28 research outputs found
EHD-driven mass transport enhancement in surface dielectric barrier discharges
Surface Dielectric Barrier Discharges (S-DBDs) have received renewed attention in recent years for their
potential application in emerging biomedical, environmental and agricultural applications. In most of these
applications, the plasma is not in direct contact with the substrate being treated and the transport of reactive species
from the plasma to the substrate is typically assumed to be controlled by diffusion. Here, we demonstrate that
generally this is not the case and that electrohydrodynamic (EHD) forces can produce jets that enhance the delivery
of these species, thereby influencing the efficacy of the S-DBD device. In particular, we have studied the
degradation of potassium indigotrisulfonate solutions exposed to S-DBDs generated in devices with annular
electrodes of diameters varying between 10mm and 50mm. All the devices were driven at constant linear power
density (Watts per cm of plasma length) and although local plasma properties remained the same in all the devices, a
three-fold efficacy enhancement was observed for devices of diameter ~30mm due to EHD effects
Treatment outcomes and associated factors for hospitalization of children treated for acute malnutrition under the OptiMA simplified protocol: a prospective observational cohort in rural Niger
IntroductionGlobally, access to treatment for severe and moderate acute malnutrition is very low, in part because different protocols and products are used in separate programs. New approaches, defining acute malnutrition (AM) as mid-upper arm circumference (MUAC) < 125 mm or oedema, are being investigated to compare effectiveness to current programs. Optimizing Malnutrition treatment (OptiMA) is one such strategy that treats AM with one product – ready-to-use therapeutic food, or RUTF – at reduced dosage as the child improves.MethodsThis study aimed to determine whether OptiMA achieved effectiveness benchmarks established in the Nigerien National Nutrition protocol. A prospective cohort study of children in the rural Mirriah district evaluated outcomes among children 6-59 months with uncomplicated AM treated under OptiMA. In a parallel, unconnected program in one of the two trial sites, all non-malnourished children 6-23 months of age were provided small quantity lipid-based nutritional supplements (SQ-LNS). A multivariate logistic regression identified factors associated with hospitalization.ResultsFrom July-December 2019, 1,105 children were included for analysis. Prior to treatment, 39.3% of children received SQ-LNS. Recovery, non-response, and mortality rates were 82.3%, 12.6%, and 0.7%, respectively, and the hospitalization rate was 15.1%. Children who received SQ-LNS before an episode of AM were 43% less likely to be hospitalized (ORa=0.57; 0.39-0.85, p = 0.004).DiscussionOptiMA had acceptable recovery compared to the Nigerien reference but non-response was high. Children who received SQ-LNS before treatment under OptiMA were less likely to be hospitalized, showing potential health benefits of combining simplified treatment protocols with food-based prevention in an area with a high burden of malnutrition such as rural Niger
Lassa fever outcomes and prognostic factors in Nigeria (LASCOPE): a prospective cohort study
BACKGROUND: Lassa fever is a viral haemorrhagic fever endemic in parts of west Africa. New treatments are needed to decrease mortality, but pretrial reference data on the disease characteristics are scarce. We aimed to document baseline characteristics and outcomes for patients hospitalised with Lassa fever in Nigeria. METHODS: We did a prospective cohort study (LASCOPE) at the Federal Medical Centre in Owo, Nigeria. All patients admitted with confirmed Lassa fever were invited to participate and asked to give informed consent. Patients of all ages, including newborn infants, were eligible for inclusion, as were pregnant women. All participants received standard supportive care and intravenous ribavirin according to Nigeria Centre for Disease Control guidelines and underwent systematic biological monitoring for 30 days. Patients' characteristics, care received, mortality, and associated factors were recorded using standard WHO forms. We used univariable and multivariable logistic regression models to investigate an association between baseline characteristics and mortality at day 30. FINDINGS: Between April 5, 2018, and March 15, 2020, 534 patients with confirmed Lassa fever were admitted to hospital, of whom 510 (96%) gave consent and were included in the analysis. The cohort included 258 (51%) male patients, 252 (49%) female patients, 426 (84%) adults, and 84 (16%) children (younger than 18 years). The median time between first symptoms and hospital admission was 8 days (IQR 7-13). At baseline, 176 (38%) of 466 patients had a Lassa fever RT-PCR cycle threshold (Ct) lower than 30. From admission to end of follow-up, 120 (25%) of 484 reached a National Early Warning Score (second version; NEWS2) of 7 or higher, 67 (14%) of 495 reached a Kidney Disease-Improving Global Outcome (KDIGO) stage of 2 or higher, and 41 (8%) of 510 underwent dialysis. All patients received ribavirin for a median of 10 days (IQR 9-13). 62 (12%) patients died (57 [13%] adults and five [6%] children). The median time to death was 3 days (1-6). The baseline factors independently associated with mortality were the following: age 45 years or older (adjusted odds ratio 16·30, 95% CI 5·31-50·30), NEWS2 of 7 or higher (4·79, 1·75-13·10), KDIGO grade 2 or higher (7·52, 2·66-21·20), plasma alanine aminotransferase 3 or more times the upper limit of normal (4·96, 1·69-14·60), and Lassa fever RT-PCR Ct value lower than 30 (4·65, 1·50-14·50). INTERPRETATION: Our findings comprehensively document clinical and biological characteristics of patients with Lassa fever and their relationship with mortality, providing prospective estimates that could be useful for designing future therapeutic trials. Such trials comparing new Lassa fever treatments to a standard of care should take no more than 15% as the reference mortality rate and consider adopting a combination of mortality and need for dialysis as the primary endpoint. FUNDING: Institut National de la Santé et de la Recherche Médicale, University of Oxford, EU, UK Department for International Development, Wellcome Trust, French Ministry of Foreign Affairs, Agence Nationale de Recherches sur le SIDA et les hépatites virales, French National Research Institute for Sustainable Development
Examining the generalizability of research findings from archival data
This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability—for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples
Creative destruction in science
Drawing on the concept of a gale of creative destruction in a capitalistic economy, we argue that initiatives to assess the robustness of findings in the organizational literature should aim to simultaneously test competing ideas operating in the same theoretical space. In other words, replication efforts should seek not just to support or question the original findings, but also to replace them with revised, stronger theories with greater explanatory power. Achieving this will typically require adding new measures, conditions, and subject populations to research designs, in order to carry out conceptual tests of multiple theories in addition to directly replicating the original findings. To illustrate the value of the creative destruction approach for theory pruning in organizational scholarship, we describe recent replication initiatives re-examining culture and work morality, working parents\u2019 reasoning about day care options, and gender discrimination in hiring decisions.
Significance statement
It is becoming increasingly clear that many, if not most, published research findings across scientific fields are not readily replicable when the same method is repeated. Although extremely valuable, failed replications risk leaving a theoretical void\u2014 reducing confidence the original theoretical prediction is true, but not replacing it with positive evidence in favor of an alternative theory. We introduce the creative destruction approach to replication, which combines theory pruning methods from the field of management with emerging best practices from the open science movement, with the aim of making replications as generative as possible. In effect, we advocate for a Replication 2.0 movement in which the goal shifts from checking on the reliability of past findings to actively engaging in competitive theory testing and theory building.
Scientific transparency statement
The materials, code, and data for this article are posted publicly on the Open Science Framework, with links provided in the article
Examining the generalizability of research findings from archival data
This initiative examined systematically the extent to which a large set of archival research findings generalizes across contexts. We repeated the key analyses for 29 original strategic management effects in the same context (direct reproduction) as well as in 52 novel time periods and geographies; 45% of the reproductions returned results matching the original reports together with 55% of tests in different spans of years and 40% of tests in novel geographies. Some original findings were associated with multiple new tests. Reproducibility was the best predictor of generalizability-for the findings that proved directly reproducible, 84% emerged in other available time periods and 57% emerged in other geographies. Overall, only limited empirical evidence emerged for context sensitivity. In a forecasting survey, independent scientists were able to anticipate which effects would find support in tests in new samples
Recycled or Bio-Based Solvents for the Synthesis of ZnO Nanoparticles: Characterization and Validation in Organic Solar Cells
Among solution-processable metal oxides, zinc oxide (ZnO) nanoparticle inks are widely used in inverted organic solar cells for the preparation, at relatively low temperatures (r-MeOH) to close the loop and minimize wastes or (ii) bioethanol (b-EtOH) to prove the effectiveness of a bio-based solvent. The effect of r-MeOH and b-EtOH on the optical, morphological, and electronic properties of the resulting ZnO NPs, both in solution and thin-films, is investigated, discussed, and compared to an analogous reference material. Moreover, to validate the properties of the resulting materials, we have prepared PTB7:PC71BM-based solar cells containing the different ZnO NPs as a cathode interlayer. Power conversion efficiencies comparable to the reference system (≈7%) were obtained, validating the proposed alternative and more sustainable approach