bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Resolution Limit for Nanoindentation Mapping on Metallic Glasses
Authors: Liang Tao , Yu Qing , Yin Ziliang , Chen Songyi , Liu Ye , Yang Yanping , Lou Hongbo , Shen Baolong , Zeng Zhidan , Zeng Qiaoshi
Published: September 2022

Spatial heterogeneity, as a crucial structural feature, has been intensively studied in metallic glasses (MGs) using various techniques, including two-dimensional nanoindentation mapping. However, the limiting spatial resolution of nanoindentation mapping on MGs remains unexplored. In this study, a comprehensive study on four representative MGs using nanoindentation mapping with a Berkovich indenter was carried out by considering the influence of a normalized indentation spacing d/h (indentation spacing/maximum indentation depth). It appeared to have no significant correlation with the measured hardness and elastic modulus when d/h > 10. The hardness and elastic modulus started to increase slightly (up to ~5%) when d/h < 10 and further started to decrease obviously when d/h < 5. The mechanism behind these phenomena was discussed based on a morphology analysis of residual indents using scanning electron microscopy and atomic force microscopy. It was found that the highest spatial resolution of ~200 nm could be achieved with d/h = 10 using a typical Berkovich indenter for nanoindentation mapping on MGs, which was roughly ten times the curvature radius of the Berkovich indenter tip (not an ideal triangular pyramid) used in this study. These results help to promote the heterogeneity studies of MGs using nanoindentation that are capable of covering a wide range of length scales with reliable and consistent results.
Numerical Investigation of Prefabricated Utility Tunnels Composed of Composite Slabs with Spiral Stirrup-Constrained Connection Based on Damage Mechanics
Authors: Wang Qinghua , Gong Guobin , Hao Jianli , Bao Yuanfeng
Published: September 2022

This paper investigates prefabricated utility tunnels composed of composite slabs with a spiral stirrup-constrained connection, considering material nonlinearity with concrete damage. An experiment was set up based on the prototype of a practical utility tunnel project, and the results were compared with finite element (FEM) simulation results with reasonable agreement obtained. The parametric analysis was carried out considering variations of seam location, haunch height and reinforcement, and embedment depth, using FEM simulations. It is found that, as with the increase in seam distance above haunch, the load capacity increases slightly, while the ductility does not vary much. The haunch height is not found to have an apparent effect on stiffness, load capacity or ductility. The increase in the embedment depth can enhance both the yield and peak loads while decreasing the ductility. A simplified method is proposed for evaluating the seismic performance in terms of deformation coefficient considering ductility demand, based on three different methods for calculating interaction coefficients considering soil–structure interactions. The findings from this investigation provide theoretical and practical guidance for underground engineering design of prefabricated utility tunnels.
Method of Determining Sequence Actions of Products Improvement
Authors: Pacana Andrzej , Siwiec Dominika
Published: September 2022

Material production processes are special processes. As part of continuous improvement, it is extremely important to find the causes of the incompatibilities that occur in them. To increase the effectiveness of these actions, different methods are used. The purpose of this study was to present an original method that allows the classification to improve the combinations of actions of product with material incompatibility. The originality of this method allows for the sequential and coherent operation of adequate analysis techniques of causes resulting in incompatibilities in the product material and, consequently, identifying the reasons that influence their quality. The presented method was developed using a new combination of brainstorming (BM), the Ishikawa diagram with 5M rule, the DEMATEL method, and the algorithm used in the MATLAB software. As a result of the proposed applied method, it is possible to create a sequence of actions that include interactions between important causes of product incompatibility, which was supported by the test of this method. This method was shown to support the creation of a rank of importance of improvement actions. This ranking allows for improvement of any product according to the possibilities of enterprises and simultaneously allows for reducing or eliminating products’ incompatibilities.
Remarkable Enhanced Mechanical Properties of TiAlCrNbV Medium-Entropy Alloy with Zr Additions
Authors: Chen Po-Sung , Shiu Sheng-Jia , Tsai Pei-Hua , Liao Yu-Chin , Jang Jason Shian-Ching , Wu Hsin-Jay , Chang Shou-Yi , Chen Chih-Yen , Tsao I-Yu
Published: September 2022

Most medium entropy alloys (MEAs) exhibit excellent mechanical properties, but their applications are limited because of their high density. This study explores a series of lightweight nonequiatomic Ti65(AlCrNbV)35-xZrx (x = 3, 5, 7, and 10) MEAs with a low density, high strength, and high ductility. To achieve solid solution strengthening, Zr with a large atomic radius was used. In addition, various thermomechanical treatment parameters were adopted to further improve the MEAs’ mechanical properties. The density of the MEAs was revealed to be approximately 5 g/cm3, indicating that they were lightweight. Through an X-ray diffraction analysis, the MEAs were revealed to have a single body-centered cubic structure not only in the as-cast state but also after thermomechanical treatment. In terms of mechanical properties, all the as-cast MEAs with Zr additions achieved excellent performance (>1000 MPa tensile yield strength and 20% tensile ductility). In addition, hot rolling effectively eliminated the defects of the MEAs; under a given yield strength, hot-rolled MEAs exhibited superior ductility relative to non-hot-rolled MEAs. Overall, the Ti65(AlCrNbV)28Zr7 MEAs exhibited an optimum combination of mechanical properties (yield strength > 1200 MPa, plastic strain > 15%) after undergoing hot rolling 50%, cold rolling 70%, and rapid annealing for 30 to 50 s (at a temperature of approximately 850 °C) with a heating rate of 15 K/s. With their extremely high specific yield strength (264 MPa·g/cm3) and high ductility (22%), the Ti65(AlCrNbV)28Zr7 MEAs demonstrate considerable potential for energy and transportation applications.
Design and Characterization of Zeolite/Serpentine Nanocomposite Photocatalyst for Solar Hydrogen Generation
Authors: Altowyan Abeer S. , Shaban Mohamed , Faidey Zeinab M. , Abdelkarem Khaled , Al-Dossari Mawaheb , Abd El-Gawaad N. S. , Kordy Mohamed G. M.
Published: September 2022

In this work, a low-cost, high-yield hydrothermal treatment was used to produce nanozeolite (Zeo), nanoserpentine (Serp), and Zeo/Serp nanocomposites with weight ratios of 1:1 and 2:1. At 250 °C for six hours, the hydrothermal treatment was conducted. Various methods are used to explore the morphologies, structures, compositions, and optical characteristics of the generated nanostructures. The morphological study revealed structures made of nanofibers, nanorods, and hybrid nanofibril/nanorods. The structural study showed clinoptilolite monoclinic zeolite and antigorite monoclinic serpentine with traces of talcum mineral and carbonates. As a novel photoelectrochemical catalyst, the performance of the Zeo/Serp (2:1) composite was evaluated for solar hydrogen generation from water splitting relative to its constituents. At −1 V, the Zeo/Serp (2:1) composite produced a maximum current density of 8.44 mA/g versus 7.01, 6.74, and 6.6 mA/g for hydrothermally treated Zeo/Serp (1:1), Zeo, and Serp, respectively. The Zeo/Serp (2:1) photocatalysts had a solar-to-hydrogen conversion efficiency (STH) of 6.5% and an estimated hydrogen output rate of 14.43 mmole/h.g. Consequently, the current research paved the way for low-cost photoelectrochemical catalytic material for efficient solar hydrogen production by water splitting.
Using Multivariate Quality Statistic for Maintenance Decision Support in a Bearing Ring Grinder
Authors: Ahmer Muhammad , Sandin Fredrik , Marklund Pär , Gustafsson Martin , Berglund Kim
Published: September 2022

Grinding processes’ stochastic nature poses a challenge in predicting the quality of the resulting surfaces. Post-production measurements for form, surface roughness, and circumferential waviness are commonly performed due to infeasibility in measuring all quality parameters during the grinding operation. Therefore, it is challenging to diagnose the root cause of quality deviations in real-time resulting from variations in the machine’s operating condition. This paper introduces a novel approach to predict the overall quality of the individual parts. The grinder is equipped with sensors to implement condition-based maintenance and is induced with five frequently occurring failure conditions for the experimental test runs. The crucial quality parameters are measured for the produced parts. Fuzzy c-means (FCM) and Hotelling’s T-squared (T2) have been evaluated to generate quality labels from the multi-variate quality data. Benchmarked random forest regression models are trained using fault diagnosis feature set and quality labels. Quality labels from the T2 statistic of quality parameters are preferred over FCM approach for their repeatability. The model, trained from T2 labels achieves more than 94% accuracy when compared to the measured ring disposition. The predicted overall quality using the sensors’ feature set is compared against the threshold to reach a trustworthy maintenance decision.
A Vehicle Comparison and Re-Identification System Based on Residual Network
Authors: Yin Weifeng , Min Yusong , Zhai Junyong
Published: September 2022

In the highway intelligent monitoring system, it is difficult to find the target vehicle through millions of pictures because of the presence of fake-licensed vehicles. In order to solve this problem, a vehicle comparison and re-identification (Re-ID) system is built in this paper. By introducing Circle loss and Generalized-Mean(GeM) pooling, vehicle feature extraction and storage, vehicle comparison and vehicle search can be realized. Experimental results show that the proposed algorithm reaches 95.79% of the mean Average Precision (mAP) on the vehicle search task, which meets the requirements of practical applications.
An Alpha/Beta Radiation Mapping Method Using Simultaneous Localization and Mapping for Nuclear Power Plants
Authors: Liu Xin , Cheng Lan , Yang Yapeng , Yan Gaowei , Xu Xinying , Zhang Zhe
Published: September 2022

Nuclear safety has always been a focal point in the field of nuclear applications. Mobile robots carrying specific sensors for nuclear-radiation detection have become an alternative to manual detection. This work presents an autonomous α/β radiation mapping framework, using a mobile robot carrying a light detection and ranging (LiDAR) and a nuclear-radiation-detection sensor. The method employs simultaneous localization and mapping (SLAM) techniques and radiation-detection sensors. Cartographer is adopted as a demonstration example to map the unknown environment. Radiation data are obtained through the radiation detection sensor and projected onto the environment map after coordinate alignment. The color-coded radiation map is shown on the environment map according to the dose rate. The simulation and real-environment experiments in a robot-operating system (ROS) validate the effectiveness of the proposed method in different radiation scenarios for both indoor and outdoor environments.
Research on Adaptive Control of Grinding Force for Carbide Indexable Inserts Grinding Process Based on Spindle Motor Power
Authors: Chen Peng , Zhang Xianglei , Feng Ming , Li Sisi , Pan Xiaoming , Feng Wei
Published: September 2022

The grinding force is the most sensitive physical measure of reaction loads in the grinding process. To enhance surface quality and assure high efficiency and stability of the grinding process, it is essential to accomplish adaptive control of the grinding force. This paper suggests a grinding force adaptive control system based on spindle motor power feedback, considering the process–machine interaction. The spindle motor power is utilized as a proxy for the grinding force because of the mapping relationship between the two variables. The machine tool’s feed rate is automatically modified to achieve adaptive control of the grinding force, after assessing the discrepancy between the collected spindle motor power and the preset power. Finally, a cemented carbide tool grinding experiment was performed on a 2MZK7150 CNC tool grinder. During the experiment, the grinding force was precisely controlled between 80 and 100 N, ensuring machining quality and increasing machining efficiency. The experimental results show that the adaptive control system can meet the high-efficiency and high-quality machining requirements of cemented carbide rotary blades.
Quality-Enhancing Techniques for Model-Based Reconstruction in Magnetic Particle Imaging
Authors: Gapyak Vladyslav , März Thomas , Weinmann Andreas
Published: September 2022

Magnetic Particle Imaging is an imaging modality that exploits the non-linear magnetization response of superparamagnetic nanoparticles to a dynamic magnetic field. In the multivariate case, measurement-based reconstruction approaches are common and involve a system matrix whose acquisition is time consuming and needs to be repeated whenever the scanning setup changes. Our approach relies on reconstruction formulae derived from a mathematical model of the MPI signal encoding. A particular feature of the reconstruction formulae and the corresponding algorithms is that these are independent of the particular scanning trajectories. In this paper, we present basic ways of leveraging this independence property to enhance the quality of the reconstruction by merging data from different scans. In particular, we show how to combine scans of the same specimen under different rotation angles. We demonstrate the potential of the proposed techniques with numerical experiments.
Anomaly Detection Algorithm Based on Broad Learning System and Support Vector Domain Description
Authors: Huang Qun , Zheng Zehua , Zhu Wenhao , Fang Xiaozhao , Fang Ribo , Sun Weijun
Published: September 2022

Deep neural network-based autoencoders can effectively extract high-level abstract features with outstanding generalization performance but suffer from sparsity of extracted features, insufficient robustness, greedy training of each layer, and a lack of global optimization. In this study, the broad learning system (BLS) is improved to obtain a new model for data reconstruction. Support Vector Domain Description (SVDD) is one of the best-known one-class-classification methods used to solve problems where the proportion of sample categories of data is extremely unbalanced. The SVDD is sensitive to penalty parameters C, which represents the trade-off between sphere volume and the number of target data outside the sphere. The training process only considers normal samples, which leads to a low recall rate and weak generalization performance. To address these issues, we propose a BLS-based weighted SVDD algorithm (BLSW_SVDD), which introduces reconstruction error weights and a small number of anomalous samples when training the SVDD model, thus improving the robustness of the model. To evaluate the performance of BLSW_SVDD model, comparison experiments were conducted on the UCI dataset, and the experimental results showed that in terms of accuracy and F1 values, the algorithm has better performance advantages than the traditional and improved SVDD algorithms.
Electrophysiological Brain Response to Error in Solving Mathematical Tasks
Authors: Alvarado-Rodríguez Francisco J. , Ibarra-González Karla P. , Eccius-Wellmann Cristina , Vélez-Pérez Hugo , Romo-Vázquez Rebeca
Published: September 2022

Objective: to identify energy patterns in the electrophysiological bands of the brain as possible indicators of overconfidence in students when they receive feedback indicating they have erred while solving a mathematical task. Methodology: EEG were recorded from 20 subjects while they performed mathematical exercises. Energy changes in the delta and theta bands before, during, and after solving the task were analyzed. Results: when the answers to the exercises were shown, an increase of energy in the delta band was observed in participants with correct answers but a reduction in that band in those who answered incorrectly. Subjects with incorrect answers received feedback and then attempted to solve a second, similar, exercise. Subjects who answered correctly showed an increase of energy theta, while those with incorrect answers showed a decrease. Conclusions: the energy changes when subjects erred while solving a mathematical task could serve as a quantitative indicator for characterizing overconfidence.
Research on Simulation and Decision-Making of Coal Mine Workers’ Behavior Risk
Authors: Yu Kai , Zhang Sai , Liu Pingping , Zhou Lujie , Chen Jing
Published: September 2022

The behavior risk of workers is one of the main restricting factors in coal mine safety decision-making and management. In this paper, the behavior and decision-making process of individuals and organizations are modeled and analyzed to solve this challenge, based on data analysis and behavior decision-making. Based on system dynamics (SD), this paper proposes an unsafe behavior correction system (SD-Ipt) for coal miners to reduce occupational risk. The “1 + 1 + 3 + X” behavior risk correction decision-making system is constructed, and the implementation scheme of the system is put forward, which has been applied in coal mines. This study can effectively correct the unsafe behavior of coal mining enterprises and improve the occupational safety and health management ability of coal mining enterprises.
Efficient Numerical Solutions to a SIR Epidemic Model
Authors: Mehdizadeh Khalsaraei Mohammad , Shokri Ali , Ramos Higinio , Yao Shao-Wen , Molayi Maryam
Published: September 2022

Two non-standard predictor-corrector type finite difference methods for a SIR epidemic model are proposed. The methods have useful and significant features, such as positivity, basic stability, boundedness and preservation of the conservation laws. The proposed schemes are compared with classical fourth order Runge–Kutta and non-standard difference methods (NSFD). The stability analysis is studied and numerical simulations are provided.
Dynamics of the Vibro-Impact Nonlinear Damped and Forced Oscillator under the Influence of the Electromagnetic Actuation
Authors: Herisanu Nicolae , Marinca Bogdan , Marinca Vasile
Published: September 2022

The main objective of the present work is to find an approximate analytical solution for the nonlinear differential equation of the vibro-impact oscillator under the influence of the electromagnetic actuation near the primary resonance. The trigger of vibro-impact regime is due to Hertzian contact. The optimal auxiliary functions method (OAFM) is utilized to give an analytical approximate solution of the problem. The influences of static normal load and electromagnetic actuation near the primary resonance are completely studied. The main novelties of the proposed procedure are the presence of some new adequate auxiliary functions, the introduction of the convergence-control parameters, the original construction of the initial and of the first iteration, and the freedom to choose the method for determining the optimal values of the convergence-control parameters. All these led to an explicit and accurate analytical solution, which is another novelty proposed in the paper. This technique is very accurate, simple, effective, and easy to apply using only the first iteration. A second objective was to perform an analysis of stability of the model using the multiple scales method and the eigenvalues of the Jacobian matrix.
Disassortative Mixing and Systemic Rational Behaviour: How System Rationality Is Influenced by Topology and Placement in Networked Systems
Authors: Kasthurirathna Dharshana , Ratnayake Prasan , Piraveenan Mahendra
Published: September 2022

Interdependent decisionmaking of individuals in social systems can be modelled by games played on complex networks. Players in such systems have bounded rationality, which influences the computation of equilibrium solutions. It has been shown that the ‘system rationality’, which indicates the overall rationality of a network of players, may play a key role in the emergence of scale-free or core-periphery topologies in real-world networks. In this work, we identify optimal topologies and mixing patterns of players which can maximise system rationality. Based on simulation results, we show that irrespective of the placement of nodes with higher rationality, it is the disassortative mixing of node rationality that helps to maximize system rationality in a population. In other words, the findings of this work indicate that the overall rationality of a population may improve when more players with non-similar individual rationality levels interact with each other. We identify particular topologies such as the core-periphery topology, which facilitates the optimisation of system rationality. The findings presented in this work may have useful interpretations and applications in socio-economic systems for maximizing the utility of interactions in a population of strategic players.
Revision of a Failed Primary Total Hip Arthroplasty following Excessive Reaming with a Medial Cup Protrusion
Authors: Ivanova Silviya , Vuillemin Nicolas , Hapa Onur , Siebenrock Klaus A. , Keel Marius J. B. , Tosounidis Theodoros H. , Bastian Johannes D.
Published: September 2022

Background and Objectives: Atraumatic intrapelvic protrusion of the acetabular component following excessive reaming of the acetabulum with a far medial positioning of the cup is a rare, but serious complication of a total hip arthroplasty (THA). This study analyzes the factors contributing to this uncommon complication and presents the outcome after the revision surgery using the Ganz reinforcement ring combined with a bone graft and plating of the posterior column and/or screws for the anterior column. Materials and Methods: A retrospective case series study with seven patients (four males, mean age 76 ± 10 years (60–86)) that underwent a revision THA within 24 ± 17 days (5–60) after an atraumatic periprosthetic acetabular fracture with a medial cup protrusion was performed. All fractures were reconstructed with a Ganz reinforcement ring and bone graft with a mean follow-up of 1.7 ± 1.7 years (0.5–5). Radiographs were evaluated for the following: (i) cup positioning immediately after the primary THA and the revision surgery, (ii) cup migration in the follow-up, and (iii) fracture healing. Results: The position of the acetabular component as assessed on the postoperative radiographs after the index surgery and before the complete medial cup protrusion showed a cup placement beyond the ilioischial line indicative of a fracture of the medial wall. The revision surgery with the reconstruction of the medial wall with a Ganz reinforcement ring combined with a bone graft restored in the presented cases the center of rotation in the horizontal direction with a statistical significance (p < 0.05). During the follow-up, there was no aseptic loosening with the relevant cup migration or significant change in the position of the acetabular cup at the final follow-up (p > 0.05) after the revision. All seven fractures and bone grafts realized a bone union until the latest follow-up. Conclusions: Following excessive reaming, the acetabular component was placed too far medially and resulted in an intrapelvic cup protrusion. An unstable cup following a fracture of the medial wall was evident on the immediate postoperative radiographs. In the case of the medial wall perforation with an intrapelvic cup protrusion after the primary THA, the reconstruction with a Ganz reinforcement ring was a successful treatment option resulting in the fracture healing and a stable cup positioning. Surgeons should be aware of that rare and probably underreported complication and restore the anatomic center of rotation by treating the defect intraoperatively.
Conservative Management of Atypical Endometrial Hyperplasia and Early Endometrial Cancer in Childbearing Age Women
Authors: Uccella Stefano , Zorzato Pier , Dababou Susan , Bosco Mariachiara , Torella Marco , Braga Andrea , Frigerio Matteo , Gardella Barbara , Cianci Stefano , Laganà Antonio , Franchi Massimo , Garzon Simone
Published: September 2022

Total hysterectomy and bilateral adnexectomy is the standard treatment for atypical endometrial hyperplasia and early-stage endometrial cancer. However, the recommended surgical treatment precludes future pregnancy when these conditions are diagnosed in women in their fertile age. In these patients, fertility-sparing treatment may be feasible if the desire for childbearing is consistent and specific conditions are present. This review summarizes the available evidence on fertility-sparing management for atypical endometrial hyperplasia and early-stage endometrial cancer. Historically, oral progestins have been the mainstay of conservative management for atypical endometrial hyperplasia and stage IA endometrioid endometrial cancer with no myometrial invasion, although there is no consensus on dosage and treatment length. Intrauterine progestin therapy has proved a valid alternative option when oral progestins are not tolerated. GnRH analogs, metformin, and hysteroscopic resection in combination with progestins appear to increase the overall efficacy of the treatment. After a complete response, conception is recommended; alternatively, maintenance therapy with strict follow-up has been proposed to decrease recurrence. The risk of disease progression is not negligible, and clinicians should not overlook the risk of hereditary forms of the disease in young patients, in particular, Lynch syndrome. Hysterectomy is performed once the desire for childbearing desire has been established. The conservative management of atypical endometrial hyperplasia and early-stage endometrial cancer is feasible, provided a strong desire for childbearing and permitting clinical–pathological conditions. However, patients must be aware of the need for a strict follow-up and the risk of progression with a possible consequent worsening of the prognosis. More homogenous and well-designed studies are necessary to standardize and identify the best treatment and follow-up protocols.
Antibiotic Abuse and Antimicrobial Resistance in Hospital Environment: A Retrospective Observational Comparative Study
Authors: Nardulli Patrizia , Hall Gabriel Gustafsson , Quarta Alessandro , Fruscio Giovanni , Laforgia Mariarita , Garrisi Vito M. , Ruggiero Roberta , Scacco Salvatore , De Vito Danila
Published: September 2022

Background and Objectives: Antimicrobial resistance represents a serious problem, and it may be life-threatening in the case of severe hospital-acquired infections (HAI). Antibiotic abuse and multidrug resistance (MDR) have significantly increased this burden in the last decades. The aim of this study was to investigate the distribution and susceptibility rates of five selected bacterial species (E. coli, K. pneumoniae, P. aeruginosa, S. aureus and E. faecium) in two healthcare settings located in the Apulia region (Italy). Materials and Methods: Setting n.1 was a university hospital and setting n.2 was a research institute working on oncological patients. All the enrolled patients were diagnosed for bacterial HAI. The observation period was between August and September 2021. Clinical samples were obtained from several biological sources, in different hospital wards. Bacterial identification and susceptibility were tested by using the software VITEC 2 Single system. Results: In this study, a higher incidence of multi-drug-resistant K. pneumoniae was reported (42,2% in setting n.1 and 50% in setting n.2), with respect to the Italian 2019 statistics report (30.3%). All the isolates of E. faecium and S. aureus were susceptible to linezolid. All the bacterial isolates of P. aeruginosa and most of K. pneumoniae were susceptible to ceftazidime–avibactam. Amikacin and nitrofurantoin represented a good option for treating E. coli infections. Multidrug-resistant (MDR) P. aeruginosa, methicillin-resistant S. aureus (MRSA) and vancomycin-resistantE. faecium (VRE) had a lower incidence in the clinical setting, with respect to E. coli and K. pneumoniae. Conclusions: The data obtained in this study can support clinicians towards a rational and safe use of antibiotics for treating the infections caused by these resistant strains, to enhance the overall efficacy of the current antibiotic protocols used in the main healthcare environments.
Empathy among Saudi Residents at a Tertiary Academic Center during the COVID-19 Pandemic and Its Association with Perceived Stress
Authors: AlSaif Haytham I. , Alenezi Mamdouh N. , Asiri Mohammed , Alshaibani Khalid O. , Alrasheed Abdullah A. , Alsaad Saad M. , Batais Mohammed A.
Published: September 2022

Background and Objectives: Empathy is an important attribute of a healthy doctor–patient relationship. Although multiple studies have assessed empathy in different countries, little is known about its levels among Saudi residents and its association with perceived stress. Objectives: To assess the levels of empathy and to identify if there is an association with stress in general and across the demographic and training characteristics of residents. Materials and Methods: A cross-sectional questionnaire-based study was carried out from December 2020 to March 2021 among residents training at a tertiary academic center in Riyadh, Saudi Arabia. Empathy and perceived stress were measured using the Jefferson Scale of Empathy (JSE) and the Perceived Stress Scale (PSS). Results: A total of 229 residents participated. The mean JSE score was 105.25 ± 15.35. The mean JSE scores were significantly higher among residents training in pediatrics (mean difference (MD) = 17.35, p < 0.001), family medicine (MD = 12.24, p = 0.007), and medical specialties (MD = 11.11, p = 0.012) when compared with surgical specialties and anesthesia. In addition, residents who worked 1–4 on-calls per month had a higher mean JSE score (MD = 11.23, p = 0.028) compared with those who worked 7 or more on-calls. Lastly, no correlation between empathy and perceived stress was detected in the whole sample (r = −0.007, p = 0.913); however, there was a correlation among residents training in medical specialties (r = −0.245, p = 0.025). Conclusion: Residents in our study had empathy levels comparable with Asian but lower than Western residents. We recommend qualitative studies that explore potential factors that might affect empathy among residents and studying the association between empathy and perceived stress among medical residents. Postgraduate curricula should incorporate interventions that foster a more empathetic doctor–patient relationship.
Cytochrome 4Z1 Expression Connotes Unfavorable Prognosis in Ovarian Cancers
Authors: Al-saraireh Yousef M. , Alshammari Fatemah O. F. O. , Satari Anas O. , Al-mahdy Yanal S. , Almuhaisen Ghadeer H. , Abu-azzam Omar H. , Uwais Ala N. , Abufraijeh Seham M. , Al-Kharabsheh Ahlam M. , Al-dalain Sa’ed M. , Al-Qtaitat Aiman , Al-Tarawneh Fatima , Al Shuneigat Jehad M. , Al-Sarayreh Sameeh A.
Published: September 2022

Background and Objective: Ovarian cancer is a leading cause of death in females. Since its treatment is challenging and causes severe side effects, novel therapies are urgently needed. One of the potential enzymes implicated in the progression of cancers is Cytochrome 4Z1 (CYP4Z1). Its expression in ovarian cancer remains unknown. Therefore, the current study aims to assess CYP4Z1 expression in different subtypes of ovarian cancers. Materials and Methods: Immunohistochemistry was used to characterize CYP4Z1 expression in 192 cases of ovarian cancers along with eight normal ovarian tissues. The enzyme’s association with various clinicopathological characteristics and survival was determined. Results: CYP4Z1 was strongly expressed in 79% of ovarian cancers, compared to negative expression in normal ovarian samples. Importantly, significantly high CYP4Z1 expres-sion was determined in patients with advanced-stage cancer and a high depth of invasion (p < 0.05). Surprisingly, CYP4Z1 expression was significantly associated with a low patient survival rate. Univariate analysis revealed that patient survival was strongly associated with CYP4Z1 expression, tumor stage, depth of invasion, and lymph node metastasis (p < 0.05). Multivariate analysis showed that only CYP4Z1 expression was significantly associated with patient survival (p < 0.05). Conclusions: CYP4Z1 expression is correlated with shorter patient survival and has been identified as an independent indicator of a poor prognosis for ovarian cancer patients.
Principle and Application of Frequency-Domain Characteristic Analysis of Fractional-Order Memristor
Authors: Yu Bo , Pu Yifei , He Qiuyan , Yuan Xiao
Published: September 2022

Scaling fractional-order memristor circuit is important for realizing a fractional-order memristor. However, the effective operating-frequency range, operation order, and fractional-order memristance of the scaling fractional-order memristor circuit have not been studied thoroughly; that is, the fractional-order memristance in the effective operating-frequency range has not been calculated quantitatively. The fractional-order memristance is a similar and equally important concept as memristance, memcapacitance, and meminductance. In this paper, the frequency-domain characteristic-analysis principle of the fractional-order memristor is proposed based on the order- and F-frequency characteristic functions. The reasons for selecting the order- and F-frequency characteristic functions are explained. Subsequently, the correctness of the frequency-domain characteristic analysis using the order- and F-frequency characteristic functions is verified from multiple perspectives. Finally, the principle of the frequency-domain characteristic analysis is applied to the recently realized chain-scaling fractional-order memristor circuit. The results of this study indicate that the principle of the frequency-domain characteristic analysis of the fractional-order memristor can successfully calculate the fractional-order memristance of the chain-scaling fractional-order memristor circuit. The proposed principle of frequency-domain characteristic analysis can also be applied to mem-elements, such as memristors, memcapacitors, and meminductors. The main contribution of this study is the principle of the frequency-domain characteristic analysis of the fractional-order memristor based on the order- and F-frequency characteristic functions.
Genomic Adaptations of Saccharomyces Genus to Wine Niche
Authors: García-Ríos Estéfani , Guillamón José Manuel
Published: September 2022

Wine yeast have been exposed to harsh conditions for millennia, which have led to adaptive evolutionary strategies. Thus, wine yeasts from Saccharomyces genus are considered an interesting and highly valuable model to study human-drive domestication processes. The rise of whole-genome sequencing technologies together with new long reads platforms has provided new understanding about the population structure and the evolution of wine yeasts. Population genomics studies have indicated domestication fingerprints in wine yeast, including nucleotide variations, chromosomal rearrangements, horizontal gene transfer or hybridization, among others. These genetic changes contribute to genetically and phenotypically distinct strains. This review will summarize and discuss recent research on evolutionary trajectories of wine yeasts, highlighting the domestication hallmarks identified in this group of yeast.
Emergence and Transfer of Plasmid-Harbored rmtB in a Clinical Multidrug-Resistant Pseudomonas aeruginosa Strain
Authors: Gao Jiacong , Wei Xiaoya , Yin Liwen , Jin Yongxin , Bai Fang , Cheng Zhihui , Wu Weihui
Published: September 2022

Multidrug-resistant (MDR) Pseudomonas aeruginosa poses a great challenge to clinical treatment. In this study, we characterized a ST768 MDR P. aeruginosa strain, Pa150, that was isolated from a diabetic foot patient. The minimum inhibitory concentration (MIC) assay showed that Pa150 was resistant to almost all kinds of antibiotics, especially aminoglycosides. Whole genome sequencing revealed multiple antibiotic resistant genes on the chromosome and a 437-Kb plasmid (named pTJPa150) that harbors conjugation-related genes. A conjugation assay verified its self-transmissibility. On the pTJPa150 plasmid, we identified a 16S rRNA methylase gene, rmtB, that is flanked by mobile genetic elements (MGEs). The transfer of the pTJPa150 plasmid or the cloning of the rmtB gene into the reference strain, PAO1, significantly increased the bacterial resistance to aminoglycoside antibiotics. To the best of our knowledge, this is the first report of an rmtB-carrying conjugative plasmid isolated from P. aeruginosa, revealing a novel possible transmission mechanism of the rmtB gene.
Bacterial Compositional Shifts of Gut Microbiomes in Patients with Rheumatoid Arthritis in Association with Disease Activity
Authors: El Menofy Nagwan G. , Ramadan Mohammed , Abdelbary Eman R. , Ibrahim Hatem G. , Azzam Adel I. , Ghit Mohamed M. , Ezz Ahmed S. , Gazar Yasser A. , Salah Mohammed
Published: September 2022

Background: Rheumatoid arthritis (RA) is a chronic inflammatory disabling autoimmune disorder. Little is known regarding the association between the gut microbiome and etiopathogenesis of RA. We aimed to dissect the differences in gut microbiomes associated with RA in comparison to healthy individuals and, in addition, to identify the shifts in the bacterial community in association with disease activity; Methods: In order to identify compositional shifts in gut microbiomes of RA patients, V3-V4 hypervariable regions of 16S rRNA were sequenced using Illumina MiSeq. In total, sixty stool samples were collected from 45 patients with RA besides 15 matched healthy subjects; Results: Notably, RA microbiomes were significantly associated with diverse bacterial communities compared with healthy individuals. Likewise, a direct association between bacterial diversity and disease activity was detected in RA patients (Kruskal Wallis; p = 0.00047). In general, genus-level analysis revealed a positive coexistence between RA and Megasphaera, Adlercreutzia, Ruminococcus, Bacteroides, Collinsella, and Acidaminococcus. Furthermore, Spearman correlation analysis significantly stratified the most dominant genera into distinct clusters that were mainly based on disease activity (r ≥ 0.6; p ≤ 0.05). The predictive metabolic profile of bacterial communities associated with RA could support the potential impact of gut microbiomes in either the development or recovery of RA; Conclusions: The overall shifts in bacterial composition at different disease statuses could confirm the cross-linking of certain genera either to causation or progression of RA.
Mycobacterium tuberculosis whiB3 and Lipid Metabolism Genes Are Regulated by Host Induced Oxidative Stress
Authors: Barrientos Omar M. , Langley Elizabeth , González Yolanda , Cabello Carlos , Torres Martha , Guzmán-Beltrán Silvia
Published: September 2022

The physiological state of the human macrophage may impact the metabolism and the persistence of Mycobacterium tuberculosis. This pathogen senses and counters the levels of O2, CO, reactive oxygen species (ROS), and pH in macrophages. M. tuberculosis responds to oxidative stress through WhiB3. The goal was to determine the effect of NADPH oxidase (NOX) modulation and oxidative agents on the expression of whiB3 and genes involved in lipid metabolism (lip-Y, Icl-1, and tgs-1) in intracellular mycobacteria. Human macrophages were first treated with NOX modulators such as DPI (ROS inhibitor) and PMA (ROS activator), or with oxidative agents (H2O2 and generator system O2•−), and then infected with mycobacteria. We determined ROS production, cell viability, and expression of whiB3, as well as genes involved in lipid metabolism. PMA, H2O2, and O2•− increased ROS production in human macrophages, generating oxidative stress in bacteria and augmented the gene expression of whiB3, lip-Y, Icl-1, and tgs-1. Our results suggest that ROS production in macrophages induces oxidative stress in intracellular bacteria inducing whiB3 expression. This factor may activate the synthesis of reserve lipids produced to survive in the latency state, which allows its persistence for long periods within the host.
Determination of Chemical Compounds and Investigation of Biological Properties of Matricaria chamomilla Essential Oils, Honey, and Their Mixture
Authors: Qasem Ahmed , Assaggaf Hamza , Montesano Domenico , Khalil Zineb , Al-Mijalli Samiah Hamad , Baaboua Aicha EL , El Omari Nasreddine , El Menyiy Naoual , Bakrim Saad , Sheikh Ryan A. , Alshahrani Mohammed Merae , Awadh Ahmed Abdullah Al , Zengin Gokhan , Bouyahya Abdelhakim , Mrabti Hanae Naceiri
Published: September 2022

This exploratory investigation aimed to determine the chemical composition and evaluate some biological properties, such as antioxidant, anti-inflammatory, antidiabetic, and antimicrobial activities, of Matricaria chamomilla L. essential oils (EOs). EOs of M. chamomilla were obtained by hydrodistillation and phytochemical screening was performed by gas chromatography–mass spectrophotometry (GC-MS). The antimicrobial activities were tested against different pathogenic strains of microorganisms by using disc diffusion assay, the minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) methods. The antidiabetic activity was performed in vitro using the enzyme inhibition test. The antioxidant activity of EOs was tested using the free radical scavenging ability (DPPH method), ferrous ion chelating (FIC) ability, and β-carotene bleaching assay. The anti-inflammatory effects were tested in vivo using the carrageenan-induced paw edema method and in vitro using the inhibition of the lipoxygenase test. The analysis of the phytochemical composition by GC-MS revealed that camphor (16.42%) was the major compound of EOs, followed by 3-carene (9.95%), β-myrcene (8.01%), and chamazulene (6.54%). MCEO, honey, and their mixture exhibited antioxidant activity against the DPPH assay (IC50 ranging from 533.89 ± 15.05 µg/mL to 1945.38 ± 12.71 µg/mL). The mixture exhibited the best radical scavenging activity, with an IC50 of 533.89 ± 15.05 µg/mL. As antidiabetic effect, EO presented the best values against α-glucosidase (265.57 ± 0.03 μg/mL) and α-amylase (121.44 ± 0.05 μg/mL). The EOs and honey mixture at a dose of 100 mg/kg exhibited a high anti-inflammatory effect, with 63.75% edema inhibition after 3 h. The impact of EOs on the studied species showed an excellent antimicrobial (Staphylococcus aureus ATCC 29213 (22.97 ± 0.16 mm)), antifungal (Aspergillus niger (18.13 ± 0.18 mm)) and anti-yeast (Candida albicans (21.07 ± 0.24 mm) effect against all the tested strains. The results obtained indicate that the EOs of M. chamomilla could be a potential drug target against diabetes, inflammation and microbial infections; however, further investigations to assess their bioactive molecules individually and in combination are greatly required.
Analysis of Polar Lipids in Hemp (Cannabis sativa L.) By-Products by Ultra-High Performance Liquid Chromatography and High-Resolution Mass Spectrometry
Authors: Banskota Arjun H. , Jones Alysson , Hui Joseph P. M. , Stefanova Roumiana , Burton Ian W.
Published: September 2022

Polar lipids were extracted from residual biomass of hemp (Cannabis sativa L.) by-products with EtOH and partitioned into aqueous and chloroform fractions. The chloroform fractions were studied for their lipid composition using solid-phase extraction (SPE) followed by UHPLC/HRMS and NMR analyses. The 1H NMR and gravimetric yield of SPE indicated triacylglycerols covered ≥ 51.3% of the chloroform fraction of hemp seed hulls and hemp cake. UHPLC/HRMS analyses of remaining polar lipids led to the identification of nine diacylglycerols (DAGs), six lysophosphatidylcholines (LPCs), five lysophosphatidylethanolamines (LPEs), eight phosphatidylethanolamines (PEs), and thirteen phosphatidylcholines (PCs) for the first time from hemp seed hulls. The regiospecificity of fatty acyl substitutes in glycerol backbone of individual phospholipids were assigned by analyzing the diagnostic fragment ions and their intensities. The heat-map analysis suggested that DAG 18:2/18:2, 1-LPC 18:2, 1-LPE 18:2, PE 18:2/18:2, and PC 18:2/18:2 were the predominant molecules within their classes, supported by the fact that linoleic acid was the major fatty acid covering > 41.1% of the total fatty acids determined by GC-FID analysis. The 31P NMR analysis confirmed the identification of phospholipids and suggested PC covers ≥ 37.9% of the total phospholipid present in hemp by-products. HPLC purification led to the isolation of 1,2-dilinoleoylphosphatidylcholine and 1-palmitoyl-2-linoleoylphosphatidylcholine. These two major PCs further confirmed the UHPLC/HRMS finding.
Identification of Gedunin from a Phytochemical Depository as a Novel Multidrug Resistance-Bypassing Tubulin Inhibitor of Cancer Cells
Authors: Khalid Sami A. , Dawood Mona , Boulos Joelle C. , Wasfi Monica , Drif Assia , Bahramimehr Faranak , Shahhamzehei Nasim , Shan Letian , Efferth Thomas
Published: September 2022

The chemotherapy of tumors is frequently limited by the development of resistance and severe side effects. Phytochemicals may offer promising candidates to meet the urgent requirement for new anticancer drugs. We screened 69 phytochemicals, and focused on gedunin to analyze its molecular modes of action. Pearson test-base correlation analyses of the log10IC50 values of 55 tumor cell lines of the National Cancer Institute (NCI), USA, for gedunin with those of 91 standard anticancer agents revealed statistically significant relationships to all 10 tested microtubule inhibitors. Thus, we hypothesized that gedunin may be a novel microtubule inhibitor. Confocal microscopy, cell cycle measurements, and molecular docking in silico substantiated our assumption. Agglomerative cluster analyses and the heat map generation of proteomic data revealed a subset of 40 out of 3171 proteins, the expression of which significantly correlated with sensitivity or resistance for the NCI cell line panel to gedunin. This indicates the complexity of gedunin’s activity against cancer cells, underscoring the value of network pharmacological techniques for the investigation of the molecular modes of drug action. Finally, we correlated the transcriptome-wide mRNA expression of known drug resistance mechanism (ABC transporter, oncogenes, tumor suppressors) log10IC50 values for gedunin. We did not find significant correlations, indicating that gedunin’s anticancer activity might not be hampered by classical drug resistance mechanisms. In conclusion, gedunin is a novel microtubule-inhibiting drug candidate which is not involved in multidrug resistance mechanisms such as other clinically established mitotic spindle poisons.