 1) the new MINORMAX approach; 2) the previously used Blanc-Wardlaw adjustment; or 3) no adjustment for missingness or heaping against our gold standard. We also assessed the independent contribution of multiple imputation and curve fitting to LBW adjustment. RESULTS: Our gold standard found 27.7% of newborns were LBW. The unadjusted LBW estimate based on maternal report with simulated missing birthweights was 14.5% (95% CI: 11.6, 18.0%). Application of the Blanc-Wardlaw adjustment increased the LBW estimate to 20.6%. The MINORMIX approach produced an estimate of 26.4% (95% CI: 23.5, 29.3%) LBW, closest to and with bounds encompassing the measured point estimate. CONCLUSIONS: In a rural Nepal validation dataset, the MINORMIX method generated a more accurate LBW estimate than the previously applied adjustment method. This supports the use of the MINORMIX method to produce estimates for tracking the LBW Global Nutrition Target.

First-Principles Insights into Plasmon-Induced Catalysis.

The size- and shape-controlled enhanced optical response of metal nanoparticles (NPs) is referred to as a localized surface plasmon resonance (LSPR). LSPRs result in amplified surface and interparticle electric fields, which then enhance light absorption of the molecules or other materials coupled to the metallic NPs and/or generate hot carriers within the NPs themselves. When mediated by metallic NPs, photocatalysis can take advantage of this unique optical phenomenon. This review highlights the contributions of quantum mechanical modeling in understanding and guiding current attempts to incorporate plasmonic excitations to improve the kinetics of heterogeneously catalyzed reactions. A range of first-principles quantum mechanics techniques has offered insights, from ground-state density functional theory (DFT) to excited-state theories such as multireference correlated wavefunction methods. Here we discuss the advantages and limitations of these methods in the context of accurately capturing plasmonic effects, with accompanying examples.

DFT exchange: sharing perspectives on the workhorse of quantum chemistry and materials science.

In this paper, the history, present status, and future of density-functional theory (DFT) is informally reviewed and discussed by 70 workers in the field, including molecular scientists, materials scientists, method developers and practitioners. The format of the paper is that of a roundtable discussion, in which the participants express and exchange views on DFT in the form of 302 individual contributions, formulated as responses to a preset list of 26 questions. Supported by a bibliography of 777 entries, the paper represents a broad snapshot of DFT, anno 2022.

The effect of sampling health facilities on estimates of effective coverage: a simulation study.

BACKGROUND: Most existing facility assessments collect data on a sample of health facilities. Sampling of health facilities may introduce bias into estimates of effective coverage generated by ecologically linking individuals to health providers based on geographic proximity or administrative catchment. METHODS: We assessed the bias introduced to effective coverage estimates produced through two ecological linking approaches (administrative unit and Euclidean distance) applied to a sample of health facilities. Our analysis linked MICS household survey data on care-seeking for child illness and childbirth care with data on service quality collected from a census of health facilities in the Savanes region of Cote d'Ivoire. To assess the bias introduced by sampling, we drew 20 random samples of three different sample sizes from our census of health facilities. We calculated effective coverage of sick child and childbirth care using both ecological linking methods applied to each sampled facility data set. We compared the sampled effective coverage estimates to ecologically linked census-based estimates and estimates based on true source of care. We performed sensitivity analyses with simulated preferential care-seeking from higher-quality providers and randomly generated provider quality scores. RESULTS: Sampling of health facilities did not significantly bias effective coverage compared to either the ecologically linked estimates derived from a census of facilities or true effective coverage estimates using the original data or simulated random quality sensitivity analysis. However, a few estimates based on sampling in a setting where individuals preferentially sought care from higher-quality providers fell outside of the estimate bounds of true effective coverage. Those cases predominantly occurred using smaller sample sizes and the Euclidean distance linking method. None of the sample-based estimates fell outside the bounds of the ecologically linked census-derived estimates. CONCLUSIONS: Our analyses suggest that current health facility sampling approaches do not significantly bias estimates of effective coverage produced through ecological linking. Choice of ecological linking methods is a greater source of bias from true effective coverage estimates, although facility sampling can exacerbate this bias in certain scenarios. Careful selection of ecological linking methods is essential to minimize the potential effect of both ecological linking and sampling error.

Optimal functionalization of a molecular electrocatalyst for hydride transfer.

Optimization of hydride transfer (HT) catalysts to enhance rates and selectivities of (photo)electroreduction reactions could be a crucial component of a sustainable chemical industry. Here, we analyze how ring functionalization of the adsorbed transient intermediate 2-pyridinide (2-PyH-*)-predicted to form in situ from pyridine (Py) in acidified water at a cathode surface and to be the key to selective CO2 photoelectroreduction on p-GaP-may enhance catalytic activity. Earlier studies revealed that 2-PyH-*'s instability results from a protonation side reaction producing adsorbed dihydropyridine (DHP*), which is relatively HT-inactive. Reducing the electron density on 2-PyH-* could limit this protonation, with the trade-off that it may become less active for HT from 2-PyH-*-R to CO2 We explore here how Py functionalization affects the electron distribution and in turn tunes the catalytic performance of 2-PyH-*. We indeed find that electron-withdrawing groups could enhance the stability of 2-PyH-* by reducing its electron density on the ring. Furthermore, we find that the change in the number of electrons on the substituting group of the hydride donor is a good descriptor for both the stability against protonation and the magnitude of the HT barrier. We predict that -CH2-CH2F is the best candidate substituent, as it significantly improves the stability of 2-PyH-* with only a small increase in HT barrier. -CH=CH2 and -CH2F also could be promising, although they require further investigation due to a larger HT-barrier increase.