bluuebunny/crossref_metadata_2025 huggingface dataset:
Editorial on Special Issue “Fatigue and Fracture Behaviour of Additive Manufacturing Mechanical Components”
Authors: Citarella Roberto , De Castro Paulo M. S. T. , Maligno Angelo
Published: March 2020

This Special Issue presents the latest advances in the field of fatigue and fracture performances of additively manufactured mechanical components, including components made of traditional materials (metals, sintered steels, etc.) but undergoing complex loading conditions (multiaxial fatigue and mixed mode fracture). This Special Issue is composed of seven papers covering new insights in structural and material engineering. The advent of additive manufacturing (AM) processes applied to the fabrication of structural components creates the need for design methodologies and structural optimization approaches that take into account the specific characteristics of the process. While AM processes give unprecedented geometrical design freedom, which can result in significant reductions of component weight (e.g., through part count reduction), they have implications in the fatigue and fracture strength due to residual stresses and microstructural features. This is due to stress concentration effects and anisotropy that still need research. The papers of this Special Issue report on numerical simulation and experimental work, or a combination of both. The application of damage and fracture mechanics concepts, the appraisal of stress concentration effects, and the consideration of residual stresses and anisotropic behaviour are tackled for a range of structural applications from biomedical engineering to aerospace components.
Structural Features and Rheological Properties of a Sulfated Xylogalactan-Rich Fraction Isolated from Tunisian Red Seaweed Jania adhaerens
Authors: Hentati Faiez , Delattre Cédric , Gardarin Christine , Desbrières Jacques , Le Cerf Didier , Rihouey Christophe , Michaud Philippe , Abdelkafi Slim , Pierre Guillaume
Published: March 2020

A novel sulfated xylogalactan-rich fraction (JSP for J. adhaerens Sulfated Polysaccharide) was extracted from the red Tunisian seaweed Jania adhaerens. JSP was purified using an alcoholic precipitation process and characterized by Attenuated Total Reflectance-Fourier-transform infrared spectroscopy (ATR-FTIR), high-pressure size exclusion chromatography (HPSEC) with a multi-angle laser light scattering (MALLS), gas chromatography coupled to mass spectrometry (GC-MS) and nuclear magnetic resonance spectroscopy (NMR, 1D and 2D). JSP was then evaluated regarding its physicochemical and rheological properties. Results showed that JSP was mainly composed of an agar-like xylogalactan sharing the general characteristics of corallinans. The structure of JSP was mainly composed of agaran disaccharidic repeating units (→3)-β-d-Galp-(1,4)-α-l-Galp-(1→)n and (→3)-β-d-Galp-(1,4)-3,6-α-l-AnGalp-(1→)n, mainly substituted on O-6 of (1,3)-β-d-Galp residues by β-xylosyl side chains, and less with sulfate or methoxy groups. (1,4)-α-l-Galp residues were also substituted by methoxy and/or sulfate groups in the O-2 and O-3 positions. Mass-average and number-average molecular masses (Mw) and (Mn), intrinsic viscosity ([η]) and hydrodynamic radius (Rh) for JSP were, respectively, 8.0 × 105 g/mol, 1.0 × 105 g/mol, 76 mL/g and 16.8 nm, showing a flexible random coil conformation in solution. The critical overlap concentration C* of JSP was evaluated at 7.5 g/L using the Williamson model. In the semi-diluted regime, JSP solutions displayed a shear-thinning behavior with a great viscoelasticity character influenced by temperature and monovalent salts. The flow characteristics of JSP were described by the Ostwald model.
Experiments and Modeling for Investigation of Oily Sludge Biodegradation in a Wastewater Pond Environment
Authors: Alexander Matthew , Alarwan Najem , Chandrasekaran Maheswari , Sundaram Aishwarya , Milde Tonje , Rasool Saad
Published: March 2020

Historic operating and abandoned refineries frequently contain ponds or lagoons that contain oily sludge from historic wastewater treatment processes and separator sludge disposal activities that occurred prior to the implementation of regulations forbidding such disposal. These oily sludge-containing wastewater ponds represent a long-term liability at older operating refineries or abandoned refinery sites. Dewatering and solidification/stabilization are the most common technologies used to treat these sludges; however, these approaches are labor, equipment, and material-intensive. For sites where the time required to complete treatment is not a high priority, biodegradation treatment may be effective for final site remedy. The objective of this study was to investigate potential improvements in oily material biodegradation using dispersants and petroleum-degrading microbial consortia, along with the modeling of this system. The oil dispersed with mixing or remaining in the bulk aqueous phase with biodegradation was measured using methods from a dispersant effectiveness test. The experimental results indicated that mixing at levels of 200 rpm or higher resulted in positive effects on both the extent of hydrocarbon dispersion (80 to 90% of oil dispersed) and the biodegradation of the oil phase (50 to nearly 100% degraded), while the modeling results, taken along with the experimental results, indicated smaller dispersed phase droplet sizes and promoted more efficient biodegradation.
A Biomechanical Investigation of Athletic Footwear Traction Performance: Integration of Gait Analysis with Computational Simulation
Authors: Shih Kao-Shang , Jhou Shu-Yu , Hsu Wei-Chun , Hsu Ching-Chi , Chen Jun-Wen , Yeh Jui-Chia , Hung Yi-Chun
Published: March 2020

Evaluations are vital to quantify the functionalities of athletic footwear, such as the performance of slip resistance, shock absorption, and rebound. Computational technology has progressed to become a promising solution for accelerating product development time and providing customized products in order to keep up with the competitive contemporary footwear market. In this research, the effects of various tread pattern designs on traction performance in a normal gait were analyzed by employing an approach that integrated computational simulation and gait analysis. A state-of-the-art finite element (FE) model of a shoe was developed by digital sculpting technology. A dynamic plantar pressure distribution was automatically applied to interpret individualized subject conditions. The traction performance and real contact area between the shoe and the ground during the gait could be characterized and predicted. The results suggest that the real contact area and the structure of the outsole tread design influence the traction performance of the shoe in dry conditions. This computational process is more efficient than mechanical tests in terms of both cost and time, and it could bring a noticeable benefit to the footwear industry in the early design phases of product development.
Factor Identification and Prediction for Teen Driver Crash Severity Using Machine Learning: A Case Study
Authors: Lin Ciyun , Wu Dayong , Liu Hongchao , Xia Xueting , Bhattarai Nischal
Published: March 2020

Crashes among young and inexperienced drives are a major safety problem in the United States, especially in an area with large rural road networks, such as West Texas. Rural roads present many unique safety concerns that are not fully explored. This study presents a complete machine leaning pipeline to find the patterns of crashes involved with teen drivers no older than 20 on rural roads in West Texas, identify factors that affect injury levels, and build four machine learning predictive models on crash severity. The analysis indicates that the major causes of teen driver crashes in West Texas are teen drivers who failed to control speed or travel at an unsafe speed when they merged from rural roads to highways or approached intersections. They also failed to yield on the undivided roads with four or more lanes, leading to serious injuries. Road class, speed limit, and the first harmful event are the top three factors affecting crash severity. The predictive machine learning model, based on Label Encoder and XGBoost, seems the best option when considering both accuracy and computational cost. The results of this work should be useful to improve rural teen driver traffic safety in West Texas and other rural areas with similar issues.
Thermal Triggered Release of Menthol from Different Carriers: A Comparative Study
Authors: Wei Min , Song Xuyan , Pan Xi , Li Ran , Chen Chan , Du Xiaodi , Li Junsheng
Published: March 2020

The design of appropriate thermally responsive fragrance carrier systems is of significant importance for the application of fragrance in the food and tobacco industries. In this study, we investigate the potential of sorbitan monostearate and guar gum for the stabilization of menthol under ambient conditions and the thermally-induced release of menthol. Our results show that the sorbitan monostearate carrier could well stabilize the menthol for at least up to 15 days with neglectable menthol loss due to the favorable binding of menthol on the sorbitan monostearate carrier. In addition, rapid and controlled release of menthol could take place at a temperature of 80 °C in the sorbitan monostearate carrier system. As a comparison, guar gum could not stabilize menthol as a result of its poor compatibility. Our results suggest that sorbitan monostearate can be an ideal carrier material for the support of fragrance. In addition, our results also provide a useful guide for the tailored design of thermally responsive fragrance carriers.
Synthesis, Structure, and Thermal Stability of Magnesium Oxychloride 5Mg(OH)2∙MgCl2∙8H2O
Authors: Jiříčková Adéla , Lojka Michal , Lauermannová Anna-Marie , Antončík Filip , Sedmidubský David , Pavlíková Milena , Záleská Martina , Pavlík Zbyšek , Jankovský Ondřej
Published: March 2020

Today, low-energy and low-carbon footprint alternatives to Portland cement are searched because of huge CO2 emissions coming from Portland clinker calcination. Because of some superior properties of magnesium oxychloride cement (MOC) and the lower carbon footprint of its production, MOC became an intensively studied material with high application potential for the design and development of construction products. In this contribution, magnesium oxychloride with stoichiometry 5Mg(OH)2∙MgCl2∙8H2O (Phase 5) was prepared and characterized. The kinetics of formation and the phase composition of the material were determined using X-ray diffraction and consequent Rietveld analysis. The morphology was studied by scanning electron microscopy, and the chemical composition was determined by both energy-dispersive spectroscopy and X-ray fluorescence. Moreover, the simultaneous thermal analysis in combination with mass spectroscopy and Fourier-transform infrared spectroscopy was employed to study the thermal stability. Using mass spectroscopy, we were able to clarify the mechanism of water and hydrochloric acid release, which was not previously reported. The observed structural and chemical changes induced by exposure of studied samples to elevated temperatures were linked with the measured residual macro and micro parameters, such as bulk density, specific density, porosity, water absorption, compressive strength, and pore size distribution. The Phase 5 revealed a needle-like crystalline morphology which formed rapidly and was almost completed after 96 h, resulting in relatively high material strength. The four-day compressive strength of magnesium oxychloride cement was similar to the 28-day compressive strength of Portland cement. The thermal stability of Phase 5 was low as the observed disruptive thermal processes were completed at temperatures lower than 470 °C.
Eliminating the Effect of Uncertainties of Cutting Forces by Fuzzy Controller for Robots in Milling Process
Authors: Phan Khoi Bui , Ha Hai Thanh , Hoang Sinh Vinh
Published: March 2020

This study presents a method of controlling robots based on fuzzy logic to eliminate the effect of uncertainties that are generated by the cutting forces in milling process. The common method to control industrial robots is based on the robot dynamic model and the differential equations of motion to compute the control values. The quantities in the differential equations of the motion of robots are complex and difficult to determine fully and accurately. The interaction forces between the cutting tool and the workpiece are the cutting forces, which are generated during the machining process. It is difficult to calculate the cutting force because it depends on many factors such as material of the machining part, depth of cut, feed rate, etc. This article presents the fuzzy rule system and the selection of the physical value domain of input and output variables of the fuzzy controller. The fuzzy rules are applied in this article to allow us to compute the driving forces based on the errors of input and output signals of the joint positions and velocities, thereby avoiding the calculation of cutting forces. This article shows the simulation results of the fuzzy controller and comparison with the results of the conventional controller when the dynamic model is assumed to be correctly determined. The achieved results are reliable and facilitate the research and application of a fuzzy controller to mechanical processing robots in general and milling machining in particular.
Nonlinear Aeroelastic in-Plane Behavior of Suspension Bridges under Steady Wind Flow
Authors: Di Nino Simona , Luongo Angelo
Published: March 2020

The nonlinear aeroelastic behavior of suspension bridges, undergoing dynamical in-plain instability (galloping), is analyzed. A nonlinear continuous model of bridge is formulated, made of a visco-elastic beam and a parabolic cable, connected each other by axially rigid suspenders, continuously distributed. The structure is loaded by a uniform wind flow which acts normally to the bridge plane. Both external and internal damping are accounted for the structure, according to the Kelvin-Voigt rheological model. The nonlinear aeroelastic effects are evaluated via the quasi-static theory, while structural nonlinearities are not taken into account. First, the free dynamics of the undamped bridge are addressed, and the natural modes determined. Then, the nonlinear equations ruling the dynamics of the aeroelastic system, close to the bifurcation point, are tackled by the Multiple Scale Method. This is directly applied to the partial differential equations, and provides the finite-dimensional bifurcation equations. From these latter, the limit-cycle amplitude and its stability are evaluated as function of the mean wind velocity. A case study of suspension bridge is analyzed.
Evolution of Flow and Streaming in Exponential Variable Cross-Section Resonators
Authors: Feng Heying , Peng Yehui , Bin Guangfu , Shen Yiping
Published: March 2020

A gas-kinetic scheme (GKS) based on an unstructured grid is applied to simulate the evolution of the fluid motions in exponential variable cross-section resonators. The effects of the acoustic field intensity on the oscillatory pressure, velocity, temperature, and flow streaming structure were investigated numerically, and the model was validated. The results demonstrate that the geometry and driving strength are the main factors affecting the final performance of the system. For the quasi-linear and moderate non-linear cases in optimum exponential tube, the periodic generation, evolution, and shedding of vortices in flow fields are associated with the storage and release of energy, which is the transmission mode of the third type of direct current (DC) flow, and its driving mechanism is attributed to the asymmetrical pressure and temperature. Meanwhile, some new physical characteristics were also discovered for the highly non-linear case, e.g., the disorder and unsteadiness of the flow direction accomplished with turbulent flow streaming structures. The secondary flow is manifested as multiscale, irregular and unsteady vortices throughout the tube. The smallest increment of pressure and velocity amplitude occurs concurrently with the biggest increment of temperature amplitude. These evidences suggest that there is an optimal driving strength, even for a good configuration tube, with which the maximum efficiency can be obtained.
Environmental Impact of the Natural Gas Liquefaction Process: An Example from China
Authors: Yuan Xingzhi , Zhang Baosheng , Liang Ruimin , Wang Ruizhi , Sun Yulong
Published: March 2020

Considering its clean and environmental characteristics, natural gas has gradually attracted attention from countries around the world. China’s coal-to-gas project has significantly increased the country’s demand for, and supply of, natural gas. Liquefied natural gas (LNG) has also been gradually promoted, owing to its advantages of easy storage and transportation. However, the natural gas liquefaction process includes multiple phases, and each phase generates substantial industrial pollutants, such as CO2, SO2, and NOx. Despite this, the resulting environmental impacts have not been quantitatively assessed. Therefore, based on the production process of a liquefaction plant in the Shanxi Province, China, in this study, the Life Cycle Assessment (LCA) model was used to analyze the pollutant discharge in the unit’s natural gas liquefaction production process. By collecting data on the production capacity and composition reports of the eight major LNG-producing provinces, such as Henan, Sichuan, Inner Mongolia, Shaanxi, Xinjiang, Shanxi, Ningxia, and Hebei, the total amount of pollutants discharged from the natural gas liquefaction process in China was estimated. Finally, the environmental impact of the natural gas liquefaction process was evaluated according to the results of the environmental impact of pollutants. Our study arrived at the following conclusions: (i) 93.60% of China’s natural gas liquefaction output is concentrated in eight provinces; (ii) in terms of the unit’s LNG production, the Global Warming Potential (GWP), Acidification Potential (AP), Eutrophication Potential (EP), Photochemical Ozone Creation Potential (POCP) and Dust Potential (DP) proportions of each province explained the gas composition of LNG production gas sources in each province; (iii) the environmental problems caused by natural gas liquefaction were different in each provinces. In addition, we suggested relevant policy recommendations. First, the formulation of LNG-related policies should consider environmental pollution produced during the liquefaction stage. Second, if the problem of pollutant discharge in the liquefaction of natural gas is properly solved, it will not only reduce environmental pollution, but also generate additional income. Third, different provinces should optimize production technology based on the different gas qualities.
The Contribution of Storage Medium and Membranes in the Microwave Dielectric Response of Packed Red Blood Cells Suspension
Authors: Latypova Larisa , Barshtein Gregory , Arbell Dan , Feldman Yuri
Published: March 2020

During cold storage, packed red blood cells (PRBCs) undergo slow detrimental changes that are collectively termed storage lesion. The aging of the cells causes alterations in the composition of the storage-medium in the PRBC unit. In this paper, we present the comparison of the dielectric response of water in the primary (fresh) storage medium (citrate phosphate dextrose adenine solution, CPDA-1) versus the storage medium from three expired units of PRBCs. Dielectric response of the water molecules has been characterized by dielectric spectroscopy technique in the microwave frequency band (0.5–40 GHz). The dominant phenomenon is the significant increase of the dielectric strength and decrease the relaxation time τ for the samples of the stored medium in comparison with the fresh medium CPDA-1. Furthermore, we demonstrated that removing the ghosts from PRBC hemolysate did not cause the alteration of the dielectric spectrum of water. Thus, the contribution associated with water located near the cell membrane can be neglected in microwave dielectric measurements.
Aerodynamic Characteristics of Different Airfoils under Varied Turbulence Intensities at Low Reynolds Numbers
Authors: Zhang Yang , Zhou Zhou , Wang Kelei , Li Xu
Published: March 2020

A numerical study was conducted on the influence of turbulence intensity and Reynolds number on the mean topology and transition characteristics of flow separation to provide better understanding of the unsteady jet flow of turboelectric distributed propulsion (TeDP) aircraft. By solving unsteady Reynolds averaged Navier-Stokes (URANS) equation based on C-type structural mesh and γ - Re ˜ θ t transition model, the aerodynamic characteristics of the NACA0012 airfoil at different turbulence intensities was calculated and compared with the experimental results, which verifies the reliability of the numerical method. Then, the effects of varied low Reynolds numbers and turbulence intensities on the aerodynamic performance of NACA0012 and SD7037 were investigated. The results show that higher turbulence intensity or Reynolds number leads to more stable airfoil aerodynamic performance, larger stalling angle, and earlier transition with a different mechanism. The generation and evolution of the laminar separation bubble (LSB) are closely related to Reynolds number, and it would change the effective shape of the airfoil, having a big influence on the airfoil’s aerodynamic characteristics. Compared with the symmetrical airfoil, the low-Reynolds-number airfoil can delay the occurrence of flow separation and produce more lift in the same conditions, which provides guidance for further airfoil design under TeDP jet flow.
Five-Axis Freeform Surface Color Printing Technology Based on Offset Curve Path Planning Method
Authors: Shen Hongyao , Liu Bing , Liu Senxin , Fu Jianzhong
Published: March 2020

Great progress has been made in 2D color printing with inkjet technology, and mature related products have come out, but there still exists great developmental space in 3D color printing. Therefore, a new path planning method based on the offset curve for 3D inkjet technology is proposed in this paper. Offset curves are generated on a freeform surface with geodesic equidistance, and then points for color printing are generated along the offset curves. In this paper, the principle of color printing technology with a 5-axis platform and the offset curve path planning (OCPP) method are presented. In addition, comparisons between the OCPP and adaptive filling algorithm based on the section method (AFSM) have been implemented. The OCPP significantly increased the rate of the theoretical filling area from 0.89 to 0.99 on a freeform surface.
Diversity Maintenance for Efficient Robot Path Planning
Authors: Ćurković Petar , Čehulić Lovro
Published: March 2020

Path planning is present in many areas, such as robotics, video games, and unmanned autonomous vehicles. In the case of robots, it is a primary low-level prerequisite for the successful execution of high-level tasks. It is a known and difficult problem to solve, especially in terms of finding optimal paths for robots working in complex environments. Recently, population-based methods for multi-objective optimization, i.e., swarm and evolutionary algorithms successfully perform on different path planning problems. Knowing the nature of the problem is hard for optimization algorithms, it is expected that population-based algorithms might benefit from some kind of diversity maintenance implementation. However, advantages and potential traps of implementing specific diversity maintenance methods into the evolutionary path planner have not been clearly spelled out and experimentally demonstrated. In this paper, we fill this gap and compare three diversity maintenance methods and their impact on the evolutionary planner for problems of different complexity. Crowding, fitness sharing, and novelty search are tailored to fit specific problems, implemented, and tested for two scenarios: mobile robot operating in a 2D maze, and 3 degrees of freedom (DOF) robot operating in a 3D environment including obstacles. Results indicate that the novelty search outperforms the other two methods for problem domains of higher complexity.
Source Separation Using Dilated Time-Frequency DenseNet for Music Identification in Broadcast Contents
Authors: Heo Woon-Haeng , Kim Hyemi , Kwon Oh-Wook
Published: March 2020

We propose a source separation architecture using dilated time-frequency DenseNet for background music identification of broadcast content. We apply source separation techniques to the mixed signals of music and speech. For the source separation purpose, we propose a new architecture to add a time-frequency dilated convolution to the conventional DenseNet in order to effectively increase the receptive field in the source separation scheme. In addition, we apply different convolutions to each frequency band of the spectrogram in order to reflect the different frequency characteristics of the low- and high-frequency bands. To verify the performance of the proposed architecture, we perform singing-voice separation and music-identification experiments. As a result, we confirm that the proposed architecture produces the best performance in both experiments because it uses the dilated convolution to reflect wide contextual information.
Adaptive Sliding Mode PID Control for Underwater Manipulator Based on Legendre Polynomial Function Approximation and Its Experimental Evaluation
Authors: Yang Chao , Yao Feng , Zhang Mingjun , Zhang Zhiqiang , Wu Zhenzhen , Dan Peijian
Published: March 2020

The joint control problem of the underwater manipulator is addressed in this paper, under the influence of uncertainty factors such as model uncertainty, external disturbance, and manipulator joint lag. In general, for the uncertainty factors, it is usually approximated online, but it is difficult to select a reasonable value for the approximation error boundary, too conservative estimated values would cause chattering problem easily. And the influence of joint lag on the manipulator control should be considered in actual work. Unlike most previous control method, in this paper, the function approximation technique (FAT), which uses the Legendre polynomial, is adopted to approximate the uncertainty factors online. Then, based on the proportion integral differential (PID) sliding manifold with the integral and differential of tracking error, a sliding model PID controller is designed to speed up the response and reduce the effects of joint lag. For the error boundary, the adaptive law is proposed, and it will reduce chattering of the control quantity under the steady state of the system. It was proved that the joint error of the control system is uniformly asymptotic convergence through the stability analysis. Finally, the effectiveness of the proposed approach is demonstrated with pool comparison experiments of the underwater manipulator installed in the autonomous underwater vehicles (AUVs).
Cognitive Ergonomics Evaluation Assisted by an Intelligent Emotion Recognition Technique
Authors: Rodriguez Aguiñaga Adrian , Realyvásquez-Vargas Arturo , López R. Miguel Ángel , Quezada Angeles
Published: March 2020

The study of the cognitive effects caused by work activities are vital to ensure the well-being of a worker, and this work presents a strategy to analyze these effects while they are carrying out their activities. Our proposal is based on the implementation of pattern recognition techniques to identify emotions in facial expressions and correlate them to a proposed situation awareness model that measures the levels of comfort and mental stability of a worker and proposes corrective actions. We present the experimental results that could not be collected through traditional techniques since we carry out a continuous and uninterrupted assessment of the cognitive situation of a worker.
Removal of Cu(II) from Aqueous Solutions Using Amine-Doped Polyacrylonitrile Fibers
Authors: Aung Kay Thwe , Hong Seung-Hee , Park Seong-Jik , Lee Chang-Gu
Published: March 2020

Polyacrylonitrile (PAN) fibers were prepared via electrospinning and were modified with diethylenetriamine (DETA) to fabricate surface-modified PAN fibers. The surface-modified PAN fibers were used to evaluate their adsorption capacity for the removal of Cu(II) from aqueous solutions. Batch adsorption experiments were performed to examine the effects of the modification process, initial concentration, initial pH, and adsorbent dose on the adsorption of Cu(II). Kinetic analysis revealed that the experimental data fitted the pseudo-second-order kinetic model better than the pseudo-first-order model. Adsorption equilibrium studies were conducted using the Freundlich and Langmuir isotherm models, and the findings indicated that the PAN fibers modified with 85% DETA presented the highest adsorption capacity for Cu(II) of all analyzed samples. Moreover, the results revealed that the Freundlich model was more appropriate than the Langmuir one for describing the adsorption of Cu(II) onto the modified fibers at various initial Cu(II) concentrations. The maximum adsorption capacity was determined to be 87.77 mg/g at pH 4, and the percent removal of Cu(II) increased as the amount of adsorbent increased. Furthermore, the surface-modified PAN fibers could be easily regenerated using NaOH solution. Therefore, surface-modified PAN fibers could be used as adsorbents for the removal of Cu(II) from aqueous solutions.
Passively Sampled Ambient Hydrocarbon Abundances in a Texas Oil Patch
Authors: Sablan Olivia M. , Schade Gunnar W. , Holliman Joel
Published: March 2020

The United States has experienced exceptional growth in oil production via unconventional extraction for over a decade. This boom has led to an increase in hydrocarbon emissions to the atmosphere. With Texas as the leading contributor to growing oil production, it is important to assess the effects the boom has had on the environment and communities at local and regional levels. We conducted a pilot study to investigate the use of passive samplers for evaluating potential off-site risk from hydrocarbon emissions in a relatively low production activity area of the Texas Eagle Ford shale. Emissions from production sites include benzene, a hazardous air pollutant and known carcinogen. Passive hydrocarbon sampling devices (Radiello samplers) were used to monitor hydrocarbon levels on a rural property near a production site with an occasional flare for one year. Selected hydrocarbons were analyzed using thermal desorption and gas chromatography with flame ionization detection. Benzene concentrations were found to be correlated with changes in season, with higher abundance in the winter months. Benzene levels at this site were similar or higher than those observed in urban areas, away from shale oil and gas production. Increased benzene concentrations were distinguished when winds advected hydrocarbons from the production site, suggesting that oil and gas site emissions have a greater impact on the local community when winds advect them towards those living downwind; however, hydrocarbon levels in this low production area never exceeded state air monitoring comparison standards.
Neural Modulation of the Primary Auditory Cortex by Intracortical Microstimulation with a Bio-Inspired Electronic System
Authors: Bianco Maria Giovanna , Pullano Salvatore Andrea , Citraro Rita , Russo Emilio , De Sarro Giovambattista , de Villers Sidani Etienne , Fiorillo Antonino S.
Published: March 2020

Nowadays, the majority of the progress in the development of implantable neuroprostheses has been achieved by improving the knowledge of brain functions so as to restore sensorial impairments. Intracortical microstimulation (ICMS) is a widely used technique to investigate site-specific cortical responses to electrical stimuli. Herein, we investigated the neural modulation induced in the primary auditory cortex (A1) by an acousto-electric transduction of ultrasonic signals using a bio-inspired intracortical microstimulator. The developed electronic system emulates the transduction of ultrasound signals in the cochlea, providing bio-inspired electrical stimuli. Firstly, we identified the receptive fields in the primary auditory cortex devoted to encoding ultrasonic waves at different frequencies, mapping each area with neurophysiological patterns. Subsequently, the activity elicited by bio-inspired ICMS in the previously identified areas, bypassing the sense organ, was investigated. The observed evoked response by microstimulation resulted as highly specific to the stimuli, and the spatiotemporal dynamics of neural oscillatory activity in the alpha, beta, and gamma waves were related to the stimuli preferred by the neurons at the stimulated site. The alpha waves modulated cortical excitability only during the activation of the specific tonotopic neuronal populations, inhibiting neural responses in unrelated areas. Greater neuronal activity in the posterior area of A1 was observed in the beta band, whereas a gamma rhythm was induced in the anterior A1. The results evidence that the proposed bio-inspired acousto-electric ICMS triggers high-frequency oscillations, encoding information about the stimulation sites and involving a large-scale integration in the brain.
Eco-Friendly Bioemulsifier Production by Mucor circinelloides UCP0001 Isolated from Mangrove Sediments Using Renewable Substrates for Environmental Applications
Authors: Marques Nathália S. A. A. , Silva Israel G. Sales da , Cavalcanti Davi L. , Maia Patrícia C. S. V. , Santos Vanessa P. , Andrade Rosileide F. S. , Campos-Takaki Galba M.
Published: March 2020

The successful production of a biosurfactant is dependent on the development of processes using low cost raw materials. In the present work, an economically attractive medium composed of corn steep liquor and waste cooking oil was formulated to maximize the production of bioemulsifier by Mucor circinelloides UCP0001. A central rotational composite design was applied to statistical validation of the production. The emulsifying properties, stability under extreme conditions, its toxicity character, and the characterization of the bioemulsifier were determined. The best condition for biomolecule synthesis occurred in the assay 2 containing 4% of corn steep liquor and 3% waste soybean oil and exhibited 100% emulsification index for canola oil and petroleum, as well as excellent emulsifying activity for canola oil and burned engine oil. The nutritional factors studied showed statistical relevance, since all linear, quadratic effects and their interactions were significant. The bioemulsifier showed 2.69 g/L yield and the chemical character of the molecule structure was identified by FT-IR (Fourier Transform Infrared) spectroscopy. The bioemulsifier showed no toxicity to Artemia salina and Chlorella vulgaris. Stable emulsions were obtained under extreme conditions of temperature, pH, and salinity. These findings contribute to understanding of the relationship between production, physical properties, chemical composition, and stability of bioemulsifier for their potential applications in biotechnology, such as bioremediation of hydrocarbon-contaminated soil and water.
Ginseng Gintonin Attenuates Lead-Induced Rat Cerebellar Impairments during Gestation and Lactation
Authors: Nam Sung Min , Choi Sun-Hye , Cho Hee-Jung , Seo Jin Seok , Choi Minsuk , Nahm Sang-Soep , Chang Byung-Joon , Nah Seung-Yeol
Published: March 2020

Gintonin, a novel ginseng-derived lysophosphatidic acid receptor ligand, improves brain functions and protects neurons from oxidative stress. However, little is known about the effects of gintonin against Pb-induced brain maldevelopment. We investigated the protective effects of gintonin on the developing cerebellum after prenatal and postnatal Pb exposure. Pregnant female rats were randomly divided into three groups: control, Pb (0.3% Pb acetate in drinking water), and Pb plus gintonin (100 mg/kg, p.o.). Blood Pb was increased in dams and pups; gintonin treatment significantly decreased blood Pb. On postnatal day 21, the number of degenerating Purkinje cells was remarkably increased while the number of calbindin-, GAD67-, NMDAR1-, LPAR1-immunoreactive intact Purkinje cells, and GABA transporter 1-immunoreactive pinceau structures were significantly reduced in Pb-exposed offspring. Following Pb exposure, gintonin ameliorated cerebellar degenerative effects, restored increased pro-apoptotic Bax, and decreased anti-apoptotic Bcl2. Gintonin treatment attenuated Pb-induced accumulation of oxidative stress (Nrf2 and Mn-SOD) and inflammation (IL-1β and TNFα,), restoring the decreased cerebellar BDNF and Sirt1. Gintonin ameliorated Pb-induced impairment of myelin basic protein-immunoreactive myelinated fibers of Purkinje cells. Gintonin attenuated Pb-induced locomotor dysfunctions. The present study revealed the ameliorating effects of gintonin against Pb, suggesting the potential use of gintonin as a preventive agent in Pb poisoning during pregnancy and lactation.
Altered Plasma Acylcarnitines and Amino Acids Profile in Spinocerebellar Ataxia Type 7
Authors: Nambo-Venegas Rafael , Valdez-Vargas Claudia , Cisneros Bulmaro , Palacios-González Berenice , Vela-Amieva Marcela , Ibarra-González Isabel , Cerecedo-Zapata César M. , Martínez-Cruz Emilio , Cortés Hernán , Reyes-Grajeda Juan P. , Magaña Jonathan J.
Published: March 2020

Spinocerebellar ataxia type 7 (SCA7), a neurodegenerative disease characterized by cerebellar ataxia and retinal degeneration, is caused by an abnormal CAG repeat expansion in the ATXN7 gene coding region. The onset and severity of SCA7 are highly variable between patients, thus identification of sensitive biomarkers that accurately diagnose the disease and monitoring its progression are needed. With the aim of identified SCA7-specific metabolites with clinical relevance, we report for the first time, to the best of our knowledge, a metabolomics profiling of circulating acylcarnitines and amino acids in SCA7 patients. We identified 21 metabolites with altered levels in SCA7 patients and determined two different sets of metabolites with diagnostic power. The first signature of metabolites (Valine, Leucine, and Tyrosine) has the ability to discriminate between SCA7 patients and healthy controls, while the second one (Methionine, 3-hydroxytetradecanoyl-carnitine, and 3-hydroxyoctadecanoyl-carnitine) possess the capability to differentiate between early-onset and adult-onset patients, as shown by the multivariate model and ROC analyses. Furthermore, enrichment analyses of metabolic pathways suggest alterations in mitochondrial function, energy metabolism, and fatty acid beta-oxidation in SCA7 patients. In summary, circulating SCA7-specific metabolites identified in this study could serve as effective predictors of SCA7 progression in the clinics, as they are sampled in accessible biofluid and assessed by a relatively simple biochemical assay.
Targeting α-Synuclein for PD Therapeutics: A Pursuit on All Fronts
Authors: Teil Margaux , Arotcarena Marie-Laure , Faggiani Emilie , Laferriere Florent , Bezard Erwan , Dehay Benjamin
Published: March 2020

Parkinson’s Disease (PD) is characterized both by the loss of dopaminergic neurons in the substantia nigra and the presence of cytoplasmic inclusions called Lewy Bodies. These Lewy Bodies contain the aggregated α-synuclein (α-syn) protein, which has been shown to be able to propagate from cell to cell and throughout different regions in the brain. Due to its central role in the pathology and the lack of a curative treatment for PD, an increasing number of studies have aimed at targeting this protein for therapeutics. Here, we reviewed and discussed the many different approaches that have been studied to inhibit α-syn accumulation via direct and indirect targeting. These analyses have led to the generation of multiple clinical trials that are either completed or currently active. These clinical trials and the current preclinical studies must still face obstacles ahead, but give hope of finding a therapy for PD with time.
Interplay between Endoplasmic Reticulum (ER) Stress and Autophagy Induces Mutant p53H273 Degradation
Authors: Garufi Alessia , Federici Giulia , Gilardini Montani Maria Saveria , Crispini Alessandra , Cirone Mara , D’Orazi Gabriella
Published: March 2020

The unfolded protein response (UPR) is an adaptive response to intrinsic and external stressors, and it is mainly activated by the accumulation of misfolded proteins at the endoplasmic reticulum (ER) lumen producing ER stress. The UPR signaling network is interconnected with autophagy, the proteolytic machinery specifically devoted to clearing misfolded proteins in order to survive bioenergetic stress and/or induce cell death. Oncosuppressor TP53 may undergo inactivation following missense mutations within the DNA-binding domain (DBD), and mutant p53 (mutp53) proteins may acquire a misfolded conformation, often due to the loss of the DBD-bound zinc ion, leading to accumulation of hyperstable mutp53 proteins that correlates with more aggressive tumors, resistance to therapies, and poorer outcomes. We previously showed that zinc supplementation induces mutp53 protein degradation by autophagy. Here, we show that mutp53 (i.e., Arg273) degradation following zinc supplementation is correlated with activation of ER stress and of the IRE1α/XBPI arm of the UPR. ER stress inhibition with chemical chaperone 4-phenyl butyrate (PBA) impaired mutp53 downregulation, which is similar to IRE1α/XBPI specific inhibition, reducing cancer cell death. Knockdown of mutp53 failed to induce UPR/autophagy activation indicating that the effect of zinc on mutp53 folding was likely the key event occurring in ER stress activation. Recently discovered small molecules targeting components of the UPR show promise as a novel anticancer therapeutic intervention. However, our findings showing UPR activation during mutp53 degradation indicate that caution is necessary in the design of therapies that inhibit UPR components.
Increased Resting State Triple Network Functional Connectivity in Undergraduate Problematic Cannabis Users: A Preliminary EEG Coherence Study
Authors: Imperatori Claudio , Massullo Chiara , Carbone Giuseppe Alessio , Panno Angelo , Giacchini Marta , Capriotti Cristina , Lucarini Elisa , Ramella Zampa Benedetta , Murillo-Rodríguez Eric , Machado Sérgio , Farina Benedetto
Published: March 2020

An increasing body of experimental data have suggested that aberrant functional interactions between large-scale networks may be the most plausible explanation of psychopathology across multiple mental disorders, including substance-related and addictive disorders. In the current research, we have investigated the association between problematic cannabis use (PCU) and triple-network electroencephalographic (EEG) functional connectivity. Twelve participants with PCU and 24 non-PCU participants were included in the study. EEG recordings were performed during resting state (RS). The exact Low-Resolution Electromagnetic Tomography software (eLORETA) was used for all EEG analyses. Compared to non-PCU, PCU participants showed an increased delta connectivity between the salience network (SN) and central executive network (CEN), specifically, between the dorsal anterior cingulate cortex and right posterior parietal cortex. The strength of delta connectivity between the SN and CEN was positively and significantly correlated with higher problematic patterns of cannabis use after controlling for age, sex, educational level, tobacco use, problematic alcohol use, and general psychopathology (rp = 0.40, p = 0.030). Taken together, our results show that individuals with PCU could be characterized by a specific dysfunctional interaction between the SN and CEN during RS, which might reflect the neurophysiological underpinnings of attentional and emotional processes of cannabis-related thoughts, memories, and craving.
Urban Morphology and Outdoor Microclimate around the “Shophouse” Dwellings in Ho Chi Minh City, Vietnam
Authors: Dang Hung , Pitts Adrian
Published: March 2020

The underestimation of population growth has resulted in the disruptive and uncontrolled expansion of settlements in Ho Chi Minh City (HCMC). The outcome is a complicated mix of new spontaneous dwelling areas featuring a number of distinct urban morphologies. Previous studies have shown the impacts of urban morphologies on comfort levels in outdoor environments. The paper examines the correlation of microclimatic conditions and constituents that create the urban spatial form of residential neighbourhoods, particularly around ‘shophouse’ buildings. Understanding that relationship is significant for improving the future planning and design of residential zones and the creation of a pleasant external environment. Seven urban dwelling patterns were studied. Thermal variables were measured on-site over a summer season, while meteorological data were recorded. Additionally, numerical studies of the microclimate around two sample sites showed variations owing to different urban contexts. During summer, the outdoor conditions for the types surveyed ranged from 29.5 to 38.0 °C air temperature, 41% to 79% humidity, and 0.1 to 0.9 m/s airspeed at the occupied level. Environmental variations averaged 1.5 °C, 7% relative humidity, and 0.3 m/s between the urban geometries. Occupant thermal satisfaction was found around formally planned dwelling blocks, while compact neighbourhoods were characterised by cooler temperatures, but poor airflow and daylight. The outcomes are significant for optimising urban and building design.
Current Role of Total Laryngectomy in the Era of Organ Preservation
Authors: Bozec Alexandre , Culié Dorian , Poissonnet Gilles , Dassonville Olivier
Published: March 2020

In this article, we aimed to discuss the role of total laryngectomy (TL) in the management of patients with larynx cancer (LC) in the era of organ preservation. Before the 1990s, TL followed by radiotherapy (RT) was the standard treatment for patients with locally advanced LC. Over the last 30 years, various types of larynx preservation (LP) programs associating induction or concurrent chemotherapy (CT) with RT have been developed, with the aim of treating locally advanced LC patients while preserving the larynx and its functions. Overall, more than two-thirds of patients included in a LP program will not require total laryngectomy (TL) and will preserve a functional larynx. However, despite these advances, the larynx is the only tumor site in the upper aero-digestive tract for which prognosis has not improved during recent decades. Indeed, none of these LP protocols have shown any survival advantage compared to primary radical surgery, and it appears that certain LC patients do not benefit from an LP program. This is the case for patients with T4a LC (extra-laryngeal tumor extension through the thyroid cartilage) or with poor pretreatment laryngeal function and for whom primary TL is still the preferred therapeutic option. Moreover, TL is the standard salvage therapy for patients with recurrent tumor after an LP protocol.