The 2023 MDPI Annual Report has
been released!
 
18 pages, 967 KiB  
Review
Non-Invasive Retinal Vessel Analysis as a Predictor for Cardiovascular Disease
by Raluca Eugenia Iorga, Damiana Costin, Răzvana Sorina Munteanu-Dănulescu, Elena Rezuș and Andreea Dana Moraru
J. Pers. Med. 2024, 14(5), 501; https://doi.org/10.3390/jpm14050501 - 9 May 2024
Abstract
Cardiovascular disease (CVD) is the most frequent cause of death worldwide. The alterations in the microcirculation may predict the cardiovascular mortality. The retinal vasculature can be used as a model to study vascular alterations associated with cardiovascular disease. In order to quantify microvascular [...] Read more.
Cardiovascular disease (CVD) is the most frequent cause of death worldwide. The alterations in the microcirculation may predict the cardiovascular mortality. The retinal vasculature can be used as a model to study vascular alterations associated with cardiovascular disease. In order to quantify microvascular changes in a non-invasive way, fundus images can be taken and analysed. The central retinal arteriolar (CRAE), the venular (CRVE) diameter and the arteriolar-to-venular diameter ratio (AVR) can be used as biomarkers to predict the cardiovascular mortality. A narrower CRAE, wider CRVE and a lower AVR have been associated with increased cardiovascular events. Dynamic retinal vessel analysis (DRVA) allows the quantification of retinal changes using digital image sequences in response to visual stimulation with flicker light. This article is not just a review of the current literature, it also aims to discuss the methodological benefits and to identify research gaps. It highlights the potential use of microvascular biomarkers for screening and treatment monitoring of cardiovascular disease. Artificial intelligence (AI), such as Quantitative Analysis of Retinal vessel Topology and size (QUARTZ), and SIVA–deep learning system (SIVA-DLS), seems efficient in extracting information from fundus photographs and has the advantage of increasing diagnosis accuracy and improving patient care by complementing the role of physicians. Retinal vascular imaging using AI may help identify the cardiovascular risk, and is an important tool in primary cardiovascular disease prevention. Further research should explore the potential clinical application of retinal microvascular biomarkers, in order to assess systemic vascular health status, and to predict cardiovascular events. Full article
(This article belongs to the Special Issue New Advances in Diagnostic and Surgical Treatment of Ocular Diseases)
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15 pages, 1959 KiB  
Article
VEEV TC-83 Triggers Dysregulation of the Tryptophan–Kynurenine Pathway in the Central Nervous System That Correlates with Cognitive Impairment in Tg2576 Mice
by Chanida Fongsaran, Kelly T. Dineley, Slobodan Paessler and Irma E. Cisneros
Pathogens 2024, 13(5), 397; https://doi.org/10.3390/pathogens13050397 - 9 May 2024
Abstract
Neurodegenerative diseases are chronic conditions affecting the central nervous system (CNS). Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid beta in the limbic and cortical brain regions. AD is presumed to result from genetic abnormalities or environmental factors, [...] Read more.
Neurodegenerative diseases are chronic conditions affecting the central nervous system (CNS). Alzheimer’s disease (AD) is a neurodegenerative disorder characterized by the accumulation of amyloid beta in the limbic and cortical brain regions. AD is presumed to result from genetic abnormalities or environmental factors, including viral infections, which may have deleterious, long-term effects. In this study, we demonstrate that the Venezuelan equine encephalitis virus (VEEV) commonly induces neurodegeneration and long-term neurological or cognitive sequelae. Notably, the effects of VEEV infection can persistently influence gene expression in the mouse brain, suggesting a potential link between the observed neurodegenerative outcomes and long-term alterations in gene expression. Additionally, we show that alphavirus encephalitis exacerbates the neuropathological profile of AD through crosstalk between inflammatory and kynurenine pathways, generating a range of metabolites with potent effects. Using a mouse model for β-amyloidosis, Tg2576 mice, we found that cognitive deficits and brain pathology were more severe in Tg2576 mice infected with VEEV TC-83 compared to mock-infected controls. Thus, during immune activation, the kynurenine pathway plays a more active role in the VEEV TC-83-infected cells, leading to increases in the abundance of transcripts related to the kynurenine pathway of tryptophan metabolism. This pathway generates several metabolites with potent effects on neurotransmitter systems as well as on inflammation, as observed in VEEV TC-83-infected animals. Full article
(This article belongs to the Special Issue Neuropathogenesis of Arboviruses)
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14 pages, 1122 KiB  
Article
Feeling the Stress: Salivary Cortisol Responses of Softball Umpires during National Championships
by Ronald J. Houison, Andrea Lamont-Mills, Michael Kotiw and Peter C. Terry
Sports 2024, 12(5), 128; https://doi.org/10.3390/sports12050128 - 9 May 2024
Abstract
Stress research in sports tends to focus on athletes, with sports officials typically being overlooked. In the current study, baseline, pre-game, and post-game cortisol levels among a sample of softball umpires were measured to assess the pattern of stress responses and determine if [...] Read more.
Stress research in sports tends to focus on athletes, with sports officials typically being overlooked. In the current study, baseline, pre-game, and post-game cortisol levels among a sample of softball umpires were measured to assess the pattern of stress responses and determine if umpire performance (pass/fail) and position on the diamond (plate/field) could be predicted from cortisol levels. Nine male and four female participants aged 25–68 years (N = 13, M = 47.06 ± 15.65 years) each provided saliva samples on multiple occasions prior to and after officiating games at two Australian National Softball Championships. Data from 65 games were analysed. Performance was assessed using Softball Australia’s official umpire assessment tool. Cortisol levels increased significantly from baseline to pre-game (p < 0.001, d = −0.69) and declined significantly from pre-game to post-game (p < 0.001, d = 0.47). Umpiring performances were correctly classified as pass or fail from baseline and pre-game cortisol levels in 61.5% of cases and umpire position on the diamond from pre-game cortisol in 63.1% of cases. Findings suggest that stress management strategies should be recommended to softball umpires for performance enhancement and to safeguard their mental health. Full article
(This article belongs to the Special Issue Advances in Sport Psychology)
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14 pages, 3172 KiB  
Article
A Warm Welcome to the Alps—The Northward Expansion of Trithemis annulata (Odonata, Libellulidae) in Italy
by Gianandrea La Porta and Sönke Hardersen
Insects 2024, 15(5), 340; https://doi.org/10.3390/insects15050340 - 9 May 2024
Abstract
Climate warming has already influenced the distribution, community composition, and phenology of European Odonata. Trithemis annulata had been confined to the southern regions of Italy for over 150 years. In only four decades, it has expanded its range and has recently been observed [...] Read more.
Climate warming has already influenced the distribution, community composition, and phenology of European Odonata. Trithemis annulata had been confined to the southern regions of Italy for over 150 years. In only four decades, it has expanded its range and has recently been observed inhabiting several alpine valleys. A dataset of 2557 geographical distribution data points spanning the years 1825–2023 was compiled using various resources, with the aim to analyse the chrono-story of the expansion of T. annulata. A further aim was to investigate the climatic conditions that best explain its current and future distribution. Over a period of 43 years, the species steadily extended its northern range margin at an approximate rate of 12 km/year. Once it reached the Po Plain, the expansion accelerated to an average speed of 34 km/year. However, its northward shift lagged behind the warming climate as we estimated an average speed of 28 km/year. In the future, the area suitable for T. annulata is expected to significantly increase in Italy. Surprisingly, we did not observe any consistent upward shift. Trithemis annulata has considerably expanded its distribution due to human-induced climate warming. The northernmost populations now inhabit Alpine valleys, potential gateways to central Europe. Full article
(This article belongs to the Collection Ecology and Biology of Aquatic Insects)
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25 pages, 4241 KiB  
Systematic Review
Nanotechnology in Lubricants: A Systematic Review of the Use of Nanoparticles to Reduce the Friction Coefficient
by Milton Garcia Tobar, Rafael Wilmer Contreras Urgiles, Bryan Jimenez Cordero and Julio Guillen Matute
Lubricants 2024, 12(5), 166; https://doi.org/10.3390/lubricants12050166 - 9 May 2024
Abstract
The study of lubricating oil is paramount for the optimal functioning of modern engines, and it has generated intensive research in the automotive industry. The aim is to improve the tribological properties of lubricants by including nanomaterials as additives in base oils. This [...] Read more.
The study of lubricating oil is paramount for the optimal functioning of modern engines, and it has generated intensive research in the automotive industry. The aim is to improve the tribological properties of lubricants by including nanomaterials as additives in base oils. This article presents an exhaustive bibliographic review of the experiments carried out to optimize the tribological properties of nano-lubricants in order to identify the nanoparticles and experimental processes used and analyze the results obtained. The methodology adopted combines inductive and deductive elements. It begins with the formulation of a general theory on the application of nanoparticles in lubricants, followed by the collection of specific data on the conceptualization and preparation of nano-lubricants. A total of 176 articles focused on the application of nanoparticles in lubricants, especially to reduce the coefficient of friction, are reviewed. These works, with impact levels Q1 and Q2, delve into the application and are analyzed to review the obtained results. Most researchers worked with a nanoparticle concentration range of 0% to 1% by volume. Full article
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23 pages, 12372 KiB  
Article
Blast-Resistant Performance of Steel Petrochemical Control Room with 3D-Kagome Sandwich Wall
by Zhijun Li, Xinlong Dong, Dou Chen, Yan Jiang and Xuehua Li
Sustainability 2024, 16(10), 3967; https://doi.org/10.3390/su16103967 (registering DOI) - 9 May 2024
Abstract
As the control brain of the petrochemical plant, blast-resistant performance requirements are important for the sustainability of the petrochemical control room and should be guaranteed when the vapor cloud explosion occurs in the petrochemical production process. The 3D-Kagome truss core sandwich structure is [...] Read more.
As the control brain of the petrochemical plant, blast-resistant performance requirements are important for the sustainability of the petrochemical control room and should be guaranteed when the vapor cloud explosion occurs in the petrochemical production process. The 3D-Kagome truss core sandwich structure is a kind of blast-resistant material with high energy absorption and recycling. Considering the influential factors of the radius of the truss core rod and thickness of the upper and lower panels, in this paper, the blast-resistant performance of a real steel petrochemical control room with a 3D-Kagome truss core sandwich wall was analyzed. With the optimization goal of plastic deformation energy and panel displacement, the optimal wall thickness and radius of the truss core rod were obtained. The optimized blast-resistant walls were assembled, and the dynamic response of the steel petrochemical control room with the 3D-Kagome truss core sandwich blast-resistant wall was analyzed. The simulation results indicate that the truss core layer is ineffective in dissipating blast energy when the radius ratio of the truss core rod exceeds 2.7% of the total wall thickness. Moreover, as the thickness of the upper and lower panels increases from 0.5 cm to 3 cm, the proportion of plastic deformation energy in the truss core layer gradually rises from 55% to 95%, stabilizing at around 90%. The optimal configuration for blast resistance is achieved when the panel thickness ratio is 6.7% of the total wall thickness; the truss core rod radius ratio is 2.7% of the total thickness. This study establishes the effectiveness of the optimized 3D-Kagome sandwich wall as a blast-resistant solution for steel petrochemical control rooms. Full article
(This article belongs to the Section Green Building)
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14 pages, 5321 KiB  
Article
Synergistic Effect of Acrylate of Dialkyl Dithiophosphoric Acid Combined with Molybdenum Dialkyl Dithiocarbamate as Additives in Gear Oil
by Minghao Ding, Yimin Mo, Hong Zhang and Qingchun Liu
Lubricants 2024, 12(5), 165; https://doi.org/10.3390/lubricants12050165 - 9 May 2024
Abstract
With the aim of improving the tribological properties of low-viscosity gear oil for automobiles, an acrylate of dialkyl dithiophosphoric acid (ADDP) with strong polar groups was synthesized. The tribological behavior of ADDP combined with molybdenum dialkyl dithiocarbamate (MoDTC) in gear oil was systematically [...] Read more.
With the aim of improving the tribological properties of low-viscosity gear oil for automobiles, an acrylate of dialkyl dithiophosphoric acid (ADDP) with strong polar groups was synthesized. The tribological behavior of ADDP combined with molybdenum dialkyl dithiocarbamate (MoDTC) in gear oil was systematically studied. Tribological performances of gear oil containing different additives were assessed using a four-ball friction and wear tester. The obtained tribological characteristics reveal that ADDP and MoDTC can significantly improve the antiwear and antifriction performance of low-viscosity gear oil. Moreover, compared with using MoDTC or ADDP alone, the average friction coefficient and wear scar diameter of ADDP combined with MoDTC further decreased by 2.41–19.15% and 5.00–18.19%, respectively. Analysis of the worn surface showed that the structural characteristics and physical synergistic lubricating actions of the ADDP with MoDTC additives during the friction process can contribute to the exceptional tribological properties of the hybrid additives. Full article
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21 pages, 6387 KiB  
Article
Genistein–Aspirin Combination Exerts Cytotoxic and Anti-Migratory Effects in Human Colorectal Cancer Cells
by Claudia Iftode, Stela Iurciuc, Iasmina Marcovici, Ioana Macasoi, Dorina Coricovac, Cristina Dehelean, Sorin Ursoniu, Andreea Rusu and Simona Ardelean
Life 2024, 14(5), 606; https://doi.org/10.3390/life14050606 - 9 May 2024
Abstract
Colorectal cancer (CRC) is a heterogenous pathology with high incidence and mortality rates globally, but it is also preventable so finding the most promising candidates (natural compounds or repurposed drugs) to be chemopreventive alternatives has become a topic of interest in recent years. [...] Read more.
Colorectal cancer (CRC) is a heterogenous pathology with high incidence and mortality rates globally, but it is also preventable so finding the most promising candidates (natural compounds or repurposed drugs) to be chemopreventive alternatives has become a topic of interest in recent years. The present work aims to elucidate the potential effects of a combination between genistein (GEN), an isoflavone of natural origin, and aspirin (ASA) in CRC prevention/treatment by performing an in vitro evaluation in human colorectal cancer cells (HCT-116) and an in ovo analysis using the chick embryo chorioallantoic membrane (CAM) model. Cell viability was verified by an MTT (migratory potential by scratch) assay, and the expressions of MMP-2 and MMP-9 were analyzed using RT-qPCR. Our results indicated a dose-dependent cytotoxic effect of ASA (2.5 mM) + GEN (10–75 µM) combination characterized by reduced cell viability and morphological changes (actin skeleton reorganization and nuclei deterioration), an inhibition of HCT-116 cells’ migratory potential by down-regulating MMP-2 and MMP-9 mRNA expressions, and an antiangiogenic effect by modifying the vascular network. These promising results raise the possibility of future in-depth investigations regarding the chemopreventive/therapeutical potential of ASA+GEN combination. Full article
(This article belongs to the Special Issue Natural Bioactives: Exploring Their Therapeutic Potential)
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14 pages, 701 KiB  
Article
Non-Hermitian Quantum Rényi Entropy Dynamics in Anyonic-PT Symmetric Systems
by Zhihang Liu and Chao Zheng
Symmetry 2024, 16(5), 584; https://doi.org/10.3390/sym16050584 - 9 May 2024
Abstract
We reveal the continuous change of information dynamics patterns in anyonic-PT symmetric systems that originates from the continuity of anyonic-PT symmetry. We find there are three information dynamics patterns for anyonic-PT symmetric systems: damped oscillations with an overall decrease (increase) and asymptotically stable [...] Read more.
We reveal the continuous change of information dynamics patterns in anyonic-PT symmetric systems that originates from the continuity of anyonic-PT symmetry. We find there are three information dynamics patterns for anyonic-PT symmetric systems: damped oscillations with an overall decrease (increase) and asymptotically stable damped oscillations, which are three-fold degenerate and are distorted using the Hermitian quantum Rényi entropy or distinguishability. It is the normalization of the non-unitary evolved density matrix that causes the degeneracy and distortion. We give a justification for non-Hermitian quantum Rényi entropy being negative. By exploring the mathematics and physical meaning of the negative entropy in open quantum systems, we connect negative non-Hermitian quantum Rényi entropy and negative quantum conditional entropy, paving the way to rigorously investigate negative entropy in open quantum systems. Full article
(This article belongs to the Topic Quantum Information and Quantum Computing, 2nd Volume)
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21 pages, 2025 KiB  
Article
Global Models of Collapsing Scalar Field: Endstate
by Dario Corona and Roberto Giambò
Symmetry 2024, 16(5), 583; https://doi.org/10.3390/sym16050583 - 9 May 2024
Abstract
The study of dynamic singularity formation in spacetime, focusing on scalar field collapse models, is analyzed. We revisit key findings regarding open spatial topologies, concentrating on minimal conditions necessary for singularity and apparent horizon formation. Moreover, we examine the stability of initial data [...] Read more.
The study of dynamic singularity formation in spacetime, focusing on scalar field collapse models, is analyzed. We revisit key findings regarding open spatial topologies, concentrating on minimal conditions necessary for singularity and apparent horizon formation. Moreover, we examine the stability of initial data in the dynamical system governed by Einstein’s equations, considering variations in parameters that influence naked singularity formation. We illustrate how these results apply to a family of scalar field models, concluding with a discussion on the concept of genericity in singularity studies. Full article
(This article belongs to the Special Issue Recent Advance in Mathematical Physics II)
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16 pages, 3640 KiB  
Article
Use of Phosphite Preparations to Protect Ash Seedlings Fraxinus excelsior L. against Phytophthora spp. and Hymenoscyphus fraxineus Pathogens
by Artur Pacia, Stanisław Drozdowski, Tadeusz Malewski, Piotr Borowik, Konrad Wilamowski, Sławomir Bakier and Tomasz Oszako
Forests 2024, 15(5), 829; https://doi.org/10.3390/f15050829 - 9 May 2024
Abstract
In this study, greenhouse tests were conducted on 240 Fraxinus excelsior seedlings to investigate the simultaneous damage caused by thea pathogenic fungus and oomycetes. The experiment was performed under controlled conditions in the greenhouse of the Institute of Forest Research in Sękocin Stary [...] Read more.
In this study, greenhouse tests were conducted on 240 Fraxinus excelsior seedlings to investigate the simultaneous damage caused by thea pathogenic fungus and oomycetes. The experiment was performed under controlled conditions in the greenhouse of the Institute of Forest Research in Sękocin Stary (Poland). Three species of oomycetes were used for the experiment: Phytophthora plurivora, Phytophthora taxon hungarica, Phytophthora megasperma, and the fungus Hymenoscyphus fraxineus. Inoculations using the fungus were carried out on shoots and in plant pots in which the soil was mixed with the three Phytophthora species mentioned above, both simultaneously and separately, which made it possible to recognize the cumulative effect of the related plant infection. The aim of the study was to investigate the effect of phosphite-containing preparations on the health of common ash under conditions of threat to the roots by Phytophthora spp. and damage to the aerial parts of the plant by the fungus, as well as the possible occurrence of synergistic effects. Two types of protective preparations (Actifos and Phos60 of the nitrogen and potassium forms, respectively) were used. It was found that the inoculation of ash seedlings with the fungus H. fraxineus resulted in plant mortality, while the mixture of Phytophthora did not cause significant damage. It was confirmed that when pathogens coexist, a phenomenon occurs that leads to an acceleration in the development of disease symptoms and, thus, to plant mortality. In vitro tests confirmed the usefulness of phosphite preparations for the protection of ash seedlings. Full article
(This article belongs to the Section Forest Health)
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24 pages, 4118 KiB  
Article
Livelihood Alternatives in Restored Peatland Areas in South Sumatra Province, Indonesia
by Dessy Adriani, Muhammad Yazid, Riswani, Dini Damayanthy, Eunho Choi and Hyunyoung Yang
Land 2024, 13(5), 643; https://doi.org/10.3390/land13050643 - 9 May 2024
Abstract
Livelihood loss and lower income because of peatland mismanagement are crucial issues that must be resolved in peatland areas. Although many studies have assessed farmers’ livelihoods and income enhancement, progress in addressing these problems remains inadequate. To address this issue, this study aimed [...] Read more.
Livelihood loss and lower income because of peatland mismanagement are crucial issues that must be resolved in peatland areas. Although many studies have assessed farmers’ livelihoods and income enhancement, progress in addressing these problems remains inadequate. To address this issue, this study aimed to analyze various existing alternative livelihoods in the peatland community in Ogan Komering Ilir District, South Sumatra Province, Indonesia, and analyze scenarios for creating livelihoods and increasing people’s incomes through changes in peat ecosystem management and peatland restoration programs. This study used a survey method conducted in South Sumatra Province’s OKI District, one of the four priority peat-restoration districts in the province. We used three sampling stages, while descriptive, tabulated, and mathematical methods were used for analysis. We analyzed the feasibility of livelihoods that used benefit-cost analysis. The results showed that Sonor cultivation of paddies and catching fish in Rawang (swamp) were the livelihoods of farmers in peatlands. The community has also been processing peatland commodities into other products, such as Purun woven, and Gula Puan (buffalo milk processing). Several alternative livelihood scenarios that are financially profitable and can be developed include salted and smoked fish, Purun woven handicrafts, paludiculture, and agrosilvofishery, which can provide farmers with short-, medium-, and long-term income opportunities. This study can contribute to policymaking by fully considering the role of peat resources in rural livelihoods. Full article
(This article belongs to the Special Issue Restoration of Tropical Peatlands: Science Policy and Practice)
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14 pages, 2972 KiB  
Article
Treatment of Dairy Farm Runoff in Vegetated Bioretention Systems Amended with Biochar
by Md Yeasir A. Rahman, Nicholas Richardson, Mahmood H. Nachabe and Sarina J. Ergas
Water 2024, 16(10), 1347; https://doi.org/10.3390/w16101347 - 9 May 2024
Abstract
Nitrogen and fecal indicator bacteria (FIB) in runoff from concentrated animal feeding operations (CAFOs) can impair surface and groundwater quality. Bioretention systems are low impact nature-based technologies that can effectively treat CAFO runoff if modified with an internal water storage zone (IWSZ) or [...] Read more.
Nitrogen and fecal indicator bacteria (FIB) in runoff from concentrated animal feeding operations (CAFOs) can impair surface and groundwater quality. Bioretention systems are low impact nature-based technologies that can effectively treat CAFO runoff if modified with an internal water storage zone (IWSZ) or amended with biochar. In this study, the performances of four pilot-scale modified bioretention systems were compared to assess the impacts of (1) amending bioretention media with biochar and (2) planting the systems with Muhlenbergia. The system with both plants and biochar amendment had the best performance, with an average of 5.58 log reduction in E. coli and 98% removal of total nitrogen (TN). All systems treated the first pore volume well as new runoff flushed the treated water from the IWSZ. Biochar improved TN and FIB removal due to its high capacity to adsorb or retain ammonium (NH4+), dissolved organic nitrogen, dissolved organic carbon, and E. coli. Planting improved performance, possibly by increasing rhizosphere microbial activity. Full article
(This article belongs to the Section Wastewater Treatment and Reuse)
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16 pages, 4248 KiB  
Article
Molecular Composition of Humic Acids of Different Aged Fallow Lands and Soils of Different Types of Use in Northwest of Russia
by Vyacheslav Polyakov, Timur Nizamutdinov and Evgeny Abakumov
Agronomy 2024, 14(5), 996; https://doi.org/10.3390/agronomy14050996 - 9 May 2024
Abstract
Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids [...] Read more.
Post-agrogenic transformation of fallow soils leads to changes in soil carbon content, the molecular composition of humic substances, and rates of organic matter stabilization, which can affect climate change on the planet. In this regard, we analyzed the molecular composition of humic acids isolated from natural and fallow soils in the southern Taiga zone of northwest Russia. Different-aged soils on fallow lands represent a model of soil transformation in time, and data on the transformation of soil humic acid molecular composition make a significant contribution to the understanding of soil organic matter stabilization aspect issues. In this case, the molecular structure of humic acids isolated from natural and fallow soils in northwest Russia was analyzed. To study the molecular composition of HAs, the elemental composition was analyzed, and 13C (CP/MAS) NMR spectroscopy of HAs isolated from different aged abandoned soils and soils of different types of use was carried out. The obtained data showed that with the increasing age of soils in the fallow state, there is an increase in the carbon content of humic acids as well as a decrease in nitrogen content. As a result of the increasing age of soils in the fallow state, there are dynamics in the content of aromatic structural fragments in humic acids: 34% for 40 years old, 28% for 80 years old, and 31% for 120 years old. This is due to changes in the precursors of humification and the further transformation of plant residues in the soil. Re-involved fallow land soils lead to an increase in the content of aromatic structural fragments in the composition of HA in relation to HA extracted from mature soils. The lowest content of aromatic structural fragments was observed in the humic acids of 130-year-old agricultural soil, which is associated with the long-term application of organic fertilizers. Full article
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14 pages, 5024 KiB  
Article
Preparation of Polyoxymethylene/Exfoliated Molybdenum Disulfide Nanocomposite through Solid-State Shear Milling
by Shuo Feng, Xinwen Zhou, Sen Yang, Jiayu Tan, Meiqiong Chen, Yinghong Chen, Huarong Zhang, Xu Zhu, Shulong Wu and Haidong Gu
Polymers 2024, 16(10), 1334; https://doi.org/10.3390/polym16101334 - 9 May 2024
Abstract
In this paper, the solid-state shear milling (S3M) strategy featuring a very strong three-dimensional shear stress field was adopted to prepare the high-performance polyoxymethylene (POM)/molybdenum disulfide (MoS2) functional nanocomposite. The transmission electron microscope and Raman measurement results confirmed that [...] Read more.
In this paper, the solid-state shear milling (S3M) strategy featuring a very strong three-dimensional shear stress field was adopted to prepare the high-performance polyoxymethylene (POM)/molybdenum disulfide (MoS2) functional nanocomposite. The transmission electron microscope and Raman measurement results confirmed that the bulk MoS2 particle was successfully exfoliated into few-layer MoS2 nanoplatelets by the above simple S3M physical method. The polarized optical microscope (PLM) observation indicated the pan-milled nanoscale MoS2 particles presented a better dispersion performance in the POM matrix. The results of the tribological test indicated that the incorporation of MoS2 could substantially improve the wear resistance performance of POM. Moreover, the pan-milled exfoliated MoS2 nanosheets could further substantially decrease the friction coefficient of POM. Scanning electron microscope observations on the worn scar revealed the tribological mechanism of the POM/MoS2 nanocomposite prepared by solid-state shear milling. The tensile test results showed that the pan-milled POM/MoS2 nanocomposite has much higher elongation at break than the conventionally melt-compounded material. The solid-state shear milling strategy shows a promising prospect in the preparation of functional nanocomposite with excellent comprehensive performance at a large scale. Full article
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19 pages, 6417 KiB  
Article
Alternating Current Electrospinning of Polycaprolactone/Chitosan Nanofibers for Wound Healing Applications
by Jon Andrade del Olmo, Petr Mikeš, Nikifor Asatiani, José María Alonso, Virginia Sáez Martínez and Raúl Pérez González
Polymers 2024, 16(10), 1333; https://doi.org/10.3390/polym16101333 - 9 May 2024
Abstract
Traditional wound dressings have not been able to satisfy the needs of the regenerative medicine biomedical area. With the aim of improving tissue regeneration, nanofiber-based wound dressings fabricated by electrospinning (ES) processes have emerged as a powerful approach. Nowadays, nanofiber-based bioactive dressings are [...] Read more.
Traditional wound dressings have not been able to satisfy the needs of the regenerative medicine biomedical area. With the aim of improving tissue regeneration, nanofiber-based wound dressings fabricated by electrospinning (ES) processes have emerged as a powerful approach. Nowadays, nanofiber-based bioactive dressings are mainly developed with a combination of natural and synthetic polymers, such as polycaprolactone (PCL) and chitosan (CHI). Accordingly, herein, PCL/CHI nanofibers have been developed with varying PCL:CHI weight ratios (9:1, 8:2 and 7:3) or CHI viscosities (20, 100 and 600 mPa·s) using a novel alternating current ES (ACES) process. Such nanofibers were thoroughly characterized by determining physicochemical and nanomechanical properties, along with wettability, absorption capacity and hydrolytic plus enzymatic stability. Furthermore, PCL/CHI nanofiber biological safety was validated in terms of cytocompatibility and hemocompatibility (hemolysis < 2%), in addition to a notable antibacterial performance (bacterial reductions of 99.90% for S. aureus and 99.91% for P. aeruginosa). Lastly, the enhanced wound healing activity of PCL/CHI nanofibers was confirmed thanks to their ability to remarkably promote cell proliferation, which make them ideal candidates for long-term applications such as wound dressings. Full article
(This article belongs to the Special Issue Biocompatible and Biodegradable Polymers for Medical Applications II)
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11 pages, 257 KiB  
Article
Diffusing Wave Microrheology in Polymeric Fluids
by George David Joseph Phillies
Polymers 2024, 16(10), 1332; https://doi.org/10.3390/polym16101332 - 9 May 2024
Abstract
Recently, there has been interest in determining the viscoelastic properties of polymeric liquids and other complex fluids by means of Diffusing Wave Spectroscopy (DWS). In this technique, light-scattering spectroscopy is applied to highly turbid fluids containing optical probe particles. The DWS spectrum is [...] Read more.
Recently, there has been interest in determining the viscoelastic properties of polymeric liquids and other complex fluids by means of Diffusing Wave Spectroscopy (DWS). In this technique, light-scattering spectroscopy is applied to highly turbid fluids containing optical probe particles. The DWS spectrum is used to infer the time-dependent mean-square displacement and time-dependent diffusion coefficient D of the probes. From D, values for the storage modulus G(ω) and the loss modulus G(ω) are obtained. This paper is primarily concerned with the inference of the mean-square displacement from a DWS spectrum. However, in much of the literature, central to the inference that is said to yield D is an invocation g(1)(t)=exp(2q2X(t)2¯) of the Gaussian Approximation for the field correlation function g(1)(t) of the scattered light in terms of the mean-square displacement X(t)2¯ of a probe particle during time t. Experiment and simulation both show that the Gaussian approximation is invalid for probes in polymeric liquids and other complex fluids. In this paper, we obtain corrections to the Gaussian approximation that will assist in interpreting DWS spectra of probes in polymeric liquids. The corrections reveal that these DWS spectra receive contributions from higher moments X(t)2n¯, n>1, of the probe displacement distribution function. Full article
(This article belongs to the Section Polymer Physics and Theory)
14 pages, 7940 KiB  
Article
Tension and Shear Behaviour of Basalt Fiber Bio-Composites with Digital Image Correlation and Acoustic Emission Monitoring
by Tomaž Kek, Roman Šturm and Zoran Bergant
Polymers 2024, 16(10), 1331; https://doi.org/10.3390/polym16101331 - 9 May 2024
Abstract
This research investigates the mechanical behavior and damage evolution in cross-ply basalt fiber composites subjected to different loading modes. A modified Arcan rig for simultaneous acoustic emission (AE) monitoring was designed and manufactured to apply quasi-isotropic shear, combined tensile and shear loading, and [...] Read more.
This research investigates the mechanical behavior and damage evolution in cross-ply basalt fiber composites subjected to different loading modes. A modified Arcan rig for simultaneous acoustic emission (AE) monitoring was designed and manufactured to apply quasi-isotropic shear, combined tensile and shear loading, and pure tensile loading on specimens with a central notch. Digital image correlation (DIC) was applied for high-resolution strain measurements. The measured failure strengths of the bio-composite specimens under different loading angles are presented. The different competing failure mechanisms that contribute to the local reduction in stress concentration are described. Different damage mechanisms trigger elastic waves in the composite, with distinct AE signatures that closely follow the sequence of fracture mechanisms. AE monitoring is employed to capture signals associated with structural damage initiation and progression. The characteristic parameters of AE signals are correlated with crack modes and damage mechanisms. The evolution of AE parameters during the peak load transition is presented, which enables the timely AE detection of the maximum load transition. The combination of DIC and AE monitoring improves understanding of the mechanical response and failure mechanisms in cross-ply basalt fiber composites, offering valuable insights for possible performance monitoring and structural reliability in diverse engineering applications. Full article
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15 pages, 2189 KiB  
Article
Bulk Free Radical Terpolymerization of Butyl Acrylate, 2-Methylene-1,3-Dioxepane and Vinyl Acetate: Terpolymer Reactivity Ratio Estimation
by Maryam Movafagh, Kelly M. Meek, Alison J. Scott, Alexander Penlidis and Marc A. Dubé
Polymers 2024, 16(10), 1330; https://doi.org/10.3390/polym16101330 - 9 May 2024
Abstract
This investigation introduces the first estimation of ternary reactivity ratios for a butyl acrylate (BA), 2-methylene-1,3-dioxepane (MDO), and vinyl acetate (VAc) system at 50 °C, with an aim to develop biodegradable pressure-sensitive adhesives (PSAs). In this study, we applied the error-in-variables model (EVM) [...] Read more.
This investigation introduces the first estimation of ternary reactivity ratios for a butyl acrylate (BA), 2-methylene-1,3-dioxepane (MDO), and vinyl acetate (VAc) system at 50 °C, with an aim to develop biodegradable pressure-sensitive adhesives (PSAs). In this study, we applied the error-in-variables model (EVM) to estimate reactivity ratios. The ternary reactivity ratios were found to be r12 = 0.417, r21 = 0.071, r13 = 4.459, r31 = 0.198, r23 = 0.260, and r32 = 55.339 (BA/MDO/VAc 1/2/3), contrasting with their binary counterparts, which are significantly different, indicating the critical need for ternary system analysis to accurately model multicomponent polymerization systems. Through the application of a recast Alfrey–Goldfinger model, this investigation predicts the terpolymer’s instantaneous and cumulative compositions at various conversion levels, based on the ternary reactivity ratios. These predictions not only provide crucial insights into the incorporation of MDO across different initial feed compositions but also offer estimates of the final terpolymer compositions and distributions, underscoring their potential in designing compostable or degradable polymers. Full article
(This article belongs to the Special Issue State-of-the-Art Polymer Science and Technology in Canada)
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29 pages, 1895 KiB  
Article
An Efficient Attribute-Based Participant Selecting Scheme with Blockchain for Federated Learning in Smart Cities
by Xiaojun Yin, Haochen Qiu, Xijun Wu and Xinming Zhang
Computers 2024, 13(5), 118; https://doi.org/10.3390/computers13050118 - 9 May 2024
Abstract
In smart cities, large amounts of multi-source data are generated all the time. A model established via machine learning can mine information from these data and enable many valuable applications. With concerns about data privacy, it is becoming increasingly difficult for the publishers [...] Read more.
In smart cities, large amounts of multi-source data are generated all the time. A model established via machine learning can mine information from these data and enable many valuable applications. With concerns about data privacy, it is becoming increasingly difficult for the publishers of these applications to obtain users’ data, which hinders the previous paradigm of centralized training through collecting data on a large scale. Federated learning is expected to prevent the leakage of private data by allowing users to train models locally. The existing works generally ignore architectures designed in real scenarios. Thus, there still exist some challenges that have not yet been explored in federated learning applied in smart cities, such as avoiding sharing models with improper parties under privacy requirements and designing satisfactory incentive mechanisms. Therefore, we propose an efficient attribute-based participant selecting scheme to ensure that only someone who meets the requirements of the task publisher can participate in training under the premise of high privacy requirements, so as to improve the efficiency and avoid attacks. We further extend our scheme to encourage clients to take part in federated learning and provide an audit mechanism using a consortium blockchain. Finally, we present an in-depth discussion of the proposed scheme by comparing it to different methods. The results show that our scheme can improve the efficiency of federated learning by enabling reliable participant selection and promote the extensive use of federated learning in smart cities. Full article
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25 pages, 1646 KiB  
Review
Catalyzing Precision Medicine: Artificial Intelligence Advancements in Prostate Cancer Diagnosis and Management
by Ali Talyshinskii, B. M. Zeeshan Hameed, Prajwal P. Ravinder, Nithesh Naik, Princy Randhawa, Milap Shah, Bhavan Prasad Rai, Theodoros Tokas and Bhaskar K. Somani
Cancers 2024, 16(10), 1809; https://doi.org/10.3390/cancers16101809 - 9 May 2024
Abstract
Background: The aim was to analyze the current state of deep learning (DL)-based prostate cancer (PCa) diagnosis with a focus on magnetic resonance (MR) prostate reconstruction; PCa detection/stratification/reconstruction; positron emission tomography/computed tomography (PET/CT); androgen deprivation therapy (ADT); prostate biopsy; associated challenges and their [...] Read more.
Background: The aim was to analyze the current state of deep learning (DL)-based prostate cancer (PCa) diagnosis with a focus on magnetic resonance (MR) prostate reconstruction; PCa detection/stratification/reconstruction; positron emission tomography/computed tomography (PET/CT); androgen deprivation therapy (ADT); prostate biopsy; associated challenges and their clinical implications. Methods: A search of the PubMed database was conducted based on the inclusion and exclusion criteria for the use of DL methods within the abovementioned areas. Results: A total of 784 articles were found, of which, 64 were included. Reconstruction of the prostate, the detection and stratification of prostate cancer, the reconstruction of prostate cancer, and diagnosis on PET/CT, ADT, and biopsy were analyzed in 21, 22, 6, 7, 2, and 6 studies, respectively. Among studies describing DL use for MR-based purposes, datasets with magnetic field power of 3 T, 1.5 T, and 3/1.5 T were used in 18/19/5, 0/1/0, and 3/2/1 studies, respectively, of 6/7 studies analyzing DL for PET/CT diagnosis which used data from a single institution. Among the radiotracers, [68Ga]Ga-PSMA-11, [18F]DCFPyl, and [18F]PSMA-1007 were used in 5, 1, and 1 study, respectively. Only two studies that analyzed DL in the context of DT met the inclusion criteria. Both were performed with a single-institution dataset with only manual labeling of training data. Three studies, each analyzing DL for prostate biopsy, were performed with single- and multi-institutional datasets. TeUS, TRUS, and MRI were used as input modalities in two, three, and one study, respectively. Conclusion: DL models in prostate cancer diagnosis show promise but are not yet ready for clinical use due to variability in methods, labels, and evaluation criteria. Conducting additional research while acknowledging all the limitations outlined is crucial for reinforcing the utility and effectiveness of DL-based models in clinical settings. Full article
(This article belongs to the Section Cancer Causes, Screening and Diagnosis)
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9 pages, 2226 KiB  
Article
Resonance Modes of Water Drops Pinned to a Vibrating Rectangular Post
by Paolo Sartori, Davide Ferraro, Matteo Pierno and Giampaolo Mistura
Micromachines 2024, 15(5), 634; https://doi.org/10.3390/mi15050634 - 9 May 2024
Abstract
We studied the effects of vertical vibrations on a water drop that was pinned to the sharp edges of a rectangular post. By varying the frequency and amplitude of the vertical displacement, distinct resonance peaks were observed using a simple optical technique. The [...] Read more.
We studied the effects of vertical vibrations on a water drop that was pinned to the sharp edges of a rectangular post. By varying the frequency and amplitude of the vertical displacement, distinct resonance peaks were observed using a simple optical technique. The vibrational spectra of the first two modes exhibited two closely spaced peaks, which corresponded to standing waves that exist along the major and minor contour lengths of the drops. The values of the resonance frequencies can be explained rather well by a simple model, which was originally proposed for axially symmetric drops. Full article
(This article belongs to the Section A:Physics)
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15 pages, 4414 KiB  
Article
Ti3AlC2 MAX Phase Modified Screen-Printed Electrode for the Fabrication of Hydrazine Sensor
by Khursheed Ahmad, Waseem Raza and Rais Ahmad Khan
Micromachines 2024, 15(5), 633; https://doi.org/10.3390/mi15050633 - 9 May 2024
Abstract
Hydrazine is considered a powerful reducing agent and catalyst, showing diverse applications in agricultural industries, toxic degradation research, and wastewater management. Additionally, hydrazine can trigger some specific reactions when combined with suitable oxidants. Due to its highly polar nature, hydrazine can easily dissolve [...] Read more.
Hydrazine is considered a powerful reducing agent and catalyst, showing diverse applications in agricultural industries, toxic degradation research, and wastewater management. Additionally, hydrazine can trigger some specific reactions when combined with suitable oxidants. Due to its highly polar nature, hydrazine can easily dissolve in alcohol, water, and various other polar solvents. Therefore, it can be extensively utilized in different areas of application and industries such as rocketry and various chemical applications. Despite its beneficial properties, hydrazine is unstable, posing significant risk due to its highly toxic nature. It is extremely hazardous to both human health and the environment. It can cause various illnesses and symptoms such as dizziness, temporary blindness, damage to the central nervous system, and even death when inhaled in sufficient quantities. Therefore, it is highly important to monitor the level of hydrazine to prevent its toxic and hazardous effects on human beings and the environment. In the present study, we discuss the simple fabrication of a disposable cost-effective and eco-friendly hydrazine sensor. We used a screen-printed carbon electrode, i.e., SPCE, as a base for the construction of a hydrazine sensor. The Ti3AlC2 MAX has been used as a suitable and efficient electrode material for the fabrication of disposable hydrazine sensors. We modified the active surface of the SPCE using a drop-casting approach. The resulting Ti3AlC2 MAX modified SPCE (Ti3AlC2@SPCE) has been utilized as an efficient and low-cost hydrazine sensor. Cyclic voltammetry, i.e., CV, and linear sweep voltammetry, viz., LSV, was employed as a sensing technique in this study. The optimization of pH and electrode material loading was conducted. The Ti3AlC2@SPCE exhibited excellent sensing performance toward hydrazine oxidation. A reasonable detection limit (0.01 µM) was achieved for hydrazine sensing. The fabricated sensor also demonstrated a reasonable linear range of 1–50 µM. This work provides the design and fabrication of simple disposable Ti3AlC2@SPCE as a suitable electrode for the determination of hydrazine using LSV technology. Full article
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