bluuebunny/crossref_metadata_2025 huggingface dataset:
Antimicrobial Resistance Genes in Legionella from Artificial Water Systems: Findings from a Two-Year Study
Authors: Pereira Bernardo Beirão , Marrafa Mário , Cruz Carolina , Rodrigues Lúcia , Nunes Filipa , Monteiro Silvia , Santos Ricardo , Carneiro Rui Neves , Neto Célia , Aguilar Joana , Ferreiro Nuno Rafael , Passanha Margarida , Candeias Gonçalo , Fernandes Aida , Paixão Paulo , Chasqueira Maria Jesus
Published: November 2024

Background: Legionella species are the causative agent of Legionnaires’ disease and, as ubiquitous waterborne bacteria, are prone to antimicrobial resistance gene (ARG) acquisition and dissemination due to the antimicrobial contamination of natural environments. Given the potential health risks associated with ARGs, it is crucial to assess their presence in the Legionella population. Methods: The ARGs lpeAB and tet56 were detected in 348 samples, isolates, and DNA extracts using conventional PCR. In a subset of lpeAB-positive isolates, azithromycin (AZT) MIC values were obtained using the EUCAST protocol and LpeAB activity was evaluated through an efflux pump inhibition assay. Results: The lpeAB gene was found in 19% (66/348) of samples, with higher detection rates in the L. pneumophila and L. pneumophila sg1 subgroups, at 30% and 41%, respectively. A positive association between lpeAB and L. pneumophila sg1 was found. The MIC values of the lpeAB-positive isolates ranged from 0.064 to 2 mg/L. LpeAB inhibition resulted in 2- and 4-fold MIC reductions in 10 of the 13 isolates analyzed. One sample each of L. longbeacheae and L. bozemanae was found to possess the tet56 gene. Conclusions: The lpeAB gene is predominant in L. pneumophila sg1. A few isolates with the lpeAB gene exhibited MIC values below the EUCAST tentative highest MIC values for wild-type isolates. Expanding ARG monitoring in Legionella is essential to assess the public health risk of Legionnaires’ disease.
Metatranscriptomic Analysis Reveals Actively Expressed Antimicrobial-Resistant Genes and Their Hosts in Hospital Wastewater
Authors: Ota Yusuke , Chen Fei , Prah Isaac , Mahazu Samiratu , Watanabe Kimiyo , Kinoshita Teruaki , Gu Yoshiaki , Nukui Yoko , Saito Ryoichi
Published: November 2024

Antimicrobial resistance is a major global concern and economic threat, necessitating a reliable monitoring approach to understand its frequency and spread via the environment. Hospital wastewater serves as a critical reservoir for antimicrobial-resistant organisms; however, its role in resistance gene distribution and dissemination remains poorly understood. This study integrates metagenomic and metatranscriptomic analyses, elucidating the dynamics of antimicrobial resistance in hospital wastewater. Integrated metagenomic and metatranscriptomic sequencing were used to identify actively expressed antimicrobial-resistant genes and antimicrobial-resistant bacteria, offering comprehensive insights into antimicrobial resistance dynamics in hospital wastewater. Liquid chromatography–tandem mass spectrometry analysis revealed the presence of ampicillin, sulbactam, levofloxacin, sulfamethoxazole, and trimethoprim in the sample, which could apply selective pressure on antimicrobial resistance gene expression. While multidrug resistance genes were the most prevalent sequences in both metagenome-assembled genomes and plasmids, plasmid-derived sequences showed a high mRNA/DNA ratio, emphasizing the presence of functionally expressed antimicrobial resistance genes on plasmids rather than on chromosomes. The metagenomic and metatranscriptomic analyses revealed Serratia nevei MAG14 with high mRNA levels of antimicrobial resistance genes; moreover, multidrug-resistant Serratia sp., genetically related to MAG14, was isolated from the wastewater, supporting the phenotypic characterization of crucial antimicrobial-resistant bacteria and validating the genome analysis results. The findings underscore key genes and bacteria as targets for antimicrobial resistance surveillance in hospital wastewater to protect public and environmental health.
A Comparison of Causative Pathogens in Bone and Prosthetic Joint Infections: Implications for Antimicrobial Therapy
Authors: Unsworth Annalise , Young Bernadette , Scarborough Matthew , McNally Martin
Published: November 2024

Background: The microbiological profile of bone and joint infections is important for determining the empiric choice of both systemic and local antimicrobial therapy. This study assessed whether there was a difference in the bacterial species that were isolated on culture in osteomyelitis (OM), fracture-related infection (FRI) or prosthetic joint infection (PJI). This was a retrospective, observational cohort study of patients who had surgical intervention for PJI or OM or FRI with a positive microbial culture between 2019 and 2022. Methods: Data including patient demographics, the site of injury, JS-BACH score, organism classification and antibiotic resistance to vancomycin and gentamicin were extracted from the medical records. Results: A total of 440 patients were included in this study: 163 patients with osteomyelitis, 109 with fracture-related infection with fixation implants and 168 with prosthetic joint infection. The patients with PJI were older, more likely to be female and had a higher BMI and ASA score compared to those with OM. Patients with PJI were more likely to have a higher JS-BACH score and more complex infections. Staphylococcus aureus was the most commonly isolated organism in all three groups. It was more frequently isolated in osteomyelitis than in PJI (p = 0.016). In both osteomyelitis and FRI, after Staphylococcus aureus, the next most common organisms were Gram-negatives, whilst for PJIs, the most commonly isolated organisms were Staphylococcus aureus, followed by coagulase-negative Staphylococci and then Streptococcus species. The rates of other organisms were broadly similar between the three groups. When adjusted for confounders, including symptom duration, JS-BACH score, the location of injury, age and BMI, there was no statistically significant difference in the presence of Staphylococcus aureus (OR = 0.765; 95% CI 0.633–1.232; p = 0.465) or polymicrobial infection (OR = 1.175; 95% CI 0.803–1.721; p = 0.407). Conclusions: Causative pathogens are similar across bone and joint infections and are independent of the presence of prosthetic material.
Assessing the Reliability and Validity of a Questionnaire Evaluating Medical Students’ Attitudes, Knowledge, and Perceptions of Antibiotic Education and Antimicrobial Resistance in University Training
Authors: Vázquez-Cancela Olalla , Lens-Perol Guillermo , Mascareñas-Garcia Marta , Santana-Armas Magdalena , Vazquez-Lago Juan Manuel
Published: November 2024

The misuse and overuse of antibiotics represent a critical global issue and one of the most pressing public health challenges of the 21st century. Training future healthcare professionals effectively is essential for ensuring responsible antibiotic use. This study aimed to validate a questionnaire designed to evaluate the knowledge, attitudes, and perceptions of medical students regarding the education they receive on infectious diseases, antimicrobial resistance, and antibiotic stewardship during their university studies. Methods: A self-administered questionnaire was developed and distributed to medical students at the University of Santiago de Compostela. Comprising 44 items, the questionnaire assessed eight key dimensions: “infection diagnosis”, “criteria for not prescribing antibiotics”, “initial antibiotic therapy”, “re-evaluation of therapy”, “quality of care”, “communication skills”, “antibiotic resistance”, and “teaching methodology”. Validation was carried out in two stages: Phase 1 involved content and face validity, while Phase 2 focused on reliability analysis. Results: A total of 295 students completed the questionnaire, with a mean age of 23.15 ± 1.78 years. The sample included 86 male (29.2%) and 209 female (70.8%) respondents. Content and face validity were established by a nominal group of five experts and a focus group of medicine and pharmacy students to ensure consensus on item understanding in the Spanish language. The questionnaire demonstrated high internal consistency with a Cronbach’s alpha of 0.92 and satisfactory item discrimination. Construct validity was confirmed through principal component analysis, which supported the presence of the eight predefined dimensions. Conclusions: The validated questionnaire exhibited strong reliability and validity, making it a valuable tool for assessing medical students’ training in antibiotic-related topics. Its application will enable the identification of areas for improvement in university curricula, ultimately contributing to the promotion of appropriate antibiotic use and the reduction of antimicrobial resistance.
Cloning and Functional Analysis of Skin Host Defense Peptides from Yakushima Tago’s Brown Frog (Rana tagoi yakushimensis) and Development of Serum Endotoxin Detection System
Authors: Aono Taichi , Tamura Saki , Suzuki Yua , Imanara Taichi , Niwa Ryosei , Yamane Yoshie , Kobayashi Tetsuya , Kikuyama Sakae , Hasunuma Itaru , Iwamuro Shawichi
Published: November 2024

Background/Objective: Amphibian skin is a valuable source of host defense peptides (HDPs). This study aimed to identify HDPs with novel amino acid sequences from the skin of Rana tagoi yakushimensis and analyze their functions. Methods: cDNAs encoding HDP precursors were cloned and sequenced using RT-PCR and 3′-RACE. The novel HDPs were synthesized to evaluate their antimicrobial activity, antioxidant activity, and cytotoxicity. Antimicrobial activity was evaluated by way of broth microdilution and endotoxin- and β-glucan-binding capacity using an enzyme-linked endotoxin binding assay (ELEBA) and a modified ELEBA, respectively. Results: Nine cDNAs encoding precursors for various HDP families, including temporin, ranatuerin-2, brevinin-1, amurin-9, and a novel yakushimin peptide, were identified. Brevinin-1TYa exhibited antibacterial activity against Staphylococcus aureus, and brevinin-1TYa and amurin-9TYa induced morphological changes in Escherichia coli and S. aureus. Yakushimin-TYa, amurin-9TYa, and brevinin-1TYa showed concentration-dependent antibacterial effects against the plant pathogens Xanthomonas oryzae pv. oryzae and Clavibacter michiganensis subsp. michiganensis. Amurin-9TYa demonstrated strong binding affinity to lipopolysaccharide, lipoteichoic acid, and β-glucan, exhibited antioxidant activity, and lacked cytotoxicity, making it a promising therapeutic candidate. Moreover, brevinin-1TYa showed strong cytotoxicity, whereas yakushimin-TYa exhibited weak cytotoxicity. Conclusions: These findings highlight the potential of these peptides, particularly amurin-9TYa, for future applications as antimicrobial and therapeutic agents.
Pre- and Post-COVID-19 Antibiotic Consumption and Stewardship Program in a Southern Italian Hospital
Authors: Costantino Maria , Giudice Valentina , Campana Federica , Iannelli Alessandra Anna , Scala Pasqualina , Longanella Walter , Marongiu Francesco , Vozzella Emilia Anna , Elberti Maria Giovanna , Alfieri Maria , Boccia Giovanni , Conti Valeria , De Caro Francesco , Filippelli Amelia
Published: November 2024

Background/Objectives: Antibiotic resistance is a growing global threat that significantly impacts public health and healthcare costs. The Italian National Action Plan on Antimicrobial Resistance (PNCAR) was introduced in 2017 to address this issue by improving antibiotic stewardship. This study aimed to evaluate the effectiveness of the PNCAR in enhancing antibiotic management practices in a hospital in southern Italy before and after its implementation. Methods: We conducted an observational monocentric study to analyze antibiotic consumption in a hospital setting before and after the COVID-19 pandemic (2019 and 2023) and to examine prescription appropriateness and the types of used antibiotics. Results: After PNCAR introduction, we recorded a significant increase in antibiotic prescription appropriateness and in Access antibiotic and targeted therapy usage, while Reserve antibiotics were prescribed in ~10% of the cases, with an increasing trend in 2023. Conclusions: Our study supports the importance of targeted stewardship initiatives, including continuous monitoring and education, to sustain antibiotic prescription appropriateness and to reduce antimicrobial resistance.
Survival Strategies of Staphylococcus aureus: Adaptive Regulation of the Anti-Restriction Gene ardA-H1 Under Stress Conditions
Authors: de Andrade Flavia Costa Carvalho , Carvalho Mariana Fernandes , Figueiredo Agnes Marie Sá
Published: November 2024

Background/Objective: The anti-restriction protein ArdA-H1, found in multiresistant Staphylococcus aureus (MRSA) strains from the ST239-SCCmecIII lineage, inhibits restriction–modification systems, fostering horizontal gene transfer (HGT) and supporting genetic adaptability and resistance. This study investigates the regulatory mechanisms controlling ardA-H1 expression in S. aureus under various stress conditions, including acidic pH, iron limitation, and vancomycin exposure, and explores the roles of the Agr quorum sensing system. Methods: The expression of ardA-H1 was analyzed in S. aureus strains exposed to environmental stressors using real-time quantitative reverse transcription PCR. Comparisons were made between Agr-functional and Agr-deficient strains. In addition, Agr inhibition was achieved using a heterologous Agr autoinducing peptide. Results: The Agr system upregulated ardA-H1 expression in acidic and iron-limited conditions. However, vancomycin induced ardA-H1 activation specifically in the Agr-deficient strain GV69, indicating that an alternative regulatory pathway controls ardA-H1 expression in the absence of agr. The vancomycin response in GV69 suggests that diminished quorum sensing may offer a survival advantage by promoting persistence and HGT-related adaptability. Conclusion: Overall, our findings provide new insights into the intricate relationships between quorum-sensing, stress responses, bacterial virulence, and genetic plasticity, enhancing our understanding of S. aureus adaptability in challenging environments.
Diversity and Resistance Profiles of ESBL-Producing Gram-Negative Bacteria from Dairy Farms in Southern Türkiye
Authors: Kürekci Cemil , Yüksel Murat , Celil Ozaslan Büşra Gülay , Tan Sait , Jäckel Claudia , Grobbel Mirjam , Hammerl Jens Andre
Published: November 2024

Background/Objectives: The increasing occurrence of extended-spectrum β-lactamase (ESBL)–producing Enterobacterales, most commonly Escherichia coli, has become a serious problem. The aim of this study was to determine the presence of ESBL-producing Gram-negative bacteria in dairy cattle, goat and sheep farms located in southern Türkiye. Methods: Samples (409 quarter milk samples and 110 fresh faecal samples from cattle, 75 bulk tank milk samples and 225 rectal swab samples from goats and sheep) were subjected to selective isolation on MacConkey agar with ceftazidime (2 µg/mL). Isolates were identified by MALDI-ToF MS. The antimicrobial susceptibility profile of the isolates was determined by the broth microdilution method. To obtain a deeper insight into the genetic diversity of isolates substantially contributing to an efficient spread of their ESBL-determinants (23-MO00001: an E. coli from mastitis and 23-MO00002 Citrobacter freundii), the transmission potential and the genetic background of the plasmid carrying the blaCTX-M determinant was studied with whole genome analysis using Illumina sequencing. Results: Of the samples tested, 47 from the bovine faecal samples, 1 from the subclinical mastitis milk sample, 9 from the goat/sheep rectal swab samples and 5 from the goat/sheep bulk tank milk samples had ceftazidime-resistant Gram-negative strains with the ESBL phenotype. Of the 33 ESBL-producing E. coli isolates, 66.6% were resistant to tetracycline, 57.6% to sulfamethoxazole, 48.9% to nalidixic acid, 42.4% to ciprofloxacin and 33.3% to trimethoprim. Pulsed field gel electrophoresis (PFGE) results showed that the majority of E. coli isolates (16/33) and all Enterobacter spp. isolates (n = 5) were not clonally related (80% similarity cut value). The sequenced strains were observed to efficiently transfer their ceftazidime resistance to the recipient strain E. coli J53 at 37 °C (transfer rates: 101–102 transconjugants per donor cell). S1-PFGE showed that the transconjugants J53(p23MO01-T1) and J53(p23MO02-T1) had acquired plasmids of about 82 kb and 55 kb plasmids, respectively. According to WGS results, the E. coli isolate was assigned to ST162, while the C. freundii isolate was assigned to ST95. Conclusions: This study demonstrates that dairy animals are reservoirs of ESBL-producing bacteria.
Impact of Full-Spectrum and Infrared Lighting on Growth, Oxidative Stress, and Cecal Microbiota in Broilers
Authors: Hayat Khawar , Zheng Rongjin , Zeng Li , Ye Zunzhong , Pan Jinming
Published: November 2024

Lighting is crucial for the development of broilers as it affects their growth performance, oxidative stress, and overall health. This study investigates the impact of full-spectrum light, infrared light, and LED white light exposure on the growth performance, oxidative stress markers, and cecal microbiota of medium-growth yellow-feathered broilers. A total of 216 medium-growth yellow-feathered chicks (Yuhuang No. 5), five days old, were randomly divided into three groups: 72 chicks in each group, with three replicates of 24 chicks. The birds were raised under different lighting conditions, including LED infrared light (II), full-spectrum therapy light (FB), and LED white light (CG) until day 87. This experiment comprised the early growth phase and measured critical hormones such as Melatonin (Mel), Growth Hormone (GH), and Growth Hormone Releasing Hormone (GHRH), as well as Malondialdehyde (MDA), Superoxide Dismutase (SOD), and Catalase (CAT). Additionally, this study examined the differences in microbiota diversity and composition. The results demonstrated that LED infrared and full-spectrum light exposure significantly (p < 0.05) increased broiler body weight. Particularly, full-spectrum light was effective in comb redness and reducing final comb length and oxidative stress. Furthermore, full-spectrum light improved microbial prosperity and diversity compared with the other lighting conditions. Overall, the findings suggest that full-spectrum lighting is more beneficial for broiler growth, reducing oxidative stress, and promoting gut health compared with LED infrared lighting. These insights can be applied to optimizing broiler farming practices, thereby improving productivity and animal welfare.
Protective Effects of L-Cysteine Against Cisplatin-Induced Oxidative Stress-Mediated Reproductive Damage
Authors: Chiang Yi-Fen , Chen Yi-Tzu , Huang Ko-Chieh , Hung Wei-Lun , Chung Cheng-Pei , Shieh Tzong-Ming , Huang Yun-Ju , Ali Mohamed , Hsia Shih-Min
Published: November 2024

Cisplatin (CIS) is a widely used chemotherapeutic agent, but its side effects, such as oxidative stress, inflammation, and apoptosis, often lead to male reproductive damage. Oxidative stress, primarily caused by the excessive generation of reactive oxygen species (ROS), plays a critical role in disrupting testicular homeostasis, resulting in spermatogenic impairment and tissue injury. L-cysteine (CYS), a semi-essential amino acid with potent antioxidant and anti-inflammatory properties, may offer protection against CIS-induced oxidative damage. This study aimed to assess the protective potential of CYS against CIS-induced male reproductive toxicity using in vivo and in vitro models. In vitro, treatment of TM3 (Leydig) and TM4 (Sertoli) cells with CIS led to increased ROS levels, reduced cell viability, and elevated apoptosis and inflammation, all of which were significantly ameliorated by subsequent CYS exposure. In vivo, CIS-treated male rats displayed heightened oxidative stress, impaired spermatogenesis, and histopathological damage in reproductive organs. However, CYS administration for 21 days significantly reduced oxidative stress, improved sperm viability, and protected testicular tissues from damage. These findings suggest that CYS has a protective effect against CIS-induced oxidative stress and male reproductive damage, making it a promising therapeutic agent for mitigating CIS-induced reproductive toxicity.
MnSOD Mimetics in Therapy: Exploring Their Role in Combating Oxidative Stress-Related Diseases
Authors: Grujicic Jovan , Allen Antiño R.
Published: November 2024

Reactive oxygen species (ROS) are double-edged swords in biological systems—they are essential for normal cellular functions but can cause damage when accumulated due to oxidative stress. Manganese superoxide dismutase (MnSOD), located in the mitochondrial matrix, is a key enzyme that neutralizes superoxide radicals (O2•−), maintaining cellular redox balance and integrity. This review examines the development and therapeutic potential of MnSOD mimetics—synthetic compounds designed to replicate MnSOD’s antioxidant activity. We focus on five main types: Mn porphyrins, Mn salens, MitoQ10, nitroxides, and mangafodipir. These mimetics have shown promise in treating a range of oxidative stress-related conditions, including cardiovascular diseases, neurodegenerative disorders, cancer, and metabolic syndromes. By emulating natural antioxidant defenses, MnSOD mimetics offer innovative strategies to combat diseases linked to mitochondrial dysfunction and ROS accumulation. Future research should aim to optimize these compounds for better stability, bioavailability, and safety, paving the way for their translation into effective clinical therapies.
Ginsenoside Rg1 Alleviates Blood–Milk Barrier Disruption in Subclinical Bovine Mastitis by Regulating Oxidative Stress-Induced Excessive Autophagy
Authors: Yang Shanshan , Fang Zihao , Duan Hongwei , Dong Weitao , Xiao Longfei
Published: November 2024

As a critical disease usually infected by Staphylococcus aureus, with a worldwide effect on dairy animals, subclinical mastitis is characterized by persistence and treatment resistance. During mastitis, the blood–milk barrier (BMB)’s integrity is impaired, resulting in pathogen invasion and milk quality decline. In this study, it was found that ginsenoside Rg1 (Rg1), a natural anti-inflammatory and antioxidant compound derived from ginseng, inhibited the onset of tight junction (TJ) dysfunction and ameliorated lipoteichoic acid (LTA)-induced BMB disruption inside and outside the organisms. According to subsequent mechanistic studies, Rg1 inhibited excessive autophagy and inactivated the NLRP3 inflammasome by blockading ROS generation, thereby alleviating TJ dysfunction. Peroxisome proliferator-activated receptor gamma (PPARγ) was identified as a potential target of Rg1 by means of molecular docking plus network pharmacology analysis. Furthermore, it was demonstrated that Rg1 inhibited the oxidative stress levels by activating PPARγ, and regulating the upstream autophagy-related AMPK/mTOR signaling pathway, thus decreasing excessive in vivo and in vitro autophagy. The ROS/autophagy/NLRP3 inflammasome axis was identified as a promising target for treating subclinical bovine mastitis in this study. In conclusion, Rg1 is proven to alleviate BMB disruption by activating PPARγ to inhibit oxidative stress and subsequent excessive autophagy in the case of subclinical bovine mastitis.
Phenolic Content and Anti-Inflammatory Activity of Cultivated and Wild-Type Galium odoratum Extracts in Murine Bone Marrow-Derived Macrophages
Authors: Razzivina Valerija , Vasiljeva Anna , Kronberga Arta , Skudrins Gundars , Nakurte Ilva , Zogota Marta , Mezaka Ieva , Pugovics Osvalds , Grinberga Solveiga , Dambrova Maija , Sile Inga
Published: November 2024

Galium odoratum, commonly known as sweet woodruff, is a perennial herbaceous plant that contains coumarin and is recognized for its medicinal properties. In this study, the influence of sunlight exposure on the phytochemical composition and anti-inflammatory potential of G. odoratum extracts is assessed. The extracts from cultivated and wild-grown plants were analyzed via chromatographic and mass spectrometric methods. In addition, the total phenolic content, antioxidant activity, and effects on macrophage polarization were assessed. The results revealed that while coumarin levels remain stable regardless of environmental conditions, phenolic content and antioxidant activity increase significantly under sun-grown conditions, with chlorogenic acid and rutin identified as major contributing compounds. Additionally, the extracts exhibited anti-inflammatory activity, effectively reducing the M1 macrophage population involved in inflammatory responses. These findings suggest that controlled sunlight exposure can enhance the bioactive profile of G. odoratum. This research highlights the critical role of environmental management in optimizing the medicinal properties of G. odoratum, providing a foundation for its future use in natural therapeutic applications.
Lithocholic Acid’s Ionic Compounds as Promising Antitumor Agents: Synthesis and Evaluation of the Production of Reactive Oxygen Species (ROS) in Mitochondria
Authors: Chobanov Nuri M. , Dzhemileva Lilya U. , Dzhemilev Usein M. , D’yakonov Vladimir A.
Published: November 2024

The development of a methodology for the synthesis of new compounds with antitumor activity represents a significant and priority task within the field of medicinal chemistry. As a continuation of our research group’s earlier studies on the antitumor activity of ionic derivatives of natural compounds, we have synthesized a series of previously undescribed pyrazole ionic compounds through a series of transformations of lithocholic acid methyl ester. To investigate the biological activity of the newly synthesized lithocholic acid derivatives, a series of modern flow cytometry techniques were employed to assess their cytotoxic activity, effects on the cell cycle, and induction of apoptosis. This included the analysis of alterations in the mitochondrial potential, accumulation of ROS ions in mitochondria, and loss of cytochrome c. These compounds demonstrate promising antitumor activity through their effects on mitochondrial oxidation and phosphorylation processes. These compounds, which we have designated as “soft dissociators”, exhibit enhanced biopharmacological properties relative to the original lithocholic acid molecule.
Experimental and LES Study of H2/CH4 Premixed Gas Deflagration Under Different Obstacle Conditions
Authors: Han Yanan , Gao Jianfeng , Wu Yang , Shao Xiaojun , Peng Shuxuan
Published: November 2024

To study the influence of obstacles on the premixed gas explosion process and provide a theoretical basis for the safe use of fuel and the space configuration within weakly constrained structures, experimental and numerical simulation studies were conducted to investigate the explosion behavior of H2/CH4 premixed gas under different obstacle conditions. According to the angle and position of obstacles, 12 explosion working conditions were set up, and the flame kinetic behavior under the combined influence was obtained. The results show that increasing the direct contact area between the obstacle and the flame near the ignition source can effectively reduce the explosion effect. The explosion consequence is most serious when the obstacle is located in the middle position of the weakly constrained structure. When the obstacle is close to the vent, the later the flame reaches the vent, the more the explosion pressure peaks, and the explosion impact decreases as the angle of the obstacle decreases. In the numerical simulation, it was also found that when the flame passes through the obstacle near the ignition source, it takes on a special “jellyfish” shape toward the vent. In conclusion, the results of the study are useful for making reasonable assumptions about the location of the ignition source and the presence of obstacles based on the degree of damage to the weakly confined structure caused by the premixed gas explosion.
Research Progress of Zero-Busbar Technology Based on Heterojunction Photovoltaic Modules
Authors: Zhang Shu , Chen Xue , Chu Haiyuan , Guo Xian , Xie Yan , Fan Xiyan , Li Runtao , Zhu Jian , Tan Jiabin , Yang Jiyuan , Chen Yifeng , Gao Jifan
Published: November 2024

In order to reduce manufacturing costs, the design of silicon-based solar modules is changing from a super-multi-busbar design to a zero-busbar (0BB) design. In this study, two different 0BB technologies based on heterojunction with intrinsic thin-layer solar cells—conventional soldering, and Integrated Film Covering (IFC)—were investigated. IFC-based 0BB technology was found to have a lower contact resistance, which well matches the theoretical calculations and module power testing results. To further measure module reliability, a series of tests on solders and silver pastes were carried out. The results show that Sn43Pb43Bi14 solder is more suitable for soldering-based 0BB technology, whereas Sn32Pb42Bi26 solder is more suitable for IFC-based technology. Additionally, silver paste, which is used for solder ribbon contact areas (SRCAs), is suitable for soldering-based 0BB technology. When Ag@Cu paste is used in SRCAs with IFC-based 0BB technology, a reliable connection can also be achieved. After optimization, modules using both techniques were subjected to and passed lifetime tests, including the thermal cycling, humidity freeze, and hot-spot tests required in IEC standards, as well as more rigorous tests such as thermal–dynamic and thermal–static mechanical loading. The results show that the two technologies have great potential for future mass production.
Intelligent Perception and Seam Tracking System for Thick Plate Weldments Based on Constant-Focus Optical Path
Authors: Zhai Lei , Ren Wenze , Li Fei , Wu Rong , Lin Jinsong , Feng Jiahui , Zheng Jun , Liu Yang
Published: November 2024

To achieve efficient and accurate thick plate welding, as well as to precisely extract and plan the paths of complex three-dimensional weld seams in large steel structures, this study introduces a novel vision-guided approach for robotic welding systems utilizing a constant-focus laser sensor. This methodology specifically targets and mitigates several critical shortcomings inherent in conventional vision-guided welding techniques, including limited detection ranges, diminished precision in both detection and tracking, and suboptimal real-time performance. For preprocessed weld images, an improved grayscale extreme centroid method was developed to extract the center of the light stripe. Furthermore, a sophisticated feature point extraction algorithm, which integrates a maximum distance search strategy with a least-squares fitting procedure, was developed to facilitate the precise and timely identification of weld seam characteristic points. To further optimize the outcomes, a cylindrical filtering mechanism was employed to eliminate substantial discrepancies, whereas local Non-Uniform Rational B-Spline (NURBS) curve interpolation was utilized for the generation of smooth and accurate trajectory plans. A spatial vector-based pose adjustment strategy was then implemented to provide robust guidance for the welding robot, ensuring the successful execution of the welding operations. The experimental results indicated that the proposed algorithm achieved a tracking error of 0.3197 mm for welding workpieces with a thickness of 60 mm, demonstrating the method’s substantial potential in the manufacturing sector, especially in the domain of automated welding.
Fixed-Bed Columns of Avocado (Persea americana Hass.) Seed and Peel Biomass as a Retainer for Contaminating Metals
Authors: Gómez-Naranjo Andrés , Mayorga-Naranjo Cristina , Vélez-Terreros Pamela Y. , Yánez-Jácome Gabriela S. , Oviedo-Chávez Augusto , Navarrete Hugo , Vinueza-Galáraga Julio , Romero-Estévez David
Published: November 2024

This study evaluated the adsorbent capacity of the Ecuadorian avocado (Persea americana Hass.) seed and peel wastes as an alternative method for cadmium (Cd), mercury (Hg), lead (Pb), and nickel (Ni) ion removal from aqueous solutions. The laboratory microscale process was performed using fixed-bed columns containing 1 g of 600 μm particles of biomaterial pretreated with ethanol and ethylene glycol. Subsequently, metal solutions of different concentrations were eluted and measured by flame atomic absorption spectroscopy. Results showed that fixed-bed columns allow efficient adsorption of Pb (2.6 mg/g) with ethanol pretreatment. Lower adsorption capacity was achieved for Cd, Hg, and Ni ions. Favorable adsorption with high retention capacity was found for Pb+2 for the ethanol pretreated bio-adsorbent at higher concentrations (120 mg/L). Lower removal percentages were found for Cd+2, Hg+2, and Ni+2; Ni showed the lowest adsorption capacities and negative RL values, suggesting inefficient adsorbent development. Regeneration of Cd, Hg, and Pb ions from avocado peel and seed showed the highest recovery when 1 mol/L HCl solution was used. Regarding the adsorption isotherms, the Langmuir model was the one that best fit our data, demonstrating that adsorption takes place in a uniform monolayer and that each contaminant ion occupies a single site.
The Role of Fermented Vegetables as a Sustainable and Health-Promoting Nutritional Resource
Authors: Borrego-Ruiz Alejandro , González-Domenech Carmen M. , Borrego Juan J.
Published: November 2024

The increasing global burden of morbidity and mortality from chronic diseases related to poor diet quality, coupled with the unsustainable depletion of vital planetary resources by current food production systems, threatens future food security and highlights the urgent need to transition to high-quality plant-based diets as a viable solution to mitigate economic, health, and environmental challenges. Taking into consideration the significant role that fermented vegetables may play as a sustainable, healthy, long-lasting, and plant-based nutritional resource, this narrative review analyzes their production and benefits. For this purpose, the mechanisms of the fermentation process are explored, along with the importance of probiotic cultures in plant-based fermented foods, and with the implications of fermentation on food safety within the broader framework of low-impact, organic, plant-derived nutrition. Additionally, the health benefits of fermented vegetables and probiotics are examined, including their effects on mental health. Vegetable fermentation is a versatile method for enhancing food preservation, nutritional quality, and safety. This ancient practice prolongs the shelf life of perishable items, reduces the toxicity of raw ingredients, and improves digestibility. Specific starter cultures, particularly lactic acid bacteria, are essential for controlling fermentation, ensuring safety, and maximizing health benefits. Fermented vegetables, rich in probiotics, support gut health and immune function. Emerging research indicates their potential to alleviate adverse mental health symptoms such as stress and anxiety, highlighting their significance in modern dietary guidelines and chronic health management.
Identifying Soil Erosion-Prone Areas in the Wadi Haly Catchment, Saudi Arabia Using Morphometric Analysis and Watershed Features
Authors: Bashir Bashar , Alsalman Abdullah
Published: November 2024

Soil erosion has several significant impacts on human and environmental activities that make it an important topic with significant worldwide ramifications. Analyzing morphometric indices provides essential insights into watershed geomorphology, which is key to forecasting and assessing diverse natural hazard dynamics. To ensure effective and sustainable watershed management and resource distribution, it is essential to identify critical catchments or prioritize sub-catchments. In this study, morphometric analysis and prioritization were applied to 15 sub-catchments within the Wadi Haly catchment to identify the one most susceptible to soil erosion. This research focuses on the analysis of 15 sub-catchments within the Wadi Haly catchment in Saudi Arabia, utilizing GIS tools alongside various parameters to guide both short- and long-term catchment management. A combined parameter, developed from several morphometric indices for each sub-catchment, was used to classify the Wadi Haly catchment into three levels of soil erosion risk. The results show that sub-catchments 1, 7, 11, 12, and 13, with areas of 694.1 km2, 517.87 km2, 677.99 km2, 200.39 km2, and 326.55 km2, respectively, are contributing significantly to erosion in the region. In contrast, sub-catchments 3, 8, 9, 10, and 15 exhibit minimal erosion impact. To mitigate severe erosion, strategies such as contour farming, terracing, the use of filter strikes, as well as various structural or non-structural interventions could be applied.
Optimization Method for Improving Efficiency of Thermal Field Reconstruction in Concrete Dam
Authors: Xiang Yunfei , Lin Peng , Peng Haoyang , Li Zichang , Liu Yuanguang , Qiao Yu , Yang Zuobin
Published: November 2024

In an actual concrete dam construction, the efficiency of thermal field reconstruction directly affects the timeliness of temperature control measures. Therefore, using lightweight methods to obtain real-time, accurate thermal fields is crucial for concrete temperature control. To balance both accuracy and efficiency, this study proposes an optimization method for thermal field reconstruction in concrete dams. The method consists of three components: evaluating interpolation algorithms, optimizing the number of monitoring points, and analyzing their positions. Specifically, a distributed temperature sensing system is employed for concrete monitoring, with a “Z-shaped” optical fiber layout. Three interpolation algorithms—Kriging, Natural Neighbor, and Inverse Distance Weighting—are quantitatively evaluated, with Kriging showing the highest accuracy. Sensitivity analysis, combined with the control variable method, is used to assess the impact of the monitoring point number and position. Lightweight application procedures are then proposed, using reconstructed thermal field results to guide strategy formulation and parameter adjustment for the intelligent cooling control system. A case study demonstrates that this method ensures the effectiveness and timeliness of concrete temperature control measures. The proposed approach enables real-time updates of concrete temperature control measures in sync with the progress of the pouring process, providing a valuable reference for similar projects.
Artificial Intelligence for Earthquake Prediction: A Preliminary System Based on Periodically Trained Neural Networks Using Ionospheric Anomalies
Authors: Baselga Sergio
Published: November 2024

There is increasing evidence that anomalies in the ionosphere could appear a few days before large earthquakes. Many significant successes with using anomalies for predictions have been reported, although they are usually limited, both in space, to a specific geographic area, and in time, to one or a few events. To date, no solution has been presented that consistently yields the location and magnitude of future earthquakes and thus can be used to develop a warning service. The purpose of this research is to improve on the possible use of Global Ionospheric Maps for earthquake prediction. The use of three-dimensional data matrices, having spatiotemporal information to feed a convolutional neural network, is proposed in this contribution. This network was trained on all large earthquakes occurring from the beginning of the year 2011 to the beginning of October 2024 but it is proposed that it be periodically retrained with new data. This network has reached an accuracy of around 60% in the validation data for a division into eight categories of different earthquake magnitudes. Nevertheless, this percentage increases considerably if the classification into neighboring categories is also accepted, something that could be clearly admissible for the purposes of a warning system. The author believes that success in this endeavor has to come from a collaborative effort. For this reason, the training and validation data with three-dimensional matrices (latitude/longitude/time) of total electron content values along with the subsequent earthquake magnitudes are provided in this paper along with the trained network. Researchers are strongly encouraged to improve on the current neural network with or without the inclusion of additional information.
Carbon Dioxide Hydrate Formation in Porous Media Under Dynamic Conditions for CO2 Storage in Low-Temperature Water Zones
Authors: Mahmood Md Nahin , Islam Muhammad Towhidul , Guo Boyun
Published: November 2024

Injecting carbon dioxide (CO2) into subsea water zones, where the in situ temperatures are below the hydrate-forming temperature of CO2, has been recently proposed to lock CO2 inside the water zones in a solid hydrate form. It is a common concern that CO2 may form hydrates during the injection period, which would reduce well injectivity. CO2 injection into sandstone cores under simulated subsea temperatures ranging from 0 °C to 5 °C was investigated in this study. Experimental results show that flowing CO2 at Darcy velocity 0.033 cm/s begins to form hydrate in the sandstone core at dynamic pressures higher than the minimum required pressure under static conditions. At temperatures changing from 0 °C to 5 °C, the observed hydrate-forming pressure changes from 1.87 to 2.5 times the pressures required for CO2 hydrates under static conditions. The reason why the required minimum pressure for CO2 to form hydrates in dynamic conditions is higher than that in static conditions is attributed to the shear rate effect of flowing fluids that should slow down the growth of hydrate crystals and/or break down formed hydrate films in the dynamic conditions. Therefore, higher pressure energy, or fugacity, is required to promote the growth of hydrate crystals and hydrate films in dynamic conditions. More rigorous investigations in this area are needed in the future.
A Meta-Analysis of the Review Literature on Multiple-Criteria Decision Aids for Environmental Issues
Authors: Digkoglou Panagiota , Tsoukiàs Alexis , Papathanasiou Jason , Gotzamani Katerina
Published: November 2024

Environmental decision making is a complex process that requires the consideration of multiple factors. Therefore, Multiple-Criteria Decision Aiding (MCDA) aims to address the challenges of environmental decision making. This paper analyses published review papers that discuss the use of MCDA in environmental problems, with the goal of drawing useful meta-level conclusions. The review papers were categorised by application field and sorted by various criteria. The main findings of each paper were also analysed. The analysis reveals that MCDA publications in the specific domain have shown a strong upward trend. Hybrid MCDA is increasingly being applied as it can cope with the multidimensional challenges of environmental decision making. AHP appears to be the most widespread method. The sustainable energy sector is particularly interested in the use of MCDA. However, while decision-makers extensively use MCDA in environmental problems, its corresponding application in real-world settings is not always satisfactory.
Analysis of Production Process Parameters Using Computer Simulation at the Planning Stage
Authors: Pawlak Szymon , Małysa Tomasz , Fornalczyk Agnieszka
Published: November 2024

Computer simulation is one of the tools that is often used to support activities related to the management of the production process. Computer simulation allows for the analysis of the parameters of production or logistics processes, among others. The study presents a comparative analysis of analytical methods and computer simulation (FlexSim 22.2.1 software) in relation to the subject matter. The use of computer simulation allowed for the verification of the number of production resources, determined by analytical methods, and for the proposal of improvements that would allow for shortening the duration of the production process and reducing its costs. The proposed improvements at the stage of planning the production process in terms of the number of production resources used to implement the assumed production plan allowed for the reduction of the duration of the production process and its costs. Therefore, it is justified to use computer simulation in solving problems related to various aspects of the functioning of an enterprise.
Application of Natural and Modified Zeolite Sediments for the Stabilization of Cadmium and Lead in Contaminated Mining Soil
Authors: Alotaibi Sami S. , Ibrahim Hesham M. , Alghamdi Abdulaziz G.
Published: November 2024

Soil contamination by many kinds of anthropogenic operations, such as industrial and mining activities, results in the accumulation of various heavy metal contaminants in the environment. Cadmium (Cd) and lead (Pb) are commonly found heavy metals in the Mahad Adahab mining area in Saudi Arabia. In this study, natural and modified zeolite sediments were fractioned by size to nano- and macrosizes and were applied to stabilize Cd and Pb from contaminated mining soil. Among the tested adsorbents, zeolite sediment in the nanosize that was modified by layered double hydroxides (LDH-N) showed the highest sorption and removal efficiency (>98%) for Cd and Pb, followed by nanosized natural zeolite (NZ-N) and HCl-modified nanosized natural zeolite sediment (HCl-N), which removed >90% Cd and Pb from contaminated soil. A pH of 7 was found to be optimal for Cd and Pb sorption, and the kinetics study revealed that first-order and pseudo-second-order kinetic models best fitted the experimental data (R2 = 0.94–0.98) for Cd and Pb sorption by the tested sediments. An incubation period of 16 weeks revealed that LDH-N, HCl-N, and NZ-N reduced the ammonium acetate extractable fraction of Cd by 89.26, 83.70, and 80.54% and Pb by 86.19, 81.42, and 77.98%, respectively. Electrostatic interaction and ion exchange were found to be the principal mechanisms for Cd and Pb sorption. The findings of this study indicate that the utilization of modified zeolite sediment in the nanosize fraction (LDH-N, HCl-N, and NZ-N) could be an effective and feasible strategy in stabilizing heavy metals and mitigating their toxicity in contaminated mining soil.
Dynamic Spectrum Co-Access in Multicarrier-Based Cognitive Radio Using Graph Theory Through Practical Channel
Authors: Badran Ehab F. , Bashir Amr A. , Kheirallah Hassan Nadir , Farag Hania H.
Published: November 2024

In this paper, we propose an underlay cognitive radio (CR) system that includes subscribers, termed secondary users (SUs), which are designed to coexist with the spectrum owners, termed primary users (PUs). The suggested network includes the PUs system and the SUs system. The coexistence between them is achieved by using a novel dynamic spectrum co-access multicarrier-based cognitive radio (DSCA-MC-CR) technique. The proposal uses a quadrature phase shift keying (QPSK) modulation technique within the orthogonal frequency-division multiplexing (OFDM) scheme that maximizes the system data rate and prevents data inter-symbol interference (ISI). The proposed CR transmitter station (TX) and the CR receiver node (RX) can use an advanced smart antenna system, i.e., a multiple-input and multiple-output (MIMO) system that provides high immunity against channel impairments and provides a high data rate through its different combining techniques. The proposed CR system is applicable to coexist within different existing communication applications like fifth-generation (5G) applications, emergence applications like the Internet of Things (IoT), narrow-band (NB) applications, and wide-band (WB) applications. The coexistence between the PUs system and the SUs system is based on using power donation from the SUs system to improve the quality of the PU signal-to-interference-and-noise ratios (SINRs). The green communication concept achieved in this proposal is compared with similar DSCA proposals from the literature. The simulations of the proposed technique show enhancement in the PUs system throughput and data rate along with the better performance of the SUs system.