The 2023 MDPI Annual Report has
been released!
 
11 pages, 2696 KiB  
Article
Dual-Emission Origins in Bi3+-Doped M2O3 Sesquioxides (M = Sc, Y, Gd and Lu): A First-Principles Study
by Haonian Bai, Bibo Lou, Mekhrdod S. Kurboniyon, Andrzej Suchocki, Mikhail G. Brik, Jing Wang and Chonggeng Ma
Materials 2024, 17(9), 2039; https://doi.org/10.3390/ma17092039 (registering DOI) - 26 Apr 2024
Abstract
Bi3+-doped sesquioxides exhibit dual emissions, marked by distinct Stokes shift and bandwidth, meaning unraveling their underlying origins is particularly intriguing. In this study, we employ first-principles calculations to investigate the luminescence mechanisms within the M2O3:Bi3+ ( [...] Read more.
Bi3+-doped sesquioxides exhibit dual emissions, marked by distinct Stokes shift and bandwidth, meaning unraveling their underlying origins is particularly intriguing. In this study, we employ first-principles calculations to investigate the luminescence mechanisms within the M2O3:Bi3+ (M = Sc, Y, Gd, Lu) series, with the goal of addressing the posed inquiry. Our investigation commences with the analysis of the site occupancy and charge state of bismuth ions in the two cationic sites through formation energy calculations. Additionally, we examine the local coordination environments for various excited states of Bi3+ dopants, including the 3P0,1 state and two types of charge transfer states, by evaluating their equilibrium geometric structures. The utilization of the hybrid functional enables us to obtain results of electronic structures and optical properties comparable with experiments. Importantly, the calculated energies for the 6s-6p transitions of Bi3+ dopants in the M2O3 series align well with the observed dual-emission energies. This alignment challenges the conventional spectroscopic sense that emission bands with large Stokes shifts can be exclusively ascribed to charge transfer transitions. Consequently, the integration of experimental and theoretical approaches emerges as the optimal strategy for designing novel Bi3+-doped phosphors. Full article
(This article belongs to the Special Issue Glasses and Ceramics for Luminescence Applications)
14 pages, 1695 KiB  
Article
A Laser-Induced TIG Arc Narrow-Gap Welding Technique for TC4 Titanium Alloy Thick Plates Based on the Spatial Position Control of Laser, Arc and Filler Wire
by Gang Song, Zhijie Xu, Qiang Lang, Xin Liu, Hongyang Wang and Liming Liu
Metals 2024, 14(5), 510; https://doi.org/10.3390/met14050510 (registering DOI) - 26 Apr 2024
Abstract
In this paper, a novel laser-induced TIG arc narrow-gap welding technology is proposed for thick plates of TC4 titanium alloy. The feasibility of achieving high-performance welding joints is investigated by adjusting the spatial deviation position of the laser, arc, and filler wire. The [...] Read more.
In this paper, a novel laser-induced TIG arc narrow-gap welding technology is proposed for thick plates of TC4 titanium alloy. The feasibility of achieving high-performance welding joints is investigated by adjusting the spatial deviation position of the laser, arc, and filler wire. The results exhibited remarkable capabilities. By augmenting the laser-arc malposition, a stable deflection of the arc can be achieved, resulting in enhanced heat input to the sidewall adjacent to the laser side and improved fusion capability. Moreover, an inclined weld can be obtained through increased malposition between the filler wire and arc, which helps to improve interlayer fusion and suppress porosity defects. This method, involving alternating bilateral offsets between passes, successfully achieved narrow-gap welding of 24 mm-thick TC4 titanium alloy with an average tensile strength of 880.68 MPa (equivalent to 95.05% of base material strength). Therefore, this technology exhibits promising potential as an automated welding technique for achieving high-quality narrow-gap welding in titanium alloys. Full article
(This article belongs to the Special Issue Laser Processing and Surface Modification of Materials (Volume 2))
18 pages, 4645 KiB  
Article
Identifying Users’ Needs to Design and Manufacture 3D-Printed Upper Limb Sockets: A Survey-Based Study
by Alba Roda-Sales and Immaculada Llop-Harillo
Appl. Sci. 2024, 14(9), 3708; https://doi.org/10.3390/app14093708 (registering DOI) - 26 Apr 2024
Abstract
The development of prosthetic arms has increased in recent years, particularly with the growth of 3D printing technologies. However, one of the main weaknesses of 3D-printed prosthetics is the prosthetic socket, which commonly presents a generic adjustable design that may produce discomfort. In [...] Read more.
The development of prosthetic arms has increased in recent years, particularly with the growth of 3D printing technologies. However, one of the main weaknesses of 3D-printed prosthetics is the prosthetic socket, which commonly presents a generic adjustable design that may produce discomfort. In fact, the socket has always been a part that has frequently caused discomfort in traditionally manufactured prosthetics and, consequently, high rejection rates. Studies about improving the socket component in traditional and 3D-printed upper limb prostheses are scarce. Advancements in 3D printing and 3D scanning will offer a high potential to improve the design and manufacturing of 3D-printed sockets. Thus, to propose better designs and manufacturing protocols, this paper presents a questionnaire to assess the needs of upper limb prosthetics users or potential users, as well as a survey-based study with 18 respondents. The results reveal that users prioritize breathability and low cost, a stable fixing system, products without the need for shape adjustments, a light weight and comfort regarding the products they require. The results of this study provide insights into the key characteristics that sockets should accomplish according to users’ needs that are applicable to 3D-printed sockets and traditionally manufactured sockets, and they contribute to improving their design and manufacturing. Full article
(This article belongs to the Section Biomedical Engineering)
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16 pages, 2226 KiB  
Article
Research on the Mechanism of Strength Improvement in Acid–Base-Activated Low Carbon Oil Absorbent Concrete
by Dongli Wang, Zeyu Yang, Haojie Zheng, Ke Li, Huimin Pan and Tong Li
Sustainability 2024, 16(9), 3661; https://doi.org/10.3390/su16093661 (registering DOI) - 26 Apr 2024
Abstract
The aim of this study is to improve the compressive strength of oil absorbent concrete (OAC) and to encourage its use in slope protection projects. This study used fly ash and slag produced in thermal power plants to substitute cement in significant amounts [...] Read more.
The aim of this study is to improve the compressive strength of oil absorbent concrete (OAC) and to encourage its use in slope protection projects. This study used fly ash and slag produced in thermal power plants to substitute cement in significant amounts to prepare oil absorbent concrete (OAC). The water–cement ratios were set at 0.4, 0.5, and 0.6 and the sand rates were set at 30%, 35%, and 40% to investigate the effects of these factors on the oil absorption properties of the concrete, the variation of the oil absorption rate over time, and the compressive strengths at 28 days, 60 days, and 90 days. The compressive strength of oil absorbent concrete was improved by incorporating seashell powder (SC), alkali-modified seashell powder (SSC), and acid–base-modified seashell powder (CSC). The results showed that the optimal water–cement ratio for comprehensive oil absorption performance and compressive strength was 0.5, while the optimal sand ratio was 0.35. Compared with ordinary concrete, the oil absorption performance improved by 58.69%. The oil absorption rate decreased gradually over time. However, the oil absorption time could be effectively extended and the oil absorption performance could be improved by the addition of a silane modifier. The best method for seashell modification was acid–base modification. The compressive strength reached 14.32 Mpa at 28 days and 17.45 Mpa at 90 days, which was 19.62% higher than that of OAC. Scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), and X-ray diffraction (XRD) were used to analyze the microstructure of OAC. It was discovered that the inclusion of CSC caused a reaction with hydrocalumite in the concrete, resulting in the formation of alumohydrocalcite. Additionally, Ca(OH)2 in CSC facilitated the hydration reaction of mineral admixtures like fly ash and slag. At 28 days, more amorphous gels (C-S-H, C-(A)-S-H) and Aft were produced. The three components were combined to enhance the bonding between the cementitious materials and the aggregates, resulting in a denser internal structure of the OAC and improving its strength. This study promotes the use of OAC in slope protection projects. Full article
(This article belongs to the Special Issue Porous Materials for Sustainable Futures)
15 pages, 1430 KiB  
Article
Reconstruction of the Subsurface of Al-Hassa Oasis Using Gravity Geophysical Data
by Abid Khogali, Konstantinos Chavanidis, Panagiotis Kirmizakis, Alexandros Stampolidis and Pantelis Soupios
Appl. Sci. 2024, 14(9), 3707; https://doi.org/10.3390/app14093707 (registering DOI) - 26 Apr 2024
Abstract
Al-Hassa city, located in Eastern Saudi Arabia, boasts the world’s largest oasis and the most expansive naturally irrigated lands. Historically, a total of 280 natural springs facilitated significant groundwater discharge and irrigation of agricultural land. Furthermore, the water in certain springs formerly had [...] Read more.
Al-Hassa city, located in Eastern Saudi Arabia, boasts the world’s largest oasis and the most expansive naturally irrigated lands. Historically, a total of 280 natural springs facilitated significant groundwater discharge and irrigation of agricultural land. Furthermore, the water in certain springs formerly had a high temperature. The spatial variability of the water quality was evident. At the same time, Al-Hassa Oasis is situated on the northeastern side of the Ghawar field, which is the largest conventional onshore oil field in the world in terms of both reserves and daily output (approximately 3.8 mmb/d). The aforementioned traits suggest an intricate subsurface that has not yet been publicly and thoroughly characterized. Due to the presence of significant cultural noise caused by agricultural and nearby industrial activities, a robust, easy-to-use, and accurate geophysical method (gravity) was used to cover an area of 350 km2, producing the 3D subsurface model of the study area. A total of 571 gravity stations were collected, covering the whole Al-Hassa Oasis and parts of the nearby semi-urban areas. The gravity data were corrected and processed, and a 3D inversion was applied. The resulting 3D geophysical subsurface modeling unveiled an intricate subterranean configuration and revealed lateral variations in density, indicating the presence of a potential salt dome structure, as well as fracture zones that serve as conduits or obstacles to the flow of the subsurface fluids. This comprehensive modeling approach offers valuable insights into the subsurface dynamics of the broader study area, enhancing our understanding of its qualitative tectonic and hydraulic features and their impacts on the area’s natural resources, such as groundwater and hydrocarbons. Full article
(This article belongs to the Section Earth Sciences)
14 pages, 6895 KiB  
Communication
Stemness and Cell Cycle Regulators and Their Modulation by Retinoic Acid in Ewing Sarcoma
by Maria Eduarda Battistella, Natália Hogetop Freire, Bruno Toson, Matheus Dalmolin, Marcelo A. C. Fernandes, Isadora D. Tassinari, Mariane Jaeger, André T. Brunetto, Algemir L. Brunetto, Lauro Gregianin, Caroline Brunetto de Farias and Rafael Roesler
Curr. Issues Mol. Biol. 2024, 46(5), 3990-4003; https://doi.org/10.3390/cimb46050246 (registering DOI) - 26 Apr 2024
Abstract
Retinoic acid (RA) regulates stemness and differentiation in human embryonic stem cells (ESCs). Ewing sarcoma (ES) is a pediatric tumor that may arise from the abnormal development of ESCs. Here we show that RA impairs the viability of SK-ES-1 ES cells and affects [...] Read more.
Retinoic acid (RA) regulates stemness and differentiation in human embryonic stem cells (ESCs). Ewing sarcoma (ES) is a pediatric tumor that may arise from the abnormal development of ESCs. Here we show that RA impairs the viability of SK-ES-1 ES cells and affects the cell cycle. Cells treated with RA showed increased levels of p21 and its encoding gene, CDKN1A. RA reduced mRNA and protein levels of SRY-box transcription factor 2 (SOX2) as well as mRNA levels of beta III Tubulin (TUBB3), whereas the levels of CD99 increased. Exposure to RA reduced the capability of SK-ES-1 to form tumorspheres with high expression of SOX2 and Nestin. Gene expression of CD99 and CDKN1A was reduced in ES tumors compared to non-tumoral tissue, whereas transcript levels of SOX2 were significantly higher in tumors. For NES and TUBB3, differences between tumors and control tissue did not reach statistical significance. Low expression of CD99 and NES, and high expression of SOX2, were significantly associated with a poorer patient prognosis indicated by shorter overall survival (OS). Our results indicate that RA may display rather complex modulatory effects on multiple target genes associated with the maintenance of stem cell’s features versus their differentiation, cell cycle regulation, and patient prognosis in ES. Full article
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18 pages, 1090 KiB  
Article
Data-Driven Strategies for Optimizing Albania’s Utilization of Renewable Energy Sources from Urban Waste: Current Status and Future Prospects
by Sonila Vito, Ilirjana Boci, Mohammad Gheibi, Klodian Dhoska, Ilirjan Malollari, Elmaz Shehu, Reza Moezzi and Andres Annuk
World 2024, 5(2), 258-275; https://doi.org/10.3390/world5020014 (registering DOI) - 26 Apr 2024
Abstract
Albania is now implementing a range of steps as part of its journey towards European Union integration, based on agreements that have been achieved. Key to these initiatives is the extensive adoption of circular economy concepts through comprehensive waste management systems. This collaboration [...] Read more.
Albania is now implementing a range of steps as part of its journey towards European Union integration, based on agreements that have been achieved. Key to these initiatives is the extensive adoption of circular economy concepts through comprehensive waste management systems. This collaboration is based on systematically implementing measures that align with the fundamental principles of the waste management hierarchy. Albania wants to lead in waste-to-energy conversion exploration by focusing on trash minimization, reuse, recycling, and energy generation from residual waste. Although there has been notable advancement, especially in aligning laws with EU requirements, there are practical obstacles, especially in the execution of waste-to-energy projects. The challenges involve the need for effective waste segregation, higher recycling rates, and the use of advanced waste-to-energy technologies. The essay utilizes meticulously selected data on Albania’s waste generation from reputable organizations and the legal framework regulating waste management to assess the current situation and predict future possibilities, which may be advantageous for government ministries and agency platforms. Full article
(This article belongs to the Special Issue Data-Driven Strategic Approaches to Public Management)
38 pages, 1778 KiB  
Review
Neurogaming in Virtual Reality: A Review of Video Game Genres and Cognitive Impact
by Jesus GomezRomero-Borquez, Carolina Del-Valle-Soto, J. Alberto Del-Puerto-Flores, Ramon A. Briseño and José Varela-Aldás
Electronics 2024, 13(9), 1683; https://doi.org/10.3390/electronics13091683 (registering DOI) - 26 Apr 2024
Abstract
This work marks a significant advancement in the field of cognitive science and gaming technology. It offers an in-depth analysis of the effects of various video game genres on brainwave patterns and concentration levels in virtual reality (VR) settings. The study is groundbreaking [...] Read more.
This work marks a significant advancement in the field of cognitive science and gaming technology. It offers an in-depth analysis of the effects of various video game genres on brainwave patterns and concentration levels in virtual reality (VR) settings. The study is groundbreaking in its approach, employing electroencephalograms (EEGs) to explore the neural correlates of gaming, thus bridging the gap between technology, psychology, and neuroscience. This review enriches the dialogue on the potential of video games as a therapeutic tool in mental health. The study’s findings illuminate the capacity of different game genres to elicit varied brainwave responses, paving the way for tailored video game therapies. This review contributes meaningfully to the state of the art by offering empirical insights into the interaction between gaming environments and brain activity, highlighting the potential applications in therapeutic settings, cognitive training, and educational tools. The findings are especially relevant for developing VR gaming content and therapeutic games, enhancing the understanding of cognitive processes, and aiding in mental healthcare strategies. Full article
(This article belongs to the Special Issue Serious Games and Extended Reality (XR))
14 pages, 672 KiB  
Article
Research on Fe Removal, Regeneration Process, and Mechanical Properties of Mg Alloy AM50A
by Zhao Chen, Changfa Zhou, Wenbo Liu, Sanxing Chen, Cong Gao, Shaowei Jia, Xiaowen Yu, Wang Zhou, Bolin Luo and Qingshuang Zhang
Crystals 2024, 14(5), 407; https://doi.org/10.3390/cryst14050407 (registering DOI) - 26 Apr 2024
Abstract
In recent years, the widespread application of Mg alloy casting and Mg alloy products has generated a large amount of Mg alloy waste. This experiment used a single factor experimental analysis method to study the optimal process for removing Fe from Mg alloy [...] Read more.
In recent years, the widespread application of Mg alloy casting and Mg alloy products has generated a large amount of Mg alloy waste. This experiment used a single factor experimental analysis method to study the optimal process for removing Fe from Mg alloy AM50A waste, and developed an efficient Fe removal and regeneration process for Mg alloy AM50A. It was found that the optimal refining temperature for removing Fe ions was 670 °C, the optimal refining (RJ-2) agent mass ratio was 1.5%, and the optimal refining time was 40 min. Regenerated J40-1.5-AM50A Mg alloy was prepared using the best refining process, and its composition and mechanical properties were tested and analyzed. The experimental results show that the composition of the regenerated J40-1.5-AM50A Mg alloy prepared by this method is consistent with AM50A, with an Fe removal rate of 96.2%. The mechanical properties were improved compared to the original AM50A sample, with a maximum tensile strength increase of 1.611 KN and a tensile strength increase of 26.333 MPa. The elongation after fracture is 2.25 times that of the original sample. Research has shown that the RJ-2 refining agent can provide mechanical properties of magnesium alloys during the refining process. By analyzing the composition, XRD, SEM, and EDS of AM50A (Fe) and J40-1.5-AM50A, it was found that the refining process accelerates the removal of Fe in the form of Fe deposition. Full article
16 pages, 2369 KiB  
Article
Altered Functional Connectivity during Mild Transient Respiratory Impairment Induced by a Resistive Load
by Akiko Yorita, Tomotaka Kawayama, Masayuki Inoue, Takashi Kinoshita, Hanako Oda, Yoshihisa Tokunaga, Takahisa Tateishi, Yoshihisa Shoji, Naohisa Uchimura, Toshi Abe, Tomoaki Hoshino and Takayuki Taniwaki
J. Clin. Med. 2024, 13(9), 2556; https://doi.org/10.3390/jcm13092556 (registering DOI) - 26 Apr 2024
Abstract
Background: Previous neuroimaging studies have identified brain regions related to respiratory motor control and perception. However, little is known about the resting-state functional connectivity (FC) associated with respiratory impairment. We aimed to determine the FC involved in mild respiratory impairment without altering [...] Read more.
Background: Previous neuroimaging studies have identified brain regions related to respiratory motor control and perception. However, little is known about the resting-state functional connectivity (FC) associated with respiratory impairment. We aimed to determine the FC involved in mild respiratory impairment without altering transcutaneous oxygen saturation. Methods: We obtained resting-state functional magnetic resonance imaging data from 36 healthy volunteers during normal respiration and mild respiratory impairment induced by resistive load (effort breathing). ROI-to-ROI and seed-to-voxel analyses were performed using Statistical Parametric Mapping 12 and the CONN toolbox. Results: Compared to normal respiration, effort breathing activated FCs within and between the sensory perceptual area (postcentral gyrus, anterior insular cortex (AInsula), and anterior cingulate cortex) and visual cortex (the visual occipital, occipital pole (OP), and occipital fusiform gyrus). Graph theoretical analysis showed strong centrality in the visual cortex. A significant positive correlation was observed between the dyspnoea score (modified Borg scale) and FC between the left AInsula and right OP. Conclusions: These results suggested that the FCs within the respiratory sensory area via the network hub may be neural mechanisms underlying effort breathing and modified Borg scale scores. These findings may provide new insights into the visual networks that contribute to mild respiratory impairments. Full article
(This article belongs to the Section Pulmonology)
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17 pages, 5496 KiB  
Article
Nonlinear Modeling and Control Strategy Based on Type-II T-S Fuzzy in Bi-Directional DC-AC Converter
by Zhihua Chen, Ruochen Huang, Qiongbin Lin, Xinhong Yu and Zhimin Dan
Electronics 2024, 13(9), 1684; https://doi.org/10.3390/electronics13091684 (registering DOI) - 26 Apr 2024
Abstract
Bi-directional DC-AC converters are widely used in the field of electric vehicle-to-grid. However, the inductance of the grid-side interface filter is affected by the length of the grid connection and the power level, which presents nonlinear characteristics. This poses challenges for high-performance grid [...] Read more.
Bi-directional DC-AC converters are widely used in the field of electric vehicle-to-grid. However, the inductance of the grid-side interface filter is affected by the length of the grid connection and the power level, which presents nonlinear characteristics. This poses challenges for high-performance grid waveform control. In this paper, a modeling method for bi-directional DC-AC grid-connected converters based on type-II T-S fuzzy models is proposed, and the corresponding type-II T-S fuzzy control strategy is designed to address the parameter uncertainty and non-linearity issues. Simulation results show that type-II T-S fuzzy control offers superior control performance and better current waveform quality compared to type-I T-S fuzzy control under uncertainty parameter conditions. The effectiveness of the proposed strategy is further validated through a 1 kW prototype of a bi-directional DC-AC converter. Full article
19 pages, 4421 KiB  
Article
Dynamic Climate Influence on Magnesium Isotope Variation in Saline Lacustrine Dolomite: A Case Study of the Qianjiang Formation, Jianghan Basin
by Tianyu Wang, Kun Ling, Ren Wei and Lin Dong
Minerals 2024, 14(5), 459; https://doi.org/10.3390/min14050459 (registering DOI) - 26 Apr 2024
Abstract
The investigation of magnesium (Mg) isotopes in dolomite has mainly focused on marine dolomite environments, leaving a significant gap in the understanding of their dynamics within lacustrine settings, especially in saline lake basins. In this study, a total of 16 sediment core samples [...] Read more.
The investigation of magnesium (Mg) isotopes in dolomite has mainly focused on marine dolomite environments, leaving a significant gap in the understanding of their dynamics within lacustrine settings, especially in saline lake basins. In this study, a total of 16 sediment core samples from Well BX-7 in the Qianjiang Depression were sequentially selected for scanning electron microscope observation, whole-rock analysis for major and minor elements, and isotopic measurements including δ18Ocarb, δ13Ccarb, δ26Mgdol, and δ26MgSi. In addition, two intact cores were subjected to detailed analysis on the centimeter scale. Sedimentation models were established to elucidate dolomite formation under contrasting climatic conditions, specifically humid climates with a significant riverine Mg input versus relatively dry conditions with a lower Mg input. Furthermore, a quantitative model was developed to assess the magnesium flux and isotopic mass balance within lacustrine systems, simulating the magnesium isotope variations in lake water under different climatic scenarios. The dolomite sample data at a smaller scale (sampling interval ≈ 3~5 mm) demonstrate a consistent trend with the established model, providing additional confirmation of its reliability. Dolomite precipitated under humid climatic conditions exhibits a lower and relatively stable δ26Mgdol, lower δ18O, and higher CIA, indicating higher river inputs and relatively stable Mg isotope values of lake water controlled by river input. Nevertheless, dolomite formed under relatively dry climatic conditions shows a relatively high δ26Mgdol, higher δ18O, and lower CIA, suggesting reduced river inputs and weathering intensity, as well as relatively high magnesium isotope values of the lake water controlled by dolomite precipitation. This study contributes to the understanding of magnesium isotopes in lacustrine dolomite systems. Full article
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10 pages, 4313 KiB  
Article
The Influence of Thickness on Light Transmission for Pre- and Fully Crystallized Chairside CAD/CAM Lithium Disilicate Ceramics
by Franciele Floriani, Salahaldeen Abuhammoud, Silvia Rojas-Rueda, Amit Unnadkat, Nicholas G. Fischer, Chin-Chuan Fu and Carlos A. Jurado
Materials 2024, 17(9), 2045; https://doi.org/10.3390/ma17092045 (registering DOI) - 26 Apr 2024
Abstract
Aim: This in vitro study aimed to compare the light-transmission properties of two chairside CAD/CAM lithium disilicate (LD) ceramics (a novel fully crystallized and a traditional pre-crystallized) across varying thicknesses. Materials and Methods: One hundred flat specimens were obtained from precrystallized (e.max CAD, [...] Read more.
Aim: This in vitro study aimed to compare the light-transmission properties of two chairside CAD/CAM lithium disilicate (LD) ceramics (a novel fully crystallized and a traditional pre-crystallized) across varying thicknesses. Materials and Methods: One hundred flat specimens were obtained from precrystallized (e.max CAD, Ivoclar Vivadent, Schaan, Liechtenstein) and fully crystallized (LiSi GC Block; GC, Tokyo, Japan) LD at five different thicknesses (0.5, 0.75, 1.0, 1.50 and 2.0 mm). All specimens were polished with a polishing system for lithium disilicate restorations following recommendations from the manufacturer. Light transmission was evaluated with a radiometer. The statistical analysis between e.max CAD and LiSi GC Block was performed using a Mann–Whitney test for each thickness at a significance level of 0.05 (p < 0.05), followed by a Kruskal–Wallis test to compare the light transmission between the thicknesses of e.max CAD and LiSi GC Block. Results: Light transmittance was significantly affected by ceramic thickness. The 0.5 mm thick specimens exhibited the highest transmittance values compared to all other groups, while a light transmittance of 0.00 was observed in the 2.0 mm thick specimens for both e.max CAD and LiSi GC Block. In the comparison between e.max CAD and LiSi GC Block according to thickness, there was a statistically significant difference exclusively between groups with a thickness of 1.50 mm (p = 0.002). Conclusions: Light transmission for pre- and fully crystallized CAD/CAM lithium disilicate ceramics only showed a statistical difference at the thickness of 1.50 mm (p = 0.002). E.max CAD demonstrated acceptable light transmission up to a thickness of 1.5 mm. Clinical Significance: A thickness of 2 mm for chairside CAD/CAM lithium disilicate ceramics, whether pre-crystallized or fully crystallized, necessitates the use of dual-cure resin luting cement due to reduced light transmission. Full article
(This article belongs to the Special Issue Characteristics of Dental Ceramics)
19 pages, 742 KiB  
Article
A Multi-Agent RL Algorithm for Dynamic Task Offloading in D2D-MEC Network with Energy Harvesting
by Xin Mi, Huaiwen He and Hong Shen
Sensors 2024, 24(9), 2779; https://doi.org/10.3390/s24092779 (registering DOI) - 26 Apr 2024
Abstract
Delay-sensitive task offloading in a device-to-device assisted mobile edge computing (D2D-MEC) system with energy harvesting devices is a critical challenge due to the dynamic load level at edge nodes and the variability in harvested energy. In this paper, we propose a joint dynamic [...] Read more.
Delay-sensitive task offloading in a device-to-device assisted mobile edge computing (D2D-MEC) system with energy harvesting devices is a critical challenge due to the dynamic load level at edge nodes and the variability in harvested energy. In this paper, we propose a joint dynamic task offloading and CPU frequency control scheme for delay-sensitive tasks in a D2D-MEC system, taking into account the intricacies of multi-slot tasks, characterized by diverse processing speeds and data transmission rates. Our methodology involves meticulous modeling of task arrival and service processes using queuing systems, coupled with the strategic utilization of D2D communication to alleviate edge server load and prevent network congestion effectively. Central to our solution is the formulation of average task delay optimization as a challenging nonlinear integer programming problem, requiring intelligent decision making regarding task offloading for each generated task at active mobile devices and CPU frequency adjustments at discrete time slots. To navigate the intricate landscape of the extensive discrete action space, we design an efficient multi-agent DRL learning algorithm named MAOC, which is based on MAPPO, to minimize the average task delay by dynamically determining task-offloading decisions and CPU frequencies. MAOC operates within a centralized training with decentralized execution (CTDE) framework, empowering individual mobile devices to make decisions autonomously based on their unique system states. Experimental results demonstrate its swift convergence and operational efficiency, and it outperforms other baseline algorithms. Full article
(This article belongs to the Section Communications)
10 pages, 289 KiB  
Data Descriptor
Training Datasets for Epilepsy Analysis: Preprocessing and Feature Extraction from Electroencephalography Time Series
by Christian Riccio, Angelo Martone, Gaetano Zazzaro and Luigi Pavone
Data 2024, 9(5), 61; https://doi.org/10.3390/data9050061 (registering DOI) - 26 Apr 2024
Abstract
We describe 20 datasets derived through signal filtering and feature extraction steps applied to the raw time series EEG data of 20 epileptic patients, as well as the methods we used to derive them. Background: Epilepsy is a complex neurological disorder which has [...] Read more.
We describe 20 datasets derived through signal filtering and feature extraction steps applied to the raw time series EEG data of 20 epileptic patients, as well as the methods we used to derive them. Background: Epilepsy is a complex neurological disorder which has seizures as its hallmark. Electroencephalography plays a crucial role in epilepsy assessment, offering insights into the brain’s electrical activity and advancing our understanding of seizures. The availability of tagged training sets covering all seizure phases—inter-ictal, pre-ictal, ictal, and post-ictal—is crucial for data-driven epilepsy analyses. Methods: Using the sliding window technique with a two-second window length and a one-second time slip, we extract multiple features from the preprocessed EEG time series of 20 patients from the Freiburg Seizure Prediction Database. In addition, we assign a class label to each instance to specify its corresponding seizure phase. All these operations are made through a software application we developed, which is named Training Builder. Results: The 20 tagged training datasets each contain 1080 univariate and bivariate features, and are openly and publicly available. Conclusions: The datasets support the training of data-driven models for seizure detection, prediction, and clustering, based on features engineering. Full article
14 pages, 510 KiB  
Communication
Influence of Human Bone Marrow Mesenchymal Stem Cells Secretome from Acute Myeloid Leukemia Patients on the Proliferation and Death of K562 and K562-Lucena Leukemia Cell Lineages
by Fábio Alessandro de Freitas, Débora Levy, Cadiele Oliana Reichert, Juliana Sampaio-Silva, Pedro Nogueira Giglio, Luís Alberto de Pádua Covas Lage, Marco Kawamura Demange, Juliana Pereira and Sérgio Paulo Bydlowski
Int. J. Mol. Sci. 2024, 25(9), 4748; https://doi.org/10.3390/ijms25094748 (registering DOI) - 26 Apr 2024
Abstract
Leukemias are among the most prevalent types of cancer worldwide. Bone marrow mesenchymal stem cells (MSCs) participate in the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases such as leukemias, to a yet unknown [...] Read more.
Leukemias are among the most prevalent types of cancer worldwide. Bone marrow mesenchymal stem cells (MSCs) participate in the development of a suitable niche for hematopoietic stem cells, and are involved in the development of diseases such as leukemias, to a yet unknown extent. Here we described the effect of secretome of bone marrow MSCs obtained from healthy donors and from patients with acute myeloid leukemia (AML) on leukemic cell lineages, sensitive (K562) or resistant (K562-Lucena) to chemotherapy drugs. Cell proliferation, viability and death were evaluated, together with cell cycle, cytokine production and gene expression of ABC transporters and cyclins. The secretome of healthy MSCs decreased proliferation and viability of both K562 and K562‑Lucena cells; moreover, an increase in apoptosis and necrosis rates was observed, together with the activation of caspase 3/7, cell cycle arrest in G0/G1 phase and changes in expression of several ABC proteins and cyclins D1 and D2. These effects were not observed using the secretome of MSCs derived from AML patients. In conclusion, the secretome of healthy MSCs have the capacity to inhibit the development of leukemia cells, at least in the studied conditions. However, MSCs from AML patients seem to have lost this capacity, and could therefore contribute to the development of leukemia. Full article
(This article belongs to the Special Issue Mesenchymal Stem Cells and Cancer)
12 pages, 2651 KiB  
Article
The Influence of Maturity, Storage, and Embryo Size on Coconut Callus Induction Success
by Zhihua Mu, Shuya Yang, Hang Xu, Zhuang Yang, Mirza Mobashwerul Haque, Binh-Minh Tran, Jiepeng Chen, Xingwei Wang, Hui Peng and Jie Luo
Forests 2024, 15(5), 764; https://doi.org/10.3390/f15050764 (registering DOI) - 26 Apr 2024
Abstract
Coconut palms (Cocos nucifera L.) are globally significant palms with both economic and cultural value. Despite the increasing demand for coconut products, production is decreasing globally due to palm senility, pests, and diseases. It has been estimated that over half of the [...] Read more.
Coconut palms (Cocos nucifera L.) are globally significant palms with both economic and cultural value. Despite the increasing demand for coconut products, production is decreasing globally due to palm senility, pests, and diseases. It has been estimated that over half of the world’s coconut palms need to be replaced immediately. The coconut industry has acknowledged that conventional propagation methods are unlikely to yield sufficient high-quality planting material. Therefore, coconut tissue culture is considered a potential solution to this problem. By using coconut tissue culture, a large number of plantlets can be obtained in a short period of time. In this study, the quality of explants and the development stage (visible shoot/non-visible shoot) of coconut used for micropropagation were examined. To our knowledge, little research has been undertaken on this aspect of coconut micropropagation. Our results indicated that tender coconut fruit exhibited an advantage over mature fruits. In addition, coconut plumule explants subjected to an extended storage of 15 days demonstrated enhanced development compared to those without storage. Notably, smaller embryos utilized as explants displayed superior callus formation compared to their larger counterparts. Finally, embryos possessing shoots exhibited improved callus initiation, albeit accompanied by a more pronounced browning effect. Further investigations are required to obtain more knowledge about the most suitable conditions for plumule explants that lead to optimal callus initiation. Full article
(This article belongs to the Special Issue Somatic Embryogenesis and Other Vegetative Propagation Technologies)
17 pages, 1476 KiB  
Article
A Three-Dimensional Velocity Field Related to a Generalized Third-Grade Fluid Model
by Fernando Carapau, Paulo Correia and Gracino Rodrigues
Mathematics 2024, 12(9), 1326; https://doi.org/10.3390/math12091326 (registering DOI) - 26 Apr 2024
Abstract
In this work, we propose a new three-dimensional constitutive equation related to a third-grade fluid. This proposal is based on experimental work for which the viscosity term and the terms related to viscoelasticity may depend on the shear rate, in accordance with a [...] Read more.
In this work, we propose a new three-dimensional constitutive equation related to a third-grade fluid. This proposal is based on experimental work for which the viscosity term and the terms related to viscoelasticity may depend on the shear rate, in accordance with a power-law type model. The numerical implementation of this fluid model is rather demanding in terms of computational calculation and, in this sense, we use the Cosserat theory related to fluid dynamics, which makes the transition from the three-dimensional fluid model to a one-dimensional fluid model for a specific geometry under study which, in this case, is a straight tube with constant circular cross-section. Based on this approximation theory, the one-dimensional fluid model is solved by assuming an ordinary differential equation involving: an unsteady mean pressure gradient; an unsteady volume flow rate; the Womersley number; and the viscosity and viscoelasticity parameters. Consequently, for specific data, and using the Runge–Kutta method, we can obtain the solution for the unsteady volume flow rate and we can present simulations to the three-dimensional velocity field. Full article
(This article belongs to the Section Mathematical Physics)
15 pages, 7739 KiB  
Article
Latent Heat Flux Trend and Its Seasonal Dependence over the East China Sea Kuroshio Region
by Chengji Chen and Qiang Wang
J. Mar. Sci. Eng. 2024, 12(5), 722; https://doi.org/10.3390/jmse12050722 (registering DOI) - 26 Apr 2024
Abstract
Investigating latent heat flux (LHF) variations in the western boundary current region is crucial for understanding air–sea interactions. In this study, we examine the LHF trend in the East China Sea Kuroshio Region (ECSKR) from 1959 to 2021 using atmospheric and oceanic reanalysis [...] Read more.
Investigating latent heat flux (LHF) variations in the western boundary current region is crucial for understanding air–sea interactions. In this study, we examine the LHF trend in the East China Sea Kuroshio Region (ECSKR) from 1959 to 2021 using atmospheric and oceanic reanalysis datasets and find that the LHF has a significant strengthening trend. This strengthening can be attributed to sea surface warming resulting from the advection of sea surface temperatures. More importantly, the LHF trend has an apparent seasonal dependence: the most substantial increasing trend in LHF is observed in spring, while the trends are weak in other seasons. Further analysis illustrates that the anomaly of air–sea humidity difference plays a pivotal role in controlling the seasonal variations in LHF trends. Specifically, as a result of the different responses of the East Asian Trough to global warming across different seasons, during spring, the East Asian Trough significantly deepens, resulting in northerly winds that facilitate the intrusion of dry and cold air into the ECSKR region. This intensifies the humidity difference between the sea and air, promoting the release of oceanic latent heat. These findings can contribute to a better understanding of the surface heat budget balance within western boundary currents. Full article
(This article belongs to the Special Issue Air-Sea Interaction and Marine Dynamics)
13 pages, 1651 KiB  
Article
Validation of Bos taurus SNPs for Milk Productivity of Sahiwal Breed (Bos indicus), Pakistan
by Asma Younis, Imtiaz Hussain, Syeda Nadia Ahmad, Amin Shah, Iram Inayat, Muhammad Ali Kanwal, Sadia Suleman, Muhammad Atif Kamran, Saima Matloob and Khawaja Raees Ahmad
Animals 2024, 14(9), 1306; https://doi.org/10.3390/ani14091306 (registering DOI) - 26 Apr 2024
Abstract
The aim of the present study was the validation of the already reported Bos taurus SNPs in the Sahiwal breed. A total of nine SNPs of the casein gene were studied. Out of nine, seven Bos taurus SNPs of casein protein genes were [...] Read more.
The aim of the present study was the validation of the already reported Bos taurus SNPs in the Sahiwal breed. A total of nine SNPs of the casein gene were studied. Out of nine, seven Bos taurus SNPs of casein protein genes were found to be significantly associated with milk productivity traits. The genomic DNA was extracted from the mammary alveolar endothelial cells of a flock of 80 purebred Sahiwal lactating dams available at Khizrabad Farm near Sargodha. New allele-specific primers were designed from the NCBI annotated sequence database of Bos taurus to obtain 100 nt-long PCR products. Each dam was tested separately for all the SNPs investigated. Animals with genotype GG for the SNPs rs43703010, rs10500451, and 110323127, respectively, exhibited high milk yield. Similarly, animals with genotype AA for the SNPs rs11079521, rs43703016, and rs43703017 showed high milk yield consistently. For the SNP rs43703015, animals with genotype CC showed high milk productivity. These above-mentioned SNPs have previously been reported to significantly up-regulate casein protein contents in Bos taurus. Our results indicated SNPs that significantly affect the milk protein contents may also significantly increase per capita milk yield. These finding suggest that the above-mentioned reported SNPs can also be used as genetic markers of milk productivity in Sahiwal cattle. Full article
(This article belongs to the Section Cattle)
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13 pages, 1002 KiB  
Article
Biosynthetic Pathways of Tryptophan Metabolites in Saccharomyces cerevisiae Strain: Insights and Implications
by Hsin-Chieh Kung, Ngoc-Han Bui, Bo-Wun Huang, Nicholas Kiprotich Cheruiyot and Guo-Ping Chang-Chien
Int. J. Mol. Sci. 2024, 25(9), 4747; https://doi.org/10.3390/ijms25094747 (registering DOI) - 26 Apr 2024
Abstract
Tryptophan metabolites, such as 5-hydroxytryptophan (5-HTP), serotonin, and melatonin, hold significant promise as supplements for managing various mood-related disorders, including depression and insomnia. However, their chemical production via chemical synthesis and phytochemical extraction presents drawbacks, such as the generation of toxic byproducts and [...] Read more.
Tryptophan metabolites, such as 5-hydroxytryptophan (5-HTP), serotonin, and melatonin, hold significant promise as supplements for managing various mood-related disorders, including depression and insomnia. However, their chemical production via chemical synthesis and phytochemical extraction presents drawbacks, such as the generation of toxic byproducts and low yields. In this study, we explore an alternative approach utilizing S. cerevisiae STG S101 for biosynthesis. Through a series of eleven experiments employing different combinations of tryptophan supplementation, Tween 20, and HEPES buffer, we investigated the production of these indolamines. The tryptophan metabolites were analyzed using liquid chromatography with tandem mass spectrometry (LC-MS/MS). Notably, setups replacing peptone in the YPD media with tryptophan (Run 3) and incorporating tryptophan along with 25 mM HEPES buffer (Run 4) demonstrated successful biosynthesis of 5-HTP and serotonin. The highest 5-HTP and serotonin concentrations were 58.9 ± 16.0 mg L−1 and 0.0650 ± 0.00211 mg L−1, respectively. Melatonin concentrations were undetected in all the setups. These findings underscore the potential of using probiotic yeast strains as a safer and conceivably more cost-effective alternative for indolamine synthesis. The utilization of probiotic strains presents a promising avenue, potentially offering scalability, sustainability, reduced environmental impact, and feasibility for large-scale production. Full article
(This article belongs to the Special Issue Tryptophan in Nutrition and Health 3.0)
14 pages, 1008 KiB  
Article
Transfer Learning for Automatic Sleep Staging Using a Pre-Gelled Electrode Grid
by Fabian A. Radke, Carlos F. da Silva Souto, Wiebke Pätzold and Karen Insa Wolf
Diagnostics 2024, 14(9), 909; https://doi.org/10.3390/diagnostics14090909 (registering DOI) - 26 Apr 2024
Abstract
Novel sensor solutions for sleep monitoring at home could alleviate bottlenecks in sleep medical care as well as enable selective or continuous observation over long periods of time and contribute to new insights in sleep medicine and beyond. Since especially in the latter [...] Read more.
Novel sensor solutions for sleep monitoring at home could alleviate bottlenecks in sleep medical care as well as enable selective or continuous observation over long periods of time and contribute to new insights in sleep medicine and beyond. Since especially in the latter case the sensor data differ strongly in signal, number and extent of sensors from the classical polysomnography (PSG) sensor technology, an automatic evaluation is essential for the application. However, the training of an automatic algorithm is complicated by the fact that the development phase of the new sensor technology, extensive comparative measurements with standardized reference systems, is often not possible and therefore only small datasets are available. In order to circumvent high system-specific training data requirements, we employ pre-training on large datasets with finetuning on small datasets of new sensor technology to enable automatic sleep phase detection for small test series. By pre-training on publicly available PSG datasets and finetuning on 12 nights recorded with new sensor technology based on a pre-gelled electrode grid to capture electroencephalography (EEG), electrooculography (EOG) and electromyography (EMG), an F1 score across all sleep phases of 0.81 is achieved (wake 0.84, N1 0.62, N2 0.81, N3 0.87, REM 0.88), using only EEG and EOG. The analysis additionally considers the spatial distribution of the channels and an approach to approximate classical electrode positions based on specific linear combinations of the new sensor grid channels. Full article
(This article belongs to the Special Issue Deep Learning Applications in Healthcare Wearable Devices)
26 pages, 27233 KiB  
Article
Quantitative Assessment of the Impact of the Three-North Shelter Forest Program on Vegetation Net Primary Productivity over the Past Two Decades and Its Environmental Benefits in China
by Junling Zhang and Yifei Zhang
Sustainability 2024, 16(9), 3656; https://doi.org/10.3390/su16093656 (registering DOI) - 26 Apr 2024
Abstract
Vegetation net primary productivity (NPP) is a crucial indicator for assessing the carbon balance in terrestrial ecosystems. Qualitative and comparative research on the NPP influenced by human activities, climate change, and their interactions remains insufficient. The Three-North Shelter Forest Program (TNSFP), initiated in [...] Read more.
Vegetation net primary productivity (NPP) is a crucial indicator for assessing the carbon balance in terrestrial ecosystems. Qualitative and comparative research on the NPP influenced by human activities, climate change, and their interactions remains insufficient. The Three-North Shelter Forest Program (TNSFP), initiated in 1978, provides a valuable reference for such investigations. This study employs an improved residual trend method to analyze the spatiotemporal patterns, trends, and driving factors of vegetation NPP during the second phase of the Three-North Shelter Forest Program (2001–2020), as well as TNSFP’s contribution to vegetation NPP. The results indicate that (1) from 2001 to 2020, overall vegetation NPP exhibited a significant fluctuating upward trend at a rate of 3.69 g C/m−2 annually; and (2) precipitation, accounting for 1.527 g C/m−2, had a more significant impact on vegetation net productivity compared to temperature (0.002 g C/m−2). Climate factors (76%) significantly influenced vegetation NPP in the Three-North Shelter Forest region more than human activities (24%). In the last decade (2011–2020), the climate contribution rate decreased to 67%, while the human activity contribution rate increased by seven percentage points compared to the previous decade (2001–2010); (3) during 2001–2020, TNSFP contributed 10.9% to the total human activity contribution to vegetation net primary productivity, approximately 2.6% of the overall contribution; (4) After the second phase of TNSFP was enacted, PM2.5 levels decreased by an average of −0.57 μg/m−3/a−1. Concurrently, soil conservation improved from 6.57 t/km2 in 2001 to 14.37 t/km2 in 2020. Full article
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