959 research outputs found
A Computational Study of UV disinfection performance within a naturally ventilated hospital ward
The airborne transmission of pathogens including tuberculosis and influenza pose a significant threat to human health. This is especially the case in healthcare settings such as hospital wards which inevitably contain a high concentration of viruses and bacteria. These have the potential to infect both patients with weakened immune systems and healthcare workers. In order to reduce the infection risk, improvements in hospital ward design and the application of disinfection systems can offer significant benefits. One such strategy, upper-room Ultraviolet Germicidal Irradiation (UVGI), relies on a collimated irradiance field which works in conjunction with ventilation patterns to disinfect the air. The focus of this study is to predict the UVGI system performance within a naturally ventilated hospital ward, for a range of ambient conditions using Computational Fluid Dynamics (CFD). A computer model of an open-plan six-bed Nightingale-style hospital ward was generated based on the dimensions of a former hospital building situated in Bradford, UK. With a total volume of 200 m3, natural ventilation is supplied through three casement windows and a further three openings on the leeward side ensure steady cross-ventilation. Boundary conditions are based on experimental measurements of the ventilation rate which were determined using a tracer technique. An experimentally-determined irradiance field is included in the model and stored as a fixed-value scalar field. A total of fifty steady-state CFD simulations show that disinfection performance depends on the ventilation rate, the degree of mixing present and the position of the UVGI fixture within the ward. The results underline the potential performance gains from UVGI installations and how they could be integrated within existing healthcare facilities as an infection control measure
Small scale integrated agriculture: a tool of poverty alleviation, gender equality promotion and improving food security at household level in coastal region of Bangladesh
The chemical composition of four edible plant foods species, three fish species and one prawn were analyzed in Food Chemistry Laboratory of Behbahan Khatam Alanbia University of Technology, Behbahan, Iran in 2014. The analysis of fatty acid and sugars composition were performed by gas liquid chromatography and high performance liquid chromatography, respectively. Protein and lipid content were founded higher in baked and fried in fish S. commersonnianus (74.29%), (20.20%), fish Sphyraena helleri (88.12%) and (17.77%), respectively. Ash content in fish S. commersonnianus varies from 9.80% to 15.34%, and in fish S. helleri from 5.83% to 7.68%. Based on the proximate analysis, it can be calculated that an edible portion of 100 g of studied edible plant foods provides, on average, around 303.9±1.04 kcal. The plant Portulaca neglecta is suitable for high temperature food processes. The macronutrient profile in general revealed that the wild plant foods were with rich sources of protein and carbohydrates, and had low amounts of fat. The highest protein, the lowest fat and energy contents were found in boiled in both fish species; therefore, boiling can be recommended as the best cooking method for healthy diet.Int. J. Agril. Res. Innov. & Tech. 5 (2): 82-85, December, 201
Simulating Pathogen Transport within a Naturally Ventilated Hospital Ward
Understanding how airborne pathogens are transported through hospital wards is essential for determining the infection risk to patients and healthcare workers. This study utilizes Computational Fluid Dynamics (CFD) simulations to explore pathogen transport within a six-bed Nightingale hospital ward. Grid independence of a ward model was addressed using the Grid Convergence Index (GCI) from solutions obtained using three fully-structured grids. Pathogens were simulated using source terms in conjunction with a scalar transport equation and a RANS turbulence model. Errors were found to be less than 4% in the prediction of air velocities but an average of 13% was seen in the scalar field. A parametric study into the pathogen release point illustrated that its distribution is strongly influenced by the local velocity field and the degree of mixing present
Development of a numerical optimization approach to ventilation system design to control airborne contaminant dispersion and occupant comfort
Airflow, contaminant and temperature during heating and ventilation in a model room represented by a square cavity with inlet and outlet ports, has been studied. The aim of this work is concerned with the development and implementation of a practical and robust optimization scheme based on the combination of Genetic algorithm and response surface methodology (RSM) with the aim of assisting hospital ward designers and managers /operators to enhance infection control (i.e. reduce the risk of airborne transmission) without compromising patient comfort and environmental impact
LBM-MHD Data-Driven Approach to Predict Rayleigh–Bénard Convective Heat Transfer by Levenberg–Marquardt Algorithm
This study aims to consider lattice Boltzmann method (LBM)–magnetohydrodynamics (MHD) data to develop equations to predict the average rate of heat transfer quantitatively. The present approach considers a 2D rectangular cavity with adiabatic side walls, and the bottom wall is heated while the top wall is kept cold. Rayleigh–Bénard (RB) convection was considered a heat-transfer phenomenon within the cavity. The Hartmann (Ha) number, by varying the inclination angle (θ), was considered in developing the equations by considering the input parameters, namely, the Rayleigh (Ra) numbers, Darcy (Da) numbers, and porosity (ϵ) of the cavity in different segments. Each segment considers a data-driven approach to calibrate the Levenberg–Marquardt (LM) algorithm, which is highly linked with the artificial neural network (ANN) machine learning method. Separate validations have been conducted in corresponding sections to showcase the accuracy of the equations. Overall, coefficients of determination (R2) were found to be within 0.85 to 0.99. The significant findings of this study present mathematical equations to predict the average Nusselt number (Nu¯). The equations can be used to quantitatively predict the heat transfer without directly simulating LBM. In other words, the equations can be considered validations methods for any LBM-MHD model, which considers RB convection within the range of the parameters in each equation
Antibody-Mediated LILRB2-Receptor Antagonism Induces Human Myeloid-Derived Suppressor Cells to Kill Mycobacterium tuberculosis
Tuberculosis is a leading cause of death in mankind due to infectious agents, and Mycobacterium tuberculosis (Mtb) infects and survives in macrophages (MФs). Although MФs are a major niche, myeloid-derived suppressor cells (MDSCs) are an alternative site for pathogen persistence. Both MФs and MDSCs express varying levels of leukocyte immunoglobulin-like receptor B (LILRB), which regulate the myeloid cell suppressive function. Herein, we demonstrate that antagonism of LILRB2 by a monoclonal antibody (mab) induced a switch of human MDSCs towards an M1-macrophage phenotype, increasing the killing of intracellular Mtb. Mab-mediated antagonism of LILRB2 alone and its combination with a pharmacological blockade of SHP1/2 phosphatase increased proinflammatory cytokine responses and phosphorylation of ERK1/2, p38 MAPK, and NF-kB in Mtb-infected MDSCs. LILRB2 antagonism also upregulated anti-mycobacterial iNOS gene expression and an increase in both nitric oxide and reactive oxygen species synthesis. Because genes associated with the anti-mycobacterial function of M1-MФs were enhanced in MDSCs following mab treatment, we propose that LILRB2 antagonism reprograms MDSCs from an immunosuppressive state towards a pro-inflammatory phenotype that kills Mtb. LILRB2 is therefore a novel therapeutic target for eradicating Mtb in MDSCs
N-{3-[Bis(2-hydroxyethyl)aminomethyl]-5-nitrophenyl}benzamide
The title compound, C18H21N3O5, was prepared by the reaction of 3-benzamido-5-nitrobenzyl methanesulfonate with diethanolamine and is an intermediate in the synthesis of DNA minor-groove-binding polybenzamide agents capable of being conjugated to additional biologically active species. The asymmetric unit contains two independent molecules, which differ only in the orientations of the hydroxyethyl groups. In the crystal structure, intermolecular N—H⋯O and O—H⋯O hydrogen bonds link molecules into one-dimensional chains
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