bluuebunny/crossref_metadata_2025 huggingface dataset:
Spatial Behavior of Solutions in Linear Thermoelasticity with Voids and Three Delay Times
Authors: Carini Manuela , Zampoli Vittorio
Published: October 2023

This brief contribution aims to complement a study of well-posedness started by the same authors in 2020, showing—for that same mathematical model—the existence of a domain of influence of external data. The object of investigation, we recall, is a linear thermoelastic model with a porous matrix modeled on the basis of the Cowin–Nunziato theory, and for which the heat exchange phenomena are intended to obey a time-differential heat transfer law with three delay times. We therefore consider, without reporting it explicitly, the (suitably adapted) initial-boundary value problem formulated at that time, as well as some analytical techniques employed to handle it in order to address the uniqueness and continuous dependence questions. Here, a domain of influence theorem is proven, showing the spatial behavior of the solution in a cylindrical domain, by activating the hypotheses that make the model thermodynamically consistent. The theorem, in detail, demonstrates that for a finite time t>0, the assigned external (thermomechanical) actions generate no disturbance outside a bounded domain contained within the cylindrical region of interest. The length of the work is deliberately kept to a minimum, having opted where possible for bibliographic citations in favor of greater reading fluency.
Resultant Normal Contact Force-Based Contact Friction Model for the Combined Finite-Discrete Element Method and Its Validation
Authors: Liu He , Shao Zuliang , Lin Qibin , Lei Yiming , Du Chenglei , Pan Yucong
Published: October 2023

In the conventional FDEM (Combined Finite and Discrete Element Method), each contact pair might have multiple contact points where friction forces are applied, leading to non-unique friction force assignments and potentially introducing computational errors. This study introduces a new contact friction algorithm for FDEM based on the resultant normal contact force. This method necessitates determining the friction force at a unique equivalent contact point, thereby significantly simplifying the computational flow and reducing memory usage. A series of numerical tests are performed to validate the effectiveness of the proposed contact model. Using collision and block sliding tests, the proposed contact friction model is verified to be able to accurately capture the frictional effect between discrete bodies and circumvent the problematic kinetic energy dissipation issue associated with the original contact friction algorithm. For the Brazilian splitting and uniaxial compression tests, the simulated results closely align with those generated using the original contact friction algorithm and match the experimental measurements well, demonstrating the applicability of the proposed algorithm in fracturing analysis. Furthermore, by using the proposed contact friction algorithm, a computational efficiency enhancement of 8% in contact force evaluation can be achieved.
Study on the Stiffness and Dynamic Characteristics of a Bridge Approach Zone: Tests and Numerical Analyses
Authors: Hu Ping , Liu Wei , Liu Huo , Wu Leixue , Wang Yang , Guo Wei
Published: October 2023

This study focuses on the stiffness and dynamic characteristic rules of a bridge approach zone in a high-speed railway (HSR). Indoor and in situ tests were performed to explore the stiffness and dynamic characteristics of the roadbed filling. Based on the test results, an effective track-subgrade finite element model (FEM) of a high-speed train (HST) was established. The FEM simulated the train load and model boundaries based on the obtained loads and viscoelastic artificial boundaries. Suitable elements were then selected to simulate the various components of the system and the constraint equations were established and solved using multi-point constraints. The model was verified by comparing the time–history curve characteristics, the frequency-domain characteristics and the results obtained from different modeling methods with the measured results. The influence of stiffness on the dynamic characteristics of the bridge approach zone were subsequently analyzed based on the aforementioned tests and simulations. The results indicate that (i) the model produced reliable results using the proposed approach; (ii) the influence of train load on the embankment was generally reflected in the upper part of the structure, and thus, bed structures are recommended to be strengthened; and (iii) under stationarity, the stiffness ratio between the bridge and normal subgrade is recommended as 1:6, with a transition length of 25 m.
Sustainable Evaluation of Major Third-Party Logistics Providers: A Framework of an MCDM-Based Entropy Objective Weighting Method
Authors: Wang Chia-Nan , Nguyen Ngoc-Ai-Thy , Dang Thanh-Tuan
Published: October 2023

This study aims to efficiently assist decision makers in evaluating global third-party logistics (3PL) providers from the perspectives of economic, social, and environmental sustainability and explore the determinants of the 3PL providers’ performance. In doing so, an integrated framework for an MCDM-based entropy objective weighting method is proposed for the first time in a logistics industry assessment. In the first stage, the entropy method defines the weight of the decision criteria based on real data collected from the top 15 global 3PL providers. This study lists the prominent quantitative evaluation criteria, taking into consideration the sustainability perspective. The advantage of the entropy method is that it reduces the subjective impact of decision makers and increases objectivity. In the second stage, the measurement of alternatives and ranking according to compromise solution (MARCOS) method is used to rank the 3PL providers according to their performance on the basis of these criteria. Sensitivity analysis and comparative analysis are implemented to validate the results. The current research work is devoted to the emerging research topic of sustainable development in the logistics industry and supply chain management. The proposed model identifies key performance indicators in the logistics industry and determines the most efficient 3PL providers. Consequently, the results show that the carbon dioxide emissions (20.50%) factor is the most important criterion for the competitiveness of global logistics companies. The results of this study can help inefficient 3PL providers make strategic decisions to improve their performance. However, this study only focuses on 15 companies due to a lack of data. The integration of these two techniques provides a novel way to evaluate global 3PL providers which has not been addressed in the logistics industry to date and as such remains a gap that needs to be investigated.
Research on Short-Term Passenger Flow Prediction of LSTM Rail Transit Based on Wavelet Denoising
Authors: Zhao Qingliang , Feng Xiaobin , Zhang Liwen , Wang Yiduo
Published: October 2023

Urban rail transit offers advantages such as high safety, energy efficiency, and environmental friendliness. With cities rapidly expanding, travelers are increasingly using rail systems, heightening demands for passenger capacity and efficiency while also pressuring these networks. Passenger flow forecasting is an essential part of transportation systems. Short-term passenger flow forecasting for rail transit can estimate future station volumes, providing valuable data to guide operations management and mitigate congestion. This paper investigates short-term forecasting for Suzhou’s Shantang Street station. Shantang Street’s high commercial presence and distinct weekday versus weekend ridership patterns make it an interesting test case, making it a representative subway station. Wavelet denoising and Long Short Term Memory (LSTM) were combined to predict short-term flows, comparing the results to those of standalone LSTM, Support Vector Regression (SVR), Artificial Neural Network (ANN), and Autoregressive Integrated Moving Average Model (ARIMA). This study illustrates that the algorithms adopted exhibit good performance for passenger prediction. The LSTM model with wavelet denoising proved most accurate, demonstrating applicability for short-term rail transit forecasting and practical significance. The research findings can provide fundamental recommendations for implementing appropriate passenger flow control measures at stations and offer effective references for predicting passenger flow and mitigating traffic pressure in various cities.
Voiceprint Recognition under Cross-Scenario Conditions Using Perceptual Wavelet Packet Entropy-Guided Efficient-Channel-Attention–Res2Net–Time-Delay-Neural-Network Model
Authors: Wang Shuqi , Zhang Huajun , Zhang Xuetao , Su Yixin , Wang Zhenghua
Published: October 2023

(1) Background: Voiceprint recognition technology uses individual vocal characteristics for identity authentication and faces many challenges in cross-scenario applications. The sound environment, device characteristics, and recording conditions in different scenarios cause changes in sound features, which, in turn, affect the accuracy of voiceprint recognition. (2) Methods: Based on the latest trends in deep learning, this paper uses the perceptual wavelet packet entropy (PWPE) method to extract the basic voiceprint features of the speaker before using the efficient channel attention (ECA) block and the Res2Net block to extract deep features. The PWPE block removes the effect of environmental noise on voiceprint features, so the perceptual wavelet packet entropy-guided ECA–Res2Net–Time-Delay-Neural-Network (PWPE-ECA-Res2Net-TDNN) model shows an excellent robustness. The ECA-Res2Net-TDNN block uses temporal statistical pooling with a multi-head attention mechanism to weight frame-level audio features, resulting in a weighted average of the final representation of the speech-level feature vectors. The sub-center ArcFace loss function is used to enhance intra-class compactness and inter-class differences, avoiding classification via output value alone like the softmax loss function. Based on the aforementioned elements, the PWPE-ECA-Res2Net-TDNN model for speaker recognition is designed to extract speaker feature embeddings more efficiently in cross-scenario applications. (3) Conclusions: The experimental results demonstrate that, compared to the ECAPA-TDNN model using MFCC features, the PWPE-based ECAPA-TDNN model performs better in terms of cross-scene recognition accuracy, exhibiting a stronger robustness and better noise resistance. Furthermore, the model maintains a relatively short recognition time even under the highest recognition rate conditions. Finally, a set of ablation experiments targeting each module of the proposed model is conducted. The results indicate that each module contributes to an improvement in the recognition performance.
Autoregression, First Order Phase Transition, and Stochastic Resonance: A Comparison of Three Models for Forest Insect Outbreaks
Authors: Soukhovolsky Vladislav , Kovalev Anton , Ivanova Yulia , Tarasova Olga
Published: October 2023

Three models of abundance dynamics for forest insects that depict the development of outbreak populations were analyzed. We studied populations of the Siberian silkmoth Dendrolimus sibiricus Tschetv. in Siberia and the Far East of Russia, as well as a population of the pine looper Bupalus piniarius L. in Thuringia, Germany. The first model (autoregression) characterizes the mechanism where current population density is dependent on population densities in previous k years. The second model considers an outbreak as analogous to a first-order phase transition in physical systems and characterizes the outbreak as a transition through a potential barrier from a low-density state to a high-density state. The third model treats an outbreak as an effect of stochastic resonance influenced by a cyclical factor such as solar activity and the “noise” of weather parameters. The discussion focuses on the prediction effectiveness of abundance dynamics and outbreak development for each model.
Dual-Neighborhood Search for Solving the Minimum Dominating Tree Problem
Authors: Pan Ze , Wu Xinyun , Xiong Caiquan
Published: October 2023

The minimum dominating tree (MDT) problem consists of finding a minimum weight subgraph from an undirected graph, such that each vertex not in this subgraph is adjacent to at least one of the vertices in it, and the subgraph is connected without any ring structures. This paper presents a dual-neighborhood search (DNS) algorithm for solving the MDT problem, which integrates several distinguishing features, such as two neighborhoods collaboratively working for optimizing the objective function, a fast neighborhood evaluation method to boost the searching effectiveness, and several diversification techniques to help the searching process jump out of the local optimum trap thus obtaining better solutions. DNS improves the previous best-known results for four public benchmark instances while providing competitive results for the remaining ones. Several ingredients of DNS are investigated to demonstrate the importance of the proposed ideas and techniques.
Kinematic Analysis of a Tendon-Driven Hybrid Rigid–Flexible Four-Bar; Application to Optimum Dimensional Synthesis
Authors: Hernández Alfonso , Muñoyerro Aitor , Urízar Mónica , Altuzarra Oscar
Published: October 2023

In design matters, mechanisms with deformable elements are a step behind those with rigid bars, particularly if dimensional synthesis is considered a fundamental part of mechanism design. For the purposes of this work, a hybrid rigid–flexible four-bar mechanism has been chosen, the input bar being a continuum tendon of constant curvature. The coupler curves are noticeably more complex but offer more possibilities than the classical rigid four-bar counterpart. One of the objectives of this work is to completely characterize the coupler curves of this hybrid rigid–flexible mechanism, determining the number and type of circuits as well as constituent branches. Another important aim is to apply optimization techniques to the dimensional synthesis of path generation. Considerable progress in finding the best design solutions can be obtained if all the acquired knowledge about the coupler curves of this hybrid mechanism is integrated into the optimization algorithm.
Young Duality for Variational Inequalities and Nonparametric Method of Demand Analysis in Input–Output Models with Inputs Substitution: Application for Kazakhstan Economy
Authors: Kerimkhulle Seyit , Obrosova Nataliia , Shananin Alexander , Tokhmetov Akylbek
Published: October 2023

The global macroeconomic shocks of the last decade entail the restructuring of national production networks and induce processes of input substitution. We suggest mathematical tools of Young duality for variational inequalities for studying these processes. Based on the tools we provide, a new mathematical model of a production network with several final consumers is created. The model is formulated as a pair of conjugated problems: a complementarity problem for optimal resource allocation with neoclassical production functions and the Young dual problem for equilibrium price indices on network products. The solution of these problems gives an equilibrium point in the space of network inter-industry flows and price indices on goods. Based on our previous results, we suggest an algorithm for model identification with an official economic statistic in the case of constant elasticity of substitution production functions. We give an explicit solution to the complementarity problems in this case and develop the algorithm of the inter-industry flows scenario projection. Since the algorithm needs the scenario projection of final sales structure as its input, we suggest a modified methodology that allows the calculation of scenario shifts in final consumer spending. To do this, we employ the generalized nonparametric method of demand analysis. As a result, we develop new technology for scenario calculation of a national input–output table, including shifts in final consumer spending. The technology takes into account a substitution of inputs in the network and is based on officially published national statistics data. The application of the methodology to study tax collection scenarios for Kazakhstan’s production network is demonstrated.
Application of LADMM and As-LADMM for a High-Dimensional Partially Linear Model
Authors: Feng Aifen , Chang Xiaogai , Fan Jingya , Jin Zhengfen
Published: October 2023

This paper mainly studies the application of the linearized alternating direction method of multiplier (LADMM) and the accelerated symmetric linearized alternating direction method of multipliers (As-LADMM) for high dimensional partially linear models. First, we construct a l1-penalty for the least squares estimation of partially linear models under constrained contours. Next, we design the LADMM algorithm to solve the model, in which the linearization technique is introduced to linearize one of the subproblems to obtain an approximate solution. Furthermore, we add the appropriate acceleration techniques to form the As-LADMM algorithm and to solve the model. Then numerical simulations are conducted to compare and analyze the effectiveness of the algorithms. It indicates that the As-LADMM algorithm is better than the LADMM algorithm from the view of the mean squared error, the number of iterations and the running time of the algorithm. Finally, we apply them to the practical problem of predicting Boston housing price data analysis. This indicates that the loss between the predicted and actual values is relatively small, and the As-LADMM algorithm has a good prediction effect.
Industrial Application of the ANFIS Algorithm—Customer Satisfaction Assessment in the Dairy Industry
Authors: Ljepava Nikolina , Jovanović Aleksandar , Aleksić Aleksandar
Published: October 2023

As a part of the food industry, the dairy industry is one of the most important sectors of the process industry, keeping in mind the number of employees in that sector, the share in the total industrial production, and the overall value added. Many strategies have been developed over time to satisfy customer needs and assess customer satisfaction. This paper proposes an innovative model based on adaptive neuro-fuzzy inference system (ANFIS) and elements of the ACSI (American customer satisfaction index) for assessing and monitoring the level of customer satisfaction in a dairy manufacturing company where there are no large seasonal variations. In terms of an innovative approach, the base of fuzzy logic rules is determined by applying the fuzzy Delphi technique for the application of the ANFIS algorithm and assessment of customer satisfaction. The verification of the model is delivered by testing a real sample from a company of the dairy industry. As decisions on the strategic company level may be impacted by customer satisfaction, the company management should choose the most precise methodology for customer satisfaction assessment. The results are compared with other methods in terms of mean absolute deviation (MAD), mean squared error (MSE), and mean absolute percentage error (MAPE). Results show that ANFIS outperformed other methods used for assessing the level of customer satisfaction, such as case-based reasoning and multiple linear regression.
A Hybrid Model to Explore the Barriers to Enterprise Energy Storage System Adoption
Authors: Liou James J. H. , Liu Peace Y. L. , Huang Sun-Weng
Published: October 2023

Using green energy is an important way for businesses to achieve their ESG goals and ensure sustainable operations. Currently, however, green energy is not a stable source of power, and this instability poses certain risks to normal business operations and manufacturing processes. The installation of energy storage equipment has become an indispensable accompaniment to facilitating green energy use for an enterprise. However, businesses may encounter significant barriers during the process of installing energy storage equipment. This study aims to explore and discern the key barrier factors that influence the assessment and decision-making process of installing energy storage equipment. A hybrid approach combining the Decision-making and Trial Evaluation Laboratory (DEMATEL) and Interpretive Structural Modeling (ISM) is developed to explore the causality relationships and degrees of influence among these key factors. The Z-number and Rough Dombi Weighted Geometric Averaging (RDWGA) methods are also utilized to integrate the experts’ varied opinions and uncertain judgements. Finally, recommendations are provided based on the results to assist businesses to make informed decisions while evaluating the installation of energy storage equipment, to ensure a stable and uninterrupted supply of green energy for use in normal operations.
Additional Value of Mini-Cog© in Urogeriatric Patients Concurrently Screened by G8 Scores
Authors: Bouzan Jobar , Willschrei Peter , Horstmann Marcus
Published: October 2023

Background: Cognitive impairment is poorly addressed in G8 screening. The aim of the present study was to evaluate the additional value of Mini-Cog© in urogeriatric patients concurrently screened by G8 scores. Methods: Seventy-four consecutive urogeriatric patients aged 75 and above were evaluated. All patients underwent G8 and Mini-Cog© screening. Patients with a G8 score above 14 were considered geriatric “healthy or fit”. A Mini-Cog© from four to five points was considered inconspicuous in screening for cognitive impairment. The additional information of a Mini-Cog© screening during G8 screening was evaluated by looking at G8 “fit and healthy” patients who had conspicuous Mini-Cog© tests and vice versa. Additionally, the results of the neuropsychological subitem “E” of the G8 score were compared with the results of the Mini-Cog© screening. Results: The mean age of the patients was 83 y (min. 75–max. 102). Sixty-one of the patients were males, and 13 were females. Twenty-nine of the patients had a normal G8 score and were considered “healthy or fit”, and 45 were not. Forty-three of the patients had an inconspicuous Mini-Cog©, and 31 had a conspicuous Mini-Cog© of less than four points. The majority of G8 “healthy or fit” patients (n = 24/29) had an inconspicuous Mini-Cog© test. However, of them, five patients had a Mini-Cog© of less than four points, which is suspicious for cognitive disorders. Furthermore, of the 43 patients with a normal G8 subscore in item “E” of two points, 6 patients had a conspicuous Mini-Cog© of less than four points. Conclusions: As shown by the present study, the Mini-Cog© might extend the G8 screening with regard to the detection of cognitive functional impairments that are not detected by the G8 screening alone. It can be easily added to G8 screening.
A Two-Dimensional K-Shell X-ray Fluorescence (2D-KXRF) Model for Soft Tissue Attenuation Corrections of Strontium Measurements in a Cortical Lamb Bone Sample
Authors: Gherase Mihai R.
Published: October 2023

Human bones store elements such as calcium, phosphorus, and strontium, and accumulate toxic elements such as lead. In vivo measurements of elemental bone concentration can be done using X-ray fluorescence (XRF) techniques. Monte Carlo (MC) simulations of X-ray interactions were predominantly employed in this field to develop calibration methods that linked XRF measurements to concentrations. A simple and fast two-dimensional K-shell X-ray fluorescence model was developed to compute the KXRF signal of elements in bone and overlying soft tissue samples. The model is an alternative to MC methods and can guide future bone XRF studies. Contours of bone and soft tissue cross sections were elliptical and only KXRF signals from absorption of primary photons were considered. Predictions of the model were compared to Sr KXRF measurements using the bare lamb bone (LB) and the LB with overlying leather. XRF experiments used a small X-ray beam, silicon X-ray detector, and three positioning stages. Linear attenuation coefficients of the leather and LB were measured and used in the model. Measured and model-derived values of the Sr X-rays leather attenuation and Sr Kβ/Kα ratio agreed, but estimated bone Sr concentrations were likely overestimated. Results, approximations, future work directions, and applications were discussed.
Exploring Microeukaryote Community Characteristics and Niche Differentiation in Arid Farmland Soil at the Northeastern Edge of the Tibetan Plateau
Authors: Chen Lingyun , Han Haifeng , Wang Chunhui , Warren Alan , Ning Yingzhi
Published: October 2023

The northeastern edge of the Tibetan Plateau exhibits diverse climate and landform variations, and has experienced substantial recent environmental changes, which may significantly impact local agricultural practices. Understanding the microeukaryote community structure within agricultural soils is crucial for finding out the biological responses to such changes and may guide future agricultural practices. In this study, we employed high-throughput amplicon sequencing to examine 29 agricultural soil samples from seven research areas around the northeastern edge of the Tibetan Plateau. The findings revealed that the predominant biological communities in these soils were characterized by a high abundance of Alveolata, Amoebozoa, and Rhizaria. Ascomycota displayed the highest relative abundance among fungal communities. Moreover, notable distinctions in microeukaryote community composition were observed among the study sites. Co-occurrence network analysis highlighted interactions between the biological communities. Furthermore, our results elucidated that deterministic and stochastic processes exerted diverse influences on the distribution of protozoan and fungal communities. This study provides valuable insight into the microeukaryote structure in the agricultural soils of the northeastern edge of the Tibetan Plateau, shedding light on the intricate relationships between environmental factors, microeukaryote communities, and agricultural productivity.
Mechanism of the Change in the Intestinal Microbiota of C-Strain Spodoptera frugiperda (Lepidoptera: Noctuidae) after an Interspecific Transference between Rice and Corn
Authors: Di Teng , Li Yongping , Du Guangzu , He Yanyan , Wang Wenqian , Shen Yunfeng , Meng Jizhi , Xiao Wenxiang , Xiao Guanli , Chen Bin
Published: October 2023

Spodoptera frugiperda (J.E.Smith) (Lepidoptera: Noctuidae) was first found in 2019 in Yunnan, China, and it was characterized as a corn strain; it was also found on rice strains there, and it damages rice in China, but little is known about the effect of host plant transfer on the intestinal microbiota and the activities of detoxification enzymes in the C-strain (corn strain) S. frugiperda. The intestinal microbiota and the protective enzyme activity of S. frugiperda that were transferred from rice plants were assessed, and the fourth generation of insects transferred from corn were studied; the gene types of S. frugiperda that were transferred from rice plants were tested using mitochondrial Tpi gene sequences. The results showed that the intestinal microbiota in the C-strain S. frugiperda were changed after the host transference, and the diversity and richness of the intestinal bacterial communities of the S. frugiperda feeding on rice were significantly reduced after the transfer of the host from corn. The predominant species of intestinal bacteria of the S. frugiperda on rice transferred from corn were Enterococcus and Enterobacter, with relative abundances of 28.7% and 66.68%; the predominant species of intestinal bacteria of the S. frugiperda that were transferred from rice and feeding on corn were Enterococcus (22.35%) and Erysipelatoclostridium (73.92%); and the predominant species of intestinal bacteria of S. frugiperda feeding on corn was Enterococcus, with a relative abundance of 61.26%. The CAT (catalase) activity of the S. frugiperda transferred from corn onto rice from corn was reduced, the POD (peroxidase) activity was significantly increased after the transfer from corn, and no significant variations were found for the SOD (superoxide dismutase), CarE (carboxylesterase), and GST (glutathione S-transferase) activities of S. frugiperda after the host plant transfer. The results showed that after feeding on rice, the activities of CAT and POD in the in S. frugiperda body changed in order to resist plant secondary metabolites from corn or rice, but there was no significant change in the detoxification enzymes in the body. In summary, switching the host plant between corn and rice induced variations in the intestinal microbiota in C-strain S. frugiperda owing to the strain difference between the C-strain and the R-strain (rice strain), and this was consistent with the results of the activities of detoxification enzymes. The results indicat that changes in intestinal microbiota and physiological enzymes may be important reasons for the adaptive capacity of C-strain S. frugiperda to rice.
Analysis of Microbial Diversity in South Shetland Islands and Antarctic Peninsula Soils Based on Illumina High-Throughput Sequencing and Cultivation-Dependent Techniques
Authors: Cui Siqi , Du Jie , Zhu Lin , Xin Di , Xin Yuhua , Zhang Jianli
Published: October 2023

To assess the diversity of bacterial taxa in Antarctic soils and obtain novel microbial resources, 15 samples from 3 sampling sites (DIS5, GWS7, FPS10) of South Shetland Islands and 2 sampling sites (APS18, CIS17) of Antarctic Peninsula were collected. High-throughput sequencing (HTS) of 16S rRNA genes within these samples was conducted on an Illumina Miseq platform. A total of 140,303 16S rRNA gene reads comprising 802 operational taxonomic units (OTUs) were obtained. After taxonomic classification, 25 phyla, 196 genera, and a high proportion of unidentified taxa were detected, among which seven phyla and 99 genera were firstly detected in Antarctica. The bacterial communities were dominated by Actinomycetota (40.40%), Pseudomonadota (17.14%), Bacteroidota (10.55%) and Chloroflexota (10.26%). Based on the HTS analyses, cultivation-dependent techniques were optimized to identify the cultivable members. A total of 30 different genera including 91 strains were obtained, the majority of which has previously been reported from Antarctica. However, for the genera Microterricola, Dyadobacter, Filibacter, Duganella, Ensifer, Antarcticirhabdus and Microvirga, this is the first report in Antarctica. In addition, seven strains represented novel taxa, two of which were psychropoilic and could be valuable resources for further research of cold-adaptability and their ecological significance in Antarctica.
Description of Aequorivita aurantiaca sp. nov. Isolated from Coastal Sediment, and Comparative Genomic Analysis and Biogeographic Distribution of the Genus Aequorivita
Authors: Liu Jun-Cheng , Ye Yu-Qi , Tan Xin-Yun , Du Zong-Jun , Ye Meng-Qi
Published: October 2023

A novel Gram-stain-negative, facultatively anaerobic, and non-motile bacterial strain, designated SDUM287046T, was isolated from the coastal sediments of Jingzi Port of Weihai, China. Cells of strain SDUM287046T were rod-shaped with widths of 0.4–0.5 μm and lengths of 0.7–1.4 μm and could produce flexirubin-type pigments. Optimum growth of strain SDUM287046T occurred at 33–35 °C, pH 7.0, and with 2% (w/v) NaCl. Oxidase activity was negative, but catalase activity was positive. Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain SDUM287046T was most closely related to Aequorivita aquimaris D-24T (98.3%). The main cellular fatty acids were iso-C15:0, anteiso-C15:0, iso-C17:0 3–OH, and summed feature 9 (comprised of iso-C17:1 ω9c and/or C16:0 10-methyl). The sole respiratory quinone was MK-6. The polar lipids consisted of phosphatidylethanolamine (PE), one aminolipid (AL), three unidentified glycolipids (GL), and three unidentified lipids (L). The DNA G + C content was 39.3 mol%. According to the integrated results of phylogenetic, physiological, biochemical, and chemotaxonomic characteristics, we propose that strain SDUM287046T represents a novel species of the genus Aequorivita, for which the name Aequorivita aurantiaca sp. nov. is proposed. The type strain is SDUM287046T (=KCTC 92754T = MCCC 1H01418T). Comparative genomic analysis showed that the 16 Aequorivita species shared 1453 core genes and differed mainly in amino acid metabolism, cofactor metabolism, and vitamin metabolism. Biogeographic distribution analysis indicated that the marine environments were the primary habitat of Aequorivita bacteria.
tilS and rpoB: New Molecular Markers for Phylogenetic and Biodiversity Studies of the Genus Thiothrix
Authors: Ravin Nikolai V. , Smolyakov Dmitry D. , Markov Nikita D. , Beletsky Alexey V. , Mardanov Andrey V. , Rudenko Tatyana S. , Grabovich Margarita Yu.
Published: October 2023

Currently, the phylogeny of the genus Thiothrix is based on comparative whole genome analysis because of the high homology of the 16S ribosomal RNA gene sequences within the genus. We analyzed the possibility of using various conservative genes as phylogenetic markers for the genus Thiothrix. We found that the levels of similarity of the nucleotide sequences of the tRNA(Ile)-lysidine synthase (tilS) and the β subunit of RNA polymerase (rpoB) genes are in good agreement with the average nucleotide identity (ANI) values between the genomes of various representatives of the genus Thiothrix. The genomes of Thiothrix strains MK1, WS, DNT52, DNT53, and H33 were sequenced. Taxonomic analysis using both whole genomes and the tilS gene consistently showed that MK1 and WS belong to Thiothrix lacustris, while DNT52, DNT53, and H33 belong to Thiothrix subterranea. The tilS gene fragments were subjected to high-throughput sequencing to profile the Thiothrix mat of a sulfidic spring, which revealed the presence of known species of Thiothrix and new species-level phylotypes. Thus, the use of tilS and rpoB as phylogenetic markers will allow for rapid analyses of pure cultures and natural communities for the purpose of phylogenetic identification of representatives of the genus Thiothrix.
Anti-Toxin Responses to Natural Enterotoxigenic Escherichia coli (ETEC) Infection in Adults and Children in Bangladesh
Authors: Girardi Petra , Bhuiyan Taufiqur Rahman , Lundin Samuel B. , Harutyunyan Shushan , Neuhauser Irene , Khanam Farhana , Nagy Gábor , Szijártó Valéria , Henics Tamás , Nagy Eszter , Harandi Ali M. , Qadri Firdausi
Published: October 2023

A sero-epidemiology study was conducted in Dhaka, Bangladesh between January 2020 and February 2021 to assess the immune responses to ETEC infection in adults and children. (1) Background: Enterotoxigenic Escherichia coli infection is a main cause of diarrheal disease in endemic countries. The characterization of the immune responses evoked by natural infection can guide vaccine development efforts. (2) Methods: A total of 617 adult and 480 pediatric diarrheal patients were screened, and 43 adults and 46 children (below 5 years of age) with an acute ETEC infection completed the study. The plasma samples were analyzed for antibody responses against the ETEC toxins. (3) Results: Heat-stable toxin (ST)-positive ETEC is the main cause of ETEC infection in adults, unlike in children in an endemic setting. We detected very low levels of anti-ST antibodies, and no ST-neutralizing activity. However, infection with ETEC strains expressing the heat-labile toxin (LT) induced systemic antibody responses in less than 25% of subjects. The antibody levels against LTA and LTB, as well as cholera toxin (CT), correlated well. The anti-LT antibodies were shown to have LT- and CT- neutralizing activity. The antibody reactivity against linear LT epitopes did not correlate with toxin-neutralizing activity. (4) Conclusions: Unlike LT, ST is a poor antigen and even adults have low anti-ST antibody levels that do not allow for the detection of toxin-neutralizing activity.
Comparison between Variable-Selection Algorithms in PLS Regression with Near-Infrared Spectroscopy to Predict Selected Metals in Soil
Authors: Abrantes Giovanna , Almeida Valber , Maia Angelo Jamil , Nascimento Rennan , Nascimento Clistenes , Silva Ygor , Silva Yuri , Veras Germano
Published: October 2023

Soil is one of the Earth’s most important natural resources. The presence of metals can decrease environmental quality if present in excessive amounts. Analyzing soil metal contents can be costly and time consuming, but near-infrared (NIR) spectroscopy coupled with chemometric tools can offer an alternative. The most important multivariate calibration method to predict concentrations or physical, chemical or physicochemical properties as a chemometric tool is partial least-squares (PLS) regression. However, a large number of irrelevant variables may cause problems of accuracy in the predictive chemometric models. Thus, stochastic variable-selection techniques, such as the Firefly algorithm by intervals in PLS (FFiPLS), can provide better solutions for specific problems. This study aimed to evaluate the performance of FFiPLS against deterministic PLS algorithms for the prediction of metals in river basin soils. The samples had their spectra collected from the region of 1000–2500 nm. Predictive models were then built from the spectral data, including PLS, interval-PLS (iPLS), successive projections algorithm for interval selection in PLS (iSPA-PLS), and FFiPLS. The chemometric models were built with raw data and preprocessed data by using different methods such as multiplicative scatter correction (MSC), standard normal variate (SNV), mean centering, adjustment of baseline and smoothing by the Savitzky–Golay method. The elliptical joint confidence region (EJCR) used in each chemometric model presented adequate fit. FFiPLS models of iron and titanium obtained a relative prediction deviation (RPD) of more than 2. The chemometric models for determination of aluminum obtained an RPD of more than 2 in the preprocessed data with SNV, MSC and baseline (offset + linear) and with raw data. The metals Be, Gd and Y failed to obtain adequate models in terms of residual prediction deviation (RPD). These results are associated with the low values of metals in the samples. Considering the complexity of the samples, the relative error of prediction (REP) obtained between 10 and 25% of the values adequate for this type of sample. Root mean square error of calibration and prediction (RMSEC and RMSEP, respectively) presented the same profile as the other quality parameters. The FFiPLS algorithm outperformed deterministic algorithms in the construction of models estimating the content of Al, Be, Gd and Y. This study produced chemometric models with variable selection able to determine metals in the Ipojuca River watershed soils using reflectance-mode NIR spectrometry.
Pharmacological Mechanisms and Adjuvant Properties of Licorice Glycyrrhiza in Treating Gastric Cancer
Authors: Tibenda Joanna Japhet , Du Yuhua , Huang Shicong , Chen Guoqing , Ning Na , Liu Wenjing , Ye Mengyi , Nan Yi , Yuan Ling
Published: October 2023

Licorice is a remarkable traditional Chinese medicine obtained from the dried root and rhizomes of the Glycyrrhiza genus, and t has been utilized in China for many centuries. It consists of more than 300 compounds that are mainly divided into triterpene saponins, flavonoids, polysaccharides, and phenolic components. The active compounds of licorice have been found to possess multiple biological activities, including antitumor, anti-inflammatory, antiviral, antimicrobial, immunoregulatory, cardioprotective, and neuroprotective functions. In addition to providing a brief overview of licorice’s adjuvant properties, this review describes and analyzes the pharmacological mechanisms by which licorice components function to treat gastric cancer. Furthermore, licorice compounds are also found to be potent adjuvant chemotherapy agents, as they can improve the quality of life of cancer patients and alleviate chemotherapy-induced adverse effects.
Sol–Gel Technologies to Obtain Advanced Bioceramics for Dental Therapeutics
Authors: Song Xiaozhe , Segura-Egea Juan J. , Díaz-Cuenca Aránzazu
Published: October 2023

The aim of this work is to review the application of bioceramic materials in the context of current regenerative dentistry therapies, focusing on the latest advances in the synthesis of advanced materials using the sol–gel methodology. Chemical synthesis, processing and therapeutic possibilities are discussed in a structured way, according to the three main types of ceramic materials used in regenerative dentistry: bioactive glasses and glass ceramics, calcium phosphates and calcium silicates. The morphology and chemical composition of these bioceramics play a crucial role in their biological properties and effectiveness in dental therapeutics. The goal is to understand their chemical, surface, mechanical and biological properties better and develop strategies to control their pore structure, shape, size and compositions. Over the past decades, bioceramic materials have provided excellent results in a wide variety of clinical applications related to hard tissue repair and regeneration. Characteristics, such as their similarity to the chemical composition of the mineral phase of bones and teeth, as well as the possibilities offered by the advances in nanotechnology, are driving the development of new biomimetic materials that are required in regenerative dentistry. The sol–gel technique is a method for producing synthetic bioceramics with high purity and homogeneity at the molecular scale and to control the surfaces, interfaces and porosity at the nanometric scale. The intrinsic nanoporosity of materials produced by the sol–gel technique correlates with the high specific surface area, reactivity and bioactivity of advanced bioceramics.
Chemistry of Carbon-Substituted Derivatives of Cobalt Bis(dicarbollide)(1−) Ion and Recent Progress in Boron Substitution
Authors: Pazderová Lucia , Tüzün Ece Zeynep , Bavol Dmytro , Litecká Miroslava , Fojt Lukáš , Grűner Bohumír
Published: October 2023

The cobalt bis(dicarbollide)(1−) anion (1−), [(1,2-C2B9H11)2-3,3′-Co(III)](1−), plays an increasingly important role in material science and medicine due to its high chemical stability, 3D shape, aromaticity, diamagnetic character, ability to penetrate cells, and low cytotoxicity. A key factor enabling the incorporation of this ion into larger organic molecules, biomolecules, and materials, as well as its capacity for “tuning” interactions with therapeutic targets, is the availability of synthetic routes that enable easy modifications with a wide selection of functional groups. Regarding the modification of the dicarbollide cage, syntheses leading to substitutions on boron atoms are better established. These methods primarily involve ring cleavage of the ether rings in species containing an oxonium oxygen atom connected to the B(8) site. These pathways are accessible with a broad range of nucleophiles. In contrast, the chemistry on carbon vertices has remained less elaborated over the previous decades due to a lack of reliable methods that permit direct and straightforward cage modifications. In this review, we present a survey of methods based on metalation reactions on the acidic C-H vertices, followed by reactions with electrophiles, which have gained importance in only the last decade. These methods now represent the primary trends in the modifications of cage carbon atoms. We discuss the scope of currently available approaches, along with the stereochemistry of reactions, chirality of some products, available types of functional groups, and their applications in designing unconventional drugs. This content is complemented with a report of the progress in physicochemical and biological studies on the parent cobalt bis(dicarbollide) ion and also includes an overview of recent syntheses and emerging applications of boron-substituted compounds.
Synthesis and Characterization of New Spirooxindoles Including Triazole and Benzimidazole Pharmacophores via [3+2] Cycloaddition Reaction: An MEDT Study of the Mechanism and Selectivity
Authors: Alshahrani Saeed , Al-Majid Abdullah , Alamary Abdullah , Ali M. , Altowyan Mezna , Ríos-Gutiérrez Mar , Yousuf Sammer , Barakat Assem
Published: October 2023

A new series of spirooxindoles based on benzimidazole, triazole, and isatin moieties were synthesized via a [3+2] cycloaddition reaction protocol in one step. The single X-ray crystal structure of the intermediate triazole-benzimidazole 4 was solved. The new chemical structures of these spirooxindole molecules have been achieved for the first time. The final synthesized chemical architecture has differently characterized electronic effects. An MEDT study of the key 32CA reaction between in situ generated azomethine ylide (AY) and chalcones explained the low reaction rates and the total selectivities observed. The supernucleophilic character of AY and the strong electrophilicity of chalcones favor these reactions through a highly polar two-stage one-step mechanism in which bond formation at the β-conjugated carbon of the chalcones is more advanced. The present combined experimental and theoretical study reports the synthesis of new spirooxindoles with potential biological activities and fully characterizes the molecular mechanisms for their formation through the key 32CA reaction step.
Reduced Graphene Oxide-Supported Iron-Cobalt Alloys as High-Performance Catalysts for Oxygen Reduction Reaction
Authors: Dong Jun , Wang Shanshan , Xi Peng , Zhang Xinggao , Zhu Xinyu , Wang Huining , Huang Taizhong
Published: October 2023

Exploring non-precious metal-based catalysts for oxygen reduction reactions (ORR) as a substitute for precious metal catalysts has attracted great attention in recent times. In this paper, we report a general methodology for preparing nitrogen-doped reduced graphene oxide (N–rGO)-supported, FeCo alloy (FeCo@N–rGO)-based catalysts for ORR. The structure of the FeCo@N–rGO based catalysts is investigated using X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, and transition electron microscopy, etc. Results show that the FeCo alloy is supported by the rGO and carbon that derives from the organic ligand of Fe and Co ions. The eletrocatalytic performance is examined by cyclic voltammetry, linear scanning voltammetry, Tafel, electrochemical spectroscopy impedance, rotate disc electrode, and rotate ring disc electrode, etc. Results show that FeCo@N–rGO based catalysts exhibit an onset potential of 0.98 V (vs. RHE) and a half-wave potential of 0.93 V (vs. RHE). The excellent catalytic performance of FeCo@N–rGO is ascribed to its large surface area and the synergistic effect between FeCo alloy and N–rGO, which provides a large number of active sites and a sufficient surface area.
Preventing Black Hole Attacks in AODV Using RREQ Packets
Authors: Nakano Yujin , Matsuzawa Tomofumi
Published: October 2023

Ad hoc networks, formed by multiple wireless communication devices without any connection to wired or intermediary devices such as by access points, are widely used in various situations to construct flexible networks that are not restricted by communication facilities. Ad hoc networks can rarely use existing infrastructure, and no authentication infrastructure is included in these networks as a trusted third party. Hence, distinguishing between ordinary and malicious terminals can be challenging. As a result, black hole attacks are among the most serious security threats to Ad hoc On-demand Distance Vector (AODV) routing, which is one of the most popular routing protocols in mobile ad hoc networks. In this study, we propose a defense method against black hole attacks in which malicious nodes are actively detected to prevent attacks. We applied the proposed method to a network containing nodes engaging in black hole attacks, confirming that the network’s performance is dramatically improved compared to a network without the proposed method.