The 2023 MDPI Annual Report has
been released!
 
40 pages, 12153 KiB  
Review
Antimicrobial Activity of Arthrospira (Former Spirulina) and Dunaliella Related to Recognized Antimicrobial Bioactive Compounds
by Yana Ilieva, Maya Margaritova Zaharieva, Hristo Najdenski and Alexander Dimitrov Kroumov
Int. J. Mol. Sci. 2024, 25(10), 5548; https://doi.org/10.3390/ijms25105548 (registering DOI) - 19 May 2024
Abstract
With the increasing rate of the antimicrobial resistance phenomenon, natural products gain our attention as potential drug candidates. Apart from being used as nutraceuticals and for biotechnological purposes, microalgae and phytoplankton have well-recognized antimicrobial compounds and proved anti-infectious potential. In this review, we [...] Read more.
With the increasing rate of the antimicrobial resistance phenomenon, natural products gain our attention as potential drug candidates. Apart from being used as nutraceuticals and for biotechnological purposes, microalgae and phytoplankton have well-recognized antimicrobial compounds and proved anti-infectious potential. In this review, we comprehensively outline the antimicrobial activity of one genus of cyanobacteria (Arthrospira, formerly Spirulina) and of eukaryotic microalgae (Dunaliella). Both, especially Arthrospira, are mostly used as nutraceuticals and as a source of antioxidants for health supplements, cancer therapy and cosmetics. Their diverse bioactive compounds provide other bioactivities and potential for various medical applications. Their antibacterial and antifungal activity vary in a broad range and are strain specific. There are strains of Arthrospira platensis with very potent activity and minimum inhibitory concentrations (MICs) as low as 2–15 µg/mL against bacterial fish pathogens including Bacillus and Vibrio spp. Arthrospira sp. has demonstrated an inhibition zone (IZ) of 50 mm against Staphylococcus aureus. Remarkable is the substantial amount of in vivo studies of Arthrospira showing it to be very promising for preventing vibriosis in shrimp and Helicobacter pylori infection and for wound healing. The innovative laser irradiation of the chlorophyll it releases can cause photodynamic destruction of bacteria. Dunaliella salina has exhibited MIC values lower than 300 µg/mL and an IZ value of 25.4 mm on different bacteria, while Dunaliella tertiolecta has demonstrated MIC values of 25 and 50 μg/mL against some Staphylococcus spp. These values fulfill the criteria for significant antimicrobial activity and sometimes are comparable or exceed the activity of the control antibiotics. The bioactive compounds which are responsible for that action are fatty acids including PUFAs, polysaccharides, glycosides, peptides, neophytadiene, etc. Cyanobacteria, such as Arthrospira, also particularly have antimicrobial flavonoids, terpenes, alkaloids, saponins, quinones and some unique-to-them compounds, such as phycobiliproteins, polyhydroxybutyrate, the peptide microcystin, etc. These metabolites can be optimized by using stress factors in a two-step process of fermentation in closed photobioreactors (PBRs). Full article
(This article belongs to the Special Issue Current Research in Antimicrobial Natural Products)
Show Figures

Figure 1

15 pages, 7087 KiB  
Article
Preparation and Performance of a Novel ZnO/TM/PET Composite Negative Ion Functional Fiber
by Mengxin Zhang, Jishu Zhang, Xin Lu, Jianbing Wu, Jiajia Peng, Wei Wang and Jin Tao
Polymers 2024, 16(10), 1439; https://doi.org/10.3390/polym16101439 (registering DOI) - 19 May 2024
Abstract
Using zinc oxide (ZnO), tourmaline (TM), and polyethylene terephthalate (PET) as main raw materials, a novel ZnO/TM/PET negative ion functional fiber was created. The rheological properties of a ZnO/TM/PET masterbatch were investigated; the morphology, XRD, and FT-IR of the fibers were observed; and [...] Read more.
Using zinc oxide (ZnO), tourmaline (TM), and polyethylene terephthalate (PET) as main raw materials, a novel ZnO/TM/PET negative ion functional fiber was created. The rheological properties of a ZnO/TM/PET masterbatch were investigated; the morphology, XRD, and FT-IR of the fibers were observed; and the mechanical properties, thermal properties, and negative ion release properties of the new fiber were tested. The results showed that the average particle size of the ZnO/TM composite is nearly 365 nm, with an increase in negative ion emission efficiency by nearly 50% compared to the original TM. The apparent viscosity of fiber masterbatch decreases with the increase in the addition of the ZnO/TM composite, and the rheological properties of the PET fiber masterbatch are not significantly effected, still showing shear thinning characteristics when the amount of addition reaches 10%. The ZnO/TM composite disperses well in the interior and surface of the ZnO/TM/PET fiber matrix. The prepared ZnO/TM/PET fiber has excellent properties, such as fineness of 1.54 dtex, glass transition temperature of 122.4 °C, fracture strength of 3.31 cN/dtex, and negative ion release of 1640/cm3, which shows great industrialization potential. Full article
(This article belongs to the Special Issue Advances in Polymer Fiber and Textiles)
Show Figures

Figure 1

12 pages, 1097 KiB  
Article
Improving Microalgae Feasibility Cultivation: Preliminary Results on Exhausted Medium Reuse Strategy
by Luigi Marra, Elena Aurino, Francesca Raganati, Antonino Pollio and Antonio Marzocchella
Processes 2024, 12(5), 1029; https://doi.org/10.3390/pr12051029 (registering DOI) - 19 May 2024
Abstract
Although microalgae exploitation is very promising, process sustainability is undermined by biomass production and harvesting. Among the various bottlenecks of the production process, particular attention should be paid to the water footprint. Indeed, a huge volume of water is required in microalgae production. [...] Read more.
Although microalgae exploitation is very promising, process sustainability is undermined by biomass production and harvesting. Among the various bottlenecks of the production process, particular attention should be paid to the water footprint. Indeed, a huge volume of water is required in microalgae production. Water reuse can support both the water footprint and medium cost reduction, saving water and unconverted substrates. The present study reports preliminary results regarding the utilization of a water reuse strategy for two Chlorophyta microalgae under batch conditions. Growth parameters and chlorophyll content are monitored and the optimal amount of reused medium is assessed. The results show that 70% of the medium can be reused with no loss of specific growth rate and chlorophyll fraction for Pseudococcomyxa simplex in three consecutive batch cultivations. By contrast, a significant decline in Chlorella vulgaris growth was observed after the first cultivation in reused medium, across all tested conditions. Full article
18 pages, 7832 KiB  
Article
Accelerating Conjugate Heat Transfer Simulations in Squared Heated Cavities through Graphics Processing Unit (GPU) Computing
by César Augusto Borges da Silva Reis, Daniel Botezelli, Arthur Mendonça de Azevedo, Elisan dos Santos Magalhães and Aristeu da Silveira Neto
Computation 2024, 12(5), 106; https://doi.org/10.3390/computation12050106 (registering DOI) - 19 May 2024
Abstract
This research develops an innovative framework for accelerating Conjugate Heat Transfer (CHT) simulations within squared heated cavities through the application of Graphics Processing Units (GPUs). Although leveraging GPUs for computational speed improvements is well recognized, this study distinguishes itself by formulating a tailored [...] Read more.
This research develops an innovative framework for accelerating Conjugate Heat Transfer (CHT) simulations within squared heated cavities through the application of Graphics Processing Units (GPUs). Although leveraging GPUs for computational speed improvements is well recognized, this study distinguishes itself by formulating a tailored optimization strategy utilizing the CUDA-C programming language. This approach is specifically designed to tackle the inherent challenges of modeling squared cavity configurations in thermal simulations. Comparative performance evaluations reveal that our GPU-accelerated framework reduces computation times by up to 99.7% relative to traditional mono-core CPU processing. More importantly, it demonstrates an increase in accuracy in heat transfer predictions compared to existing CPU-based models. These results highlight not only the technical feasibility but also the substantial enhancements in simulation efficiency and accuracy, which are crucial for critical engineering applications such as aerospace component design, electronic device cooling, and energy system optimization. By advancing GPU computational techniques, this work contributes significantly to the field of thermal management, offering a potential for broader application and paving the way for more efficient, sustainable engineering solutions. Full article
Show Figures

Figure 1

18 pages, 394 KiB  
Review
Parvalbumin Interneuron Dysfunction in Neurological Disorders: Focus on Epilepsy and Alzheimer’s Disease
by Beulah Leitch
Int. J. Mol. Sci. 2024, 25(10), 5549; https://doi.org/10.3390/ijms25105549 (registering DOI) - 19 May 2024
Abstract
Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their [...] Read more.
Parvalbumin expressing (PV+) GABAergic interneurons are fast spiking neurons that provide powerful but relatively short-lived inhibition to principal excitatory cells in the brain. They play a vital role in feedforward and feedback synaptic inhibition, preventing run away excitation in neural networks. Hence, their dysfunction can lead to hyperexcitability and increased susceptibility to seizures. PV+ interneurons are also key players in generating gamma oscillations, which are synchronized neural oscillations associated with various cognitive functions. PV+ interneuron are particularly vulnerable to aging and their degeneration has been associated with cognitive decline and memory impairment in dementia and Alzheimer’s disease (AD). Overall, dysfunction of PV+ interneurons disrupts the normal excitatory/inhibitory balance within specific neurocircuits in the brain and thus has been linked to a wide range of neurodevelopmental and neuropsychiatric disorders. This review focuses on the role of dysfunctional PV+ inhibitory interneurons in the generation of epileptic seizures and cognitive impairment and their potential as targets in the design of future therapeutic strategies to treat these disorders. Recent research using cutting-edge optogenetic and chemogenetic technologies has demonstrated that they can be selectively manipulated to control seizures and restore the balance of neural activity in the brains of animal models. This suggests that PV+ interneurons could be important targets in developing future treatments for patients with epilepsy and comorbid disorders, such as AD, where seizures and cognitive decline are directly linked to specific PV+ interneuron deficits. Full article
(This article belongs to the Special Issue Latest Review Papers in Molecular Neurobiology 2024)
36 pages, 11021 KiB  
Review
Nano-Enhanced Phase Reinforced Magnesium Matrix Composites: A Review of the Matrix, Reinforcement, Interface Design, Properties and Potential Applications
by Jiao-Yi Ren, Guan-Cheng Ji, Hao-Rui Guo, Yu-Meng Zhou, Xin Tan, Wen-Fang Zheng, Qian Xing, Jia-Yi Zhang, Jing-Ran Sun, Hong-Yu Yang, Feng Qiu and Qi-Chuan Jiang
Materials 2024, 17(10), 2454; https://doi.org/10.3390/ma17102454 (registering DOI) - 19 May 2024
Abstract
Magnesium matrix composites are essential lightweight metal matrix composites, following aluminum matrix composites, with outstanding application prospects in automotive, aerospace lightweight and biomedical materials because of their high specific strength, low density and specific stiffness, good casting performance and rich resources. However, the [...] Read more.
Magnesium matrix composites are essential lightweight metal matrix composites, following aluminum matrix composites, with outstanding application prospects in automotive, aerospace lightweight and biomedical materials because of their high specific strength, low density and specific stiffness, good casting performance and rich resources. However, the inherent low plasticity and poor fatigue resistance of magnesium hamper its further application to a certain extent. Many researchers have tried many strengthening methods to improve the properties of magnesium alloys, while the relationship between wear resistance and plasticity still needs to be further improved. The nanoparticles added exhibit a good strengthening effect, especially the ceramic nanoparticles. Nanoparticle-reinforced magnesium matrix composites not only exhibit a high impact toughness, but also maintain the high strength and wear resistance of ceramic materials, effectively balancing the restriction between the strength and toughness. Therefore, this work aims to provide a review of the state of the art of research on the matrix, reinforcement, design, properties and potential applications of nano-reinforced phase-reinforced magnesium matrix composites (especially ceramic nanoparticle-reinforced ones). The conventional and potential matrices for the fabrication of magnesium matrix composites are introduced. The classification and influence of ceramic reinforcements are assessed, and the factors influencing interface bonding strength between reinforcements and matrix, regulation and design, performance and application are analyzed. Finally, the scope of future research in this field is discussed. Full article
(This article belongs to the Special Issue High Performance Alloy and Its Nanocomposites)
Show Figures

Figure 1

8 pages, 2018 KiB  
Article
Early Single-Center Experience of DaVinci® Single-Port (SP) Robotic Surgery in Colorectal Patients
by Hye Jung Cho and Woo Ram Kim
J. Clin. Med. 2024, 13(10), 2989; https://doi.org/10.3390/jcm13102989 (registering DOI) - 19 May 2024
Abstract
Background: DaVinci® single-port (SP) robotic surgery offers several benefits compared to traditional multiport laparoscopic or robotic surgeries. One of the main advantages is that it allows for a minimally invasive approach, resulting in a single, smaller incision and reduced trauma to the [...] Read more.
Background: DaVinci® single-port (SP) robotic surgery offers several benefits compared to traditional multiport laparoscopic or robotic surgeries. One of the main advantages is that it allows for a minimally invasive approach, resulting in a single, smaller incision and reduced trauma to the patient’s body, leading to less postoperative pain, faster recovery, and reduced risk of complications. The cosmesis of a single port with minimal visible scarring is also an attractive aspect to the patients; however, many surgeons use an additional port for energy device, stapler use, and drain insertion. Pure single-port surgery with one incision is still rare. Here, we share our experience of our first 10 cases using the SP robotic platform in colorectal surgery. Methods: From May 2023 to December 2023, colorectal patients who underwent SP robotic surgery were analyzed. Placement of the incision was the umbilicus for eight patients, and right lower quadrant for two patients, through which ileostomy maturation was performed. Data on perioperative parameters and postoperative outcomes were analyzed, with a median follow-up of 4.6 months (range 0.6–7.4 months). Results: A total of 10 colorectal patients underwent DaVinci® single-port robotic colorectal surgery at our institution during this period. The patient demographic was four males (40%) and six females (60%) with a median age of 63.5 years (range 50–75 years). Median body mass index (BMI) was 22.89 kg/m2 (range 19.92–26.84 kg/m2). Nine patients were diagnosed with colorectal cancer, and one patient was diagnosed with a rectal gastrointestinal tumor. One patient underwent anterior resection and cholecystectomy simultaneously. Mean operation time was 222 min (range 142–316 min), and mean wound size was 3.25 cm (range 2.5–4.5 cm). Nine patients underwent surgery with single incision through which a single-port trocar was inserted, and one patient had one additional port for drain insertion. Mean hospital stay was 6 days (range 4–8 days) with one postoperative complication of bleeding requiring transfusion, but there was no readmission within 30 days. Conclusions: Overall, our experience with single-port robotic colorectal surgery has been promising. With only one patient with additional port for drain insertion, all nine patients underwent SP-robotic surgery with single incision for colon as well as rectal surgeries. Compared to an average postoperative length of stay of 6.5-8 days in laparoscopic colorectal surgeries reported in literature, SP-robotic surgery 33showed faster recovery of 6 days highlighting its benefits in patient recovery and satisfaction. Full article
Show Figures

Figure 1

10 pages, 8804 KiB  
Article
A Peel Test Method to Characterize the Decay Law of Prepreg Tape Tack at Different Temperatures
by Jiaqi Shi, Wang Wang, Yuequan Wang, Junwei Qi and Jun Xiao
Materials 2024, 17(10), 2449; https://doi.org/10.3390/ma17102449 (registering DOI) - 19 May 2024
Abstract
The tack of prepreg is a key factor affecting the automatic tape laying process. During the manufacturing process of large composite parts, prepreg material may be stored at room temperature for several days, resulting in a decrease in its tack. In this study, [...] Read more.
The tack of prepreg is a key factor affecting the automatic tape laying process. During the manufacturing process of large composite parts, prepreg material may be stored at room temperature for several days, resulting in a decrease in its tack. In this study, a new tack test tool was designed, and the decay rate of prepreg tack at different temperatures was tested. We proposed a prepreg tack decay model, which assumes that the main factor in tack decay is the reduction in resin chain activity during storage. The maximum deviation between the model calculation results and the experimental results of the tack decay rate is 9.7%. This study also proposed a new statistical unit for prepreg tack, which can establish the relationship between the tack of prepreg and its remaining storage time and reduce prepreg management costs. Full article
Show Figures

Figure 1

11 pages, 2033 KiB  
Article
Towards Single-Polymer-Based Fully Printed Textile-Based Flexible Ag2O-Zn Battery for Wearable Electronics
by Akash Kota, Kavya Vallurupalli, Amy T. Neidhard-Doll and Vamsy P. Chodavarapu
Textiles 2024, 4(2), 256-266; https://doi.org/10.3390/textiles4020015 (registering DOI) - 19 May 2024
Abstract
Printed textile-based flexible batteries are gaining attention in several applications, but they are becoming more relevant to the health care industry in terms of realizing wearable and skin-conformable electronic devices. A flexible battery must ideally be deformable along multiple directions. In this work, [...] Read more.
Printed textile-based flexible batteries are gaining attention in several applications, but they are becoming more relevant to the health care industry in terms of realizing wearable and skin-conformable electronic devices. A flexible battery must ideally be deformable along multiple directions. In this work, with an aim to develop a fully printed omnidirectional deformable battery, we report the fabrication process of a novel single-polymer-based flexible non-rechargeable planar Ag2O-Zn battery on a textile substrate using the stencil printing method. Except for the electrolyte, all the components of the battery, including the current collectors, the anode, the cathode, and the separator membrane, are fabricated using a single polymer, namely styrene–ethylene–butylene–styrene (SEBS). To fabricate the SEBS separator, we introduce the solvent evaporation-induced phase separation (SEIPS) process. In the SEIPS method, toluene and dimethyl sulfoxide (DMSO) are selected as the solvent–nonsolvent pair. The SEBS: toluene: DMSO system with a wt% ratio of 6:85:9 showed improved performance regarding the OCV tests. A polyacrylic acid (PAA)-based alkaline polymer gel is used as an electrolyte. The demonstrated process is simple, and, with suitable modifications, it should find its use in the development of digitally printed alkaline batteries. Full article
(This article belongs to the Special Issue Advances in Smart Textiles)
Show Figures

Figure 1

16 pages, 6173 KiB  
Article
Diversity of Bacterial Communities in Sediment in Inland Water Bodies in Relation to Environmental Factors and Human Impacts: A Case Study on Typical Regions in Vietnam
by Hoa Thi Bui, Thuy Thi Thu Nguyen, Ha Thu Le, Dau Thi Pham, Huy Quang Nguyen, Nam Thanh Nguyen, Tam Duc Nguyen, Tam Thi Nguyen, Hoang Phuc Trinh, Cuong Van Duong and Hai The Pham
Microbiol. Res. 2024, 15(2), 864-879; https://doi.org/10.3390/microbiolres15020056 (registering DOI) - 19 May 2024
Abstract
Environmental changes and human impact can alter biodiversity in negative manners that affect mankind’s sustainable development. Particularly, such effects on inland waters are even more concerning, as those ecosystems play essential roles in sustaining human life as well as relevant wildlife. Thus, in [...] Read more.
Environmental changes and human impact can alter biodiversity in negative manners that affect mankind’s sustainable development. Particularly, such effects on inland waters are even more concerning, as those ecosystems play essential roles in sustaining human life as well as relevant wildlife. Thus, in this study, we investigated such effects on microbial diversity in inland waters in Vietnam using bacterial communities in sediment as indicators. To do this, we collected sediment samples from various locations in three respective regions (Red river in the north, Ba river in the central area, and Mekong delta flood zone in the south) using standard methods, extracted their total DNA, sequenced their V3-V4 16S rRNA gene fragments using an Illumina Miseq platform and analyzed the sequences to infer the diversity of the bacterial communities in the samples. These communities were compared in terms of richness (alpha diversity) and composition (beta diversity), and the correlations between their diversity levels and environmental factors, as well as human activities, were analyzed by using standard statistical tools. Our results showed that the communities were different from each other solely by region, in richness and critically in composition, although there were some communities distinctively different from all the others. Among environmental factors, only water salinity (and conductivity) had negative correlations with alpha-diversity indices of the bacterial communities, and phosphate concentration and turbidity had positive correlations, while the other factors had almost no correlations, which partially explains the region-specific diversity. These results also suggest that climate change incidences, especially sea intrusion, can have significant effects on microbial diversity in inland waters. The impact of human activities did not appear severe, solely affecting bacterial community richness, but not significantly affecting bacterial community composition. However, apparently reduced bacterial diversity in several sites with intense human impacts and distinct environmental conditions should be noted and deserve further investigation. Full article
40 pages, 4235 KiB  
Article
About the Possible Solar Nature of the ~200 yr (de Vries/Suess) and ~2000–2500 yr (Hallstadt) Cycles and Their Influences on the Earth’s Climate: The Role of Solar-Triggered Tectonic Processes in General “Sun–Climate” Relationship
by Boris Komitov
Atmosphere 2024, 15(5), 612; https://doi.org/10.3390/atmos15050612 (registering DOI) - 19 May 2024
Abstract
(1) Introduction: The subject of the present study concerns the analysis of the existence and long time evolution of the solar ~200 yr (de Vries/Suess) and ~2400 yr (Hallstadt) cycles during the recent part of the Wurm ice epoch and [...] Read more.
(1) Introduction: The subject of the present study concerns the analysis of the existence and long time evolution of the solar ~200 yr (de Vries/Suess) and ~2400 yr (Hallstadt) cycles during the recent part of the Wurm ice epoch and the Holocene, as well as their forcing on the regional East European climate during the last two calendar millennia. The results obtained here are compared with those from our previous studies, as well as with the results obtained by other authors and with other types of data. A possible scenario of solar activity changes during the 21st century, as well as different possible mechanisms of solar–climatic relationships, is discussed. (2) Data and methods: Two types of indirect (historical) data series for solar activity were used: (a) the international radiocarbon tree ring series (INTCAL13) for the last 13,900 years; (b) the Schove series of the calendar years of minima and maxima and the magnitudes of 156 quasi 11 yr sunspot Schwabe–Wolf cycles since 296 AD and up to the sunspot cycle with number 24 (SC24) in the Zurich series; (c) manuscript messages about extreme meteorological and climatic events (Danube and Black Sea near-coast water freezing), extreme summer droughts, etc., in Bulgaria and adjacent territories since 296 and up to 1899 AD, when the Bulgarian meteorological dataset was started. A time series analysis and χ2-test were used. (3) Results and analysis: The amplitude modulation of the 200 yr solar cycle by the 2400 yr (Hallstadt) cycle was confirmed. Two groups of extremely cold winters (ECWs) during the last ~1700 years were established. Both groups without exclusion are concentrated near 11 yr sunspot cycle extremes. The number of ECWs near sunspot cycle minima is about 2 times greater than that of ECWs near sunspot cycle maxima. This result is in agreement with our earlier studies for the instrumental epoch since 1899 AD. The driest “spring-summer-early autumn” seasons in Bulgaria and adjacent territories occur near the initial and middle phases of the grand solar minima of the Oort–Dalton type, which relate to the downward phases and minima of the 200 yr Suess cycle. (4) Discussion: The above results confirm the effect of the Sun’s forcing on climate. However, it cannot be explained by the standard hypothesis for total solar irradiation (TSI) variations. That is why another hypothesis is suggested by the author. The mechanism considered by Svensmark for galactic cosmic ray (GCR) forcing on aerosol nuclei was taken into account. However, in the hypothesis suggested here, the forcing of solar X-ray flux changes (including solar flares) on the low ionosphere (the D-layer) and following interactions with the Earth’s lithosphere due to the terrestrial electric current systems play a key role for aerosol nuclei and cloud generation and dynamics during sunspot maxima epochs. The GCR flux maximum absorption layer at heights of 35–40 km replaces the ionosphere D-layer role during the sunspot minima epochs. Full article
(This article belongs to the Special Issue The Influence of Solar Cyclicity on the Earth’s Climate)
Show Figures

Figure 1

20 pages, 7406 KiB  
Article
Coupled Meteo–Hydrodynamic Approach in Semi-Enclosed Basins and Sensitivity Assessment of Wind-Driven Current
by Elvira Armenio, Andrea Tateo, Francesca Fedele, Nicola Ungaro, Michele Mossa, Vittorio Esposito and Vincenzo Campanaro
Oceans 2024, 5(2), 292-311; https://doi.org/10.3390/oceans5020019 (registering DOI) - 19 May 2024
Abstract
A coupled numerical approach that combines the WRF model and the Mike 3 (DHI) hydrodynamic model was developed and applied in two semi-enclosed basins in the Ionian Sea (Italy) to assess the wind-driven current. To gain a better understanding of how the sea [...] Read more.
A coupled numerical approach that combines the WRF model and the Mike 3 (DHI) hydrodynamic model was developed and applied in two semi-enclosed basins in the Ionian Sea (Italy) to assess the wind-driven current. To gain a better understanding of how the sea current field can vary depending on meteorological data forcing, three different scenario were set up. The sensitivity of the sea current pattern was investigated as a function of the type of meteorological forcing and appreciating the differences in the results. The aims of this study are threefold. Firstly, we wish to define an ad hoc procedure to join the model-computed meteorological parameters in the hydrodynamic model. Secondly, we will investigate the feedback from the Mar Piccolo and Mar Grande basins in the Ionian Sea using fully coupled simulations and an uncoupled system where the atmospheric parameters are derived from a ground station. Finally, we will evaluate the results achieved by applying two scenarios of typical meteorological conditions to the study site. The model results highlighted the variability of sea currents depending on meteorological forcing. Full article
Show Figures

Figure 1

18 pages, 1430 KiB  
Article
Polycations as Aptamer-Binding Modulators for Sensitive Fluorescence Anisotropy Assay of Aflatoxin B1
by Alexey V. Samokhvalov, Alena A. Mironova, Sergei A. Eremin, Anatoly V. Zherdev and Boris B. Dzantiev
Sensors 2024, 24(10), 3230; https://doi.org/10.3390/s24103230 (registering DOI) - 19 May 2024
Abstract
Fluorescence induced by the excitation of a fluorophore with plane-polarized light has a different polarization depending on the size of the fluorophore-containing reagent and the rate of its rotation. Based on this effect, many analytical systems have been implemented in which an analyte [...] Read more.
Fluorescence induced by the excitation of a fluorophore with plane-polarized light has a different polarization depending on the size of the fluorophore-containing reagent and the rate of its rotation. Based on this effect, many analytical systems have been implemented in which an analyte contained in a sample and labeled with a fluorophore (usually fluorescein) competes to bind to antibodies. Replacing antibodies in such assays with aptamers, low-cost and stable oligonucleotide receptors, is complicated because binding a fluorophore to them causes a less significant change in the polarization of emissions. This work proposes and characterizes the compounds of the reaction medium that improve analyte binding and reduce the mobility of the aptamer–fluorophore complex, providing a higher analytical signal and a lower detection limit. This study was conducted on aflatoxin B1 (AFB1), a ubiquitous toxicant contaminating foods of plant origins. Eight aptamers specific to AFB1 with the same binding site and different regions stabilizing their structures were compared for affinity, based on which the aptamer with 38 nucleotides in length was selected. The polymers that interact reversibly with oligonucleotides, such as poly-L-lysine and polyethylene glycol, were tested. It was found that they provide the desired reduction in the depolarization of emitted light as well as high concentrations of magnesium cations. In the selected optimal medium, AFB1 detection reached a limit of 1 ng/mL, which was 12 times lower than in the tris buffer commonly used for anti-AFB1 aptamers. The assay time was 30 min. This method is suitable for controlling almond samples according to the maximum permissible levels of their contamination by AFB1. The proposed approach could be applied to improve other aptamer-based analytical systems. Full article
(This article belongs to the Special Issue Fluorescence Sensors for Biological and Medical Applications)
22 pages, 8339 KiB  
Article
Micro-Grinding Parameter Control of Hard and Brittle Materials Based on Kinematic Analysis of Material Removal
by Hisham Manea, Hong Lu, Qi Liu, Junbiao Xiao and Kefan Yang
Mathematics 2024, 12(10), 1589; https://doi.org/10.3390/math12101589 (registering DOI) - 19 May 2024
Abstract
This article explores the intricacies of micro-grinding parameter control for hard and brittle materials, with a specific focus on Zirconia ceramics (ZrO2) and Optical Glass (BK7). Given the increasing demand and application of these materials in various high-precision industries, this study [...] Read more.
This article explores the intricacies of micro-grinding parameter control for hard and brittle materials, with a specific focus on Zirconia ceramics (ZrO2) and Optical Glass (BK7). Given the increasing demand and application of these materials in various high-precision industries, this study aims to provide a comprehensive kinematic analysis of material removal during the micro-grinding process. According to the grinding parameters selected to be analyzed in this study, the ac-max values are between (9.55 nm ~ 67.58 nm). Theoretical modeling of the grinding force considering the brittle and ductile removal phase, frictional effects, the possibility of grit to cut materials, and grinding conditions is very important in order to control and optimize the surface grinding process. This research introduces novel models for predicting and optimizing micro-grinding forces effectively. The primary objective is to establish a micro-grinding force model that facilitates the easy manipulation of micro-grinding parameters, thereby optimizing the machining process for these challenging materials. Through experimental investigations conducted on Zirconia ceramics, the paper evaluates a mathematical model of the grinding force, highlighting its significance in predicting and controlling the forces involved in micro-grinding. The suggested model underwent thorough testing to assess its validity, revealing an accuracy with average variances of 6.616% for the normal force and 5.752% for the tangential force. Additionally, the study delves into the coefficient of friction within the grinding process, suggesting a novel frictional force model. This model is assessed through a series of experiments on Optical Glass BK7, aiming to accurately characterize the frictional forces at play during grinding. The empirical results obtained from both sets of experiments—on Zirconia ceramics and Optical Glass BK7—substantiate the efficacy of the proposed models. These findings confirm the models’ capability to accurately describe the force dynamics in the micro-grinding of hard and brittle materials. The research not only contributes to the theoretical understanding of micro-grinding processes but also offers practical insights for enhancing the efficiency and effectiveness of machining operations involving hard and brittle materials. Full article
Show Figures

Figure 1

25 pages, 14085 KiB  
Article
Superoxide Dismutase Premodulates Oxidative Stress in Plastids for Protection of Tobacco Plants from Cold Damage Ultrastructure Damage
by Ekaterina N. Baranova, Neonila V. Kononenko, Pyotr V. Lapshin, Tatiana L. Nechaeva, Marat R. Khaliluev, Natalia V. Zagoskina, Elena A. Smirnova, Natalya O. Yuorieva, Galina N. Raldugina, Inna A. Chaban, Ludmila V. Kurenina and Alexander A. Gulevich
Int. J. Mol. Sci. 2024, 25(10), 5544; https://doi.org/10.3390/ijms25105544 (registering DOI) - 19 May 2024
Abstract
ROS-dependent induction of oxidative damage can be used as a trigger initiating genetically determined non-specific protection in plant cells and tissues. Plants are potentially able to withstand various specific (toxic, osmotic) factors of abiotic effects, but do not have sufficient or specific sensitivity [...] Read more.
ROS-dependent induction of oxidative damage can be used as a trigger initiating genetically determined non-specific protection in plant cells and tissues. Plants are potentially able to withstand various specific (toxic, osmotic) factors of abiotic effects, but do not have sufficient or specific sensitivity to form an adequate effective response. In this work, we demonstrate one of the possible approaches for successful cold acclimation through the formation of effective protection of photosynthetic structures due to the insertion of the heterologous FeSOD gene into the tobacco genome under the control of the constitutive promoter and equipped with a signal sequence targeting the protein to plastid. The increased enzymatic activity of superoxide dismutase in the plastid compartment of transgenic tobacco plants enables them to tolerate the oxidative factor of environmental stresses scavenging ROS. On the other hand, the cost of such resistance is quite high and, when grown under normal conditions, disturbs the arrangement of the intrachloroplastic subdomains leading to the modification of stromal thylakoids, probably significantly affecting the photosynthesis processes that regulate the efficiency of photosystem II. This is partially compensated for by the fact that, at the same time, under normal conditions, the production of peroxide induces the activation of ROS detoxification enzymes. However, a violation of a number of processes, such as the metabolism of accumulation, and utilization and transportation of sugars and starch, is significantly altered, which leads to a shift in metabolic chains. The expected step for further improvement of the applied technology could be both the use of inducible promoters in the expression cassette, and the addition of other genes encoding for hydrogen peroxide-scavenging enzymes in the genetic construct that are downstream in the metabolic chain. Full article
(This article belongs to the Special Issue Plant Adaptation Mechanism to Stress)
19 pages, 9925 KiB  
Article
Modeling and Simulation of Single Flow Zinc–Nickel Redox Battery Coupled with Multi-Physics Fields
by Chunning Song, Kaixuan Zhang and Nanjun Li
Batteries 2024, 10(5), 166; https://doi.org/10.3390/batteries10050166 (registering DOI) - 19 May 2024
Abstract
Metallic zinc (Zn) presents a compelling alternative to conventional electrochemical energy storage systems due to its environmentally friendly nature, abundant availability, high water compatibility, low toxicity, low electrochemical potential (−0.762 V vs. SHE), and cost-effectiveness. While considerable efforts have been devoted to enhancing [...] Read more.
Metallic zinc (Zn) presents a compelling alternative to conventional electrochemical energy storage systems due to its environmentally friendly nature, abundant availability, high water compatibility, low toxicity, low electrochemical potential (−0.762 V vs. SHE), and cost-effectiveness. While considerable efforts have been devoted to enhancing the physical and chemical properties of zinc-ion battery materials to improve battery efficiency and longevity, research on multi-physics coupled modeling for a deeper understanding of battery performance remains relatively scarce. In this study, we established a comprehensive two-dimensional model for single-flow zinc–nickel redox batteries to investigate electrode reactions, current-potential behaviors, and concentration distributions, leveraging theories such as Nernst–Planck and Butler–Volmer. Additionally, we explored the distribution of the velocity field using the Brinkman theory in porous media and the Navier–Stokes equations in free-flow channels. The validated model, informed by experimental data, not only provides insights into the performance of the battery, but also offers valuable recommendations for advancing single-flow zinc–nickel battery technology. Our findings offer promising avenues for enhancing the design and performance of not only zinc–nickel flow batteries, but also applicable for other flow battery designs. Full article
(This article belongs to the Special Issue Energy Storage of Redox-Flow Batteries)
Show Figures

Figure 1

16 pages, 5204 KiB  
Article
Growth Rings in Nine Tree Species on a Neotropical Island with High Precipitation: Coco Island, Costa Rica
by Róger Moya, Carolina Tenorio and Luis Acosta-Vargas
Forests 2024, 15(5), 885; https://doi.org/10.3390/f15050885 (registering DOI) - 19 May 2024
Abstract
Coco Island, located 530 km off the Pacific coast of Costa Rica, experiences rainfall of over 7000 mm/year. This study aims to explore the distinctiveness of the growth ring boundaries and the dendrochronological potential (DP) of nine tree species found on Coco Island. [...] Read more.
Coco Island, located 530 km off the Pacific coast of Costa Rica, experiences rainfall of over 7000 mm/year. This study aims to explore the distinctiveness of the growth ring boundaries and the dendrochronological potential (DP) of nine tree species found on Coco Island. The distinctiveness was classified into type 1: density variation; type 2: marginal parenchyma; type 3: fiber/parenchyma pattern; type 4: vessel distribution, and type 5: fiber band. Cecropia pittieri and Henriettella fascicularis lacked growth ring boundaries and, therefore, did not present any DP. Growth ring type 1 occurred in Ardisia compressa, Henriettea succosa, Henriettella odorata, and Psychotria cocosensis. Ocotea insularis and Sacoglottis holdridgei exhibited type 5 growth rings, with sufficient distinctiveness. Finally, Eugenia pacifica possessed growth rings of type 3 and type 4, but with limited distinctiveness in the growth ring boundary. In relation to DP, A. compressa, E. pacifica, and P. cocosensis presented low DP; meanwhile, H. succosa, H. odorata, O. insularis, and S. holdridgei demonstrated medium DP. If these species are found in abundance with a diameter exceeding 60 cm, a cross-dating technique like bomb-spike dating is established to confirm the annual growth of the ‘bands’. As these species exhibit some DP, they can be used to establish a chronology spanning 50–130 years, which could be utilized to create climate proxies or derive ecologically and climatically meaningful information. Additionally, the information presented could pave the way for future studies of sites that also have very high rainfall, where trees are presumed to lack annual growth rings. Full article
(This article belongs to the Special Issue Effects of Climate Change on Tree-Ring Growth)
8 pages, 1108 KiB  
Article
Comparison of Current Induced Domain Wall Motion Driven by Spin Transfer Torque and by Spin Orbit Torque in Ferrimagnetic GdFeCo Wires
by Pham Van Thach, Satoshi Sumi, Kenji Tanabe and Hiroyuki Awano
Magnetochemistry 2024, 10(5), 36; https://doi.org/10.3390/magnetochemistry10050036 (registering DOI) - 19 May 2024
Abstract
Current-induced domain wall motion (CIDWM) in magnetic wires can be driven by spin transfer torque (STT) originating from transferring angular momentums of spin-polarized conducting electrons to the magnetic DW and can be driven by spin orbit torque (SOT) originating from the spin Hall [...] Read more.
Current-induced domain wall motion (CIDWM) in magnetic wires can be driven by spin transfer torque (STT) originating from transferring angular momentums of spin-polarized conducting electrons to the magnetic DW and can be driven by spin orbit torque (SOT) originating from the spin Hall effect (SHE) in a heavy metal layer and Dzyaloshinsky Moriya (DMI) generated at an interface between a heavy metal layer and a magnetic layer. In this work, we carried out a comparative study of CIDWM driven by STT and by SOT in ferrimagnetic GdFeCo wires with magnetic perpendicular anisotropy based on structures of SiN (10 nm)/GdFeCo (8 nm)/SiN (10 nm) and Pt (5 nm)/GdFeCo (8 nm)/SiN (10 nm). We found that CIDWM driven by SOT exhibited a much lower critical current density (JC), and much higher DW mobility (µDW). Our work might be useful for the realization and the development of low-power and high-speed memory devices. Full article
(This article belongs to the Special Issue Advances in Functional Materials with Tunable Magnetic Properties)
9 pages, 345 KiB  
Article
Risk Characterization of Firms with ESG Attributes Using a Supervised Machine Learning Method
by Prodosh Eugene Simlai
J. Risk Financial Manag. 2024, 17(5), 211; https://doi.org/10.3390/jrfm17050211 (registering DOI) - 19 May 2024
Abstract
We examine the risk–return tradeoff of a portfolio of firms that have tangible environmental, social, and governance (ESG) attributes. We introduce a new type of penalized regression using the Mahalanobis distance-based method and show its usefulness using our sample of ESG firms. Our [...] Read more.
We examine the risk–return tradeoff of a portfolio of firms that have tangible environmental, social, and governance (ESG) attributes. We introduce a new type of penalized regression using the Mahalanobis distance-based method and show its usefulness using our sample of ESG firms. Our results show that ESG companies are exposed to financial state variables that capture the changes in investment opportunities. However, we find that there is no economically significant difference between the risk-adjusted returns of various ESG-rating-based portfolios and that the risk associated with a poor ESG rating portfolio is not significantly different than that of a good ESG rating portfolio. Although investors require return compensation for holding ESG stocks, the fact that the risk of a poor ESG rating portfolio is comparable to that of a good ESG rating portfolio suggests risk dimensions that go beyond ESG attributes. We further show that the new covariance-adjusted penalized regression improves the out-of-sample cross-sectional predictions of the ESG portfolio's expected returns. Overall, our approach is pragmatic and based on the ease of an empirical appeal. Full article
(This article belongs to the Special Issue Financial Valuation and Econometrics)
30 pages, 4149 KiB  
Article
Camera-Based Crime Behavior Detection and Classification
by Jerry Gao, Jingwen Shi, Priyanka Balla, Akshata Sheshgiri, Bocheng Zhang, Hailong Yu and Yunyun Yang
Smart Cities 2024, 7(3), 1169-1198; https://doi.org/10.3390/smartcities7030050 (registering DOI) - 19 May 2024
Abstract
Increasing numbers of public and private locations now have surveillance cameras installed to make those areas more secure. Even though many organizations still hire someone to monitor the cameras, the person hired is more likely to miss some unexpected events in the video [...] Read more.
Increasing numbers of public and private locations now have surveillance cameras installed to make those areas more secure. Even though many organizations still hire someone to monitor the cameras, the person hired is more likely to miss some unexpected events in the video feeds because of human error. Several researchers have worked on surveillance data and have presented a number of approaches for automatically detecting aberrant events. To keep track of all the video data that accumulate, a supervisor is often required. To analyze the video data automatically, we recommend using neural networks to identify the crimes happening in the real world. Through our approach, it will be easier for police agencies to discover and assess criminal activity more quickly using our method, which will reduce the burden on their staff. In this paper, we aim to provide anomaly detection using surveillance videos as input specifically for the crimes of arson, burglary, stealing, and vandalism. It will provide an efficient and adaptable crime-detection system if integrated across the smart city infrastructure. In our project, we trained multiple accurate deep learning models for object detection and crime classification for arson, burglary and vandalism. For arson, the videos were trained using YOLOv5. Similarly for burglary and vandalism, we trained using YOLOv7 and YOLOv6, respectively. When the models were compared, YOLOv7 performed better with the highest mAP of 87. In this, we could not compare the model’s performance based on crime type because all the datasets for each crime type varied. So, for arson YOLOv5 performed well with 80% mAP and for vandalism, YOLOv6 performed well with 86% mAP. This paper designed an automatic identification of crime types based on camera or surveillance video in the absence of a monitoring person, and alerts registered users about crimes such as arson, burglary, and vandalism through an SMS service. To detect the object of the crime in the video, we trained five different machine learning models: Improved YOLOv5 for arson, Faster RCNN and YOLOv7 for burglary, and SSD MobileNet and YOLOv6 for vandalism. Other than improved models,we innovated by building ensemble models of all three crime types. The main aim of the project is to provide security to the society without human involvement and make affordable surveillance cameras to detect and classify crimes. In addition, we implemented the Web system design using the built package in Python, which is Gradio. This helps the registered user of the Twilio communication tool to receive alert messages when any suspicious activity happens around their communities. Full article
18 pages, 348 KiB  
Article
Driving Economic Growth through Transportation Infrastructure: An In-Depth Spatial Econometric Analysis
by Jianwei Shi, Tongyuan Bai, Zhihong Zhao and Huachun Tan
Sustainability 2024, 16(10), 4283; https://doi.org/10.3390/su16104283 (registering DOI) - 19 May 2024
Abstract
This research investigates the crucial role of transportation infrastructure in influencing economic activity, thus employing advanced econometric methods including Moran’s I index, LM, Hausman, and LR tests to ensure analytical accuracy and select the appropriate spatial model. Our findings reveal that freight volumes [...] Read more.
This research investigates the crucial role of transportation infrastructure in influencing economic activity, thus employing advanced econometric methods including Moran’s I index, LM, Hausman, and LR tests to ensure analytical accuracy and select the appropriate spatial model. Our findings reveal that freight volumes across road, waterway, and civil aviation significantly enhance economic activity by bolstering domestic trade, industrial production, and supply chains. Conversely, the impact of passenger turnover is comparatively minor, although it still contributes to labor mobility and urban accessibility. This study highlights the need for strategic investment in transportation infrastructure and efficient public transport systems to foster economic growth and sustainable development. We recommend that policymakers focus on optimizing transportation networks and integrating intelligent transport technologies to boost economic competitiveness and societal well-being. This analysis not only sheds light on the direct economic impacts of transportation but also underscores the broader social implications, thus advocating for a holistic approach to transportation planning and policymaking. Full article
20 pages, 2983 KiB  
Article
Three-Dimensional Bioprinting of GelMA Hydrogels with Culture Medium: Balancing Printability, Rheology and Cell Viability for Tissue Regeneration
by Laura Mendoza-Cerezo, Jesús M. Rodríguez-Rego, Antonio Macías-García, Antuca Callejas-Marín, Luís Sánchez-Guardado and Alfonso C. Marcos-Romero
Polymers 2024, 16(10), 1437; https://doi.org/10.3390/polym16101437 (registering DOI) - 19 May 2024
Abstract
Three-dimensional extrusion bioprinting technology aims to become a fundamental tool for tissue regeneration using cell-loaded hydrogels. These biomaterials must have highly specific mechanical and biological properties that allow them to generate biosimilar structures by successive layering of material while maintaining cell viability. The [...] Read more.
Three-dimensional extrusion bioprinting technology aims to become a fundamental tool for tissue regeneration using cell-loaded hydrogels. These biomaterials must have highly specific mechanical and biological properties that allow them to generate biosimilar structures by successive layering of material while maintaining cell viability. The rheological properties of hydrogels used as bioinks are critical to their printability. Correct printability of hydrogels allows the replication of biomimetic structures, which are of great use in medicine, tissue engineering and other fields of study that require the three-dimensional replication of different tissues. When bioprinting cell-loaded hydrogels, a small amount of culture medium can be added to ensure adequate survival, which can modify the rheological properties of the hydrogels. GelMA is a hydrogel used in bioprinting, with very interesting properties and rheological parameters that have been studied and defined for its basic formulation. However, the changes that occur in its rheological parameters and therefore in its printability, when it is mixed with the culture medium necessary to house the cells inside, are unknown. Therefore, in this work, a comparative study of GelMA 100% and GelMA in the proportions 3:1 (GelMA 75%) and 1:1 (GelMA 50%) with culture medium was carried out to determine the printability of the gel (using a device of our own invention), its main rheological parameters and its toxicity after the addition of the medium and to observe whether significant differences in cell viability occur. This raises the possibility of its use in regenerative medicine using a 3D extrusion bioprinter. Full article
(This article belongs to the Special Issue 3D and 4D Printing of Polymers: Modeling and Experimental Approaches)
Show Figures

Graphical abstract

15 pages, 4227 KiB  
Article
Transcriptome Analysis Reveals Candidate Genes for Light Regulation of Elsinochrome Biosynthesis in Elsinoë arachidis
by Dan Liu, Jingzi Piao, Yang Li, Haiwen Guan, Jingwen Hao and Rujun Zhou
Microorganisms 2024, 12(5), 1027; https://doi.org/10.3390/microorganisms12051027 (registering DOI) - 19 May 2024
Abstract
Light regulation is critical in fungal growth, development, morphogenesis, secondary metabolism, and the biological clock. The fungus Elsinoë arachidis is known to produce the mycotoxin Elsinochrome (ESC), a key factor contributing to its pathogenicity, under light conditions. Although previous studies have predominantly focused [...] Read more.
Light regulation is critical in fungal growth, development, morphogenesis, secondary metabolism, and the biological clock. The fungus Elsinoë arachidis is known to produce the mycotoxin Elsinochrome (ESC), a key factor contributing to its pathogenicity, under light conditions. Although previous studies have predominantly focused on the light-induced production of ESC and its biosynthetic pathways, the detailed mechanisms underlying this process remain largely unexplored. This study explores the influence of light on ESC production and gene expression in E. arachidis. Under white light exposure for 28 days, the ESC yield was observed to reach 33.22 nmol/plug. Through transcriptome analysis, 5925 genes were identified as differentially expressed between dark and white light conditions, highlighting the significant impact of light on gene expression. Bioinformatics identified specific light-regulated genes, including eight photoreceptor genes, five global regulatory factors, and a cluster of 12 genes directly involved in the ESC biosynthesis, with expression trends confirmed by RT-qPCR. In conclusion, the study reveals the substantial alteration in gene expression associated with ESC biosynthesis under white light and identifies potential candidates for in-depth functional analysis. These findings advance understanding of ESC biosynthesis regulation and suggest new strategies for fungal pathogenicity control. Full article
(This article belongs to the Section Microbiomes)

Open Access Journals

Browse by Indexing Browse by Subject Selected Journals
Back to TopTop