During epidemics of cholera in two rural sites (Bakerganj and Mathbaria), a much higher proportion of patients came for treatment with severe dehydration than was seen in previous years. V. cholerae O1 isolated from these patients was found to be El Tor in its phenotype, but its cholera toxin (CT) was determined to be that of classical biotype. Whether the observed higher proportion of severe dehydration produced by the El Tor biotype was due to a shift from El Tor to classical CT or due to other factors is not clear. However, if cholera due to strains with increased severity spread to other areas where treatment facilities are limited, there are likely to be many more cholera deaths.

In this work, we present a general theoretical and numerical approach for simultaneously solving the photovoltage and photocurrent at semiconductor−liquid interfaces. Our methodology extends drift-diffusion methods developed for metal−semiconductor Schottky contacts in the device physics community into the domain of semiconductor− liquid "pseudo-Schottky" contacts. This model is applied to the study of photoelectrochemical anodes, utilized in the oxidative splitting of water. To capture both the photovoltage and photocurrent at semiconductor−liquid interfaces, we show that it is necessary to solve both the electron and hole current continuity equations simultaneously. The electron continuity equation is needed to primarily capture the photovoltage formation at photoanodes, whereas the hole continuity equation must be solved to obtain the photocurrent. Both continuity equations are solved through coupled recombination and generation terms. Moreover, to capture charge transfer at the semiconductor−liquid interface, floating (Neumann) boundary conditions are applied to the electron and hole continuity equations. As a model system, we have studied the illuminated hematite photoanode, where it is shown that our approach can capture band flattening during the formation of a photovoltage, as well as the photocurrent onset and saturation. Finally, the utility of this methodology is demonstrated by correlating our theoretical calculations with photocurrent measurements reported in the literature. In general, this work is intended to expand the scope of photocatalytic device design tools and thereby aid the optimization of solar fuel generation.

Introduction Dietary diversity score (DDS) is a proxy indicator for measuring nutrient adequacy. In this study, we aimed to identify the nutritional statuses and current patterns of DDS among children between 6–59 months old and their associations with different individual and household level factors in rural Bangladesh. Methods The Nobokoli programme of World Vision Bangladesh was implemented in Mymensingh, Sherpur, Rangpur, Dinajpur, Thakurgaon, Panchagar, and Nilphamari districts of Bangladesh between 2014 and 2017. A cross-sectional community household survey was administered between July and October 2014 to collect baseline data to evaluate the Nobokoli programme. A total of 6,468 children between 6–59 months old were included in the final analysis. Anthropometric data was collected following WHO guidelines on using wooden height and digital weight scales. We collected food intake information for the past 24 hours of the survey. The WHO’s child growth standard medians were used to identify the nutritional indices of stunting, wasting, and underweight. Food items consumed were categorized into nine food groups and the DDS was constructed by counting the consumption of food items across these groups during the preceding 24 hour period. The association of DDS and nutritional status (stunting, wasting and underweight) with sociodemographic factors and household food security status were examined using multivariable models; linear regression and logistics regression respectively. Results The prevalence of stunting, wasting and underweight among children aged 6-59months were 36.8%, 18.2% and 37.7% respectively. Our findings revealed that almost all children ate any form of starch followed by consumption of milk or milk products (76%) and fleshy meat /fish (61%) respectively. The mean DDS among children was 3.93(sd 1.47). Forty percent of the children obtained a DDS score less than 4. Multivariable analysis suggested that children whose mothers had higher educational attainment and are skilled workers had higher DDS (15% and 48% respectively) compared to their counterparts. The DDS showed strong positive association with household wealth status. Children from food secure households had 26% higher DDS compared to children from food insecure households. Similarly, increasing maternal education and household wealth were found to be protective against childhood stunting and undernutrition. Discussion Our findings reiterate the need for improving household socioeconomic factors and household food security status for improving dietary diversity practices and nutritional status of children. Evidence-based solutions are needed to be implemented and expanded at scale to ensure appropriate dietary practices and improve nutritional status of the children in local context.

Abstract

IntroductionSepsis is dysregulated systemic inflammatory response which can lead to tissue damage, organ failure, and death. With an estimated 30 million cases per year, it is a global public health concern. Severe infections leading to sepsis account for more than half of all under five deaths and around one quarter of all neonatal deaths annually. Most of these deaths occur in low and middle income countries and could be averted by rapid assessment and appropriate treatment. Evidence suggests that service provision and quality of care pertaining to sepsis management in resource poor settings can be improved significantly with minimum resource allocation and investments. Cognizant of the stark realities, a project titled ‘Interrupting Pathways to Sepsis Initiative’ (IPSI) introduced a package of interventions for improving quality of care pertaining to sepsis management at 2 sub-district level public hospitals in rural Bangladesh. We present here the quality improvement process and achievements regarding some fundamental steps of sepsis management which include rapid identification and admission, followed by assessment for hypoxemia, hypoglycaemia and hypothermia, immediate resuscitation when required and early administration of parenteral broad spectrum antibiotics.Materials and MethodKey components of the intervention package include identification of structural and functional gaps through a baseline environmental scan, capacity development on protocolized management through training and supportive supervision by onsite ‘Program Coaches’, facilitating triage and rapid transfer of patients through ‘Welcoming Persons’ and enabling rapid treatment through ‘Task Shifting’ from on-call physicians to on-duty paramedics in the emergency department and on-call physicians to on-duty nurses in the inpatient department.ResultsFrom August, 2013 to March, 2015, 1,262 under-5 children were identified as syndromic sepsis in the emergency departments; of which 82% were admitted. More neonates (30%) were referred to higher level facilities than post-neonates (6%) (p<0.05). Immediately after admission, around 99% were assessed for hypoxemia, hypoglycaemia and hypothermia. Around 21% were hypoxemic (neonate-37%, post-neonate-18%, p<0.05), among which 94% received immediate oxygenation. Vascular access was established in 78% cases and 85% received recommended broad spectrum antibiotics parenterally within 1 hour of admission. There was significant improvement in the rate of establishing vascular access and choice of recommended first line parenteral antibiotic over time. After arrival in the emergency department, the median time taken for identification of syndromic sepsis and completion of admission procedure was 6 minutes. The median time taken for completion of assessment for complications was 15 minutes and administration of first dose of broad spectrum antibiotics was 35 minutes. There were only 3 inpatient deaths during the reporting period.Discussion and ConclusionNeeds based health systems strengthening, supportive-superv...

In this work we present a theoretical connection between the Landauer picture utilized in quantum transport and the Gerischer picture utilized in electrochemistry. A comprehensive analysis of the single-particle picture and total energy picture in electrochemistry is presented, followed by derivation of electron transfer rates utilizing the nonequilibrium Green's function formalism. Correlations are also made with the Marcus−Hush theoretical approach more often utilized in electrochemistry. The analysis is limited to tunneling (also called outer-sphere) electrochemical reactions. In general, it is expected that this work will serve to further bridge the diverse condensed matter and chemistry foundations inherent to interfacial electrochemistry.

In this work, we present a theoretical study of surface state occupation statistics at semiconductor-liquid interfaces, as it pertains to the evolution of H and O through water splitting. Our approach combines semiclassical charge transport and electrostatics at the semiconductor-liquid junction, with a master rate equation describing surface state mediated electron/hole transfer. As a model system we have studied the TiO-water junction in the absence of illumination, where it is shown that surface states might not always equilibrate with the semiconductor. Non-trivial electrostatics, for example including a shifting of the Mott-Schottky plateau in capacitive measurements, are explored when deep-level surface states partially equilibrate with the liquid. We also endeavor to explain observations of non-linearity present in Mott-Schottky plots, as they pertain to surface state occupation statistics. In general, it is intended that the results of this work will serve to further the use and development of quantitative device modeling techniques in the description of H evolution at semiconductor-liquid junctions.

Recent studies have demonstrated the high efficiency through which nanostructured core-shell WO 3 /TiO 2 (WT) heterojunctions can photocatalytically degrade model organic pollutants (stearic acid, QE ∼ 18% @ λ = 365 nm), and as such, has varied potential environmental and antimicrobial applications. The key motivation herein is to connect theoretical calculations of charge transport phenomena, with experimental measures of charge carrier behaviour using transient absorption spectroscopy (TAS), to develop a fundamental understanding of how such WT heterojunctions achieve high photocatalytic efficiency (in comparison to standalone WO 3 and TiO 2 photocatalysts). This work reveals an order of magnitude enhancement in electron and hole recombination lifetimes, respectively located in the TiO 2 and WO 3 sides, when an optimally designed WT heterojunction photocatalyst operates under UV excitation. This observation is further supported by our computationally captured details of conduction band and valence band processes, identified as: (i) dominant electron transfer from WO 3 to TiO 2 via the diffusion of excess electrons; and (ii) dominant hole transfer from TiO 2 to WO 3 via thermionic emission over the valence band edge. Simultaneously, our combined theoretical and experimental study offers a time-resolved understanding of what occurs on the micro-to milli-seconds (µs-ms) timescale in this archetypical photocatalytic heterojunction. At the microsecond timescale, a portion of the accumulated holes in WO 3 contribute to the depopulation of W 5+ polaronic states, while remaining accumulated holes in WO 3 are separated from adjacent electrons in TiO 2 up to 3 ms after photoexcitation. The presence of these exceptionally long-lived photogenerated carriers, dynamically separated by the WT heterojunction, is the origin of the superior photocatalytic efficiency displayed by this system (in the degradation of stearic acid). Consequently, our combined computational and experimental approach delivers a robust understanding of the direction of charge separation along with critical time-resolved insights into the evolution of charge transport phenomena in this model heterojunction photocatalyst.