The 2023 MDPI Annual Report has
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15 pages, 6025 KiB  
Article
Surface-Enhanced Raman Spectroscopy of Ammonium Nitrate Using Al Structures, Fabricated by Laser Processing of AlN Ceramic
by Petar Atanasov, Anna Dikovska, Rosen Nikov, Genoveva Atanasova, Katarzyna Grochowska, Jakub Karczewski, Naoki Fukata, Wipakorn Jevasuwan and Nikolay Nedyalkov
Materials 2024, 17(10), 2254; https://doi.org/10.3390/ma17102254 (registering DOI) - 10 May 2024
Abstract
This work presents results on laser-induced surface structuring of AlN ceramic and its application in Surface-Enhanced Raman Spectroscopy (SERS). The laser processing is performed by nanosecond pulses in air and vacuum. Depending on the processing conditions, different surface morphology can be obtained. The [...] Read more.
This work presents results on laser-induced surface structuring of AlN ceramic and its application in Surface-Enhanced Raman Spectroscopy (SERS). The laser processing is performed by nanosecond pulses in air and vacuum. Depending on the processing conditions, different surface morphology can be obtained. The ablation process is realized by ceramic decomposition as the formation of an aluminium layer is detected. The efficiency of the fabricated structures as active substrates in SERS is estimated by the ability of the detection of ammonium nitrate (NH4NO3). It is conducted for Raman spectrometer systems that operate at wavelengths of 514 and 785 nm where the most common commercial systems work. The obtained structures contribute to enhancement of the Raman signal at both wavelengths, as the efficiency is higher for excitation at 514 nm. The limit of detection (LOD) of ammonium nitrate is estimated to be below the maximum allowed value in drinking water. The analysis of the obtained results was based on the calculations of the near field enhancement at different conditions based on Finite Difference Time Domain simulation and the extinction spectra calculations based on Generalized Mie scattering theory. The structures considered in these simulations were taken from the SEM images of the real samples. The oxidation issue of the ablated surface was studied by X-ray photoelectron spectroscopy. The presented results indicated that laser structuring of AlN ceramics is a way for fabrication of Al structures with specific near-field properties that can be used for the detection of substances with high social impact. Full article
(This article belongs to the Special Issue Advances in Laser Processing Technology of Materials)
15 pages, 3488 KiB  
Article
A Two-Port Dual-Band Dual-Circularly-Polarized Dielectric Resonator Antenna
by Thai Van Trinh, Son Trinh-Van, Kang-Yoon Lee, Younggoo Yang and Keum Cheol Hwang
Appl. Sci. 2024, 14(10), 4062; https://doi.org/10.3390/app14104062 (registering DOI) - 10 May 2024
Abstract
This paper presents the design of a two-port dual-band dual-circularly-polarized dielectric resonator antenna (DRA). The proposed DRA is formed by stacking two dielectric resonators (DRs) of different shapes, including a hexagonal DR on top and a cross-shaped DR on the bottom. It is [...] Read more.
This paper presents the design of a two-port dual-band dual-circularly-polarized dielectric resonator antenna (DRA). The proposed DRA is formed by stacking two dielectric resonators (DRs) of different shapes, including a hexagonal DR on top and a cross-shaped DR on the bottom. It is designed to resonate at two near-degenerate orthogonal modes of TE111 and TE113, and an aperture-coupled feeding through a cross-like slot is used to achieve dual-band impedance matching simultaneously for right- and left-handed circular polarizations. Tests were conducted on a prototype working in C-band to verify the design concept. The experiment results demonstrate that the proposed DRA has exceptional performance with measured −10 dB reflection bandwidths of 24.4% and 17.4%, 3 dB axial ratio bandwidths of 21.2% and 16.3%, and maximum gains of 5.64 and 8.13 dBic for the lower and upper bands, respectively. Moreover, the measured channel isolation is more than 15.8 dB. The results obtained from the experiments show good agreement with the simulation, and hence, it can be concluded that the proposed DRA is a promising solution that can be used for various wireless communication applications. Full article
(This article belongs to the Section Electrical, Electronics and Communications Engineering)
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17 pages, 15333 KiB  
Article
Modeling Climate Characteristics of Qinghai Lake Ice in 1979–2017 by a Quasi-Steady Model
by Hong Tang, Yixin Zhao, Lijuan Wen, Matti Leppäranta, Ruijia Niu and Xiang Fu
Remote Sens. 2024, 16(10), 1699; https://doi.org/10.3390/rs16101699 (registering DOI) - 10 May 2024
Abstract
Lakes on the Qinghai Tibet Plateau (QTP) are widely distributed spatially, and they are mostly seasonally frozen. Due to global warming, the thickness and phenology of the lake ice has been changing, which profoundly affects the regional climate evolution. There are a few [...] Read more.
Lakes on the Qinghai Tibet Plateau (QTP) are widely distributed spatially, and they are mostly seasonally frozen. Due to global warming, the thickness and phenology of the lake ice has been changing, which profoundly affects the regional climate evolution. There are a few studies about lake ice in alpine regions, but the understanding of climatological characteristics of lake ice on the QTP is still limited. Based on a field experiment in the winter of 2022, the thermal conductivity of Qinghai Lake ice was determined as 1.64 W·m−1·°C−1. Airborne radar ice thickness data, meteorological observations, and remote sensing images were used to evaluate a quasi-steady ice model (Leppäranta model) performance of the lake. This is an analytic model of lake ice thickness and phenology. The long-term (1979–2017) ice history of the lake was simulated. The results showed that the modeled mean ice thickness was 0.35 m with a trend of −0.002 m·a−1, and the average freeze-up start (FUS) and break-up end (BUE) were 30 December and 5 April, respectively, which are close to the field and satellite observations. The simulated trend of the maximum ice thickness from 1979 to 2017 (0.004 m·a−1) was slightly higher than the observed result (0.003 m·a−1). The simulated trend was 0.20 d·a−1 for the FUS, −0.34 d·a−1 for the BUE, and −0.54 d·a−1 for the ice duration (ID). Correlation and detrending analysis were adopted for the contribution of meteorological factors. In the winters of 1979–2017, downward longwave radiation and air temperature were the two main factors that had the best correlation with lake ice thickness. In a detrending analysis, air temperature, downward longwave radiation, and solar radiation contributed the most to the average thickness variability, with contributions of 42%, 49%, and −48%, respectively, and to the maximum thickness variability, with contributions of 41%, 45%, and −48%, respectively. If the six meteorological factors (air temperature, downward longwave radiation, solar radiation, wind speed, pressure, and specific humidity) are detrending, ice thickness variability will increase 83% on average and 87% at maximum. Specific humidity, wind, and air pressure had a poor correlation with ice thickness. The findings in this study give insights into the long-term evolutionary trajectory of Qinghai Lake ice cover and serve as a point of reference for investigating other lakes in the QTP during cold seasons. Full article
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30 pages, 1004 KiB  
Article
Data-Driven Strategies for Complex System Forecasts: The Role of Textual Big Data and State-Space Transformers in Decision Support
by Huairong Huo, Wanxin Guo, Ruining Yang, Xuran Liu, Jingyi Xue, Qingmiao Peng, Yiwei Deng, Xinyi Sun and Chunli Lv
Systems 2024, 12(5), 171; https://doi.org/10.3390/systems12050171 (registering DOI) - 10 May 2024
Abstract
In this research, an innovative state space-based Transformer model is proposed to address the challenges of complex system prediction tasks. By integrating state space theory, the model aims to enhance the capability to capture dynamic changes in complex data, thereby improving the accuracy [...] Read more.
In this research, an innovative state space-based Transformer model is proposed to address the challenges of complex system prediction tasks. By integrating state space theory, the model aims to enhance the capability to capture dynamic changes in complex data, thereby improving the accuracy and robustness of prediction tasks. Extensive experimental validations were conducted on three representative tasks, including legal case judgment, legal case translation, and financial data analysis to assess the performance and application potential of the model. The experimental results demonstrate significant performance improvements of the proposed model over traditional Transformer models and other advanced variants such as Bidirectional Encoder Representation from Transformers (BERT) and Finsformer across all evaluated tasks. Specifically, in the task of legal case judgment, the proposed model exhibited a precision of 0.93, a recall of 0.90, and an accuracy of 0.91, significantly surpassing the traditional Transformer model (with precision of 0.78, recall of 0.73, accuracy of 0.76) and performances of other comparative models. In the task of legal case translation, the precision of the proposed model reached 0.95, with a recall of 0.91 and an accuracy of 0.93, also outperforming other models. Likewise, in the task of financial data analysis, the proposed model also demonstrated excellent performance, with a precision of 0.94, recall of 0.90, and accuracy of 0.92. The state space-based Transformer model proposed not only theoretically expands the research boundaries of deep learning models in complex system prediction but also validates its efficiency and broad application prospects through experiments. These achievements provide new insights and directions for future research and development of deep learning models, especially in tasks requiring the understanding and prediction of complex system dynamics. Full article
30 pages, 676 KiB  
Article
Two-Dimensional System of Moment Equations and Macroscopic Boundary Conditions Depending on the Velocity of Movement and the Surface Temperature of a Body Moving in Fluid
by Auzhan Sakabekov, Yerkanat Auzhani and Shinar Akimzhanova
Mathematics 2024, 12(10), 1491; https://doi.org/10.3390/math12101491 (registering DOI) - 10 May 2024
Abstract
This article is dedicated to the derivation of a two-dimensional system of moment equations depending on the velocity of movement and the surface temperature of a body submerged in fluid, and macroscopic boundary conditions for the system of moment equations approximating the Maxwell [...] Read more.
This article is dedicated to the derivation of a two-dimensional system of moment equations depending on the velocity of movement and the surface temperature of a body submerged in fluid, and macroscopic boundary conditions for the system of moment equations approximating the Maxwell microscopic boundary condition for the particle distribution function. The initial-boundary value problem for the Boltzmann equation with the Maxwell microscopic boundary condition is approximated by a corresponding problem for the system of moment equations with macroscopic boundary conditions. The number of moment equations and the number of macroscopic boundary conditions are interconnected and depend on the parity of the approximation of the system of moment equations. The setting of the initial-boundary value problem for a non-stationary, nonlinear two-dimensional system of moment equations in the first approximation with macroscopic boundary conditions is presented, and the solvability of the above-mentioned problem in the space of functions continuous in time and square-integrable in spatial variables is proven. Full article
20 pages, 1044 KiB  
Article
Innovative Design of Solid-State Hydrogen Storage and Proton Exchange Membrane Fuel Cell Coupling System with Enhanced Cold Start Control Strategy
by Jianhua Gao, Su Zhou, Lei Fan, Gang Zhang, Yongyuan Jiang, Wei Shen and Shuang Zhai
Appl. Sci. 2024, 14(10), 4068; https://doi.org/10.3390/app14104068 (registering DOI) - 10 May 2024
Abstract
This paper presents an innovative thermally coupled system architecture with a parallel coolant-heated metal hydride tank (MHT) designed to satisfy the hydrogen supply requirements of proton exchange membrane fuel cell s(PEMFCs). This design solves a problem by revolutionising the cold start capability of [...] Read more.
This paper presents an innovative thermally coupled system architecture with a parallel coolant-heated metal hydride tank (MHT) designed to satisfy the hydrogen supply requirements of proton exchange membrane fuel cell s(PEMFCs). This design solves a problem by revolutionising the cold start capability of PEMFCs at low temperatures. During the design process, LaNi5 was selected as the hydrogen storage material, with thermodynamic and kinetic properties matching the PEMFC operating conditions. Afterwards, the MHT and thermal management subsystem were customised to integrate with the 70 kW PEMFC system to ensure optimal performance. Given the limitations of conventional high-pressure gaseous hydrogen storage for cold starting, this paper provides insights into the challenges faced by the PEMFC-MH system and proposes an innovative cold start methodology that combines internal self-heating and externally assisted preheating techniques, aiming to optimise cold start time, energy consumption, and hydrogen utilisation. The results show that the PEMFC-MH system utilises the heat generated during hydrogen absorption by the MHT to preheat the PEMFC stack, and the cold start time is only 101 s, which is 59.3% shorter compared to that of the conventional method. Meanwhile, the cold start energy consumption is reduced by 62.4%, achieving a significant improvement in energy efficiency. In conclusion, this paper presents a PEMFC-MH system design that achieves significant progress in terms of time saving, energy consumption, and hydrogen utilisation. Full article
(This article belongs to the Topic Energy Storage and Conversion Systems, 2nd Volume)
11 pages, 672 KiB  
Article
On V-Geometric Ergodicity Markov Chains of the Two-Inertia Systems
by Feng-Rung Hu and Jia-Sheng Hu
Mathematics 2024, 12(10), 1492; https://doi.org/10.3390/math12101492 (registering DOI) - 10 May 2024
Abstract
This study employs the diffusion process to construct Markov chains for analyzing the common two-inertia systems used in industry. Two-inertia systems are prevalent in commonly used equipment, where the load is influenced by the coupling of external force and the drive shaft, leading [...] Read more.
This study employs the diffusion process to construct Markov chains for analyzing the common two-inertia systems used in industry. Two-inertia systems are prevalent in commonly used equipment, where the load is influenced by the coupling of external force and the drive shaft, leading to variations in the associated output states. Traditionally, the control of such systems is often guided by empirical rules. This paper examines the equilibrium distribution and convergence rate of the two-inertia system and develops a predictive model for its long-term operation. We explore the qualitative behavior of the load end at discrete time intervals. Our findings are applicable not only in control engineering, but also provide insights for small-scale models incorporating dual-system variables. Full article
(This article belongs to the Special Issue Advances of Applied Probability and Statistics)
21 pages, 4473 KiB  
Article
Advanced Integration of Machine Learning Techniques for Accurate Segmentation and Detection of Alzheimer’s Disease
by Esraa H. Ali, Sawsan Sadek, Georges Zakka El Nashef and Zaid F. Makki
Algorithms 2024, 17(5), 207; https://doi.org/10.3390/a17050207 (registering DOI) - 10 May 2024
Abstract
Alzheimer’s disease is a common type of neurodegenerative condition characterized by progressive neural deterioration. The anatomical changes associated with individuals affected by Alzheimer’s disease include the loss of tissue in various areas of the brain. Magnetic Resonance Imaging (MRI) is commonly used as [...] Read more.
Alzheimer’s disease is a common type of neurodegenerative condition characterized by progressive neural deterioration. The anatomical changes associated with individuals affected by Alzheimer’s disease include the loss of tissue in various areas of the brain. Magnetic Resonance Imaging (MRI) is commonly used as a noninvasive tool to assess the neural structure of the brain for diagnosing Alzheimer’s disease. In this study, an integrated Improved Fuzzy C-means method with improved watershed segmentation was employed to segment the brain tissue components affected by this disease. These segmented features were fed into a hybrid technique for classification. Specifically, a hybrid Convolutional Neural Network–Long Short-Term Memory classifier with 14 layers was developed in this study. The evaluation results revealed that the proposed method achieved an accuracy of 98.13% in classifying segmented brain images according to different disease severities. Full article
(This article belongs to the Section Algorithms for Multidisciplinary Applications)
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16 pages, 7207 KiB  
Article
Impact of Plant Extract Phytochemicals on the Synthesis of Silver Nanoparticles
by Oksana Velgosova, Silvia Dolinská, Helena Podolská, Lívia Mačák and Elena Čižmárová
Materials 2024, 17(10), 2252; https://doi.org/10.3390/ma17102252 (registering DOI) - 10 May 2024
Abstract
This work aims to analyze the influence of selected plants on the synthesis of silver nanoparticles (AgNPs). Six plants were chosen for the experiment, from which extracts were prepared: maclura fruit, spruce and ginkgo needles, green algae (Ch. kessleri), and mushrooms, [...] Read more.
This work aims to analyze the influence of selected plants on the synthesis of silver nanoparticles (AgNPs). Six plants were chosen for the experiment, from which extracts were prepared: maclura fruit, spruce and ginkgo needles, green algae (Ch. kessleri), and mushrooms, namely Collybia nuda, and Macrolepiota procera. The composition of the extracts and colloids after preparation of the nanoparticles was analyzed using FTIR analysis. The composition of the extracts affected not only the rate of the synthesis but also the shape of the nanoparticles. TEM analysis confirmed the synthesis of mainly spherical nanoparticles (size range: 10–25 nm). However, triangular prisms and polyhedral nanoparticles synthesized by the extracts containing mainly flavonoids, terpenes, and phenols (the main compounds of resins) were also confirmed. EDS analysis was used to analyze the composition of the nanoparticles. It was proven that by choosing the right plant extract and using the appropriate technology with extract treatment, it is possible to prepare nanoparticles of different shapes. Full article
(This article belongs to the Special Issue Physical Synthesis, Properties and Applications of Nanoparticles)
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18 pages, 907 KiB  
Article
Multi-Objective Optimization of Tribological Characteristics for Aluminum Composite Using Taguchi Grey and TOPSIS Approaches
by Sandra Gajević, Ana Marković, Saša Milojević, Aleksandar Ašonja, Lozica Ivanović and Blaža Stojanović
Lubricants 2024, 12(5), 171; https://doi.org/10.3390/lubricants12050171 (registering DOI) - 10 May 2024
Abstract
In this study, a multi-objective optimization regarding the tribological characteristics of the hybrid composite with a base material of aluminum alloy A356 as a constituent, reinforced with a 10 wt.% of silicon carbide (SiC), size 39 µm, and 1, 3, and 5 wt.% [...] Read more.
In this study, a multi-objective optimization regarding the tribological characteristics of the hybrid composite with a base material of aluminum alloy A356 as a constituent, reinforced with a 10 wt.% of silicon carbide (SiC), size 39 µm, and 1, 3, and 5 wt.% graphite (Gr), size 35 µm, was performed using the Taguchi method, gray relational analysis (GRA), and Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) decision-making methods. Tribological tests were carried out on a “block on disc” type tribometer with lubrication. Load, sliding speed, and graphite mass concentration were analyzed as input parameters. As output parameters, wear rate and coefficient of friction were calculated. An analysis of variance (ANOVA) was conducted to identify all parameters that have a significant influence on the output multi-response. It was found that the normal load has the highest influence of 41.86%, followed by sliding speed at 32.48% and graphite addition at 18.47%, on the tribological characteristics of composites. Multi-objective optimization determined that the minimal wear rate and coefficient of friction are obtained when the load is 40 N, the sliding speed is 1 m/s, and the composite contains 3 wt.% Gr. The optimal combination of parameters achieved by GRA was also confirmed by the TOPSIS method, which indicates that both methods can be used with high reliability to optimize the tribological characteristics. The analysis of worn surfaces using scanning electron microscopy revealed adhesive and delamination wear as dominant mechanisms. Full article
12 pages, 512 KiB  
Article
Genetic Diversity and Genome-Wide Association Analysis of the Hulled/Naked Trait in a Barley Collection from Shanghai Agricultural Gene Bank
by Zhiwei Chen, Zhenzhu Guo, Luli Li, Nigel G. Halford, Guimei Guo, Shuwei Zhang, Yingjie Zong, Shiseng Liu, Chenghong Liu and Longhua Zhou
Int. J. Mol. Sci. 2024, 25(10), 5217; https://doi.org/10.3390/ijms25105217 (registering DOI) - 10 May 2024
Abstract
Barley is one of the most important cereal crops in the world, and its value as a food is constantly being revealed, so the research into and the use of barley germplasm are very important for global food security. Although a large number [...] Read more.
Barley is one of the most important cereal crops in the world, and its value as a food is constantly being revealed, so the research into and the use of barley germplasm are very important for global food security. Although a large number of barley germplasm samples have been collected globally, their specific genetic compositions are not well understood, and in many cases their origins are even disputed. In this study, 183 barley germplasm samples from the Shanghai Agricultural Gene Bank were genotyped using genotyping-by-sequencing (GBS) technology, SNPs were identified and their genetic parameters were estimated, principal component analysis (PCA) was preformed, and the phylogenetic tree and population structure of the samples were also analyzed. In addition, a genome-wide association study (GWAS) was carried out for the hulled/naked grain trait, and a KASP marker was developed using an associated SNP. The results showed that a total of 181,906 SNPs were identified, and these barley germplasm samples could be roughly divided into three categories according to the phylogenetic analysis, which was generally consistent with the classification of the traits of row type and hulled/naked grain. Population structure analysis showed that the whole barley population could be divided into four sub-populations (SPs), the main difference from previous classifications being that the two-rowed and the hulled genotypes were sub-divided into two SPs. The GWAS analysis of the hulled/naked trait showed that many associated loci were unrelated to the Nud/nud locus, indicating that there might be new loci controlling the trait. A KASP marker was developed for one exon-type SNP on chromosome 7. Genotyping based on the KASP assay was consistent with that based on SNPs, indicating that the gene of this locus might be associated with the hulled/naked trait. The above work not only lays a good foundation for the future utilization of this barley germplasm population but it provides new loci and candidate genes for the hulled/naked trait. Full article
(This article belongs to the Collection Advances in Molecular Plant Sciences)
11 pages, 733 KiB  
Article
High Tartronic Acid Content Germplasms Screening of Cucumber and Its Response to Exogenous Agents
by Zhongren Zhang, Yixin Qu, Ruijia Wang, Yaru Wang, Songlin Yang, Lei Sun, Sen Li, Yiming Gao, Yuming Dong, Xingwang Liu and Huazhong Ren
Foods 2024, 13(10), 1484; https://doi.org/10.3390/foods13101484 (registering DOI) - 10 May 2024
Abstract
Tartronic acid is known for its potential to inhibit sugar-to-lipid conversion in the human body, leading to weight loss and fat reduction. This compound is predominantly found in cucumbers and other cucurbit crops. Therefore, cultivating cucumbers with high tartronic acid content holds significant [...] Read more.
Tartronic acid is known for its potential to inhibit sugar-to-lipid conversion in the human body, leading to weight loss and fat reduction. This compound is predominantly found in cucumbers and other cucurbit crops. Therefore, cultivating cucumbers with high tartronic acid content holds significant health implications. In this study, we assessed the tartronic acid content in 52 cucumber germplasms with favorable overall traits and identified 8 cucumber germplasms with elevated tartronic acid levels. Our investigation into factors influencing cucumber tartronic acid revealed a decrease in content with fruit development from the day of flowering. Furthermore, tartronic acid content was higher in early-harvested fruits compared to late-harvested ones, with the rear part of the fruit exhibiting significantly higher content than other parts. Foliar spraying of microbial agents increased tartronic acid content by 84.4%. This study provides valuable resources for breeding high tartronic acid cucumbers and offers practical insights for optimizing cucumber production practices. Full article
(This article belongs to the Section Plant Foods)
22 pages, 15441 KiB  
Article
Hardness Distribution and Growth Behavior of Micro-Arc Oxide Ceramic Film with Positive and Negative Pulse Coordination
by Haomin Li, Shiqin Kong, Zhiming Liu, Zhenxing Wang and Yingsan Geng
Nanomaterials 2024, 14(10), 842; https://doi.org/10.3390/nano14100842 (registering DOI) - 10 May 2024
Abstract
Micro-arc oxidation (MAO) is a promising technology for enhancing the wear resistance of engine cylinders by growing a high hardness alumina ceramic film on the surface of light aluminum engine cylinders. However, the positive and negative pulse coordination, voltage characteristic signal, hardness distribution [...] Read more.
Micro-arc oxidation (MAO) is a promising technology for enhancing the wear resistance of engine cylinders by growing a high hardness alumina ceramic film on the surface of light aluminum engine cylinders. However, the positive and negative pulse coordination, voltage characteristic signal, hardness distribution characteristics of the ceramic film, and their internal mechanism during the growth process are still unclear. This paper investigates the synergistic effect mechanism of cathodic and anodic current on the growth behaviour of alumina, dynamic voltage signal, and hardness distribution of micro-arc oxidation film. Ceramic film samples were fabricated under various conditions, including current densities of 10, 12, 14, and 16 A/dm2, and current density ratios of cathode and anode of 1.1, 1.2, and 1.3, respectively. Based on the observed characteristics of the process voltage curve and the spark signal changes, the growth of the ceramic film can be divided into five stages. The influence of positive and negative current density parameters on the segmented growth process of the ceramic film is mainly reflected in the transition time, voltage variation rate, and the voltage value of different growth stages. Enhancing the cathode pulse effect or increasing the current density level can effectively shorten the transition time and accelerate the voltage drop rate. The microhardness of the ceramic film cross-section presents a discontinuous soft-hard-soft regional distribution. Multiple thermal cycles lead to a gradient differentiation of the Al2O3 crystal phase transition ratio along the thickness direction of the layer. The layer grown on the outer surface of the initial substrate exhibits the highest hardness, with a small gradient change in hardness, forming a high hardness zone approximately 20–30 μm wide. This high hardness zone extends to both sides, with hardness decreasing rapidly. Full article
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16 pages, 862 KiB  
Article
Mass Spectrometric Analysis of Purine Intermediary Metabolism Indicates Cyanide Induces Purine Catabolism in Rabbits
by Jordan Morningstar, Jangwoen Lee, Sari Mahon, Matthew Brenner and Anjali K. Nath
Metabolites 2024, 14(5), 279; https://doi.org/10.3390/metabo14050279 (registering DOI) - 10 May 2024
Abstract
Purines are the building blocks of DNA/RNA, energy substrates, and cofactors. Purine metabolites, including ATP, GTP, NADH, and coenzyme A, are essential molecules in diverse biological processes such as energy metabolism, signal transduction, and enzyme activity. When purine levels increase, excess purines are [...] Read more.
Purines are the building blocks of DNA/RNA, energy substrates, and cofactors. Purine metabolites, including ATP, GTP, NADH, and coenzyme A, are essential molecules in diverse biological processes such as energy metabolism, signal transduction, and enzyme activity. When purine levels increase, excess purines are either recycled to synthesize purine metabolites or catabolized to the end product uric acid. Purine catabolism increases during states of low oxygen tension (hypoxia and ischemia), but this metabolic pathway is incompletely understood in the context of histotoxic hypoxia (i.e., inhibition of oxygen utilization despite normal oxygen tension). In rabbits exposed to cyanide—a classical histotoxic hypoxia agent—we demonstrated significant increases in several concordant metabolites in the purine catabolic pathway (including plasma levels of uric acid, xanthosine, xanthine, hypoxanthine, and inosine) via mass spectrometry-based metabolite profiling. Pharmacological inhibition of the purine catabolic pathway with oxypurinol mitigated the deleterious effects of cyanide on skeletal muscle cytochrome c oxidase redox state, measured by non-invasive diffuse optical spectroscopy. Finally, plasma uric acid levels correlated strongly with those of lactic acid, an established clinical biomarker of cyanide exposure, in addition to a tissue biomarker of cyanide exposure (skeletal muscle cytochrome c oxidase redox state). Cumulatively, these findings not only shed light on the in vivo role(s) of cyanide but also have implications in the field of medical countermeasure (MCM) development. Full article
(This article belongs to the Special Issue Preclinical and Clinical Application of Metabolomics in Medicine)
18 pages, 544 KiB  
Article
Unveiling the Antioxidant Potential of Halophyte Plants and Seaweeds for Health Applications
by Inês João Ferreira, Ana Rita C. Duarte, Mário Diniz and Ricardo Salgado
Oxygen 2024, 4(2), 163-180; https://doi.org/10.3390/oxygen4020011 (registering DOI) - 10 May 2024
Abstract
Halophyte plants and seaweed are described in the literature as rich sources of antioxidant compounds that can be used in the pharmaceutical and food industries. In this work, we studied the antioxidant composition of five species of halophytic plants (Suaeda vera Forssk, [...] Read more.
Halophyte plants and seaweed are described in the literature as rich sources of antioxidant compounds that can be used in the pharmaceutical and food industries. In this work, we studied the antioxidant composition of five species of halophytic plants (Suaeda vera Forssk, Portulaca oleracea L., Inula crithmoides L., Salicornia ramosissima (Hook.f.) J. Woods and Sarcocornia perennis (Mill.) A.J.Scott) and three seaweeds (Gracilaria gracilis (Stackhouse) Steentoft, L.Irvine and Farnham, Fucus spiralis L. and Ulva rigida C. Agardh) collected in Sado Estuary, Portugal. In the case of the plants, different parts of the plant were also assessed. Various extraction procedures were also performed to understand which methods were most suitable for extracting the various antioxidant compounds. Therefore, the aim of this study was to characterize the antioxidant compounds in halophytes and seaweed using various methods (ABTS, DPPH and FRAP), as well as the phenolic (TPC) and flavonoid (TFC) contents in the different extracts obtained. The amount of soluble protein in each extract was also determined. The results show that methanolic extracts generally have a higher antioxidant capacity, while the highest soluble protein content was observed in aqueous extracts. The seaweed Fucus Spiralis showed the highest antioxidant content, while in halophytic plants the highest antioxidant content was detected in the leaves. In general, this work confirms the potential of halophytes and seaweed as sources of antioxidant compounds for use in the food and pharmaceutical industries. Full article
18 pages, 564 KiB  
Article
Effects of Soils on Environmental Stability of Spent Mg-Based and Ca-Based Adsorbents Containing Arsenite
by Hajime Sugita, Kazuya Morimoto, Takeshi Saito and Junko Hara
Sustainability 2024, 16(10), 4008; https://doi.org/10.3390/su16104008 (registering DOI) - 10 May 2024
Abstract
Spent adsorbents used in As removal treatment may re-leach As. In this study, the effects of soil on spent Mg-based and Ca-based adsorbents were investigated. The spent adsorbents containing arsenite (As(III)) were prepared by adsorbing As(III) on MgO, Mg(OH)2, CaO, and [...] Read more.
Spent adsorbents used in As removal treatment may re-leach As. In this study, the effects of soil on spent Mg-based and Ca-based adsorbents were investigated. The spent adsorbents containing arsenite (As(III)) were prepared by adsorbing As(III) on MgO, Mg(OH)2, CaO, and Ca(OH)2 powder reagents. Kuroboku soil (Ku), yellow-brown forest soil (YF), Kanuma soil (Ka), river sand (RS), and mountain sand (MS) were used as soil samples. The As leaching ratio was examined in coexistence with soil via shaking tests, and the results were compared with those of a previous study on adsorbents containing arsenate (As(V)). The environmental stability of the spent adsorbents was found to vary greatly depending on the combination of the As valence, adsorbent type, and soil type. However, regardless of the adsorbent or soil type, the spent adsorbents containing As(III) were more likely to leach As than those containing As(V). Additionally, the As leaching ratio was generally lower in Ku and YF and higher in Ka, RS, and MS. For environmentally friendly and sustainable As removal treatment, disposal, and management, the selection of MgO as the adsorbent and treatment involving the oxidation treatment of As(III) to As(V) before adsorbing As onto adsorbents are recommended. Full article
(This article belongs to the Section Pollution Prevention, Mitigation and Sustainability)
29 pages, 2092 KiB  
Article
Challenges of Robust RNAi-Mediated Gene Silencing in Aedes Mosquitoes
by Lucas Henrique Figueiredo Prates, Jakob Fiebig, Henrik Schlosser, Eleni Liapi, Tanja Rehling, Célia Lutrat, Jeremy Bouyer, Qiang Sun, Han Wen, Zhiyong Xi, Marc F. Schetelig and Irina Häcker
Int. J. Mol. Sci. 2024, 25(10), 5218; https://doi.org/10.3390/ijms25105218 (registering DOI) - 10 May 2024
Abstract
In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes Aedes aegypti and Aedes albopictus, a pivotal approach for genetic analysis and vector control. Despite RNAi’s potential for species-specific gene [...] Read more.
In this study, we report the complexities and challenges associated with achieving robust RNA interference (RNAi)-mediated gene knockdown in the mosquitoes Aedes aegypti and Aedes albopictus, a pivotal approach for genetic analysis and vector control. Despite RNAi’s potential for species-specific gene targeting, our independent efforts to establish oral delivery of RNAi for identifying genes critical for mosquito development and fitness encountered significant challenges, failing to reproduce previously reported potent RNAi effects. We independently evaluated a range of RNAi-inducing molecules (siRNAs, shRNAs, and dsRNAs) and administration methods (oral delivery, immersion, and microinjection) in three different laboratories. We also tested various mosquito strains and utilized microorganisms for RNA delivery. Our results reveal a pronounced inconsistency in RNAi efficacy, characterized by minimal effects on larval survival and gene expression levels in most instances despite strong published effects for the tested targets. One or multiple factors, including RNase activity in the gut, the cellular internalization and processing of RNA molecules, and the systemic dissemination of the RNAi signal, could be involved in this variability, all of which are barely understood in mosquitoes. The challenges identified in this study highlight the necessity for additional research into the underlying mechanisms of mosquito RNAi to develop more robust RNAi-based methodologies. Our findings emphasize the intricacies of RNAi application in mosquitoes, which present a substantial barrier to its utilization in genetic control strategies. Full article
15 pages, 804 KiB  
Article
Osmolality and Tonicity of Isotonic Beverages
by Tjaša Skarlovnik, Andraž Lamut, Gregor Hostnik, Boris Gole and Urban Bren
Foods 2024, 13(10), 1483; https://doi.org/10.3390/foods13101483 (registering DOI) - 10 May 2024
Abstract
This study aimed to measure and compare the osmolality and tonicity of isotonic beverages that can be bought on the Slovenian market. The main goal was to examine how good is the agreement between the measured osmolalities of the beverages and the requirements [...] Read more.
This study aimed to measure and compare the osmolality and tonicity of isotonic beverages that can be bought on the Slovenian market. The main goal was to examine how good is the agreement between the measured osmolalities of the beverages and the requirements for isotonic beverages set up by EFSA. Osmolalities were measured with an osmometer using the freezing point depression method. Afterwards, two complementary methods for the observation of tonicity were developed. Erythrocytes were exposed to standard NaCl solutions of different osmolalities to observe their influence on the volume and shape of cells following the turbidity of the solution and the morphology of erythrocytes. These two methods enabled us to determine whether standard solutions were hypo-, iso-, or hypertonic. In this way, we found that the osmolality of 12 out of the 18 investigated isotonic beverages was in the range of 270–330 mOsm/kg, as required by EFSA. However, six samples did not meet this criterion and should therefore not have the label “isotonic” or be described as such. The measurements of turbidity of solutions indicated that most isotonic beverages exhibit a lower tonicity than standard NaCl solutions of identical osmolality. However, examination of the erythrocytes in isotonic beverages showed that the measurements were additionally complicated by the low pH values of these beverages. Finally, by demonstrating how different components of isotonic beverages pass through the erythrocyte membranes, we found that even isoosmolal beverages are often not isotonic, as the concentration of actively transported sugars in these beverages is relatively high. Full article
(This article belongs to the Section Food Quality and Safety)
13 pages, 474 KiB  
Article
Rising Trends in Metabolically Healthy Obesity in Cancer Patients and Its Impact on Cardiovascular Events: Insights from A Contemporary Nationwide Analysis in the USA (2016–2020)
by Vamsikalyan Borra, Akhil Jain, Nithya Borra, Lakshmi Prasanna Vaishnavi Kattamuri, Sidhartha Gautam Senapati, Naga Vamsi Krishna Machineni, Sindhuja Kukkala, Karthikeya Ramasahayam, Kesar Prajapati, Ankit Vyas and Rupak Desai
J. Clin. Med. 2024, 13(10), 2820; https://doi.org/10.3390/jcm13102820 (registering DOI) - 10 May 2024
Abstract
Obesity or overweight raises the risk of developing 13 types of cancer, representing 40% of all cancers diagnosed in the United States annually. Given the ongoing debate surrounding the impact of metabolically healthy obesity (MHO) on cardiovascular outcomes, it is crucial to comprehend [...] Read more.
Obesity or overweight raises the risk of developing 13 types of cancer, representing 40% of all cancers diagnosed in the United States annually. Given the ongoing debate surrounding the impact of metabolically healthy obesity (MHO) on cardiovascular outcomes, it is crucial to comprehend the incidence of Major Adverse Cardiovascular and Cerebrovascular Events (MACCEs) and the influence of MHO on these outcomes in cancer patients. Methods: Data of hospitalized cancer patients with and without obesity were analyzed from the National Inpatient Sample 2016–2020. Metabolically healthy patients were identified by excluding diabetes, hypertension, and hyperlipidemia using Elixhauser comorbidity software, v.2022.1. After that, we performed a multivariable regression analysis for in-hospital MACCEs and other individual outcomes. Results: We identified 3,111,824 cancer-related hospitalizations between 2016 and 2020. The MHO cohort had 199,580 patients (6.4%), whereas the MHnO (metabolically healthy non-obese) cohort had 2,912,244 patients (93.6%). The MHO cohort had a higher proportion of females, Blacks, and Hispanics. Outcomes including in-hospital MACCEs (7.9% vs. 9.5%; p < 0.001), all-cause mortality (6.1% vs. 7.5%; p < 0.001), and acute myocardial infarction (AMI) (1.5% vs. 1.6%; p < 0.001) were lower in the MHO cohort compared to the MHnO cohort. Upon adjusting for the baseline characteristics, the MHO group had lower odds of in-hospital MACCEs [adjusted odds ratio (AOR) = 0.93, 95% CI (0.90–0.97), p < 0.001], all-cause mortality [AOR = 0.91, 95% CI (0.87–0.94); p < 0.001], and acute ischemic stroke (AIS) [AOR = 0.76, 95% CI (0.69–0.84); p < 0.001], whereas there were higher odds of acute myocardial infarction (AMI) [AOR = 1.08, 95% CI (1.01–1.16); p < 0.001] and cardiac arrest (CA) [AOR = 1.26, 95% CI (1.01–1.57); p = 0.045] in the MHO cohort compared to the MHnO cohort. Conclusions: Hospitalized cancer patients with MHO exhibited a lower prevalence of in-hospital MACCEs than those with MHnO. Additional prospective studies and randomized clinical trials are imperative to validate these findings, particularly in stratifying MHO across various cancer types and their corresponding risks of in-hospital MACCEs. Full article
(This article belongs to the Section Cardiovascular Medicine)
18 pages, 3603 KiB  
Article
Modulation of Tropane Alkaloids’ Biosynthesis and Gene Expression by Methyl Jasmonate in Datura stramonium L.: A Comparative Analysis of Scopolamine, Atropine, and Hyoscyamine Accumulation
by Arash Rasi, Manijeh Sabokdast, Mohammad Reza Naghavi, Parisa Jariani and Beáta Dedičová
Life 2024, 14(5), 618; https://doi.org/10.3390/life14050618 (registering DOI) - 10 May 2024
Abstract
Scopolamine and atropine are two medicinal alkaloids derived from Datura stramonium L. with anticholinergic properties. This study explored how methyl jasmonate (MJ), a plant growth regulator, affects the biosynthesis and accumulation of these alkaloids in different plant tissues. The expression levels of putrescine [...] Read more.
Scopolamine and atropine are two medicinal alkaloids derived from Datura stramonium L. with anticholinergic properties. This study explored how methyl jasmonate (MJ), a plant growth regulator, affects the biosynthesis and accumulation of these alkaloids in different plant tissues. The expression levels of putrescine N-methyltransferase (PMT), tropinone reductase I (TR1), and hyoscyamine 6β-hydroxylase (h6h), three critical enzymes in the biosynthetic pathway, were also analyzed. The results indicated that MJ at 150 µM increased the production of scopolamine and atropine in both leaves and roots, while MJ at 300 µM had an adverse effect. Furthermore, MJ enhanced the expression of PMT, TR1, and h6h genes in the roots, the primary site of alkaloid synthesis, but not in the leaves, the primary site of alkaloid storage. These results imply that MJ can be applied to regulate the biosynthesis and accumulation of scopolamine and atropine in D. stramonium, thereby improving their production efficiency. Full article
(This article belongs to the Section Genetics and Genomics)
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16 pages, 622 KiB  
Article
Effects of Black Soldier Fly (Hermetia illucens L., BSF) Larvae Addition on In Vitro Fermentation Parameters of Goat Diets
by Shengyong Lu, Shengchang Chen, Siwaporn Paengkoum, Nittaya Taethaisong, Weerada Meethip, Jariya Surakhunthod, Qingfeng Wang, Sorasak Thongpea and Pramote Paengkoum
Insects 2024, 15(5), 343; https://doi.org/10.3390/insects15050343 (registering DOI) - 10 May 2024
Abstract
The purpose of this experiment was to evaluate the effects of different levels of BSF on rumen in vitro fermentation gas production, methane (CH4) production, ammonia nitrogen (NH3-N), and volatile fatty acids (VFAs). The experiment comprised four treatments, each [...] Read more.
The purpose of this experiment was to evaluate the effects of different levels of BSF on rumen in vitro fermentation gas production, methane (CH4) production, ammonia nitrogen (NH3-N), and volatile fatty acids (VFAs). The experiment comprised four treatments, each with five replicates. The control group contained no BSF (BSF0), and the treatment groups contained 5% (BSF5), 10% (BSF10), and 15% (BSF15) BSF, respectively. Results showed that at 3 h, 9 h, and 24 h, gas production in BSF5 and BSF10 was significantly higher than in BSF0 and BSF15 (p < 0.05). Gas production in BSF5 and BSF10 was higher than in BSF0, while gas production in BSF15 was lower than in BSF0. At 6 h and 12 h, CH4 emission in BSF15 was significantly lower than in the other three groups (p < 0.05). There were no differences in the pH of in vitro fermentation after BSF addition (p > 0.05). At 3 h, NH3-N levels in BSF10 and BSF15 were significantly higher than in BSF0 and BSF5 (p < 0.05). At 6 h, NH3-N levels in BSF5 and BSF10 were significantly higher than in BSF0 and BSF15 (p < 0.05). Acetic acid, propionic acid, butyric acid, and total VFAs in BSF0, BSF5, and BSF10 were significantly higher than in BSF15 (p < 0.05). In conclusion, gas production, CH4 emission, NH3-N, acetic acid, propionic acid, butyric acid, and VFAs were highest in BSF5 and BSF10 and lowest in BSF15. Full article
(This article belongs to the Section Role of Insects in Human Society)
24 pages, 4287 KiB  
Article
Identification of an Immunodominant B-Cell Epitope in African Swine Fever Virus p30 Protein and Evidence of p30 Antibody-Mediated Antibody Dependent Cellular Cytotoxicity
by Jessica C. G. Noll, Ruchi Rani, Salman L. Butt, Maureen Hoch Vieira Fernandes, Gabriela Mansano do Nascimento, Mathias Martins, Leonardo C. Caserta, Lina Covaleda and Diego G. Diel
Viruses 2024, 16(5), 758; https://doi.org/10.3390/v16050758 (registering DOI) - 10 May 2024
Abstract
African Swine Fever Virus (ASFV) is a large dsDNA virus that encodes at least 150 proteins. The complexity of ASFV and lack of knowledge of effector immune functions and protective antigens have hindered the development of safe and effective ASF vaccines. In this [...] Read more.
African Swine Fever Virus (ASFV) is a large dsDNA virus that encodes at least 150 proteins. The complexity of ASFV and lack of knowledge of effector immune functions and protective antigens have hindered the development of safe and effective ASF vaccines. In this study, we constructed four Orf virus recombinant vectors expressing individual ASFV genes B602L, -CP204L, E184L, and -I73R (ORFVΔ121-ASFV-B602L, -CP204L, -E184L, and -I73R). All recombinant viruses expressed the heterologous ASFV proteins in vitro. We then evaluated the immunogenicity of the recombinants by immunizing four-week-old piglets. In two independent animal studies, we observed high antibody titers against ASFV p30, encoded by CP204L gene. Using Pepscan ELISA, we identified a linear B-cell epitope of 12 amino acids in length (Peptide 15) located in an exposed loop region of p30 as an immunodominant ASFV epitope. Additionally, antibodies elicited against ASFV p30 presented antibody-dependent cellular cytotoxicity (ADCC) activity. These results underscore the role of p30 on antibody responses elicited against ASFV and highlight an important functional epitope that contributes to p30-specific antibody responses. Full article
(This article belongs to the Section Viral Immunology, Vaccines, and Antivirals)
15 pages, 949 KiB  
Article
SARS-CoV-2-Induced Type I Interferon Signaling Dysregulation in Olfactory Networks Implications for Alzheimer’s Disease
by George D. Vavougios, Theodoros Mavridis, Triantafyllos Doskas, Olga Papaggeli, Pelagia Foka and Georgios Hadjigeorgiou
Curr. Issues Mol. Biol. 2024, 46(5), 4565-4579; https://doi.org/10.3390/cimb46050277 (registering DOI) - 10 May 2024
Abstract
Type I interferon signaling (IFN-I) perturbations are major drivers of COVID-19. Dysregulated IFN-I in the brain, however, has been linked to both reduced cognitive resilience and neurodegenerative diseases such as Alzheimer’s. Previous works from our group have proposed a model where peripheral induction [...] Read more.
Type I interferon signaling (IFN-I) perturbations are major drivers of COVID-19. Dysregulated IFN-I in the brain, however, has been linked to both reduced cognitive resilience and neurodegenerative diseases such as Alzheimer’s. Previous works from our group have proposed a model where peripheral induction of IFN-I may be relayed to the CNS, even in the absence of fulminant infection. The aim of our study was to identify significantly enriched IFN-I signatures and genes along the transolfactory route, utilizing published datasets of the nasal mucosa and olfactory bulb amygdala transcriptomes of COVID-19 patients. We furthermore sought to identify these IFN-I signature gene networks associated with Alzheimer’s disease pathology and risk. Gene expression data involving the nasal epithelium, olfactory bulb, and amygdala of COVID-19 patients and transcriptomic data from Alzheimer’s disease patients were scrutinized for enriched Type I interferon pathways. Gene set enrichment analyses and gene–Venn approaches were used to determine genes in IFN-I enriched signatures. The Agora web resource was used to identify genes in IFN-I signatures associated with Alzheimer’s disease risk based on its aggregated multi-omic data. For all analyses, false discovery rates (FDR) <0.05 were considered statistically significant. Pathways associated with type I interferon signaling were found in all samples tested. Each type I interferon signature was enriched by IFITM and OAS family genes. A 14-gene signature was associated with COVID-19 CNS and the response to Alzheimer’s disease pathology, whereas nine genes were associated with increased risk for Alzheimer’s disease based on Agora. Our study provides further support to a type I interferon signaling dysregulation along the extended olfactory network as reconstructed herein, ranging from the nasal epithelium and extending to the amygdala. We furthermore identify the 14 genes implicated in this dysregulated pathway with Alzheimer’s disease pathology, among which HLA-C, HLA-B, HLA-A, PSMB8, IFITM3, HLA-E, IFITM1, OAS2, and MX1 as genes with associated conferring increased risk for the latter. Further research into its druggability by IFNb therapeutics may be warranted. Full article
(This article belongs to the Special Issue Advanced Research in Neuroinflammation)
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