bluuebunny/crossref_metadata_2025 huggingface dataset:
Lasting Effects of Low to Non-Lethal Radiation Exposure during Late Gestation on Offspring’s Cardiac Metabolism and Oxidative Stress
Authors: Nemec-Bakk Ashley S. , Niccoli Sarah , Davidson Caitlund , Roy Danika , Stoa Lisa , Sreetharan Shayenthiran , Simard Alain , Boreham Douglas R. , Wilson Joanna Y. , Tai T.C. , Lees Simon J. , Khaper Neelam
Published: May 2021

Ionizing radiation (IR) is known to cause fetal programming, but the physiological effects of low-dose IR are not fully understood. This study examined the effect of low (50 mGy) to non-lethal (300 and 1000 mGy) radiation exposure during late gestation on cardiac metabolism and oxidative stress in adult offspring. Pregnant C57BL/6J mice were exposed to 50, 300, or 1000 mGy of gamma radiation or Sham irradiation on gestational day 15. Sixteen weeks after birth, 18F-Fluorodeoxyglucose (FDG) uptake was examined in the offspring using Positron Emission Tomography imaging. Western blot was used to determine changes in oxidative stress, antioxidants, and insulin signaling related proteins. Male and female offspring from irradiated dams had lower body weights when compared to the Sham. 1000 mGy female offspring demonstrated a significant increase in 18F-FDG uptake, glycogen content, and oxidative stress. 300 and 1000 mGy female mice exhibited increased superoxide dismutase activity, decreased glutathione peroxidase activity, and decreased reduced/oxidized glutathione ratio. We conclude that non-lethal radiation during late gestation can alter glucose uptake and increase oxidative stress in female offspring. These data provide evidence that low doses of IR during the third trimester are not harmful but higher, non-lethal doses can alter cardiac metabolism later in life and sex may have a role in fetal programming.
Editorial on Special Issue “Biorefinery: Current Status, Challenges, and New Strategies”
Authors: Kim Kwang Ho , Yoo Chang Geun
Published: May 2021

The overdependence on fossil fuels has raised concerns about global warming and the energy crisis, which has warranted significant research to find alternatives [...]
Central Non-Linear Model-Based Predictive Vehicle Dynamics Control
Authors: Sieberg Philipp Maximilian , Schramm Dieter
Published: May 2021

Considering automated driving, vehicle dynamics control systems are also a crucial aspect. Vehicle dynamics control systems serve as an important influence factor on safety and ride comfort. By reducing the driver’s responsibility through partially or fully automated driving functions, the occupants’ perception of safety and ride comfort changes. Both aspects are focused even more and have to be enhanced. In general, research on vehicle dynamics control systems is a field that has already been well researched. With regard to the mentioned aspects, however, a central control structure features sufficient potential by exploiting synergies. Furthermore, a predictive mode of operation can contribute to achieve these objectives, since the vehicle can act in a predictive manner instead of merely reacting. Consequently, this contribution presents a central predictive control system by means of a non-linear model-based predictive control algorithm. In this context, roll, self-steering and pitch behavior are considered as control objectives. The active roll stabilization demonstrates an excellent control quality with a root mean squared error of 7.6953×10−3 rad averaged over both validation maneuvers. Compared to a vehicle utilizing a conventional control approach combined with a skyhook damping, pitching movements are reduced by 19.75%. Furthermore, an understeering behavior is maintained, which corresponds to the self-steering behavior of the passive vehicle. In general, the central predictive control, thus, increases both ride comfort and safety in a holistic way.
Trimethoxycinnamates and Their Cholinesterase Inhibitory Activity
Authors: Kos Jiri , Strharsky Tomas , Stepankova Sarka , Svrckova Katarina , Oravec Michal , Hosek Jan , Imramovsky Ales , Jampilek Josef
Published: May 2021

A series of twelve nature-inspired 3,4,5-trimethoxycinnamates were prepared and characterized. All compounds, including the starting 3,4,5-trimethoxycinnamic acid, were tested for their ability to inhibit acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) in vitro; the selectivity index (SI) was also determined. 2-Fluororophenyl (2E)-3-(3,4,5-trimethoxyphenyl)-prop-2-enoate demonstrated the highest SI (1.71) in favor of BChE inhibition. 2-Chlorophenyl (2E)-3-(3,4,5-trimethoxyphenyl)prop-2-enoate showed the highest AChE-inhibiting (IC50 = 46.18 µM) as well as BChE-inhibiting (IC50 = 32.46 µM) activity with an SI of 1.42. The mechanism of action of the most potent compound was determined by the Lineweaver–Burk plot as a mixed type of inhibition. An in vitro cell viability assay confirmed the insignificant cytotoxicity of the discussed compounds on the two cell lines. Trends between structure, physicochemical properties and activity were discussed.
The Effect of Dust Transport on the Concentration of Chlorophyll-A in the Surface Layer of the Black Sea
Authors: Varenik Alla V. , Kalinskaya Darya V.
Published: May 2021

This paper focuses on the atmospheric dust transport effect on the changes in chlorophyll-A concentration in the Black Sea surface layer. In order to assess the input of nutrients with atmospheric precipitations at the Crimean coast of the Black Sea, the collected samples were analyzed for the content of inorganic nitrogen, phosphates, and silicon. The samples were taken into a wet-only sampler and into a permanently open one, to assess the effect of dust on the nutrients concentration in dry depositions. Cases of multi-fold excess of the nutrients content in the open sampler collected precipitation over that in the wet-only sampler were identified. For such high concentration cases, the 7-day back-trajectories analyses was carried out using the model of the international network AERONET and the HYSPLIT model. The results of our research showed that the influx of nutrients with the atmospheric depositions can result in increasing of chlorophyll-A concentration in 11–36% in the surface layer of the Black Sea. After atmospheric depositions, concentration of phosphates in the surface layer can increase more than five times compared with the background concentration. The increase of silicon concentration can reach 30%. The influx of atmospheric precipitation containing significant amounts of nutrients into the bay can shifts the Redfield ratio compared with background value up to three times.
Cellulose Recovery from Agri-Food Residues by Effective Cavitational Treatments
Authors: Verdini Federico , Calcio Gaudino Emanuela , Grillo Giorgio , Tabasso Silvia , Cravotto Giancarlo
Published: May 2021

Residual biomass from agri-food production chain and forestry are available in huge amounts for further valorisation processes. Delignification is usually the crucial step in the production of biofuels by fermentation as well as in the conversion of cellulose into high added-value compounds. High-intensity ultrasound (US) and hydrodynamic cavitation (HC) have been widely exploited as effective pretreatment techniques for biomass conversion and in particular for cellulose recovery. Due to their peculiar mechanisms, cavitational treatments promote an effective lignocellulosic matrix dismantling with delignification at low temperature (35–50 °C). Cavitation also promotes cellulose decrystallization due to a partial depolymerization. The aim of this review is to highlight recent advances in US and HC-assisted delignification and further cellulose recovery and valorisation.
Geometry and Distortion Prediction of Multiple Layers for Wire Arc Additive Manufacturing with Artificial Neural Networks
Authors: Wacker Christian , Köhler Markus , David Martin , Aschersleben Franziska , Gabriel Felix , Hensel Jonas , Dilger Klaus , Dröder Klaus
Published: May 2021

Wire arc additive manufacturing (WAAM) is a direct energy deposition (DED) process with high deposition rates, but deformation and distortion can occur due to the high energy input and resulting strains. Despite great efforts, the prediction of distortion and resulting geometry in additive manufacturing processes using WAAM remains challenging. In this work, an artificial neural network (ANN) is established to predict welding distortion and geometric accuracy for multilayer WAAM structures. For demonstration purposes, the ANN creation process is presented on a smaller scale for multilayer beads on plate welds on a thin substrate sheet. Multiple concepts for the creation of ANNs and the handling of outliers are developed, implemented, and compared. Good results have been achieved by applying an enhanced ANN using deformation and geometry from the previously deposited layer. With further adaptions to this method, a prediction of additive welded structures, geometries, and shapes in defined segments is conceivable, which would enable a multitude of applications for ANNs in the WAAM-Process, especially for applications closer to industrial use cases. It would be feasible to use them as preparatory measures for multi-segmented structures as well as an application during the welding process to continuously adapt parameters for a higher resulting component quality.
Path Planning for Localization of Radiation Sources Based on Principal Component Analysis
Authors: Kishimoto Takuya , Woo Hanwool , Komatsu Ren , Tamura Yusuke , Tomita Hideki , Shimazoe Kenji , Yamashita Atsushi , Asama Hajime
Published: May 2021

In this paper, we propose a path planning method for the localization of radiation sources using a mobile robot equipped with an imaging gamma-ray detector, which has a field of view in all directions. The ability to detect and localize radiation sources is essential for ensuring nuclear safety, security, and surveillance. To enable the autonomous localization of radiation sources, the robot must have the ability to automatically determine the next location for gamma ray measurement instead of following a predefined path. The number of incident events is approximated to be the squared inverse proportional to the distance between the radiation source and the detector. Therefore, the closer the distance to the source, the shorter the time required to obtain the same radiation counts measured by the detector. Hence, the proposed method is designed to reduce this distance to a position where a sufficient number of gamma-ray events can be obtained; then, a path to surround the radiation sources is generated. The proposed method generates this path by performing principal component analysis based on the results obtained from previous measurements. Both simulations and actual experiments demonstrate that the proposed method can automatically generate a measurement path and accurately localize radiation sources.
Comments on the Navier–Stokes Problem
Authors: Ramm Alexander
Published: May 2021

The aim of this paper is to explain for broad audience the author’s result concerning the Navier–Stokes problem (NSP) in R3 without boundaries. It is proved that the NSP is contradictory in the following sense: if one assumes that the initial data v(x,0)≢0, ∇·v(x,0)=0 and the solution to the NSP exists for all t≥0, then one proves that the solution v(x,t) to the NSP has the property v(x,0)=0. This paradox shows that the NSP is not a correct description of the fluid mechanics problem and the NSP does not have a solution. In the exceptional case, when the data are equal to zero, the solution v(x,t) to the NSP exists for all t≥0 and is equal to zero, v(x,t)≡0. Thus, one of the millennium problems is solved.
Mathematical Approach for System Repair Rate Analysis Used in Maintenance Decision Making
Authors: Kontrec Nataša , Panić Stefan , Panić Biljana , Marković Aleksandar , Stošović Dejan
Published: May 2021

Reliability, the number of spare parts and repair time have a great impact on system availability. In this paper, we observed a repairable system comprised of several components. The aim was to determine the repair rate by emphasizing its stochastic nature. A model for the statistical analysis of the component repair rate in function of the desired level of availability is presented. Furthermore, based on the presented model, the approach for the calculation of probability density functions of maximal and minimal repair times for a system comprised of observed components was developed as an important measure that unambiguously defines the total annual repair time. The obtained generalized analytical expressions that can be used to predict the total repair time for an observed entity are the main contributions of the manuscript. The outputs of the model can be useful for making decisions in which time interval repair or replacement should be done to maintain the system and component availability. In addition to planning maintenance activities, the presented models could be used for service capacity planning and the dynamic forecasting of system characteristics.
Factors Influencing the Formation of Sodium Hydroxide by an Ion Exchange Membrane Cell
Authors: Rosales-Huamani Jimmy Aurelio , Medina-Collana Juan Taumaturgo , Diaz-Cordova Zoila Margarita , Montaño-Pisfil Jorge Alberto
Published: May 2021

The present study aimed to evaluate the factors that influence the formation of sodium hydroxide (NaOH) by means of an electrolytic cell with ion exchange membranes. To achieve this experiment, the NaOH production cell had to be designed and built inexpensively, using graphite electrodes. The operational parameters in our study were: initial NaOH concentration, applied voltage, and temperature. All experiments were carried out using model NaCl solutions with a concentration of 40 g/L for 150 min. The results of the experiment were that the NaOH concentration, conductivity, and pH presented an increasing linear trend with the electrolysis time. Finally, it was possible to obtain the efficiency level of the electric current in our investigation, which was an average of 80.2%, that indicated good performance of the built cell.
The Insulin Receptor: A Potential Target of Amarogentin Isolated from Gentiana rigescens Franch That Induces Neurogenesis in PC12 Cells
Authors: Cheng Lihong , Osada Hiroyuki , Xing Tianyan , Yoshida Minoru , Xiang Lan , Qi Jianhua
Published: May 2021

Amarogentin (AMA) is a secoiridoid glycoside isolated from the traditional Chinese medicine, Gentiana rigescens Franch. AMA exhibits nerve growth factor (NGF)-mimicking and NGF-enhancing activities in PC12 cells and in primary cortical neuron cells. In this study, a possible mechanism was found showing the remarkable induction of phosphorylation of the insulin receptor (INSR) and protein kinase B (AKT). The potential target of AMA was predicted by using a small-interfering RNA (siRNA) and the cellular thermal shift assay (CETSA). The AMA-induced neurite outgrowth was reduced by the siRNA against the INSR and the results of the CETSA suggested that the INSR showed a significant thermal stability-shifted effect upon AMA treatment. Other neurotrophic signaling pathways in PC12 cells were investigated using specific inhibitors, Western blotting and PC12(rasN17) and PC12(mtGAP) mutants. The inhibitors of the glucocorticoid receptor (GR), phospholipase C (PLC) and protein kinase C (PKC), Ras, Raf and mitogen-activated protein kinase (MEK) significantly reduced the neurite outgrowth induced by AMA in PC12 cells. Furthermore, the phosphorylation reactions of GR, PLC, PKC and an extracellular signal-regulated kinase (ERK) were significantly increased after inducing AMA and markedly decreased after treatment with the corresponding inhibitors. Collectively, these results suggested that AMA-induced neuritogenic activity in PC12 cells potentially depended on targeting the INSR and activating the downstream Ras/Raf/ERK and PI3K/AKT signaling pathways. In addition, the GR/PLC/PKC signaling pathway was found to be involved in the neurogenesis effect of AMA.
The 3Rs Principle in Animal Experimentation: A Legal Review of the State of the Art in Europe and the Case in Italy
Authors: Maestri Enrico
Published: May 2021

The aim of this paper is to describe the essential points of Italian and European legislation governing the use of animals in biomedical experimentation. A close look will be taken at the principles of the 3Rs, which represent the mainstay of the legal architecture based on which a correct interpretation may be drawn of the legislative documents on animal experimentation. Furthermore, this paper will address the ways in which Directive 2010/63/EU is implemented in Italian legislation on the welfare of laboratory animals. In addition to an assessment of legal issues (such as the scope of jurisdiction of supervisory authorities tasked with issuing authorizations), it will include a discussion of cases of inadequate and insufficient implementation of the requirements laid down by Directive 2010/63/EU. Both the consistency of the interpretation of national legislation with the Directive and the direct effectiveness of the Directive in national law, in which animal testing has been and still is the subject of heated debate between supporters and opponents, will be examined.
A Biplot-Based PCA Approach to Study the Relations between Indoor and Outdoor Air Pollutants Using Case Study Buildings
Authors: Zhang He , Srinivasan Ravi
Published: May 2021

The 24 h and 14-day relationship between indoor and outdoor PM2.5, PM10, NO2, relative humidity, and temperature were assessed for an elementary school (site 1), a laboratory (site 2), and a residential unit (site 3) in Gainesville city, Florida. The primary aim of this study was to introduce a biplot-based PCA approach to visualize and validate the correlation among indoor and outdoor air quality data. The Spearman coefficients showed a stronger correlation among these target environmental measurements on site 1 and site 2, while it showed a weaker correlation on site 3. The biplot-based PCA regression performed higher dependency for site 1 and site 2 (p < 0.001) when compared to the correlation values and showed a lower dependency for site 3. The results displayed a mismatch between the biplot-based PCA and correlation analysis for site 3. The method utilized in this paper can be implemented in studies and analyzes high volumes of multiple building environmental measurements along with optimized visualization.
Non-Precious Metal Electrocatalysts: Synthesis, Characterization and Application
Authors: Mikołajczyk Tomasz
Published: May 2021

Electrocatalysis plays a vital role in many chemical processes and is concentrated on improving their efficiency [...]
Having an Old Friend for Dinner: The Interplay between Apoptotic Cells and Efferocytes
Authors: Lam Austin Le , Heit Bryan
Published: May 2021

Apoptosis, the programmed and intentional death of senescent, damaged, or otherwise superfluous cells, is the natural end-point for most cells within multicellular organisms. Apoptotic cells are not inherently damaging, but if left unattended, they can lyse through secondary necrosis. The resulting release of intracellular contents drives inflammation in the surrounding tissue and can lead to autoimmunity. These negative consequences of secondary necrosis are avoided by efferocytosis—the phagocytic clearance of apoptotic cells. Efferocytosis is a product of both apoptotic cells and efferocyte mechanisms, which cooperate to ensure the rapid and complete removal of apoptotic cells. Herein, we review the processes used by apoptotic cells to ensure their timely removal, and the receptors, signaling, and cellular processes used by efferocytes for efferocytosis, with a focus on the receptors and signaling driving this process.
Establishing a 3D In Vitro Hepatic Model Mimicking Physiologically Relevant to In Vivo State
Authors: Kang Hyun Kyoung , Sarsenova Madina , Kim Da-Hyun , Kim Min Soo , Lee Jin Young , Sung Eun-Ah , Kook Myung Geun , Kim Nam Gyo , Choi Soon Won , Ogay Vyacheslav , Kang Kyung-Sun
Published: May 2021

Three-dimensional (3D) bioprinting is a promising technology to establish a 3D in vitro hepatic model that holds great potential in toxicological evaluation. However, in current hepatic models, the central area suffers from hypoxic conditions, resulting in slow and weak metabolism of drugs and toxins. It remains challenging to predict accurate drug effects in current bioprinted hepatic models. Here, we constructed a hexagonal bioprinted hepatic construct and incorporated a spinning condition with continuous media stimuli. Under spinning conditions, HepG2 cells in the bioprinted hepatic construct exhibited enhanced proliferation capacity and functionality compared to those under static conditions. Additionally, the number of spheroids that play a role in boosting drug-induced signals and responses increased in the bioprinted hepatic constructs cultured under spinning conditions. Moreover, HepG2 cells under spinning conditions exhibited intensive TGFβ-induced epithelial-to-mesenchymal transition (EMT) and increased susceptibility to acetaminophen (APAP)-induced hepatotoxicity as well as hepatotoxicity prevention by administration of N-acetylcysteine (NAC). Taken together, the results of our study demonstrate that the spinning condition employed during the generation of bioprinted hepatic constructs enables the recapitulation of liver injury and repair phenomena in particular. This simple but effective culture strategy facilitates bioprinted hepatic constructs to improve in vitro modeling for drug effect evaluation.
Successful Postnatal Cardiopulmonary Resuscitation Due to Defibrillation
Authors: Mileder Lukas Peter , Morris Nicholas Mark , Kurath-Koller Stefan , Pansy Jasmin , Pichler Gerhard , Pocivalnik Mirjam , Schwaberger Bernhard , Burmas Ante , Urlesberger Berndt
Published: May 2021

An asphyxiated term neonate required postnatal resuscitation. After six minutes of cardio-pulmonary resuscitation (CPR) and two doses of epinephrine, spontaneous circulation returned, but was shortly followed by ventricular fibrillation. CPR and administration of magnesium, calcium gluconate, and sodium bicarbonate did not improve the neonate’s condition. A counter shock of five Joule was delivered and the cardiac rhythm immediately converted to sinus rhythm. The neonate was transferred to the neonatal intensive care unit and received post-resuscitation care. Due to prolonged QTc and subsequently suspected long-QT syndrome propranolol treatment was initiated. The neonate was discharged home on day 14 without neurological sequelae.
Macronutrient Intake in Pregnancy and Child Cognitive and Behavioural Outcomes
Authors: Taylor Rachael M. , Blumfield Michelle L. , Ashton Lee M. , Hure Alexis J. , Smith Roger , Buckley Nick , Drysdale Karen , Collins Clare E.
Published: May 2021

Prenatal nutrient exposures can impact on brain development and disease susceptibility across the lifespan. It is well established that maternal macronutrient intake during pregnancy influences foetal and infant development. Therefore, we hypothesise that macronutrient intakes during pregnancy are correlated with cognitive development during early childhood. The current study aimed to investigate the relationship between maternal macronutrient intake during pregnancy and child cognitive and behavioural outcomes at age 4 years. We analysed prospective data from a cohort of 64 Australian mother–child dyads. Maternal macronutrient intake was assessed using a validated 74-item food frequency questionnaire at 2 timepoints during pregnancy. Child cognition and behaviour were measured at age 4 years using the validated Wechsler Preschool and Primary Scale of Intelligence, 3rd version (WPPSI-III) and the Child Behaviour Checklist (CBC). Linear regression models were used to quantify statistical relationships and were adjusted for maternal age, education, pre-pregnancy BMI, breastfeeding duration and birthweight. Child Performance IQ was inversely associated with maternal starch intake (b = −11.02, p = 0.03). However, no other associations were found. Further research is needed to explore the association between different types of starch consumed during pregnancy and child cognitive development.
Active Biopolymeric Films Inoculated with Bdellovibrio bacteriovorus, a Predatory Bacterium
Authors: Sáenz-Santos Christian Mariel , Opemipo Oyedara Omotayo , García-Tejeda Yunia Verónica , Romero-Bastida Claudia A. , García-Oropesa Esperanza Milagros , Villalobo Eduardo , Rodríguez-Pérez Mario A.
Published: May 2021

The objective of the present work was to evaluate novel active films made with biopolymeric matrices as carriers of a living Bdellovibrio bacteriovorus HD100 strain, a predatory bacterium with antimicrobial potentials against pathogens. Biopolymer films were prepared by a casting method using the following mixtures: collagen/sodium alginate/sorbitol (CA-S), collagen/sodium alginate/glycerol (CA-G), and tapioca starch/sodium alginate/glycerol (StA-G). The effects of the film formulations on the viability of the B. bacteriovorus was investigated by using Fourier Transform Infrared (FTIR) spectroscopy, Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM). SEM showed that Bdellovibrio bacteriovorus morphology was not altered in the polymeric films. FTIR spectroscopy provided information about the structural composition of the films. CA-S showed less reduction in the viability of B. bacteriovorus after its entrapment; thus, CA-S proved to be a better agent for the immobilization and preservation of B. bacteriovorus to enhance its predatory activities during application against Escherichia coli.
Microstructural and Mechanical Properties of B-Cr Coatings Formed on 145Cr6 Tool Steel by Laser Remelting of Diffusion Borochromized Layer Using Diode Laser
Authors: Bartkowska Aneta , Bartkowski Dariusz , Przestacki Damian , Hajkowski Jakub , Miklaszewski Andrzej
Published: May 2021

The paper presents study results focused on the microstructural, mechanical, and physicochemical properties of B-Cr coatings obtained by means of modification of diffusion borochromized layers by diode laser beam. The studies were conducted on 145Cr6 tool steel. Diffusion borochromized layers were produced at 950 °C in powder mixture containing boron carbides as a source of boron and ferrochrome as a source of chromium. In the next step these layers were remelted using laser beam. Powers: 600, 900, and 1200 W were used during these processes. The microstructure, microhardness, chemical composition, as well as wear and corrosion resistance of newly-formed B-Cr coatings were determined. As a result of laser beam interaction, the diffusion borochromized layer was mixed with the steel substrate. The study showed that too low laser beam power causes cracks in the newly formed B-Cr coating, and on the other hand, too higher laser beam power causes deep remelting resulting in the loss of microhardness. The reduced corrosion resistance in comparison with diffusion borochromized layers was caused by occurrence cracks or deep remelting. For B-Cr coatings produced using laser beam power 600 W, a small decrease in wear resistance was observed, but note that this coating was much thicker than diffusion borochromized layers. On the other hand, laser beam power of 1200 W caused a significant decrease in wear resistance. Newly formed B-Cr coatings had an advantageous microhardness gradient between the layer and the substrate.
Monolayers of Cholesterol and Cholesteryl Stearate at the Water/Vapor Interface: A Physico-Chemical Study of Components of the Meibum Layer
Authors: Rubio Ramón G. , Guzmán Eduardo , Ortega Francisco , Liggieri Libero
Published: May 2021

Langmuir monolayers containing different amounts of cholesterol and cholesteryl stearate were studied at two different temperatures (24 °C and 35 °C). The main goal was to contribute towards the understanding of how the variations in the chemical composition may affect the physico-chemical properties of these specific lipid monolayers. The model mixture was chosen considering that cholesteryl esters are present in cell membranes and some other biological systems, including human tear lipids. Therefore, an investigation into the effect of the lipid monolayer composition on their interfacial properties may elucidate some of the fundamental reasons for the deficiencies in cell membranes and tear film functioning in vivo. The experimental results have shown that the molar ratio of the mixture plays a crucial role in the modulation of the Langmuir film properties. The condensing effects of the cholesterol and the interactions between the lipids in the monolayer were the main factors altering the monolayer response to dilatational deformation. The modification of the mixture compositions leads to significant changes in the Langmuir films and the mechanical performance, altering the ability of the monolayer to reduce the surface tension and the viscoelastic properties of the monolayers. This suggests that subtle modifications of the biomembrane composition may significantly alter its physiological function.
Processing Analysis of Swift Playgrounds in a Children’s Computational Thinking Course to Learn Programming
Authors: Cheng Guo-Ming , Chen Chia-Pin
Published: May 2021

Computational thinking courses can cultivate students’ ability to apply logic in the fields of mathematics and information science. The new 12-year Basic Education Curriculum Guidelines were implemented in Fall 2019 in Taiwan. Courses on computational thinking, problem solving, and programming are contained in the technology education field in junior and senior high schools. Swift Playgrounds is an innovative app for the iPad and Mac that makes learning Swift interactive and fun. No programming knowledge is required to use Swift Playgrounds, making it very suitable for beginners. This study was carried out by letting elementary school teachers and students participate in Swift Playgrounds computational thinking courses. By trying this app, teachers of different disciplines attempted to realize more learning situations. Students learned how to cope with functions and loop skills by playing with “Byte”, which is a character in Swift Playgrounds. There were three purposes for this study: first, designing a computational thinking course for the most basic part, “Hello! Byte”, in Swift Playgrounds; second, assigning elementary school teachers to assess the qualitative analysis of tasks in Swift Playgrounds; and third, assigning elementary school students to do the tasks and assign a difficulty index in Swift Playgrounds after learning with this app. The results show that most teachers considered this approach to be able to improve logical thinking and inferential capability after assessing, and most students considered functions and loops quite difficult after using the app. According to the students’ indices, about 86 percent of students considered that adding commands is easy, and about 37 percent of students considered that functions are easy. On the other hand, about 24 percent of students considered that applying the Slotted Stairways is difficult, and about 34 percent of students considered that using loops is hard. It is suggested that more instructions for the course or extendibility for classes is required.
3D-FEM Simulation of Hot Rolling Process and Characterization of the Resultant Microstructure of a Light-Weight Mn Steel
Authors: González-Castillo Ana Claudia , Cruz-Rivera José de Jesús , Ramos-Azpeitia Mitsuo Osvaldo , Garnica-González Pedro , Garay-Reyes Carlos Gamaliel , Pacheco-Cedeño José Sergio , Hernández-Rivera José Luis
Published: May 2021

Computational simulation has become more important in the design of thermomechanical processing since it allows the optimization of associated parameters such as temperature, stresses, strains and phase transformations. This work presents the results of the three-dimensional Finite Element Method (FEM) simulation of the hot rolling process of a medium Mn steel using DEFORM-3D software. Temperature and effective strain distribution in the surface and center of the sheet were analyzed for different rolling passes; also the change in damage factor was evaluated. According to the hot rolling simulation results, experimental hot rolling parameters were established in order to obtain the desired microstructure avoiding the presence of ferrite precipitation during the process. The microstructural characterization of the hot rolled steel was carried out using optical microscopy (OM), scanning electron microscopy (SEM) and X-ray diffraction (XRD). It was found that the phases present in the steel after hot rolling are austenite and α′-martensite. Additionally, to understand the mechanical behavior, tensile tests were performed and concluded that this new steel can be catalogued in the third automotive generation.
Recursive Genetic Micro-Aggregation Technique: Information Loss, Disclosure Risk and Scoring Index
Authors: Fayyoumi Ebaa , Alhuniti Omar
Published: May 2021

This research investigates the micro-aggregation problem in secure statistical databases by integrating the divide and conquer concept with a genetic algorithm. This is achieved by recursively dividing a micro-data set into two subsets based on the proximity distance similarity. On each subset the genetic operation “crossover” is performed until the convergence condition is satisfied. The recursion will be terminated if the size of the generated subset is satisfied. Eventually, the genetic operation “mutation” will be performed over all generated subsets that satisfied the variable group size constraint in order to maximize the objective function. Experimentally, the proposed micro-aggregation technique was applied to recommended real-life data sets. Results demonstrated a remarkable reduction in the computational time, which sometimes exceeded 70% compared to the state-of-the-art. Furthermore, a good equilibrium value of the Scoring Index (SI) was achieved by involving a linear combination of the General Information Loss (GIL) and the General Disclosure Risk (GDR).
Systemic Sclerosis-Associated Pulmonary Hypertension: Spectrum and Impact
Authors: Naranjo Mario , Hassoun Paul M.
Published: May 2021

Systemic sclerosis-associated pulmonary arterial hypertension (SSc-PAH) is a catastrophic complication of one of the most common and devastating autoimmune diseases. Once diagnosed, it becomes the leading cause of mortality among this patient population. Screening modalities and risk assessments have been designed and validated by various organizations and societies in order to identify patients early in their disease course and promptly refer them to expert centers for a hemodynamic assessment and formal diagnosis. Moreover, several large multicenter clinical trials have now included patients with SSc-PAH to assess their response to therapy. Despite an improved understanding of the condition and significant advances in supportive and targeted therapy, outcomes have remained far from optimal. Therefore, rigorous phenotyping and search for novel therapies are desperately needed for this devastating condition.
A Survey Study on U.S. College Students’ Learning Experience in COVID-19
Authors: Zhou Jiahua , Zhang Qiping
Published: May 2021

COVID-19 affected various aspects of our life. Many college students were forced to take courses remotely. It was not clear how they adapted to this new environment and how their mental health was affected. The objective of this study is to understand college students’ learning experience one year after the outbreak of COVID-19. An online survey was developed to investigate students’ overall learning process, mental health, perception of the learning community and student support. Sixty-two college students in the U.S. were recruited through an online survey platform. Findings of this study revealed: (1) improved mental health of college students compared to the beginning of the pandemic; (2) an overall positive learning experience and perceived belongingness to their learning community, as well as high satisfaction with the student support; (3) the major hindrance in the online learning environment was the lack of interactions with teachers and classmates; (4) a relationship between family income and perception of the learning community was discovered, and the students from low-income families were found to feel more belonging to the learning community; (5) hybrid was the optimum learning mode during COVID-19; (6) on-campus students perceived more student support than off-campus students. These findings provided a guideline for future research to further explore, and improve, the online learning environment.
Using PLS-SEM Model to Explore the Influencing Factors of Learning Satisfaction in Blended Learning
Authors: Huang Chun-Hsiung
Published: May 2021

This research explores the influencing factors of learning satisfaction in blended learning. Three dimensions are proposed: perceived usefulness, perceived ease of use, and learning motivation. It studied how these variables affect students’ learning satisfaction. The research hypotheses are: (1) Perceived ease of use positively affects perceived usefulness; (2) Perceived usefulness and perceived ease of use will have a positive effect on learning motivation; (3) Learning motivation positively affects learning satisfaction; (4) Perceived usefulness has a positive intermediary effect on the relationship between perceived ease of use and learning motivation. Participants included 173 freshmen who took the first-year interactive game design course at Ling Tung University in Taichung, Taiwan. The questionnaire survey method is applied in this research to analyze the relationship between the variables and verify the hypothesis based on the collected 173 valid questionnaires. The partial least square method structural equation model (PLS-SEM) is used to carry out structural equation modeling to study the relationship between latent variables. It explains that the perceived ease of use affects the perceived usefulness. Perceived usefulness and perceived ease of use have a positive impact on learning motivation. Learning motivation has a positive impact on learning satisfaction. Perceived usefulness as an intermediary factor of perceived ease of use has an indirect impact on learning motivation. The contribution of this research is to provide empirical evidence and explain what factors may affect learning satisfaction. Some other related factors that may affect learning satisfaction should be taken as the factors that teachers should pay attention to when implementing blended learning.
Approaches towards Blockchain Innovation: A Survey and Future Directions
Authors: Guru Divya , Perumal Supraja , Varadarajan Vijayakumar
Published: May 2021

A blockchain is a decentralized peer to peer platform which provides security services based on some key concepts, namely authentication, confidentiality, integrity and authorization. It is the process of recording and keeping track of the resources without the intervention of a centralized authority. This paper provides an overview of blockchains, the structure of blockchains, consensus algorithms, etc., It compares the algorithms based on their utility and limitations. Though blockchains provide secure communication, there are some minimal data leaks which are discussed. Various security issues in blockchains are discussed such as denial of service attacks, etc., In addition to security, some other blockchain challenges are presented like scalability, reliability, interoperability, privacy and consensus mechanisms for integration with AI, IoT and edge computing. This paper also explains about the importance of blockchains in the fields of smart healthcare, smart grid, and smart financial systems. Overall, this paper gives the glimpse of various protocols, algorithms, applications, challenges and opportunities that are found in the blockchain domain.
Cybersafety Approach to Cybersecurity Analysis and Mitigation for Mobility-as-a-Service and Internet of Vehicles
Authors: Lee Chee Wei , Madnick Stuart
Published: May 2021

Urban mobility is in the midst of a revolution, driven by the convergence of technologies such as artificial intelligence, on-demand ride services, and Internet-connected and self-driving vehicles. Technological advancements often lead to new hazards. Coupled with the increased levels of automation and connectivity in the new generation of autonomous vehicles, cybersecurity is emerging as a key threat affecting these vehicles. Traditional hazard analysis methods treat safety and security in isolation and are limited in their ability to account for interactions among organizational, sociotechnical, human, and technical components. In response to these challenges, the cybersafety method, based on System Theoretic Process Analysis (STPA and STPA-Sec), was developed to meet the growing need to holistically analyze complex sociotechnical systems. We applied cybersafety to coanalyze safety and security hazards, as well as identify mitigation requirements. The results were compared with another promising method known as Combined Harm Analysis of Safety and Security for Information Systems (CHASSIS). Both methods were applied to the Mobility-as-a-Service (MaaS) and Internet of Vehicles (IoV) use cases, focusing on over-the-air software updates feature. Overall, cybersafety identified additional hazards and more effective requirements compared to CHASSIS. In particular, cybersafety demonstrated the ability to identify hazards due to unsafe/unsecure interactions among sociotechnical components. This research also suggested using CHASSIS methods for information lifecycle analysis to complement and generate additional considerations for cybersafety. Finally, results from both methods were backtested against a past cyber hack on a vehicular system, and we found that recommendations from cybersafety were likely to mitigate the risks of the incident.
Traffic Flow Management of Autonomous Vehicles Using Platooning and Collision Avoidance Strategies
Authors: Mushtaq Anum , Haq Irfan ul , Nabi Wajih un , Khan Asifullah , Shafiq Omair
Published: May 2021

Connected Autonomous Vehicles (AVs) promise innovative solutions for traffic flow management, especially for congestion mitigation. Vehicle-to-Vehicle (V2V) communication depends on wireless technology where vehicles can communicate with each other about obstacles and make cooperative strategies to avoid these obstacles. Vehicle-to-Infrastructure (V2I) also helps vehicles to make use of infrastructural components to navigate through different paths. This paper proposes an approach based on swarm intelligence for the formation and evolution of platoons to maintain traffic flow during congestion and collision avoidance practices using V2V and V2I communications. In this paper, we present a two level approach to improve traffic flow of AVs. At the first level, we reduce the congestion by forming platoons and study how platooning helps vehicles deal with congestion or obstacles in uncertain situations. We performed experiments based on different challenging scenarios during the platoon’s formation and evolution. At the second level, we incorporate a collision avoidance mechanism using V2V and V2I infrastructures. We used SUMO, Omnet++ with veins for simulations. The results show significant improvement in performance in maintaining traffic flow.
Operational Testing of a Solid Fuel Boiler with Different Fuels
Authors: Érces Norbert , Kajtár László
Published: May 2021

In the course of our investigations, we burned high-quality logs as well as wood briquettes in a conventional, manually fed mixed-fired boiler, under different operating parameters. Based on the evaluation of the measurement results, there is a significant difference in terms of recoverable energy and carbon monoxide emissions for the two fuels burned in the same device at different air supply parameters. Studies have shown that a constantly changing position of the draft control door has an adverse effect on carbon monoxide emissions as well as the energy produced. In the case of a constant draft door setting, the preset values that can be considered ideal for energy yield and CO emissions were determined for the two fuel types. The obtained results were compared with the requirements according to the MSZ EN 303-5 standard.
Influence of Emulsifiers and Dairy Ingredients on Manufacturing, Microstructure, and Physical Properties of Butter
Authors: Panchal Bhavesh , Truong Tuyen , Prakash Sangeeta , Bansal Nidhi , Bhandari Bhesh
Published: May 2021

The influence of emulsifiers and dairy solids on churning and physical attributes of butter was investigated. Commercial dairy cream was blended with each of the ingredients (0.5%, w/w) separately, aged overnight (10 °C), and churned (10 °C) into butter. The employed additives showed a distinctive impact on the macroscopic properties of butter without largely affecting the melting behavior. In fresh butter, polyglycerol polyricinoleate (PGPR) emulsifier having dominated hydrophobic moieties significantly (p < 0.05) enhanced the softness. Among dairy solids, sodium caseinate (SC) was the most effective in reducing the solid fat fraction, hardness, and elastic modulus (G’), while whey protein isolate (WPI) and whole milk powder (WMP) produced significantly harder, stiffer, and more adhesive butter texture. As per tribological analysis, PGPR, Tween 80, and SC lowered the friction-coefficient of butter, indicating an improved lubrication property of the microstructure. The extent of butter-setting during 28 days of storage (5 °C) varied among the samples, and in specific, appeared to be delayed in presence of WPI, WMP, and buttermilk solids. The findings of the study highlighted the potential of using applied emulsifiers and dairy-derived ingredients in modifying the physical functionality of butter and butter-like churned emulsions in addition to a conventional cream-ageing process.
Evaluation of the Antioxidant Activity, Deodorizing Effect, and Antibacterial Activity of ‘Porotan’ Chestnut By-Products and Establishment of a Compound Paper
Authors: Tsurunaga Yoko , Takahashi Tetsuya
Published: May 2021

Chestnuts are widely cultivated for their edible portion (kernel), whereas the non-edible parts are discarded. To enable the utilization of the by-products of processed chestnuts, we separated them into green and brown burs, shells, inner skin, and leaves, and analyzed the bioactive properties of the ground components. We also created a composite paper, comprising the inner skin, and examined its deodorant properties. It was revealed that the inner skin had the highest functionality and showed potent antioxidant, antibacterial, and deodorant properties. Furthermore, when we produced a paper, containing 60% inner skin, and examined its deodorant properties, we found that it was highly effective in deodorizing ammonia and acetic acid gases. These results show that the inner skin of chestnuts is a promising material for developing hygiene and other products.