Simulated Conditions Research Articles

Photoacoustic/ultrasound dual-modal imaging of human nails: A pilot study

Traditional diagnostic techniques including visual examination, ultrasound (US), and magnetic resonance imaging (MRI) have limitations of in-depth information for the detection of nail disorders, resolution, and practicality. This pilot study, for the first time, evaluates a dual-modality imaging system that combines photoacoustic tomography (PAT) with the US for the multiparametric quantitative assessment of human nail. The study involved a small cohort of five healthy volunteers who underwent PAT/US imaging for acquiring the nail unit data. The PAT/US dual-modality imaging successfully revealed the fine anatomical structures and microvascular distribution within the nail and nail bed. Moreover, this system utilized multispectral PAT to analyze functional tissue parameters, including oxygenated hemoglobin, deoxyhemoglobin, oxygen saturation, and collagen under tourniquet and cold stimulus tests to evaluate changes in the microcirculation of the nail bed. The quantitative analysis of multispectral PAT reconstructed images demonstrated heightened sensitivity in detecting alterations in blood oxygenation levels and collagen content within the nail bed, under simulated different physiological conditions. This pilot study highlights the potential of PAT/US dual-modality imaging as a real-time, noninvasive diagnostic modality for evaluating human nail health and for early detection of nail bed pathologies.

In Vitro Probiotic Characterization of Lactiplantibacillus plantarum Strains Isolated from Traditional Fermented Dockounou Paste

This study aimed to evaluate the probiotic properties of 10 lactic acid bacteria (LAB) isolated from artisanal fermented plantain dockounou paste. A preliminary characterization of the LAB isolates was performed based on phenotypic and several biochemical properties, which was subsequently confirmed through 16S rRNA gene sequencing analysis, indicating that these isolates belonged to the species Lactiplantibacillus plantarum. With regard to safety criteria, the strains exhibited no alpha or beta hemolysis activity. Nevertheless, the majority of LAB strains demonstrated high sensitivity to the antibiotics tested. The results demonstrated that the majority of the strains exhibited remarkably high survival rates under simulated gastrointestinal conditions, such as pH = 1.5 (81.18–98.15%), 0.3% bile salts (68.62–100.89%), 0.4% phenol (40.59–128.24%), as well as 0.1% pepsin and pH = 2.5 (88.54–99.78%). The LAB strains demonstrated elevated levels of cell surface properties, indicative of the presence of a considerable defensive mechanism against pathogens. Intact LAB cells exhibited significant antioxidant abilities (48.18–83.58%). They also demonstrated a pronounced inhibitory effect on the growth of foodborne pathogens. Enzyme pattern analysis revealed that the LAB isolates produced both proteases and cellulases, as well as pectinase and/or amylase activity. The potential of the L. plantarum strains FS43, FS44, and FS48, as indicated by the results obtained from the standard in vitro assays, makes them suitable for further study as potential probiotics.

Antiepileptic drug-loaded and multifunctional iron oxide@silica@gelatin nanoparticles for acid-triggered drug delivery

The current study developed an innovative design for the production of smart multifunctional core-double shell superparamagnetic nanoparticles (NPs) with a focus on the development of a pH-responsive drug delivery system tailored for the controlled release of Phenytoin, accompanied by real-time monitoring capabilities. In this regard, the ultra-small superparamagnetic iron oxide@silica NPs (IO@Si MNPs) were synthesized and then coated with a layer of gelatin containing Phenytoin as an antiepileptic drug. The precise saturation magnetization value for the resultant NPs was established at 26 emu g-1. The polymeric shell showed a pH-sensitive behavior with the capacity to regulate the release of encapsulated drug under neutral pH conditions, simultaneously, releasing more amount of the drug in a simulated tumorous-epileptic acidic condition. The NPs showed an average size of 41.04 nm, which is in the desired size range facilitating entry through the blood–brain barrier. The values of drug loading and encapsulation efficiency were determined to be 2.01 and 10.05%, respectively. Moreover, kinetic studies revealed a Fickian diffusion process of Phenytoin release, and diffusional exponent values based on the Korsmeyer-Peppas equation were achieved at pH 7.4 and pH 6.3. The synthesized NPs did not show any cytotoxicity. Consequently, this new design offers a faster release of PHT at the site of a tumor in response to a change in pH, which is essential to prevent epileptic attacks.

Patina formation and diffuse dispersion of alloying metals from weathering steels at urban atmospheric conditions—A combined laboratory and field investigation

AbstractThe increasing use of weathering steels (WS) has raised concerns regarding the diffuse emission of alloying elements. This research paper investigates the release of iron (Fe) and the alloying elements (Cr), copper (Cu), manganese (Mn) and nickel (Ni) from two commercially available WS at urban field conditions in Stockholm, Sweden, during 1 year and in the laboratory at simulated urban conditions. The amount of released metals is evaluated and compared with recommended levels of metals in drinking water and the formation and evolution of the protective patina is studied in parallel to assess the influence on the metal release process. Only minor amounts of the alloying elements are released and is only linked to the outermost surface composition of the patina during the very beginning of the exposure. The released amounts are found to be lower compared with the corresponding levels recommended by the World Health Organisation for drinking water.

Comparison, Simulation and Analytical Examination of the Currents of Four Different Combination Coupled Circuits with Different Solution Method

This article investigates different currents of four different coupled circuit fed sinusoidally for analytical and simulation conditions. In this paper, analytical modeling and equations for four different coupled circuit based on current point signal is presented. A discussion based on their theoretical use is then presented in the simulation along with calculations regarding their currents performances. These models are also validated by simulation results of current waveforms for each analytical case. PSpice program is used for this simulation. It has been confirmed that the analytical calculation values obtained in the analysis of the coupled circuits and the simulation plot values obtained in the Pspice analysis are the same.

Comparison, Simulation and Analytical Investigation of Voltage Current and Power Waveforms of the at Eight Different Combination Step-up and Step-down Single Phase Transformer

This article investigates different currents, voltages and powers of four different step-down and four different step-up autotransformers fed sinusoidally for analytical and simulation conditions. In this paper, analytical modeling and equations for step-down and step-up autotransformer based on current point signal and voltage polarity are presented. A discussion based on their theoretical use is then presented in the simulation along with calculations regarding their power performances. These models are also validated by simulation results of current, voltage and power waveforms for each analytical case. PSpice program is used for this simulation.

Open boundary conditions for atmospheric large-eddy simulations and their implementation in DALES4.4

Abstract. Open boundary conditions were developed for atmospheric large-eddy simulation (LES) models and implemented into the Dutch Atmospheric Large-Eddy Simulation model. The implementation was tested in a “Big Brother”-like setup, in which the simulation with open boundary conditions was forced by an identical control simulation with periodic boundary conditions. The results show that the open boundary implementation has minimal influence on the solution. Both the mean state and the turbulent structures are close to the control simulation, and disturbances at the in- and outflow boundaries are negligible. To emulate a setup in which the LES is coupled to a coarser model, the influence of coarse boundary input was tested by smoothing the output of the periodic control simulation both temporally and spatially before feeding it as input to the simulation with open boundary conditions. When smoothing is applied over larger spatial and longer temporal scales, disturbances start to form at the inflow boundary and an area exists where turbulence needs to develop. Adding synthetic turbulence to the smoothed input reduces the size of this area and the magnitude of the disturbances.

Boundary SPH for Robust Particle–Mesh Interaction in Three Dimensions

This paper introduces an algorithm to tackle the boundary condition (BC) problem, which has long persisted in the numerical and computational treatment of smoothed particle hydrodynamics (SPH). Central to the BC problem is a need for an effective method to reconcile a numerical representation of particles with 2D or 3D geometry. We describe and evaluate an algorithmic solution—boundary SPH (BSPH)—drawn from a novel twist on the mesh-based boundary method, allowing SPH particles to interact (directly and implicitly) with either convex or concave 3D meshes. The method draws inspiration from existing works in graphics, particularly discrete signed distance fields, to determine whether particles are intersecting or submerged with mesh triangles. We evaluate the efficacy of BSPH through application to several simulation environments of varying mesh complexity, showing practical real-time implementation in Unity3D and its high-level shader language (HLSL), which we test in the parallelization of particle operations. To examine robustness, we portray slip and no-slip conditions in simulation, and we separately evaluate convex and concave meshes. To demonstrate empirical utility, we show pressure gradients as measured in simulated still water tank implementations of hydrodynamics. Our results identify that BSPH, despite producing irregular pressure values among particles close to the boundary manifolds of the meshes, successfully prevents particles from intersecting or submerging into the boundary manifold. Average FPS calculations for each simulation scenario show that the mesh boundary method can still be used effectively with simple simulation scenarios. We additionally point the reader to future works that could investigate the effect of simulation parameters and scene complexity on simulation performance, resolve abnormal pressure values along the mesh boundary, and test the method’s robustness on a wider variety of simulation environments.

Estimation of planned and unplanned missing individual scores in longitudinal designs using continuous-time state-space models.

Latent change score (LCS) models within a continuous-time state-space modeling framework provide a convenient statistical approach for analyzing developmental data. In this study, we evaluate the robustness of such an approach in the context of accelerated longitudinal designs (ALDs). ALDs are especially interesting because they imply a very high rate of planned data missingness. Additionally, most longitudinal studies present unexpected participant attrition leading to unplanned missing data. Therefore, in ALDs, both sources of data missingness are combined. Previous research has shown that ALDs for developmental research allow recovering the population generating process. However, it is unknown how participant attrition impacts the model estimates. We have three goals: (a) to evaluate the robustness of the group-level parameter estimates in scenarios with empirically plausible unplanned data missingness; (b) to evaluate the performance of Kalman scores (KS) imputations for individual data points that were expected but unobserved; and (c) to evaluate the performance of KS imputations for individual data points that were outside the age ranged observed for each case (i.e., to estimate the individual trajectories for the complete age range under study). In general, results showed lack of bias in the simulated conditions. The variability of the estimates increased with lower sample sizes and higher missingness severity. Similarly, we found very accurate estimates of individual scores for both planned and unplanned missing data points. These results are very important for applied practitioners in terms of forecasting and making individual-level decisions. R code is provided to facilitate its implementation by applied researchers. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Astaxanthin supplementation ameliorates simulated heat stress by regulating physio-biochemical responses in Sirohi goats.

The present study was undertaken to assess the ameliorative effect of dietary supplementation of astaxanthin in Sirohi goats under simulated heat stress conditions. Eighteen healthy female Sirohi goats were divided equally into three groups (n = 6): Heat-Stressed Control (HSC), Treatment 1 (T1), and Treatment 2 (T2). During the experiment, goats in the T1 group were supplemented with astaxanthin at the rate of 25mg/animal/day, while those in the T2 group received supplementation of 50mg/animal/day. The experiment was conducted for 42 days: 14 days of acclimatization period, next 21 days animals were exposed to 42ºC for 6h from 09:00h to 15:00h and 7 days of recovery period. On a daily basis, we recorded the physiological responses of goats and collected environmental data at the experimental site. Blood samples were collected 0 and 14th days of acclimatization, on 1st, 6th, 11th, 16th and 21st day of heat exposure and on the 7th day of the recovery period. The rectal temperature and respiration rates of the treatment groups were lower than those of the HSC group during the exposure period. Heat stress in the supplemented groups was associated with reduced levels of hepatic enzymes such as AST and ALT. Serum urea, creatinine and albumin levels were significantly (P < 0.05) different between control and treatment groups. It was thus concluded that dietary inclusion of antioxidant astaxanthin can ameliorate induced thermal load as evident from changes in physio-biochemical parameters in the Sirohi goats, that was more prominent at 50mg/ animal/day than 25mg/ animal/day.

Minimizing Flight Hours Losses by Utilizing Deep-Q Learning Techniques in Scheduling Aircraft Maintenance

Currently, there are insufficiently good or efficient tools or procedures for long-term scheduling of aviation maintenance activities in the world, and Vietnam specifically. Airlines are impacted by a variety of elements, including the quantity of aircraft they operate, their capacity, their personnel resources, their maintenance resources, and unforeseen and urgent occurrences that cause schedule disruptions. There are no fast, automatic solutions to the above-described problems existing in aviation today. The reinforcement learning method as described here could potentially be one answer to these problems. The idea is to plan in years running across a specified period such that the aircraft is brought as close as possible to the inspection deadline. From there, the airworthiness of the aircraft increases while the maintenance inspection decreases, reducing the cost of maintenance. Application optimization of the scheduling plan is done using the Deep Q-learning method. The results achieved by the Q-learning and Deep Q-learning algorithms are better in terms of computation times as compared to the other current techniques. The research results of the checks showed reinforcement learning potential in dealing with this problem, where the fly hours loss of planned inspections was reduced by using data from Vietnam Airlines. Computational experiments show that our methods adapt for different purposes and settings of reality. After teaching the model with these simulated conditions, they show how well a reinforcement learning application quickly arrives at lean repair plans.

Fermentation of barley wort with Saccharomyces boulardii to generate a beverage with probiotic potential

Developing non-dairy functional beverages based on probiotics is a potential alternative for vegan consumers. It also becomes a big challenge since microorganisms can easily change chemical composition, acidity, color, and consumers’ acceptability. In this work, the probiotic yeast Saccharomyces boulardii was used to elaborate a fermented barley wort beverage. For the beverage formulations, the use of two flavors strawberry (SPB) and nutty (NPB) and two different inoculum concentrations (1 × 103 (SPB or NPB103) and 1 × 104 CFU/mL (SPB or NPB 104)) were considered. The fermentation was carried out at 37 °C under anaerobic conditions. The effect of the inoculum concentration was evaluated over reducing sugar consumption, the concentration of soluble solids, and pH. The best formulation was selected through a sensory evaluation. The profile of oligosaccharides and the resistance of the yeast to gastrointestinal conditions were determined only in the nutty flavor formulation (NPB 104). During the fermentation process, the content of oligosaccharides was increased compared to the unfermented wort, which improved the nutritional value. The analysis of resistance to simulated gastrointestinal conditions showed a decrease from 8.0 × 107 to 1.5 × 107 CFU/mL in the NPB 104 beverage. Barley wort is a potential medium to produce probiotic beverages with the yeast S. boulardii.

Heat stress-induced oviposition behavioral change correlates with sperm damage in the pine sawyer beetle, Monochamus alternatus.

Global climate change is causing an increase in extreme high temperatures (EHTs), which subject insects to unprecedented stress. Behavior plasticity in response to EHTs, particularly oviposition behavior, is important for the persistence and outbreak of insect populations. Investigating the plasticity of oviposition behavior and its underlying mechanisms has theoretical importance to pest management, but knowledge gaps still remain. Herein, we characterized the reproductive traits of Monochamus alternatus, a dominant insect vector of the destructive pine wilt disease, including oviposition behavioral patterns, fecundity, offspring fitness and sperm viability, under simulated heatwave conditions in the laboratory. The results showed that (i) EHTs induced a novel oviposition behavior, whereby females deposited multiple eggs into a single groove rather than laying one egg per groove under normal condition; (ii) EHTs exerted stage- and sex-specific effects on fecundity, offspring fitness and sperm viability; and (iii) there was a significant correlation between frequency of the novel oviposition strategy and sperm viability. We hypothesized that this beetle pest has the ability to flexibly shift towards a low-cost oviposition strategy to counteract the fitness costs caused by heat stress. Taken together, these findings provide a theoretical foundation for personalized pest management strategies in the context of climate change. © 2024 Society of Chemical Industry.

The effect of synbiotic coating of flaxseed mucilage‐defatted rice bran carbohydrate on quality of dried mango, viability of Bifidobacterium animalis subsp. LactisBB12 on storage and simulating gastrointestinal condition

AbstractIn the present study, a synbiotic coating of flaxseed mucilage, defatted rice bran carbohydrate, and Bifidobacterium animalis subsp. Lactis BB12 was fabricated for coating dried mango slices (M‐P‐C). The control samples contained only probiotic bacteria without coating (M‐P). Several quality parameters (moisture, weight loss, shrinkage percentage, pH, firmness, and color) were assessed on specific storage circumstances (25°C, relative humidity (RH) = 22%.). In addition, the survival of Bifidobacterium animalis subsp. Lactis BB12 was evaluated on storage and under simulated gastrointestinal (GI) conditions. According to the results, the log number of Bifidobacterium animalis subsp. Lactis BB12 reached 8.1 and 6.2 for coated and uncoated samples, respectively, during the 45 days storage at 25°C (&gt;6 log CFU (log colony‐forming units)/g) and at finished stage of in vitro gastrointestinal circumstances, the log number of probiotic bacterial count reached 6.8 and 4 for coated and uncoated samples, respectively. The coating resulted in significantly less weight loss, moisture loss, and shrinkage of the mango slices than uncoated ones (p &lt; .05). The growth of yeasts and molds was undetectable in both samples. The results of acceptance experiments for M‐P and M‐P‐C dried mango samples showedthat there were no significant differences between M‐P and M‐P‐C samples (p &gt;.05), indeed in the case of purchase intention and overall acceptability. After reading the text highlighting, there was no significant difference in all attributes of M‐P‐C samples pre and post of reading text highlighting. It could be concluded that the synbiotic coating of mango slices improved the quality characteristics of the dried mango as well as viability of the probiotic bacteria at storage time and under simulated gastrointestinal conditions.

Calibration for Improving the Medium-Range Soil Temperature Forecast of a Semiarid Region over Tibet: A Case Study

Calibration for Improving the Medium-Range Soil Temperature Forecast of a Semiarid Region over Tibet: A Case Study

Incorporating calibration errors in oral reading fluency scoring.

Oral reading fluency (ORF) assessments are commonly used to screen at-risk readers and evaluate interventions' effectiveness as curriculum-based measurements. Similar to the standard practice in item response theory (IRT), calibrated passage parameter estimates are currently used as if they were population values in model-based ORF scoring. However, calibration errors that are unaccounted for may bias ORF score estimates and, in particular, lead to underestimated standard errors (SEs) of ORF scores. Therefore, we consider an approach that incorporates the calibration errors in latent variable scores. We further derive the SEs of ORF scores based on the delta method to incorporate the calibration uncertainty. We conduct a simulation study to evaluate the recovery of point estimates and SEs of latent variable scores and ORF scores in various simulated conditions. Results suggest that ignoring calibration errors leads to underestimated latent variable score SEs and ORF score SEs, especially when the calibration sample is small.

Dynamic breakthrough performance of low concentration CO2 adsorption in fixed-bed column with porous amino acid ionic liquid composites

Low concentration carbon dioxide (CO2) capture from air or confined spaces currently faces significant challenges, such as relatively poor dynamic adsorption breakthrough performance and cyclic stability. In our previous work, functionalized ionic liquid (IL) tetraethylammonium glycine ([N2222][Gly]) and porous molecular sieve (SBA-15) were combined to synthesize porous amino acid IL composite 60 wt% [N2222][Gly]@SBA-15 with microporous and ultra-microporous structures, which provide a new pathway for low concentration CO2 capture. In order to further obtain the dynamic CO2 adsorption breakthrough performance of this material under simulated actual working conditions, the effects of temperatures, relative humidity (RH) and CO2 concentrations on CO2 adsorption and desorption breakthrough performance of 60 wt% [N2222][Gly]@SBA-15 in a fixed-bed column were systematically studied in this work. The results indicated that CO2 adsorption capacity is up to 1.81 mmolCO2/g-adsorbent at 298.15 K, 1 bar and 0 % RH under 1 vol% CO2-containing gas mixture balanced with N2 and reaches 2.44 mmolCO2/g-adsorbent at 15 % RH due to the mechanism change of CO2 reaction with primary amine from 2: 1 under dry gas to 1: 1 stoichiometry in the presence of moisture. Moreover, the adsorbent maintains good cyclic adsorption-desorption performance. Further, CO2 adsorption breakthrough behaviors were well fitted by Avrami kinetic model, and the CO2 adsorption rate of 60 wt% [N2222][Gly]@SBA-15 was controlled by intra-particle diffusion. This work implied that IL-modified adsorbents have great potentials for low concentration CO2 capture applications.

Creating Atomically Iridium-Doped PdOx Nanoparticles for Efficient and Durable Methane Abatement.

The urgent environmental concern of methane abatement, attributed to its high global warming potential, necessitates the development of methane oxidation catalysts (MOC) with enhanced low-temperature activity and durability. Herein, an iridium-doped PdOx nanoparticle supported on silicalite-1 zeolite (PdIr/S-1) catalyst was synthesized and applied for methane catalytic combustion. Comprehensive characterizations confirmed the atomically dispersed nature of iridium on the surface of PdOx nanoparticles, creating an Ir4f-O-Pdcus microstructure. The atomically doped Ir transferred more electrons to adjacent oxygen atoms, modifying the electronic structure of PdOx and thus enhancing the redox ability of the PdIr/S-1 catalysts. This electronic modulation facilitated methane adsorption on the Pd site of Ir4f-O-Pdcus, reducing the energy barrier for C-H bond cleavage and thereby increasing the reaction rate for methane oxidation. Consequently, the optimized PdIr0.1/S-1 showed outstanding low-temperature activity for methane combustion (T50 = 276 °C) after aging and maintained long-term stability over 100 h under simulated exhaust conditions. Remarkably, the novel PdIr0.1/S-1 catalyst demonstrated significantly enhanced activity even after undergoing harsh hydrothermal aging at 750 °C for 16 h, significantly outperforming the conventional Pd/Al2O3 catalyst. This work provides valuable insights for designing efficient and durable MOC catalysts, addressing the critical issue of methane abatement.

Effect of microencapsulation on the bio-preservative and probiotic properties of Enterococcus durans F21

This study aimed to assess the probiotic potential of Enterococcus durans F21 and its microencapsulation. Two microencapsulation methods, spray-drying (SD) and freeze-drying (FD), were employed using sodium caseinate (Cas) as a cell protectant at concentrations of 0.035% and 1% and at two pHs, 3 and 7. Maltodextrins (MD) served as wall material (10%). Microcapsules were analysed for cell viability and membrane damage after drying, survival under simulated gastro-intestinal conditions, antimicrobial activity, stability during storage, and physicochemical characterization. Results showed that E. durans F21 exhibited promising probiotic properties, including moderate auto-aggregation, high co-aggregation with pathogens, moderate biofilm formation, and resistance to simulated gastrointestinal conditions. The encapsulation pH showed to be a crucial factor affecting the viability of microencapsulated cells. Microencapsulation at pH 3 adversely affected cell viability during drying. However, microencapsulation at pH 7 using Cas (at 0.035 and 1%) was found to be most effective in maintaining higher cell viability under similar conditions. No significant difference was detected between both Cas formulations, suggesting that 0.035% Cas concentration might be sufficient for the microencapsulation process at pH 7. Moreover, FD proved to be the most effective method to produce E. durans F21 microcapsules with high viability (cell viability of 93%) and stability during storage (cell viability of 99%). Conclusively, microencapsulation of E. durans F21 using Cas, at pH 7, and employing FD method could be a promising strategy for producing highly viable microcapsules containing E. durans F21 cells with high probiotic and bio-preservative potentials in foods.

Survival of encapsulated and free probiotic cells Lactobacillus helveticus under different simulated conditions and in white chocolate

Survival of encapsulated and free probiotic cells Lactobacillus helveticus under different simulated conditions and in white chocolate