bluuebunny/crossref_metadata_2025 huggingface dataset:
Interference Challenges and Management in B5G Network Design: A Comprehensive Review
Authors: Alzubaidi Osamah Thamer Hassan , Hindia MHD Nour , Dimyati Kaharudin , Noordin Kamarul Ariffin , Wahab Amelia Natasya Abdul , Qamar Faizan , Hassan Rosilah
Published: September 2022

Beyond Fifth Generation (B5G) networks are expected to be the most efficient cellular wireless networks with greater capacity, lower latency, and higher speed than the current networks. Key enabling technologies, such as millimeter-wave (mm-wave), beamforming, Massive Multiple-Input Multiple-Output (M-MIMO), Device-to-Device (D2D), Relay Node (RN), and Heterogeneous Networks (HetNets) are essential to enable the new network to keep growing. In the forthcoming wireless networks with massive random deployment, frequency re-use strategies and multiple low power nodes, severe interference issues will impact the system. Consequently, interference management represents the main challenge for future wireless networks, commonly referred to as B5G. This paper provides an overview of the interference issues relating to the B5G networks from the perspective of HetNets, D2D, Ultra-Dense Networks (UDNs), and Unmanned Aerial Vehicles (UAVs). Furthermore, the existing interference mitigation techniques are discussed by reviewing the latest relevant studies with a focus on their methods, advantages, limitations, and future directions. Moreover, the open issues and future directions to reduce the effects of interference are also presented. The findings of this work can act as a guide to better understand the current and developing methodologies to mitigate the interference issues in B5G networks.
Relay Protection and Automation Algorithms of Electrical Networks Based on Simulation and Machine Learning Methods
Authors: Kulikov Aleksandr , Loskutov Anton , Bezdushniy Dmitriy
Published: September 2022

The tendencies and perspective directions of development of modern digital devices of relay protection and automation (RPA) are considered. One of the promising ways to develop protection and control systems is the development of fundamentally new algorithms for recognizing emergency modes. They work in accordance with the triggering rule, which is formed after processing the results of model experiments. These algorithms are able to simultaneously control a large number of features or mode parameters (current, voltage, resistance, phase, etc.). Thus, the algorithms are multidimensional. This approach in RPA becomes available since the computing power of modern processors is quite enough to process the required amount of statistical data on the parameters of possible normal and emergency operation modes of electrical network sections. The application of classical machine learning algorithms in RPA tasks is analyzed, in particular, methods of k-nearest neighbors, logistic regression, and support vectors. The use of specialized trainable triggering elements is studied both for building new protections and for improving the sophistication of traditional types of relay protection devices. The developed triggering elements of the multi-parameter RPA contribute to an increase in the sensitivity and recognition of accidents. The proposed methods for recognizing emergency modes are appropriate for implementation in intelligent electronic devices (IEDs) of digital substations.
Progress and Outlook in Wind Energy Research
Authors: Bangga Galih
Published: September 2022

Wind energy research plays a vital role in the possibility of the success story of wind energy as one of the most promising sustainable energy sources. This continuous process has been achieved from the era of small wind turbines to the current Multi-WM standard and beyond. In this editorial paper, the progress and future outlook of wind energy research in two main aspects are discussed. The first aspect is in the area of wind turbine design and computations which covers engineering modeling and high-fidelity approaches. The second part of the paper discusses the usage of data-driven approaches in wind energy research. The paper compiles and presents the key findings of several recent studies in these two areas of research. The discussion of the paper is focused on the technical aspects of wind energy modeling. The main aim is to provide an overview about the direction of current research and its importance to meet future expectations.
On the Development of Overcurrent Relay Optimization Problem for Active Distribution Networks
Authors: Prenc Rene , Rojnić Michele , Franković Dubravko , Vlahinić Saša
Published: September 2022

The goal of this review paper will be to address complex optimization functions in the area of overcurrent relay optimization, to inspect and valorize their objectives and to critically examine their application in real distribution networks. Special emphasis will be put on observing the optimization of discrimination time between primary and backup relay pairs, and methods which prevent the latter becoming penalty functions will be shown. Furthermore, the impact of distributed generation units on the overcurrent relay optimization problem will be elaborated in detail. Protection settings of all the existing and new relays must be thoroughly inspected before the connection of new production units, because contributing fault currents may have a significant effect on the solution of the overcurrent optimization problem. This is because the relays being used are of an inverse-type. Next, meshed network operation will be critically assessed in comparison with the actual practice of radial operation, and some topologies will be highlighted for future research, while others will be discarded. The distribution network in mesh operation implicitly suggests using numerical relays on both sides of protected elements (usually lines), so their total number will be much higher than in radial operation. Finally, a relatively new concept of adaptive distribution network protection will be reviewed, and its potential application to the overcurrent relay optimization problem will be examined. The purpose of this review paper will be to lay a groundwork for future research papers by inspecting the overall development of the overcurrent relay optimization problem for contemporary and future active distribution networks.
Review of Turbine Parameterization Models for Large-Eddy Simulation of Wind Turbine Wakes
Authors: Li Zhaobin , Liu Xiaohao , Yang Xiaolei
Published: September 2022

Wind turbine parameterization models, which are often employed to avoid the computational cost of resolving the blade aerodynamics, are critical for the capability of large-eddy simulation in predicting wind turbine wakes. In this paper, we review the existing wind turbine parameterization models, i.e., the actuator disk model, the actuator line model, and the actuator surface model, by presenting the fundamental concepts, some advanced issues (i.e., the force distribution approaches, the method for velocity sampling, and the tip loss correction), and their applications to utility-scale wind farms. Emphasis is placed on the predictive capability of different parameterizations for different wake characteristics, such as the blade load, the tip vortices and hub vortex in the near wake, and the meandering of the far wake. The literature demonstrated the importance of taking into account the effects of nacelle and tower in wind turbine wake predictions. The predictive capability of the actuator disk model with different model complexities, which is preferred in wind farm simulations, is systematically reviewed for different inflows and different wind turbine designs. Applications to wind farms show good agreements between simulation results and measurements.
Recent Advances in Sustainable Energy and Environmental Development
Authors: Calise Francesco , Figaj Rafał
Published: September 2022

The energy sector, along with the conditions of the natural and built environment, are significantly affected by the tremendous increase in total energy consumption [...]
A Comprehensive Review on Pretreatment Methods for Enhanced Biogas Production from Sewage Sludge
Authors: Mitraka Georgia-Christina , Kontogiannopoulos Konstantinos N. , Batsioula Maria , Banias George F. , Zouboulis Anastasios I. , Kougias Panagiotis G.
Published: September 2022

The treatment of municipal wastewater is considered a cornerstone for the protection of public health and environment. However, a major issue derived from this process is the large quantities of produced sewage sludge. Although anaerobic digestion is a widely applied method in Wastewater Treatment Plants (WWTPs) aiming to stabilize the sludge and to recover energy in the form of methane, it is usually limited due to the reduced decomposition efficiency and slow biodegradation rate of this recalcitrant substrate. For this reason, various pretreatment methods have been proposed aiming to modify the sludge structure, solubilize the organic matter, and decrease the crystallinity of sludge so as to accelerate hydrolysis and consequently enhance methane production. The current research is a comprehensive collection of recent advances in pretreatment technologies that can be potentially applied in wastewater treatment facilities. The critical review analysis presented herein reveals the several advantages and drawbacks, as well as the technical opportunities of the pretreatment methods and provides an assessment of their feasibility/applicability from an energetic, environmental, and economic point of view.
Adsorption Solar Air Conditioning System for Singapore Climate
Authors: Tamainot-Telto Zacharie , Metcalf Stephen John , Yande Neilson Ng
Published: September 2022

The design of an adsorption solar air conditioning system is investigated by using a model with an activated carbon–methanol working pair. This system is analysed with the solar insolation levels and ambient temperatures of Singapore. The proposed design mainly consists of two tubular reactor heat exchangers (TRHEXs) operating out of phase and driven by heat from an evacuated tube solar collector (ETSC). The pair of TRHEXs act as a thermal compressor and contain about 2.275 kg of activated carbon per reactor. The evacuated tube solar collector (ETSC) has better performance and is more cost effective than the flat plate solar collector (FPSC), even though it has a higher cost per unit. On the hottest day of the year, the proposed adsorption system has a maximum cooling power of 2.6 kW and a COP of 0.43 at a maximum driving temperature of 139 °C with a 9.8 m2 ETSC area. The system has a total estimated cost of EUR 10,550 corresponding to about SGD 14,800 with a 7-year payback time. At similar cooling capacities, the adsorption air conditioning system is expected to be more cost effective than the conventional system beyond an expected period of 7 years, with an expected lifetime of 15 to 20 years.
Numerical and Experimental Study of a PVT Water System under Daily Weather Conditions
Authors: Korkut Talha , Gören Aytaç , Rachid Ahmed
Published: September 2022

Worldwide need for renewable energy sources increases significantly with the drastic negative greenhouse effects of climate change. This study considers a water-cooled hybrid thermo-electric panel (PV/T) which contributes to better harvesting of solar energy. A numerical CFD model was developed for power generation of a standard PV panel as well as for a water-based PV/T system laminated with polymer matrix composite (PMC) materials, and user-defined functions (UDFs) were developed and integrated with the CFD model to implement exact boundary conditions. Experimentation under daily weather conditions was carried out in order to validate the numerical CFD model by measuring the surface temperatures of PV and PV/T systems as well as the temperatures of the water inlet and outlet of the cooling system. The results show that the maximum and minimum deviations of the surface temperature between numerical and experimental studies matched well compared with the studies performed in the literature. Moreover, the numerical model had a rapid response to temperature changes of PV and PV/T modules under sudden weather changes (cloudy/sunny). It was shown that the electrical efficiency of the cooled PV/T module can achieve 20.8% in addition to a thermal efficiency of 53.5%. The current study is a validation of the performance of polymer composite laminated water-cooled PV/T systems under daily weather conditions.
Hydraulic Performance of a Francis Turbine with a Variable Draft Tube Guide Vane System to Mitigate Pressure Pulsations
Authors: Joy Jesline , Raisee Mehrdad , Cervantes Michel J.
Published: September 2022

The present paper demonstrates a proof-of-concept by introducing a variable guide vane system in the draft tube of a high-head Francis model turbine. The aim is to examine the hydraulic performance of the turbine while mitigating the pressure pulsations in the draft tube. The guide vanes can rotate about an axis up to ±45°. The pressure pulsations mitigation studies were performed at lower- and upper-part loads. The hydraulic performance was examined at all operating ranges within the turbine head. There were six guide vane configurations considered between ±45°. The findings demonstrate that the highest efficiency loss with a guide vane configuration that mitigates the pressure pulsations is marginal, with modest improvements at the best efficiency point. The pressure pulsations are 100% mitigated at the lower part load, and there is a maximum decrement in the pressure pulsations up to 80% at the upper part load. The study demonstrates that such a system can improve the operational flexibility of the hydro-turbine by mitigating the pressure pulsations and marginally affecting its hydraulic performance.
CFD Study of High-Speed Train in Crosswinds for Large Yaw Angles with RANS-Based Turbulence Models including GEKO Tuning Approach
Authors: Szudarek Maciej , Piechna Adam , Prusiński Piotr , Rudniak Leszek
Published: September 2022

Crosswind action on a train poses a risk of vehicle overturning or derailment. To assess if new train designs fulfill the safety requirements, computational fluid dynamics is commonly used. This article presents a comprehensive wind flow analysis on an example of a TGV high-speed train. Large yaw angle range is studied with the application of widely used Reynolds-averaged Navier–Stokes (RANS) turbulence models. The predictive performance of popular RANS-based models in that regime has not been reported extensively before. The context of simulations is a study of crosswind stability using methodology presented in norm EN 14067-6:2018. It is shown that for yaw angles up to 45 degrees, aerodynamic forces predicted by all the studied RANS-based models are consistent with experimental data. At larger yaw angles, flow structure becomes complicated, separation lines are no longer defined by geometry, and significant discrepancies between turbulence models appear, with relative differences between models up to 30%. A detailed study was performed to investigate differences between turbulence models for specific angles of 40, 60, and 80 degrees, which correspond to distinctive ranges of moment characteristics. Finally, a successful attempt was made to tune a GEKO turbulence model to fit the experimental data. This allowed us to reduce the maximum relative error in comparison to the experiment in the full yaw angles range down to 12.7%, which is in line with the norm requirements.
Unsteady-State CO2 Foam Generation and Propagation: Laboratory and Field Insights
Authors: Alcorn Zachary Paul , Sæle Aleksandra , Karakas Metin , Graue Arne
Published: September 2022

This work presents a multiscale experimental and numerical investigation of CO2 foam generation, strength, and propagation during alternating injection of surfactant solution and CO2 at reservoir conditions. Evaluations were conducted at the core-scale and with a field-scale radial simulation model representing a CO2 foam field pilot injection well. The objective of the experimental work was to evaluate foam generation, strength, and propagation during unsteady-state surfactant-alternating-gas (SAG) injection. The SAG injection rapidly generated foam based upon the increased apparent viscosity compared to an identical water-alternating-gas (WAG) injection, without surfactant. The apparent foam viscosity of the SAG continually increased with each subsequent cycle, indicating continued foam generation and propagation into the core. The maximum apparent viscosity of the SAG was 146 cP, whereas the maximum apparent viscosity of the WAG was 2.4 cP. The laboratory methodology captured transient CO2 foam flow which sheds light on field-scale CO2 foam flow. The single-injection well radial reservoir simulation model investigated foam generation, strength, and propagation during a recently completed field pilot. The objective was to tune the model to match the observed bottom hole pressure data from the foam pilot and evaluate foam propagation distance. A reasonable match was achieved by reducing the reference mobility reduction factor parameter of the foam model. This suggested that the foam generated during the pilot was not as strong as observed in the laboratory, but it has propagated approximately 400 ft from the injection well, more than halfway to the nearest producer, at the end of pilot injection.
A Fast Signal-Processing Method for Electromagnetic Ultrasonic Thickness Measurement of Pipelines Based on UKF and SMO
Authors: Zhu Huichao , Tu Jun , Cai Chen , Deng Zhiyang , Wu Qiao , Song Xiaochun
Published: September 2022

Electromagnetic ultrasonic testing technology has advantages in measuring the thickness of pipelines in service. However, the ultrasonic signal is susceptible to corrosions on the internal and external surfaces of the pipeline. Since the electromagnetic ultrasonic signal is nonlinear, and a dynamic model is difficult to establish accurately, in this paper, a new unscented Kalman filter (UKF) method based on a sliding mode observer (SMO) is proposed. The experiments, conducted on five different testing samples, validate that the proposed method can effectively process the signals drowned in noise and accurately measure the wall thickness. Compared with FFT and UKF, the signal-to-noise ratio of the signals processed by SMO–UKF shows a maximum increase of 155% and 171%. Meanwhile, a random assignment method is proposed for the self-regulation of hyper parameters in the process of Kalman filtering. Experimental results show that the automatic adjustment of hyper parameters can be accomplished in finite cycle numbers and greatly shortens the overall filtering time.
A Novel Model-Free Predictive Control for T-Type Three-Level Grid-Tied Inverters
Authors: Yin Zheng , Hu Cungang , Luo Kui , Rui Tao , Feng Zhuangzhuang , Lu Geye , Zhang Pinjia
Published: September 2022

The model-free predictive control (MFPC) scheme is an effective scheme to enhance the parameter robustness of model predictive control. However, the MFPC scheme can be affected by the current gradient updating frequency. This paper proposes an improved MFPC scheme for a T-type three-level inverter. First, a novel current gradient updating method is designed to estimate all current gradients per control period, which uses the current gradient relationship between different voltage vectors and eliminates the effect of current gradients updating stagnation. Moreover, a sector judgment method based on the current gradient is proposed. Redundant small vectors are accurately judged and the computational burden is greatly reduced. Finally, simulation and experimental comparisons on a T-type three-level inverter verify the effectiveness of the proposed MFPC scheme.
Evaluation of Solar Energy Powered Seawater Desalination Processes: A Review
Authors: Al-Obaidi Mudhar A. , Zubo Rana H. A. , Rashid Farhan Lafta , Dakkama Hassan J. , Abd-Alhameed Raed , Mujtaba Iqbal M.
Published: September 2022

Solar energy, amongst all renewable energies, has attracted inexhaustible attention all over the world as a supplier of sustainable energy. The energy requirement of major seawater desalination processes such as multistage flash (MSF), multi-effect distillation (MED) and reverse osmosis (RO) are fulfilled by burning fossil fuels, which impact the environment significantly due to the emission of greenhouse gases. The integration of solar energy systems into seawater desalination processes is an attractive and alternative solution to fossil fuels. This study aims to (i) assess the progress of solar energy systems including concentrated solar power (CSP) and photovoltaic (PV) to power both thermal and membrane seawater desalination processes including MSF, MED, and RO and (ii) evaluate the economic considerations and associated challenges with recommendations for further improvements. Thus, several studies on a different combination of seawater desalination processes of solar energy systems are reviewed and analysed concerning specific energy consumption and freshwater production cost. It is observed that although solar energy systems have the potential of reducing carbon footprint significantly, the cost of water production still favours the use of fossil fuels. Further research and development on solar energy systems are required to make their use in desalination economically viable. Alternatively, the carbon tax on the use of fossil fuels may persuade desalination industries to adopt renewable energy such as solar.
Modeling of Photovoltaic Array Based on Multi-Agent Deep Reinforcement Learning Using Residuals of I–V Characteristics
Authors: Zhang Jingwei , Yang Zenan , Ding Kun , Feng Li , Hamelmann Frank , Chen Xihui , Liu Yongjie , Chen Ling
Published: September 2022

Currently, the accuracy of modeling a photovoltaic (PV) array for fault diagnosis is still unsatisfactory due to the fact that the modeling accuracy is limited by the accuracy of extracted model parameters. In this paper, the modeling of a PV array based on multi-agent deep reinforcement learning (RL) using the residuals of I–V characteristics is proposed. The environment state based on the high dimensional residuals of I–V characteristics and the corresponding cooperative reward is presented for the RL agents. The actions of each agent considering the damping amplitude are designed. Then, the entire framework of modeling a PV array based on multi-agent deep RL is presented. The feasibility and accuracy of the proposed method are verified by the one-year measured data of a PV array. The experimental results show that the higher modeling accuracy of the next time step is obtained by the extracted model parameters using the proposed method, compared with that using the conventional meta-heuristic algorithms and the analytical method. The daily root mean square error (RMSE) is approximately 0.5015 A on the first day, and converges to 0.1448 A on the last day of training. The proposed multi-agent deep RL framework simplifies the design of states and rewards for extracting model parameters.
Analysis of 18 Free Amino Acids in Honeybee and Bumblebee Honey from Eastern and Northern Europe and Central Asia Using HPLC-ESI-TQ-MS/MS Approach Bypassing Derivatization Step
Authors: Dimins Fredijs , Cinkmanis Ingmars , Radenkovs Vitalijs , Augspole Ingrida , Valdovska Anda
Published: September 2022

The profile of amino acids and mono- and disaccharides in conventional polyfloral honey originated from Latvia and Tajikistan and less found in nature bumblebee honey from Russia was investigated. The analysis of free amino acids (FAAs) accomplished by multiple reaction monitoring (MRM) using triple quadrupole mass selective detection (HPLC-ESI-TQ-MS/MS) revealed the presence of 17 FAAs. The concentration of FAAs varied in the range of 0.02–44.41 mg 100 g−1 FW. Proline was the main representative of FAAs, contributing to the total amount of FAAs from 41.7% to 80.52%. The highest concentration of proline was found in bumblebee and buckwheat honey, corresponding to 44.41 and 41.02 mg 100 g−1, respectively. The concentration of essential amino acids (AAs), i.e., leucine, and isoleucine was found to be the highest in buckwheat honey contributing up to 12.5% to the total amount of FAAs. While, the concentration of branched-chain AAs fluctuated within the range of 1.08–31.13 mg 100 g−1 FW, with buckwheat honey having the highest content and polyfloral honey the lowest, respectively. The results of this study confirmed the abundance of FAAs both in honeybee and bumblebee honey. However, the concentration of individual FAAs, such as proline, aspartic acid, leucine, and isoleucine in bumblebee honey was many folds higher than observed in honeybee polyfloral honey.
The Synthesis, Characterization, and Protein-Release Properties of Hydrogels Composed of Chitosan-Zingiber offcinale Polysaccharide
Authors: Jing Yongshuai , Zhang Yameng , Cheng Wenjing , Li Mingsong , Hu Beibei , Zheng Yuguang , Zhang Danshen , Wu Lanfang
Published: September 2022

Most proteins given orally have low bioavailability and are easily eliminated by rapid metabolism in vivo. In order to immobilize the drug at the site of administration and delay its release, a natural, gentle release system was designed. In this study, a heteropolysaccharide (ZOP) was isolated from Zingiber officinale using an ultrasonic assisted extraction method. ZOP Ara = 1.97: 1.15: 94.33: 1.48: 1.07. The ZOP/Chitosan (CS) composite hydrogel was synthesized using epichlorohydrin (ECH) as a cross-linking agent. The structure, morphology, and water-holding capacity of the composite hydrogel were characterized. The data showed that the addition of ZOP improved the hardness and water-holding capacity of the material. A swelling ratio test showed that the prepared hydrogel was sensitive to pH and ionic strength. In addition, the degradation rate of the hydrogel in a phosphate-buffered saline (PBS) solution with a pH value of 1.2 was higher than that in PBS with pH value of 7.4. Similarly, the release kinetics of Bovine serum albumin (BSA) showed higher release in an acidic system by the hydrogel composed of ZOP/CS. The hydrogel prepared by this study provided a good microenvironment for protein delivery. In summary, this composite polysaccharide hydrogel is a promising protein-drug-delivery material.
Honey Bee (Apis mellifera L.) Broods: Composition, Technology and Gastronomic Applicability
Authors: Guiné Raquel P. F. , Florença Sofia G. , Correia Paula M. R. , Anjos Ofélia , Coelho Catarina , Costa Cristina A.
Published: September 2022

Honey bee broods (larvae and pupae) can be consumed as human food, offering a rich nutritional value. Therefore, the objective of this work was to present an overview of the nutritional value of the honey bee brood and its gastronomic potential. The results indicated that honey bee broods are rich in protein (including essential amino acids), fat (essentially saturated and monounsaturated fatty acids), carbohydrates, vitamin C and those of the B complex, and minerals such as potassium, magnesium, calcium, and phosphorous. The results further highlight some variability according to the stage of development, with increasing content of fat and protein and decreasing carbohydrates from the larval to the pupal stages. The production of the honey bee brood in the hive, as well as its removal, can impact the wellbeing of the hive. This limits the production potential of the brood aimed at application for gastronomic purposes. The consumption and purchase of honey bee broods as food may be accessible in specialised markets where, for example, ethnic communities consume this type of food. However, in some markets, insects or products produced from insects are not readily accepted because of neophobia and disgust. The role of culinary chefs allied to traditional ways of preparing culinary dishes that include honey bee broods are relevant to motivate more people in western societies to consume of these types of food products.
Investigation on the Effects of a Pulsed Electric Field (PEF) Continuous System Implemented in an Industrial Olive Oil Plant
Authors: Leone Alessandro , Tamborrino Antonia , Esposto Sonia , Berardi Antonio , Servili Maurizio
Published: September 2022

The aim of this study was to investigate how the treatment of olive paste of the Picholine variety with pulsed electric fields (PEF) under real operating conditions in a large-scale olive oil extraction plant affects the extractability, chemical composition and sensory profile of the oils. The application of pulsed electric fields (PEF) as a non-thermal food processing technology is interesting for many food extraction processes. The results of this study show that pulsed electric fields can be used as a pretreatment before oil separation to increase the extractability of the process and improve the content of functional components. The application of pulsed electric field (PEF) treatment (2.4 kV/cm, 4 kJ/kg, 6 µs pulse width) to olive paste through a continuous system significantly increased the extractability and total concentration of phenols (especially oleuropein derivatives) compared to the control. In addition, the volatile compounds, α-tocopherol, the fatty acid profile and the main legal quality parameters of extra virgin olive oil (EVOO), including free acidity, peroxide values, extinction indices and sensory analysis, were evaluated. The pulsed electric fields (PEF) treatment did not modify these EVOO quality parameters, neither the α-tocopherol content nor the volatile profile. The sensory properties of EVOO were not affected as well as the PEF treatment showed a similar intensity of fruity and pungent attributes without any off-flavor according to the European Union legal standards. An increase in the bitter taste attribute was observed in the PEF oils. Consequently, this study demonstrates that pulsed electric fields (PEF) processing could be implemented in olive oil processing as pretreatment for improving the efficiency of the process.
Small Extracellular Vesicles of M1-BV2 Microglia Induce Neuronal PC12 Cells Apoptosis via the Competing Endogenous Mechanism of CircRNAs
Authors: Gao Sheng , Bai Luyue , Jia Shu , Meng Chunyang
Published: September 2022

Polarized microglia play a vital role in neurodegenerative diseases. However, the effects of polarized microglia-derived small extracellular vesicles (SEVs) on neuronal cells and the regulatory mechanisms of circular RNAs (circRNAs) in SEVs remain incompletely defined. In the present study, we carried out high-throughput sequencing and differential expression analysis of circRNAs in the SEVs of M0-phenotype BV2 microglia (M0-BV2) and polarized M1-phenotype BV2 microglia (M1-BV2). Hub circRNAs in the SEVs and their functions were screened using multiple bioinformatics methods. We further validated the effects of SEVs on neuronal PC12 cells by co-culturing M0-BV2 SEVs and M1-BV2 SEVs with neuronal PC12 cells. Among the differentially expressed circRNAs, the target mRNAs of six hub circRNAs (circ_0000705, circ_0001313, circ_0000229, circ_0001123, circ_0000621, and circ_0000735) were enriched in apoptosis-related biological processes. Furthermore, western blot and flow cytometry analysis demonstrated that M0-BV2 SEVs had no distinct effect on apoptosis of neuronal PC12 cells, while M1-BV2 SEVs remarkably increased the apoptosis of neuronal PC12 cells. We then constructed the competing endogenous RNA (ceRNA) networks of the six hub circRNAs. Taken together, the results suggest that polarized M1-BV2 microglia can induce apoptosis of neuronal PC12 cells through secreted SEVs, and this regulatory effect may be achieved by the circRNAs circ_0000705, circ_0001313, circ_0000229, circ_0001123, circ_0000621, and circ_0000735 through ceRNAs regulatory networks. These findings provide new potential targets for the treatment of neurodegenerative diseases.
Whole-Genome Profile of Greek Patients with Teratozοοspermia: Identification of Candidate Variants and Genes
Authors: Kyrgiafini Maria-Anna , Giannoulis Themistoklis , Chatziparasidou Alexia , Christoforidis Nikolaos , Mamuris Zissis
Published: September 2022

Male infertility is a global health problem that affects a large number of couples worldwide. It can be categorized into specific subtypes, including teratozoospermia. The present study aimed to identify new variants associated with teratozoospermia in the Greek population and to explore the role of genes on which these were identified. For this reason, whole-genome sequencing (WGS) was performed on normozoospermic and teratozoospermic individuals, and after selecting only variants found in teratozoospermic men, these were further prioritized using a wide range of tools, functional and predictive algorithms, etc. An average of 600,000 variants were identified, and of them, 61 were characterized as high impact and 153 as moderate impact. Many of these are mapped in genes previously associated with male infertility, yet others are related for the first time to teratozoospermia. Furthermore, pathway enrichment analysis and Gene ontology (GO) analyses revealed the important role of the extracellular matrix in teratozoospermia. Therefore, the present study confirms the contribution of genes studied in the past to male infertility and sheds light on new molecular mechanisms by providing a list of variants and candidate genes associated with teratozoospermia in the Greek population.
Perceptions, Knowledge and Attitudes among Young Adults about Prevention of HPV Infection and Immunization
Authors: Sidiropoulou Maria , Gerogianni Georgia , Kourti Freideriki Eleni , Pappa Despoina , Zartaloudi Afroditi , Koutelekos Ioannis , Dousis Evangelos , Margari Nikoletta , Mangoulia Polyxeni , Ferentinou Eftychia , Giga Anna , Zografakis-Sfakianakis Michail , Dafogianni Chrysoula
Published: September 2022

Introduction: Human papilloma virus (HPV) is one of the most common sexually transmitted infections and is widely known as the main causative agent for cervical cancer. The aim of this study was to investigate the perceptions, knowledge and attitudes of young Greek adults concerning prevention of HPV infection and HPV immunization. Material and Methods: This constitutes a cross-sectional online survey. A convenience sample of young Greek adults (n = 883) residing in Greece, aged 17 to more than 35 years was surveyed from December 2020 to March 2021. Two validated questionnaires were used to collect data. Results: Participants demonstrated moderate knowledge about HPV infection and vaccination, with a mean knowledge score of 53.26 (SD ± 20.65) and 38.92 (SD ± 17.58), respectively. Cronbach’s alpha value was 0.77 and 0.80. Female participants were better informed than males. Approximately 52.3% of respondents had been vaccinated and 65.5% were willing to get vaccinated in the future. Vaccination rate was significantly associated with gender (OR = 11.99; 99% CI = 6.59–21.84), knowledge about the HPV vaccine (OR = 1.04; 99% CI = 1.03–1.04) and age (OR = 0.07; 99% CI = 0.03–0.15). Reasons for vaccine refusal were insufficient information (36.8%) and fear of side effects (19%). Correlates of positive vaccination intention were knowledge about HPV (OR = 1.02; 99% CI = 1.01–1.02). Conclusions: The findings suggest that the Greek government’s continuing HPV promotion efforts and education on the risks of HPV infection among young people are likely to increase vaccination acceptance among this group.
Validation of Operational Definition to Identify Patients with Osteoporotic Hip Fractures in Administrative Claims Data
Authors: Lee Young-Kyun , Yoo Jun-Il , Kim Tae-Young , Ha Yong-Chan , Koo Kyung-Hoi , Choi Hangseok , Lee Seung-Mi , Suh Dong-Churl
Published: September 2022

As incidences of osteoporotic hip fractures (OHFs) have increased, identifying OHFs has become important to establishing the medical guidelines for their management. This study was conducted to develop an operational definition to identify patients with OHFs using two diagnosis codes and eight procedure codes from health insurance claims data and to assess the operational definition’s validity through a chart review. The study extracted data on OHFs from 522 patients who underwent hip surgeries based on diagnosis codes. Orthopedic surgeons then reviewed these patients’ medical records and radiographs to identify those with true OHFs. The validities of nine different algorithms of operational definitions, developed using a combination of three levels of diagnosis codes and eight procedure codes, were assessed using various statistics. The developed operational definition showed an accuracy above 0.97 and an area under the receiver operating characteristic curve above 0.97, indicating excellent discriminative power. This study demonstrated that the operational definition that combines diagnosis and procedure codes shows a high validity in detecting OHFs and can be used as a valid tool to detect OHFs from big health claims data.
“Degrees of Freedom”: Comparing Mental Distress of Populations with Different Levels of Access to Care-Prisoners, Psychiatric Patients and General Population
Authors: Nagar Maayan
Published: September 2022

Objectives: The study presents an analysis of the risk for common mental disorders (CMDs) in populations with different levels of access to mental health care. Methods: We merged and statistically compared the representative data of prisoners to data collected from psychiatric clinics and the general population. Participants across all samples completed the General Health Questionnaire. Results: More than half of the inmates met the criteria for CMDs, while rates were 25% in the general population and 80% among psychiatric patients. The odds of prisoners being five times more likely to meet the criteria for CMDs were five times higher than the odds of the general population while controlling for demographic variables. Conclusions: The study highlights the need for prisoners for mental health services. Prisoners face stressful life conditions before and during incarceration while having limited access to medical and psychological treatment stresses the need for systemic interventions.
Knowledge, Attitudes, and Behaviors towards Proper Nutrition and Lifestyles in Italian Diabetic Patients during the COVID-19 Pandemic
Authors: Arghittu Antonella , Deiana Giovanna , Castiglia Elena , Pacifico Adolfo , Brizzi Patrizia , Cossu Andrea , Castiglia Paolo , Dettori Marco
Published: September 2022

Prevention of diabetes mellitus is mainly based on a healthy lifestyle. The lockdown measures imposed during the COVID-19 pandemic resulted in major changes in daily life and social behavior, which may have an influence on diabetes self-management and glycemic control. The present work aims to assess the relationship between diabetic patients’ knowledge, attitudes, and behaviors towards proper nutrition and lifestyles in order to plan strategies for educational intervention from a health literacy perspective. Attitudes, behaviors, and knowledge of diabetic patients attending the Diabetes and Metabolic Diseases Department of the Local Health Authority of Sassari (ASL1-SS) were assessed with a cognitive survey conducted from April to July 2022. Three hundred twenty-one questionnaires were administered during the survey period. Fifty-two percent of diabetic patients were female and 48% male, with a mean age of 61.1 ± 18.5 years and 62.0 ± 15.1 years, respectively. The overall level of knowledge about the role of food and proper nutrition with respect to the risk of diabetes and its complications appeared to be generally unsatisfactory and inadequate. Nonetheless, females showed a significantly higher level of knowledge than males (p < 0.0001). Moreover, knowledge was seen to decrease according to the age of the patients (p = 0.035). As for the possible impact played by the COVID-19 pandemic on lifestyles, it should be noted that about 70% of the respondents stated that they had maintained a reasonable dietary standard or even improved it throughout. Thus, the study underlines the need to improve the knowledge of diabetic subjects about nutrition and, in particular, their self-management, positively influencing behaviors and attitudes.
Prevalence of Low Back Pain and Associated Risk Factors among Saudi Arabian Adolescents: A Cross-Sectional Study
Authors: Alhowimel Ahmed S. , Alfaifi Reem M. , Alluhaybi Abdulkarim A. , Alanazi Majed A. , Alanazi Khalid M. , Almathami Nouf S. , Almedhwah Sarah H. , Almuayli Abdullah A. , Alenazi Aqeel M. , Alshehri Mohammed M. , Alqahtani Bader A. , Alodaibi Faris
Published: September 2022

Low back pain is the most prevalent musculoskeletal condition. Studies on adolescent low back pain are scarce, with no research to determine its prevalence in Saudi Arabia. This study aimed to assess the prevalence and associated risk factors of low back pain in Saudi Arabian adolescents. This cross-sectional study was conducted among Saudi Arabian high school students, which included demographic data, medical and low back pain history. The completed survey by 2000 participants showcased 57.9% of students experiencing low back pain in the last 12 months. This included 31.2% men and 26.7% women. This study found a link between low back pain and age, clinical symptoms of diabetes, heart disease, lung disease, thyroid disease, arthritis, and back surgery, a family history of low back pain, as well as smoking. There is substantial prevalence of low back pain in Saudi Arabian adolescents. This study identified several modifiable and non-modifiable risk factors stemming from adolescent low back pain.
From Fragmentation to Intensification: Land Reform in China’s “New Era”
Authors: Wang Qiang , Yu Liying , Yang Yueling
Published: September 2022

Combining the current national conditions of China and the status quo of rural land, realizing the transformation of land from fragmentation to intensification is the only way for China to move towards agricultural modernization. We selected Feicheng City, Shandong Province, as the research area, conducted regression analysis on the data by means of questionnaires and key interviews, and identified the influencing factors that can affect and change farmers’ willingness to transfer (WTT) their land and willingness to the duration (WTD) of land transfer. The study found that 82.54% of farmers are willing to transfer land, and the WTD is 9.34 years. Among them, five factors, including job stability, purchased houses in urban area, cultivated land roads, degree of policy understanding, and emotion for the land, can significantly affect the farmers’ WTT. Six factors, namely, age, job stability, number of family members, purchased houses in urban area, non-agricultural income, emotion for the land, can significantly affect the farmers’ WTD. Based on this, we propose the “MPEU theory” of farmers’ land transfer. That is, by allowing farmers to change their minds, understand policies, increase the non-agricultural employment rate, and improve the level of urbanization, the farmers’ WTT/WTD can be improved, and the level of land intensification can be improved. Finally, agricultural modernization, peasant citizenization, and rural urbanization will be realized.
Opening up Neat New Things: Exploring Understandings and Experiences of Social and Emotional Learning and Meaningful Physical Education Utilizing Democratic and Reflective Pedagogies
Authors: Howley Donal , Dyson Ben , Baek Seunghyun , Fowler Judy , Shen Yanhua
Published: September 2022

When it comes to teaching social and affective outcomes pertaining to health and physical activity within Physical Education (PE) settings, such learning historically has been observed as manifesting itself as hoped-for-by-products rather than intentionally-taught-for curricular outcomes. The purpose of this study was to explore understandings and experiences of Social and Emotional Learning (SEL) and Meaningful Physical Education (MPE) utilizing democratic and reflective pedagogies. A qualitative case study design was implemented in an alternative high school setting in the USA across 10 months. Participants included the Teacher–Researcher (TR), one Physical Education (PE) teacher, a critical friend, two teaching assistants, and 16 ninth-grade alternative high school students aged 14–15 (eight girls/eight boys). Methods involved a TR journal, post–lesson teaching reflections, interviews, and focus groups, with inductive and deductive analysis applied. The following themes were constructed: It really made you think; making movement meaningful; being a better classmate; and doing things differently. Results demonstrate how utilizing democratic and reflective approaches grounded in social constructivist learning theory innovatively promoted SEL and MPE. It allowed students to reflect, interrogate and discuss how movement experiences inside and outside of PE influenced their pursuit of a physically active life. Participants articulated experiencing a more inclusive learning experience that challenged the purpose and subject matter of previous PE and physical activity. Teaching for SEL and MPE using common language and terminology around pre–identified and defined competencies, skills, and features drawn from these conceptual frameworks as demonstrated here, can help contribute to more concrete and uniform learning experiences within and across settings. Doing so led participants to demonstrate more holistic and broader understandings of what constituted participation in PE and physical activity, as well as how to promote and participate in meaningful movement and physical activity within and outside of school to promote healthy living. We call for further embedding of democratic and reflective pedagogies in PE teacher education and professional development that provides teachers and students with the opportunity to do so going forward.
So Far, So Close: Identification with Proximal and Distal Groups as a Resource in Dealing with the COVID-19 Pandemic
Authors: Graziani Anna Rita , Botindari Lucia , Menegatti Michela , Moscatelli Silvia
Published: September 2022

A robust body of research has highlighted the fundamental role of social identifications in dealing with emergencies and in predicting commitment behaviors. We report the results of two studies carried out in Italy to assess whether the subjective sense of belonging to meaningful proximal and distal social groups affected people’s ability to cope with the pandemic crisis. Study 1 (N = 846) shows that different identifications with proximal (i.e., family and friends) and distal social groups (i.e., nation, European, and humankind) may act as buffers for individuals by reducing negative emotions and negative expectations about the future after COVID-19 and by increasing people’s intentions to adhere to containment measures and to be involved in prosocial actions. Study 2 (N = 350) highlights the role of European identification in predicting propensities for using the tracing app and getting vaccinated. These results confirm the benefits of various types of identification (proximal vs. distant) in helping individuals deal with the COVID-19 pandemic.