bluuebunny/crossref_metadata_2025 huggingface dataset:
Stratification Effects on Estuarine Mixing: Comparative Analysis of the Danshui Estuary and a Thermal Discharge Outlet
Authors: Zhong Yaozhao , Chien Hwa
Published: December 2024

Estuaries serve as transitional zones between rivers and the ocean, and their mixed dynamic characteristics are crucial for the transport, transformation, and cycling of materials. This study investigates the mixing characteristics and their dominant factors in the Danshui Estuary and thermal discharge outlets through field measurements. Based on CTD (Conductance Temperature Depth) profiles and nutrient concentration measurements, the Danshui Estuary exhibited significant stratification during the October 2016 cruise, while vertical mixing was uniform during the March 2017 cruise. Vertical mixing was suppressed during stratification, but the nutrient concentration varied with salinity in a manner that was similar to non-stratified conditions, generally conforming to the theoretical dilution curve, which means physical mixing dominated here, indicating that horizontal mixing is predominant in the Danshui Estuary. The spatial scale calibrated horizontal dispersion coefficients were measured as 9.16 ± 1.57 m2 s−1 and 11.84 ± 1.71 m2 s−1 for stratified and non-stratified conditions, respectively, highlighting the Danshui Estuary’s strong horizontal mixing. Thermal discharge outlets are an important type of estuarine environment in non-natural estuaries. The 3D thermohaline structure measured by the underway CTD revealed an upwelling of cold and high-salinity water during the flood tide. The calculated Richardson number during the flood tide was approximately 0.7, indicating a very strong stratification effect. The horizontal dispersion coefficients calibrated by spatial scale showed no significant difference between different tides (flood tide: 0.53 ± 0.18 m2 s−1, ebb tide: 0.46 ± 0.17 m2 s−1). Therefore, the slower temperature decay during the flood tide, as reflected by the e-folding time (flood tide: 4.19 ± 2.33 min, ebb tide: 2.14 ± 0.40 min), is attributed to the strong stratification. Based on these findings, it is recommended that the power plant mitigates the impact of waste heat on the marine environment by increasing discharge during the ebb tide and reducing it during the flood tide.
Horizontal-Transverse Coherence of Bottom-Received Acoustic Field in Deep Water with an Incomplete Sound Channel
Authors: Wang Qianyu , Peng Zhaohui , Zhang Bo , Zhu Feilong , Luo Wenyu , Wang Tongchen , Zhang Lingshan , Mao Junjie
Published: December 2024

The horizontal-transverse coherence of low-frequency (300 Hz) and long-range (10–40 km) acoustic fields near the bottom in deep water is investigated based on experimental data obtained from the South China Sea. The results indicate that the horizontal-transverse coherence length exhibits a strong dependence on the source-receiver distance, with fluctuations consistent with sound intensity trends. In high-intensity regions, the horizontal-transverse coherence is relatively high, with a coherence length exceeding 600 λ, where λ is the acoustic wavelength, whereas in low-intensity regions, the horizontal-transverse coherence decreases significantly, with the coherence length shortening to 10–30 λ. The physical mechanisms underlying the horizontal-transverse coherence are analyzed using the ray theory. In high-intensity regions, the energy of the dominant ray (the ray with the highest energy) accounts for over 70% of the total energy of the rays, exerting a decisive influence on the coherence coefficient and leading to stable horizontal-transverse coherence in the received acoustic field. In contrast, in low-intensity regions, the energy distribution is dispersed, and when amplitude and phase disturbances due to spatial inhomogeneity are introduced, the horizontal coherence deteriorates significantly. The numerical simulations are also performed, and the results are consistent with the experimental observations.
Underwater SSP Measurement and Estimation: A Survey
Authors: Huang Wei , Wu Pengfei , Lu Jiajun , Lu Junpeng , Xiu Zhengyang , Xu Zhenpeng , Li Sijia , Xu Tianhe
Published: December 2024

Real-time and accurate construction of regional sound speed profiles (SSPs) is important for building underwater positioning, navigation, and timing (PNT) systems as it greatly affects signal propagation modes. In this paper, we summarize and analyze the current research status in the field of underwater SSP construction, where the mainstream methods include direct SSP measurement and SSP inversion. For the direct measurement method, we compare the performance of popular international and commercial brands of temperature, conductivity, and depth profilers (CTDs). For the inversion methods, the framework and basic principles of matched field processing (MFP), compressive sensing (CS), and deep learning (DL) are introduced, and their advantages and disadvantages are compared. Presently, SSP inversion relies on sonar observation data, limiting its applicability to areas that can only be reached by underwater observation systems. Furthermore, these methods are unable to predict the distribution of sound velocity in future time. Therefore, the mainstream trend in future research on SSP construction will involve comprehensive utilization of multi-source data to offer elastic sound velocity distribution estimation services for underwater users without the need for sonar observation data.
Spatiotemporal Variability of Anthropogenic Film Pollution in Avacha Gulf near the Kamchatka Peninsula Based on Synthetic-Aperture Radar Imagery
Authors: Bondur Valery , Chernikova Vasilisa , Chvertkova Olga , Zamshin Viktor
Published: December 2024

The paper addresses the spatiotemporal variability of anthropogenic film pollution (AFP) in Avacha Gulf near the Kamchatka Peninsula based on satellite synthetic-aperture radar (SAR) imagery. Coastal waters of the study area are subject to significant anthropogenic impacts associated with intensive marine traffic, as well as the flow of household and industrial wastewater from factories located on the coast. A quantitative approach to the registration and quantitative analysis of spatiotemporal AFP distributions was applied. This approach is based on the processing of long-term time series of SAR imagery, taking into account inhomogeneous observation coverage and changing hydrometeorological conditions of different regions of water areas in various time periods. In total, 318 cases of AFP were detected in 2014–2023 in Avacha Gulf, covering 332 km2 of the total area (~3% of the water area) based on the 1134 processed radar Sentinel-1A/B scenes. The average value of AFP exposure, e, was about 93 ppm, evidencing the high level of AFP in the studied water area (comparable to areas of the Black Sea with intensive marine traffic, for which e was previously determined to be between ~90 and ~130 ppm). An interannual positive trend was revealed, indicating that over the 10-year period under study, the exposure of the waters of Avacha Bay (the most polluted part of Avacha Gulf) to AFP increased ~3-fold. An analysis of AFP spatial distributions and marine traffic maps indicates that this type of activity is a significant source of anthropogenic film pollution in Avacha Gulf (including Avacha Bay). It was shown that the generated quantitative information products using the introduced AFP exposure concept can be interpreted and used, for example, for making management decisions.
A Design-Oriented Model for Transmission Loss Optimization in Marine DOCs
Authors: Kašpar Jan , Mauro Francesco , Biot Marco , Rognoni Giovanni , Kyaw Oo D’Amore Giada
Published: December 2024

The even more restrictive regulations imposed on chemical and acoustic emissions of ships necessitate the installation of after-treatment systems onboard. The spaces onboard are limited, and the Exhaust Gas Cleaning Systems (EGCSs) have big dimensions, so an appropriate integration and optimization of EGCSs allows to save space and comply with international regulations. Moreover, in the available literature, there is a lack of guidelines about the design of integrated EGCSs. This study aims to develop an ad hoc optimization methodology that uses combined Computational Fluid Dynamics (CFD)–Finite Element Method (FEM) simulations, surrogate models, and Genetic Algorithms to optimize the acoustic properties of EGCSs while considering the limits imposed by the efficiency of chemical reactions for the abatement of NOx and SOx. The developed methodology is applied to a Diesel Oxidation Catalyst (DOC), and the obtained results lead to a system that integrates the silencing effect into the DOC.
Dual-Branch Feature Generalization Method for AUV Near-Field Exploration of Hydrothermal Areas
Authors: Liu Yihui , Chen Guofang , Xu Yufei , Wan Lei , Zhang Ziyang
Published: December 2024

The simultaneous localization and mapping (SLAM) technique provides long-term near-seafloor navigation for autonomous underwater vehicles (AUVs). However, the stability of descriptors generated by interest point detectors remains a challenge in the hydrothermal environment. This paper proposes a dual-branch feature generalization method, incorporating volumetric density and color distribution for enhanced robustness. The method utilizes shared descriptors and a feature confidence mechanism, combining neural radiance fields with Gaussian splatting models, ensuring fast and accurate feature generalization. The proposed approach improves recall while maintaining matching accuracy, ensuring stability and robustness in feature matching. This method achieves stable and reliable feature matching in a simulated hydrothermal environment.
Reliability of Inland Water Transportation Complex Network Based on Percolation Theory: An Empirical Analysis in the Yangtze River
Authors: Han Dong , Sui Zhongyi , Xiao Changshi , Wen Yuanqiao
Published: December 2024

Inland water transportation is regarded as a crucial component of global trade, yet its reliability has been increasingly challenged by uncertainties such as extreme weather, port congestion, and geopolitical tensions. Although substantial research has focused on the structural characteristics of inland water transportation networks, the dynamic responses of these networks to disruptions remain insufficiently explored. This gap in understanding is critical for enhancing the resilience of global transportation systems as trade volumes grow and risks intensify. In this study, percolation theory was applied to evaluate the reliability of the Yangtze River transportation network. Ship voyage data from 2019 were used to construct a complex network model, and simulations of node removal were performed to identify key vulnerabilities within the network. The results showed that the failure of specific nodes significantly impacts the network’s connectivity, suggesting which nodes should be prioritized for protection. This research offers a dynamic framework for the assessment of inland water transportation network reliability and provides new insights that could guide policy decisions to improve the resilience of critical waterway systems. By identifying potential points of failure, this study contributes to the development of a more robust global trade infrastructure.
Analysis of Deep-Sea Acoustic Ranging Features for Enhancing Measurement Capabilities in the Study of the Marine Environment
Authors: Dolgikh Grigory , Morgunov Yuri , Golov Aleksandr , Burenin Aleksandr , Shkramada Sergey
Published: December 2024

This article explores the features of using hydroacoustic methods to measure and monitor climate-induced temperature variations along acoustic paths in the Sea of Japan. It delves into effective techniques for controlling and positioning of deep-sea autonomous measuring systems (DSAMS) for diverse applications. Theoretical and experimental findings from research conducted in the Sea of Japan in August 2023 along a 144.4 km acoustic route under summer–autumn hydrological conditions, including the aftermath of the powerful typhoon “Khanun”, are presented. The main hydrological regime characteristics for this period are compared with data obtained in 2022. This study explores the transmission of pulsed pseudorandom signals from a broad shelf into the deep area of the sea, with receptions occurring at depths of 69, 126, 680, and 914 m. An experiment was conducted to receive broadband pulse signals centered at a frequency of 400 Hz, located 144.4 km from the source of navigation signals (SNS), which is positioned on the shelf at a depth of 30 m in waters that are 45 m deep. A system of hydrophones, deployed to depths of up to 1000 m, was utilized to capture signal data, allowing for prolonged recording at fixed depths or during descent. An analysis of the experimentally acquired impulse characteristics revealed a series of ray arrivals lasting approximately 0.5 s, with a peak consistently observed across all depths. Findings from both full-scale and numerical experiments enabled the assessment of impulse characteristics within an acoustic waveguide, the calculation of effective signal propagation speeds at varying depths, and the development of conclusions regarding the viability of tackling control and positioning challenges for DSAMS at depths reaching up to 1000 m and distances spanning hundreds of kilometers from control stations.
A Novel Hull Girder Design Methodology for Prediction of the Longitudinal Structural Strength of Ships
Authors: Yu Haicheng , Wu Songhao , Zhao Yingdong , Liu Wenlong , Yang Haiyi
Published: December 2024

The ship hull girder model has been widely adopted in ship mechanics research such as small-scale and large-scale hydroelastic ship model experiments. Current design methods cannot seriously meet the structural rigidity requirement, and the distinction between the ship structural masses and the cargo masses is rather vague. This research proposes a simple and novel ship hull girder design methodology. The main novelties are that (1) the structural rigidity design requirement for the ship hull girder corresponding to any targeted real ship with arbitrary structural complexity is precisely satisfied by the proposed strategy of adopting a composite hull girder system, and that (2) the mass density per unit length of the proposed hull girder is solely related to the mass density distribution of the targeted ship structures by considering the hull girder system as a complete finite element (FE) model, and thus (3) a better ship hull girder model for prediction of the total structural responses can be consequently established. A real ship is adopted as the design target, and the structural responses of the real ship and the proposed ship hull girder model are compared and analyzed. The proposed model is compared to the currently widely accepted ship hull girder models through numerical experiments. The proposed hull girder design methodology possesses the potential for upgrading the classical structural design approach to match the growing trend of adopting FEM-based approaches for ship structure research.
Typhoon Effects on Surface Phytoplankton Biomass Based on Satellite-Derived Chlorophyll-a in the East Sea During Summer
Authors: Jung HwaEun , Ahn JiSuk , Kang Jae Joong , Hwang Jae Dong , Youn SeokHyun , Oh HyunJu , Joo HuiTae , Kim Changsin
Published: December 2024

The East Sea is a jointly managed maritime area of Korea, Russia, and Japan, where the frequency of strong typhoons is anticipated to increase with climate change, affecting its marine ecosystem and regional climate regulation. This study investigated the environmental and ecological impacts of summer typhoons entering the East Sea by analyzing satellite-derived chlorophyll-a (Chl-a) data, Argo float measurements, and ERA5 wind data. Our findings revealed that summer typhoons generally increased surface Chl-a concentrations by 65.4%, with typhoon intensity substantially influencing this process. Weak typhoons caused marginal Chl-a increases attributed to redistribution rather than nutrient supply, whereas normal and strong typhoons increased Chl-a through enhanced vertical mixing and nutrient upwelling in the East Sea. Stronger typhoons notably impacted the mixed layer depth and isothermal layer depth, leading to greater Chl-a concentrations within the strong wind radius. However, the increased Chl-a magnitude was lower than that of other strong typhoons in other regions. The East Sea uniquely responds to typhoons with fewer upper environment changes, possibly due to a stable barrier layer limiting vertical mixing. These findings underscore the importance of continuous monitoring and integrated observational methods in order to better understand the ecological effects of typhoons, particularly as their intensity increases with climate change.
High-Intensity Focus Ultrasound Ablation in Prostate Cancer: A Systematic Review
Authors: Yang Che-Hsueh , Barbulescu Daniela-Viviana , Marian Lucian , Tung Min-Che , Ou Yen-Chuan , Wu Chi-Hsiang
Published: December 2024

Background/Objectives: Prostate cancer (PCa) outcomes vary significantly across risk groups. In early-stage localized PCa, the functional outcomes following radical prostatectomy (RP) can be severe, prompting increased interest in focal therapy, particularly High-Intensity Focused Ultrasound (HIFU). This study is to summarize the current clinical trials of HIFU on PCa. Methods: We reviewed clinical trials from major databases, including PubMed, MEDLINE, Scopus, and EMBASE, to summarize the current research on HIFU in PCa treatment. Results: The literature highlights that HIFU may offer superior functional outcomes, particularly in continence recovery, compared to RP and radiation therapy. However, the oncological efficacy of HIFU remains inadequately supported by high-quality studies. Focal and hemigland ablations carry a risk of residual significant cancer, necessitating comprehensive patient counseling before treatment. For post-HIFU monitoring, we recommend 3T magnetic resonance imaging (MRI) with biopsy at 6 to 12 months to reassess the cancer status. Biochemical recurrence should be defined using the Phoenix criteria, and PSMA PET/CT can be considered for identifying recurrence in biopsy-negative patients. Conclusions: Whole-gland ablation is recommended as the general approach, as it provides a lower PSA nadir and avoids the higher positive biopsy rates observed after focal and hemigland ablation in both treated and untreated lobes. Future study designs should address heterogeneity, including variations in recurrence definitions and surveillance strategies, to provide more robust evidence for HIFU’s oncological outcomes.
Opportunities and Challenges of Chatbots in Ophthalmology: A Narrative Review
Authors: Sabaner Mehmet Cem , Anguita Rodrigo , Antaki Fares , Balas Michael , Boberg-Ans Lars Christian , Ferro Desideri Lorenzo , Grauslund Jakob , Hansen Michael Stormly , Klefter Oliver Niels , Potapenko Ivan , Rasmussen Marie Louise Roed , Subhi Yousif
Published: December 2024

Artificial intelligence (AI) is becoming increasingly influential in ophthalmology, particularly through advancements in machine learning, deep learning, robotics, neural networks, and natural language processing (NLP). Among these, NLP-based chatbots are the most readily accessible and are driven by AI-based large language models (LLMs). These chatbots have facilitated new research avenues and have gained traction in both clinical and surgical applications in ophthalmology. They are also increasingly being utilized in studies on ophthalmology-related exams, particularly those containing multiple-choice questions (MCQs). This narrative review evaluates both the opportunities and the challenges of integrating chatbots into ophthalmology research, with separate assessments of studies involving open- and close-ended questions. While chatbots have demonstrated sufficient accuracy in handling MCQ-based studies, supporting their use in education, additional exam security measures are necessary. The research on open-ended question responses suggests that AI-based LLM chatbots could be applied across nearly all areas of ophthalmology. They have shown promise for addressing patient inquiries, offering medical advice, patient education, supporting triage, facilitating diagnosis and differential diagnosis, and aiding in surgical planning. However, the ethical implications, confidentiality concerns, physician liability, and issues surrounding patient privacy remain pressing challenges. Although AI has demonstrated significant promise in clinical patient care, it is currently most effective as a supportive tool rather than as a replacement for human physicians.
Hemogram-Based Phenotypes of the Immune Response and Coagulopathy in Blunt Thoracic Trauma
Authors: Băetu Alexandru Emil , Mirea Liliana Elena , Cobilinschi Cristian , Grințescu Ioana Cristina , Grințescu Ioana Marina
Published: December 2024

Background: Blunt thoracic trauma possesses unique physiopathological traits due to the complex interaction of immune and coagulation systems in the lung tissue. Hemogram-based ratios such as neutrophil-to-lymphocyte (NLR), platelet-to-lymphocyte (PLR), neutrophil-to-lymphocyte × platelet (NLPR) ratios have been studied as proxies for immune dysregulation and survival in trauma. We hypothesized that blunt thoracic trauma patients exhibit distinct patterns of coagulation and inflammation abnormalities identifiable by the use of readily available hemogram-derived markers. Methods: The present study represents a retrospective observational analysis that included 86 patients with blunt thoracic trauma from a single high-volume level one trauma center. The primary outcome was mortality prediction in blunt thoracic trauma patients using these derived biomarkers. Secondary outcomes included phenotypes of the immune response and coagulopathy and the prediction of non-fatal adverse events. Results: A U-shaped distribution of mortality was found, with high rates of early deaths in patients with an NLPR value of <3.1 and high rates of late deaths in patients with NLPR > 9.5. A subgroup of blunt thoracic trauma patients expressing moderate inflammation and inflammation-induced hypercoagulation objectified as NLPR between 3.1 and 9.5 may have a survival benefit (p < 0.0001). The NLPR cut-off for predicting early deaths and the need for massive transfusion was 3.1 (sensitivity = 80.00% and specificity = 71.05%). Conclusions: These findings suggest that blunt thoracic trauma patients exhibit distinct phenotypes of the immune response and coagulopathy from the early stages. A controlled, balanced interaction of immune, coagulation, and fibrinolytic systems might effectively achieve tissue repair and increase survival in thoracic trauma patients and should be subject to further research.
Auditors’ Perceptions of the Triggers and Obstacles of Continuous Auditing and Its Impact on Auditor Independence: Insights from Egypt
Authors: Aladwey Laila Mohamed Alshawadfy , Sayad Samar El
Published: December 2024

Our study explores auditors’ perceptions of the triggers and hurdles of implementing continuous auditing (CA) in Egypt. It also explores auditors’ perceptions of the impact of CA on their independence. A survey of ninety-five auditors working in Big Four and non-Big Four firms was conducted to gather data. Descriptive statistics and the Friedman test were used to test our hypotheses. In addition, using the Mann–Whitney U test, we delve deeper into auditors’ perceptions to examine differences across audit firm types. The results reveal that addressing the increasing demand of stakeholders for real-time reporting and enhancing the quality of financial reporting significantly affect auditors’ perceptions of the triggers for adopting CA. In addition, the lack of standards related to CA and the high cost of implementation significantly affect auditors’ perceptions of the obstacles to implementing CA. The lack of clear guidelines regarding the work required in CA and auditing data that the auditors have previously corrected during the CA process is perceived by auditors as among the most significant factors that can impair their independence. The significance of this study stems from the fact that it is one of the few studies to explore continuous auditing practices in developing countries. To the best of our knowledge, this study is one of the first to investigate how CA affects auditor independence in developing countries.
Impact of Farmer Cooperatives on Labor Employment: Evidence from Rural China
Authors: Qiu Yutong , Bai Yunli , Wu Jiaojiao , Zeng Xuanye , Zhang Linxiu
Published: December 2024

Farmer cooperatives are one of the types of important entities for agricultural production and rural community development in China. This study aims to examine the effects of farmer cooperatives on rural labor employment and explores the mechanisms from the perspective of institutional advantage, factor redistribution, and value chain. Leveraging two-waved panel data from the China Rural Development Survey, a multinomial Logit model and Tobit model with panel data are adopted. The results show that farmer cooperatives significantly boost rural labor employment, with a more pronounced effect on fully farming and part-time farming. These effects are primarily seen through three mechanisms: income augmentation stemming from institutional advantages, factor redistribution by land transferring and technology service/adoption, as well as industrial clusters. The limited value chain extension of farmer cooperatives hinders its role in improving fully non-agricultural employment. The findings suggest that the government should support the high-quality development of farmer cooperatives to facilitate rural labor employment.
Integrative Framework for Decoding Spatial and Temporal Drivers of Land Use Change in Malaysia: Strategic Insights for Sustainable Land Management
Authors: Ye Guanqiong , Chen Kehao , Yang Yiqun , Liang Shanshan , Hu Wenjia , He Liuyue
Published: December 2024

Identifying the drivers of land use and cover change (LUCC) is crucial for sustainable land management. However, understanding spatial differentiation and conducting inter-regional comparisons of these drivers remains limited, particularly in regions like Malaysia, where complex interactions between human activities and natural conditions pose significant challenges. This study presents a novel analytical framework to examine the spatial variations and complexities of LUCC, specifically addressing the spatiotemporal patterns, driving factors, and pathways of LUCC in Malaysia from 2010 to 2020. Integrating the land use transfer matrix, GeoDetector model, and Structural Equation Modeling (SEM), we reveal a significant expansion of farmland and urban areas alongside a decline in forest cover, with notable regional variations in Malaysia. Human-driven factors, such as population growth and economic development, are identified as the primary forces behind these changes, outweighing the influence of natural conditions. Critically, the interactions among these drivers exert a stronger influence on LUCC dynamics in Malaysia than any single factor alone, suggesting increasingly complex LUCC predictions in the future. This complexity emphasizes the urgency of proactive, multifaceted, and region-specific land management policies to prevent irreversible environmental degradation. By proposing tailored land management strategies for Malaysia’s five subnational regions, this study addresses spatial variations in drivers and climate resilience, offering a strategic blueprint for timely action that can benefit Malaysia and other regions facing similar challenges in sustainable land management.
How Has Land Restriction Policy Influenced Green Total Factor Productivity? Evidence from Chinese Cities
Authors: Xu Shengyan , Liu Miao , Hua Ping , Chen Yibo
Published: December 2024

In 2014, China implemented a policy to limit land supply for new industrial construction in city centers with more than 5 million people to decrease the pollution of urban areas caused by industrialization. We aimed to study whether this land restriction policy (LRP) has been conducive to enhancing urban green total factor productivity (GTFP) with the goal of achieving long-term sustainable urban development. We formulated our hypotheses based on theoretical analysis. We used the difference-in-differences method and the data from prefecture-level cities from 1999 to 2017 for verification. The findings indicate that the LRP has improved the urban GTFP via (1) increasing the allocation efficiency of land transfer; (2) increasing land prices and transforming the industrial structure to tertiary industry; and (3) decreasing newly built firms, investments, patents for inventions, and technological innovation. Consequently, a selected land policy favoring green industry is required to prevent urban deindustrialization and to support the sustainable industrial development of the urban economy throughout the low-carbon transition.
Localization of Secondary Metabolites in Relict Gymnosperms of the Genus Sequoia In Vivo and in Cell Cultures In Vitro, and the Biological Activity of Their Extracts
Authors: Kirakosyan Rima N. , Kalasnikova Elena A. , Bolotina Elizaveta A. , Saleh Abdulrahman , Balakina Anastasiya A. , Zaytseva Svetlana M.
Published: December 2024

In order to scientifically search for new sources of secondary metabolites with valuable qualities for phytopharmacognosy, tasks requiring a step-by-step solution were set. The primary task is the development of technologies for obtaining in vitro highly productive biomass of cells of relict gymnosperms of the genus Sequoia, capable of accumulating various classes of secondary metabolites. The study of the accumulation and localization of secondary metabolites allowed us to evaluate the biological activity and cytotoxicity of in vitro Sequoia cultures. In our study, histochemical methods were used to determine the localization of secondary compounds (phenolic and terpenoid in nature) in plant tissues. Secondary metabolites—polyphenols, catechins, and terpenoids—are mainly localized in the epidermal, parenchymal, and conductive tissues of Sequoia leaves and stems. In callus and suspension cultures of Sequoia, secondary metabolites were localized in cell walls and vacuoles. The mineral composition of the nutrient medium (MS and WPM), the light source (photoperiod), and the endogenous content of polyphenols in the primary explant influenced the initiation and growth characteristics of the in vitro culture of Sequoia plants. Inhibition of growth in suspension cultures on the WPM nutrient medium was noted. The cultivation of Sequoia cell lines at a 16 h photoperiod stimulated the formation of polyphenols but had a negative effect on the growth of callus cultures. Extractive substances obtained from intact and callus tissues of evergreen Sequoia demonstrate high biological (fungicidal) activity and cytotoxicity. The inhibitory effect on Fusarium oxisporum was noted when 200 mg/L of Sequoia extract was added to the nutrient medium. Extracts of redwood callus cultures were low in toxicity to normal FetMSC cells but inhibited the growth of lines of “immortal” cervical HeLa cancer cells and human glioblastoma A172. Intact tissues of Sequoia plants and cell cultures initiated from them in vitro are producers of secondary metabolites with high biological activity.
Gut Microbiota Regulates the Homeostasis of Dendritic Epidermal T Cells
Authors: Chung Jinwoo , Lee Joo-Chan , Oh Hanna , Kim Yesung , Lim Suin , Lee Chanu , Shim Yoon-Gyu , Bang Eun-Chong , Baek Jea-Hyun
Published: December 2024

Dendritic epidermal T cells (DETCs) are a γδ T cell subset residing in the skin epidermis. Although they have been known for decades, the fate of DETCs has largely remained enigmatic. Recent studies have highlighted the relationship between the gut microbiome and γδ T cells in various epithelial and non-epithelial tissues, such as the small intestine, lung, liver, gingiva, and testis. While the skin microbiota has been shown to impact skin γδ T cells, a direct relationship between the gut microbiota and DETCs remains unexplored. In this study, we investigated whether DETCs are regulated by the gut microbiota in the steady-state skin epidermis. We examined the occurrence of DETCs in Balb/c mice, which have a skin epidermis barely populated with DETCs, compared to C57BL/6 mice, under different housing conditions. Our findings reveal that local skin inflammation markedly increases DETC numbers in the ear epidermis of Balb/c mice and that DETCs are activated by environmental factors. Furthermore, an investigation of the gut microbiota under different housing conditions revealed distinct microbial compositions and functional profiles. Taken together, these results suggest a strong connection between DETCs and gut microbiota.
Effects of Sequential Antimicrobial Phases on Root Canal Microbiome Dynamics in Two-Visit Treatment of Primary Apical Periodontitis: A Longitudinal Experimental Study
Authors: Kesim Bertan , Tezcan Ülger Seda , Aslan Gönül , Üstün Yakup , Avcı Ayşe Tuğba , Küçük Mustafa Öner
Published: December 2024

Background: Effective management of primary apical periodontitis depends on understanding the dynamic interactions within the root canal microbiome. This study aimed to investigate the effect of sequential antimicrobial phases on the root canal microbiome during a two-visit treatment approach, with a focus on calcium hydroxide medication. Methods: Samples were collected from three teeth across four treatment phases: initial infection (S1), after chemomechanical preparation (S2), after intracanal medication (S3), and after a final flush (S4). DNA was extracted, and the V3–V4 regions of the 16S rRNA gene were sequenced using Illumina MiSeq. Sequencing data were analyzed with QIIME 2, and differentially abundant taxa were identified using linear discriminant analysis effect size (LEfSe). Results: While microbial community composition did not differ significantly between phases, the Firmicutes/Bacteroidetes ratio decreased after the antimicrobial stages. LEfSe analysis revealed higher abundances of Lactobacillales, Arthrobacter, and Veillonella in the untreated (CMP) group. Bifidobacterium longum was relatively more abundant in the intracanal medication (ICM) phase, and Dorea formicigenerans was more abundant in the final-flush (FF) phase. Conclusions: Although calcium hydroxide treatment did not induce statistically significant changes in overall root canal microbial composition, trends such as a reduction in the Firmicutes/Bacteroidetes ratio and a relative increase in Bifidobacterium longum numbers suggest potential ecological shifts. The observed relative increase in Bifidobacterium longum numbers may represent a hypothesis-driven observation reflecting indirect ecological effects rather than direct pH modulation. While visual patterns (e.g., PCA clustering) were observed, they lacked statistical support. Further studies with larger sample sizes are needed to validate these observations and assess the potential role of beneficial bacteria in root canal treatments.
Can Aluminum Affect Social Behavior and Cortisol Plasma Profile in the Neotropical Freshwater Teleost Astyanax lacustris (Teleostei: Characidae)?
Authors: Faria Natália Pires Vieira Morais de , Araújo Bruno Cavalheiro , Kida Bianca Mayumi Silva , Abdalla Raisa Pereira , Brito Diego dos Santos , Moreira Renata Guimarães , Honji Renato Massaaki
Published: December 2024

Aluminum (Al) can cause endocrine disruption in aquatic animals, but assessments of animal social behavior in neotropical teleost fish species with importance for Brazilian aquaculture have still not been addressed so far, which can further complete this ecotoxicological knowledge. In order to evaluate the social behavior and plasma cortisol concentration of fish exposed to Al, we performed a 1 h acute exposure with Astyanax lacustris couples in three different experimental groups: control in neutral pH (CTL/n group), acid pH (pH/ac group), and aluminum in acid pH (Al/ac group; 2.0 mg L−1). An ethogram of social interactions between males and females and swimming activities were performed. Furthermore, the cortisol plasma concentration was measured by enzyme-linked immunosorbent, and the gonadal maturation stage of the animals was evaluated by histology. Adult and mature females in the CTL/n and pH/ac groups were more aggressive and active than mature males, including several attacks on the male. Moreover, males did not present attack behavior in these groups at any time, but did show submission behavior and constant avoidance of female attacks. In the Al/ac, females did not attack males, couple decreased swimming activity, a repetitive movement toward the aquarium surface, and high mucus production were observed, making the water cloudy. Regarding cortisol plasma concentration, males had higher cortisol plasma concentrations than females in the CTL/n and pH/ac groups, which was not observed in the Al/ac group. Therefore, Al in addition to being described in the literature as an endocrine disruptor, it can be considered as behavioral disrupter in A. lacustris in this important freshwater species cultivated in South America.
Long-Term Efficacy of Combined Focused and Radial Extracorporeal Shockwave Therapy for Gluteus Medius Tendon Pathology: A Pilot Study
Authors: Fulceri Federica , Ryskalin Larisa , Morucci Gabriele , Busoni Francesco , Soldani Paola , Gesi Marco
Published: December 2024

Background: Gluteus medius tendinopathy is amongst the most prevalent lower limb tendinopathies and is now recognized as the primary cause of insidious lateral hip pain. Typically affecting middle-aged women, this condition causes disability and reduced quality of life as it negatively impacts most daily life activities. Several studies demonstrate that extracorporeal shockwave therapy is effective in reducing pain and promoting functional recovery in several musculoskeletal disorders including tendinopathies. However, most published data are limited to evaluating focal or radial shockwaves as single interventions. Contrariwise, there is little evidence reporting the use of combined ESWT treatment and outcomes for managing tendon pathologies, and no data are reported on combined ESWT for gluteus medius tendinopathy. Objectives: The aim of this study was to evaluate the clinical outcomes of combined ESWT in gluteus medius tendinopathy. Methods: Medical charts of 11 consecutive patients with gluteal tendinopathy confirmed by ultrasound who underwent a combined ESWT protocol were reviewed. Changes in pain severity and lower limb function were evaluated using the numerical rating scale, the Victorian Institute of Sports Assessment for Gluteal tendinopathy questionnaire, and the Roles and Maudsley score. Clinical outcome measurements were collected at baseline (T0), 2 months after combined ESWT (T1), and at long-term follow-up (T2), at least 10 months post-treatment (mean 26 months). Results: The mean age of the sample was 62.55 ± 3.17 years. A marked prevalence of females was recorded (nine subjects, 81.8%). A significant improvement was observed in all outcome criteria both at short- and long-term follow-up after combined ESWT compared to baseline (p < 0.05). Treatment success rates were 90.9% and 81.8% at T1 and T2, respectively. Conclusions: Combined ESWT is effective and safe for patients with gluteal tendinopathy, with good long-term results in terms of pain relief and improved functional impairment.
Exploring the Effect of Interface Contact States on Brush/Ring Current-Carrying Friction
Authors: Li Chenshi , Zhao Xinze , Lv Yaru , Li Yang , Li Wanting , Yang Wei
Published: December 2024

A carbon brush/collector ring set will have phenomena such as firing and ablation during operation, which is due to the existence of various abnormal contact modes of the brush/ring during operation, thus changing the carbon brush/collector ring interface state. To analyze the effects of different contact modes on the performance of the brush/ring, in this paper, we construct the contact modes of the air gap (loss of contact leads to the existence of a small gap between the two surfaces), direct contact (contact with abrasive particulate media), and surface porosity contact (contact when there is a large pit on the surface of the collector ring due to manufacturing quality defects and abnormal abrasion), and analyze the effects of the various states on the core parameters such as current conduction, ring surface damage, and carbon brush abrasion, which provide a basis for the active suppression of the damage.
Inhomogeneous Nanoscale Conductivity and Friction on Graphite Terraces Explored via Atomic Force Microscopy
Authors: Ozyurt A. Kutay , Baykara Mehmet Z.
Published: December 2024

The interplay of conductivity and friction in layered materials such as graphite is an open area of investigation. Here, we measure local conductivity and friction on terraces of freshly cleaved highly oriented pyrolytic graphite via atomic force microscopy under ambient conditions. The graphite surface is found to exhibit a rich electrical landscape, with different terraces exhibiting different levels of conductivity. A peculiar dependency of conductivity on scan direction is observed on some terraces. The terraces that exhibit this dependency are also found to show enhanced friction values. A hypothesis based on tip asymmetry and the puckering effect is proposed to explain the findings. Our results highlight the non-triviality of the electrical and tribological properties of graphite on the nanoscale, as well as their interplay.
Exploring Metal–Metal Composites: A Study on AA5083 Matrix-Cr Particles Reinforced Composites
Authors: Özkaya Serdar
Published: December 2024

The objective of this study is to develop chromium-reinforced metal–metal composites utilizing an AA5083 aluminum alloy matrix through powder metallurgy while also examining their properties. Samples were produced by incorporating varying quantities of chromium (5%, 10%, and 15% by weight) into the AA5083 matrix. In order to ensure a uniform distribution of chromium particles, the powders were blended in a ball mill and subsequently hot-pressed at 500 °C under 500 MPa for a period of two hours in an argon atmosphere. The resulting samples were subjected to analysis in order to determine the effect of chromium content on the composites, with particular attention being paid to their microstructure, hardness, density, tensile properties, tribological performance and corrosion resistance. The findings demonstrated that an elevated chromium concentration markedly augmented the hardness of the composite, exhibiting a 50% enhancement in the 15 wt.% Cr composite. A 30% reduction in wear loss was observed for the same sample. The A10 sample (10 wt.% Cr) exhibited the greatest corrosion resistance, although this declined in the A15 sample due to increased porosity. Tensile strength increased by up to 10 wt.% Cr before decreasing at 15 wt.% Cr, which was also attributed to porosity. These findings demonstrate that chromium reinforcement enhances the mechanical and tribological performance of AA5083 composites, rendering them suitable for applications requiring high hardness and wear resistance.
Implant Surface Decontamination Methods That Can Impact Implant Wettability
Authors: Romanos Georgios E. , Mistretta Lauren , Newman Allyson , Ohana Danielle , Delgado-Ruiz Rafael A.
Published: December 2024

This review addresses the effects of various decontamination methods on the wettability of titanium and zirconia dental implants. Despite extensive research on surface wettability, there is still a significant gap in understanding how different decontamination techniques impact the inherent wettability of these surfaces. Although the literature presents inconsistent findings on the efficacy of decontamination methods such as lasers, air-polishing, UV light, and chemical treatments, the reviewed studies suggest that decontamination alters in vitro hydrophilicity. Post-decontamination surface chemistry must be carefully considered when selecting optimal surface treatments for implant materials. Further in vitro investigations are essential to determine which approaches best enhance surface wettability, potentially leading to improved implant–tissue interactions in clinical settings.
Fabrication and Coating of Porous Ti6Al4V Structures for Application in PEM Fuel Cell and Electrolyzer Technologies
Authors: Villemur Juan , Romero Carlos , Crego Jose Manuel , Gordo Elena
Published: December 2024

The production of green hydrogen through proton exchange membrane water electrolysis (PEMWE) is a promising technology for industry decarbonization, outperforming alkaline water electrolysis (AWE). However, PEMWE requires significant investment, which can be mitigated through material and design advancements. Components like bipolar porous plates (BPPs) and porous transport films (PTFs) contribute substantially to costs and performance. BPPs necessitate properties like corrosion resistance, electrical conductivity, and mechanical integrity. Titanium, commonly used for BPPs, forms a passivating oxide layer, reducing efficiency. Effective coatings are crucial to address this issue, requiring conductivity and improved corrosion resistance. In this study, porous Ti64 structures were fabricated via powder technology, treating them with thermochemical nitriding. The resulting structures with controlled porosity exhibited enhanced corrosion resistance and electrical conductivity. Analysis through scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), grazing incidence XRD and X-ray photoelectron spectroscopy (XPS) confirmed the effectiveness of the coating, meeting performance requirements for BPPs.
Improving Corrosion Resistance of Rare Earth Zirconates to Calcium–Magnesium–Alumina–Silicate Molten Salt Through High-Entropy Strategy
Authors: Gui Cong , Peng Zi-Jian , Yao Jun-Teng , Wang Shu-Qi , Liu Zhan-Guo , Wang Ya-Ming , Ouyang Jia-Hu
Published: December 2024

The erosion caused by high-temperature calcium–magnesium–alumina–silicate (CMAS) has emerged as a critical impediment to the advancement of thermal barrier coating (TBC). In this study, a series of high-entropy rare earth zirconates, (La0.2Sm0.2Dy0.2Er0.2Gd0.2)2(Zr1−xCex)2O7 (x = 0, 0.2, 0.4, 0.5) were synthesized through a solid-phase reaction, and their corrosion behavior against CMAS was investigated. Our findings demonstrate that numerous rare earth elements impede element diffusion, facilitate the formation of a compact oxide layer, and effectively hinder CMAS infiltration. Furthermore, rare earth elements with larger ionic radii exhibit enhanced solubility in apatite, whereas those with smaller ionic radii are more readily soluble in ZrO2. In general, the utilization of the high-entropy strategy is an effective approach to significantly improving corrosion resistance against CMAS.