bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental and Numerical Study on the Influence of Stress Concentration on the Flexural Stability of an Aluminium Hollow Tube
Authors: Radhakrishnan Ganesh , Breaz Daniel , Al Khusaibi Sami Sulaiman , Al Subaihi Amjad Juma , Al Ismaili Al Azhar Zahir , AlMaani AlSalt Malik , Karthikeyan Kadhavoor R.
Published: February 2023

In recent times, particularly in applications used to build various structures for construction purposes or machines, solid sections have been gradually replaced by hollow sections due to their attractive features such as being light weight and having high specific strength. In the present investigation, an attempt was made to investigate, in detail, the flexural capability of aluminium hollow tubes (AHTs) with square cross-sections. The objective of the investigation was to study the influence of stress concentration on the flexural behaviour of the hollow tube. The stress concentration factor considered in this investigation was holes of various cross-sections and quantities. Three-point bending tests with concentrated loads were conducted on specimens of a hollow tube with different stress concentrations such as circular holes, multiple circular holes, square holes and perforations. The load was applied manually during the bending test with appropriate increments. The bending test was carried out on specimens with support spans of 110, 130, 170 and 200 mm. The output measures of the study were maximum bending load, deflection and flexural stiffness. The output measures were analysed in detail in order to recommend the type and nature of stress concentration in a hollow tube applied to structural applications to ensure the safest workability. The flexural stability of the tube was analysed by experimental and numerical procedures, and the results were validated using an analytical approach. It was found that the results of all the approaches complement each other with a low significance of error. AHTs with a circular hole, multiple circular holes and perforations were observed to have better flexural stability than other AHTs such as AHTs with square hole and plain AHTs.
Technological Aspects of Variation in Process Characteristics and Tool Condition in Grinding Process Diagnostics
Authors: Kacalak Wojciech , Lipiński Dariusz , Szafraniec Filip , Wieczorowski Michał , Twardowski Paweł
Published: February 2023

The article presents the technological aspects of the diagnostics of grinding processes. The main features of the grinding process and their importance in diagnostic issues are discussed. Selected issues of research and assessment of the condition of the active surface of grinding wheels are presented. The authors pointed out that the parameters used to assess the topography of the ground surfaces do not have sufficient possibilities to differentiate the surface condition of the grinding wheels. This publication draws attention to the possibility of using new dedicated parameters to assess the properties of the grinding wheel surface. These parameters have a high ability to differentiate changes occurring as a result of the abrasion of grain vertices, their chipping or loading of the grinding wheel surface. The methodology of assessing the processes of abrasive grain wear and changes in the shape and dimensions of the grinding wheel, taking into account the probabilistic features of the grinding process, was formulated. The directions for the development of abrasive tools are presented, pointing to hybrid tools with a multi-phase structure, modified by additions of abrasive aggregates. A new research direction has also been formulated on the use of additive technology to produce specialised abrasive tools, including those with built-in process sensors.
Thermally Assisted Optically Stimulated Luminescence (TA-OSL) from Commercial BeO Dosimeters
Authors: Polymeris Georgios S.
Published: February 2023

BeO is another luminescent phosphor with very deep traps (VDTs) in its matrix that could not be stimulated using either thermal or conventional optical stimulations. The present study attempts to stimulate these traps using thermally assisted optically stimulated luminescence (TA-OSL), a combination of simultaneous thermal and optical stimulation that is applied to the material following a thermoluminescence measurement up to 500 °C. An intense, peak-shaped TA-OSL signal is measured throughout the entire temperature range between room temperature and 270 °C. This signal can be explained as the transfer of charges from VDTs to both dosimetric TL traps. Experimental features such as the peaked shape of the signal along with the presence of residual TL after the TA-OSL suggest that recombination of TA-OSL takes place via the conduction band. Isothermal TA-OSL is not effective for extending the maximum detection dose thresholds of BeO, unlike minerals such as quartz and aluminum oxide. Nevertheless, TA-OSL could be effectively used in order to either (a) control the occupancy of VDTs, circumventing the intense sensitivity changes induced by long-term uses and high accumulated dose to the VDTs, or (b) measure the total dose accumulated over a series of repetitive dose calculations.
Microwave Imaging Approach for Breast Cancer Detection Using a Tapered Slot Antenna Loaded with Parasitic Components
Authors: Zerrad Fatima-ezzahra , Taouzari Mohamed , Makroum El Mostafa , Aoufi Jamal El , Qanadli Salah D. , Karaaslan Muharrem , Al-Gburi Ahmed Jamal Abdullah , Zakaria Zahriladha
Published: February 2023

In this paper, a wideband antenna is proposed for ultra-wideband microwave imaging applications. The antenna is comprised of a tapered slot ground, a rectangular slotted patch and four star-shaped parasitic components. The added slotted patch is shown to be effective in improving the bandwidth and gain. The proposed antenna system provides a realized gain of 6 dBi, an efficiency of around 80% on the radiation bandwidth, and a wide impedance bandwidth (S11 < −10 dB) of 6.3 GHz (from 3.8 to 10.1 GHz). This supports a true wideband operation. Furthermore, the fidelity factor for face-to-face (FtF) direction is 91.6%, and for side by side (SbS) is 91.2%. This proves the excellent directionality and less signal distortion of the designed antenna. These high figures establish the potential use of the proposed antenna for imaging. A heterogeneous breast phantom with dielectric characteristics identical to actual breast tissue with the presence of tumors was constructed for experimental validation. An antenna array of the proposed antenna element was situated over an artificial breast to collect reflected and transmitted waves for tumor characterization. Finally, an imaging algorithm was used to process the retrieved data to recreate the image in order to detect the undesirable tumor object inside the breast phantom.
Precision Machining by Dicing Blades: A Systematic Review
Authors: Yuan Zewei , Riaz Ali , Chohan Bilal shabbir
Published: February 2023

Diamond dicing blades are profound cutting tools that find their applications in semiconductor back-end packaging and assembly processes. To fully appreciate the benefits of the dicing blade technique for precision machining, a deeper understanding is required. This paper systematically reviews the contribution of dicing blades in machining, followed by the context of dicing blades: production, characterization, methodology, and optimization. The readers are enlightened about the potential prospects that can be exploited for precision spectra as a result of current research and engineering developments.
Quasi-Coordinates-Based Closed-Form Dynamic Modeling and Analysis for a 2R1T PKM with a Rigid–Flexible Structure
Authors: Zhu Renfeng , Yang Guilin , Fang Zaojun , Chen Chin-Yin , Li Huamin , Zhang Chi
Published: February 2023

This work derives a closed-form dynamic model for a two rotational and one translational degrees-of-freedom (2R1T) parallel kinematic mechanism (PKM) with a hybrid rigid–flexible structure for force-control applications. Based on the three-prismatic-prismatic-spherical (3PPS) kinematic configuration of the 2R1T PKM and its zero-torsion motion characteristics, a symbolic formulation approach is proposed to establish closed-form kinematic models for both forward and inverse kinematics analysis. As the moving platform pose of the 2R1T 3PPS PKM can be readily determined by the three active prismatic joint variables and the three passive prismatic joint variables, these six joint variables are selected as the quasi-coordinates so as to systematically develop the closed-form dynamic model with a Lagrangian formulation, in which the stiffness and deformation of the three flexure-based passive prismatic joints are uniformly taken into consideration. Through eliminating the three passive prismatic joint variables based on the principle of virtual work and the relationships between the active and passive prismatic joint variables, a closed-form dynamic model for the 2R1T 3PPS PKM with a rigid–flexible structure is finally obtained. The correctness of the closed-form dynamic model was validated with the commercial dynamic simulation software. Utilizing the closed-form dynamic model, the effects of different flexure stiffness in driving directions on the required active joint force were investigated, which indicated that little flexure stiffness in driving directions is desired.
Hard Milling Process Based on Compressed Cold Air-Cooling Using Vortex Tube for Sustainable and Smart Manufacturing
Authors: Celent Luka , Bajić Dražen , Jozić Sonja , Mladineo Marko
Published: February 2023

Improving machining performance and meeting the requirements of sustainable production at the same time represents a major challenge for the metalworking industry and scientific community. One approach to satisfying the above challenge is to apply different types of cutting fluids or to optimise their usage during the machining process. The fact that cutting fluids are well known as significant environmental pollutants in the metalworking industry has encouraged researchers to discover new environmentally friendly ways of cooling and lubricating in the machining process. Therefore, the main goal is to investigate the influence of different machining conditions on the efficiency of hard machining and find a sustainable solution towards smart manufacturing. In the experimental part of the work, the influence of various machining parameters and conditions on the efficiency of the process was investigated and measured through the surface roughness, tool wear and cutting force components. Statistical data processing was carried out, and predictive mathematical models were developed. An important achievement is the knowledge of the efficiency of compressed cold air cooling for hard milling with the resulting lowest average flank wear of 0.05 mm, average surface roughness of 0.28 µm, which corresponds to grinding procedure roughness classes of N4 and N5, and average tool durability increase of 26% compared to dry cutting and conventional use of cutting fluids. Becoming a smart machining system was assured via technological improvement achieved through the reliable prediction of tool wear obtained by radial basis neural networks modelling, with a relative prediction error of 3.97%.
Design of a High-Gap Plant Protection Machine (HGPM) with Stepless Variable Speed and Power Adjustable Function
Authors: Cai Zengbin , Xie Dongbo , Liu Tao , Hu Peiyu , Liu Hongji , Zheng Quan
Published: February 2023

The passing performance and driving stability performance of HGPM in an unstructured environment will directly affect the quality of HGPM operation. This paper designs an HGPM power chassis transmission system in order to address the problem of poor adaptability of existing plant protection machines to complex working conditions in the field, especially in the middle and late stage of plant protection operation of tall crops, which cannot pass smoothly due to the obstruction of vision and special road conditions resulting in insufficient traction of the whole machine. The system is theoretically analyzed based on hydrostatic transmission and a time-sharing four-wheel drive splitter; then, based on Solidworks and RecurDyn software, the HGPM is modeled in three dimensions, and the dynamic simulation of working conditions such as climbing, crossing the ridge, and opening the road during field operation is carried out. The simulation results show that the 2H mode can climb over a slope with an angle in the range of 0−25° and a ridge with height in the range of 0−100 mm, the 4H mode can climb over a slope with an angle in the range of 0−35° and a ridge with height in the range of 0−320 mm, with relatively stable body speed and the wheel rotation angular speed converging faster under the open road condition. Finally, prototype performance tests were conducted. The test results show that 4H mode can smoothly pass the ridge with a ridge height of 320 mm and a slope of 26°, while 2H mode has a sharp drop in speed to 0 after a short fluctuation. 4H mode achieves a more rapid convergence of longitudinal wheel stability compared to 2H mode. The developed chassis drive system of a new type of HGPM meets the design requirements and provides a reference for the dynamic chassis design of HGPM.
Vibronic Relaxation Pathways in Molecular Spin Qubit Na9[Ho(W5O18)2]·35H2O under Pressure
Authors: Musfeldt Janice L. , Liu Zhenxian , López-Alcalá Diego , Duan Yan , Gaita-Ariño Alejandro , Baldoví José J. , Coronado Eugenio
Published: February 2023

In order to explore how spectral sparsity and vibronic decoherence pathways can be controlled in a model qubit system with atomic clock transitions, we combined diamond anvil cell techniques with synchrotron-based far infrared spectroscopy and first-principles calculations to reveal the vibrational response of Na9[Ho(W5O18)2]·35H2O under compression. Because the hole in the phonon density of states acts to reduce the overlap between the phonons and f manifold excitations in this system, we postulated that pressure might move the HoO4 rocking, bending, and asymmetric stretching modes that couple with the MJ = ±5, ±2, and ±7 levels out of resonance, reducing their interactions and minimizing decoherence processes, while a potentially beneficial strategy for some molecular qubits, pressure slightly hardens the phonons in Na9[Ho(W5O18)2]·35H2O and systematically fills in the transparency window in the phonon response. The net result is that the vibrational spectrum becomes less sparse and the overlap with the various MJ levels of the Ho3+ ion actually increases. These findings suggest that negative pressure, achieved using chemical means or elongational strain, could further open the transparency window in this rare earth-containing spin qubit system, thus paving the way for the use of device surfaces and interface elongational/compressive strains to better manage decoherence pathways.
Multiperson Decision-Making Using Consistent Interval-Valued Fuzzy Information with Application in Supplier Selection
Authors: Yu Xiaodong , Rehman Atiq ur , Ashraf Samina , Hussain Muhammad , Faizi Shahzad
Published: February 2023

This study describes a consistency-based approach for multiperson decision-making (MPDM) in which decision-makers’ suggestions are expressed as incomplete interval-valued fuzzy preference relations. The presented approach utilizes Lukasiewicz’s t-norm in conjunction with additive reciprocity to obtain comprehensive interval valued fuzzy preference relations from each expert, and the transitive closure formula also produces L-consistency. We would evaluate the consistency weights of the experts using consistency analysis. Experts are allocated final priority weights by combining the consistency weights and preset weights. A collective consistency matrix is then constructed from the weighted sum of preference matrices. After computing the possibility degrees, the normalization procedure is utilized to generate complimentary matrices, and the final ranking values of alternatives are derived as well. Finally, a numerical example demonstrates the efficacy of the suggested approach following a comparison analysis.
Determining Unintentional Island Threshold to Enhance the Reliability in an Electrical Distribution Grid
Authors: Arefin Ahmed Amirul , Rahman Md. Siddikur , Hossain Lipu Molla Shahadat , Sarker Mahidur R. , Sawaran Singh Narinderjit Singh , Meraj Sheikh Tanzim
Published: February 2023

Due to the significant number of distributed generators in the electric power system, islanding detection requirements are becoming an increasingly prominent aspect of the power system. The island detection system depends on accurate threshold determination since an incorrect threshold might result in a hazardous situation. To evaluate the proposed method’s capacity to discriminate between different events, this study examined different unintentional islanding conditions such as under frequency and over frequency. The purpose of this study is to establish the threshold of the under and over frequency island conditions. The under frequency island condition happens when the distributed generator (DG) capacity exceeds the amount of connected load; on the other hand, the over frequency island condition happens during a higher connected load compared to the capacity of the DG. The contribution of this research is to propose an unintentional island threshold setting technique based on bus voltage angle difference data of the phasor measurement unit (PMU). In the PowerWorld simulator, the Utility Kerteh (location: Terengganu, Malaysia) bus system has been designed and simulated in this work. The test system has four distinct islanding scenarios under two conditions, and the performance of the proposed methods demonstrates that for the under frequency islanding conditions the scenario’s threshold can be taken at a minimum of 40 milliseconds (ms) and a maximum of 60 ms, while the over frequency condition island threshold can be placed at a minimum of 60 ms and a maximum of 80 ms depending on the scenarios. Therefore, the proposed technique will be contributed to increase the reliability of the overall distribution grid so the unintentional island can be detected faster in terms of time.
Generalizations of Higher-Order Duality for Multiple Objective Nonlinear Programming under the Generalizations of Type-I Functions
Authors: Kassem Mohamed Abd El-Hady , Alshanbari Huda M.
Published: February 2023

In this study, we introduce new generalizations of higher-order type-I functions and higher-order pseudo-convexity type-I functions. The application of the notion of sublinear functionals to these generalizations of higher-order type-I and higher-order pseudo-convexity type-I functions is crucial to our main findings. Furthermore, under these generalizations of the higher-order type-I and higher-order pseudo-convexity type-I functions, we established and studied six new types of higher-order duality models and programs for multiple objective nonlinear programming problems. In addition, we use these generalizations of higher-order type-I functions and higher-order pseudo-convexity type-I functions, to formulate and prove the theorems of weak duality, strong duality, and strict converse duality for these new six types of higher-order model programs.
On Cyclic Contractive Mappings of Kannan and Chatterjea Type in Generalized Metric Spaces
Authors: Al-Khaleel Mohammad , Al-Sharif Sharifa , AlAhmad Rami
Published: February 2023

Novel cyclic contractions of the Kannan and Chatterjea type are presented in this study. With the aid of these brand-new contractions, new results for the existence and uniqueness of fixed points in the setting of complete generalized metric space have been established. Importantly, the results are generalizations and extensions of fixed point theorems by Chatterjea and Kannan and their cyclical expansions that are found in the literature. Additionally, several of the existing results on fixed points in generalized metric space will be generalized by the results presented in this work. Interestingly, the findings have a variety of applications in engineering and sciences. Examples have been given at the end to show the reliability of the demonstrated results.
A Novel Method for Generating the M-Tri-Basis of an Ordered Γ-Semigroup
Authors: Palanikumar M. , Jana Chiranjibe , Al-Shanqiti Omaima , Pal Madhumangal
Published: February 2023

In this paper, we discuss the hypothesis that an ordered Γ-semigroup can be constructed on the M-left(right)-tri-basis. In order to generalize the left(right)-tri-basis using Γ-semigroups and ordered semigroups, we examined M-tri-ideals from a purely algebraic standpoint. We also present the form of the M-tri-ideal generator. We investigated the M-left(right)-tri-ideal using the ordered Γ-semigroup. In order to obtain their properties, we used M-left(right)-tri-basis. It was possible to generate a M-left(right)-tri-basis from elements and their subsets. Throughout this paper, we will present an interesting example of order ⪯mlt(⪯mrt), which is not a partial order of S. Additionally, we introduce the notion of quasi-order. As an example, we demonstrate the relationship between M-left(right)-tri-basis and partial order.
Paid Access to Information Promotes the Emergence of Cooperation in the Spatial Prisoner’s Dilemma
Authors: Niu Haodong , Li Keyu , Wang Juan
Published: February 2023

In biological evolution, organisms that are more adapted to the environment tend to survive better, which can be explained in part by evolutionary game theory. In this paper, we propose an improved spatial prisoner’s dilemma game model, which allows the focal player to access the strategy of other agents beyond their nearest neighbors with a specified probability. During the strategy update, a focal player usually picks up a randomly chosen neighbor according to a Fermi-like rule. However, in our model, unlike the traditional strategy imitation, a focal agent will decide to update their strategy through the modified rule with a specific probability q. In this case, the focal agent accesses n other individuals who have the same strategy as the imitated neighbor, where the information accessing cost needs to be paid, and then compares their discounted payoff with the average payoff of those n+1 agents to make the decision of strategy adoption; otherwise, they only refer to their own payoff and their neighbor’s payoff to decide whether the strategy spread happens. Numerical simulations indicate that a moderate value of n can foster the evolution of cooperation very well, and increase in q will also improve the dilemma of cooperators. In addition, there exists an optimal product of n×c to cause the emergence of cooperation under the specific simulation setup. Taken together, the current results are conducive to understanding the evolution of cooperation within a structured population.
Research on Multi-Objective Optimal Scheduling for Power Battery Reverse Supply Chain
Authors: Tan Kangye , Tian Yihui , Xu Fang , Li Chunsheng
Published: February 2023

In the context of carbon neutralization, the electric vehicle and energy storage market is growing rapidly. As a result, battery recycling is an important work with the consideration of the advent of battery retirement and resource constraints, environmental factors, resource regional constraints, and price factors. Based on the theoretical research of intelligent algorithm and mathematical models, an integer programming model of urban power battery reverse supply chain scheduling was established with the goal of the highest customer satisfaction and the least total cost of logistics and distribution, to study the influence of the resources and operation status of a built city recycling center and dismantling center on the power battery reverse supply chain. The model includes vehicle load, customer demand point satisfaction range, and service capacity constraints. This study collected regional image data, conducted image analysis, and further designed an improved Non-dominated Sorting Genetic Algorithm-II (NSGA-II) optimization algorithm suitable to solve the global optimization problem by introducing the improvement strategy of convergence rate, particle search, and the traditional elite individual retention. The results verified the practicability of the model, the global optimization ability of the algorithm to solve the problem, and the operation speed through comparing the results obtained from the basic algorithm. A reasonable comprehensive solution for the location and path optimization of the urban recycling center was also obtained. Multi-objective optimization was carried out in vehicle scheduling, facility construction, and customer satisfaction construction. The basic algorithm and integrated optimization software were compared. We found that the model and the scheme provided by the algorithm can significantly reduce the operation cost of the enterprise. This research provided new insights for enterprises to effectively utilize resources and optimize the reverse supply chain scheduling of an urban power battery.
Cash Flow Optimization on Insurance: An Application of Fixed-Point Theory
Authors: Zhong Yangmin , Huang Huaping
Published: February 2023

The purpose of this paper is to explore a discrete-time cash flow optimization problem of the insurance company with time value of ruin under different interest rates. For the sake of considering the time value of ruin, we assume that the shareholders can get subsidies per unit time, as long as the insurance company is not bankrupt. The switching of different interest rates on the market is controlled by a stationary Markov chain. The dynamic programming principle is used to solve this optimization problem. By using the method of fixed-point theory, we show that the value function is the unique solution of the dynamic programming equation and a numerical algorithm is proposed to solve the value function as well as the optimal policy. Furthermore, two examples are revealed to illustrate the application of the main results obtained in the presented paper.
A Novel Hybrid Deep Neural Network for Predicting Athlete Performance Using Dynamic Brain Waves
Authors: Tsai Yu-Hung , Wu Sheng-Kuang , Yu Shyr-Shen , Tsai Meng-Hsiun
Published: February 2023

The exploration of the performance of elite athletes by cognitive neuroscience as a research method has become an emerging field of study in recent years. In the research of cognitive abilities and athletic performance of elite athletes, the tasks of an experiment are usually performed by athletics task of closed skills rather than open skills. Thus, little has been conducted to explore the cognitive abilities and athletic performance of elite athletes with open skills. This study is novel as it attempts at predicting how table tennis athletes perform by collecting their dynamic brain waves when executing specific plays of table tennis, and then putting the data of dynamic brain waves to deep neural network algorithms. The method of this study begins with the collection of data on the dynamic brain waves of table tennis athletes and then converts the time domain data into frequency domain data before improving the accuracy of categorization using a hybrid convolutional neural networks (CNN) framework of deep learning. The findings hereof were that the algorithm of hybrid deep neural networks proposed herein was able to predict the sports performance of athletes from their dynamic brain waves with an accuracy up to 96.70%. This study contributes to the literature in cognitive neuroscience on dynamic brain waves in open skills and creates a novel hybrid deep CNN classification model for identifying dynamic brain waves associated with good elite sports performance.
Phytochemical Investigation of Three Cystoseira Species and Their Larvicidal Activity Supported with In Silico Studies
Authors: Aly Shaza H. , Elissawy Ahmed M. , Salah Dina , Alfuhaid Nawal Abdulaziz , Zyaan Ola H. , Mohamed Hany I. , Singab Abdel Nasser B. , Farag Shaimaa M.
Published: February 2023

Culex pipiens mosquitoes are transmitters of many viruses and are associated with the transmission of many diseases, such as filariasis and avian malaria, that have a high rate of mortality. The current study draws attention to the larvicidal efficacy of three methanolic algal extracts, Cystoseira myrica, C. trinodis, and C. tamariscifolia, against the third larval instar of Cx. pipiens. The UPLC-ESI-MS analysis of three methanol fractions of algal samples led to the tentative characterization of twelve compounds with different percentages among the three samples belonging to phenolics and terpenoids. Probit analysis was used to calculate the lethal concentrations (LC50 and LC90). The highest level of toxicity was attained after treatment with C. myrica extract using a lethal concentration 50 (LC50) of 105.06 ppm, followed by C. trinodis (135.08 ppm), and the lowest level of toxicity was achieved by C. tamariscifolia (138.71 ppm) after 24 h. The elevation of glutathione-S-transferase (GST) and reduction of acetylcholine esterase (AChE) enzymes confirm the larvicidal activity of the three algal extracts. When compared to untreated larvae, all evaluated extracts revealed a significant reduction in protein, lipid, and carbohydrate contents, verifying their larvicidal effectiveness. To further support the observed activity, an in silico study for the identified compounds was carried out on the two tested enzymes. Results showed that the identified compounds and the tested enzymes had excellent binding affinities for each other. Overall, the current work suggests that the three algal extractions are a prospective source for the development of innovative, environmentally friendly larvicides.
A Rare Triploid Involving the Coexistence of Glioblastoma Multiforme, Arteriovenous Malformation and Intracranial Aneurysm: Illustrative Case and Literature Review
Authors: Li Chi-Ruei , Chen Se-Yi , Yang Meng-Yin , Cheng Wen-Yu , Shen Chiung-Chyi
Published: February 2023

The coexistence of glioblastoma multiforme (GBM) and arteriovenous malformation (AVM) is rarely reported in the literature. According to the present literature, these GBM or glioma-related vascular malformations may present simultaneously in distinct regions of the brain or occur in the same area but at different times. So far, these distinct hypervascular glioblastomas have been described but are not classified as a separate pathological entities. Considering their heterogeneity and complexity, all the above mentioned cases remain challenging in diagnosis and therapeutic modality. Likewise, there is a paucity of data surrounding the simultaneous presentation of GBM with intracranial aneurysms. In the literature, the independent concurrence of these three intracranial lesions has never been reported. In this article, we present a case who suffered from intermittent headaches and dizziness initially and further radiographic examination revealed an internal carotid artery (ICA) aneurysm that occurred in the patient with coexisting GBM and AVM. Surgical intervention for tumor and AVM removal was performed smoothly. This patient underwent endovascular coiling for the ICA aneurysm 4 months postoperatively. In addition, we also review the current literature relating to this rare combination of medical conditions.
ADHD Follow-Up in Adulthood among Subjects Treated for the Disorder in a Child and Adolescent Mental Health Service from 1995 to 2015
Authors: Di Lorenzo Rosaria , Balducci Jessica , Cutino Anna , Latella Emanuela , Venturi Giulia , Rovesti Sergio , Filippini Tommaso , Ferri Paola
Published: February 2023

Background and Objectives: ADHD is a neurodevelopmental disorder characterized by inattention and hyperactivity/impulsivity and can persist in adulthood. The aim of this study is to deepen knowledge about adult ADHD follow-up. Materials and Methods: This observational study consists of one retrospective part aimed at collecting records of children and adolescents treated for ADHD in the Children and Adolescent Mental Health Service (CAMHS) from 1995 to 2015 and, successively, at identifying their adult follow-up in Adult Mental Health Service (AMHS); the second part consists of ADHD scale administration, Diagnostic Interview for ADHD in Adults (DIVA 2-0) and Adult Self Rating Scale (ASRSv1.1), for the subjects currently being treated at AMHS who agreed to participate in the study. Results: We observed that among the 55 patients treated at CAMHS between 1995 and 2015 for ADHD and subsequently at the AMHS, none presented a diagnosis of ADHD; instead, they were treated for Intellectual Dysfunction (33%), Borderline Personality Disorder (15%) and Anxiety Disorders (9%), and two individuals were also diagnosed with comorbid substance/alcohol abuse (4%). Of the 55 patients, only 25 (45%) were treated at AMHS during the study period. Though we asked for their informed consent to administer the questionnaires, we were able to test only seven patients. The ASRS-V1.1 score showed that 43% of patients reported symptoms of ADHD persistence in adulthood. For DIVA 2.0, 57% of individuals reported scores indicating the persistence of the ADHD inattention component, and 43% the persistence of both ADHD dimensions. Conclusions: ADHD cannot be considered a disorder confined to childhood/adolescence but instead is a chronic and complex condition that can persist into adulthood. The very small size of our final sample may account for both the high ADHD dropout rate over the long follow-up period and the difficult transition from child to adult health care in ADHD treatment. Our investigation suggests the need for specific training in the diagnosis and treatment of adult ADHD and the implementation of transition protocols between minor and adult services to improve long-term treatments.
Chronic Stress Induces Type 2b Skeletal Muscle Atrophy via the Inhibition of mTORC1 Signaling in Mice
Authors: Fushimi Shigeko , Nohno Tsutomu , Katsuyama Hironobu
Published: February 2023

Chronic stress induces psychological and physiological changes that may have negative sequelae for health and well-being. In this study, the skeletal muscles of male C57BL/6 mice subjected to repetitive water-immersion restraint stress to model chronic stress were examined. In chronically stressed mice, serum corticosterone levels significantly increased, whereas thymus volume and bone mineral density decreased. Further, body weight, skeletal muscle mass, and grip strength were significantly decreased. Histochemical analysis of the soleus muscles revealed a significant decrease in the cross-sectional area of type 2b muscle fibers. Although type 2a fibers also tended to decrease, chronic stress had no impact on type 1 muscle fibers. Chronic stress increased the expression of REDD1, FoxO1, FoxO3, KLF15, Atrogin1, and FKBP5, but did not affect the expression of myostatin or myogenin. In contrast, chronic stress resulted in a decrease in p-S6 and p-4E-BP1 levels in the soleus muscle. Taken together, these results indicate that chronic stress promotes muscle atrophy by inhibiting mammalian targets of rapamycin complex 1 activity due to the upregulation of its inhibitor, REDD1.
Natural Killer Cell Derived Microvesicles Affect the Function of Trophoblast Cells
Authors: Sokolov Dmitry , Gorshkova Alina , Markova Kseniia , Milyutina Yulia , Pyatygina Kseniya , Zementova Maria , Korenevsky Andrey , Mikhailova Valentina , Selkov Sergey
Published: February 2023

The interaction of natural killer (NK) and trophoblast cells underlies the formation of immune tolerance in the mother–fetus system and the maintenance of the physiological course of pregnancy. In addition, NK cells affect the function of trophoblast cells, interacting with them via the receptor apparatus and through the production of cytokines. Microvesicles (MVs) derived from NK cells are able to change the function of target cells. However, in the overall pattern of interactions between NK cells and trophoblasts, the possibility that both can transmit signals to each other via MVs has not been taken into account. Therefore, the aim of this study was to assess the effect of NK cell-derived MVs on the phenotype, proliferation, and migration of trophoblast cells and their expression of intracellular messengers. We carried out assays for the detection of content transferred from MV to trophoblasts. We found that NK cell-derived MVs did not affect the expression of CD54, CD105, CD126, CD130, CD181, CD119, and CD120a receptors in trophoblast cells or lead to the appearance of CD45 and CD56 receptors in the trophoblast membrane. Further, the MVs reduced the proliferation but increased the migration of trophoblasts with no changes to their viability. Incubation of trophoblast cells in the presence of MVs resulted in the activation of STAT3 via pSTAT3(Ser727) but not via pSTAT3(Tyr705). The treatment of trophoblasts with MVs did not result in the phosphorylation of STAT1 and ERK1/2. The obtained data indicate that NK cell-derived MVs influence the function of trophoblast cells, which is accompanied by the activation of STAT3 signaling.
Pore-Scale Modeling of Microporous Layer for Proton Exchange Membrane Fuel Cell: Effective Transport Properties
Authors: Zhang Heng , Shao Xuanyu , Zhan Zhigang , Sarker Mrittunjoy , Sui Pang-Chieh , Chuang Po-Ya Abel , Pan Mu
Published: February 2023

A microporous layer (MPL) is a transition layer with a porous material structure, located between the gas diffusion layer (GDL) and catalyst layer (CL) in a proton exchange membrane fuel cell (PEMFC). It not only significantly improves electron transfer and heat conduction in membrane electrode assembly, but also effectively manages liquid water transport to enhance the fuel cell performance. The MPL is usually coated on one side of the GDL. The fragile nature of MPL makes it challenging to characterize the effective transport properties using experimental methods. In this study, a stochastic numerical method is implemented to reconstruct the three-dimensional microstructure of an MPL consisting of carbon particles and PTFE. The reliability of the MPL reconstructed model is validated using experimental data. The relationship between the effective transport properties and the compression strain is obtained using the Pore Scale Model (PSM), while the relationship between the liquid water saturation and capillary pressure is solved by Lattice Boltzmann Method (LBM). The effective transport properties in the MPL are then imported into the two-phase flow fuel cell model. It is found that the effective transport parameters in MPL obtained by PSM and LBM can improve the accuracy of the model calculation. This study provides an effective method to reconstruct the microstructure of MPL that can generate precise MPL transport parameters for utilization in various PEMFC performance prediction models.
Features of Self-Diffusion of Tridecane Molecules in a Porous Medium of Kaolinite Used as a Model of a Chemically Inert Membrane
Authors: Maklakov Aleksander , Dvoyashkin Nariman , Khozina Elena
Published: February 2023

The present work focused on the experimental study of the specific features of self-diffusion of tridecane molecules in macroporous kaolinite, which is used as a raw material for the production of chemically inert membranes. The measurements of self-diffusion coefficients by pulsed magnetic field gradient nuclear magnetic resonance (PMFG NMR) revealed an increased translational mobility of tridecane molecules in kaolinite with incomplete filling of the pore space. This effect was accompanied by a sharp change in the slope of the Arrhenius plot of the self-diffusion coefficients of tridecane molecules in kaolinite. An analysis of the diffusion spin echo decay in the tridecane–kaolinite system revealed a discrepancy between the experimental data and the theoretical predictions, considering the effect of the geometry of porous space on molecular mobility. It was shown that the experimental results could be interpreted in terms of a model of two phases of tridecane molecules in the pores of kaolinite, in the gaseous and adsorbed state, coexisting under the fast-exchange conditions. Within the framework of the model, the activation energies of self-diffusion were calculated, which agreed satisfactorily with the experimental data. Additionally, the effects of the internal magnetic field gradients arising in a porous medium loaded with a gas or liquid on the data of the PFG NMR measurements were calculated. It was shown that the effect of magnetic field inhomogeneities on the measured self-diffusion coefficients of tridecane in kaolinite is small and could be neglected.
Effect of Cr on the Microstructure and Mechanical Properties of the Al-Cu-Y-Zr Alloy
Authors: Amer Sayed M. , Glavatskikh Maria V. , Barkov Ruslan Yu. , Loginova Irina S. , Pozdniakov Andrey V.
Published: February 2023

The present investigation aimed at the determination of Cr addition on microstructure, phase composition, and mechanical properties of the Al-Cu-Y-Zr alloy. Quasi-binary alloys of the ternary Al-Cu-Y system with atomic rotation of Cu/Y = 4/1 have a narrow solidification range with high solidus temperature. The addition of 0.3% Cr in the Al-5.1Cu-1.7Y-0.3Zr alloy provides a formation of a novel quaternary Al81–85Cu7–10Y3–4Cr5 phase. L12-Al3(Zr,Y) phase spherical particles with a diameter of 50 nm were nucleated during solution treatment at 600 °C. Al7Cr precipitates were not found in the microstructure. The main strengthening effect of 32.4 MPa and 29.1 MPa was achieved from L12 and θ’(Al2Cu) precipitates, respectively, in accordance with the calculation. The calculated hardness of 61.5HV based on the calculated σy is consistent with the experimental value of hardness. Al3Zr and Al7Cr phases should be in equilibrium with (Al) in accordance with the calculated polythermal section. However, transmission electron microscopy investigation demonstrates the Al3(Zr,Y) precipitates only. As a result, the dissolved Cr atom provides a slightly higher hardness in the rolled and annealed AlCuYZrCr alloy. A suitable combination of strength and ductility was observed both after rolling and after rolling with subsequent annealing at 150 °C for 3 h—the alloy exhibited a yield strength of 308–315 MPa, an ultimate tensile strength of 323–335 MPa, and an elongation to failure of 2.0–3.3%.
Gut Microbiota and Coronary Artery Disease: Current Therapeutic Perspectives
Authors: Katsimichas Themistoklis , Theofilis Panagiotis , Tsioufis Konstantinos , Tousoulis Dimitris
Published: February 2023

The human gut microbiota is the community of microorganisms living in the human gut. This microbial ecosystem contains bacteria beneficial to their host and plays important roles in human physiology, participating in energy harvest from indigestible fiber, vitamin synthesis, and regulation of the immune system, among others. Accumulating evidence suggests a possible link between compositional and metabolic aberrations of the gut microbiota and coronary artery disease in humans. Manipulating the gut microbiota through targeted interventions is an emerging field of science, aiming at reducing the risk of disease. Among the interventions with the most promising results are probiotics, prebiotics, synbiotics, and trimethylamine N-oxide (TMAO) inhibitors. Contemporary studies of probiotics have shown an improvement of inflammation and endothelial cell function, paired with attenuated extracellular matrix remodeling and TMAO production. Lactobacilli, Bifidobacteria, and Bacteroides are some of the most well studied probiotics in experimental and clinical settings. Prebiotics may also decrease inflammation and lead to reductions in blood pressure, body weight, and hyperlipidemia. Synbiotics have been associated with an improvement in glucose homeostasis and lipid abnormalities. On the contrary, no evidence yet exists on the possible benefits of postbiotic use, while the use of antibiotics is not warranted, due to potentially deleterious effects. TMAO inhibitors such as 3,3-dimethyl-1-butanol, iodomethylcholine, and fluoromethylcholine, despite still being investigated experimentally, appear to possess anti-inflammatory, antioxidant, and anti-fibrotic properties. Finally, fecal transplantation carries conflicting evidence, mandating the need for further research. In the present review we summarize the links between the gut microbiota and coronary artery disease and elaborate on the varied therapeutic measures that are being explored in this context.
Cytotoxic Isopentenyl Phloroglucinol Compounds from Garcinia xanthochymus Using LC-MS-Based Metabolomics
Authors: Quan Fan , Luan Xinbo , Zhang Jian , Gao Wenjie , Yan Jian , Li Ping
Published: February 2023

Many unique chemical metabolites with significant antitumor activities have been isolated from Garcinia species and have become a leading hotspot of antitumor research in recent years. The aim of this study was to identify bioactive compounds from different plant parts (leaf, branch, stem bark, fruit, and seed) of G. xanthochymus through combining LC-MS-based metabolomics with cytotoxicity assays. As a result, 70% methanol seed extract exerted significant cytotoxic effects on five human cancer cell types (HL-60, A549, SMMC-7721, MDA-MB-231, and SW480). LC-MS-based metabolomics analysis was used, including principal component analysis (PCA) and orthogonal partial least squares discriminant analysis (OPLS-DA), in order to identify 12 potential markers from seed extract that may relate to bioactivity. LC-MS guidance isolated the markers to obtain three compounds and identified new isopentenyl phloroglucinols (1–3, named garxanthochin A–C), using spectroscopic methods. Among them, garxanthochin B (2) demonstrated moderate inhibitory activities against five human cancer cell types, with IC50 values of 14.71~24.43 μM. These findings indicate that G. xanthochymus seed has significant cytotoxic activity against cancer cells and garxanthochin B has potential applications in the development of antitumor-led natural compounds.
Impacts of Different Prenatal Supplementation Strategies on the Plasma Metabolome of Bulls in the Rearing and Finishing Phase
Authors: Polizel Guilherme Henrique Gebim , Fernandes Arícia Christofaro , Furlan Édison , Prati Barbara Carolina Teixeira , Ferraz José Bento Sterman , Santana Miguel Henrique de Almeida
Published: February 2023

This study investigated the effects of maternal nutrition on the plasma metabolome of Nellore bulls in the rearing and finishing phases, and metabolic differences between these phases. For this study, three nutritional approaches were used in 126 cows during pregnancy: NP—(control) mineral supplementation; PP—protein-energy supplementation in the final third; and FP—protein-energy supplementation during the entire pregnancy. We collected blood samples from male offspring in the rearing (450 ± 28 days old) and finishing phases (660 ± 28 days old). The blood was processed, and from plasma samples, we performed the targeted metabolome analysis (AbsoluteIDQ® p180 Kit). Multiple linear regression, principal component analysis (PCA), repeated measures analysis over time, and an enrichment analysis were performed. PCA showed an overlap of treatments and time clusters in the analyses. We identified significant metabolites among the treatments (rearing phase = six metabolites; finishing phase = three metabolites) and over time (21 metabolites). No significant metabolic pathways were found in the finishing phase, however, we found significant pathways in the rearing phase (Arginine biosynthesis and Histidine metabolism). Thus, prenatal nutrition impacted on plasma metabolome of bulls during the rearing and finishing phase and the different production stages showed an effect on the metabolic levels of bulls.