The 2023 MDPI Annual Report has
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14 pages, 1673 KiB  
Article
Effect of Menthol Treatment on the Sprouting and Quality of Potato Tuber
by Ye Xu, Yang Qin, Qianqian Hou, Defu Niu and Qingmin Chen
Horticulturae 2024, 10(5), 528; https://doi.org/10.3390/horticulturae10050528 (registering DOI) - 20 May 2024
Abstract
This study used Dutch potatoes at the end of dormancy as a material to explore the impact of menthol (0.2 and 0.5 g/kg based on potato mass) treatment on sprouting inhibition and potato quality. The findings revealed that a menthol concentration of 0.5 [...] Read more.
This study used Dutch potatoes at the end of dormancy as a material to explore the impact of menthol (0.2 and 0.5 g/kg based on potato mass) treatment on sprouting inhibition and potato quality. The findings revealed that a menthol concentration of 0.5 g/kg effectively inhibited potato tuber sprouting and significantly reduced glucoside alkaloid production. After a storage period of 15 days, the sprouting percentage and glucoside alkaloid content of potatoes treated with 0.5 g/kg menthol were observed to be significantly lower at 4.17% and 68.63 mg/kg, respectively, compared to the control group which exhibited values of 100% and 282.01 mg/kg, respectively (p < 0.05). Throughout the storage period, 0.5 g/kg of menthol promoted respiration, reduced malondialdehyde production in potatoes, inhibited polyphenol oxidase activity, and slowed down tissue browning. Additionally, it mitigated the decline in starch and soluble protein content, inhibiting the accumulation of reducing sugars. Full article
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18 pages, 8347 KiB  
Article
New Year Fireworks Influence on Air Quality in Case of Stagnant Foggy Conditions
by Audrė Kalinauskaitė, Lina Davulienė, Julija Pauraite, Agnė Minderytė and Steigvilė Byčenkienė
Urban Sci. 2024, 8(2), 54; https://doi.org/10.3390/urbansci8020054 (registering DOI) - 20 May 2024
Abstract
Urban science plays a pivotal role in understanding the complex interactions between fireworks, air quality, and urban environments. Dense firework smoke worsens air quality and poses a health hazard to the public. In this study, we show a situation where extremely foggy meteorological [...] Read more.
Urban science plays a pivotal role in understanding the complex interactions between fireworks, air quality, and urban environments. Dense firework smoke worsens air quality and poses a health hazard to the public. In this study, we show a situation where extremely foggy meteorological conditions coincided with intense anthropogenic emissions, including fireworks, in an urban area. For the first time, the chemical composition and sources of non-refractory submicron aerosol (NR-PM1) in outdoor and indoor air were characterized in Vilnius (Lithuania) using an aerosol chemical speciation monitor (ACSM) and Positive Matrix Factorization for the period before the fireworks, on New Year’s Eve, and after the fireworks in 2020/2021; thus, typical changes were assessed. Due to stagnant weather conditions and increased traffic, the highest concentrations of black carbon (BC) (13.8 μg/m3) were observed before the fireworks display. The contribution of organic (Org) fraction to the total NR-PM1 mass concentration, in the comparison of the values of a typical night and New Year’s Eve (from 9 p.m. to 6 a.m.), increased from 43% to 70% and from 47% to 60% in outdoor and indoor air, respectively. Biomass-burning organic aerosol (BBOA, 48% (44%)) and hydrocarbon-like organic aerosol (HOA, 35% (21%)) dominated the organic fraction indoors and outdoors, respectively. HOA was likely linked to increased traffic during the event, while BBOA may have been related to domestic heating and fireworks. Full article
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30 pages, 15359 KiB  
Review
Advancement in Cancer Vasculogenesis Modeling through 3D Bioprinting Technology
by Arvind Kumar Shukla, Sik Yoon, Sae-Ock Oh, Dongjun Lee, Minjun Ahn and Byoung Soo Kim
Biomimetics 2024, 9(5), 306; https://doi.org/10.3390/biomimetics9050306 (registering DOI) - 20 May 2024
Abstract
Cancer vasculogenesis is a pivotal focus of cancer research and treatment given its critical role in tumor development, metastasis, and the formation of vasculogenic microenvironments. Traditional approaches to investigating cancer vasculogenesis face significant challenges in accurately modeling intricate microenvironments. Recent advancements in three-dimensional [...] Read more.
Cancer vasculogenesis is a pivotal focus of cancer research and treatment given its critical role in tumor development, metastasis, and the formation of vasculogenic microenvironments. Traditional approaches to investigating cancer vasculogenesis face significant challenges in accurately modeling intricate microenvironments. Recent advancements in three-dimensional (3D) bioprinting technology present promising solutions to these challenges. This review provides an overview of cancer vasculogenesis and underscores the importance of precise modeling. It juxtaposes traditional techniques with 3D bioprinting technologies, elucidating the advantages of the latter in developing cancer vasculogenesis models. Furthermore, it explores applications in pathological investigations, preclinical medication screening for personalized treatment and cancer diagnostics, and envisages future prospects for 3D bioprinted cancer vasculogenesis models. Despite notable advancements, current 3D bioprinting techniques for cancer vasculogenesis modeling have several limitations. Nonetheless, by overcoming these challenges and with technological advances, 3D bioprinting exhibits immense potential for revolutionizing the understanding of cancer vasculogenesis and augmenting treatment modalities. Full article
(This article belongs to the Special Issue Biomimetic 3D/4D Printing)
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12 pages, 437 KiB  
Study Protocol
MUltiparametric Score for Ventilation Discontinuation in Intensive Care Patients: A Protocol for an Observational Study
by Iacopo Cappellini, Andrea Cardoni, Lorenzo Campagnola and Guglielmo Consales
Methods Protoc. 2024, 7(3), 45; https://doi.org/10.3390/mps7030045 (registering DOI) - 20 May 2024
Abstract
Background: Mechanical ventilation significantly improves patient survival but is associated with complications, increasing healthcare costs and morbidity. Identifying optimal weaning times is paramount to minimize these risks, yet current methods rely heavily on clinical judgment, lacking specificity. Methods: This study introduces a novel [...] Read more.
Background: Mechanical ventilation significantly improves patient survival but is associated with complications, increasing healthcare costs and morbidity. Identifying optimal weaning times is paramount to minimize these risks, yet current methods rely heavily on clinical judgment, lacking specificity. Methods: This study introduces a novel multiparametric predictive score, the MUSVIP (MUltiparametric Score for Ventilation discontinuation in Intensive care Patients), aimed at accurately predicting successful extubation. Conducted at Santo Stefano Hospital’s ICU, this single-center, observational, prospective cohort study will span over 12 months, enrolling adult patients undergoing invasive mechanical ventilation. The MUSVIP integrates variables measured before and during a spontaneous breathing trial (SBT) to formulate a predictive score. Results: Preliminary analyses suggest an Area Under the Curve (AUC) of 0.815 for the MUSVIP, indicating high predictive capacity. By systematically applying this score, we anticipate identifying patients likely to succeed in weaning earlier, potentially reducing ICU length of stay and associated healthcare costs. Conclusion: This study’s findings could significantly influence clinical practices, offering a robust, easy-to-use tool for optimizing weaning processes in ICUs. Full article
(This article belongs to the Section Biomedical Sciences and Physiology)
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17 pages, 801 KiB  
Review
Recent Advances in Understanding and Controlling Fusarium Diseases of Alliums
by Suman Sharma, Subhankar Mandal and Christopher S. Cramer
Horticulturae 2024, 10(5), 527; https://doi.org/10.3390/horticulturae10050527 (registering DOI) - 20 May 2024
Abstract
Allium species are known for their culinary, medicinal, and ornamental purposes. Fusarium basal rot is one of the most damaging soilborne fungal diseases of Allium species and poses a significant threat to yield, quality, and storage life worldwide. Various species of Fusarium have [...] Read more.
Allium species are known for their culinary, medicinal, and ornamental purposes. Fusarium basal rot is one of the most damaging soilborne fungal diseases of Allium species and poses a significant threat to yield, quality, and storage life worldwide. Various species of Fusarium have been identified as causal agents for Fusarium basal rot, depending on the Allium species involved. Diverse disease management practices have been implemented to mitigate the impact of Fusarium basal rot. This review article provides a comprehensive overview of the recent progress in detecting different species of Fusarium involved in Fusarium basal rot and strategies to control them in affected Allium species involving chemical, biological, and cultural methods. It covers the latest advancements in host plant resistance research from traditional breeding to modern molecular techniques and studying secondary metabolites involved in defense mechanisms against Fusarium basal rot. Full article
(This article belongs to the Section Genetics, Genomics, Breeding, and Biotechnology (G2B2))
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21 pages, 1757 KiB  
Review
Cortical and Trabecular Bone Modeling and Implications for Bone Functional Adaptation in the Mammalian Tibia
by Meir M. Barak
Bioengineering 2024, 11(5), 514; https://doi.org/10.3390/bioengineering11050514 (registering DOI) - 20 May 2024
Abstract
Bone modeling involves the addition of bone material through osteoblast-mediated deposition or the removal of bone material via osteoclast-mediated resorption in response to perceived changes in loads by osteocytes. This process is characterized by the independent occurrence of deposition and resorption, which can [...] Read more.
Bone modeling involves the addition of bone material through osteoblast-mediated deposition or the removal of bone material via osteoclast-mediated resorption in response to perceived changes in loads by osteocytes. This process is characterized by the independent occurrence of deposition and resorption, which can take place simultaneously at different locations within the bone due to variations in stress levels across its different regions. The principle of bone functional adaptation states that cortical and trabecular bone tissues will respond to mechanical stimuli by adjusting (i.e., bone modeling) their morphology and architecture to mechanically improve their mechanical function in line with the habitual in vivo loading direction. This principle is relevant to various research areas, such as the development of improved orthopedic implants, preventative medicine for osteopenic elderly patients, and the investigation of locomotion behavior in extinct species. In the present review, the mammalian tibia is used as an example to explore cortical and trabecular bone modeling and to examine its implications for the functional adaptation of bones. Following a short introduction and an exposition on characteristics of mechanical stimuli that influence bone modeling, a detailed critical appraisal of the literature on cortical and trabecular bone modeling and bone functional adaptation is given. By synthesizing key findings from studies involving small mammals (rodents), large mammals, and humans, it is shown that examining both cortical and trabecular bone structures is essential for understanding bone functional adaptation. A combined approach can provide a more comprehensive understanding of this significant physiological phenomenon, as each structure contributes uniquely to the phenomenon. Full article
(This article belongs to the Section Biomedical Engineering and Biomaterials)
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19 pages, 4401 KiB  
Article
Modulation of Canine Adipose-Derived Mesenchymal Stem/Medicinal Signalling Cells with Ascorbic Acid: Effect on Proliferation and Chondrogenic Differentiation on Standard Plastic and Silk Fibroin Surfaces
by Metka Voga
Bioengineering 2024, 11(5), 513; https://doi.org/10.3390/bioengineering11050513 (registering DOI) - 20 May 2024
Abstract
Ascorbic acid (AA) plays a crucial role in both the proliferation and chondrogenic differentiation potential of mesenchymal stem/medicinal signalling cells (MSCs); these are both key aspects of their general therapeutic use and their increasing use in veterinary medicine. Current immunomodulatory therapies require efficient [...] Read more.
Ascorbic acid (AA) plays a crucial role in both the proliferation and chondrogenic differentiation potential of mesenchymal stem/medicinal signalling cells (MSCs); these are both key aspects of their general therapeutic use and their increasing use in veterinary medicine. Current immunomodulatory therapies require efficient expansion of MSCs in the laboratory, while emerging tissue regeneration strategies, such as cartilage or bone repair, aim to use differentiated MSCs and modulate the expression of chondrogenic and hypertrophic markers. Our aim was to investigate whether the addition of AA to the growth medium enhances the proliferation of canine adipose-derived MSCs (cAMSCs) grown on standard plastic surfaces and whether it affects chondrogenic differentiation potential on silk fibroin (SF) films. We assessed cell viability with trypan blue and proliferation potential by calculating population doubling. Chondrogenic induction on SF films was assessed by Alcian blue staining and gene expression analysis of chondrogenic and hypertrophic genes. The results showed that growth medium with AA significantly enhanced the proliferation of cAMSCs without affecting cell viability and modulated the expression of chondrogenic and hypertrophic genes of cAMSCs grown on SF films. Our results suggest that AA may be used in growth medium for expansion of cAMSCs and, at the same time, provide the basis for future studies to investigate the role of AA and SF in chondrogenic differentiation of MSCs. Full article
(This article belongs to the Special Issue Tissue Engineering and Regenerative Medicine in Bioengineering)
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9 pages, 15786 KiB  
Article
Quantitative Analysis of Stress–Stretch Curves in Canine Lumbar Vertebrae Using Modified Logistic Functions
by Ernest Kostenko, Rimantas Stonkus, Jakov Šengaut, Nikolaj Višniakov and Algirdas Maknickas
Bioengineering 2024, 11(5), 516; https://doi.org/10.3390/bioengineering11050516 (registering DOI) - 20 May 2024
Abstract
Background: The mechanical characteristics of bone are crucial for comprehending its functionality and response to different load conditions, which are essential for advancing medical treatments, implants, and prosthetics. By employing mathematical modeling to analyze the mechanical properties of bone, we can assess stress [...] Read more.
Background: The mechanical characteristics of bone are crucial for comprehending its functionality and response to different load conditions, which are essential for advancing medical treatments, implants, and prosthetics. By employing mathematical modeling to analyze the mechanical properties of bone, we can assess stress and deformation under both normal and abnormal conditions. This analysis offers valuable perspectives on potential fracture risks, the effects of diseases, and the effectiveness of various treatments. Therefore, researchers are attempting to find an adequate mathematical description of the mechanical properties of bone. Methods: Experimental stress–stretch external loading curves were obtained through investigations of canine vertebrae. The obtained experimental curves were fitted using the SciPy Python library with a slightly modified logistic function (logistic function plus additional const). Results: The resulting coefficient of determination R2 (R squared) for most curves was near 0.999, indicating that an appropriate fitting function was selected for the description of the experimental stress–stretch curves. Conclusions: The stress–stretch behavior of canine vertebrae can be described using a logistic function modified by adding additional parameters for the most accurate fitting results. Full article
(This article belongs to the Section Biomechanics and Sports Medicine)
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14 pages, 1782 KiB  
Systematic Review
Bone Bruises and Concomitant Meniscus and Cartilage Damage in Anterior Cruciate Ligament Injuries: A Systematic Review and Meta-Analysis
by Sueen Sohn, Saad Mohammed AlShammari, Jeong Han Lee and Man Soo Kim
Bioengineering 2024, 11(5), 515; https://doi.org/10.3390/bioengineering11050515 (registering DOI) - 20 May 2024
Abstract
(1) Background: Bone bruises in acute anterior cruciate ligament (ACL) injuries are closely linked to the occurrence of simultaneous meniscal and cartilage damage. Despite the frequent occurrence of associated injuries including bone bruises, meniscus, and cartilage damage in patients with ACL injuries, a [...] Read more.
(1) Background: Bone bruises in acute anterior cruciate ligament (ACL) injuries are closely linked to the occurrence of simultaneous meniscal and cartilage damage. Despite the frequent occurrence of associated injuries including bone bruises, meniscus, and cartilage damage in patients with ACL injuries, a systematic review of the relationships between the presence of bone bruises and the extent of meniscus and cartilage injuries has yet to be conducted. (2) Methods: Multiple comprehensive databases, including MEDLINE, EMBASE, and the Cochrane Library, were searched for studies that evaluated the relationship between bone bruises and meniscus or cartilage injuries following ACL injuries. Study selection, data extraction, and meta-analysis were performed. The Methodological Index for Non-Randomized Studies (MINORS) was used for quality assessments, and Review Manager 5.3 was used for data analysis. (3) Results: Data were extracted from 22 studies encompassing a total of 2891 patients with ACL injuries. Among the included studies, six studies investigated the relationships between bone bruises and medial meniscus (MM) or lateral meniscus (LM) injuries, while three studies investigated the relationships between bone bruises and cartilage injuries. There were no significant correlations between the presence of bone bruises and MM injuries (relative risk (RR) = 1.32; p = 0.61). A quantitative analysis indicated that individuals with bone bruises had a 2.71-fold higher likelihood of sustaining LM injuries than those without bone bruises (RR = 2.71; p = 0.0003). The analysis confirmed a significant relationship between bone bruises and cartilage injuries (RR = 6.18; p = 0.003). (4) Conclusions: Bone bruises occur most frequently in the lateral compartment. Bone bruises resulting from ACL injuries are related to accompanying LM injuries and cartilage injuries. Knowing these associations and the frequency of injuries may allow orthopedic surgeons to promptly address ACL-related meniscus and cartilage injuries on MRI results and in future clinical practice. Full article
(This article belongs to the Section Biomechanics and Sports Medicine)
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15 pages, 5837 KiB  
Article
Synergistic Antibacterial Properties of Silver Nanoparticles and Its Reducing Agent from Cinnamon Bark Extract
by Araceli Granja Alvear, Nayely Pineda-Aguilar, Patricia Lozano, Cristóbal Lárez-Velázquez, Gottfried Suppan, Salomé Galeas, Alexis Debut, Karla Vizuete, Lola De Lima, Juan Pablo Saucedo-Vázquez, Frank Alexis and Floralba López
Bioengineering 2024, 11(5), 517; https://doi.org/10.3390/bioengineering11050517 (registering DOI) - 20 May 2024
Abstract
Synthesis of silver nanoparticles with antibacterial properties using a one-pot green approach that harnesses the natural reducing and capping properties of cinnamon (Cinnamomum verum) bark extract is presented in this work. Silver nitrate was the sole chemical reagent employed in this [...] Read more.
Synthesis of silver nanoparticles with antibacterial properties using a one-pot green approach that harnesses the natural reducing and capping properties of cinnamon (Cinnamomum verum) bark extract is presented in this work. Silver nitrate was the sole chemical reagent employed in this process, acting as the precursor salt. Gas Chromatography-Mass Spectroscopy (GC-MS), High-Performance Liquid Chromatography (HPLC) analysis, and some phytochemical tests demonstrated that cinnamaldehyde is the main component in the cinnamon bark extract. The resulting bio-reduced silver nanoparticles underwent comprehensive characterization by Ultraviolet–Vis (UV-Vis) and Fourier Transform InfraRed spectrophotometry (FTIR), Dynamic Light Scattering (DLS), Transmission Electron Microscopy, and Scanning Electron Microscopy suggesting that cinnamaldehyde was chemically oxidated to produce silver nanoparticles. These cinnamon-extract-based silver nanoparticles (AgNPs-cinnamon) displayed diverse morphologies ranging from spherical to prismatic shapes, with sizes spanning between 2.94 and 65.1 nm. Subsequently, the antibacterial efficacy of these nanoparticles was investigated against Klebsiella, E. Coli, Pseudomonas, Staphylococcus aureus, and Acinetobacter strains. The results suggest the promising potential of silver nanoparticles obtained (AgNPs-cinnamon) as antimicrobial agents, offering a new avenue in the fight against bacterial infections. Full article
(This article belongs to the Section Nanotechnology Applications in Bioengineering)
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25 pages, 4991 KiB  
Article
Structural and Organizational Strategies of Locomotor Modules during Landing in Patients with Chronic Ankle Instability
by Tianle Jie, Datao Xu, Zanni Zhang, Ee-Chon Teo, Julien S. Baker, Huiyu Zhou and Yaodong Gu
Bioengineering 2024, 11(5), 518; https://doi.org/10.3390/bioengineering11050518 (registering DOI) - 20 May 2024
Abstract
Background: Human locomotion involves the coordinated activation of a finite set of modules, known as muscle synergy, which represent the motor control strategy of the central nervous system. However, most prior studies have focused on isolated muscle activation, overlooking the modular organization of [...] Read more.
Background: Human locomotion involves the coordinated activation of a finite set of modules, known as muscle synergy, which represent the motor control strategy of the central nervous system. However, most prior studies have focused on isolated muscle activation, overlooking the modular organization of motor behavior. Therefore, to enhance comprehension of muscle coordination dynamics during multi-joint movements in chronic ankle instability (CAI), exploring muscle synergies during landing in CAI patients is imperative. Methods: A total of 22 patients with unilateral CAI and 22 healthy participants were recruited for this research. We employed a recursive model for second-order differential equations to process electromyographic (EMG) data after filtering preprocessing, generating the muscle activation matrix, which was subsequently inputted into the non-negative matrix factorization model for extraction of the muscle synergy. Muscle synergies were classified utilizing the K-means clustering algorithm and Pearson correlation coefficients. Statistical parameter mapping (SPM) was employed for temporal modular parameter analyses. Results: Four muscle synergies were identified in both the CAI and healthy groups. In Synergy 1, only the gluteus maximus showed significantly higher relative weight in CAI compared to healthy controls (p = 0.0035). Synergy 2 showed significantly higher relative weights for the vastus lateralis in the healthy group compared to CAI (p = 0.018), while in Synergy 4, CAI demonstrated significantly higher relative weights of the vastus lateralis compared to healthy controls (p = 0.030). Furthermore, in Synergy 2, the CAI group exhibited higher weights of the tibialis anterior compared to the healthy group (p = 0.042). Conclusions: The study suggested that patients with CAI exhibit a comparable modular organizational framework to the healthy group. Investigation of amplitude adjustments within the synergy spatial module shed light on the adaptive strategies employed by the tibialis anterior and gluteus maximus muscles to optimize control strategies during landing in patients with CAI. Variances in the muscle-specific weights of the vastus lateralis across movement modules reveal novel biomechanical adaptations in CAI, offering valuable insights for refining rehabilitation protocols. Full article
(This article belongs to the Special Issue Advances in Trauma and Injury Biomechanics)
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18 pages, 952 KiB  
Article
Make-or-Buy Policy Decision in Maintenance Planning for Mobility: A Multi-Criteria Approach
by Tommaso Ortalli, Andrea Di Martino, Michela Longo and Dario Zaninelli
Logistics 2024, 8(2), 55; https://doi.org/10.3390/logistics8020055 (registering DOI) - 20 May 2024
Abstract
The ongoing technical innovation is fully involving transportation sector, converting the usual mass-transit system toward a sustainable mobility. Make-or-buy decision are usually adopted to assess different solutions in terms of costs-benefits to put in place strategic choices regarding in-house production or from an [...] Read more.
The ongoing technical innovation is fully involving transportation sector, converting the usual mass-transit system toward a sustainable mobility. Make-or-buy decision are usually adopted to assess different solutions in terms of costs-benefits to put in place strategic choices regarding in-house production or from an external supplier. This can also be reflected on maintenance operations, thus replicating a similar approach to transport companies involved. This paper aims to present a decision-making model by means of a multi-criteria analysis to lead make-or-buy choices adapted to maintenance. A brief introduction into the actual mobility context is provided, evaluating global and national trends with respect to the mobility solutions offered. Then, a focus is set on maintenance approaches in mobility sector and the need of a make-or-buy decision process is considered. The decision-making path is developed through a multi-criteria framework based on eigenvector weighing assessment, where different Key Performance Indicators (KPIs) are identified and exploited to assess the maintenance approach at stake. Results allow to compare the solution offered by the different scenarios considered. In particular, for the case study of interest a −35% decrease in maintenance specific cost and −44% in cost variability were found. Reliability of the fleet was kept at an acceptable level compared to the reference in-house maintenance (≥90%) while an increase in the Mean Time Between Failure was observed. For the purposes of a small company, the method can address the choice of outsourcing maintenance as the best. Finally, a general trend is then extrapolated from the analysis performed, in order to constitute a decision guideline. Full article
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13 pages, 6278 KiB  
Article
Experimental Study on Evolution of Chemical Structure Defects and Secondary Contaminative Deposition during HF-Based Etching
by Xiao Shen, Feng Shi, Shuo Qiao, Xing Peng and Ying Xiong
Photonics 2024, 11(5), 479; https://doi.org/10.3390/photonics11050479 (registering DOI) - 20 May 2024
Abstract
Post-processing based on HF etching has become a highly preferred technique in the fabrication of fused silica optical elements in various high-power laser systems. Previous studies have thoroughly examined and confirmed the elimination of fragments and contamination. However, limited attention has been paid [...] Read more.
Post-processing based on HF etching has become a highly preferred technique in the fabrication of fused silica optical elements in various high-power laser systems. Previous studies have thoroughly examined and confirmed the elimination of fragments and contamination. However, limited attention has been paid to nano-sized chemical structural defects and secondary precursors that arise during the etching process. Therefore, in this paper, a set of fused silica samples are prepared and undergo the etching process under different parameters. Subsequently, an atomic force microscope, scanning electron microscope and fluorescence spectrometer are applied to analyze sample surfaces, and then an LIDT test based on the R-on-1 method is applied. The findings revealed that appropriate etching configurations will lead to certain LIDT improvement (from initial 7.22 J/cm2 to 10.76 J/cm2), and HF-based etching effectively suppresses chemical structural defects, while additional processes are recommended for the elimination of micron- to nano-sized secondary deposition contamination. Full article
(This article belongs to the Special Issue New Perspectives in Optical Design)
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9 pages, 4244 KiB  
Article
Carbon Dot-Decorated Polystyrene Microspheres for Whispering-Gallery Mode Biosensing
by Anton A. Starovoytov, Evgeniia O. Soloveva, Kamilla Kurassova, Kirill V. Bogdanov, Irina A. Arefina, Natalia N. Shevchenko, Tigran A. Vartanyan, Daler R. Dadadzhanov and Nikita A. Toropov
Photonics 2024, 11(5), 480; https://doi.org/10.3390/photonics11050480 (registering DOI) - 20 May 2024
Abstract
Whispering gallery mode (WGM) resonators doped with fluorescent materials find impressive applications in biological sensing. They do not require special conditions for the excitation of WGM inside that provide the basis for in vivo sensing. Currently, the problem of materials for in vivo [...] Read more.
Whispering gallery mode (WGM) resonators doped with fluorescent materials find impressive applications in biological sensing. They do not require special conditions for the excitation of WGM inside that provide the basis for in vivo sensing. Currently, the problem of materials for in vivo WGM sensors are substantial since their fluorescence should have stable optical properties as well as they should be biocompatible. To address this we present WGM microresonators of 5–7 μm, where the dopant is made of carbon quantum dots (CDs). CDs are biocompatible since they are produced from carbon and demonstrate bright optical emission, which shows different bands depending on the excitation wavelength. The WGM sensors developed here were tested as label-free biosensors by detecting bovine serum albumin molecules. The results showed WGM frequency shifting, with the limit of detection down to 1016 M level. Full article
(This article belongs to the Special Issue Advancements in Optical Metamaterials)
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15 pages, 3310 KiB  
Article
Training a Dataset Simulated Using RGB Images for an End-to-End Event-Based DoLP Recovery Network
by Changda Yan, Xia Wang, Xin Zhang, Conghe Wang, Qiyang Sun and Yifan Zuo
Photonics 2024, 11(5), 481; https://doi.org/10.3390/photonics11050481 (registering DOI) - 20 May 2024
Abstract
Event cameras are bio-inspired neuromorphic sensors that have emerged in recent years, with advantages such as high temporal resolutions, high dynamic ranges, low latency, and low power consumption. Event cameras can be used to build event-based imaging polarimeters, overcoming the limited frame rates [...] Read more.
Event cameras are bio-inspired neuromorphic sensors that have emerged in recent years, with advantages such as high temporal resolutions, high dynamic ranges, low latency, and low power consumption. Event cameras can be used to build event-based imaging polarimeters, overcoming the limited frame rates and low dynamic ranges of existing systems. Since events cannot provide absolute brightness intensity in different angles of polarization (AoPs), degree of linear polarization (DoLP) recovery in non-division-of-time (non-DoT) event-based imaging polarimeters is an ill-posed problem. Thus, we need a data-driven deep learning approach. Deep learning requires large amounts of data for training, and constructing a dataset for event-based non-DoT imaging polarimeters requires significant resources, scenarios, and time. We propose a method for generating datasets using simulated polarization distributions from existing red–green–blue images. Combined with event simulator V2E, the proposed method can easily construct large datasets for network training. We also propose an end-to-end event-based DoLP recovery network to solve the problem of DoLP recovery using event-based non-DoT imaging polarimeters. Finally, we construct a division-of-time event-based imaging polarimeter simulating an event-based four-channel non-DoT imaging polarimeter. Using real-world polarization events and DoLP ground truths, we demonstrate the effectiveness of the proposed simulation method and network. Full article
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11 pages, 2797 KiB  
Communication
Sensing Characteristic Analysis of All-Dielectric Metasurfaces Based on Fano Resonance in Near-Infrared Regime
by Yongpeng Zhao, Qingfubo Geng, Jian Liu and Zhaoxin Geng
Photonics 2024, 11(5), 482; https://doi.org/10.3390/photonics11050482 (registering DOI) - 20 May 2024
Abstract
A novel, all-dielectric metasurface, featuring a missing wedge-shaped nanodisk, is proposed to investigate optical characteristics. By introducing symmetry-breaking to induce Fano resonance, the metasurface achieves an impressive Q-factor of 1202 in the near-infrared spectrum, with a remarkably narrow full width at half maximum [...] Read more.
A novel, all-dielectric metasurface, featuring a missing wedge-shaped nanodisk, is proposed to investigate optical characteristics. By introducing symmetry-breaking to induce Fano resonance, the metasurface achieves an impressive Q-factor of 1202 in the near-infrared spectrum, with a remarkably narrow full width at half maximum (FWHM) of less than 1 nm. The ability to adjust the wavelength resonance by manipulating the structure of the wedge-shaped nanodisk offers a simple and efficient approach for metasurface design. This breakthrough holds great potential for various applications in sensing and optical filtering, marking a significant advancement in the field of nanophotonics. Full article
(This article belongs to the Special Issue Advanced Photonic Sensing and Measurement II)
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18 pages, 7516 KiB  
Article
Design Method of Cam Steering Mechanism Based on Path Fitting
by Xiaofei Zheng, Hantao Zhao, Songhui Zhang, Dan Liu and Binrui Wang
Processes 2024, 12(5), 1037; https://doi.org/10.3390/pr12051037 (registering DOI) - 20 May 2024
Abstract
In order to improve the accuracy of a solar-powered punch card car’s movement on a designated route and reduce positional deviations during its operation, a solar-powered punch card car with a single cam as the steering guidance mechanism was designed. The car adopts [...] Read more.
In order to improve the accuracy of a solar-powered punch card car’s movement on a designated route and reduce positional deviations during its operation, a solar-powered punch card car with a single cam as the steering guidance mechanism was designed. The car adopts a three-wheel structure. The transmission mechanism, steering mechanism, driving mechanism, and regulating mechanism of the car were analyzed. The kinematics model of the car was established and the motion characteristics of the car were obtained. By analyzing the relationship between the steering angle of the car and the curvature radius of its travel route, the front wheel angle of the car at each position was calculated using MATLAB R2020a. This allowed us to establish the relationship between the front wheel angle and the displacement of the steering push rod, which was further converted into the theoretical contour line of the cam. Subsequently, the theoretical contour line of the cam was completed and envelope correction was performed. Finally, through mechanical analysis and experimental verification using a prototype, the results indicated that the single-cam steering guidance mechanism calculated using this fast path fitting method exhibited excellent mechanical performance and a smooth and accurate trajectory, and the traveling path of the theoretical cam contour curve was basically consistent with the actual trajectory route. Full article
(This article belongs to the Section Advanced Digital and Other Processes)
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19 pages, 2968 KiB  
Article
Teaching–Learning-Based Optimization Algorithm with Stochastic Crossover Self-Learning and Blended Learning Model and Its Application
by Yindi Ma, Yanhai Li and Longquan Yong
Mathematics 2024, 12(10), 1596; https://doi.org/10.3390/math12101596 (registering DOI) - 20 May 2024
Abstract
This paper presents a novel variant of the teaching–learning-based optimization algorithm, termed BLTLBO, which draws inspiration from the blended learning model, specifically designed to tackle high-dimensional multimodal complex optimization problems. Firstly, the perturbation conditions in the “teaching” and “learning” stages of the original [...] Read more.
This paper presents a novel variant of the teaching–learning-based optimization algorithm, termed BLTLBO, which draws inspiration from the blended learning model, specifically designed to tackle high-dimensional multimodal complex optimization problems. Firstly, the perturbation conditions in the “teaching” and “learning” stages of the original TLBO algorithm are interpreted geometrically, based on which the search capability of the TLBO is enhanced by adjusting the range of values of random numbers. Second, a strategic restructuring has been ingeniously implemented, dividing the algorithm into three distinct phases: pre-course self-study, classroom blended learning, and post-course consolidation; this structural reorganization and the random crossover strategy in the self-learning phase effectively enhance the global optimization capability of TLBO. To evaluate its performance, the BLTLBO algorithm was tested alongside seven distinguished variants of the TLBO algorithm on thirteen multimodal functions from the CEC2014 suite. Furthermore, two excellent high-dimensional optimization algorithms were added to the comparison algorithm and tested in high-dimensional mode on five scalable multimodal functions from the CEC2008 suite. The empirical results illustrate the BLTLBO algorithm’s superior efficacy in handling high-dimensional multimodal challenges. Finally, a high-dimensional portfolio optimization problem was successfully addressed using the BLTLBO algorithm, thereby validating the practicality and effectiveness of the proposed method. Full article
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12 pages, 905 KiB  
Article
Comparative Evaluation of Dental Enamel Microhardness Following Various Methods of Interproximal Reduction: A Vickers Hardness Tester Investigation
by Dan-Cosmin Serbanoiu, Aurel-Claudiu Vartolomei, Dana-Valentina Ghiga, Silvia Izabella Pop, Irinel Panainte, Marioara Moldovan, Codruta Sarosi, Ioan Petean, Marie-Jose Boileau and Mariana Pacurar
Biomedicines 2024, 12(5), 1132; https://doi.org/10.3390/biomedicines12051132 (registering DOI) - 20 May 2024
Abstract
Interproximal enamel reduction, also known as stripping, is a common orthodontic procedure that reduces the mesiodistal diameter of teeth, allowing for a balance of available space in dental arches. The aim of this study was to assess the enamel surface microhardness resulting from [...] Read more.
Interproximal enamel reduction, also known as stripping, is a common orthodontic procedure that reduces the mesiodistal diameter of teeth, allowing for a balance of available space in dental arches. The aim of this study was to assess the enamel surface microhardness resulting from the application of currently available methods for interproximal reduction. Forty-two extracted human permanent teeth were divided into six different groups, each subjected to a therapeutic stripping procedure using various methods (i.e., diamond burs, abrasive strips of 90 μm, 60 μm, 40 μm, and 15 μm, and abrasive discs). Stripping was performed by a single individual in accordance with the manufacturers’ recommendations for the various systems used. One of the proximal faces of the tooth underwent IPR, while the other side remained untreated for control. The hardness of the enamel surface was measured using a Vickers hardness tester. The control group achieved the hardest enamel surface (354.4 ± 41.02 HV1), while the lowest was observed for enamel surfaces treated with 90 µm abrasive strips (213.7 ± 118.6). The only statistically significant difference was identified in comparisons between the values measured for the control group and those obtained after stripping with diamond burs (p = 0.0159). Enamel microhardness varied depending on the stripping instrument used, but no statistically significant differences were found (p > 0.05). Optimal microhardness values, close to those of healthy enamel, were achieved after mechanical treatment with 15 µm abrasive strips and abrasive discs. Dental stripping is a safe therapeutic procedure that has a relatively minor influence on the microhardness of surface enamel. Full article
(This article belongs to the Section Molecular and Translational Medicine)
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19 pages, 722 KiB  
Article
Secure Active Intelligent Reflecting Surface Communication against Colluding Eavesdroppers
by Jiaxin Xu, Yuyang Peng, Runlong Ye, Wei Gan, Fawaz AL-Hazemi and Mohammad Meraj Mirza
Mathematics 2024, 12(10), 1597; https://doi.org/10.3390/math12101597 (registering DOI) - 20 May 2024
Abstract
An active intelligent reflecting surface (IRS)-assisted, secure, multiple-input–single-output communication method is proposed in this paper. In this proposed scheme, a practical and unfavorable propagation environment is considered by assuming that multiple colluding eavesdroppers (Eves) coexist. In this case, we jointly optimize the beamformers [...] Read more.
An active intelligent reflecting surface (IRS)-assisted, secure, multiple-input–single-output communication method is proposed in this paper. In this proposed scheme, a practical and unfavorable propagation environment is considered by assuming that multiple colluding eavesdroppers (Eves) coexist. In this case, we jointly optimize the beamformers of the base station (BS) and the active IRS for the formulated sum secrecy rate (SSR) maximization problem. Because the formulated problem is not convex, we apply the alternating optimization method to optimize the beamformers for maximizing the SSR. Specifically, we use the semi-definite relaxation method to solve the sub-problem of the beamforming vector of the BS, and we use the successive convex approximation method to solve the sub-problem of the power amplification matrix of the active IRS. Based on the solutions obtained using these stated methods, numerical results show that deploying an active IRS is superior compared to the cases of a passive IRS and a non-IRS for improving the physical layer security of wireless communication with multiple colluding Eves under different settings, such as the numbers of users, Eves, reflecting elements, and BS antennas as well as the maximum transmit power budget at the BS. Full article
16 pages, 493 KiB  
Article
The Effects of Interest Rates on Bank Risk-Taking in South Africa: Do Cyclical and Location Asymmetries Matter?
by Clement Moyo and Andrew Phiri
Int. J. Financial Stud. 2024, 12(2), 49; https://doi.org/10.3390/ijfs12020049 (registering DOI) - 20 May 2024
Abstract
We examine the nonlinear relationship between interest rates on bank risk-taking behavior in South Africa between 2008:q1 and 2022:q3 using nonlinear autoregressive distributive lag (NARDL) and quantile autoregressive distributive lag (QARDL) models. Whilst the preliminary estimates from linear ARDL produce results adhering to [...] Read more.
We examine the nonlinear relationship between interest rates on bank risk-taking behavior in South Africa between 2008:q1 and 2022:q3 using nonlinear autoregressive distributive lag (NARDL) and quantile autoregressive distributive lag (QARDL) models. Whilst the preliminary estimates from linear ARDL produce results adhering to conventional theory, the NARDL and QARDL analysis shows that the relationship between the variables is more complex. On one hand, the NARDL model shows that the phase of monetary policy (cyclical asymmetries) is important in determining the pass-through effects of interest rates on bank risk behavior. We find that both contractionary and expansionary monetary policy increases long-term risk through decreased liquidity for the former and increased non-performing loans for the latter. On the other hand, the QARDL model shows that the level of bank risk behavior (location asymmetries) is also important in determining the impact of interest rates on bank risk behavior. We find that interest rates affect bank risk behavior in ‘medium-to-high risk environments’ for unsecured loans and lending and in ‘medium-to-low risk environments’ for liquidity. Overall, these results enable us to recommend ways in which the SARB can strengthen its monitoring mechanisms given the multifaceted impact of interest rates on bank risk-taking. Full article
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14 pages, 1338 KiB  
Article
Enhanced Efficacy of Ciprofloxacin and Tobramycin against Staphylococcus aureus When Combined with Corydalis Tuber and Berberine through Efflux Pump Inhibition
by Yena Seo, Minjun Kim and Tae-Jong Kim
Antibiotics 2024, 13(5), 469; https://doi.org/10.3390/antibiotics13050469 (registering DOI) - 20 May 2024
Abstract
One way that bacteria develop antibiotic resistance is by reducing intracellular antibiotic concentrations through efflux pumps. Therefore, enhancing the efficacy of antibiotics using efflux pump inhibitors provides a way to overcome this type of resistance. Notably, an increasing number of pathogenic Staphylococcus aureus [...] Read more.
One way that bacteria develop antibiotic resistance is by reducing intracellular antibiotic concentrations through efflux pumps. Therefore, enhancing the efficacy of antibiotics using efflux pump inhibitors provides a way to overcome this type of resistance. Notably, an increasing number of pathogenic Staphylococcus aureus strains have efflux pump genes. In this study, the extract from Corydalis ternata Nakai tuber (Corydalis Tuber) at 512 mg/L was demonstrated to have an antibiotic synergistic effect with ciprofloxacin at 2 mg/L and tobramycin at 1024 mg/L against methicillin-resistant S. aureus (MRSA). Berberine, an isoquinoline alkaloid identified in Corydalis Tuber, was identified as contributing to this effect. Ethidium bromide efflux pump activity assays showed that Corydalis Tuber extract and berberine inhibited efflux, suggesting that they are efflux pump inhibitors. Molecular docking simulations suggested that berberine binds to S. aureus efflux pump proteins MepA, NorA, NorB, and SdrM. Additionally, berberine and Corydalis Tuber extract inhibit biofilm formation, which can confer antibiotic resistance. This study’s findings suggest that Corydalis Tuber, a traditional herbal medicine, and berberine, a medicinal supplement, act as S. aureus efflux pump inhibitors, synergistically increasing the efficacy of ciprofloxacin and tobramycin and showing promise as a treatment for antibiotic-resistant S. aureus infections, including MRSA. Full article
(This article belongs to the Special Issue Advance in Natural Products: Potential Antimicrobial Targets)
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34 pages, 10912 KiB  
Article
The Influence of Zinc Oxide Nanoparticles and Salt Stress on the Morphological and Some Biochemical Characteristics of Solanum lycopersicum L. Plants
by Mostafa Ahmed, Diaa Attia Marrez, Roquia Rizk, Mostafa Zedan, Donia Abdul-Hamid, Kincső Decsi, Gergő Péter Kovács and Zoltán Tóth
Plants 2024, 13(10), 1418; https://doi.org/10.3390/plants13101418 (registering DOI) - 20 May 2024
Abstract
Salinity reduces crop yields and quality, causing global economic losses. Zinc oxide nanoparticles (ZnO-NPs) improve plant physiological and metabolic processes and abiotic stress resistance. This study examined the effects of foliar ZnO-NPs at 75 and 150 mg/L on tomato Kecskeméti 549 plants to [...] Read more.
Salinity reduces crop yields and quality, causing global economic losses. Zinc oxide nanoparticles (ZnO-NPs) improve plant physiological and metabolic processes and abiotic stress resistance. This study examined the effects of foliar ZnO-NPs at 75 and 150 mg/L on tomato Kecskeméti 549 plants to alleviate salt stress caused by 150 mM NaCl. The precipitation procedure produced ZnO-NPs that were characterized using UV-VIS, TEM, STEM, DLS, EDAX, Zeta potential, and FTIR. The study assessed TPCs, TFCs, total hydrolyzable sugars, total free amino acids, protein, proline, H2O2, and MDA along with plant height, stem width, leaf area, and SPAD values. The polyphenolic burden was also measured by HPLC. With salt stress, plant growth and chlorophyll content decreased significantly. The growth and development of tomato plants changed by applying the ZnO-NPs. Dosages of ZnO-NPs had a significant effect across treatments. ZnO-NPs also increased chlorophyll, reduced stress markers, and released phenolic chemicals and proteins in the leaves of tomatoes. ZnO-NPs reduce salt stress by promoting the uptake of minerals. ZnO-NPs had beneficial effects on tomato plants when subjected to salt stress, making them an alternate technique to boost resilience in saline soils or low-quality irrigation water. This study examined how foliar application of chemically synthesized ZnO-NPs to the leaves affected biochemistry, morphology, and phenolic compound synthesis with and without NaCl. Full article
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