bluuebunny/crossref_metadata_2025 huggingface dataset:
Alleviation of Oxidative Stress in Dental Pulp Cells Following 4-Hexylresorcinol Administration in a Rat Model
Authors: Chang Jun-Ho , Kim Dae-Won , Kim Seong-Gon , Kim Tae-Woo
Published: April 2021

Damaged dental pulp undergoes oxidative stress and 4-hexylresorcinol (4HR) is a well-known antioxidant. In this study, we aimed to evaluate the therapeutic effects of a 4HR ointment on damaged dental pulp. Pulp cells from rat mandibular incisor were cultured and treated with 4HR or resveratrol (1–100 μM). These treatments (10–100 μM) exerted a protective effect during subsequent hydrogen peroxide treatments. The total antioxidant capacity and glutathione peroxidase activity were significantly increased following 4HR or resveratrol treatment (p < 0.05), while the expression levels of TNF-α and IL1β were decreased following the exposure to 4HR pre-treatment in an in vitro model. Additionally, the application of 4HR ointment in an exposed dental pulp model significantly reduced the expression of TNF-α and IL1β (p < 0.05). Conclusively, 4HR exerted protective effects against oxidative stress in dental pulp tissues through downregulating TNF-α and IL1β.
Seismic Velocity Characterisation of Geothermal Reservoir Rocks for CO2 Storage Performance Assessment
Authors: Janssen Martijn T. G. , Barnhoorn Auke , Draganov Deyan , Wolf Karl-Heinz A. A. , Durucan Sevket
Published: April 2021

As part of a seismic monitoring project in a geothermal field, where the feasibility of re-injection and storage of produced CO2 is being investigated, a P- and S-wave seismic velocity characterisation study was carried out. The effect of axial (up to 95 MPa) and radial (up to 60 MPa) stress on the seismic velocity was studied in the laboratory for a broad range of dry sedimentary and metamorphic rocks that make up the Kızıldere geothermal system in Turkey. Thin section texture analyses conducted on the main reservoir formations, i.e., marble and calcschist, confirm the importance of the presence of fractures in the reservoir: 2D permeability increases roughly by a factor 10 when fractures are present. Controlled acoustic-assisted unconfined and confined compressive strength experiments revealed the stress-dependence of seismic velocities related to the several rock formations. For each test performed, a sharp increase in velocity was observed at relatively low absolute stress levels, as a result of the closure of microcracks, yielding an increased mineral-to-mineral contact area, thus velocity. A change in radial stress appeared to have a negligible impact on the resulting P-wave velocity, as long as it exceeds atmospheric pressure. The bulk of the rock formations studied showed reducing P-wave velocities as function of increasing temperature due to thermal expansion of the constituting minerals. This effect was most profound for the marble and calcschist samples investigated.
Evaluation and Validation of Viscous Oil Cavitation Model Used in Torque Converter
Authors: Guo Meng , Liu Cheng , Yan Qingdong , Ke Zhifang , Wei Wei , Li Juan
Published: April 2021

Hydraulic torque converter is widely used in transmission units as it is able to provide variable speed and torque ratio, isolate vibration, and absorb shock. The pursuit of a highly packed power unit requires a high capacity/speed torque converter, consequently resulting in a higher risk for cavitation and severe performance degradation, noise, vibration, and even failure. Existing cavitation models generally focus on water, and the empirical parameters are not suitable for the cavitation prediction of torque converter which utilizes high viscosity oil as its working medium. This paper focused on the influence of parameters on the performance and cavitation characteristics of torque converter. A full flow passage geometry and different computational fluid dynamics (CFD) models with cavitation were developed to predict torque converter fluid behavior by resolving Reynolds-averaged Navier–Stokes equations using finite volume method (FVM). The numerical results indicated that nuclei volume fraction, vaporization coefficient, mean nucleation site radius, and maximum density ratio have great influences on the cavitation behavior. These parameters altered the degree of cavitation and the pressure distribution on the surface of stator blades, and affected the stall performance such as stall capacity factor and torque ratio. The cavitation model was then modified to improve calculation accuracy. The test results showed that the prediction error under stall operating condition was decreased from 6.7% to 2%. This study provides insight on the influences of the empirical parameters on both internal cavitation behavior as well as overall hydrodynamic performance.
Strengthening Design of RC Columns with Direct Fastening Steel Jackets
Authors: Shan Zhiwei , Chen Lijie , Liang Kun , Su Ray Kai Leung , Xu Zhaodong
Published: April 2021

For non-seismically designed columns with insufficient strength and flexural stiffness, intense inter-story drift can be incurred during a strong earthquake event, potentially leading to the collapse of the entire building. Existing strengthening methods mainly focus on enhancing axial or flexural strength but not the flexural stiffness of columns. In response, a novel direct fastening steel jackets that can increase both flexural strength and stiffness is introduced. This novel strengthening method features straightforward installation and swift strengthening as direct fastening is used to connect steel plates together to form a steel jacketed column. This new connection method can quickly and stably connect two steel components together by driving high strength fasteners into them. In this paper, the design procedure of RC columns strengthened with this novel strengthening method is originally proposed, which includes five steps: (1) estimating lateral load capacity of damaged RC columns; (2) determining connection spacing of steel jacket; (3) estimating the lateral load capacity of strengthened RC column; (4) evaluating the axial load ratio (ALR) of strengthened RC columns; and (5) estimating effective stiffness of strengthened RC columns. Lastly, an example is presented to illustrate the application of the proposed design procedure.
Poly(vinyl alcohol)/Gelatin Scaffolds Allow Regeneration of Nasal Tissues
Authors: D’Alessandro Delfo , Moscato Stefania , Fusco Alessandra , De la Ossa Jose Gustavo , D’Acunto Mario , Trombi Luisa , Feula Marta , Serino Lorenzo Pio , Donnarumma Giovanna , Petrini Mario , Berrettini Stefano , Danti Serena
Published: April 2021

Need for regeneration and repair of nasal tissues occurs as a consequence of several pathologies affecting the nose, including, but not limited to infective diseases, traumas and tumor resections. A platform for nasal tissue regeneration was set up using poly(vinyl alcohol)/gelatin sponges with 20%–30% (w/w) gelatin content to be used as scaffolds, for their intrinsic hydrophilic, cell adhesive and shape recovery properties. We propose mesodermal progenitor cells (MPCs) isolated from the bone marrow as a unique stem cell source for obtaining different connective tissues of the nose, including vascular tissue. Finally, epithelial cell immune response to these scaffolds was assessed in vitro in an environment containing inflammatory molecules. The results showed that mesenchymal stromal cells (MSCs) deriving from MPCs could be used to differentiate into cartilage and fibrous tissue; whereas, in combination with endothelial cells still deriving from MPCs, into pre-vascularized bone. Finally, the scaffold did not significantly alter the epithelial cell response to inflammatory insults derived from interaction with bacterial molecules.
The Investigation on the Flow Distortion Effect of Header to Guarantee the Measurement Accuracy of the Ultrasonic Gas Flowmeter
Authors: Chen Wenlin , Wu Jianjun , Li Chunhui
Published: April 2021

The quantification of the flow distortion effect on the measurement accuracy of the ultrasonic gas flowmeter downstream of the header is important but an area that has been of less concern in the research. By experiments and computational fluid dynamics (CFD), the influence of flow field distortion was studied. Experimental results under three different installation conditions showed that when there was flow field distortion downstream of the header, the measurement results of the gas ultrasonic flowmeter were 1% higher than those when there was no distortion, while a flow conditioner could effectively eliminate flow field distortion. Based on the experimental tests, the flow field distribution was analyzed with CFD, which showed that the flow field distortion effect generated by the header had a significant influence on the parameter of nonconforming Profile factor, while the parameters of Symmetry and Cross-flow could be obviously eliminated by the double-cross-section designing.
The Stability of Vitamin A from Different Sources in Vitamin Premixes and Vitamin-Trace Mineral Premixes
Authors: Yang Pan , Wang Huakai , Li Longxian , Zhang Nan , Ma Yongxi
Published: April 2021

This study was conducted to investigate the stability of five commercial vitamin A products in vitamin premixes and vitamin-trace mineral premixes. The five commercial products used were: Xinhecheng, Zhejiang medicine, Kingdomway, DSM, and BASF. The vitamin A products were stored in three vitamin premixes (for suckling, weanling, and finishing pigs) or in vitamin-trace mineral (VTM) premixes (for suckling, weanling, and finishing pigs). Vitamin premixes were stored in an environmentally controlled chamber set at 25 °C and 60% humidity. The VTM premixes were stored at room temperature (approximately 22 °C). Sampling was performed on d 0, 90, 180, 270, and 360. Stability was reported as the residual vitamin A activity (% of initial) at each sampling point. For the stability of vitamin premixes, all interactive and main effects of storage time and vitamin A product were not significant. For the stability of VTM premixes, there was no significant interaction effects between storage time, vitamin A product and main effect of vitamin A product, but the main effect of storage time was significant (p < 0.01). In conclusion, a longer storage time reduced vitamin A activity in VTM premixes but there was no difference in the stability of commercially available vitamin A.
Modelling and Stability Analysis of Articulated Vehicles
Authors: Lei Tianlong , Wang Jixin , Yao Zongwei
Published: April 2021

This study constructs a nonlinear dynamic model of articulated vehicles and a model of hydraulic steering system. The equations of state required for nonlinear vehicle dynamics models, stability analysis models, and corresponding eigenvalue analysis are obtained by constructing Newtonian mechanical equilibrium equations. The objective and subjective causes of the snake oscillation and relevant indicators for evaluating snake instability are analysed using several vehicle state parameters. The influencing factors of vehicle stability and specific action mechanism of the corresponding factors are analysed by combining the eigenvalue method with multiple vehicle state parameters. The centre of mass position and hydraulic system have a more substantial influence on the stability of vehicles than the other parameters. Vehicles can be in a complex state of snaking and deviating. Different eigenvalues have varying effects on different forms of instability. The critical velocity of the linear stability analysis model obtained through the eigenvalue method is relatively lower than the critical velocity of the nonlinear model.
Numerical Modeling of Nondestructive Testing of Various Conductive Objects inside Metal Enclosures Using ELF/VLF Magnetic Fields
Authors: Kim Hoyoung , Harid Vijay
Published: April 2021

Nondestructive evaluation of various conductive objects through metal enclosures is investigated by using ELF/VLF magnetic induction fields in detailed simulations. ELF/VLF magnetic fields (<30 kHz) have a unique ability to penetrate highly conductive or permeable shields. Using a magnetic dipole source antenna, objects hidden inside a metal enclosure are imaged via examining distortions to the field outside the enclosure. The field distortion is parametrically studied by varying the size, conductivity, and permeability of the hidden objects. Furthermore, the importance of the conductivity of the enclosure itself is investigated using both low (106 S/m) and high (108 S/m) conductivity metallic shields. It is shown that the responses are quite sensitive to the object and shield parameters; both qualitative and quantitative properties of the field distortions are described in detail. The simulation results suggest that properties of hidden conductive or permeable objects, over a relatively wide range of parameters (both geometry and material), can be inferred nondestructively using ELF/VLF magnetic induction fields.
Detecting Change between Urban Road Environments along a Route Based on Static Road Object Occurrences
Authors: Fazekas Zoltán , Gerencsér László , Gáspár Péter
Published: April 2021

For over a decade, urban road environment detection has been a target of intensive research. The topic is relevant for the design and implementation of advanced driver assistance systems. Typically, embedded systems are deployed in these for the operation. The environments can be categorized into road environment-types. Abrupt transitions between these pose a traffic safety risk. Road environment-type transitions along a route manifest themselves also in changes in the distribution of traffic signs and other road objects. Can the placement and the detection of traffic signs be modelled jointly with an easy-to-handle stochastic point process, e.g., an inhomogeneous marked Poisson process? Does this model lend itself for real-time application, e.g., via analysis of a log generated by a traffic sign detection and recognition system? How can the chosen change detector help in mitigating the traffic safety risk? A change detection method frequently used for Poisson processes is the cumulative sum (CUSUM) method. Herein, this method is tailored to the specific stochastic model and tested on realistic logs. The use of several change detectors is also considered. Results indicate that a traffic sign-based road environment-type change detection is feasible, though it is not suitable for an immediate intervention.
Effect of Steaming on Vitamin Retention in Tubers from Eight Cultivars of Potato (Solanum tuberosum L.)
Authors: Liu Ji’an , Ren Ying , Wang Guiping , Sun Hui , Zhu Yongyong , Wang Lei , Zhang Chunyi , Zhang Lan , Jiang Ling
Published: April 2021

As the fourth largest staple crop in China, potatoes are a significant source of food and revenue, and provide diverse vitamins to human. However, the variation of vitamin retention in tubers after cooking were seldom evaluated. In this study, we evaluated the effects of steaming on water-soluble vitamins (vitamin B9 and vitamin C) and liposoluble vitamin (vitamin E) in tubers from eight potato cultivars grown in northern China. We found that these cultivars contained wide ranges of vitamin B9 (8.60–19.93 μg/100 g FW), vitamin C (46.67–155.44 mg/100 g FW), and vitamin E (15.34–33.82 mg/kg FW), with the highest vitamins B9, C, and E content in cultivars V7, XinDaPing, and QingShu 9, respectively. After steaming, vitamin contents decreased in most cultivars; levels of these three vitamins in tubers of cultivars ‘Tianshu11’ and ‘XinDaPing’ were higher than others, indicating that these two cultivars could be better sources among the detected ones for multiple vitamins after steaming.
Scale Effect and Correlation between Uniaxial Compressive Strength and Point Load Index for Limestone and Travertine
Authors: Contreras Solange , Saldaña Manuel , Toro Norman , Pérez-Rey Ignacio , González Manuel A. , González Javier
Published: April 2021

Determining the uniaxial compressive strength of intact rock is the primary objective of a geomechanical project, and a reliable estimate in the early phases saves time and costs for more sophisticated laboratory tests. The problem is knowing which of the correlations between the resistance to uniaxial compression and point load index are reliable, those that cover one or several types of rock (depending on the type of statistical adjustment). In this work, they were evaluated with respect to limestone and travertine from experimental results, and the statistical models of the scale effect of the point load index were determined, and the uniaxial compressive strength being estimated from correlations reported in literature. The limestone model was ascending (strength increases as diameter increases), while the travertine model was descending (strength decreases as diameter increases), obtaining similar exponents for the scale effect equations modeled from the uniaxial compressive strength and point load index in both cases.
Design, Optimization and Evaluation of a New Cylinder Attachment Geometry to Improve the Hopping Height of the Bionic One-Legged Robot
Authors: Zhao Donglai , Ge Wenjie , Mo Xiaojuan , Li Yuzhu , Wang Zhuo
Published: April 2021

Due to the high power-to-weight ratio and robustness, hydraulic cylinders are widely used in the actuation area of the legged robot systems. Most of these applications are focused on the motion stability, gait planning, and impedance control. However, the energy efficiency of the legged robotic system is also a very important point to be considered. Hopping locomotion requires a fast extension of the tibia leg at the end of the take-off phase, which causes a continuous increment of the cylinder velocity under the normally direct attachment geometry (DAG) of the cylinder. This leads to a high flow requirement, large pressure drop, and low energy efficiency. Therefore, we propose a four-bar mechanism attachment geometry (FMAG) to improve the energy efficiency by refining the relationship between the joint angle and cylinder displacement trend. The kinematic and dynamic models of the bionic one-legged robot are built to calculate the hopping process during the take-off phase. Based on the established dynamic models, the design parameters in both the DAG and FMAG are optimized to maximize the hopping height, respectively. The hopping experiments are conducted to verify the effectiveness of the new attachment geometry. The experimental results show that the robot hopping energy at the end of the take-off phase increases 14.8% under the FMAG.
Model-Based Dynamic Forecasting for Residential Construction Market Demand: A Systemic Approach
Authors: Kim Kyeong-Baek , Cho Ji-Hoon , Kim Sang-Bum
Published: April 2021

According to the previous research, proper demand forecasting could help construction-related firms in effective planning for future market changes. However, existing market demand forecasting models are somewhat limited, and most of them bear some critical shortcomings. This research aims to develop a forecasting model for the Korean residential construction industry using system dynamics. In developing the market forecasting model, this research uses variables that significantly impact future construction market change. Many of the existing models do not include as many variables as this model, and none of them have considered complex interlocking effects among these variables. This model is also the first model using a system-based approach by looking at the target industry as a ‘one complex system’ rather than focusing on individual variables’ impact on future market changes. By employing system dynamics, it is possible to consider qualitative and quantitative aspects and produce long-term market forecasting results. The developed market forecasting model consists of two main modules, the first being a prediction module for the grassroots construction market and the second for operation and maintenance (O&M) and the demolition market. Sixteen input variables are grouped into four categories: social, economy, regulation, and past market size among over 25 identified variables. The model utilizes a mathematical function system using the designed feedback loops in producing future market forecasts. Based on the validation tests with past market data, it turns out that the model is reliable, with the determination coefficient (R2) being over 0.7 on all tested occasions. According to the model’s forecasting results, the Korean construction market’s size is expected to be 231 billion won in 2015 and 286 billion won in 2030. However, the O&M market’s growth rate is expected to be higher than 180%, which is much bigger than those of the grass-root and demolition markets. Thus, this research model is realistic according to the construction paradigm change. This research is considered one of the pioneering studies in construction market forecasting by employing dynamic inter-relationships among various input variables. Therefore, the market forecasting results can be interpreted as more practical and can provide more insights to the construction industry stakeholders. The model is envisioned to provide the public sector with useful guidelines in preparing future public market supply strategies such as construction budget allocations. It would also be helpful for the private sector to develop more proactive and accurate demand strategies for timely decision-making.
Some of the Physical and Mechanical Properties of Particleboard Made from Betung Bamboo (Dendrocalamus asper)
Authors: Karlinasari Lina , Sejati Prabu Setia , Adzkia Ulfa , Arinana Arinana , Hiziroglu Salim
Published: April 2021

The objective of this study was to evaluate various physical and mechanical properties of experimental particleboard panels made from Asian giant bamboo (Dendrocalamus asper). Single layer panels having a density level of 0.75 g/cm3 from coarse and fine particles were used within the scope of this study. Thickness swelling, water absorption, surface roughness, and wettability characteristics of the samples were tested as physical properties while bending, internal bond strength, and screw withdrawal strength of the panels were considered for their mechanical properties. Resistance of the panels against termite and fungus were also determined. Based on the findings in the work both physical and mechanical properties of the panels made from coarse particles resulted in higher values than those made from fine particles with the exception of their internal bond strength. It appears that using fine particles in the panels enhanced their overall surface quality as well as wettability. Regarding biological deterioration of the samples, those made with coarse particles had better resistance. It seems that giant bamboo as a non-wood lignocellulosic species would have potential to be used as raw material to the manufacture value added particleboard with accepted characteristics.
Adaptive Semi-Structured Mesh Refinement Techniques for the Finite Element Method
Authors: Amor-Martin Adrian , Garcia-Castillo Luis E.
Published: April 2021

The adaptive mesh techniques applied to the Finite Element Method have continuously been an active research line. However, these techniques are usually applied to tetrahedra. Here, we use the triangular prismatic element as the discretization shape for a Finite Element Method code with adaptivity. The adaptive process consists of three steps: error estimation, marking, and refinement. We adapt techniques already applied for other shapes to the triangular prisms, showing the differences here in detail. We use five different marking strategies, comparing the results obtained with different parameters. We adapt these strategies to a conformation process necessary to avoid hanging nodes in the resulting mesh. We have also applied two special rules to ensure the quality of the refined mesh. We show the effect of these rules with the Method of Manufactured Solutions and numerical results to validate the implementation introduced.
Energy-Dispersive X-ray Spectroscopic Investigation of Failed Dental Implants Associated with Odontogenic Maxillary Sinusitis
Authors: Nguyen Truc Thi Hoang , Eo Mi Young , Sodnom-Ish Buyanbileg , Myoung Hoon , Kim Soung Min
Published: April 2021

The failed dental implant associated with maxillary sinusitis is a multifactorial phenomenon and should be investigated thoroughly. The inflammatory process induced by accumulated biofilm and wear debris may increase mucous secretion and mucous thickening, which finally may lead to severe complications such as maxillary sinusitis. The inflammatory cytokines might compromise the long-term osseointegration of the related implant. In this study, implants retrieved from three patients who experienced implant failure relating to maxillary sinusitis were investigated using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy. SEM analysis of the implant apical region revealed a less-compact bone structure, indicating the high bone turnover due to an inflammatory process. The ratio of calcium (Ca) and phosphorus (P) was negligible in all specimens. Detection of fluorine (F), sodium (Na), silicon (Si), gold (Au), aluminum (Al), and magnesium (Mg) confirmed the contamination. The selected cases presented different biological aspects that might play the central role in the failed dental implants associated with maxillary sinusitis: the contamination of potentially toxic elements, microorganism infection, and long perforation of implant apex into the sinus. Each of the above phenomena needs to be confirmed with further clinical study with a larger number of failed implants and accompanying tissue samples.
Design and Implementation of an Autonomous Electric Vehicle for Self-Driving Control under GNSS-Denied Environments
Authors: Barzegar Ali , Doukhi Oualid , Lee Deok-Jin
Published: April 2021

In this study, the hardware and software design and implementation of an autonomous electric vehicle are addressed. We aimed to develop an autonomous electric vehicle for path tracking. Control and navigation algorithms are developed and implemented. The vehicle is able to perform path-tracking maneuvers under environments in which the positioning signals from the Global Navigation Satellite System (GNSS) are not accessible. The proposed control approach uses a modified constrained input-output nonlinear model predictive controller (NMPC) for path-tracking control. The proposed localization algorithm used in this study guarantees almost accurate position estimation under GNSS-denied environments. We discuss the procedure for designing the vehicle hardware, electronic drivers, communication architecture, localization algorithm, and controller architecture. The system’s full state is estimated by fusing visual inertial odometry (VIO) measurements with wheel odometry data using an extended Kalman filter (EKF). Simulation and real-time experiments are performed. The obtained results demonstrate that our designed autonomous vehicle is capable of performing path-tracking maneuvers without using Global Navigation Satellite System positioning data. The designed vehicle can perform challenging path-tracking maneuvers with a speed of up to 1 m per second.
The Influence of Magnetic Turbulence on the Energetic Particle Transport Upstream of Shock Waves
Authors: Perri Silvia , Prete Giuseppe , Malara Francesco , Pucci Francesco , Zimbardo Gaetano
Published: April 2021

Energetic particles are ubiquitous in the interplanetary space and their transport properties are strongly influenced by the interaction with magnetic field fluctuations. Numerical experiments have shown that transport in both the parallel and perpendicular directions with respect to the background magnetic field is deeply affected by magnetic turbulence spectral properties. Recently, making use of a numerical model with three dimensional isotropic turbulence, the influence of turbulence intermittency and magnetic fluctuations on the energetic particle transport was investigated in the solar wind context. Stimulated by this previous theoretical work, here we analyze the parallel transport of supra-thermal particles upstream of interplanetary shock waves by using in situ particle flux measurements; the aim was to relate particle transport properties to the degree of intermittency of the magnetic field fluctuations and to their relative amplitude at the energetic particle resonant scale measured in the same regions. We selected five quasi-perpendicular and five quasi-parallel shock crossings by the ACE satellite. The analysis clearly shows a tendency to find parallel superdiffusive transport at quasi-perpendicular shocks, with a significantly higher level of the energetic particle fluxes than those observed in the quasi-parallel shocks. Furthermore, the occurrence of anomalous parallel transport is only weakly related to the presence of magnetic field intermittency.
Forecasting of Extreme Storm Tide Events Using NARX Neural Network-Based Models
Authors: Di Nunno Fabio , Granata Francesco , Gargano Rudy , de Marinis Giovanni
Published: April 2021

The extreme values of high tides are generally caused by a combination of astronomical and meteorological causes, as well as by the conformation of the sea basin. One place where the extreme values of the tide have a considerable practical interest is the city of Venice. The MOSE (MOdulo Sperimentale Elettromeccanico) system was created to protect Venice from flooding caused by the highest tides. Proper operation of the protection system requires an adequate forecast model of the highest tides, which is able to provide reliable forecasts even some days in advance. Nonlinear Autoregressive Exogenous (NARX) neural networks are particularly effective in predicting time series of hydrological quantities. In this work, the effectiveness of two distinct NARX-based models was demonstrated in predicting the extreme values of high tides in Venice. The first model requires as input values the astronomical tide, barometric pressure, wind speed, and direction, as well as previously observed sea level values. The second model instead takes, as input values, the astronomical tide and the previously observed sea level values, which implicitly take into account the weather conditions. Both models proved capable of predicting the extreme values of high tides with great accuracy, even greater than that of the models currently used.
Initial Results of Long-term Continuous Observation of Lightning Discharges by FALMA in Chinese Inland Plateau Region
Authors: Gao Panliang , Wu Ting , Wang Daohong
Published: April 2021

We started a long-term continuous observation of lightning discharges in the Chinese inland plateau region using a fast antenna lightning mapping array (FALMA). During the first year of observation, 2019, we recorded lightning discharges on 25 days in Yinchuan city, the capital of Ningxia. Most of the lightning discharges appeared to occur in the afternoons of individual thunderstorm days in August. We studied the cloud-to-ground (CG) flash percentages, lightning discharge source spatiotemporal distributions, and preliminary breakdown (PB) process characteristics for the two thunderstorm cases that produced the most frequent lightning flashes in 2019 over a wide area. It was found that (1) CG flashes in these two thunderstorms accounted for 28.4% and 32.5% of total lightning flashes, respectively; (2) most lightning discharge sources in these two thunderstorms occurred at temperatures between 5 and −30 °C, with a peak at around −10 °C; and (3) more than 90% of well-mapped PB processes of intracloud (IC) flashes propagated downward. By overlapping the altitudes and the progression directions of the PB processes on the lightning source spatiotemporal distributions, we inferred that the main negative charge of the two storms observed in Ningxia, China, was at a height of around −15 to −25 °C (7 to 9 km) and the main positive charge was at a height of around 5 to 0 °C (2 to 4 km).
A Quadratic Mean Field Games Model for the Langevin Equation
Authors: Camilli Fabio
Published: April 2021

We consider a Mean Field Games model where the dynamics of the agents is given by a controlled Langevin equation and the cost is quadratic. An appropriate change of variables transforms the Mean Field Games system into a system of two coupled kinetic Fokker–Planck equations. We prove an existence result for the latter system, obtaining consequently existence of a solution for the Mean Field Games system.
On Convex F-Contraction in b-Metric Spaces
Authors: Huang Huaping , Mitrović Zoran D. , Zoto Kastriot , Radenović Stojan
Published: April 2021

In this paper, we introduce a notion of convex F-contraction and establish some fixed point results for such contractions in b-metric spaces. Moreover, we give a supportive example to show that our convex F-contraction is quite different from the F-contraction used in the existing literature since our convex F-contraction does not necessarily contain the continuous mapping but the F-contraction contains such mapping. In addition, via some facts, we claim that our results indeed generalize and improve some previous results in the literature.
The Long-Term Effects of High-Fat and High-Protein Diets on the Metabolic and Endocrine Activity of Adipocytes in Rats
Authors: Pruszyńska-Oszmałek Ewa , Wojciechowska Małgorzata , Sassek Maciej , Krauss Hanna , Leciejewska Natalia , Szczepankiewicz Dawid , Ślósarz Piotr , Nogowski Leszek , Kołodziejski Paweł A.
Published: April 2021

The increasing prevalence of overweight and obesity and the rising awareness of their negative consequences are forcing researchers to take a new view of nutrition and its consequences for the metabolism of whole organisms as well as the metabolism of their individual systems and cells. Despite studies on nutrition having been carried out for a few decades, not many of them have focused on the impacts of these diets on changes in the metabolism and endocrine functions of isolated adipocytes. Therefore, we decided to investigate the effects of the long-term use (60 and 120 days) of a high-fat diet (HFD) and of a high-protein diet (HPD) on basic metabolic processes in fat cells—lipogenesis, lipolysis, and glucose uptake—and endocrine function, which was determined according to the secretion of adipokines into the incubation medium. Our results proved that the HPD diet improved insulin sensitivity, increased the intracellular uptake of glucose (p < 0.01) and its incorporation into lipids (p < 0.01) and modulated the endocrine function of these cells (decreasing leptin secretion; p < 0.01). The levels of biochemical parameters in the serum blood also changed in the HPD-fed rats. The effects of the HFD were inverse, as expected. We observed a decrease in adiponectin secretion and a diminished rate of lipogenesis (p < 0.01). Simultaneously, the secretion of leptin and resistin (p < 0.01) from isolated adipocytes increased. In conclusion, we noted that the long-term use of HPD and HFD diets modulates the metabolism and endocrine functions of isolated rat adipocytes. We summarize that an HFD had a negative effect on fat tissue functioning, whereas an HPD had positive results, such as increased insulin sensitivity and an improved metabolism of glucose and lipids in fat tissue. Moreover, we noticed that negative metabolic changes are reflected more rapidly in isolated cells than in the metabolism of the whole organism.
Blastocystis sp. Carriage and Irritable Bowel Syndrome: Is the Association Already Established?
Authors: Salvador Fernando , Lobo Beatriz , Goterris Lidia , Alonso-Cotoner Carmen , Santos Javier , Sulleiro Elena , Bailo Begoña , Carmena David , Sánchez-Montalvá Adrián , Bosch-Nicolau Pau , Espinosa-Pereiro Juan , Fuentes Isabel , Molina Israel
Published: April 2021

Background: The aim of the present study is to describe the occurrence of Blastocystis sp. detection among asymptomatic subjects and patients with irritable bowel syndrome in order to evaluate the potential association between irritable bowel syndrome and the parasitic infection. Methods: Cross-sectional study where adult patients with irritable bowel syndrome diagnosed according to Rome IV criteria were included. A control group was formed by asymptomatic subjects older than 18 years. Exclusion criteria were: immunosuppressive condition or having received any drug with demonstrated activity against Blastocystis sp. within the last 6 months before study inclusion. Epidemiological and clinical information was collected from all included participants. Two stool samples were obtained from all participants: one sample for microscopic examination and one sample for Blastocystis sp. PCR detection. Blastocystis sp. infection was defined by the positivity of any of the diagnostic techniques. Results: Seventy-two participants were included (36 asymptomatic subjects and 36 patients with irritable bowel syndrome). Thirty-five (48.6%) were men, and median age of participants was 34 (IQR 29–49) years. The overall rate of Blastocystis sp. carriage was 27.8% (20/72). The prevalence assessed through microscopic examination was 22.2% (16/72), while the prevalence measured by PCR was 15.3% (11/72). When comparing the presence of Blastocystis sp. between asymptomatic subjects and IBS patients, we did not find any statistically significant difference (36.1% vs. 19.4% respectively, p = 0.114). Conclusions: regarding the occurrence of Blastocystis sp., no differences were found between asymptomatic participants and patients with irritable bowel disease irrespective of the diagnostic technique performed.
Genetic Diversity in Diospyros Germplasm in the Western Caucasus Based on SSR and ISSR Polymorphism
Authors: Samarina Lidia S. , Malyarovskaya Valentina I. , Reim Stefanie , Koninskaya Natalia G. , Matskiv Alexandra O. , Tsaturyan Gregory A. , Rakhmangulov Ruslan S. , Shkhalakhova Ruset M. , Shurkina Ekaterina S. , Kulyan Raisa V. , Omarova Zuhra M. , Omarov Magomed D. , Ryndin Alexey V.
Published: April 2021

Persimmon germplasm in the Western Caucasus represent one of the most northerly collections. In our study, 51 commercial cultivars of D. kaki, 3 accessions of D. virginiana and 57 D. lotus accessions from six geographically distant populations were investigated using 19 microsatellite and 10 inter simple sequence repeat (ISSR) markers. After STRUCTURE analysis, the single accessions of Diospyros were allocated to three genetic clusters. Genetic admixtures in the important genotypes of D. kaki were revealed, whereas D. lotus accessions showed no admixture with other genetic clusters. The correspondence of genetic data and phenotypical traits was estimated in the D. kaki collection. The most frost tolerant genotypes of the collection, such as “Mountain Rogers”, “Nikitskaya Bordovaya”, “Rossiyanka”, “MVG Omarova”, “Meader”, “Costata”, “BBG”, and “Jiro”, showed a high percentage of genetic admixtures and were grouped close to D. virginiana. Some of these genotypes are known to be interspecific hybrids with D. virginiana. A low level of genetic diversity between the distant D. lotus populations was revealed and it can be speculated that D. lotus was introduced to the Western Caucasus from a single germplasm source. These results are an important basis for the implementation of conservation measures, developing breeding strategies, and improving breeding efficiency.
The Initial Course of IL1β, IL-6, IL-8, IL-10, IL-12, IFN-γ and TNF-α with Regard to Severity Grade in Acute Pancreatitis
Authors: Sternby Hanna , Hartman Hannes , Thorlacius Henrik , Regnér Sara
Published: April 2021

Clinical reports on early immune dysregulation in acute pancreatitis (AP) are scarce. Herein we investigate the initial temporal development of selected biomarkers. Blood samples were taken at 0–24 and 25–48 h after onsets of AP were acquired. Mean values and temporal intermediate difference (delta-values) of IL-1β, IL-6, IL-8, IL-10, IL-12, IFN-γ and TNF-α were calculated. Differences between severity groups, predictive capacity of the biomarkers and association with severe disease were analyzed. Paired comparison of samples (n = 115) taken at 0–24 and 25–48 h after onsets of AP showed a change over time for IL-1β, IL-6, IL-8 and IL-10 (p < 0.05) and a significant difference between severity groups after 24 h. In ROC-analysis an IL-6 cut-off level of 196.6 pg/mL could differentiate severe AP (sensitivity 81.9, specificity 91.3). The delta-values of IL-1β and IL-6 were significantly associated with severe outcomes (odds ratios 1.085 and 1.002, respectively). Data of this work demonstrate a distinct change in IL-1β, IL-8, IL-10 and IL-6 over the first 48 h after onset of AP. The temporal development of biomarkers can assist in the early stratification of the disease. Herein IL-1β and IL-6 were associated with severe disease, however the prognostic capacity of investigated biomarkers is low.
Effect of Surface Roughness on Aggregation of Polypeptide Chains: A Monte Carlo Study
Authors: Co Nguyen , Li Mai
Published: April 2021

The self-assembly of amyloidogenic peptides and proteins into fibrillar structures has been intensively studied for several decades, because it seems to be associated with a number of neurodegenerative diseases, such as Alzheimer’s and Parkinson’s disease. Therefore, understanding the molecular mechanisms of this phenomenon is important for identifying an effective therapy for the corresponding diseases. Protein aggregation in living organisms very often takes place on surfaces like membranes and the impact of a surface on this process depends not only on the surface chemistry but also on its topology. Our goal was to develop a simple lattice model for studying the role of surface roughness in the aggregation kinetics of polypeptide chains and the morphology of aggregates. We showed that, consistent with the experiment, an increase in roughness slows down the fibril formation, and this process becomes inhibited at a very highly level of roughness. We predicted a subtle catalytic effect that a slightly rough surface promotes the self-assembly of polypeptide chains but does not delay it. This effect occurs when the interaction between the surface and polypeptide chains is moderate and can be explained by taking into account the competition between energy and entropy factors.
Comparison of the Benzanthrone Luminophores: They Are Not Equal for Rapid Examination of Parafasciolopsis fasciolaemorpha (Trematoda: Digenea)
Authors: Rubenina Ilze , Gavarane Inese , Kirilova Elena , Mezaraupe Ligita , Kirjusina Muza
Published: April 2021

Luminescent derivatives of benzanthrone are becoming more useful based on their light-absorbing and fluorescent-emitting properties. Our previous studies showed that luminescent staining properties of the same benzanthrone dye differ for variable parasite samples. Therefore, two types of benzanthrone dyes were prepared. One has a strongly basic amidine group and a halogen atom, and the other has an amide moiety and a tertiary amine group. Trematoda Parafasciolopsis fasciolaemorpha is a liver fluke of a moose (Alces alces) and has a significant influence on the health and abundance of the moose population. Staining protocols for parasite P. fasciolaemorpha specific organ or organ systems imaging are mostly time-consuming and labor-intensive. The study aimed to compare the fixation technique and the staining protocol by synthesized benzanthrone luminescent dyes to determine detailed morphology, anatomical arrangement of the organ systems and gross organization of the muscle layers of P. fasciolaemorpha using confocal laser scanning microscopy. Luminophores were tested for samples fixed in different fixatives. Developed dyes and staining protocol resulting in imaging of all parts of trematode without additional sample preparation procedures, which usually are required for parasite examination. Obtained results confirmed that the most qualitative results could be reached using 3-N-(2-piperidinylacetamido)benzanthrone dye which has amide moiety and a tertiary amine group. Based on obtained results, 3-N-(2-piperidinylacetamido)benzanthrone gave more qualitative parasite visualization than 2-bromo-3-N-(N′,N′-dimethylformamidino)benzanthrone.
EPHA3 Contributes to Epigenetic Suppression of PTEN in Radioresistant Head and Neck Cancer
Authors: Kim Song-Hee , Kang Byung-Chul , Seong Daseul , Lee Won-Hyeok , An Jae-Hee , Je Hyoung-Uk , Cha Hee-Jeong , Chang Hyo-Won , Kim Sang-Yoon , Kim Seong-Who , Han Myung-Woul
Published: April 2021

EPHA3, a member of the EPH family, is overexpressed in various cancers. We demonstrated previously that EPHA3 is associated with radiation resistance in head and neck cancer via the PTEN/Akt/EMT pathway; the inhibition of EPHA3 significantly enhances the efficacy of radiotherapy in vitro and in vivo. In this study, we investigated the mechanisms of PTEN regulation through EPHA3-related signaling. Increased DNA methyltransferase 1 (DNMT1) and enhancer of zeste homolog 2 (EZH2) levels, along with increased histone H3 lysine 27 trimethylation (H3K27me3) levels, correlated with decreased levels of PTEN in radioresistant head and neck cancer cells. Furthermore, PTEN is regulated in two ways: DNMT1-mediated DNA methylation, and EZH2-mediated histone methylation through EPHA3/C-myc signaling. Our results suggest that EPHA3 could display a novel regulatory mechanism for the epigenetic regulation of PTEN in radioresistant head and neck cancer cells.
Antibacterial Activity and Reversal of Multidrug Resistance of Tumor Cells by Essential Oils from Fresh Leaves, Flowers, and Stems of Montanoa quadrangularis Schultz Bipontinus (Asteraceae) Collected in Mérida—Venezuela
Authors: Rojas Janne , Ndong Ntoutoume Gautier Mark-Arthur , Martin Patrick , Morillo Marielba
Published: April 2021

Essential oils obtained by hydrodistillation of Montanoa quadrangularis leaves, flowers, and stems were analyzed by GC and GC/MS techniques revealing myrcene, limonene, β-phellandrene, and sabinene among the main components. The aim of the present study was to evaluate the MDR modulator activity on human MDR1 gene transfected mouse lymphoma cell line and the antimicrobial activity on the essential oils obtained from different parts of the species under investigation. The results revealed that MQL caused a similar increase in the fluorescence activity of the cells at 0.02 μL/mL comparing to the Verapamil® value. The antimicrobial assay was carried out according to the disc diffusion method. Five different bacterial strains (Staphylococcus epidermidis, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli AG 100, and Escherichia coli AG100A) were treated with the essential oils and the zones of inhibition were determined on TSA plates and TSA agar plates supplemented with Tween 20. MQF and MQL showed activity against B. subtilis, S. epidermidis, and E. coli AG 100A while MQS was only active against E. coli AG 100A on TSA agar plates experiment. In case of TSA agar plates supplemented with 0.1 v/v% Tween 20 detergent, MQF showed inhibition on B. subtilis, S. epidermidis, and E. coli AG 100A; MQL was active against B. subtilis, E. coli AG 100, and E. coli AG 100A while MQS was only active against E. coli AG 100A.
Patisiran in hATTR Amyloidosis: Six-Month Latency Period before Efficacy
Authors: Gentile Luca , Russo Massimo , Luigetti Marco , Bisogni Giulia , Di Paolantonio Andrea , Romano Angela , Guglielmino Valeria , Arimatea Ilenia , Sabatelli Mario , Toscano Antonio , Vita Giuseppe , Mazzeo Anna
Published: April 2021

Hereditary amyloidosis associated with mutations in the transthyretin gene (hATTR) is a progressive devastating disease, with a fatal outcome occurring within 10years after onset. In recent years, TTR gene silencing therapy appeared as a promising therapeutic strategy, showing evidence that disease progression can be slowed and perhaps reversed. We report here 18 subjects affected by hATTR amyloidosis treated with patisiran, a small interfering RNA acting as TTR silencer, and evaluated with a PND score, the NIS and NIS-LL scale, and a Norfolk QOL-DN questionnaire at baseline and then every 6 months. A global clinical stabilizationwas observed for the majority of the patients, with mild-moderate improvements in some cases, even in advanced disease stage (PND score > 2). Analysis of NIS, NIS-LL and Norfolk QOL-DN results, and PND score variation suggest the possible presence of a 6-month latency period prior to benefit of treatment.