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1.
Kidney International Reports ; 7(9):S463, 2022.
Article in English | EMBASE | ID: covidwho-2041679

ABSTRACT

Introduction: The COVID-19 pandemic has highlighted the need to address how renal insults are treated. There is an urgent need to better understand the complex relationship between infections and kidney disease and develop safe and effective approaches that can be translated to the clinic. Hydrodynamic fluid delivery has shown promise in influencing renal function in disease models. This technique previously provided preconditioned protection in acute injury models by upregulating the mitochondrial adaptation, while hydrodynamic injections of saline alone have also improved microvascular perfusion. Accordingly, hydrodynamic mitochondrial gene delivery was applied to investigate its ability to halt renal impairment that may occur following episodes of acute moderate and severe injuries in a rat model. Methods: Transgene infusates were prepared by suspending approximately 2 μg of IDH2 (isocitrate dehydrogenase 2 (NADP+) and mitochondrial) plasmid DNA/g of body weight in 0.5 ml of saline. Animals were subjected to moderate (bilateral pedicle clamp 30 mins) or severe (bilateral pedicle clamp 60 mins) forms of ischemia-reperfusion injury (IRI). Infusates were delivered directly into the left renal vein within 5 seconds, roughly 1 hour after IRI was established. Serum creatinine (SCr) and blood urea nitrogen (BUN) levels were monitored for 2 weeks. Results: Significant reductions in the levels of both metabolites (p < 0.05 for both cases) were achieved with single transgene treatments administered at both time points. Specifically, the maximal rises in SCr and BUN levels were reduced by at least 50%, which translated the effects of a severe injury to a moderate injury and a moderate injury to a mild injury. Conclusions: Therefore, this study identifies an approach that boosts recovery and halts the progression of ischemia-reperfusion at its inception and can be vital for high-risk conditions and may help devise translation models to address the rising incidence of acute renal diseases. No conflict of interest

2.
International Journal of Numerical Methods for Heat & Fluid Flow ; 32(9):2964-2981, 2022.
Article in English | ProQuest Central | ID: covidwho-1948670

ABSTRACT

Purpose>The purpose of this paper is to devise a tool based on computational fluid dynamics (CFD) and machine learning (ML), for the assessment of potential airborne microbial transmission in enclosed spaces. A gated recurrent units neural network (GRU-NN) is presented to learn and predict the behaviour of droplets expelled through breaths via particle tracking data sets.Design/methodology/approach>A computational methodology is used for investigating how infectious particles that originated in one location are transported by air and spread throughout a room. High-fidelity prediction of indoor airflow is obtained by means of an in-house parallel CFD solver, which uses a one equation Spalart–Allmaras turbulence model. Several flow scenarios are considered by varying different ventilation conditions and source locations. The CFD model is used for computing the trajectories of the particles emitted by human breath. The numerical results are used for the ML training.Findings>In this work, it is shown that the developed ML model, based on the GRU-NN, can accurately predict the airborne particle movement across an indoor environment for different vent operation conditions and source locations. The numerical results in this paper prove that the presented methodology is able to provide accurate predictions of the time evolution of particle distribution at different locations of the enclosed space.Originality/value>This study paves the way for the development of efficient and reliable tools for predicting virus airborne movement under different ventilation conditions and different human positions within an indoor environment, potentially leading to the new design. A parametric study is carried out to evaluate the impact of system settings on time variation particles emitted by human breath within the space considered.

3.
Pharmaceutical Technology ; 45(11):34-40, 2021.
Article in English | EMBASE | ID: covidwho-1935337
4.
European Journal of Hospital Pharmacy ; 29(SUPPL 1):A23-A24, 2022.
Article in English | EMBASE | ID: covidwho-1916404

ABSTRACT

Background and importance The importance of mRNA-based vaccines increased rapidly due to the COVID-19 pandemic. However, little is known on the challenges linked to handling shortages and extended stability of these new types of substance. Since vaccine remnants have to be discarded according to the Summary of Product Characteristics, we hypothesise that sterile filtration after pooling is suitable to save vaccine material for clinical application. Aim and objectives The aim of this pilot study was to compare quality parameters of remnants derived from ready-to-use mRNA vaccine solutions before and after sterile filtration. Therefore, we pooled mRNA vaccine solution remnants from Corminaty vials (BioNTech/Pfizer) and compared particle size, distribution and quantity of the lipoplexes. In addition, quantity and/or quality of the mRNA was determined. Material and methods Measurements of invisible particulates in the range 1-50 mm were performed by light obscuration according to the European Pharmacopoeia (10th edn). The size of lipoplexes was measured with nanoparticle tracking analysis (NTA) to determine hydrodynamic diameter and particle concentration. Dynamic light scattering was employed complementarily to the NTA technique to focus on particle size from 0.3 nm to 10 mm. The concentration, purity and integrity of the mRNA was analysed by ultraviolet (UV) spectrophotometry and capillary electrophoresis after mRNA purification. Results After pooling the remnants of the vials we found a substantial increase of particulates >1 mm when compared to fresh vaccine samples. This effect was likely due to contamination of the examined probes with particles from ambient air. As expected, all these particulates were eliminated by sterile filtration. Size distribution and concentration of the lipoplexes were comparable between unfiltered and filtered samples. With respect to the mRNA, we identified the fragment of interest in all examined samples. Sterile filtration did not change the concentration, purity and integrity of the mRNA. Conclusion and relevance Our results indicate that sterile filtration of mRNA-based vaccines eliminates particle contamination from the vaccine solution while the concentration of lipoplex nanoparticles was not altered. Moreover, neither the quantity nor quality of the mRNA was affected by the filtration process. The results of our pilot study provide the first data on the stability of mRNA vaccines and help to fill knowledge gap when dealing with these substances in hospital pharmacy.

5.
Sustainability ; 14(10):6095, 2022.
Article in English | ProQuest Central | ID: covidwho-1875754

ABSTRACT

Detailed hydrogen–air chemical reaction mechanisms were coupled with the three-dimensional grids of an experimental hydrogen internal combustion engine (HICE) to establish a computational fluid dynamics (CFD) combustion model based on the CONVN1 -https://media.proquest.com/media/hms/PFT/1/iyX6N?_a=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%3D%3D&_s=XxDsfbWeNCPMojxxWroCr%2FH0Al4%3D ERGE software. The effects of different combustion modes on the combustion and emission characteristics of HICE under low load were studied. The simulation results showed that, with the increase in excess hydrogen, the equivalent combustion and excessive hydrogen combustion modes with medium-cooled exhaust gas recirculation (EGR) dilution could improve the intensity of the in-cylinder combustion of HICE, increase the peak values of pressure and temperature in the cylinder, and then improve the indicated thermal efficiency of HICE under low load. However, larger excessive hydrogen combustion could weaken the improvement in performance;therefore, the performance of HICE could be comprehensively improved by the adoption of excessive hydrogen combustion with a fuel–air ratio below 1.2 under low load. The obtained conclusions indicate the research disadvantages in the power and emission performances of HICE under low load, and they are of great significance for the performance optimization of HICE. Furthermore, a control strategy was proposed to improve the stability of HICE under low load.

6.
Journal of Fluid Mechanics ; 942, 2022.
Article in English | ProQuest Central | ID: covidwho-1849581

ABSTRACT

Violent respiratory events play critical roles in the transmission of respiratory diseases, such as coughing and sneezing, between infectious and susceptible individuals. In this work, large-scale multiphase flow large-eddy simulations have been performed to simulate the coughing jet from a human's mouth carrying pathogenic or virus-laden droplets by using a weakly compressible smoothed particle hydrodynamics method. We explicitly model the cough jet ejected from a human mouth in the form of a mixture of two-phase fluids based on the cough velocity profile of the exhalation flow obtained from experimental data and the statistics of the droplets’ sizes. The coupling and interaction between the two expiratory phases and ambient surrounding air are examined based on the interaction between the gas particles and droplet particles. First, the results reveal that the turbulence of the cough jet determines the dispersion of the virus-laden droplets, i.e. whether they fly up evolving into aerosols or fall down to the ground. Second, the droplet particles have significant effects on the evolution of the cough jet turbulence;for example, they increase the complexity and butterfly effect introduced by the turbulence disturbance. Our results show that the prediction of the spreading distance of droplet particles often goes beyond the social distancing rules recommended by the World Health Organization, which reminds us of the risks of exposure if we do not take any protecting protocol.

7.
Applied Sciences ; 12(9):4538, 2022.
Article in English | ProQuest Central | ID: covidwho-1837865

ABSTRACT

Airborne pollutant transport in an aircraft cabin is greatly affected by the created airflow. The seat layout can impact the flow and thus the pollutant transport. Most studies have adopted symmetric upright seats for simplicity. The influence of seat inclination and seat misalignment on airflow and pollutant transport is still unclear. This investigation adopted a validated computational fluid dynamics (CFD) method to study the airflow and airborne pollutant distribution in a single-aisle cabin with seven rows of seats. The pollutant was assumed to be released from a passenger seated in the middle of three adjacent seats. A total of five different seat layouts were considered, including all of the upright seats, the inclination of three adjacent seats, the inclination of all of the seats in half a cabin, the inclination of all of the seats in a whole cabin, and the misalignment seat rows across the aisle. The flows in both the cross and longitudinal sections were compared. The pollutant concentrations in the respiratory zone of the passengers in different seats were adopted to evaluate the cross-contamination. The results revealed that the symmetric seat layout aids to circumscribe the released pollutant in a small region and reduces the cross-contamination either by maintaining the upright seats or inclining all of the seats. Contrarily, any inclination of seats or a misalignment of seat rows should be avoided during the pandemic since an asymmetric seat layout would generate asymmetric flow and strengthen the spreading of pollutants.

8.
ACM Transactions on Parallel Computing ; 9(1), 2022.
Article in English | Scopus | ID: covidwho-1789035

ABSTRACT

The Radial Basis Function (RBF) technique is an interpolation method that produces high-quality unstructured adaptive meshes. However, the RBF-based boundary problem necessitates solving a large dense linear system with cubic arithmetic complexity that is computationally expensive and prohibitive in terms of memory footprint. In this article, we accelerate the computations of 3D unstructured mesh deformation based on RBF interpolations by exploiting the rank structured property of the matrix operator. The main idea consists in approximating the matrix off-diagonal tiles up to an application-dependent accuracy threshold. We highlight the robustness of our multiscale solver by assessing its numerical accuracy using realistic 3D geometries. In particular, we model the 3D mesh deformation on a population of the novel coronaviruses. We report and compare performance results on various parallel systems against existing state-of-the-art matrix solvers. © 2022 Association for Computing Machinery.

9.
Energies ; 15(7):2559, 2022.
Article in English | ProQuest Central | ID: covidwho-1785586

ABSTRACT

Microwave-driven plasma gasification technology has the potential to produce clean energy from municipal and industrial solid wastes. It can generate temperatures above 2000 K (as high as 30,000 K) in a reactor, leading to complete combustion and reduction of toxic byproducts. Characterizing complex processes inside such a system is however challenging. In previous studies, simulations using computational fluid dynamics (CFD) produced reproducible results, but the simulations are tedious and involve assumptions. In this study, we propose machine-learning models that can be used in tandem with CFD, to accelerate high-fidelity fluid simulation, improve turbulence modeling, and enhance reduced-order models. A two-dimensional microwave-driven plasma gasification reactor was developed in ANSYS (Ansys, Canonsburg, PA, USA) Fluent (a CFD tool), to create 644 (geometry and temperature) datasets for training six machine-learning (ML) models. When fed with just geometry datasets, these ML models were able to predict the proportion of the reactor area with temperature above 2000 K. This temperature level is considered a benchmark to prevent formation of undesirable byproducts. The ML model that achieved highest prediction accuracy was the feed forward neural network;the mean absolute error was 0.011. This novel machine-learning model can enable future optimization of experimental microwave plasma gasification systems for application in waste-to-energy.

10.
Water ; 14(3):412, 2022.
Article in English | ProQuest Central | ID: covidwho-1687079

ABSTRACT

This study utilized MIKE 11 to quantify the spatio-temporal dynamics of water quality parameters (Biochemical Oxygen Demand (BOD5), Dissolved Oxygen (DO) and temperature) in the Long Xuyen Quadrangle area of the Vietnamese Mekong Delta. Calibrated for the year of 2019 and validated for the year of 2020, the developed model showed a significant agreement between the observed and simulated values of water quality parameters. Locations near to cage culture areas exhibited higher BOD5 values than sites close to pond/lagoon culture areas due to the effects of numerous point sources of pollution, including upstream wastewater and out-fluxes from residential and tourism activities in the surrounding areas, all of which had a direct impact on the quality of the surface water used for aquaculture. Moreover, as aquacultural effluents have intensified and dispersed over time, water quality in the surrounding water bodies has degraded. The findings suggest that the effective planning, assessment and management of rapidly expanding aquaculture sites should be improved, including more rigorous water quality monitoring, to ensure the long-term sustainable expansion and development of the aquacultural sector in the Long Xuyen Quadrangle in particular, and the Vietnamese Mekong Delta as a whole.

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