bluuebunny/crossref_metadata_2025 huggingface dataset:
Hydrodynamic Modeling of a Large, Shallow Estuary
Authors: Ji Zhen-Gang , Moustafa M. Zaki , Hamrick John
Published: February 2024

Florida Bay, a large and shallow estuary, serves as a vital habitat for a diverse range of marine species and holds significant environmental, commercial, and recreational value. The Florida Bay ecosystem is under extensive stress due to decades of increased nutrient loads. Based on the Environmental Fluid Dynamics Code (EFDC), a hydrodynamic model was developed in this study. The model was calibrated with a comprehensive dataset, including measurements over 7 years from 34 tidal stations, 42 current stations, and 14 temperature and salinity stations. Key findings include the following: (1) the bay exhibits a shift in the tidal regime, transitioning from macro-tidal in the western region to micro-tidal in the central and eastern/northeast regions; (2) local winds and the subtidal variations from the coastal ocean are the primary drivers for the hydrodynamic processes in the eastern and central regions; (3) salinity changes in the bay are primarily controlled by three processes: the net supply of freshwater, the processes that drive mixing within the estuary (e.g., wind, topography, currents), and the exchange of salinity with the coastal ocean. This hydrodynamic model is essential for providing a comprehensive tool to address environmental challenges and sustain the bay’s ecosystem health.
Route Planning Algorithms for Unmanned Surface Vehicles (USVs): A Comprehensive Analysis
Authors: Hashali Shimhanda Daniel , Yang Shaolong , Xiang Xianbo
Published: February 2024

This review paper provides a structured analysis of obstacle avoidance and route planning algorithms for unmanned surface vehicles (USVs) spanning both numerical simulations and real-world applications. Our investigation encompasses the development of USV route planning from the year 2000 to date, classifying it into two main categories: global and local route planning. We emphasize the necessity for future research to embrace a dual approach incorporating both simulation-based assessments and real-world field tests to comprehensively evaluate algorithmic performance across diverse scenarios. Such evaluation systems offer valuable insights into the reliability, endurance, and adaptability of these methodologies, ultimately guiding the development of algorithms tailored to specific applications and evolving demands. Furthermore, we identify the challenges to determining optimal collision avoidance methods and recognize the effectiveness of hybrid techniques in various contexts. Remarkably, artificial potential field, reinforcement learning, and fuzzy logic algorithms emerge as standout contenders for real-world applications as consistently evaluated in simulated environments. The innovation of this paper lies in its comprehensive analysis and critical evaluation of USV route planning algorithms validated in real-world scenarios. By examining algorithms across different time periods, the paper provides valuable insights into the evolution, trends, strengths, and weaknesses of USV route planning technologies. Readers will benefit from a deep understanding of the advancements made in USV route planning. This analysis serves as a road map for researchers and practitioners by furnishing insights to advance USV route planning and collision avoidance techniques.
Suppression of Negative Sequence Current on HVDC Modular Multilevel Converters in Offshore Wind Power
Authors: Xu Xiaoning , Wang Di , Zhou Xuesong , Tao Long
Published: February 2024

The High Voltage Direct Current (HVDC) transmission technology employing modular multilevel converters (MMCs) can effectively enhance the transmission efficiency and stability of offshore wind farms, thereby aiding the promotion of large−scale utilization of new energy. This holds significant importance for achieving the dual carbon goals. Aiming at the problem of negative sequence current circulation in MMC−HVDC transmission systems, a circulation suppression strategy based on augmented order decoupling linear active disturbance rejection control (LADRC) is proposed in this paper. By introducing new state variables into the traditional ADRC structure, the actual output deviation signal and observation gain signal from the disturbance observation value of the system are used. It can not only realize the decoupling control of disturbance and tracking terms but also enhance the disturbance immunity, robustness and rapidity of the controller. Finally, an 18−level MMC system model is built based on Matlab (9.12.0.1884302 (R2022a)) & Simulink (R2022a), and the circulation suppression effects of stable operation and voltage sudden change are simulated and compared, which verifies the suppression effect of the improved control strategy on negative sequence current circulation, which lays a theoretical and application foundation for the sustainable development of the offshore wind power industry.
Knowledge and Use of the 2011 Freedom of Information Act among Journalists in Nigeria
Authors: Eze Ogemdi Uchenna
Published: February 2024

This study examined the knowledge and use of the 2011 Freedom of Information Act among journalists in Nigeria. The hierarchy of influences model provided the theoretical lens, which guided the study. Through a survey of 313 Nigerian journalists, the study found that there was a high level of knowledge of the Act among Nigerian journalists. Nigerian journalists perceived the Act as a useful journalistic tool, and they often used it for such purposes as confirming facts, writing controversial topics and to gain insight into the inner working of government. The study showed that, in the use of the Act in journalistic duties, Nigerian journalists were confronted with the challenges of non-integration of the provisions of the Act in the operations of government agencies, adversarial disposition of government institutions towards journalists and the pervasive culture of secrecy. The study established that knowledge of the Act positively correlated with its use. The implications of the findings were discussed.
Operational Risk Management in Banks: A Bibliometric Analysis and Opportunities for Future Research
Authors: Jadwani Barkha , Parkhi Shilpa , Mitra Pradip Kumar
Published: February 2024

The last few years have witnessed tremendous challenges in the management of operational risks faced by banks and the emergence of newer risks. The working models for bank staff are now different; additionally, there has been a massive increase in the digitization level. All these aspects make operational risk management in banks an attractive field of study. There is a need to perform systematic bibliometric analysis in this research area, providing the various trends and highlighting areas for further research analysis. This research paper has examined the various aspects of operational risk management in Banks by performing a thorough bibliometric analysis of 676 articles extracted from two data databases, i.e., Scopus and Web of Science, from 2010 until March 2023. These were analyzed using the tools Biblioshiny and VOSviewer. Various bibliometric techniques like analysis of trends, citations, contributing authors, keywords, and bibliographic coupling have been performed. This research paper has significant theoretical and practical implications which can assist future researchers. Operational risks are ever-dynamic, and five themes, i.e., climate risk, information security risks, geopolitical risks, third-party risks and compliance risks, have been identified in this research paper as key focus areas for conducting research in the future. The findings of this study and suggestions for future research will be useful to academicians, policymakers, and operational risk management professionals for identifying potential areas of collaboration in the future to strengthen the operational risk management framework.
How Australia Has Been Affected by US Monetary and Fiscal Policies: 1960 to 2022
Authors: Leightner Jonathan
Published: February 2024

This paper uses Reiterative Truncated Projected Least Squares to estimate the effects of US monetary and fiscal policy on Australia using quarterly data between 1960 and 2022. When Australia had a fixed exchange rate (1960–1983), both US fiscal and monetary policies were positively correlated with Australia’s GDP, which fits the predictions of a small-country IS/LM/BP model with relatively immobile capital. When Australia had a flexible exchange rate (1984–2022), US fiscal policy was positively correlated with Australia’s GDP, but US monetary policy was negatively correlated with Australia’s GDP, which fits the predictions of a large-country IS/LM/BP model.
Quantifying Spatiotemporal Characteristics and Identifying Influential Factors of Ecosystem Fragmentation in Karst Landscapes: A Comprehensive Analytical Framework
Authors: Wu Xiaopiao , Zhou Zhongfa , Zhu Meng , Wang Jiale , Liu Rongping , Zheng Jiajia , Wan Jiaxue
Published: February 2024

Guanling-Zhenfeng County, a microcosm of the ecologically fragile karst area in southwest China, experiences rapid population growth and urban expansion which intensifies land use transformation and ecological landscape fragmentation. Exploring the spatiotemporal characteristics of landscape fragmentation and its causes in Guanling-Zhenfeng County is of great significance in maintaining the stability of the ecosystem and ecological protection in karst areas. In this study, a comprehensive landscape fragmentation index (FI), geographic probe, multi-scale geographically weighted regression (MGWR), and PLUS model were used to quantitatively explore the spatiotemporal characteristic heterogeneity, causes, and future scenario projections of landscape fragmentation in Guanling-Zhenfeng County from 2000 to 2020. The results showed that: (1) the distribution of each landscape index was characterized by obvious spatial differentiation. Among them, the spatial distribution trends of patch density (PD) and largest patch index (LPI) were opposite and the distribution trends of Shannon diversity index (SHDI) and Shannon evenness index (SHEI) were similar. There were fewer heterogeneous patches in the study area from 2000 to 2020, and the landscape shape was more regular and less fragmented. (2) The overall landscape fragmentation in Guanling-Zhenfeng County from 2000 to 2020 was dominated by moderate fragmentation, with the smallest percentage of extreme fragmentation, and heavy fragmentation was mainly distributed in the north-central part of the study area. (3) Natural and social factors jointly affect the landscape fragmentation in Guanling-Zhenfeng County, and there is a significant interactive enhancement effect among the factors, with population density being the most important influence factor. In addition, the effects of the factors on landscape fragmentation showed significant spatial non-stationarity. (4) The characteristics of landscape fragmentation changes in Guanling-Zhenfeng County under different scenarios varied significantly, with the largest percentage of increase in heavy landscape fragmentation under the business-as-usual scenario (BAU), the next under the land use planning scenario (LUP), and the smallest under the ecological protection scenario (ESP).
Discrimination of Degrees of Foreign Accent across Different Speakers
Authors: Pérez-Ramón Rubén
Published: February 2024

Second-language learners often encounter communication challenges due to a foreign accent (FA) in their speech, influenced by their native language (L1). This FA can affect rhythm, intonation, stress, and the segmental domain, which consists of individual language sounds. This study looks into the segmental FA aspect, exploring listeners’ perceptions when Spanish interacts with English. Utilizing the SIAEW corpus, which replaces segments of English words with anticipated Spanish-accented realizations, we assess the ability of non-native listeners to discriminate degrees of accent across male and female voices. This research aims to determine the impact of voice consistency on detecting accentedness variations, studying participants from Japanese and Spanish. Results show that, while listeners are generally able to discriminate degrees of foreign accent across speakers, some segmental transformations convey a more clear distinction depending on the phonological representations of the native and accented realisations on the listener’s system. Another finding is that listeners tend to better discriminate degrees of accent when words are more native-like sounding.
Structural and Dynamic Analyses of Pathogenic Variants in PIK3R1 Reveal a Shared Mechanism Associated among Cancer, Undergrowth, and Overgrowth Syndromes
Authors: Dsouza Nikita R. , Cottrell Catherine E. , Davies Olivia M. T. , Tollefson Megha M. , Frieden Ilona J. , Basel Donald , Urrutia Raul , Drolet Beth A. , Zimmermann Michael T.
Published: February 2024

The PI3K enzymes modify phospholipids to regulate cell growth and differentiation. Somatic variants in PI3K are recurrent in cancer and drive a proliferative phenotype. Somatic mosaicism of PIK3R1 and PIK3CA are associated with vascular anomalies and overgrowth syndromes. Germline PIK3R1 variants are associated with varying phenotypes, including immunodeficiency or facial dysmorphism with growth delay, lipoatrophy, and insulin resistance associated with SHORT syndrome. There has been limited study of the molecular mechanism to unify our understanding of how variants in PIK3R1 drive both undergrowth and overgrowth phenotypes. Thus, we compiled genomic variants from cancer and rare vascular anomalies and sought to interpret their effects using an unbiased physics-based simulation approach for the protein complex. We applied molecular dynamics simulations to mechanistically understand how genetic variants affect PIK3R1 and its interactions with PIK3CA. Notably, iSH2 genetic variants associated with undergrowth destabilize molecular interactions with the PIK3CA receptor binding domain in simulations, which is expected to decrease activity. On the other hand, overgrowth and cancer variants lead to loss of inhibitory interactions in simulations, which is expected to increase activity. We find that all disease variants display dysfunctions on either structural characteristics or intermolecular interaction energy. Thus, this comprehensive characterization of novel mosaic somatic variants associated with two opposing phenotypes has mechanistic importance and biomedical relevance and may aid in future therapeutic developments.
Adsorption Behavior of NO and NO2 on Two-Dimensional As, Sb, and Bi Materials: First-Principles Insights
Authors: Zhang Yuting , Chen Xi , Fang Dan , Yan Hao , Wang Dengkui , Wang Xiaohua , Li Jinhua , Zhai Yingjiao , Chu Xueying , Wang Dongbo , Zhao Hongbin , Fang Xuan
Published: February 2024

To address the most significant environmental challenges, the quest for high-performance gas sensing materials is crucial. Among numerous two-dimensional materials, this study investigates the gas-sensitive capabilities of monolayer As, Sb, and Bi materials. To compare the gas detection abilities of these three materials, we employ first-principles calculations to comprehensively study the adsorption behavior of NO and NO2 gas molecules on the material surfaces. The results indicate that monolayer Bi material exhibits reasonable adsorption distances, substantial adsorption energies, and significant charge transfer for both NO and NO2 gases. Therefore, among the materials studied, it demonstrates the best gas detection capability. Furthermore, monolayer As and Sb materials exhibit remarkably high capacities for adsorbing NO and NO2 gas molecules, firmly interacting with the gas molecules. Gas adsorption induces changes in the material’s work function, suggesting the potential application of these two materials as catalysts.
The Influence of Reflowing Process on Electrodeposited Sn-Cu-Ni Lead-Free Solder Alloy
Authors: State (Rosoiu) Sabrina Patricia , Costovici Stefania , Enachescu Marius , Visan Teodor , Anicai Liana
Published: February 2024

Sn-Cu-Ni lead-free solder alloy electrodeposited on copper substrate from a deep eutectic solvent (DES)-based electrolyte under direct current (DC) and pulsed current (PC) was subjected to a reflowing process at the industrial company MIBATRON S.R.L. (Otopeni, Romania). The alteration of the alloy’s composition and anti-corrosive properties upon exposure to the reflow process were investigated via Scanning Electron Microscopy (SEM-EDX), X-ray diffraction (XRD), linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Corrosion studies conducted in sodium chloride solution revealed that the system obtained under the DC plating mode (Sn-Cu-Ni-DC) exhibited enhanced anti-corrosive properties compared to the system obtained under PC (Sn-Cu-Ni-PC) after reflowing. However, prior to reflowing, the opposite effect was observed, with Sn-Cu-Ni-PC showing improved anti-corrosive properties. These changes in anti-corrosive behavior were attributed to the modification of the alloy’s composition during the reflowing process.
4.6-Bit Quantization for Fast and Accurate Neural Network Inference on CPUs
Authors: Trusov Anton , Limonova Elena , Nikolaev Dmitry , Arlazarov Vladimir V.
Published: February 2024

Quantization is a widespread method for reducing the inference time of neural networks on mobile Central Processing Units (CPUs). Eight-bit quantized networks demonstrate similarly high quality as full precision models and perfectly fit the hardware architecture with one-byte coefficients and thirty-two-bit dot product accumulators. Lower precision quantizations usually suffer from noticeable quality loss and require specific computational algorithms to outperform eight-bit quantization. In this paper, we propose a novel 4.6-bit quantization scheme that allows for more efficient use of CPU resources. This scheme has more quantization bins than four-bit quantization and is more accurate while preserving the computational efficiency of the later (it runs only 4% slower). Our multiplication uses a combination of 16- and 32-bit accumulators and avoids multiplication depth limitation, which the previous 4-bit multiplication algorithm had. The experiments with different convolutional neural networks on CIFAR-10 and ImageNet datasets show that 4.6-bit quantized networks are 1.5–1.6 times faster than eight-bit networks on the ARMv8 CPU. Regarding the quality, the results of the 4.6-bit quantized network are close to the mean of four-bit and eight-bit networks of the same architecture. Therefore, 4.6-bit quantization may serve as an intermediate solution between fast and inaccurate low-bit network quantizations and accurate but relatively slow eight-bit ones.
Simulation-Based Analysis for Verifying New Certification Standards of Smart LED Streetlight Systems
Authors: Cho Seung-Wan , Seo Kyung-Min , Yun Jung-Min , Kang Bong-Gu
Published: February 2024

The need for certification standards for new convergence products, such as a smart LED streetlight system, has been identified as a critical issue. This study proposes simulation modeling for smart LED streetlight systems and suggests three certification standards: the minimum time to initiate dimming-up, the duration of the dimming-up period, and the number of concurrently controlled streetlights. We utilized Relux to model streetlights and roads in terms of luminance levels, and used analytical formulas to compute the braking distances of oncoming vehicles. The two models were integrated into a smart LED streetlight system model using Simio. Simulation experiments were conducted with two objectives: to provide certification standards, and to apply and verify them in real-world cases. We experimented with 630 scenarios, modeling various dynamic situations involving roads and vehicles, and applied the model to two actual roads in the Republic of Korea to test its validity. The model was subsequently applied to roads for which traffic-volume data were available, to determine potential energy savings. The proposed simulation method can be applied to a smart LED streetlight system and to new products that lack certification standards. Furthermore, the proposed certification standards offer alternative approaches to operating streetlight systems more efficiently.
Cloning and Characterization of a Novel N-Acetyl-D-galactosamine-4-O-sulfate Sulfatase, SulA1, from a Marine Arthrobacter Strain
Authors: Christensen Monica Daugbjerg , Allahgholi Leila , Linares-Pastén Javier A. , Friðjónsson Ólafur , Guðmundsson Hörður , Kale Varsha , Sardari Roya R. R. , Hreggviðsson Guðmundur Ó. , Karlsson Eva Nordberg
Published: February 2024

Sulfation is gaining increased interest due to the role of sulfate in the bioactivity of many polysaccharides of marine origin. Hence, sulfatases, enzymes that control the degree of sulfation, are being more extensively researched. In this work, a novel sulfatase (SulA1) encoded by the gene sulA1 was characterized. The sulA1-gene is located upstream of a chondroitin lyase encoding gene in the genome of the marine Arthrobacter strain (MAT3885). The sulfatase was produced in Escherichia coli. Based on the primary sequence, the enzyme is classified under sulfatase family 1 and the two catalytic residues typical of the sulfatase 1 family—Cys57 (post-translationally modified to formyl glycine for function) and His190—were conserved. The enzyme showed increased activity, but not improved stability, in the presence of Ca2+, and conserved residues for Ca2+ binding were identified (Asp17, Asp18, Asp277, and Asn278) in a structural model of the enzyme. The temperature and pH activity profiles (screened using p-nitrocatechol sulfate) were narrow, with an activity optimum at 40–50 °C and a pH optimum at pH 5.5. The Tm was significantly higher (67 °C) than the activity optimum. Desulfation activity was not detected on polymeric substrates, but was found on GalNAc4S, which is a sulfated monomer in the repeated disaccharide unit (GlcA–GalNAc4S) of, e.g., chondroitin sulfate A. The position of the sulA1 gene upstream of a chondroitin lyase gene and combined with the activity on GalNAc4S suggests that there is an involvement of the enzyme in the chondroitin-degrading cascade reaction, which specifically removes sulfate from monomeric GalNAc4S from chondroitin sulfate degradation products.
What Is the Added Value of Carotid CEUS in the Characterization of Atherosclerotic Plaque?
Authors: Lioznovs Andrejs , Radzina Maija , Saule Laura , Grinbergs Peteris Einars , Lacis Aigars
Published: February 2024

Background and Objectives: Unstable atherosclerotic plaque in the arteries is one of the main risk factors for cerebral ischemia. Duplex ultrasound is a frequently used diagnostic method, but it has some limitations for microvascularization and neovascularization evaluation. The aim of this review was to evaluate the role of the new multiparametric US method—contrast-enhanced ultrasound (CEUS)—in atherosclerotic plaque instability verification. Materials and Methods: Original studies, reviews, and meta-analyses were included in this article. A total of 53 studies were retrieved; 29 were included in this study. Results: Carotid artery CEUS as a part of the multiparametric ultrasound method shows promising results and provides additional characteristics of soft- and high-risk atherosclerotic plaques; it can be advised in clinical practice for patients with carotid artery soft- and high-risk plaques. However, there are some limitations, such as extensive calcinosis with important acoustic shadows in carotid atherosclerotic plaque neovascularization diagnostics by CEUS. The added value of CEUS in the characterization of atherosclerotic plaque is that it indicates regions with high neovascularization and visualizes ulcerations on plaque surfaces, suggestive of increased instability risk.
Optimizing Air Scouring Energy for Sustainable Membrane Bioreactor Operation by Characterizing the Combination of Factors Leading to Threshold Limiting Conditions
Authors: Jun Changyoon , Aghasadeghi Kimia , Daigger Glen T.
Published: February 2024

Key operating variables to predict the necessary scour air flowrate in full-scale Membrane Bioreactor (MBR) systems are identified, aiming to optimize energy consumption while avoiding the limiting condition (i.e., rapid increasing total resistance). The resulting metric, referred to here as the K value, was derived by balancing hydrodynamic conditions between the particle deposit rate imposed by permeate flux normalized by fouling condition and its removal by shear stress induced from air scouring. The metric includes air scouring flow, permeate flow, Mixed Liquor Suspended Solids (MLSS) concentration, Mixed Liquor (ML) viscosity, membrane packing density, and total resistance. Long-term (year-long) data from two full-scale MBR plants were analyzed. The value of K corresponding to limiting operational operation and referred to as the limiting K value, KLim, is estimated by detecting the occurrence of threshold limiting flux from the data stream and calculating the resulting value for K. Then, using KLim, the minimum required specific air demand per permeate (SADp,Crit) is calculated, indicating a potential reduction of over half the air scouring energy in typical operational conditions. The results from this data driven analysis suggest the feasibility of employing KLim to predict the adequate scour air flowrate in terms of dynamically varying operational conditions. This approach will lead to the development of energy-efficient algorithms, significantly reducing scour air energy consumption in the full-scale MBR system.
The Design of a Fiber-Coupling Micro-Lens Array for an M × N Wavelength-Selective Switch
Authors: Hao Jiaqi , Gao Yunshu , Dong Chengcheng , Meng Zeyuan , Chen Genxiang
Published: February 2024

The M × N port wavelength-selective switch (WSS) is a crucial device used for Reconfigurable Optical Add/Drop Multiplexors and optical switching nodes in optical communication systems. The primary function of an M × N port WSS is to simultaneously transmit and switch multiple input optical signals from input fiber ports to output fiber ports through spatial light coupling. The port array module in a WSS that is responsible for coupling the spatial beam with the fiber determines the important parameters of the M × N port WSS, such as the number of input/output ports and insertion loss. In this paper, VirtualLab Fusion software 2023.1 (Build 1.558), as a powerful physical optics simulation tool, is used to design and optimize a silicon micro-lens array that can achieve the high-precision coupling of a fiber array with a pitch of 1143 μm. Finally, the designed micro-lens is manufactured and experimentally demonstrates its good beam focusing ability with a 3 dB insertion loss. The designed micro-lens array coupling system, which delivers 28 focused spots of approximately 1mm in size (the beam has a 1/e2 diameter) after transmitting a distance of around 300 mm, effectively extends the number of WSS ports. This design method of the micro-lens array significantly amplifies the port count of the M × N port wavelength-selective switch, effectively expanding it to encompass an impressive 28 × 28 ports.
Characterization of Shrink Film Properties for Rapid Microfluidics Lab-on-Chip Fabrication
Authors: Kong Tian Fook , Ang Alger Wai Jiat , Marcos Marcos
Published: February 2024

Shrink film is a thin sheet of polystyrene plastic that shrinks to 25–40% of its original size when heated. This study investigated the shrinkage factor of the film at different temperatures and baking times to determine the optimal fabrication recipe for shrink film microfluidic device production. Additionally, this study characterized the properties of shrink film, including minimum possible feature size and cross-section geometries, using manual engraving and the CAMEO 4 automated cutting machine. The optimal shrinkage factor ranged from 1.7 to 2.9 at 150 °C and a baking time of 4 min, producing the ideal size for microfluidic device fabrication. The X- and Y-axes shrank ~2.5 times, while Z-axis thickened by a factor of ~5.8 times. This study achieved a minimum feature size of 200 microns, limited by the collapsing of channel sidewalls when shrunk, leading to blockages in the microchannel. These findings demonstrate the feasibility and versatility of using shrink film as a cost-effective and efficient material for the rapid fabrication of microfluidic devices. The potential applications of this material in various fields such as the medical and biomedical industries, bacteria and algae culture and enumeration are noteworthy.
Effect of Metal Oxide Semiconductor Field-Effect Transistor Output Parasitic Capacitance on Efficiency in Full-Bridge LLC DC/DC Converters
Authors: Chen Ming-Hung , Hsieh Chia-Wen
Published: February 2024

This study analyzed the efficiency impact of a MOSFET output parasitic capacitance (Coss) on a full-bridge LLC DC/DC converter. The core of the converter was the control chip for a half-bridge LLC DC/DC converter, and the output signal of the chip controlled the first-arm power transistors of the primary side of the converter. The coupling transformer reversed the output signal to control the primary side of the second arm of the power transistor. The full-bridge converter comprises a half-bridge control chip that converts the high-voltage DC power supply to a low-voltage DC power supply, which is then synchronously rectified and supplied to the load. The primary side of the power transistor achieves a zero-voltage switching (ZVS) state through the resonance of the LLC converter. This design gives the converter high power density and a simple structure. Furthermore, to determine the appropriate output parasitic capacitance for improving converter efficiency, this study analyzed the effect of the output parasitic capacitance on the switching loss and conduction loss of the power transistor on the basis of the output parasitic capacitance of the primary-side power transistor. A 1200 W converter prototype was fabricated in this study, and when the output was 300 W, efficiency increased from 92.603% to 93.462%, a 0.859% increase. The empirical results verified the feasibility of the proposed theory.
Denitrification Characteristics of the Low-Temperature Tolerant Denitrification Strain Achromobacter spiritinus HS2 and Its Application
Authors: Gao Ya-Juan , Zhang Ting , Hu Ling-Kang , Liu Shi-Yuan , Li Chen-Chen , Jin Yong-Sheng , Liu Hong-Bin
Published: February 2024

The low-temperature environment significantly inhibits the growth and metabolism of denitrifying bacteria, leading to an excessive concentration of ammonia nitrogen and total nitrogen in sewage treatment plants during the cold season. In this study, an efficient denitrifying strain of heterotrophic nitrification–aerobic denitrification (HN–AD) bacteria named HS2 was isolated and screened from industrial sewage of a chemical factory in Inner Mongolia at 8 °C. The strain was confirmed to be Achromobacter spiritinus, a colorless rod-shaped bacterium. When cultured with sodium succinate as the carbon source, a carbon-to-nitrogen ratio of 20–30, a shaking rate of 150–180 r/min, and an initial pH of 6–10, the strain HS2 exhibited excellent nitrogen removal at 8 °C. Through the results of whole-genome sequencing, gene amplification, and gas product detection, the strain HS2 was determined to possess key enzyme genes in both nitrification and denitrification pathways, suggesting a HN–AD pathway of NH4+-N → NH2OH → NO2−N → NO → N2O → N2. At 8 °C, the strain HS2 could completely remove ammonia nitrogen from industrial sewage with an initial concentration of 127.23 mg/L. Microbial species diversity analysis of the final sewage confirmed Achromobacter sp. as the dominant genus, which indicated that the low-temperature denitrifying strain HS2 plays an important role in nitrogen removal in actual low-temperature sewage.
Evaluation of Cellular Responses of Heterotrophic Escherichia coli Cultured with Autotrophic Chlamydomonas reinhardtii as a Nutrient Source by Analyses Based on Microbiology and Transcriptome
Authors: Nakanishi Akihito , Omino Natsumi , Nakamura Tomoyo , Goto Saki , Matsumoto Riri , Yomogita Misaki , Narisawa Naoki , Kimijima Manami , Iritani Kohei
Published: February 2024

Heterotrophic microorganism Escherichia coli LS5218 was cultured with flesh green alga Chlamydomonas reinhardtii C-9: NIES-2235 as a nutrient supplier. In order to evaluate the cell response of Escherichia coli with Chlamydomonas reinhardtii, Escherichia coli was evaluated with microbial methods and comprehensive gene transcriptional analyses. Escherichia coli with Chlamydomonas reinhardtii showed a specific growth rate (µmax) of 1.04 ± 0.27, which was similar to that for cells growing in Luria–Bertani medium (µmax = 1.20 ± 0.40 h−1). Furthermore, comparing the cellular responses of Escherichia coli in a green-algae-containing medium with those in the Luria–Bertani medium, transcriptomic analysis showed that Escherichia coli upregulated gene transcription levels related to glycolysis, 5-phospho-d-ribosyl-1-diphosphate, and lipid synthesis; on the other hand, it decreased the levels related to lipid degradation. In particular, the transcription levels were increased by 103.7 times on pgm (p * < 0.05 (p = 0.015)) in glycolysis, and decreased by 0.247 times on fadE (p * < 0.05 (p = 0.041)) in lipolysis. These genes are unique and could regulate the direction of metabolism; these responses possibly indicate carbon source assimilation as a cellular response in Escherichia coli. This paper is the first report to clarify that Escherichia coli, a substance-producing strain, directly uses Chlamydomonas reinhardtii as a nutrient supplier by evaluation of the cellular responses analyzed with microbial methods and transcriptome analysis.
Effect of Temperature on Carbapenemase-Encoding Plasmid Transfer in Klebsiella pneumoniae
Authors: Yang Ji Woo , Nam Ji-Hyun , Lee Kwang Jun , Yoo Jung Sik
Published: February 2024

Bacteria causing human infections can develop antibiotic resistance due to various factors. Temperature affects bacterial growth and gene transfer; however, studies exploring the association between the changes in local temperature and antibiotic resistance are limited. Here, we investigated the effects of local temperatures on the distribution of antibiotic resistance and transmission of carbapenemase-producing Enterobacterales using the data on Klebsiella pneumoniae from sentinel hospitals in eight regions included in the Korea Global Antimicrobial Resistance Surveillance System between 2017 and 2021. The resistance rates to most antibiotics, including carbapenems, varied significantly according to local temperature (p < 0.047), except for aminoglycosides. Conjugation experiments at various temperatures for strains encoding the carbapenemase gene on a plasmid revealed significant variation in the optimal conjugation temperatures for plasmids carrying blaKPC and blaNDM genes. The optimal conjugation temperatures demonstrating the highest stability for blaKPC- and blaNDM-carrying plasmids were 25 °C (p = 0.030) and 30 °C (p = 0.007), respectively. The stability of blaKPC-IncF was higher at 25 °C than that at 30 °C (p = 0.032) or 37 °C (p = 0.047), while blaKPC-IncX3 exhibited the lowest stability at 37 °C (p = 0.047). blaNDM-IncX3 was more stable at 30 °C than at 37 °C (p = 0.049). These findings suggest that the optimal temperature for carbapenemase gene transmission varied between 25 °C and 30 °C, indicating that warmer seasons promote the transfer of more antibiotic resistance-related genes and highlighting the importance of local temperature in the spread and transmission of plasmids carrying carbapenemases.
Zircon U-Pb and Whole-Rock Geochemistry of the Aolunhua Mo-Associated Granitoid Intrusion, Inner Mongolia, NE China
Authors: Li Hao , Li Xuguang , Xin Jiang , Yang Yongqiang
Published: February 2024

The Aolunhua Mo deposit is a typical porphyry deposit, which is located in the middle southern section of the Da Hinggan Range metallogenic belt. Here, we report LA-ICP-MS zircon U-Pb age data from the Mo-associated granitoid, together with the element geochemistry of the zircons, discussing the source material of the ore-forming rock of the deposit. The zircon data constrain the crystallization age of the granite porphyry as 135.0 ± 1.0 Ma, correlating it with the widespread Yanshanian intermediate–felsic magmatic activity. The Th/U ratio of the zircon is greater than 0.1, with a significant positive Ce anomaly (Ce* = 1.72–188.71) and a negative Eu anomaly (Eu* = 0.05–0.57). The zircons show depleted LREE and enriched HREE patterns, as well as low La and Pr contents, suggesting crystallization from crust-derived magmas. Based on the geology of the ore deposit and the age data, in combination with the regional geodynamic evolution, we infer that the Aolunhua Mo deposit was formed near the peak stage of Sn poly-metallic metallogenesis in the Da Hinggan Range region at around 140 Ma, associated with a tectonic setting, characterized by the transition from compression to extension. Based on a comparison with the newly found Mo deposits along the banks of the Xilamulun River, we propose that the Tianshan–Linxi is an important Mo-metallogenic belt. It also suggests an increased likelihood for the occurrence of Mo along the north bank of the Xilamulun River.
Up- and Down-Regulation of Enzyme Activity in Aggregates with Gold-Covered Magnetic Nanoparticles Triggered by Low-Frequency Magnetic Field
Authors: Veselov Maxim M. , Efremova Maria V. , Prusov Andrey N. , Klyachko Natalia L.
Published: February 2024

The modern global trend toward sustainable processes that meet the requirements of “green chemistry” provides new opportunities for the broad application of highly active, selective, and specific enzymatic reactions. However, the effective application of enzymes in industrial processes requires the development of systems for the remote regulation of their activity triggered by external physical stimuli, one of which is a low-frequency magnetic field (LFMF). Magnetic nanoparticles (MNPs) transform the energy of an LFMF into mechanical forces and deformations applied to enzyme molecules on the surfaces of MNPs. Here, we demonstrate the up- and down-regulation of two biotechnologically important enzymes, yeast alcohol dehydrogenase (YADH) and soybean formate dehydrogenase (FDH), in aggregates with gold-covered magnetic nanoparticles (GCMNPs) triggered by an LFMF. Two types of aggregates, “dimeric” (with the enzyme attached to several GCMNPs simultaneously), with YADH or FDH, and “monomeric” (the enzyme attached to only one GCMNP), with FDH, were synthesized. Depending on the aggregate type (“dimeric” or “monomeric”), LFMF treatment led to a decrease (down-regulation) or an increase (up-regulation) in enzyme activity. For “dimeric” aggregates, we observed 67 ± 9% and 47 ± 7% decreases in enzyme activity under LFMF exposure for YADH and FDH, respectively. Moreover, in the case of YADH, varying the enzyme or the cross-linking agent concentration led to different magnitudes of the LFMF effect, which was more significant at lower enzyme and higher cross-linking agent concentrations. Different responses to LFMF exposure depending on cofactor presence were also demonstrated. This effect might result from a varying cofactor binding efficiency to enzymes. For the “monomeric” aggregates with FDH, the LFMF treatment caused a significant increase in enzyme activity; the magnitude of this effect depended on the cofactor type: we observed up to 40% enzyme up-regulation in the case of NADP+, while almost no effect was observed in the case of NAD+.
Obesity and Nutrigenetics Testing: New Insights
Authors: Duarte Mychelle Kytchia Rodrigues Nunes , Leite-Lais Lúcia , Agnez-Lima Lucymara Fassarella , Maciel Bruna Leal Lima , Morais Ana Heloneida de Araújo
Published: February 2024

Background: Obesity results from interactions between environmental factors, lifestyle, and genetics. In this scenario, nutritional genomics and nutrigenetic tests stand out, with the promise of helping patients avoid or treat obesity. This narrative review investigates whether nutrigenetic tests may help to prevent or treat obesity. Scientific studies in PubMed Science Direct were reviewed, focusing on using nutrigenetic tests in obesity. The work showed that few studies address the use of tools in obesity. However, most of the studies listed reported their beneficial effects in weight loss. Ethical conflicts were also discussed, as in most countries, there are no regulations to standardize these tools, and there needs to be more scientific knowledge for health professionals who interpret them. International Societies, such as the Academy of Nutrition and Dietetics and the Brazilian Association for the Study of Obesity and Metabolic Syndrome, do not recommend nutrigenetic tests to prevent or treat obesity, especially in isolation. Advancing nutrigenetics depends on strengthening three pillars: regulation between countries, scientific evidence with clinical validity, and professional training.
Association between Low Energy Availability (LEA) and Impaired Sleep Quality in Young Rugby Players
Authors: Saidi Oussama , Souabni Maher , Del Sordo Giovanna C. , Maviel Clément , Peyrel Paul , Maso Freddy , Vercruyssen Fabrice , Duché Pascale
Published: February 2024

Low energy availability (LEA) has been associated with several physiological consequences, but its impact on sleep has not been sufficiently investigated, especially in the context of young athletes. This study examined the potential association between energy availability (EA) status and objective sleep quality in 42 male rugby players (mean age: 16.2 ± 0.8 years) during a 7-day follow-up with fixed sleep schedules in the midst of an intensive training phase. Participants’ energy intake was weighed and recorded. Exercise expenditure was estimated using accelerometry. Portable polysomnography devices captured sleep on the last night of the follow-up. Mean EA was 29.3 ± 9.14 kcal·kg FFM−1·day−1, with 47.6% of athletes presenting LEA, 35.7% Reduced Energy Availability (REA), and 16.7% Optimal Energy Availability (OEA). Lower sleep efficiency (SE) and N3 stage proportion, along with higher wake after sleep onset (WASO), were found in participants with LEA compared to those with OEA (p = 0.04, p = 0.03 and p = 0.005, respectively, with large effect sizes). Segmented regression models of the EA-sleep outcomes (SE, sleep onset latency [SOL]), WASO and N3) relationships displayed two separate linear regions and produced a best fit with a breakpoint between 21–33 kcal·kg FFM−1·day−1. Below these thresholds, sleep quality declines considerably. It is imperative for athletic administrators, nutritionists, and coaches to conscientiously consider the potential impact of LEA on young athletes’ sleep, especially during periods of heavy training.
Effect of Creatine Supplementation on Body Composition and Malnutrition-Inflammation Score in Hemodialysis Patients: An Exploratory 1-Year, Balanced, Double-Blind Design
Authors: Marini Ana Clara B. , Schincaglia Raquel M. , Candow Darren G. , Pimentel Gustavo D.
Published: February 2024

Hemodialysis has a detrimental effect on fat-free mass (FFM) and muscle strength over time. Thus, we aimed to evaluate the effect of creatine supplementation on the body composition and Malnutrition-Inflammation Score (MIS) in patients with chronic kidney disease (CKD) undergoing hemodialysis. An exploratory 1-year balanced, placebo-controlled, and double-blind design was conducted with hemodialysis patients (≥18 years). The creatine group (CG) received 5 g of creatine monohydrate and 5 g of maltodextrin per day and the placebo group (PG) received 10 g of maltodextrin per day. MIS and body composition were analyzed at three time points: pre, intermediate (after 6 months), and post (after 12 months). After 6 months, 60% of patients on creatine experienced an increase in FFM compared to a 36.8% increase for those on placebo. Moreover, 65% of patients on creatine increased their skeletal muscle mass index (SMMI) compared to only 15.8% for those on placebo. Creatine increased intracellular water (ICW) in 60% of patients. MIS did not change after the intervention. In the CG, there was an increase in body weight (p = 0.018), FFM (p = 0.010), SMMI (p = 0.022). CG also increased total body water (pre 35.4 L, post 36.1 L; p = 0.008), mainly due to ICW (pre 20.2 L, intermediate 20.7 L, post 21.0 L; p = 0.016). Long-term creatine supplementation in hemodialysis patients did not attenuate the MIS, but enhanced FFM and SMMI, which was likely triggered by an increase in ICW.
Adherence to the Mediterranean Diet and Its Influence on Anthropometric and Fitness Variables in High-Level Adolescent Athletes
Authors: Vélez-Alcázar Antonio E. , García-Roca Juan Alfonso , Vaquero-Cristóbal Raquel
Published: February 2024

The objectives of the present research were to analyze adherence to the Mediterranean diet (AMD), to observe which variables most affect AMD, and to analyze whether AMD affects physical fitness and anthropometric parameters in high-level adolescent athletes. A total of 96 adolescent athletes in the under-16, under-18, and under-20 categories selected by the Athletics Federation of the Region of Murcia, of whom 47 were male (age = 18.31 ± 2.31 years old) and 49 female (age = 17.27 ± 1.44 years old), participated in this study. They completed the KIDMED questionnaire to discover their AMD, as well as an anthropometric and physical condition assessment. Results: The findings show that 61.45% had an excellent degree of AMD, 31.25% a moderate one, and 7.30% a poor one. The parameters that most conditioned AMD were the consumption of fruit, vegetables, nuts, legumes, fish, breakfast cereals, and dairy products (p = 0.011–0.000). AMD did not show significant differences in anthropometric characteristics and physical fitness (p = 0.057–0.996). Conclusions: The majority of high-level adolescent athletes have a moderate or excellent AMD. The degree of AMD seems to have no influence on physical fitness and anthropometric parameters in this population.
Positive Aspects and Potential Drawbacks of Implementing Digital Teaching/Learning Scenarios in Health Professions Using Nursing Education as an Example: A Research Report from Germany
Authors: Pfeifer Lydia , Fries Sophia , Stirner Alexander , Nagel Lisa , Cohnen Christian , Aschentrup Leona , Schönbeck Marleen , Nauerth Annette , Raschper Patrizia , Herzig Tim , Wrona Kamil J.
Published: February 2024

Background: Learning arrangements in health care profession education are increasingly taking place in digital environments. Virtual reality (VR) in nursing education, as a digital element, is the subject of controversial debate. On one hand, it supports the authenticity of case studies by adding realistic perspectives and information. On the other hand, the costs of developing and maintaining software and hardware hinder its long-term implementation. Based in the German context, our aim is to promote the adoption of innovative digital methods in nursing education and to offer invaluable experiences from the field. Methods: In this paper, we describe our findings and insights from two different research projects focused on the incorporation of digital tools, particularly VR, into nursing education. Results: Starting with a brief recapitulation of the projects, we elucidate pedagogical strategies for embedding VR-driven scenarios in nursing education. Based on our experiences during the projects, we identify various positive aspects, such as changing perspective and simulating acute situations. Key findings: Although potential drawbacks remain, we advocate the long-term implementation and specific use of VR at the interface between theory and practice. Nevertheless, it is crucial to establish regular evaluation, observing the value of digitalisation, especially VR, for nursing education.