bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Microbiome Dynamics in Treated Childhood Caries: A Comparative Study
Authors: Mohamed Rasheed Zahirrah Begam , Sheng Chew Wei , Norfitriah Erika , Nasruddin Nurrul Shaqinah , Yazid Farinawati
Published: December 2024

Background: Dental caries is a multifactorial disease that results from interactions of susceptible host, cariogenic microorganisms, and fermentable carbohydrate sources. Our study explored oral microbiome shifts in children before and after dental treatment. Methods: Initial saliva samples were collected from caries free, moderate caries, and severe caries children based on the decayed, missing, and filled teeth index (DMFT/dmft) index. After three months of dental treatment, second saliva samples were gathered from the moderate and severe caries groups. The microbiota was analyzed by 16S rRNA gene-based high-throughput sequencing. Results: Most children with caries were between seven and eight years of age (40%), from middle-income group families (61%), highly educated parents (18% secondary level and 75% tertiary level) with good oral hygiene practices. There was a significant increase in alpha-diversity post-dental intervention. Firmicutes, Bacteroidota, and Proteobacteria were abundant across all samples. Post-treatment, Actinobacteria, and Firmicutes significantly decreased (p < 0.05) while Fusobacteria, Proteobacteria, Spirochaetota, and Synergistota significantly increased (p < 0.05). At genus level, a decreased trend was seen in Streptococcus, Prevotella_7, and Rothia and an increased trend was seen in Fusobacterium, Neisseria, Haemophilus, and Leptotrichia, but was not statistically significant. Conclusions: This study on Malaysian children highlights that dental caries are influenced by factors like age, socioeconomic status, and diet, with oral microbiome diversity increasing post-treatment, though some harmful bacteria persist, indicating a need for targeted oral health education and further research on probiotics’ role in caries prevention.
Physical Performance of Geriatric Women and Its Impact on Fracture Risk and Bone Mineral Density Assessed with Radiofrequency Echographic Multispectrometry (REMS)
Authors: Bischoff Elena , Popova-Belova Stanislava , Bischoff Fabian , Kirilov Nikola
Published: December 2024

Background: This study aimed to investigate the impact of physical performance of geriatric women on their fracture risk and bone mineral density (BMD) assessed with radiofrequency echographic multispectrometry (REMS). Methods: We conducted a prospective observational study to assess the physical performance, BMD and fracture risk in 182 geriatric women aged 60 years and older. BMD was measured using REMS scanning (developed by Echolight S. p. a., Lecce, Italy), and the Fracture Risk Assessment Tool (FRAX) was utilized to estimate fracture risk. Physical performance was assessed using hand grip strength (HGS), Timed Up and Go (TUG), Five Times Sit-to-Stand Test (5XSST) and Flamingo test. Results: The mean HGS of both hands differed significantly between the groups with normal BMD, osteopenia and osteoporosis measured at the lumbar spine and hip. The mean TUG time of the subjects with osteoporosis was significantly higher (13.77 s) than those with osteopenia (7.14 s) and normal BMD (6.05 s) of the hip (p = 0.024). The mean 5XSST time of the subjects with normal BMD (8.86 s) was lower than those with osteopenia (9.30 s) and osteoporosis (13.6 s) of the hip (p = 0.012). Conclusions: This study revealed strong associations between physical performance and fracture risk. Rehabilitation programs focused on strength and mobility may be essential for fracture prevention.
Hair Cortisol/DHEA-S Ratios in Healthcare Workers and Their Patients During the COVID-19 Pandemic: A Case Study
Authors: Pividori Isabella , Peric Tanja , Comin Antonella , Cotticelli Alessio , Corazzin Mirco , Prandi Alberto , Mascolo Massimo Domenico
Published: December 2024

Background: Unlike psychological distress, which has been extensively studied during the COVID-19 pandemic, the impact of the pandemic on stress hormones has been overlooked. The aim of this study is to examine the hair cortisol/dehydroepiandrosterone sulfate (DHEA-S) ratios as markers of HPA axis dysregulation in healthcare workers and their patients. Methods: A total of 200 healthcare workers and 161 “patients” patients with special healthcare needs due to chronic illness or motor disabilities were included in this study. The hormone concentrations were measured using a radioimmunoassay. Results: Our results show that the patients had significantly higher cortisol/DHEA-S ratios than the workers. A high cortisol/DHEA-S ratio in the patients reflects higher cortisol concentrations (p < 0.001) and lower DHEA-S (p < 0.05) concentrations compared to those of the healthcare workers, suggesting that they may be exposed to a greater degree of stress and a decrease in their ability to cope with their disease. The cut-off value of the hair cortisol/DHEA-S ratio in our study for detecting people with needs that require special consideration and attention was 1.46 (p ≤ 0.01). Conclusions: Assessing the hair cortisol/DHEA-S ratios in both healthcare workers and the patients allowed us to identify a non-homeostatic condition that could lead to disease and to understand psychophysical well-being during the COVID-19 pandemic. They also play a crucial role in preventive and personalized medicine.
Immune Responses Elicited by Outer Membrane Vesicles of Gram-Negative Bacteria: Important Players in Vaccine Development
Authors: Velimirov Branko , Velimirov Branko Alexander
Published: December 2024

The attractiveness of OMVs derived from Gram-negative bacteria lies in the fact that they have two biomembranes sandwiching a peptidoglycan layer. It is well known that the envelope of OMVs consists of the outer bacterial membrane [OM] and not of the inner one [IM] of the source bacterium. This implies that all outer membranous molecules found in the OM act as antigens. However, under specific conditions, some of the inner membrane proteins can be exported into the outer membrane layer and perform as antigens. A key information was that the used purification procedures for OMVs, the induction methods to increase the production of OMVs as well as the specific mutant strains obtained via genetic engineering affect the composition of potential antigens on the surface and in the lumen of the OMVs. The available literature allowed us to list the major antigens that could be defined on OMVs. The functions of the antigens within the source bacterium are discussed for a better understanding of the various available hypotheses on the biogenesis of vesicle formation. Also, the impacts of OMV antigens on the immune system using animal models are assessed. Furthermore, information on the pathways of OMVs entering the host cell is presented. An example of a bacterial infection that causes epidemic diseases, namely via Neisseria meningitidis, is used to demonstrate that OMVs derived from this pathogen elicit protective immune responses when administered as a vaccine. Furthermore, information on OMV vaccines under development is presented. The assembled knowledge allowed us to formulate a number of reasons why OMVs are attractive as vaccine platforms, as their undesirable side effects remain small, and to provide an outlook on the potential use of OMVs as a vaccine platform.
The Effect of Physiotherapy on Arthrogenic Muscle Inhibition After ACL Injury or Reconstruction: A Systematic Review
Authors: Paço Maria , Peysson Maxence , Dumont Elona , Correia Mário , Quialheiro Anna , Chaves Paula
Published: December 2024

Arthrogenic muscle inhibition (AMI) following ACL injury or reconstruction is a common issue that affects muscle activation and functional recovery. Thus, the objective of this study was to systematize the literature on the effects of physiotherapy interventions in the rehabilitation of AMI after ACL injury or reconstruction. A systematic review was conducted following the PRISMA guidelines. The risk of bias was evaluated using the PEDro scale and the Cochrane risk of bias tool. Searches were performed in the PubMed, Google Scholar, Cochrane Library, and EMBASE databases. Randomized controlled trials involving patients with ACL injuries or ACL reconstruction were included. Twenty studies were included. Fifteen evaluated the effects of exercise, showing significant improvement. Seven studies examined electrotherapy, with neuromuscular electrical stimulation and high-frequency therapy combined with exercise showing improvements in muscle strength, pain, and joint range of motion. Nine studies explored interventions like motor imagery, cryotherapy, taping, and vibration. When performed before exercise, motor imagery and cryotherapy improved cortical activity and muscle recovery. Kinesio taping reduced edema and pain better than exercise alone. Vibration showed inconsistent results across three studies. Methodological quality varied between 5 and 8 on the PEDro scale, with moderate-to-low risk of bias. Structured exercise should be the first-line intervention, but combining it with other therapies enhances rehabilitation. The study protocol was registered in the PROSPERO database (CRD42023425510).
Microstructures of Directionally Solidified Nb15Ti55Fe30 Alloy and Its Hydrogen Permeation Properties in the Presence of H2S
Authors: Yan Erhu , Huang Guanzhong , Zhang Kexiang , Tao Lizhen , Chen Hongfei , Guo Zhijie , Zhang Shuo , Wang Yihao , Zhou Zirui , Li Tangwei , Sun Lixian
Published: December 2024

Currently, the main limitations of Pd-coated Nb-TiFe dual-phase alloys include insufficient hydrogen permeability, susceptibility to hydrogen embrittlement (HE), and poor tolerance of H2S poisoning. To address these issues, this study proposes a series of improvements. First, a novel Nb15Ti55Fe30 alloy composed of a well-aligned Nb-TiFe eutectic was successfully prepared using directional solidification (DS) technology. After deposition with a Pd catalytic layer, this alloy exhibits high hydrogen permeability of 3.71 × 10−8 mol H2 m−1 s−1 Pa−1/2 at 673 K, which is 1.4 times greater than that of the as-cast counterpart. Second, to improve the H2S corrosion resistance, a new Pd88Au12 catalytic layer was deposited on the surface using a multi-target magnetic control sputtering system. Upon testing in a 100 ppm H2/H2S mixture, this membrane exhibited better resistance to bulk sulfidation and a higher permeance recovery (ca. 58%) compared to pure Pd-coated membrane. This improvement is primarily due to the lower adsorption energies of the former with H2S, which hinders the formation of bulk Pd4S. Finally, the composition region of the Pd-Au catalytic membrane with high comprehensive performance was determined for the first time, revealing that optimal performance occurs at around 12–18 at.% Au. This finding explains how this composition maintains a balance between high H2 permeability and excellent sulfur resistance. The significance of this study lies in its practical solutions for simultaneously improving hydrogen permeability and resistance to H2S poisoning in Nb-based composite membranes.
Effect of Annealing Temperature on Microstructure and Mechanical Properties of 00Cr21CuTi Stainless Steel Cold-Rolled Sheets
Authors: Ma Guocai , Sheng Jie , Gao Yang , Tuo Lixu , Li Yufeng , La Peiqing
Published: December 2024

To investigate the evolution of microstructure and mechanical properties in cold-rolled sheets of Ferritic Stainless Steel (FSS) during annealing, a series of annealing tests were performed on 00Cr21CuTi at different temperatures of 930, 990, and 1050 °C. The changes in microstructure at these annealing temperatures were characterized by optical microscopy (OM), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and electron back-scattered diffraction (EBSD). The influence of annealing temperature on mechanical properties was assessed utilizing a universal tensile testing machine and a laser confocal microscope. The results indicated a gradual decrease in yield strength and tensile strength with increasing annealing temperature, whereas elongation exhibited an upward trend. At an annealing temperature of 930 °C, the yield strength, tensile strength, and elongation of the steel were 251 MPa, 409 MPa, and 30.9%, respectively, with a high product of strength plastic 12.64 GPa·%. This result represented an optimal balance between comprehensive strength and plasticity.
Interlayer Friction Mechanism and Scale Effects in Ultra-Thin TA1 Titanium Alloy/Carbon Fiber-Reinforced Plastic Laminates
Authors: Zhang Quanda , Liu Zeen , Song Guopeng , Sun Fuzhen , Liu Zizhi , Li Xiaoxu , Chen Wengang
Published: December 2024

Fiber metal laminates (FMLs) are a novel lightweight composite material, predominantly utilized in the aerospace sector for large-scale components like skin panels and fuselages. However, research on FMLs in the microsystem domain remains limited. Additionally, they are influenced by scale effects, rendering macroscopic forming theories inadequate for microforming applications. The application of ultra-thin fiber metal laminates in the microsystem field is hindered by this constraint. This paper investigates the friction performance of ultra-thin TA1 titanium alloy/carbon fiber-reinforced plastic (CFRP) laminates at the microscale. The content of the epoxy resin used is 38.0 ± 3.0%. Friction tests on ultra-thin TA1/CFRP laminates were conducted based on the Striebeck friction theory model. The effects of factors such as the weaving method, ply angle, normal force, tensile speed, and temperature on friction performance are explored in the study. Furthermore, the influences of geometric scale and grain scale on friction performance are examined. Geometric scale effects indicate that an increase in laminate width leads to an increase in the friction coefficient. Grain-scale effects demonstrate that as grain size increases, the friction coefficient also increases, attributed to reduced grain boundaries, increased twinning, and increased surface roughness of the metal. Finally, surface morphology analysis of the metal and fiber after friction tests further confirms the influence of grain size on the friction coefficient. Through detailed experimental design, result analysis and graphical representation, this paper provides a scientific basis for understanding and predicting the friction behavior of ultra-thin TA1/CFRP laminates.
The Expanded Phases Formed in Stainless Steels by Means of Low-Temperature Thermochemical Treatments: A Corrosion Perspective
Authors: Borgioli Francesca
Published: December 2024

Surface engineering of stainless steels using thermochemical treatments at low temperatures has been the subject of intensive research for enhancing the surface hardness of these alloys without impairing their corrosion resistance. By using treatment media rich in nitrogen and/or carbon, it is possible to inhibit chromium compound formation and obtain supersaturated solid solutions, known as expanded phases, such as expanded austenite or S-phase in austenitic stainless steels, expanded ferrite in ferritic grades, and expanded martensite in martensitic grades. These low-temperature treatments produce a significant increase in surface hardness, which improves wear and fatigue resistance. However, the corrosion behavior of the modified surface layers remains of paramount importance. In the international literature, many studies on this topic are reported, but the results are not always univocal, and there are still open questions. In this review, the corrosion behavior of the expanded phases and the modified layers in which they are present is critically analyzed and discussed. The relationships between the phase composition and the microstructure of the modified layers and the corrosion resistance are highlighted while also considering the different test conditions. Furthermore, corrosion test methods are discussed, and suggestions are given for improving the measurements. Finally, perspectives on future directions for investigation are suggested for encouraging further research.
Effect of Stable and Transient Cavitation on Ultrasonic Degassing of Al Alloy
Authors: Lee Youngki , Kim Jongmin , Ha Taekyu , Kang Byungil , Kim Youngjig
Published: December 2024

Cavitation is a critical phenomenon for improving melt quality in casting processes by reducing hydrogen porosity, and it can be classified into two major types based on bubble dynamics, stable and transient cavitation. In this study, the relationship between stable and transient cavitation and the degassing efficiency of A356 alloy was evaluated. Cavitation intensity was quantified based on the Karman vortices method, and the measured cavitation intensities were processed through FFT transformation to analyze the acoustic spectra. The line spectrum and continuous spectrum were characterized separately to quantify stable and transient cavitation in distilled water. Negligible change in stable cavitation was observed, while transient cavitation increased with amplitude. On the other hand, both stable and transient cavitation increased proportionally with frequency. By employing the characterized cavitation indices, the effects of stable and transient cavitation on ultrasonic degassing of A356 were assessed. It was confirmed that transient cavitation was the dominant factor in the degassing before the degassing efficiency reached a steady state. This study clearly demonstrates that optimizing frequency to enhance transient cavitation is a more effective approach for increasing intensity and, consequently, improving degassing efficiency.
Application of Tungsten Nanopowder in Manual Metal Arc, Metal Inert Gas, and Flux-Cored Arc Welding Surfacing
Authors: Zernin Evgenii , Petrova Ekaterina , Scherbakov Alexander , Pozdeeva Ekaterina , Blohin Anatolij
Published: December 2024

The main directions and fields of the application of metal nanopowders in joining technologies are considered. Based on this analysis, the purpose of this research was to determine the effect of tungsten nanopowder on the structure and properties of the deposited metal. In order to increase the efficiency of using tungsten nanopowder for modification, it is necessary to ensure the introduction of nanopowder into the low-temperature zone of the molten metal during surfacing. To study the metal, microstructural analysis was performed, and the microhardness of the deposited joint was determined. On the basis of the conducted studies, a change in the structure of the deposited metal and an increase in mechanical properties were revealed. A conclusion is made about the effect of tungsten nanopowder on the metal modification process during manual metal arc, metal inert gas, and flux-cored arc welding. Based on the conducted studies, it was found that the introduction of tungsten nanopowder into the low-temperature zone of the molten metal ensures the modification of the surfacing and induces an increase in the microhardness of the deposited metal. At the same time, grains of polyhedral morphology are formed at the surface, and the structure of oriented dendrites at the boundary of fusion with the base metal is also revealed, showing the peculiarities of the distribution of microhardness in various surfacing methods. The minimum and maximum values of microhardness depend not only on the nanopowder but also on the method of its introduction into the molten metal.
Analysis of the Structure and Properties of As-Built and Heat-Treated Wire-Feed Electron Beam Additively Manufactured (WEBAM) Ti–4Al–3V Spherical Pressure Vessel
Authors: Chumaevskii Andrey , Tarasov Sergey , Gurianov Denis , Moskvichev Evgeny , Rubtsov Valery , Savchenko Nikolay , Panfilov Aleksander , Korsunsky Alexander M. , Kolubaev Evgeny
Published: December 2024

In the present work, a high-pressure spherical vessel was fabricated from Ti–4Al–3V titanium alloy using wire-feed electron beam additive manufacturing and characterized for tightness at high pressure. Studies have been carried out to characterize the microstructures and properties of the vessel’s material in four states: as-built (BM), annealed at 940 °C with cooling in air (HT1 treatment), quenched in water from 940 °C (HT2 treatment), and quenched with subsequent annealing at 540 °C (HT3 treatment). The microstructure of the as-built (BM) samples was composed of grain boundary α-Ti and α/β lath colonies located within the columnar primary β-Ti grain boundaries. The ultimate tensile strength of the as-built material was in the range of 582 to 632 MPa, i.e., significantly lower than that of the source Ti–4Al–3V alloy wire. The subtransus HT1 heat treatment allowed β→α″ transformation, while both HT2 and HT3 resulted in improved tensile strength due to the transformation of β-Ti into α/α′-Ti and the decomposition of α′ into α/β structures, respectively.
A Study of the Effect of Roughness on the Three-Body Wear Mechanism from a Microscopic Point of View: Asperity Peak Removal
Authors: Wei Tangshengjie , Zhou Ziyi , Ling Xue , Lv Minghao , Di Yunfei , Qin Kun , Zhou Qin
Published: December 2024

The presence of particles leads to varying degrees of mass loss on a metal sealing surface, which severely affects the seal’s lifespan. Understanding the complex wear mechanism and optimizing the surface roughness morphology are particularly important in engineering. By characterizing the surface of the metal (SS 304) with different roughness parameters Ra, Rp, Rpk, Rpc and Rku, the variation mode of mass loss under abrasive wear conditions was revealed. Unlike traditional two-body wear, the involvement of abrasive particles significantly impacts surface Ra and other surface morphologies (asperity peak features). A contact model for metal rough surfaces, distinct from two-body contact, was established to clarify the changes in removal mechanisms. It was found that the change in the contact between the particle and the asperity peak led to a change in the mass loss and guided the appropriate metal roughness range: Ra 0.05 μm and Ra 0.6–0.8 μm. In addition, it was found that the removal of asperity peaks is holistic under low roughness, and only parts of asperity peaks are removed under high roughness. Notably, the metrological methods used in this study supplement existing roughness measurements. By exploring the complex removal mechanism of asperity peaks, micro-scale guidance for surface (texture) design, machining, and optimization is provided.
Recent Advances in Piezoelectric Compliant Devices for Ultrahigh-Precision Engineering
Authors: Wu Zeyi , Wu Zehao , Chen I-Ming , Xu Qingsong
Published: December 2024

With advancements in small-scale research fields, precision manipulation has become crucial for interacting with small objects. As research progresses, the demand for higher precision in manipulation has led to the emergence of ultrahigh-precision engineering (UHPE), which exhibits significant potential for various applications. Traditional rigid-body manipulators suffer from issues like backlash and friction, limiting their effectiveness at smaller-scale applications. Smart materials, particularly piezoelectric materials, offer promising solutions with their rapid response and high resolution, making them ideal for creating efficient piezoelectric transducers. Meanwhile, compliant mechanisms, which use elastic deformation to transmit force and motion, eliminate inaccuracies induced by rigid-body mechanisms. Integrating piezoelectric transducers and compliant mechanisms into piezoelectric compliant devices enhances UHPE system performance. This paper reviews the recent advances in piezoelectric compliant devices. By focusing on the utilization of piezoelectric transducers and compliant mechanisms, their applications in perception, energy harvesting, and actuation have been surveyed, and future research suggestions are discussed.
A Thermal Cycler Based on Magnetic Induction Heating and Anti-Freezing Water Cooling for Rapid PCR
Authors: Xie Yaping , Jiang Qin , Chang Chang , Zhao Xin , Yong Haochen , Ke Xingxing , Wu Zhigang
Published: December 2024

Distinguished by its exceptional sensitivity and specificity, Polymerase Chain Reaction (PCR) is a pivotal technology for pathogen detection. However, traditional PCR instruments that employ thermoelectric cooling (TEC) are often constrained by cost, efficiency, and performance variability resulting from the fluctuations in ambient temperature. Here, we present a thermal cycler that utilizes electromagnetic induction heating at 50 kHz and anti-freezing water cooling with a velocity of 0.06 m/s to facilitate rapid heating and cooling of the PCR reaction chamber, significantly enhancing heat transfer efficiency. A multi-physics theoretical heat transfer model, developed using the digital twin approach, enables precise temperature control through advanced algorithms. Experimental results reveal average heating and cooling rates of 14.92 °C/s and 13.39 °C/s, respectively, significantly exceeding those of conventional methods. Compared to commercial PCR instruments, the proposed system further optimizes cost, efficiency, and practicality. Finally, PCR experiments were successfully performed using cDNA (Hepatitis B virus) at various concentrations.
Petrogenesis of Permian Granodiorite and Diorite in Eastern Jilin Province and Its Constraints on the Late-Stage Evolution of the Paleo-Asian Ocean
Authors: Tang Yao , Sun Deyou , Deng Changzhou , Gou Jun , Fu Changliang , Yang Dongguang
Published: December 2024

The Solonker-Xar Moron-Changchun-Yanji Suture Zone is the result of the final closure of the Paleo-Asian Ocean (PAO). However, the closure time of the PAO in Northeast China remains controversial. The Hunchun area is located in the easternmost part of the Solonker-Xar Moron-Changchun-Yanji Suture Zone. Tectonism and magmatism in the Hunchun area can provide important information for understanding the late-stage evolution of the PAO. In this study, our zircon U-Pb ages show that the granodiorites and diorites in the Hunchun were formed at 282.3–251.4 Ma. This geochronological evidence suggests prolonged Permian magmatism in the Hunchun area. Whole-rock geochemistry, zircon trace, and Lu-Hf isotope data show that all the intrusive rocks are mainly calc-alkaline series to arc tholeiite series. Granodiorites are I-type granites formed by the partial melting of juvenile lower crust derived from the mantle. Diorites show similar characteristics to the sanukitic high-Mg diorite and are formed by the partial melting of the depleted mantle metasomatized by subduction sediments and/or slab-derived fluids. These results indicate that the Permian diorites and granodiorites in the Hunchun area formed in an active continental margin setting related to the subduction of the PAO plate. Significantly, sudden changes in the whole-rock Sr/Y and (La/Yb)N ratios and zircon εHf(t) values are observed in the Late Permian-Early Triassic igneous rocks in the eastern Central Asian Orogenic Belt (CAOB). This indicates that the final closure of the PAO in Northeast China likely occurred in the Late Permian-Early Triassic.
Transport of Au–Ag Nanoparticles in Dense Carbon Dioxide Fluid of the Middle Crust
Authors: Prokofiev Vsevolod Yu. , Banks David A. , Lobanov Konstantin V. , Selektor Sofiya L. , Milichko Valentin A. , Borovikov Andrey A. , Chicherov Mikhail V.
Published: December 2024

Individual fluid inclusions with dense carbon dioxide hosted in quartz from the gold-bearing interval penetrated by the SD-3 Kola Superdeep Borehole were studied using modern techniques. The composition and density of the carbon dioxide fluid were determined by Raman spectroscopy and microthermometry. The density of the fluid is 0.37–1.14 g/cm3 and contains minor admixtures of nitrogen (0.3–1.8 mol %) and water (0.1–0.4 mol %). LA-ICP-MS data indicate that the carbon dioxide fluid inclusions contain high concentrations of Au (1–2611 ppm) and Ag (1–4389 ppm), and high-precision optical data indicate that the high-density CO2 fluid of the inclusions contains Au–Ag nanoparticles. Evidently, gold and silver were transported from the Earth’s mantle to the crust by high-density carbon dioxide fluid in the form of nanoparticles.
Assessing the Impact of Surface Blast Design Parameters on the Performance of a Comminution Circuit Processing a Copper-Bearing Ore
Authors: Losaladjome Mboyo Hervé , Huo Bingjie , Mulenga François K. , Mabe Fogang Pieride , Kalenga Kaunde Kasongo Jimmy
Published: December 2024

Open-pit mining remains the dominant method for copper extraction in current operations, with blasting playing a pivotal role in the efficiency of downstream processes such as loading, hauling, crushing, and milling. This study assesses the impact of surface blast design parameters on the performance of a comminution circuit processing a copper-bearing ore. The analysis focuses on important design parameters such as burden, spacing, stemming, and powder factor, evaluating their influence on the fragment size distribution and downstream comminution circuit performance. Using the Kuz-Ram model, four novel blast designs are compared against a baseline to predict the size distribution of rock fragments (X80). Key performance indicators throughput and specific energy consumption are calculated to evaluate the comminution circuit performance. Results demonstrated that reducing the X80 from 500 mm to 120 mm led up to a 20% increase in throughput and a 29% reduction in total specific energy consumption. Furthermore, achieving finer particle sizes through more intensive blasting contributed to a reduction in total operating costs by up to 12%. These findings provide valuable insights for optimizing blast design to improve comminution circuit performance, contributing to sustainable mining practices by reducing energy consumption, operating costs, and the environmental footprint of mining operations.
Development of a Detailed Chemical Kinetic Model for 1-Methylnaphthalene
Authors: Liang Junjie , Zhang Qianlong , Heng Yijun , Li Gesheng , Yang Ke , Wang Ruiyang , Dong Fan , Zhu Neng
Published: December 2024

1-Methylnaphthalene is a critical component for constructing fuel surrogates of diesel and aviation kerosene. However, the reaction pathways of 1-methylnaphthalene included in existing detailed chemical kinetic models vary from each other, leading to discrepancies in the simulation of ignition and oxidation processes. In the present study, reaction classes and pathways involved in the combustion of 1-methylnaphthalene were analyzed, and effects of rate constants of reactions related to 1-methylnaphthalene and its significant intermediates on ignition delay times and species concentration profiles were discussed, involving hydrogen abstraction and substitution reactions of 1-methylnaphthalene, oxidation, isomerization, and addition reactions of 1-naphthylmethyl, hydrogen abstraction and oxidation reactions of indene, as well as the oxidation of indenyl and naphthalene. On this basis, a new detailed chemical kinetic model for 1-methylnaphthalene was developed, which includes 1389 species and 7185 reactions. The validation of this mechanism shows that it can predict accurately the available experimental ignition delay times, species concentration profiles, and laminar flame speeds of 1-methylnaphthalene. Finally, reaction paths and sensitivity analysis of ignition delay times were performed using the proposed reaction mechanism, and the result shows that the conversion of 1-methylnaphthalene to 1-naphthaldehyde plays an important role in its ignition.
Water–Gas Shift over Pt Nanoparticles Dispersed on CeO2 and Gadolinium-Doped Ceria (GDC) Supports with Specific Nano-Configurations
Authors: Androulakis Athanasios , Nikolaraki Ersi , Drosou Catherine , Papazisi Kalliopi Maria , Balomenou Stella , Tsiplakides Dimitrios , Froudas Konstantinos G. , Trikalitis Pantelis N. , Gournis Dimitrios P. , Panagiotopoulou Paraskevi , Yentekakis Ioannis V.
Published: December 2024

The water–gas shift (WGS) reaction is one of the most significant reactions in hydrogen technology since it can be used directly to produce hydrogen from the reaction of CO and water; it is also a side reaction taking place in the hydrocarbon reforming processes, determining their selectivity towards H2 production. The development of highly active WGS catalysts, especially at temperatures below ~450 °C, where the reaction is thermodynamically favored but kinetically limited, remains a challenge. From a fundamental point of view, the reaction mechanism is still unclear. Since specific nanoshapes of CeO2-based supports have recently been shown to play an important role in the performance of metal nanoparticles dispersed on their surface, in this study, a comparative study of the WGS is conducted on Pt nanoparticles dispersed (with low loading, 0.5 wt.% Pt) on CeO2 and gadolinium-doped ceria (GDC) supports of different nano-morphologies, i.e., nanorods (NRs) and irregularly faceted particle (IRFP) CeO2 and GDC, produced by employing hydrothermal and (co-)precipitation synthesis methods, respectively. The results showed that the support’s shape strongly affected its physicochemical properties and in turn the WGS performance of the dispersed Pt nanoparticles. Nanorod-shaped CeO2,NRs and GDCNRs supports presented a higher specific surface area, lower primary crystallite size and enhanced reducibility at lower temperatures compared to the corresponding irregular faceted CeO2,IRFP and GDCIRFP supports, leading to up to 5-fold higher WGS activity of the Pt particles supported on them. The Pt/GDCNRs catalyst outperformed all other catalysts and exhibited excellent time-on-stream (TOS) stability. A variety of techniques, namely N2 physical adsorption–desorption (the BET method), scanning and transmission electron microscopies (SEM and TEM), powder X-ray diffraction (PXRD) and hydrogen temperature programmed reduction (H2-TPR), were used to identify the texture, structure, morphology and other physical properties of the materials, which together with the in situ diffuse reflectance Fourier transform infrared spectroscopy (DRIFTS) and detailed kinetic studies helped to decipher their catalytic behavior. The enhanced metal–support interactions of Pt nanoparticles with the nanorod-shaped CeO2,NRs and GDCNRs supports due to the creation of more active sites at the metal–support interface, leading to significantly improved reducibility of these catalysts, were concluded to be the critical factor for their superior WGS activity. Both the redox and associative reaction mechanisms proposed for WGS in the literature were found to contribute to the reaction pathway.
Weizmannia coagulans BC99 Enhances Intestinal Barrier Function by Modulating Butyrate Formation to Alleviate Acute Alcohol Intoxication in Rats
Authors: Li Cheng , Zhai Shirui , Duan Mengyao , Cao Li , Zhang Jie , Wang Yao , Wu Ying , Gu Shaobin
Published: December 2024

Background/Objectives: Probiotics have great potential in improving acute alcohol intoxication. The aim of this study was to investigate the mitigating effect and mechanism of action of Weizmannia coagulans BC99 on acute alcohol intoxication (AAI) in SD rats. Methods: BC99 was divided into different doses administered by gavage to rats, and a rat model of acute alcohol intoxication was established by multiple gavages of excess alcohol. Results: Our study demonstrated that W. coagulans BC99 intervention significantly prolonged the latency period of intoxication; significantly attenuated alcohol-induced lipid elevation, liver injury, hepatic inflammation, and intestinal barrier damage; and lowered plasma endotoxin (LPS) levels in rats. In addition, W. coagulans BC99 could effectively restore the balance of intestinal flora, increase the abundance of Lachnospiraceae_NK4A136, Prevotellaceae_NK3B31, Parabacteroides, and Ralstonia, and thus increase the content of intestinal short-chain fatty acids (SCFAs), especially butyric acid. Moreover, we demonstrated through sodium butyrate validation experiments that butyrate could attenuate intestinal barrier damage and reduce the diffusion of LPS, thereby reducing liver inflammation. Conclusions: In conclusion, W. coagulans BC99 ameliorates acute alcohol intoxication in rats by increasing the abundance of butyrate-producing genera and thereby increasing butyrate abundance to alleviate intestinal barrier injury.
The Impact of Maternal Gestational Diabetes Mellitus on Minipuberty in Boys
Authors: Kowalcze Karolina , Burgio Sofia , Ott Johannes , Gullo Giuseppe , Zaami Simona , Krysiak Robert
Published: December 2024

Background/Objectives: Minipuberty is thought to play an important role in the sexual maturation of infants. Maternal disorders during pregnancy were found to have an impact on the activity of the reproductive axis in the first year of life. This prospective, matched, cohort study was aimed at investigating whether the course of minipuberty in boys is affected by maternal gestational diabetes mellitus (GDM). Methods: The study population consisted of three matched groups of boys: infants born to women with poorly controlled GDM, sons of women with adequately controlled GDM, and infants of healthy women with normal carbohydrate tolerance during pregnancy (control group). Salivary levels of testosterone, androstenedione, DHEA-S and estradiol, and urinary concentrations of FSH and LH were repeatedly measured over the first 12 months of life. Hormone levels were correlated with the size of genital organs (testicular volume and penile length), which were measured at each visit. Results: Compared with the remaining groups, the male offspring of women with poorly controlled GDM were characterized by higher concentrations of both gonadotropins, higher salivary testosterone levels, lower salivary DHEA-S concentrations, and longer periods of detection for LH and testosterone. Levels of gonadotropin, testosterone and DHEA-S in sons of mothers with poorly controlled GDM correlated with mean levels of glycated hemoglobin during pregnancy. Moreover, the infant boys assigned to this group were characterized by larger sizes of the testes and penis. Over the entire study period, there were no differences in hormone levels, testicular volume and penile length between sons of adequately treated women with GDM and sons of healthy women. Conclusions: The obtained results indicate that GDM, if poorly controlled, may affect the activity of the reproductive axis and postnatal growth of male genital organs in the offspring.
Genome-Wide Approach of Gene–Nutrient Intake Interaction Study for Essential Hypertension in a Large Korean Cohort (KoGES)
Authors: Song Youhyun , Choi Ja-Eun , Park Jae-Min , Kwon Yu-Jin , Hong Kyung-Won , Lee Ji-Won
Published: December 2024

Background/Objectives: There is limited evidence on gene-nutrient interaction associated with hypertension (HTN). We examined interactions between genotypes and various nutrients that influenced high blood pressure (BP). Methods: Data were obtained from a total of 50,808 participants from the Korean Genome and Epidemiology Study (KoGES). Dietary intake was assessed by a food frequency questionnaire, and dietary reference intakes (DRIs) were set. We performed genome-wide association analyses (GWAS) and subsequent interaction analyses with genome-wide significant SNPs to identify genomic loci that interact with specific nutrients associated with HTN. Results: We identified one locus near the CUB and Sushi Multiple Domains 1 (CSMD1) gene that showed interaction with dietary iron and vitamin B6 (Vit.B6) intake and significantly influenced HTN risk. Among the individuals consuming iron above DRI (9.5 mg/day for men, 9.25 mg/day for women), carriers of the rs13282715 minor allele (A) at 8p23.2 showed a lower risk of HTN than those who did not (odds ratio [OR] 0.723, 95% confidence interval [CI] (0.644–0.813), p-value 4.858 × 10−8; interaction p-value 1.336 × 10−3). Among the individuals consuming Vit.B6 above DRI (1.5 mg/day for men, 1.4 mg/day for women), carriers of the same variant rs13282715 minor allele (A) also showed a lower risk of HTN (OR 0.733, 95% CI 0.733 (0.656–0.819), p-value 4.121 × 10−8; interaction p-value 7.183 × 10−4). Conclusions: We identified a novel gene-nutrient interaction regarding dietary iron and Vit.B6 intake affecting the risk of HTN in Korean adults. This suggests individuals with the variant may benefit from lower HTN risk from dietary intervention of iron and Vit.B6 intake. Further studies with larger diverse populations are warranted to validate our findings.
Influence of CReatine Supplementation on mUScle Mass and Strength After Stroke (ICaRUS Stroke Trial): A Randomized Controlled Trial
Authors: Souza Juli T. , Minicucci Marcos F. , Ferreira Natália C. , Polegato Bertha F. , Okoshi Marina P. , Modolo Gabriel P. , Leal-Pereira Filipe W. , Phillips Bethan E. , Atherton Philip J. , Smith Kenneth , Wilkinson Daniel J. , Gordon Adam L. , Tanni Suzana E. , Costa Vladimir E. , Fernandes Maria F. , Bazan Silméia G. , Zornoff Leonardo M. , Paiva Sérgio R. , Bazan Rodrigo , Azevedo Paula S.
Published: December 2024

Background/Objectives: The acute phase of stroke is marked by inflammation and mobility changes that can compromise nutritional status. This study was a randomized, double-blind, placebo-controlled trial evaluating the effectiveness of creatine supplementation for older people during seven days of hospitalization for stroke compared to usual care. Method: The primary outcome measures were changes in functional capacity, strength, muscle mass, and muscle degradation. The secondary outcomes were changes in serum biomarkers related to inflammation, fibrosis, anabolism, and muscle synthesis. In addition, a follow-up 90 days after the stroke verified functional capacity, strength, quality of life, and mortality. Following admission for an acute stroke, participants received either creatine (10 g) or a visually identical placebo (10 g) orally twice daily. Both groups received supplementation with protein to achieve the goal of 1.5 g of protein/kg of body weight/day and underwent daily mobility training during seven days of hospitalization. Results: Thirty older people were included in two similar groups concerning baseline attributes (15—treatment/15—placebo). Conclusions: Creatine supplementation did not influence functional capacity, strength, or muscle mass during the first 7 days or outcomes 90 days after stroke. There were no serious adverse events associated with creatine supplementation. However, it decreased progranulin levels, raising a new possibility of creatine action. This finding needs further exploration to understand the biological significance of creatine–progranulin interaction.
Genomic Diversity and Evolution of Identified SARS-CoV-2 Variants in Iraq
Authors: Al-Mankhee Ahmed A. , Moatasim Yassmin , El Taweel Ahmed , Gomaa Mokhtar , Rabiee Omar A. , Gado Marwa M. , Barakat Ahmed B. , Ali Mohamed A. , El-Shesheny Rabeh
Published: December 2024

The COVID-19 pandemic caused by the SARS-CoV-2 virus continues to circulate worldwide, causing the deaths of millions of people. The continuous circulation of the virus, its genetic diversity, the emergence of new variants with increased transmissibility, and/or the capacity of the virus to escape from the immune system constitute a major public health concern. In our study, we aimed to characterize SARS-CoV-2 strains in Iraq from the first introduction until the end of 2023, and to identify their variants, lineages, clades, and mutation patterns. All published Iraqi full genome sequences (2020–2023) were obtained from Global Initiative on Sharing All Influenza Data (GISAID) and subjected to molecular characterization along with 19 samples of full genome sequences that were collected during the fifth and sixth waves of the SARS-CoV-2 pandemic in this study. Next-generation sequencing was performed using an Illumina MiSeq system, and phylogenetic analysis was performed for all the Iraqi sequences. Three established global platforms, GISAID, Nextstrain, and PANGO, were used for the classification of isolates into distinct clades, variants, and lineages. Six wave peaks of COVID-19 cases have been identified in Iraq, resulting in approximately 2,400,000 cumulative confirmed cases and more than 25,000 deaths. Our study revealed patterns of circulation and dominance of SARS-CoV-2 clades and their lineages in the pandemic waves in the country.
Association of Molecular Detections of Microsporidia in Stool Samples with Clinical and Immunological Parameters in Ghanaian HIV Patients
Authors: Frickmann Hagen , Sarfo Fred Stephen , Norman Betty Roberta , Dompreh Albert , Asibey Shadrack Osei , Boateng Richard , Kuffour Edmund Osei , Tanida Konstantin , Di Cristanziano Veronica , Feldt Torsten , Eberhardt Kirsten Alexandra
Published: December 2024

Although the etiological relevance of the detection of microsporidia in human stool samples remains uncertain, the immunological status of patients has been posited as an important determinant of potential clinical impact of these parasites. To further assess the interplay between the epidemiology of microsporidia and immunological markers, we conducted a study utilizing real-time PCR targeting Enterocytozoon bieneusi, Encephalitozoon cuniculi, Encephalitozoon hellem, and Encephalitozoon intestinalis, combined in a single fluorescence channel. The study involved a cohort of 595 clinically and immunologically well-characterized Ghanaian HIV patients, alongside 82 HIV-negative control individuals from Ghana. While microsporidial DNA was absent in HIV-negative controls, among people living with HIV, its prevalence was inversely correlated with CD4+ lymphocyte counts: 6.0% in those with >500 cells/µL, 9.5% in those with 200–499 cells/µL, 13.8% in those with 50–199 cells/µL, and 27.5% in those with <50 cells/µL, respectively. Correspondingly, microsporidia were more frequently detected in HIV patients who were not receiving antiretroviral therapy. There were no associations with clinical symptoms including gastroenteritis with the exception of a non-significant trend towards weight loss. HLA-DR+CD38+ on CD4+ T lymphocytes, a marker of immune activation, as well as Ki67, a marker of cell proliferation, were increased on CD4+ T lymphocytes in HIV patients with microsporidia, suggesting an immune response may be triggered. In conclusion, our assessment indicates a higher prevalence of microsporidia in the stool of Ghanaian HIV patients, which varies with their immunological status. However, given the lack of clear associations with clinical symptoms, the detection of microsporidia in the stool of HIV patients needs to be cautiously interpreted in clinical settings.