The 2023 MDPI Annual Report has
been released!
 
21 pages, 305 KiB  
Article
Characterization of Pseudo-Differential Operators Associated with the Coupled Fractional Fourier Transform
by Shraban Das, Kanailal Mahato and Ahmed I. Zayed
Axioms 2024, 13(5), 296; https://doi.org/10.3390/axioms13050296 (registering DOI) - 28 Apr 2024
Abstract
The main aim of this article is to derive certain continuity and boundedness properties of the coupled fractional Fourier transform on Schwartz-like spaces. We extend the domain of the coupled fractional Fourier transform to the space of tempered distributions and then study the [...] Read more.
The main aim of this article is to derive certain continuity and boundedness properties of the coupled fractional Fourier transform on Schwartz-like spaces. We extend the domain of the coupled fractional Fourier transform to the space of tempered distributions and then study the mapping properties of pseudo-differential operators associated with the coupled fractional Fourier transform on a Schwartz-like space. We conclude the article by applying some of the results to obtain an analytical solution of a generalized heat equation. Full article
10 pages, 244 KiB  
Article
Higher Blood Lactate with Prolongation of Underwater Section in Submaximal Front-Crawl Swimming
by Tomas Venckunas and Justas Achramavicius
Sports 2024, 12(5), 121; https://doi.org/10.3390/sports12050121 (registering DOI) - 28 Apr 2024
Abstract
The underwater phase (UP) is highly important for overall swimming performance in most swimming events. However, the metabolic effects of the prolonged UP remain unclear. The purpose of this cross-sectional study was to compare the blood lactate response to submaximal front-crawl swimming with [...] Read more.
The underwater phase (UP) is highly important for overall swimming performance in most swimming events. However, the metabolic effects of the prolonged UP remain unclear. The purpose of this cross-sectional study was to compare the blood lactate response to submaximal front-crawl swimming with short and extended UP. Twelve (four females) junior competitive swimmers (aged 15.4 (1.4) years) undertook 200 m front-crawl swim trials in a 25 m pool at a pre-determined “anaerobic threshold” velocity on two occasions using short (<5 m) and extended (12.5 m) UP after each turn. Pacing and total time were ensured to be identical between the trials. Capillary blood lactate response was measured. Testing for 25 m swim time with <5 m and 12.5 m UP was conducted on a separate occasion. When athletes undertook and extended UP after each propulsion from the wall, their post-exercise blood lactate concentration reached 7.9 (2.1) mmol/L, more than two times higher than the response to trial with short UP (p < 0.001). All-out 25 m swimming with <5 m or 12.5 m UP disclosed no difference in locomotion velocity (p > 0.05). In conclusion, extending UP of submaximal front-crawl swimming close to maximally allowed during the races substantially increases blood lactate accumulation, i.e., increases the reliance on anaerobic metabolism. Therefore, extended UP is most likely counterproductive for the performance in long-distance swimming, at least for the athletes with a FINA score of <800. On the other hand, the extension of UP could be an effective strategy to train ‘lactate tolerance’, lactate shuttling, removal, and recycling. Full article
15 pages, 2959 KiB  
Article
Optimizing Stainless Steel Bearings: Enhancement of Stainless Steel Bearing Fatigue Life by Low-Temperature Forming
by Alexander Heinrich Bodewig, Florian Pape and Gerhard Poll
Metals 2024, 14(5), 512; https://doi.org/10.3390/met14050512 (registering DOI) - 28 Apr 2024
Abstract
A proposed low-temperature forging method is presented to enhance stainless steel bearings by creating a martensitic subsurface layer, significantly boosting bearing fatigue life due to increased surface hardness. This technique induces beneficial residual stresses, particularly in axial bearings, streamlining their construction and improving [...] Read more.
A proposed low-temperature forging method is presented to enhance stainless steel bearings by creating a martensitic subsurface layer, significantly boosting bearing fatigue life due to increased surface hardness. This technique induces beneficial residual stresses, particularly in axial bearings, streamlining their construction and improving machine elements. Challenges persist, especially with radial bearings, but simplicity in axial bearing forging promotes compact, resource-efficient facility construction. Future research will focus on applying this technique to axial bearing washers, potentially replicating success in other bearing components. Despite the energy expenditure on cooling during forging, the substantial increase in bearing fatigue life offsets this, enhancing overall durability and reliability of critical machine components. Integration of this forging technique into bearing fabrication appears seamless, offering a promising trade-off between energy use and enhanced performance. Full article
20 pages, 489 KiB  
Article
Navigating Kazakhstan’s Sustainable Economic Future: A Study of Tech Innovation, Infrastructure, and Resource Management
by Gani Rakhymzhan, Nazym Esbergenovna Dabyltayeva, Gaukhar Sakhanova, Elvira Abdulmitovna Ruziyeva and Assemgul Bauirzhanovna Bekmukhametova
Economies 2024, 12(5), 104; https://doi.org/10.3390/economies12050104 (registering DOI) - 28 Apr 2024
Abstract
In a quest to illuminate Kazakhstan’s economic horizon within a sustainable context, this study delved into the complex interplay of sustainable tech innovation, investment in sustainable infrastructure, and natural resource management. The study assesses the potential for green economy development by introducing the [...] Read more.
In a quest to illuminate Kazakhstan’s economic horizon within a sustainable context, this study delved into the complex interplay of sustainable tech innovation, investment in sustainable infrastructure, and natural resource management. The study assesses the potential for green economy development by introducing the adoption of sustainable practices as the mediator and corporate social responsibility as the moderator in the examined relationships. We employed a cluster sampling technique, focusing on government sector employees in Kazakhstan. The choice of this sector stemmed from its pivotal role in shaping national policies. A time-lagged approach was incorporated, collecting data at two distinct time points to capture the dynamic evolution of green initiatives over time. As the data unfolded, sustainable tech innovation, investment in sustainable infrastructure, and natural resource management emerged as significant predictors for adopting environmentally responsible practices leading to green economy development. This development process, we found, was further augmented by the moderating influence of corporate social responsibility. Hence, our findings contribute both practical and theoretical insights to the discourse on sustainable economic development. In addressing the intricate interplay of technological, infrastructural, and resource-related factors, this study provides guidance for Kazakhstan’s ongoing transition towards a more sustainable and resilient economic trajectory. Full article
20 pages, 329 KiB  
Article
Challenges of Using Artificial Intelligence in the Process of Shi’i Ijtihad
by Hasan Latifi
Religions 2024, 15(5), 541; https://doi.org/10.3390/rel15050541 (registering DOI) - 28 Apr 2024
Abstract
This article aims to explore the potential challenges that may arise when employing generative AI models in the process of Shi’i ijtihad. By drawing upon academic literature and relevant primary sources, the essay surveys the most critical AI-related hurdles in this field, [...] Read more.
This article aims to explore the potential challenges that may arise when employing generative AI models in the process of Shi’i ijtihad. By drawing upon academic literature and relevant primary sources, the essay surveys the most critical AI-related hurdles in this field, including issues of accessibility, privacy concerns, the problem of “AI hallucination” and the generative nature of AI models, biases in AI systems, the lack of transparency and inexplicability, the intricacies of interpreting and understanding sensitive topics, accountability, authority, trust and acceptance among lay believers. Using discourse and content analysis as method, the article concludes that, given these challenges, generative AI models are not yet suitable for utilization in this process. However, the rapid progress in AI may eventually make it an effective tool for this purpose. Full article
(This article belongs to the Special Issue Theology and Science: Loving Science, Discovering the Divine)
13 pages, 286 KiB  
Systematic Review
Klotho as an Early Marker of Acute Kidney Injury Following Cardiac Surgery: A Systematic Review
by Konstantinos S. Mylonas, Panagiotis Karakitsos, Alireza Tajik, Deanna Pagliuso, Hamidreza Emadzadeh, Ioanna Soukouli, Pouya Hemmati, Dimitrios V. Avgerinos, George T. Stavridis and John N. Boletis
J. Cardiovasc. Dev. Dis. 2024, 11(5), 135; https://doi.org/10.3390/jcdd11050135 (registering DOI) - 28 Apr 2024
Abstract
Acute kidney injury is a common complication following cardiac surgery (CSA-AKI). Serum creatinine levels require a minimum of 24–48 h to indicate renal injury. Nevertheless, early diagnosis remains critical for improving patient outcomes. A PRISMA-compliant systematic review of the PubMed and CENTRAL databases [...] Read more.
Acute kidney injury is a common complication following cardiac surgery (CSA-AKI). Serum creatinine levels require a minimum of 24–48 h to indicate renal injury. Nevertheless, early diagnosis remains critical for improving patient outcomes. A PRISMA-compliant systematic review of the PubMed and CENTRAL databases was performed to assess the role of Klotho as a predictive biomarker for CSA-AKI (end-of-search date: 17 February 2024). An evidence quality assessment of the four included studies was performed with the Newcastle–Ottawa scale. Among the 234 patients studied, 119 (50.8%) developed CSA-AKI postoperatively. Serum Klotho levels above 120 U/L immediately postoperatively correlated with an area under the curve (AUC) of 0.806 and 90% sensitivity. Additionally, a postoperative serum creatinine to Klotho ratio above 0.695 showed 94.7% sensitivity and 87.5% specificity, with an AUC of 92.4%, maintaining its prognostic validity for up to three days. Urinary Klotho immunoreactivity was better maintained in samples obtained via direct catheterization rather than indwelling catheter collection bags. Storage at −80 °C was necessary for delayed testing. Optimal timing for both serum and urine Klotho measurements was from the end of cardiopulmonary bypass to the time of the first ICU lab tests. In conclusion, Klotho could be a promising biomarker for the early diagnosis of CSA-AKI. Standardization of measurement protocols and larger studies are needed to validate these findings. Full article
(This article belongs to the Section Cardiac Surgery)
19 pages, 3578 KiB  
Article
Exploring the Therapeutic Potential of Spilanthol from Acmella paniculata (Wall ex DC.) R. K. Jansen in Attenuating Neurodegenerative Diseases: A Multi-Faceted Approach Integrating In Silico and In Vitro Methodologies
by Sanith Sri Jayashan, Nitchakan Darai, Thanyada Rungrotmongkol, Peththa Wadu Dasuni Wasana, San Yoon Nwe, Wisuwat Thongphichai, Gunasekaran Suriyakala, Pasarapa Towiwat and Suchada Sukrong
Appl. Sci. 2024, 14(9), 3755; https://doi.org/10.3390/app14093755 (registering DOI) - 28 Apr 2024
Abstract
Neurodegenerative diseases (NDDs) are marked by progressive degeneration of neurons within the central nervous system. A notable rise in the prevalence of NDDs has been noticed in the recent past. There is an undeniable requirement for the discovery of innovative therapies aimed at [...] Read more.
Neurodegenerative diseases (NDDs) are marked by progressive degeneration of neurons within the central nervous system. A notable rise in the prevalence of NDDs has been noticed in the recent past. There is an undeniable requirement for the discovery of innovative therapies aimed at treating NDDs, as current medications predominantly address symptoms rather than provide cures. Approved therapies often experience a decline in therapeutic efficacy over time and are associated with significant side effects. The current investigation explores the potential of spilanthol, the major bioactive compound isolated from Acmella paniculata, in attenuating NDDs through a multi-faceted approach combining in silico, and in vitro methodologies. In silico pharmacokinetic and toxicity screening of spilanthol indicated favorable characteristics for oral delivery, blood–brain barrier permeability, and minimal toxicity. Network pharmacology predicts that spilanthol attenuates neuroinflammation in NDDs by suppressing the toll-like receptor signaling pathway. Molecular docking and dynamics simulations demonstrate robust binding affinities between spilanthol and key proteins in the TLR4 pathway. In vitro experiments conducted using BV-2 microglial cells demonstrate the potential of spilanthol to reduce the production of proinflammatory cytokines and mediators such as NO, TNF-α, and IL-6 induced by lipopolysaccharide. The cumulative findings of the present study indicate that spilanthol mitigates neurodegeneration by alleviating neuroinflammation. Full article
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27 pages, 6749 KiB  
Article
Performance Prediction and Optimization of Nanofluid-Based PV/T Using Numerical Simulation and Response Surface Methodology
by Sreehari Sreekumar, Supriya Chakrabarti, Neil Hewitt, Jayanta Deb Mondol and Nikhilkumar Shah
Nanomaterials 2024, 14(9), 774; https://doi.org/10.3390/nano14090774 (registering DOI) - 28 Apr 2024
Abstract
A numerical investigation was carried out in ANSYS Fluent® on a photovoltaic/thermal (PV/T) system with MXene/water nanofluid as heat transfer fluid (HTF). The interaction of different operating parameters (nanofluid mass fraction, mass flow rate, inlet temperature and incident radiation) on the output [...] Read more.
A numerical investigation was carried out in ANSYS Fluent® on a photovoltaic/thermal (PV/T) system with MXene/water nanofluid as heat transfer fluid (HTF). The interaction of different operating parameters (nanofluid mass fraction, mass flow rate, inlet temperature and incident radiation) on the output response of the system (thermal efficiency, electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency) was studied using a predictive model generated using response surface methodology (RSM). The analysis of variance (ANOVA) method was used to evaluate the significance of input parameters affecting the energy and exergy efficiencies of the nanofluid-based PV/T system. The nanofluid mass flow rate was discovered to be having an impact on the thermal efficiency of the system. Electrical efficiency, thermal exergy efficiency, and electrical exergy efficiency were found to be greatly influenced by incident solar radiation. The percentage contribution of each factor on the output response was calculated. Input variables were optimized using the desirability function to maximize energy and exergy efficiency. The developed statistical model generated an optimum value for the mass flow rate (71.84 kgh−1), the mass fraction (0.2 wt%), incident radiation (581 Wm−2), and inlet temperature (20 °C). The highest overall energy and exergy efficiency predicted by the model were 81.67% and 18.6%, respectively. Full article
(This article belongs to the Special Issue Nano-Enabled Materials for Clean Water and Energy Generation)
20 pages, 2175 KiB  
Article
Performance Evaluation of Grounding Systems of Medium-Voltage Concrete Poles: A Comprehensive Analysis
by Emmanouil D. Ellinas, Georgios Lianos, Vassiliki T. Kontargyri, Christos A. Christodoulou and Ioannis F. Gonos
Appl. Sci. 2024, 14(9), 3758; https://doi.org/10.3390/app14093758 (registering DOI) - 28 Apr 2024
Abstract
Designing and installing efficient grounding systems in power distribution networks is considered a complex and crucial task to ensure the reliable operation of power-protective schemes while mitigating hazardous potentials arising from faults, thereby safeguarding both personnel and equipment. This paper aims to offer [...] Read more.
Designing and installing efficient grounding systems in power distribution networks is considered a complex and crucial task to ensure the reliable operation of power-protective schemes while mitigating hazardous potentials arising from faults, thereby safeguarding both personnel and equipment. This paper aims to offer guidance on designing effective grounding systems in distribution networks by assessing the influence of parameters such as soil structure, fault current magnitude, and fault clearing time. This involves proposing a more precise methodology for calculating hazardous potentials, leveraging software tools like PowerFactory, to accurately determine short-circuit (SC) currents and fault clearing times at specific locations where grounding grids are to be installed. Consequently, Distribution System Operators (DSOs) can design tailored grounding systems that optimize techno-economic considerations without unnecessary over-dimensioning, accounting for the unique characteristics of the Medium-Voltage (MV) Line and soil structure. Full article
(This article belongs to the Section Energy Science and Technology)
28 pages, 8120 KiB  
Article
Higher Time-Derivative Theories from Space–Time Interchanged Integrable Field Theories
by Andreas Fring, Takano Taira and Bethan Turner
Universe 2024, 10(5), 198; https://doi.org/10.3390/universe10050198 (registering DOI) - 28 Apr 2024
Abstract
We compare a relativistic and a nonrelativistic version of Ostrogradsky’s method for higher-time derivative theories extended to scalar field theories and consider as an alternative a multi-field variant. We apply the schemes to space–time rotated modified Korteweg–de Vries systems and, exploiting their integrability, [...] Read more.
We compare a relativistic and a nonrelativistic version of Ostrogradsky’s method for higher-time derivative theories extended to scalar field theories and consider as an alternative a multi-field variant. We apply the schemes to space–time rotated modified Korteweg–de Vries systems and, exploiting their integrability, to Hamiltonian systems built from space–time rotated inverse Legendre transformed higher-order charges of these systems. We derive the equal-time Poisson bracket structures of these theories, establish the integrability of the latter theories by means of the Painlevé test and construct exact analytical period benign solutions in terms of Jacobi elliptic functions to the classical equations of motion. The classical energies of these partially complex solutions are real when they respect a certain modified CPT-symmetry and complex when this symmetry is broken. The higher-order Cauchy and initial-boundary value problem are addressed analytically and numerically. Finally, we provide the explicit quantization of the simplest mKdV system, exhibiting the usual conundrum of having the choice between having to deal with either a theory that includes non-normalizable states or spectra that are unbounded from below. In our non-Hermitian system, the choice is dictated by the correct sign in the decay width. Full article
(This article belongs to the Section Field Theory)
10 pages, 251 KiB  
Article
Primary Health Care Case-Management Nurses during the COVID-19 Pandemic: A Qualitative Study
by María José Molina-Gil, María Dolores Guerra-Martín and Rocío De Diego-Cordero
Nurs. Rep. 2024, 14(2), 1119-1128; https://doi.org/10.3390/nursrep14020084 (registering DOI) - 28 Apr 2024
Abstract
The COVID-19 has caused high morbidity and mortality in vulnerable people, such as those affected by chronic diseases, and case-management nurses (CMNs) are reference professionals for their health care and management. The objective of this study is to better understand the discourse, experiences, [...] Read more.
The COVID-19 has caused high morbidity and mortality in vulnerable people, such as those affected by chronic diseases, and case-management nurses (CMNs) are reference professionals for their health care and management. The objective of this study is to better understand the discourse, experiences, and feelings about the professional performance of CMNs during the pandemic. A qualitative study was conducted by conducting semi-structured interviews with CMNs (n = 31) from the province of Seville (Spain) and performing a narrative discourse analysis. The Atlas Ti 6.2 software program was used. Two categories were defined: 1. CMNs’ competencies (76 verbatim testimonies); and 2. Consequences of the COVID-19 pandemic (61 verbatim testimonies). This study was granted due permission by the Research Ethics Committee belonging to the University of Seville, under protocol code: 1139-N-22. The pandemic caused an increase in CMNs’ workload, and they had to assume their usual care tasks for vulnerable populations in addition to simultaneously prioritizing assistance in nursing homes. We can highlight CMNs’ adaptation to the pandemic situation and to these new requirements in the context of their significant social commitment to the advanced practice of the profession, a commitment that is closely related to leadership. We should also indicate that interpersonal relationships were improved, and that there was technological progress. Some CMNs mentioned an increase in their workload and reported experiencing burnout syndrome. We conclude that CMNs’ management of health care during the pandemic has been extraordinary, especially in regard to the most vulnerable populations of patients, including individuals with chronic diseases and institutionalized older adults, a fact that has been valued by the institutions and by society in general. Full article
(This article belongs to the Special Issue Nursing Care and Clinical Management in the Post-Pandemic Era)
27 pages, 4518 KiB  
Review
The Impurity Removal and Comprehensive Utilization of Phosphogypsum: A Review
by Qingjun Guan, Zhuang Wang, Fujia Zhou, Weijian Yu, Zhigang Yin, Zhenyue Zhang, Ru’an Chi and Juncheng Zhou
Materials 2024, 17(9), 2067; https://doi.org/10.3390/ma17092067 (registering DOI) - 28 Apr 2024
Abstract
Phosphogypsum (PG), a byproduct during the phosphoric acid production process, also known as the wet process, contains complex and diverse impurities, resulting in low utilization and considerable accumulation. This leads to a massive waste of land resources and a series of environmental pollution [...] Read more.
Phosphogypsum (PG), a byproduct during the phosphoric acid production process, also known as the wet process, contains complex and diverse impurities, resulting in low utilization and considerable accumulation. This leads to a massive waste of land resources and a series of environmental pollution problems. Given the current urgent ecological and environmental situation, developing impurity removal processes with low energy consumption and high efficiency, exploring valuable resource recovery, preparing high value-added PG products, and broadening the comprehensive utilization ways of PG are significant strategies to promote the sustainable consumption of PG and sustainable development of the phosphorus chemical industry. This review comprehensively summarizes the advantages and disadvantages of existing PG impurity removal and utilization technologies and probes into the future development direction, which provides references and ideas for subsequent PG research. Full article
(This article belongs to the Section Construction and Building Materials)
17 pages, 1246 KiB  
Systematic Review
Influence of Immediate Dentin Sealing on Bond Strength of Resin-Based CAD/CAM Restoratives to Dentin: A Systematic Review of In Vitro Studies
by Iliana Antoniou, Petros Mourouzis, Dimitrios Dionysopoulos, Panagiotis Pandoleon and Kosmas Tolidis
Biomimetics 2024, 9(5), 267; https://doi.org/10.3390/biomimetics9050267 (registering DOI) - 28 Apr 2024
Abstract
Immediate dentin sealing (IDS) is a method of improving the bond strength of indirect dental restorative materials to dentin and belongs to the biomimetic protocols of contemporary dentistry. The purpose of this systematic review was to evaluate the effect of IDS on the [...] Read more.
Immediate dentin sealing (IDS) is a method of improving the bond strength of indirect dental restorative materials to dentin and belongs to the biomimetic protocols of contemporary dentistry. The purpose of this systematic review was to evaluate the effect of IDS on the bond strength of resin-based CAD/CAM materials to dentin. PubMed and MEDLINE, Scopus, and the Web of Science were searched by two individual researchers, namely for studies that have been published in English between 1 January 2005 and 1 October 2022 in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. The inclusion criteria encompassed articles related to in vitro studies, measuring the bond strength through microtensile bond strength (μ-TBS), micro-shear bond strength (μ-SBS), tensile bond strength (TBS) or shear bond strength (SBS) tests after the use of the IDS technique. The included restorative materials comprised resin-based CAD/CAM materials bonded to dentin. A total of 1821 studies were identified, of which 7 met the inclusion criteria. A meta-analysis was not deemed appropriate due to the high level of diversity inthe publications and techniques. The use of IDS yielded higher bond strength outcomesin various experimental conditions and resin-based CAD/CAM materials. Overall, IDS in CAD/CAM restorations may contribute to better clinical outcomesand improved restoration longevity due to this property. Full article
(This article belongs to the Special Issue Advances in Bioceramics for Bone Regeneration)
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16 pages, 1202 KiB  
Article
Exploring Attitudes toward Sustainability Education in a Group of Italian Preservice Teachers: The Role of Environmental Identity and Sense of Community Responsibility
by Francesco Sulla, Stefania Fantinelli, Giusi Antonia Toto, Guendalina Peconio and Ciro Esposito
Soc. Sci. 2024, 13(5), 241; https://doi.org/10.3390/socsci13050241 (registering DOI) - 28 Apr 2024
Abstract
In the current educational context, international institutions are being called to rethink education and declining new strategies that aim to teach sustainable behaviors. From this perspective, the present study aims to investigate the attitudes towards the sustainability of trainee teachers, verifying their connection [...] Read more.
In the current educational context, international institutions are being called to rethink education and declining new strategies that aim to teach sustainable behaviors. From this perspective, the present study aims to investigate the attitudes towards the sustainability of trainee teachers, verifying their connection with psycho-social variables, such as environmental identity and sense of community responsibility, and exploring their most common dispositions. In total, 126 Italian preservice teachers were involved in a mixed method study where they were asked to complete a questionnaire and participated in focus groups. The use of a combination of quantitative–qualitative methodologies has allowed us to obtain in-depth information about sustainability education. Quantitative data showed a virtuous circular relationship between environmental identity, attitudes towards education for sustainability, and the sense of community responsibility. Qualitative data showed the high frequency of two key action verbs, avoid and respect, but no specific reference to the educational field. After creating the target concept ‘to teach’, we observed a worrying absence of lemmas related to emotional dimension, and that the communication perspective is set on adults’ point of view, rather than on pupils. Limitations, strengths, and practical implications have been extensively discussed, especially in relation to the field of teacher education. Full article
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11 pages, 653 KiB  
Article
DEXA Body Composition Asymmetry Analysis and Association to Injury Risk and Low Back Pain in University Soccer Players
by Nicolas Vaillancourt, Chanelle Montpetit, Victoria Carile and Maryse Fortin
Int. J. Environ. Res. Public Health 2024, 21(5), 559; https://doi.org/10.3390/ijerph21050559 (registering DOI) - 28 Apr 2024
Abstract
Soccer is a laterally dominant sport owing to the repetitive nature of unilateral kicking. The relationship between functional and body composition asymmetries related to limb dominance in soccer players has yet to be established. When present, asymmetries can increase the risk of injury [...] Read more.
Soccer is a laterally dominant sport owing to the repetitive nature of unilateral kicking. The relationship between functional and body composition asymmetries related to limb dominance in soccer players has yet to be established. When present, asymmetries can increase the risk of injury and low back pain. Our study investigated whether lateral dominance is associated with limb asymmetries in a comprehensive body composition assessment among varsity soccer players. Twenty-seven varsity soccer players (age 20.4 ± 1.7 years old; BMI 22.6 ± 4.6 kg/m2) participated in this study. Body composition was assessed through dual-energy X-ray absorptiometry scans. Results showed low lower limb asymmetry indices in both males (3.82%) and females (3.36%) compared to normal ranges. However, upper limb lean mass exhibited high asymmetry, surpassing thresholds in males (7.3%) and females (4.39%). Significant differences were found in total bone mass among males and total lean body mass among females. Male players exhibited higher asymmetry indices in both arm and trunk mass compared to females. Despite these asymmetries, no significant correlations were found between asymmetry indices and occurrences of lower limb injury or low back pain. The study suggests that while evaluating body composition for injury prevention in soccer shows potential, lateral dominance may be influenced by factors extending beyond sport-specific adaptations. Full article
(This article belongs to the Special Issue Exercise Injury and Rehabilitation)
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14 pages, 311 KiB  
Article
Intrinsic Information-Theoretic Models
by D. Bernal-Casas and J. M. Oller
Entropy 2024, 26(5), 370; https://doi.org/10.3390/e26050370 (registering DOI) - 28 Apr 2024
Abstract
With this follow-up paper, we continue developing a mathematical framework based on information geometry for representing physical objects. The long-term goal is to lay down informational foundations for physics, especially quantum physics. We assume that we can now model information sources as univariate [...] Read more.
With this follow-up paper, we continue developing a mathematical framework based on information geometry for representing physical objects. The long-term goal is to lay down informational foundations for physics, especially quantum physics. We assume that we can now model information sources as univariate normal probability distributions N(μ,σ0), as before, but with a constant σ0 not necessarily equal to 1. Then, we also relaxed the independence condition when modeling m sources of information. Now, we model m sources with a multivariate normal probability distribution Nm(μμμ,ΣΣΣ0) with a constant variance–covariance matrix ΣΣΣ0 not necessarily diagonal, i.e., with covariance values different to 0, which leads to the concept of modes rather than sources. Invoking Schrödinger’s equation, we can still break the information into m quantum harmonic oscillators, one for each mode, and with energy levels independent of the values of σ0, altogether leading to the concept of “intrinsic”. Similarly, as in our previous work with the estimator’s variance, we found that the expectation of the quadratic Mahalanobis distance to the sample mean equals the energy levels of the quantum harmonic oscillator, being the minimum quadratic Mahalanobis distance at the minimum energy level of the oscillator and reaching the “intrinsic” Cramér–Rao lower bound at the lowest energy level. Also, we demonstrate that the global probability density function of the collective mode of a set of m quantum harmonic oscillators at the lowest energy level still equals the posterior probability distribution calculated using Bayes’ theorem from the sources of information for all data values, taking as a prior the Riemannian volume of the informative metric. While these new assumptions certainly add complexity to the mathematical framework, the results proven are invariant under transformations, leading to the concept of “intrinsic” information-theoretic models, which are essential for developing physics. Full article
22 pages, 2471 KiB  
Article
Performance of Recycled Polylactic Acid/Amorphous Polyhydroxyalkanoate Blends
by Simran Chatrath, Mansour Alotaibi and Carol Forance Barry
Polymers 2024, 16(9), 1230; https://doi.org/10.3390/polym16091230 (registering DOI) - 28 Apr 2024
Abstract
Blends of polylactic acid (PLA) with amorphous polyhydroxyalkanoate (aPHA) are less brittle than neat PLA, thus enabling their use as biodegradable packaging. This work investigated the impact of recycling on the properties of neat PLA and PLA/aPHA blends with 90 and 75 wt. [...] Read more.
Blends of polylactic acid (PLA) with amorphous polyhydroxyalkanoate (aPHA) are less brittle than neat PLA, thus enabling their use as biodegradable packaging. This work investigated the impact of recycling on the properties of neat PLA and PLA/aPHA blends with 90 and 75 wt. % PLA. After the materials were subjected to five heat histories in a single-screw extruder, the mechanical, rheological, and thermal properties were measured. All recycled compounds with 100% PLA and 75% PLA had similar decomposition behavior, whereas the decomposition temperatures for the blends with 90% PLA decreased with each additional heat cycle. The glass transition and melting temperatures were not impacted by reprocessing, but the crystallinity increased with more heat cycles. The complex viscosity of the reprocessed PLA and PLA/aPHA blends was much lower than for the neat PLA and increasing the number of heat cycles produced smaller reductions in the complex viscosity of 100% PLA and the blend with 90% PLA; no change in complex viscosity was observed for blends with 75% PLA exposed to 2 to 5 heat cycles. The tensile properties were not affected by reprocessing, whereas the impact strength for the 75% PLA blend decreased with reprocessing. These properties suggest that users will be able to incorporate scrap into the neat resin for thermoformed packaging. Full article
(This article belongs to the Special Issue Advanced Polymeric Materials: Structure Property Relationships)
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18 pages, 5462 KiB  
Article
Research on Power Optimization for Energy System of Hydrogen Fuel Cell Wheel-Driven Electric Tractor
by Jingyun Zhang, Buyuan Wang, Junjiang Zhang, Liyou Xu and Kai Zhang
World Electr. Veh. J. 2024, 15(5), 188; https://doi.org/10.3390/wevj15050188 (registering DOI) - 28 Apr 2024
Abstract
Hydrogen fuel cell tractors are emerging as a new power source for tractors. Currently, there is no mature energy management control method available. Existing methods mostly rely on engineers’ experience to determine the output power of the fuel cell and the power battery, [...] Read more.
Hydrogen fuel cell tractors are emerging as a new power source for tractors. Currently, there is no mature energy management control method available. Existing methods mostly rely on engineers’ experience to determine the output power of the fuel cell and the power battery, resulting in relatively low energy utilization efficiency of the energy system. To address the aforementioned problems, a power optimization method for the energy system of hydrogen fuel cell wheel-driven electric tractor was proposed. A dynamic model of tractor ploughing conditions was established based on the system dynamics theory. From this, based on the equivalent hydrogen consumption theory, the charging and discharging of the power battery were equivalent to the fuel consumption of the hydrogen fuel cell, forming an equivalent hydrogen consumption model for the tractor. Using the state of charge (SOC) of the power battery as a constraint, and with the minimum equivalent hydrogen consumption as the objective function, an instantaneously optimized power allocation method based on load demand in the energy system is proposed by using a traversal algorithm. The optimization method was simulated and tested based on the MATLAB simulation platform, and the results showed under ploughing conditions, compared with the rule-based control strategy, the proposed energy system power optimization method optimized the power output of hydrogen fuel cells and power batteries, allowing the energy system to work in a high-efficiency range, reducing the equivalent hydrogen consumption of the tractor by 7.79%, and solving the energy system power distribution problem. Full article
(This article belongs to the Special Issue New Energy Special Vehicle, Tractor and Agricultural Machinery)
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21 pages, 1441 KiB  
Review
NMR Spectroscopy in Diagnosis and Monitoring of Methylmalonic and Propionic Acidemias
by Calin Deleanu and Alina Nicolescu
Biomolecules 2024, 14(5), 528; https://doi.org/10.3390/biom14050528 (registering DOI) - 28 Apr 2024
Abstract
Although both localized nuclear magnetic resonance spectroscopy (MRS) and non-localized nuclear magnetic resonance spectroscopy (NMR) generate the same information, i.e., spectra generated by various groups from the structure of metabolites, they are rarely employed in the same study or by the same research [...] Read more.
Although both localized nuclear magnetic resonance spectroscopy (MRS) and non-localized nuclear magnetic resonance spectroscopy (NMR) generate the same information, i.e., spectra generated by various groups from the structure of metabolites, they are rarely employed in the same study or by the same research group. As our review reveals, these techniques have never been applied in the same study of methylmalonic acidemia (MMA), propionic acidemia (PA) or vitamin B12 deficiency patients. On the other hand, MRS and NMR provide complementary information which is very valuable in the assessment of the severity of disease and efficiency of its treatment. Thus, MRS provides intracellular metabolic information from localized regions of the brain, while NMR provides extracellular metabolic information from biological fluids like urine, blood or cerebrospinal fluid. This paper presents an up-to-date review of the NMR and MRS studies reported to date for methylmalonic and propionic acidemias. Vitamin B12 deficiency, although in most of its cases not inherited, shares similarities in its metabolic effects with MMA and it is also covered in this review. Full article
(This article belongs to the Collection Metabolomics and Integrated Multi-Omics in Health and Disease)
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39 pages, 2701 KiB  
Review
Recent Advances in the Field of Amino Acid-Conjugated Aminoferrocenes—A Personal Perspective
by Mojca Čakić Semenčić, Monika Kovačević and Lidija Barišić
Int. J. Mol. Sci. 2024, 25(9), 4810; https://doi.org/10.3390/ijms25094810 (registering DOI) - 28 Apr 2024
Abstract
The development of turn-based inhibitors of protein–protein interactions has attracted considerable attention in medicinal chemistry. Our group has synthesized a series of peptides derived from an amino-functionalized ferrocene to investigate their potential to mimic protein turn structures. Detailed DFT and spectroscopic studies (IR, [...] Read more.
The development of turn-based inhibitors of protein–protein interactions has attracted considerable attention in medicinal chemistry. Our group has synthesized a series of peptides derived from an amino-functionalized ferrocene to investigate their potential to mimic protein turn structures. Detailed DFT and spectroscopic studies (IR, NMR, CD) have shown that, for peptides, the backbone chirality and bulkiness of the amino acid side chains determine the hydrogen-bond pattern, allowing tuning of the size of the preferred hydrogen-bonded ring in turn-folded structures. However, their biological potential is more dependent on their lipophilicity. In addition, our pioneering work on the chiroptical properties of aminoferrocene-containing peptides enables the correlation of their geometry with the sign of the CD signal in the absorption region of the ferrocene chromophore. These studies have opened up the possibility of using aminoferrocene and its derivatives as chirooptical probes for the determination of various chirality elements, such as the central chirality of amino acids and the helicity of peptide sequences. Full article
28 pages, 758 KiB  
Article
Maximizing Net Present Value for Resource Constraint Project Scheduling Problems with Payments at Event Occurrences Using Approximate Dynamic Programming
by Tshewang Phuntsho and Tad Gonsalves
Algorithms 2024, 17(5), 180; https://doi.org/10.3390/a17050180 (registering DOI) - 28 Apr 2024
Abstract
Resource Constraint Project Scheduling Problems with Discounted Cash Flows (RCPSPDC) focuses on maximizing the net present value by summing the discounted cash flows of project activities. An extension of this problem is the Payment at Event Occurrences (PEO) scheme, where the client makes [...] Read more.
Resource Constraint Project Scheduling Problems with Discounted Cash Flows (RCPSPDC) focuses on maximizing the net present value by summing the discounted cash flows of project activities. An extension of this problem is the Payment at Event Occurrences (PEO) scheme, where the client makes multiple payments to the contractor upon completion of predefined activities, with additional final settlement at project completion. Numerous approximation methods such as metaheuristics have been proposed to solve this NP-hard problem. However, these methods suffer from parameter control and/or the computational cost of correcting infeasible solutions. Alternatively, approximate dynamic programming (ADP) sequentially generates a schedule based on strategies computed via Monte Carlo (MC) simulations. This saves the computations required for solution corrections, but its performance is highly dependent on its strategy. In this study, we propose the hybridization of ADP with three different metaheuristics to take advantage of their combined strengths, resulting in six different models. The Estimation of Distribution Algorithm (EDA) and Ant Colony Optimization (ACO) were used to recommend policies for ADP. A Discrete cCuckoo Search (DCS) further improved the schedules generated by ADP. Our experimental analysis performed on the j30, j60, and j90 datasets of PSPLIB has shown that ADP–DCS is better than ADP alone. Implementing the EDA and ACO as prioritization strategies for Monte Carlo simulations greatly improved the solutions with high statistical significance. In addition, models with the EDA showed better performance than those with ACO and random priority, especially when the number of events increased. Full article
13 pages, 799 KiB  
Article
Effect of Mat Pilates Training on Blood Pressure, Inflammatory, and Oxidative Profiles in Hypertensive Elderly
by Chutima Woramontri, Rungchai Chaunchaiyakul, Ai-Lun Yang, Yi-Yuan Lin and Kunanya Masodsai
Sports 2024, 12(5), 120; https://doi.org/10.3390/sports12050120 (registering DOI) - 28 Apr 2024
Abstract
To determine the effects of mat Pilates training on blood pressure, inflammatory, and antioxidative markers in hypertensive elderly people, 34 hypertensive subjects aged 60–75 years were randomly divided into a control group (CON; n = 17) and a mat Pilates training group (MP; [...] Read more.
To determine the effects of mat Pilates training on blood pressure, inflammatory, and antioxidative markers in hypertensive elderly people, 34 hypertensive subjects aged 60–75 years were randomly divided into a control group (CON; n = 17) and a mat Pilates training group (MP; n = 17). The CON participants conducted normal daily activities and participated in neither organized exercises nor sports training, while those in the MP group received mat Pilates training for 60 min three times/week for 12 weeks. Parameters including blood pressure, cardiovascular function, nitric oxide (NO), tumor necrotic factor-alpha (TNF-α), superoxide dismutase (SOD), and malonaldehyde (MDA) were collected at baseline and the end of 12 weeks. The MP group had significantly decreased blood pressure, improved cardiovascular variables, decreased MDA and TNF-α, and increased NO and SOD compared with the CON group and the pre-training period (p < 0.05). In conclusion, these findings demonstrate the positive effects of 12 weeks of mat Pilates training in terms of reducing blood pressure and increasing blood flow related to improvements in anti-inflammatory and antioxidative markers in hypertensive elderly people. Mat Pilates training might be integrated as an alternative therapeutic exercise modality in clinical practice for hypertensive elderly individuals. Full article
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30 pages, 357 KiB  
Article
A New Robust Iterative Scheme Applied in Solving a Fractional Diffusion Model for Oxygen Delivery via a Capillary of Tissues
by Godwin Amechi Okeke, Akanimo Victor Udo, Nadiyah Hussain Alharthi and Rubayyi T. Alqahtani
Mathematics 2024, 12(9), 1339; https://doi.org/10.3390/math12091339 (registering DOI) - 28 Apr 2024
Abstract
In this paper, we constructed a new and robust fixed point iterative scheme called the UO iterative scheme for the approximation of a contraction mapping. The scheme converges strongly to the fixed point of a contraction mapping. A rate of convergence result is [...] Read more.
In this paper, we constructed a new and robust fixed point iterative scheme called the UO iterative scheme for the approximation of a contraction mapping. The scheme converges strongly to the fixed point of a contraction mapping. A rate of convergence result is shown with an example, and our scheme, when compared, converges faster than some existing iterative schemes in the literature. Furthermore, the stability and data dependence results are shown. Our new scheme is applied in the approximation of the solution to the oxygen diffusion model. Finally, our results are applied in the approximation of the solution to the boundary value problems using Green’s functions with an example. Full article
(This article belongs to the Special Issue Variational Inequality and Mathematical Analysis)

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