The 2023 MDPI Annual Report has
been released!
 
16 pages, 1562 KiB  
Article
Evaluating Drug Interactions between Ritonavir and Opioid Analgesics: Implications from Physiologically Based Pharmacokinetic Simulation
by Liang Ni, Zhihai Cao, Jiakang Jiang, Wei Zhang, Wei Hu, Qian Zhang, Chaozhuang Shen, Xijing Chen and Liang Zheng
Pharmaceuticals 2024, 17(5), 640; https://doi.org/10.3390/ph17050640 (registering DOI) - 15 May 2024
Abstract
Several commonly used opioid analgesics, such as fentanyl, sufentanil, alfentanil, and hydrocodone, are by report primarily metabolized by the CYP3A4 enzyme. The concurrent use of ritonavir, a potent CYP3A4 inhibitor, can lead to significant drug interactions. Using physiologically based pharmacokinetic (PBPK) modeling and [...] Read more.
Several commonly used opioid analgesics, such as fentanyl, sufentanil, alfentanil, and hydrocodone, are by report primarily metabolized by the CYP3A4 enzyme. The concurrent use of ritonavir, a potent CYP3A4 inhibitor, can lead to significant drug interactions. Using physiologically based pharmacokinetic (PBPK) modeling and simulation, this study examines the effects of different dosing regimens of ritonavir on the pharmacokinetics of these opioids. The findings reveal that co-administration of ritonavir significantly increases the exposure of fentanyl analogs, with over a 10-fold increase in the exposure of alfentanil and sufentanil when given with ritonavir. Conversely, the effect of ritonavir on fentanyl exposure is modest, likely due to additional metabolism pathways. Additionally, the study demonstrates that the steady-state exposure of hydrocodone and its active metabolite hydromorphone can be increased by up to 87% and 95%, respectively, with concurrent use of ritonavir. The extended-release formulation of hydrocodone is particularly affected. These insights from PBPK modeling provide valuable guidance for optimizing opioid dosing and minimizing the risk of toxicity when used in combination with ritonavir-containing prescriptions. Full article
(This article belongs to the Special Issue Population Pharmacokinetic and Pharmacodynamics)
16 pages, 1472 KiB  
Article
Deficit Irrigation-Based Improvement in Growth and Yield of Quinoa in the Northwestern Arid Region in China
by Mukeran Awa, Jinghua Zhao and Hudan Tumaerbai
Sustainability 2024, 16(10), 4136; https://doi.org/10.3390/su16104136 (registering DOI) - 15 May 2024
Abstract
Given the current global water scarcity issues, which particularly affect arid regions such as northwestern China, it is crucial to find crop planting patterns that result in efficient water resource utilization. Quinoa, as a drought-resistant and highly nutritious crop, has garnered significant attention [...] Read more.
Given the current global water scarcity issues, which particularly affect arid regions such as northwestern China, it is crucial to find crop planting patterns that result in efficient water resource utilization. Quinoa, as a drought-resistant and highly nutritious crop, has garnered significant attention from agricultural researchers in recent years. From 2019 to 2020, a series of experimental studies were conducted under non-mulching drip irrigation conditions to investigate the growth adaptability and the response to different irrigation levels of quinoa in an arid region in northwestern China. A comparative analysis of quinoa’s dry matter accumulation, yield, thousand-grain weight, harvest index, and water use efficiency under varying irrigation levels revealed that increasing irrigation significantly enhanced quinoa’s dry matter accumulation and yield. By optimizing the irrigation strategies, we found that the water-saving practice of initiating moderate irrigation in the sensitive water-demanding stages (flowering and fruiting) of quinoa increased the yield. The experiment results showed that, in 2020, the optimal irrigation amount was 3675 m3·ha−1 during a 14-day irrigation cycle, meeting quinoa’s growth requirements while improving water resource utilization efficiency. This study not only provides a scientific basis for the efficient cultivation of quinoa in the arid regions of northwestern China, but also offers new insights into and technical support for agricultural water resource management in the region, contributing to the sustainable development of agriculture in arid areas. Full article
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15 pages, 556 KiB  
Article
Analysis of IL-17A, IL-17F, and miR-146a-5p Prior to Transplantation and Their Role in Kidney Transplant Recipients
by Barbara Wysoczańska, Marta Dratwa, Artur Nieszporek, Wanda Niepiekło-Miniewska, Dorota Kamińska, Tomasz Ramuś, Julia Rasała, Magdalena Krajewska and Katarzyna Bogunia-Kubik
J. Clin. Med. 2024, 13(10), 2920; https://doi.org/10.3390/jcm13102920 (registering DOI) - 15 May 2024
Abstract
Background/Objectives: The balance between regulatory and Th17 cells plays an important role in maintaining the immune tolerance after kidney transplantation (KTx) which is essential for transplantation success, defined as a long graft survival and an absence of organ rejection. The present study [...] Read more.
Background/Objectives: The balance between regulatory and Th17 cells plays an important role in maintaining the immune tolerance after kidney transplantation (KTx) which is essential for transplantation success, defined as a long graft survival and an absence of organ rejection. The present study aimed to assess whether the pretransplant characteristics of IL-17A and IL-17F, their receptors, as well as miR-146a-5p, an miRNA associated with IL-17A/F regulation, can predict KTx outcomes. Methods: A group of 108 pre-KTx dialysis patients and 125 healthy controls were investigated for single nucleotide substitutions within genes coding for IL-17A, IL-17F, their IL-17RA/RC receptors, and miR-146a-5p. Genotyping was performed using LightSNiP assays. In addition, IL17-A/F serum concentrations were determined using ELISA while miR-146a-5p expression was analyzed by RT-PCR. Results: The IL-17F (rs763780) G allele prevailed in KTx recipients as compared to healthy individuals (OR = 23.59, p < 0.0001) and was associated with a higher IL-17F serum level (p = 0.0381) prior to transplantation. Higher miR-146a-5p expression before KTx was more frequently detected in recipients with an increased IL-17A serum concentration (p = 0.0177). Moreover, IL-17A (rs2275913) GG homozygosity was found to be associated with an increased incidence of deaths before KTx (OR = 4.17, p = 0.0307). T-cell or acute rejection episodes were more frequently observed among patients with the C allele of miR-146a-5p (rs2910164) (OR = 5.38, p = 0.0531). IL17-RA/-RC genetic variants (p < 0.05) seem to be associated with eGFR values. Conclusions: These results imply that IL-17F (rs763780) polymorphism is associated with the serum level of this cytokine and may be related to the risk of renal disease and transplant rejection together with miR-146a-5p (rs2910164), while the IL-17A (rs2275913) genotype may affect patients’ survival before KTx. Full article
(This article belongs to the Section Nephrology & Urology)
19 pages, 3688 KiB  
Article
Beyond Static Obstacles: Integrating Kalman Filter with Reinforcement Learning for Drone Navigation
by Francesco Marino and Giorgio Guglieri
Aerospace 2024, 11(5), 395; https://doi.org/10.3390/aerospace11050395 (registering DOI) - 15 May 2024
Abstract
Autonomous drones offer immense potential in dynamic environments, but their navigation systems often struggle with moving obstacles. This paper presents a novel approach for drone trajectory planning in such scenarios, combining the Interactive Multiple Model (IMM) Kalman filter with Proximal Policy Optimization (PPO) [...] Read more.
Autonomous drones offer immense potential in dynamic environments, but their navigation systems often struggle with moving obstacles. This paper presents a novel approach for drone trajectory planning in such scenarios, combining the Interactive Multiple Model (IMM) Kalman filter with Proximal Policy Optimization (PPO) reinforcement learning (RL). The IMM Kalman filter addresses state estimation challenges by modeling the potential motion patterns of moving objects. This enables accurate prediction of future object positions, even in uncertain environments. The PPO reinforcement learning algorithm then leverages these predictions to optimize the drone’s real-time trajectory. Additionally, the capability of PPO to work with continuous action spaces makes it ideal for the smooth control adjustments required for safe navigation. Our simulation results demonstrate the effectiveness of this combined approach. The drone successfully navigates complex dynamic environments, achieving collision avoidance and goal-oriented behavior. This work highlights the potential of integrating advanced state estimation and reinforcement learning techniques to enhance autonomous drone capabilities in unpredictable settings. Full article
21 pages, 10528 KiB  
Article
Ozone-Assisted Hydrothermal Synthesis Method of Sb-Doped SnO2 Conductive Nanoparticles for Carbon-Free Oxygen-Reduction-Reaction Catalysts of Proton-Exchange-Membrane Hydrogen Fuel Cells
by Takeshi Fukuda, Kenji Iimura, Takanori Yamamoto, Ryuki Tsuji, Maito Tanabe, Seiji Nakashima, Naoki Fukumuro and Seigo Ito
Crystals 2024, 14(5), 462; https://doi.org/10.3390/cryst14050462 (registering DOI) - 15 May 2024
Abstract
Proton-exchange-membrane hydrogen fuel cells (PEMFCs) are an important energy device for achieving a sustainable hydrogen society. Carbon-based catalysts used in PEMFCs’ cathode can degrade significantly during operation-voltage shifts due to the carbon deterioration. The longer lifetime of the system is necessary for the [...] Read more.
Proton-exchange-membrane hydrogen fuel cells (PEMFCs) are an important energy device for achieving a sustainable hydrogen society. Carbon-based catalysts used in PEMFCs’ cathode can degrade significantly during operation-voltage shifts due to the carbon deterioration. The longer lifetime of the system is necessary for the further wide commercialization of PEMFCs. Therefore, carbon-free catalysts are required for PEMFCs. In this study, highly crystallized conducting Sb-doped SnO2 (Sb-SnO2) nanoparticles (smaller than 7 nm in size) were synthesized using an ozone-assisted hydrothermal synthesis. Pt nanoparticles were loaded on Sb-SnO2 supporting particles by polyol method to be “Pt/Sb-SnO2 catalyst”. The Pt/Sb-SnO2 catalyst showed a high oxygen reduction reaction (ORR) mass activity (178.3 A g−1-Pt @ 0.9 V), compared to Pt/C (149.3 A g−1-Pt @ 0.9 V). In addition, the retention ratio from the initial value of electrochemical surface area (ECSA) during 100,000-voltage cycles tests between 1.0 V and 1.5 V, Pt/SnO2 and Pt/Sb-SnO2 catalyst exhibited higher stability (90% and 80%), respectively, than that of Pt/C catalyst (47%). Therefore, the SnO2 and Sb-SnO2 nanoparticles synthesized using this new ozone-assisted hydrothermal method are promising as carbon-free catalyst supports for PEMFCs. Full article
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30 pages, 3587 KiB  
Review
Literature Review on Conjugated Polymers as Light-Sensitive Materials for Photovoltaic and Light-Emitting Devices in Photonic Biomaterial Applications
by Paolo Coghi and Carmine Coluccini
Polymers 2024, 16(10), 1407; https://doi.org/10.3390/polym16101407 (registering DOI) - 15 May 2024
Abstract
Due to their extended p-orbital delocalization, conjugated polymers absorb light in the range of visible–NIR frequencies. We attempt to exploit this property to create materials that compete with inorganic semiconductors in photovoltaic and light-emitting materials. Beyond competing for applications in photonic devices, organic [...] Read more.
Due to their extended p-orbital delocalization, conjugated polymers absorb light in the range of visible–NIR frequencies. We attempt to exploit this property to create materials that compete with inorganic semiconductors in photovoltaic and light-emitting materials. Beyond competing for applications in photonic devices, organic conjugated compounds, polymers, and small molecules have also been extended to biomedical applications like phototherapy and biodetection. Recent research on conjugated polymers has focused on bioapplications based on the absorbed light energy conversions in electric impulses, chemical energy, heat, and light emission. In this review, we describe the working principles of those photonic devices that have been applied and researched in the field of biomaterials. Full article
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14 pages, 670 KiB  
Article
Eco-Friendly Smart Car Parking Management System with Enhanced Sustainability
by Nazmus Sakib, A. S. M. Bakibillah, Susilawati Susilawati, Md Abdus Samad Kamal and Kou Yamada
Sustainability 2024, 16(10), 4145; https://doi.org/10.3390/su16104145 (registering DOI) - 15 May 2024
Abstract
Efficient car parking management systems that minimize environmental impacts while maximizing user comfort are highly demanding for a future sustainable society. Using electric or gasoline vehicle-type information, emerging computation and communication technologies open the opportunity to provide practical solutions to achieve such goals. [...] Read more.
Efficient car parking management systems that minimize environmental impacts while maximizing user comfort are highly demanding for a future sustainable society. Using electric or gasoline vehicle-type information, emerging computation and communication technologies open the opportunity to provide practical solutions to achieve such goals. This paper proposes an eco-friendly smart parking management system that optimally allocates the incoming vehicles to reduce overall emissions in closed parking facilities while providing comfort incentives to the users of electric vehicles (EVs). Specifically, upon arrival of a car, the most suitable parking spot is determined by minimizing an adaptive objective function that indirectly reflects anticipatory operation for the overall performance maximization of the parking facility using electric or gasoline vehicle-type information. The adaptive objective function includes a trade-off factor that tunes driving and walking distances, relating emissions and comfort to treat incoming vehicles appropriately. The proposed system is simulated for managing a model car parking facility in a shopping complex in Japan, and the aspects related to fuel consumption, CO2 emissions, and user comfort are evaluated and benchmarked with other standard parking management systems. The proposed system reduces CO2 emissions and fuel consumption and improves parking efficiency compared to the current parking management systems, while also prioritizing user comfort. Full article
34 pages, 23312 KiB  
Article
ADPN Regulates Oxidative Stress-Induced Follicular Atresia in Geese by Modulating Granulosa Cell Apoptosis and Autophagy
by Yan Zheng, Yunqiao Qiu, Qianhui Wang, Ming Gao, Zhongzan Cao and Xinhong Luan
Int. J. Mol. Sci. 2024, 25(10), 5400; https://doi.org/10.3390/ijms25105400 (registering DOI) - 15 May 2024
Abstract
Geese are susceptible to oxidative stress during reproduction, which can lead to follicular atresia and impact egg production. Follicular atresia is directly triggered by the apoptosis and autophagy of granulosa cells (GCs). Adiponectin (ADPN), which is secreted by adipose tissue, has good antioxidant [...] Read more.
Geese are susceptible to oxidative stress during reproduction, which can lead to follicular atresia and impact egg production. Follicular atresia is directly triggered by the apoptosis and autophagy of granulosa cells (GCs). Adiponectin (ADPN), which is secreted by adipose tissue, has good antioxidant and anti-apoptotic capacity, but its role in regulating the apoptosis of GCs in geese is unclear. To investigate this, this study examined the levels of oxidative stress, apoptosis, and autophagy in follicular tissues and GCs using RT-qPCR, Western blotting, immunofluorescence, flow cytometry, transcriptomics and other methods. Atretic follicles exhibited high levels of oxidative stress and apoptosis, and autophagic flux was obstructed. Stimulating GCs with H2O2 produced results similar to those of atretic follicles. The effects of ADPN overexpression and knockdown on oxidative stress, apoptosis and autophagy in GCs were investigated. ADPN was found to modulate autophagy and reduced oxidative stress and apoptosis in GCs, in addition to protecting them from H2O2-induced damage. These results may provide a reasonable reference for improving egg-laying performance of geese. Full article
(This article belongs to the Section Molecular Biology)
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20 pages, 3613 KiB  
Article
A Systematic Formulation into Neutrosophic Z Methodologies for Symmetrical and Asymmetrical Transportation Problem Challenges
by Muhammad Kamran, Manal Elzain Mohamed Abdalla, Muhammad Nadeem, Anns Uzair, Muhammad Farman, Lakhdar Ragoub and Ismail Naci Cangul
Symmetry 2024, 16(5), 615; https://doi.org/10.3390/sym16050615 (registering DOI) - 15 May 2024
Abstract
This study formulates a multi-objective, multi-item solid transportation issue with parameters that are neutrosophic Z-number fuzzy variables such as transportation costs, supplies, and demands. This work covers two scenarios where uncertainty in the problem can arise: the fuzzy solid transportation problem and the [...] Read more.
This study formulates a multi-objective, multi-item solid transportation issue with parameters that are neutrosophic Z-number fuzzy variables such as transportation costs, supplies, and demands. This work covers two scenarios where uncertainty in the problem can arise: the fuzzy solid transportation problem and the interval solid transportation problem. The first scenario arises when we represent data problems as intervals instead of exact values, while the second scenario arises when the information is not entirely clear. We address both models when the uncertainty alone impacts the constraint set. In order to find a solution for the interval case, we generate an additional problem. Since this auxiliary problem is typical of solid transportation, we can resolve it using the effective techniques currently in use. In the fuzzy scenario, a parametric method is used to discover a fuzzy solution to the earlier issue. Parametric analysis identifies that the best parameterized approaches to complementary problems are characterized by the application of parametric analysis. We present a suggested algorithm for determining the stability set. Finally, we provide a numerical example and sensitivity analysis for the transportation problem, which is both symmetrical and asymmetrical. Full article
(This article belongs to the Special Issue Symmetry/Asymmetry in Operations Research)
21 pages, 8106 KiB  
Article
One-Pot Synthesis of Functionalised rGO/AgNPs Hybrids as Pigments for Highly Conductive Printing Inks
by Vassiliki Belessi, Apostolos Koutsioukis, Dimitra Giasafaki, Theodora Philippakopoulou, Vassiliki Panagiotopoulou, Christina Mitzithra, Sotiria Kripotou, Georgios Manolis, Theodore Steriotis, Georgia Charalambopoulou and Vasilios Georgakilas
Nanomaterials 2024, 14(10), 859; https://doi.org/10.3390/nano14100859 (registering DOI) - 15 May 2024
Abstract
This work provides a method for the development of conductive water-based printing inks for gravure, flexography and screen-printing incorporating commercial resins that are already used in the printing industry. The development of the respective conductive materials/pigments is based on the simultaneous (in one [...] Read more.
This work provides a method for the development of conductive water-based printing inks for gravure, flexography and screen-printing incorporating commercial resins that are already used in the printing industry. The development of the respective conductive materials/pigments is based on the simultaneous (in one step) reduction of silver salts and graphene oxide in the presence of 2,5-diaminobenzenesulfonic acid that is used for the first time as the common in-situ reducing agent for these two reactions. The presence of aminophenylsulfonic derivatives is essential for the reduction procedure and in parallel leads to the enrichment of the graphene surface with aminophenylsulfonic groups that provide a high hydrophilicity to the final materials/pigments. Full article
(This article belongs to the Special Issue Nanomaterials-Based Functional Inks for Printing Applications)
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18 pages, 1116 KiB  
Review
Analysis and Applications of the Two Phases Closed Thermosyphon Technology in the Highways in Permafrost Regions: A Review
by Shuai Du and Zeliang Ye
Appl. Sci. 2024, 14(10), 4185; https://doi.org/10.3390/app14104185 (registering DOI) - 15 May 2024
Abstract
Permafrost spans approximately 23–25% of the land in the northern hemisphere, primarily found in Russia, Canada, USA, and China. Numerous engineering projects, particularly those related to transportation, are situated within these permafrost regions. Due to the impact of highway construction and global warming, [...] Read more.
Permafrost spans approximately 23–25% of the land in the northern hemisphere, primarily found in Russia, Canada, USA, and China. Numerous engineering projects, particularly those related to transportation, are situated within these permafrost regions. Due to the impact of highway construction and global warming, the permafrost beneath the infrastructure is deteriorating, leading to significant damage. Two phases closed thermosyphon (TPCT) is a widely accepted green countermeasure against the problem in permafrost regions. Although it has been applied to prevent permafrost degradation, their application presents significant challenges on account of the stronger endothermic action of asphalt pavement. This paper focused on a review of the thermosyphon technology and application in the permafrost. Moreover, the article highlighted the excellent working performance of the TPCT that improves the stability of the infrastructures and prevents it degrading due its excellent efficiency in terms of heat transfer. The industrial applications of the TPCT were also summarized, along with their limitations. Ultimately, the findings presented in this paper can offer crucial insights for future TPCT design and development in permafrost areas. Full article
(This article belongs to the Special Issue Geotechnical Engineering: Principles and Applications)
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41 pages, 9843 KiB  
Article
Urban Resilience Index for Critical Infrastructure: A Scenario-Based Approach to Disaster Risk Reduction in Road Networks
by Seyed M. H. S. Rezvani, Maria João Falcão Silva and Nuno Marques de Almeida
Sustainability 2024, 16(10), 4143; https://doi.org/10.3390/su16104143 (registering DOI) - 15 May 2024
Abstract
Floods pose a significant threat to road networks globally, disrupting transportation, isolating communities, and causing economic losses. This study proposes a four-stage methodology (avoidance, endurance, recovery, and adaptability) to enhance the resilience of road networks. We combine analysis of constructed assets and asset [...] Read more.
Floods pose a significant threat to road networks globally, disrupting transportation, isolating communities, and causing economic losses. This study proposes a four-stage methodology (avoidance, endurance, recovery, and adaptability) to enhance the resilience of road networks. We combine analysis of constructed assets and asset system performance with multiple disaster scenarios (Reactive Flood Response, Proactive Resilience Planning, and Early Warning Systems). Advanced flood Geospatial-AI models and open data sources pinpoint high-risk zones affecting crucial routes. The study investigates how resilient assets and infrastructure scenarios improve outcomes within Urban Resilience Index (CRI) planning, integrating performance metrics with cost–benefit analysis to identify effective and economically viable solutions. A case study on the Lisbon Road network subjected to flood risk analyzes the effectiveness and efficiency of these scenarios, through loss and gain cost analysis. Scenario 2, Proactive Resilience Planning, demonstrates a 7.6% increase compared to Scenario 1, Reactive Flood Response, and a 3.5% increase compared to Scenario 3, Early Warning Systems Implementation. By considering asset performance, risk optimization, and cost, the study supports resilient infrastructure strategies that minimize economic impacts, while enabling communities to withstand and recover from flood events. Integrating performance and cost–benefit analysis ensures the sustainability and feasibility of risk reduction measures. Full article
(This article belongs to the Topic Resilient Civil Infrastructure)
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23 pages, 1600 KiB  
Review
Gonadotropin-Releasing Hormone (GnRH) and Its Agonists in Bovine Reproduction I: Structure, Biosynthesis, Physiological Effects, and Its Role in Estrous Synchronization
by Eman M. Hassanein, Zoltán Szelényi and Ottó Szenci
Animals 2024, 14(10), 1473; https://doi.org/10.3390/ani14101473 (registering DOI) - 15 May 2024
Abstract
GnRH is essential for the regulation of mammalian reproductive processes. It regulates the production and release of pituitary gonadotropins, thereby influencing steroidogenesis and gametogenesis. While primarily produced in the hypothalamus, GnRH is also produced in peripheral organs, such as the gonads and placenta. [...] Read more.
GnRH is essential for the regulation of mammalian reproductive processes. It regulates the production and release of pituitary gonadotropins, thereby influencing steroidogenesis and gametogenesis. While primarily produced in the hypothalamus, GnRH is also produced in peripheral organs, such as the gonads and placenta. GnRH analogs, including agonists and antagonists, have been synthesized for the reproductive management of animals and humans. This review focuses on the functions of hypothalamic GnRH in the reproductive processes of cattle. In addition to inducing the surge release of LH, the pulsatile secretion of GnRH stimulates the pituitary gland to release FSH and LH, thereby regulating gonadal function. Various GnRH-based products have been synthesized to increase their potency and efficacy in regulating reproductive functions. This review article describes the chemical structures of GnRH and its agonists. This discussion extends to the gene expression of GnRH in the hypothalamus, highlighting its pivotal role in regulating the reproductive process. Furthermore, GnRH is involved in regulating ovarian follicular development and luteal phase support, and estrus synchronization is involved. A comprehensive understanding of the role of GnRH and its analogs in the modulation of reproductive processes is essential for optimizing animal reproduction. Full article
(This article belongs to the Special Issue Livestock Reproduction: Reproductive Technologies in Animal Science)
16 pages, 4103 KiB  
Article
Population Status of the Endangered Semi-Mangrove Dolichandrone spathacea on Hainan Island, China
by Mi Tian, Xinran Ke, Ming Li, Kaixuan Deng, Yong Yang, Zanshan Fang, Cairong Zhong, Shen Li, Zhengjie Zhu, Nora Fung-Yee Tam, Tao Lang and Haichao Zhou
Forests 2024, 15(5), 865; https://doi.org/10.3390/f15050865 (registering DOI) - 15 May 2024
Abstract
In China, Dolichandrone spathacea is a rare and endangered semi-mangrove plant species with an extremely small population, naturally distributed only in Zhanjiang City and the east coast of Hainan Island. Despite conservation concerns, the population status of D. spathacea has received [...] Read more.
In China, Dolichandrone spathacea is a rare and endangered semi-mangrove plant species with an extremely small population, naturally distributed only in Zhanjiang City and the east coast of Hainan Island. Despite conservation concerns, the population status of D. spathacea has received little scientific attention. In this study, we evaluated the current status of D. spathacea on Hainan Island, China, in order to propose sustainable conservation strategies for future ecological restoration of its natural population. D. spathacea on Hainan Island can be divided into four populations. All the D. spathacea populations present a state of overall dispersion, local concentration, and occasionally sporadic existence, and they exist in geographical isolation. The young, middle, and old D. spathacea plants account for 20.42%, 66.20%, and 13.38%, respectively, indicating that the D. spathacea population on Hainan Island is declining. Furthermore, instead of temporal structure, we used diameter at breast height (DBH) to establish a static life table, draw a population survival curve, and quantify the future development trend through population dynamic analysis and time-series prediction. These results suggest that the D. spathacea population in the Bamen Gulf (Wenchang) and Qingmei Harbor (Sanya) on Hainan Island is sensitive to external disturbances and possesses two main increases in mortality rate—namely, in its juvenile and mature stages—due to competition and anthropogenic interferences, which might be the most important reasons for its endangered status. Depending on the current conditions of the D. spathacea population, we should conserve and expand mature trees in situ, preserve their germplasm resources, rehabilitate their habitats to promote provenance restoration, and conduct artificial cultivation and spreading planting in order to realize the sustainable conservation and management of D. spathacea. Full article
(This article belongs to the Special Issue Effect of Mangrove Ecosystems on Coastal Ecology and Climate Change)
15 pages, 6936 KiB  
Article
Effect of Overheating on the Tensile Properties of Nickel-Based Superalloy GH4720Li
by Anqi Wang, Zhicheng Liu, Ruoyao Cui, Yangyang Wu, Di Zhang and Xiaogang Wang
Materials 2024, 17(10), 2351; https://doi.org/10.3390/ma17102351 (registering DOI) - 15 May 2024
Abstract
Aero-engines can be exposed to One Engine Inoperative (OEI) conditions during service, and the resulting overheating effect may significantly impact their structural integrity and flight safety. This paper focuses on the influence of overheating on the microstructural evolution and tensile properties of the [...] Read more.
Aero-engines can be exposed to One Engine Inoperative (OEI) conditions during service, and the resulting overheating effect may significantly impact their structural integrity and flight safety. This paper focuses on the influence of overheating on the microstructural evolution and tensile properties of the GH4720Li alloy, a nickel-based polycrystalline superalloy commonly used in turbine disks. Based on the typical OEI operating conditions of a real aero-engine, a series of non-isothermal high-temperature tensile tests involving an OEI stage of 800 °C were conducted. The effects of OEI-induced overheating on the microstructure and tensile properties of the GH4720Li alloy were investigated. The results showed that, after OEI treatment, the primary γ′ phase in this alloy was partially dissolved. The GH4720Li superalloy also exhibited numerous microcracks at the grain boundaries, resulting in complex effects on its tensile properties. The alloy’s yield strength and ultimate tensile strength were slightly decreased, whereas its ductility decreased considerably. The OEI-induced embrittlement phenomenon was mainly caused by the non-uniform distribution of the tertiary γ′ phase within grains. The formation of microcracks nucleated at the interfaces between the primary γ′ precipitates and γ matrix phase was another key factor. Full article
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19 pages, 2195 KiB  
Article
Improved Synthesis of Cu2O NPs and Ascorbic Acid-Modified Derivatives for Adsorption of Brilliant Cresyl Blue: Surface and Reusability Studies
by Saad Zeghdi, Salah Eddine Laouini, Hamdi Ali Mohammed, Abderrhmane Bouafia, Mohammed Laid Tedjani, Mahmood M. S. Abdullah and Tomasz Trzepieciński
Materials 2024, 17(10), 2358; https://doi.org/10.3390/ma17102358 (registering DOI) - 15 May 2024
Abstract
This study addresses the critical need for efficient and recyclable photocatalysts for water treatment applications by presenting a novel approach for the synthesis and characterization of copper (I) oxide (Cu2O) nanoparticles modified with ascorbic acid (Cu2O/AA). The motivation for [...] Read more.
This study addresses the critical need for efficient and recyclable photocatalysts for water treatment applications by presenting a novel approach for the synthesis and characterization of copper (I) oxide (Cu2O) nanoparticles modified with ascorbic acid (Cu2O/AA). The motivation for this research stems from the increasing concern about environmental pollution caused by organic pollutants, such as Brilliant Cresyl Blue (BCB), and the necessity for sustainable solutions to mitigate this issue. Through comprehensive characterization techniques including Ultraviolet–Visible spectroscopy (UV-Vis), Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), zeta potential measurements, and Brunauer–Emmett–Teller (BET) analysis, we demonstrate a significant modification to the electronic structure, enhancing the photocatalytic activity of Cu2O/AA. BET analysis revealed a mesoporous structure with a specific surface area of 2.7247 m2/g for Cu2O/AA, further emphasizing its potential for enhanced catalytic performance. The photocatalytic degradation studies showcased remarkable efficiency improvements, with degradation coefficients of 30.8% and 73.12% for Cu2O NPs and Cu2O/AA NC, respectively, within a 120 min timeframe. Additionally, recyclability experiments indicated sustained efficiency over five consecutive cycles, with both catalysts retaining crystalline integrity. These findings underscore the promising potential of Cu2O/AA nanoparticles as highly efficient and recyclable photocatalysts for the degradation of organic pollutants, offering superior performance compared to pure Cu2O NPs and addressing the pressing need for sustainable water treatment solutions. Full article
(This article belongs to the Section Advanced Nanomaterials and Nanotechnology)
18 pages, 3733 KiB  
Review
Historical Perspective and Current Trends in Anticancer Drug Development
by Katarzyna Gach-Janczak, Joanna Drogosz-Stachowicz, Anna Janecka, Karol Wtorek and Marek Mirowski
Cancers 2024, 16(10), 1878; https://doi.org/10.3390/cancers16101878 (registering DOI) - 15 May 2024
Abstract
Cancer is considered one of the leading causes of death in the 21st century. The intensive search for new anticancer drugs has been actively pursued by chemists and pharmacologists for decades, focusing either on the isolation of compounds with cytotoxic properties from plants [...] Read more.
Cancer is considered one of the leading causes of death in the 21st century. The intensive search for new anticancer drugs has been actively pursued by chemists and pharmacologists for decades, focusing either on the isolation of compounds with cytotoxic properties from plants or on screening thousands of synthetic molecules. Compounds that could potentially become candidates for new anticancer drugs must have the ability to inhibit proliferation and/or induce apoptosis in cancer cells without causing too much damage to normal cells. Some anticancer compounds were discovered by accident, others as a result of long-term research. In this review, we have presented a brief history of the development of the most important groups of anticancer drugs, pointing to the fact that they all have many side effects. Full article
(This article belongs to the Special Issue Feature Review for Cancer Therapy)
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17 pages, 1394 KiB  
Article
Exploring the Efficacy of Binary Surveys versus Likert Scales in Assessing Student Perspectives Using Bayesian Analysis
by Andrés Suárez-García, María Álvarez-Hernández, Elena Arce and José Roberto Ribas
Appl. Sci. 2024, 14(10), 4189; https://doi.org/10.3390/app14104189 (registering DOI) - 15 May 2024
Abstract
Likert-scale surveys are the undeniable protagonists of online evaluations. They ask the respondent to express their degree of agreement with a series of statements related to the development of a subject. In contrast, in social networks, dichotomous surveys are mostly used. They force [...] Read more.
Likert-scale surveys are the undeniable protagonists of online evaluations. They ask the respondent to express their degree of agreement with a series of statements related to the development of a subject. In contrast, in social networks, dichotomous surveys are mostly used. They force respondents to polarize their opinions by selecting “like” or “dislike”. This study compares the efficacy of binary and Likert surveys in gathering student opinions on mechanical engineering program subjects. Using Bayesian analysis, it analyzes the similarity of responses obtained from both formats. For each question and scale, the ratio of “I like” among the total responses collected was calculated. The Bayesian factor method was used to compare the ratios obtained. The null hypothesis was equality between the ratios obtained by the different scales for the same question. This hypothesis was rejected in only 7 of the 49 questions evaluated—less than 15%. Finally, the students were surveyed on the preference for use of both scales. More than 80% stated a preference for the use of the dichotomous format. In view of the results obtained, we recommend more frequent use of the dichotomous scale to gather students’ opinions. Full article
(This article belongs to the Special Issue Novel Applications of Machine Learning and Bayesian Optimization)
24 pages, 2540 KiB  
Article
Systematic Opportunity Scan of Energy Recovery Technologies Applied to Trucks with Electric Refrigerated Units
by Áquila Chagas de Carvalho, Matheus Henrique Rodrigues Miranda, Ludmila Corrêa de Alkmin e Silva, Fabrício Leonardo Silva, Rafael Rogora Kawano, Jony Javorski Eckert and Franco Giuseppe Dedini
Inventions 2024, 9(3), 58; https://doi.org/10.3390/inventions9030058 (registering DOI) - 15 May 2024
Abstract
This article presents an original research methodology that combines insights from patents and academic research, offering a unique perspective on energy recovery technologies for trucks equipped with refrigeration units. The purpose of the study is to perform a functional analysis of existing solutions [...] Read more.
This article presents an original research methodology that combines insights from patents and academic research, offering a unique perspective on energy recovery technologies for trucks equipped with refrigeration units. The purpose of the study is to perform a functional analysis of existing solutions and to suggest a mechanism for exposing unexplored areas and opportunities for innovation. To achieve this goal, a systematic opportunity scan is presented, investigating patents and conducting a state-of-the-art search of existing technologies. This scan classifies a diverse range of solutions, elucidating their interconnections and providing an overview of the existing technological area, covering system components and technical trends. Thus, the main functions and components are listed, as well as the system requirements. Once the functions have been surveyed, a morphological matrix is proposed, and five main functions are analyzed. This methodology makes it possible to list the majority of the possible solutions for the functions analyzed, taking into account the components observed in the literature review and patents, including new components raised by the research group. Finally, with the morphological matrix structure, it was possible to combine unexplored elements, achieving innovative solutions. Full article
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20 pages, 3298 KiB  
Article
Piezoelectric Actuators in Smart Engineering Structures Using Robust Control
by Amalia Moutsopoulou, Markos Petousis, Nectarios Vidakis, Anastasios Pouliezos and Georgios E. Stavroulakis
Materials 2024, 17(10), 2357; https://doi.org/10.3390/ma17102357 (registering DOI) - 15 May 2024
Abstract
In this study, piezoelectric patches are used as actuators to dampen structural oscillations. Damping oscillations is a significant engineering challenge, and the use of piezoelectric patches in smart structures allows for a reduction in oscillations through sophisticated control methods. This analysis involved H-infinity [...] Read more.
In this study, piezoelectric patches are used as actuators to dampen structural oscillations. Damping oscillations is a significant engineering challenge, and the use of piezoelectric patches in smart structures allows for a reduction in oscillations through sophisticated control methods. This analysis involved H-infinity (H∞) robust analysis. H∞ (H-infinity) control formulation is a robust control design method used to ensure system stability and performance under disturbances. When applied to piezoelectric actuators in smart structures, H∞ control aims to design controllers that are robust to variations in system dynamics, external disturbances, and modeling uncertainties, while meeting specified performance criteria. This study outlines the piezoelectric effects and advanced control strategies. A structural model was created using finite elements, and a smart structural model was analyzed. Subsequently, dynamic loads were applied and oscillation damping was successfully achieved by employing advanced control techniques. Full article
21 pages, 2872 KiB  
Article
The Collapse Mechanism of Slope Rill Sidewall under Composite Erosion of Freeze-Thaw Cycles and Water
by Wenbin Huang, Shuai Shao, Yuhang Liu, Xiangtian Xu, Weidong Zhang and Yong Liu
Sustainability 2024, 16(10), 4144; https://doi.org/10.3390/su16104144 (registering DOI) - 15 May 2024
Abstract
The composite erosion of freeze-thaw and water flow on slope rills is characterized by periodicity and spatial superposition. When revealing the collapse mechanism of slope rill sidewalls under the composite erosion of freeze-thaw and water flow, it is necessary to fully consider the [...] Read more.
The composite erosion of freeze-thaw and water flow on slope rills is characterized by periodicity and spatial superposition. When revealing the collapse mechanism of slope rill sidewalls under the composite erosion of freeze-thaw and water flow, it is necessary to fully consider the effect of water migration and its impact on the stability of the rill sidewall. In this paper, we placed the self-developed collapse test system in an environmental chamber to carry out model tests on rill sidewall collapse on slopes under the composite erosion of freeze-thaw and water flow. We utilized three-dimensional reconstruction technology and the fixed grid coordinate method to reproduce the collapse process of the rill sidewall and precisely locate the top crack. We obtained the relationship between the water content of the specimen and mechanical indexes through the straight shear test. The main conclusions are as follows: The soil structure of the rill sidewall is significantly affected by the freeze-thaw cycle, which benefits capillary action in the soil. One freeze-thaw cycle has the most serious effect on the soil structure of the rill sidewall, and the change in the moisture field is more intense after the soil temperature drops below zero. The friction angle of the soil increases with the number of freeze-thaw cycles and tends to stabilize gradually. The effect of the freeze-thaw cycle on the rate of change of the water content of the soil at each position of the wall can be accurately described by a logarithmic function. The expression of the two-factor interaction effect on the rate of change of water content of soil at each position of the rill sidewall can be accurately fitted. We propose a calculation system for locating cracks at the top of the rill sidewall and determining the critical state of instability and collapse of the rill sidewall during the process of freeze-thaw and water flow composite erosion. The results of this research can help improve the accuracy of combined freeze-thaw and water flow erosion test equipment and the development of a prediction model for the collapse of the rill sidewall under compound erosion. This is of great significance for soil and water conservation and sustainability. Full article
(This article belongs to the Topic Environmental Geology and Engineering)
17 pages, 7420 KiB  
Article
Performance of Earth Plasters with Graphene-Based Additive
by Paola Gallo Stampino, Letizia Ceccarelli, Marco Caruso, Laura Mascheretti, Giovanni Dotelli and Sergio Sabbadini
Materials 2024, 17(10), 2356; https://doi.org/10.3390/ma17102356 (registering DOI) - 15 May 2024
Abstract
A central debate is the improvement in the mechanical and water resistance of sustainable earthen architecture without additives or stabilizers. This innovative work aims to test the effects of a graphene-based additive, optimized for the improvement in concrete properties, on the strength and [...] Read more.
A central debate is the improvement in the mechanical and water resistance of sustainable earthen architecture without additives or stabilizers. This innovative work aims to test the effects of a graphene-based additive, optimized for the improvement in concrete properties, on the strength and water resistance of raw-earth plasters without any stabilizer other than sand. Given the heterogeneous nature of raw earth, three different soils were tested by adding three increasing graphene-based additive contents (0.01, 0.05 and 0.1 wt% of the earth–sand proportion). The link between soil intrinsic properties, i.e., geotechnical and mineralogical properties, and their interaction with the additive were investigated through geotechnical characterization, as well as mineralogical characterization, by XRD and ATR-FTIR analyses. The experimental tests carried out focused on the adhesion properties of the twelve different plasters on standard hollow bricks and on their interaction with water through capillary rise tests and erosion resistance tests. Conclusion from the experimental tests suggests that the graphene-based additive in earth plasters, by increasing the cohesion of the mixture, improves their adhesion performance. Full article
(This article belongs to the Special Issue Advance in Sustainable Construction Materials)
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24 pages, 6983 KiB  
Review
Spectroscopic Techniques and Hydrogen-Sensitive Compounds: A New Horizon in Hydrogen Detection
by Bu Si, Yan Hu, Longchao Yao, Qiwen Jin, Chenghang Zheng, Yingchun Wu, Xuecheng Wu and Xiang Gao
Sensors 2024, 24(10), 3146; https://doi.org/10.3390/s24103146 (registering DOI) - 15 May 2024
Abstract
Detecting hydrogen leaks remains a pivotal challenge demanding robust solutions. Among diverse detection techniques, the fiber-optic method distinguishes itself through unique benefits, such as its distributed measurement properties. The adoption of hydrogen-sensitive materials coated on fibers has gained significant traction in research circles, [...] Read more.
Detecting hydrogen leaks remains a pivotal challenge demanding robust solutions. Among diverse detection techniques, the fiber-optic method distinguishes itself through unique benefits, such as its distributed measurement properties. The adoption of hydrogen-sensitive materials coated on fibers has gained significant traction in research circles, credited to its operational simplicity and exceptional adaptability across varied conditions. This manuscript offers an exhaustive investigation into hydrogen-sensitive materials and their incorporation into fiber-optic hydrogen sensors. The research profoundly analyzes the sensor architectures, performance indicators, and the spectrum of sensing materials. A detailed understanding of these sensors’ potentials and constraints emerges through rigorous examination, juxtaposition, and holistic discourse. Furthermore, this analysis judiciously assesses the inherent challenges tied to these systems, simultaneously highlighting potential pathways for future innovation. By spotlighting the hurdles and opportunities, this paper furnishes a view on hydrogen sensing technology, particularly related to optical fiber-based applications. Full article
(This article belongs to the Section Optical Sensors)
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