The 2023 MDPI Annual Report has
been released!
 
21 pages, 841 KiB  
Article
A Hierarchical Axiomatic Evaluation of Additive Manufacturing Equipment and the 3D Printing Process Based on Sustainability and Human Factors
by Ismael Mendoza-Muñoz, Mildrend Ivett Montoya-Reyes, Aidé Aracely Maldonado-Macías, Gabriela Jacobo-Galicia and Olivia Yessenia Vargas-Bernal
Processes 2024, 12(6), 1083; https://doi.org/10.3390/pr12061083 (registering DOI) - 25 May 2024
Abstract
As interest in additive manufacturing (AM) continues to increase, it has become more important to have a robust method to help potential users select the AM process that best suits their technological needs while providing the greatest potential benefits in terms of sustainability [...] Read more.
As interest in additive manufacturing (AM) continues to increase, it has become more important to have a robust method to help potential users select the AM process that best suits their technological needs while providing the greatest potential benefits in terms of sustainability and its effect on people. This paper presents the development of a framework for selecting the best AM process for a given application by considering both sustainability and human factors through the combination of axiomatic design and the analytic hierarchy process. Thirty-one participants with varying levels of expertise (novice and advanced users) were involved in the study, considering the frequency of 3D printer usage (novice users: never, rarely; expert users: sometimes, almost always, always) for prototyping parts. They employed fused deposition modeling (FDM) and stereolithography (SLA) (both 3D desktop printers) and collected data on five evaluation criteria. The participation of experts helped establish a novel methodology, with material cost deemed most important (49.8%), followed by cycle time (28%), energy consumption (11.7%), error rate (6.6%), and equipment noise (3.9%). The results showed that FDM was the optimal equipment option for advanced users. By examining the information content of the other options, it was found that FDM demanded less information than SLA, regardless of the user’s level of expertise. The proposed method is appropriate to assess the sustainability aspect of FDM and SLA; however, it can be further improved by adding indicators such as environmental impact, recyclability, and ergonomic and occupational health factors. Full article
14 pages, 3253 KiB  
Article
High-Performance Fiber Ring Laser Based on Polarization Space Parity-Time Symmetry Breaking
by Fengling Zhang, Zhengmao Wu, Xin Tong and Guangqiong Xia
Photonics 2024, 11(6), 501; https://doi.org/10.3390/photonics11060501 (registering DOI) - 25 May 2024
Abstract
This work proposes and experimentally demonstrates a high-performance polarization space parity-time (PT) symmetric fiber ring laser to achieve a low-noise, narrow-linewidth, and highly stable single-longitudinal-mode output. The gain/loss and coupling coefficients are regulated by adjusting a polarization controller (PC) and the pumping current [...] Read more.
This work proposes and experimentally demonstrates a high-performance polarization space parity-time (PT) symmetric fiber ring laser to achieve a low-noise, narrow-linewidth, and highly stable single-longitudinal-mode output. The gain/loss and coupling coefficients are regulated by adjusting a polarization controller (PC) and the pumping current of an erbium-doped fiber amplifier (EDFA) within the ring cavity. The results show that the single longitudinal mode oscillation of the laser can be implemented by PT symmetry breaking. The frequency noise spectral density and the linewidth characteristics of the laser are evaluated by the short-delay self-heterodyne method. The results reveal that excellent low-frequency noise (181 Hz2/Hz at a 10 kHz offset frequency) and narrow fundamental linewidth (68 Hz) can be achieved. Additionally, the laser exhibits outstanding stability with only 0.64 pm wavelength drift over 30 min. By tuning an optical tunable filter (OTF), the wavelength tunable range of the laser can cover the entire C-band. Furthermore, the impacts of different fiber length on the frequency noise spectral density and the filter bandwidth on stability are analyzed, offering guidance for component selection in such laser systems. Full article
(This article belongs to the Special Issue Advanced Lasers and Their Applications II)
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11 pages, 6100 KiB  
Article
Non-Equilibrium Long-Wave Infrared HgCdTe Photodiodes: How the Exclusion and Extraction Junctions Work Separately
by Małgorzata Kopytko, Kinga Majkowycz, Jan Sobieski, Tetiana Manyk and Waldemar Gawron
Materials 2024, 17(11), 2551; https://doi.org/10.3390/ma17112551 (registering DOI) - 25 May 2024
Abstract
The cooling requirement for long-wave infrared detectors still creates significant limitations to their functionality. The phenomenon of minority-carrier exclusion and extraction in narrow-gap semiconductors has been intensively studied for over three decades and used to increase the operating temperatures of devices. Decreasing free [...] Read more.
The cooling requirement for long-wave infrared detectors still creates significant limitations to their functionality. The phenomenon of minority-carrier exclusion and extraction in narrow-gap semiconductors has been intensively studied for over three decades and used to increase the operating temperatures of devices. Decreasing free carrier concentrations below equilibrium values by a stationary non-equilibrium depletion of the device absorber leads to a suppression of Auger generation. In this paper, we focus on analyzing exclusion and extraction effects separately, based on experimental and theoretical results for a HgCdTe photodiode. To carry out an experiment, the n+-P+-π-N+ heterostructure was grown by metal organic chemical vapor deposition on CdTe-buffered GaAs substrate. In order to separate the extraction and exclusive junctions, three different devices were evaluated: (1) a detector etched through the entire n+-P+-π-N+ heterostructure, (2) a detector made of the P+-π photoconductive junction and (3) a detector made of the π-N+ photodiode junction. For each device, the dark current density–voltage characteristics were measured at a high-temperature range, from 195 K to 300 K. Next, the carrier concentration distribution across the entire heterostructure and individual junctions was calculated using the APSYS simulation program. It was shown that when the n+-P+-π-N+ photodiode is reverse biased, the electron concentration in the π absorber drops below its thermal equilibrium value, due to the exclusion effect at the P+-π junction and the extraction effect at the π-N+ junction. To maintain the charge neutrality, the hole concentration is also reduced below the equilibrium value and reaches the absorber doping level (NA), leading to the Auger generation rate’s reduction by a factor of 2ni/NA, where ni is the intrinsic carrier concentration. Our experiment conducted for three separate detectors showed that the exclusion P+-π photoconductive junction has the most significant effect on the Auger suppression—the majority of the hole concentration drops to the doping level not only at the P+-π interface but also deep inside the π absorber. Full article
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12 pages, 857 KiB  
Review
Seed-Coat Pigmentation Plays a Crucial Role in Partner Selection and N2 Fixation in Legume-Root–Microbe Associations in African Soils
by Sanjay K. Jaiswal and Felix D. Dakora
Plants 2024, 13(11), 1464; https://doi.org/10.3390/plants13111464 (registering DOI) - 25 May 2024
Abstract
Legume–rhizobia symbiosis is the most important plant–microbe interaction in sustainable agriculture due to its ability to provide much needed N in cropping systems. This interaction is mediated by the mutual recognition of signaling molecules from the two partners, namely legumes and rhizobia. In [...] Read more.
Legume–rhizobia symbiosis is the most important plant–microbe interaction in sustainable agriculture due to its ability to provide much needed N in cropping systems. This interaction is mediated by the mutual recognition of signaling molecules from the two partners, namely legumes and rhizobia. In legumes, these molecules are in the form of flavonoids and anthocyanins, which are responsible for the pigmentation of plant organs, such as seeds, flowers, fruits, and even leaves. Seed-coat pigmentation in legumes is a dominant factor influencing gene expression relating to N2 fixation and may be responsible for the different N2-fixing abilities observed among legume genotypes under field conditions in African soils. Common bean, cowpea, Kersting’s groundnut, and Bambara groundnut landraces with black seed-coat color are reported to release higher concentrations of nod-gene-inducing flavonoids and anthocyanins compared with the Red and Cream landraces. Black seed-coat pigmentation is considered a biomarker for enhanced nodulation and N2 fixation in legumes. Cowpea, Bambara groundnut, and Kersting’s bean with differing seed-coat colors are known to attract different soil rhizobia based on PCR-RFLP analysis of bacterial DNA. Even when seeds of the same legume with diverse seed-coat colors were planted together in one hole, the nodulating bradyrhizobia clustered differently in the PCR-RFLP dendrogram. Kersting’s groundnut, Bambara groundnut, and cowpea with differing seed-coat colors were selectively nodulated by different bradyrhizobial species. The 16S rRNA amplicon sequencing also found significant selective influences of seed-coat pigmentation on microbial community structure in the rhizosphere of five Kersting’s groundnut landraces. Seed-coat color therefore plays a dominant role in the selection of the bacterial partner in the legume–rhizobia symbiosis. Full article
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26 pages, 1873 KiB  
Review
A Review of Forest Ecosystem Services and Their Spatial Value Characteristics
by Carl Nolander and Robert Lundmark
Forests 2024, 15(6), 919; https://doi.org/10.3390/f15060919 (registering DOI) - 25 May 2024
Abstract
Forests provide a variety of resources and benefits, but only a few, such as timber, are traded on the markets. Ecosystem service valuation is a method for quantifying the non-market benefits of forests to understand the full costs of forest management. This review [...] Read more.
Forests provide a variety of resources and benefits, but only a few, such as timber, are traded on the markets. Ecosystem service valuation is a method for quantifying the non-market benefits of forests to understand the full costs of forest management. This review examines the forest ecosystem service valuations over the past 20 years, with a particular focus on their spatial modeling. The literature review method is designed to provide a systematic, explicit, and reproducible outcome concerning the valuations of forest ecosystem services and the contextual setting of these valuations. The findings suggest that there is a huge variation in the values reported for similar ecosystem services but that carbon sequestration, recreation in forests, and hydrological services, such as watershed protection and flood prevention, are the ecosystem services that are consistently valued highly in the reviewed studies. In the last ten years, studies have more frequently modeled ecosystem services in spatial terms. Full article
(This article belongs to the Special Issue Economic Valuation of Forest Resources)
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19 pages, 481 KiB  
Review
The Role of Oxytocin in Polycystic Ovary Syndrome: A Systematic Review
by Nicoletta Cera, Joana Pinto and Duarte Pignatelli
Curr. Issues Mol. Biol. 2024, 46(6), 5223-5241; https://doi.org/10.3390/cimb46060313 (registering DOI) - 25 May 2024
Abstract
Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder that affects women of reproductive age, representing the primary cause of anovulatory infertility. The nonapeptide oxytocin (OT) plays an important role in cognitive, emotional, and reproductive functions in human beings. Oxytocin receptors are [...] Read more.
Polycystic Ovary Syndrome (PCOS) is the most common endocrine disorder that affects women of reproductive age, representing the primary cause of anovulatory infertility. The nonapeptide oxytocin (OT) plays an important role in cognitive, emotional, and reproductive functions in human beings. Oxytocin receptors are expressed in several body parts, including the ovaries. Despite this, the possible role played by oxytocin in symptoms of PCOS is not clear. The present systematic review aimed at understanding the presence of possible oxytocin level alterations in PCOS, the connection between alterations of OT levels and the symptoms of PCOS, and the effect of oxytocin administration in PCOS. After a systematic search in the principal databases, eight studies, five human and three animal, were included. Four human studies and one animal study highlighted the role played by oxytocin in fertility issues related to PCOS. Three human and two animal studies investigated the role of body weight and OT levels. Studies that analyzed oxytocin basal levels in women agreed that PCOS is associated with a reduction in the serum level of oxytocin. Two human studies and one animal study agreed about lower levels of oxytocin, confirming a possible implication of the dysfunction of OT in the pathogenesis of PCOS. Full article
(This article belongs to the Special Issue Current Advances in Oxytocin Research)
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22 pages, 3018 KiB  
Article
Different Effects of Irrigation Water Salinity and Leaching Fractions on Pepper (Capsicum annuum L.) Cultivation in Soilless Culture
by Hatice Gürgülü and Mehmet Ali Ul
Agriculture 2024, 14(6), 827; https://doi.org/10.3390/agriculture14060827 (registering DOI) - 25 May 2024
Abstract
Pepper (Capsicum annuum L.) is one of the most important vegetables cultivated under greenhouse conditions in Turkey. Salinity problems are experienced in both the soil and irrigation water in agricultural areas. For this reason, soilless cultivation in greenhouses is increasing and important, [...] Read more.
Pepper (Capsicum annuum L.) is one of the most important vegetables cultivated under greenhouse conditions in Turkey. Salinity problems are experienced in both the soil and irrigation water in agricultural areas. For this reason, soilless cultivation in greenhouses is increasing and important, meaning that salinity control must be conducted more effectively. The increase in soilless agriculture practices and salinity problems should be investigated and studies should be carried out to propose solutions to the problems experienced. In this study, the effects of different salinity levels and leaching fractions on the plant growth, yield, quality and water consumption of pepper grown in soilless cultures were determined. The experiment was carried out over four growing periods across two years. The adopted experimental design was a randomized split-plot design with three replications. Pepper plants were grown in a perlite and cocopeat mixture in 144 pots. The volume of the pots was 8 L and the pots were filled with a mixture of 4 L of perlite and 4 L of cocopeat. The plants were fed with a complete nutrient solution and their EC levels were used as the control treatment (S1: the EC value of the control was 1.4–1.5 dS m−1). The electrical conductivities of the solution in the other three treatments were increased to 2 (S2), 4 (S3) and 6 (S4) dS m−1 above the control by adding NaCl. We attempted to achieve two different leaching fractions (LR: leaching ratio) by means of weekly measurements, with 15–20% (LR1) or 35–40% (LR2) being applied at each salinity level. According to our results, there was no significant difference between the leaching fractions with respect to yield in any of the four growing seasons, but the yield decreased with the increase in salinity. The difference between the salinity level treatments and their interactions between the subjects was generally significant for the production periods. Full article
(This article belongs to the Special Issue Effects of Salt Stress on Crop Production)
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18 pages, 3253 KiB  
Article
Concanavalin A Delivers a Photoactive Protein to the Bacterial Wall
by Andrea Mussini, Pietro Delcanale, Melissa Berni, Stefano Pongolini, Mireia Jordà-Redondo, Montserrat Agut, Peter J. Steinbach, Santi Nonell, Stefania Abbruzzetti and Cristiano Viappiani
Int. J. Mol. Sci. 2024, 25(11), 5751; https://doi.org/10.3390/ijms25115751 (registering DOI) - 25 May 2024
Abstract
Modular supramolecular complexes, where different proteins are assembled to gather targeting capability and photofunctional properties within the same structures, are of special interest for bacterial photodynamic inactivation, given their inherent biocompatibility and flexibility. We have recently proposed one such structure, exploiting the tetrameric [...] Read more.
Modular supramolecular complexes, where different proteins are assembled to gather targeting capability and photofunctional properties within the same structures, are of special interest for bacterial photodynamic inactivation, given their inherent biocompatibility and flexibility. We have recently proposed one such structure, exploiting the tetrameric bacterial protein streptavidin as the main building block, to target S. aureus protein A. To expand the palette of targets, we have linked biotinylated Concanavalin A, a sugar-binding protein, to a methylene blue-labelled streptavidin. By applying a combination of spectroscopy and microscopy, we demonstrate the binding of Concanavalin A to the walls of Gram-positive S. aureus and Gram-negative E. coli. Photoinactivation is observed for both bacterial strains in the low micromolar range, although the moderate affinity for the molecular targets and the low singlet oxygen yields limit the overall efficiency. Finally, we apply a maximum entropy method to the analysis of autocorrelation traces, which proves particularly useful when interpreting signals measured for diffusing systems heterogeneous in size, such as fluorescent species bound to bacteria. Full article
(This article belongs to the Special Issue New Molecular Insights into Antimicrobial Photo-Treatments)
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13 pages, 2529 KiB  
Article
Research on the Coupling Effect of NBTI and TID for FDSOI pMOSFETs
by Hao Wei, Hongxia Liu, Shulong Wang, Shupeng Chen, Chenyv Yin, Yaolin Chen and Tianzhi Gao
Micromachines 2024, 15(6), 702; https://doi.org/10.3390/mi15060702 (registering DOI) - 25 May 2024
Abstract
The coupling effect of negative bias temperature instability (NBTI) and total ionizing dose (TID) was investigated by simulation based on the fully depleted silicon on insulator (FDSOI) PMOS. After simulating the situation of irradiation after NBT stress, it was found that the NBTI [...] Read more.
The coupling effect of negative bias temperature instability (NBTI) and total ionizing dose (TID) was investigated by simulation based on the fully depleted silicon on insulator (FDSOI) PMOS. After simulating the situation of irradiation after NBT stress, it was found that the NBTI effect weakens the threshold degradation of FDSOI PMOS under irradiation. Afterward, NBT stress was decomposed into high gate voltage stress and high-temperature stress, which was applied to the device simultaneously with irradiation. The devices under high gate voltage exhibited more severe threshold voltage degradation after irradiation compared to those under low gate voltage. Devices at high temperatures also exhibit more severe threshold degradation after irradiation compared to devices under low temperatures. Finally, the simultaneous effect of high gate voltage, high temperature, and irradiation on the device was investigated, which fully demonstrated the impact of the NBT stress on the TID effect, resulting in far more severe threshold voltage degradation. Full article
(This article belongs to the Section D1: Semiconductor Devices)
24 pages, 450 KiB  
Article
Navigating Uncharted Waters: The Transformation of the Bank of Korea’s Monetary Policy in Response to Global Economic Uncertainty
by Yugang He and Zhuoqi Teng
Mathematics 2024, 12(11), 1657; https://doi.org/10.3390/math12111657 (registering DOI) - 25 May 2024
Abstract
The evolving global economic landscape necessitates adaptive monetary policies, especially for economies like South Korea that are deeply integrated with global markets. This research explores the strategic recalibrations of the Bank of Korea’s monetary policy amid fluctuations in global economic uncertainty. Utilizing a [...] Read more.
The evolving global economic landscape necessitates adaptive monetary policies, especially for economies like South Korea that are deeply integrated with global markets. This research explores the strategic recalibrations of the Bank of Korea’s monetary policy amid fluctuations in global economic uncertainty. Utilizing a sophisticated microeconomic theoretical framework, this study employs Bayesian estimation techniques and impulse response analysis to dissect the dynamic effects of these global shocks on South Korea’s macroeconomic stability and policy direction. Our findings reveal that the Bank of Korea has adeptly navigated through turbulent economic conditions induced by external shocks through well-coordinated policy adaptations. These adaptations, which include both traditional and innovative monetary tools, have been crucial in stabilizing the financial environment and promoting economic growth. By detailing the tailored application of the Taylor rule within the Korean context and strategic foreign exchange interventions by the central bank, this study contributes significantly to the broader discourse on the efficacy of monetary policy in open economies and offers insights on integrating advanced analytical methods into economic policy analysis. Full article
20 pages, 1819 KiB  
Article
Environmental and Economic Performance of Greenhouse Cropping in the Mediterranean Basin: Lessons Learnt from a Cross-Country Comparison
by Sara Sturiale, Oriana Gava, Marisa Gallardo, Dolores Buendía Guerrero, Dursun Buyuktas, Gulcin Ece Aslan, Asma Laarif, Thameur Bouslama, Alejandra Navarro, Luca Incrocci and Fabio Bartolini
Sustainability 2024, 16(11), 4491; https://doi.org/10.3390/su16114491 (registering DOI) - 25 May 2024
Abstract
In the Mediterranean region, the expansion of greenhouse horticulture has enabled the year-round supply of fresh vegetables. Compared to open field horticulture, this farming method can generate higher returns for farmers. However, it is often associated with significant environmental pressures. This research aims [...] Read more.
In the Mediterranean region, the expansion of greenhouse horticulture has enabled the year-round supply of fresh vegetables. Compared to open field horticulture, this farming method can generate higher returns for farmers. However, it is often associated with significant environmental pressures. This research aims to pinpoint important opportunities for improvement of the environmental and economic performance of greenhouse farming in the Mediterranean region by showing the life cycle’s environmental and economic impacts and by highlighting life cycle hotspots. This is achieved through the combined application of life cycle assessment and life cycle costing to four case studies (commercial greenhouses) spanning the Mediterranean Basin (Italy, Spain, Tunisia, and Turkey). The case study findings highlight the following environmental hotspots and related impacts: (i) fertigation management can generate up to 11,283 m3/ha/year of water use impact; (ii) fertilizer leaching can generate up to 27 kg of N eq marine eutrophication impact; and (iii) crop protection treatments can generate up to 130,037 kg 1,4-DCB of terrestrial ecotoxicity impact. The large use of plastic materials (greenhouse and fertigation infrastructures) is an additional critical aspect due to manufacturing and disposal, contributing to eutrophication impact categories. Economic hotspots are related to greenhouse management (up to 35% total costs of production) and hired labor (up to 40% total costs of production). The lessons learnt from these case studies offer valuable insights into the sustainability challenges of greenhouse horticulture across the Mediterranean region. The hotspot analysis points to the need for targeted interventions to mitigate the most critical impacts while ensuring economic viability. This study enriches scientific understanding by examining different production and socioeconomic contexts, offering crucial insights for the advancement of sustainable practices in greenhouse agriculture such as the use of decision support systems to optimize input use. Full article
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17 pages, 5804 KiB  
Article
Genomic Analysis of Brassinosteroid Biosynthesis Gene Family Reveals Its Roles in Cotton Development across Gossypium Species
by Shiyan Cui, Xin Zhou, Guanghui Xiao and Hongjie Feng
Biology 2024, 13(6), 380; https://doi.org/10.3390/biology13060380 (registering DOI) - 25 May 2024
Abstract
Cotton is a globally significant economic crop. Brassinosteroids (BRs) are crucial to cotton development. This study systematically analyzed the BR synthase gene family in four cotton species and identified 60 BR genes: 20 in Gossypium hirsutum (GhBRs), 20 in G. barbadense [...] Read more.
Cotton is a globally significant economic crop. Brassinosteroids (BRs) are crucial to cotton development. This study systematically analyzed the BR synthase gene family in four cotton species and identified 60 BR genes: 20 in Gossypium hirsutum (GhBRs), 20 in G. barbadense (GbBRs), 10 in G. arboreum (GaBRs), and 10 in G. raimondii (GrBRs). The analysis was extended to chromosomal localization, evolutionary relationships, domain features, and cis-regulatory elements in the promoter regions of BR synthase genes. The results showed that the BR synthase genes were evenly distributed across different subgenomes and chromosomes. Bioinformatics analyses revealed high conservation of amino acid sequences, secondary structures, and conserved domains among the subfamily members, which is closely linked to their pivotal roles in the BR biosynthesis pathway. Cis-element distribution analysis of the BR synthase genes further underscored the complexity of BR gene expression regulation, which is influenced by multiple factors, including plant hormones, abiotic stress, and transcription factors. Expression profiling of GhBRs genes in various cotton tissues and developmental stages highlighted the key roles of GhROT3-1 and GhDET2-1 in fiber elongation and initiation, respectively. Protein–protein interactions and transcription factor analyses further elucidated the regulatory mechanisms of GhROT3-1 and GhDET2-1 in cotton growth and development. This study lays a theoretical foundation for understanding the role of the BR signaling pathway in cotton development, facilitating molecular breeding. Full article
(This article belongs to the Section Biochemistry and Molecular Biology)
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10 pages, 2958 KiB  
Article
Bidirectional Optical Neural Networks Based on Free-Space Optics Using Lens Arrays and Spatial Light Modulator
by Young-Gu Ju
Micromachines 2024, 15(6), 701; https://doi.org/10.3390/mi15060701 (registering DOI) - 25 May 2024
Abstract
This paper introduces a novel architecture—bidirectional optical neural network (BONN)—for providing backward connections alongside forward connections in artificial neural networks (ANNs). BONN incorporates laser diodes and photodiodes and exploits the properties of Köhler illumination to establish optical channels for backward directions. Thus, it [...] Read more.
This paper introduces a novel architecture—bidirectional optical neural network (BONN)—for providing backward connections alongside forward connections in artificial neural networks (ANNs). BONN incorporates laser diodes and photodiodes and exploits the properties of Köhler illumination to establish optical channels for backward directions. Thus, it has bidirectional functionality that is crucial for algorithms such as the backpropagation algorithm. BONN has a scaling limit of 96 × 96 for input and output arrays, and a throughput of 8.5 × 1015 MAC/s. While BONN’s throughput may rise with additional layers for continuous input, limitations emerge in the backpropagation algorithm, as its throughput does not scale with layer count. The successful BONN-based implementation of the backpropagation algorithm requires the development of a fast spatial light modulator to accommodate frequent data flow changes. A two-mirror-like BONN and its cascaded extension are alternatives for multilayer emulation, and they help save hardware space and increase the parallel throughput for inference. An investigation into the application of the clustering technique to BONN revealed its potential to help overcome scaling limits and to provide full interconnections for backward directions between doubled input and output ports. BONN’s bidirectional nature holds promise for enhancing supervised learning in ANNs and increasing hardware compactness. Full article
(This article belongs to the Special Issue Design and Manufacture of Micro-Optical Lens)
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18 pages, 1296 KiB  
Article
Classification Strategy for Power Quality Disturbances Based on Variational Mode Decomposition Algorithm and Improved Support Vector Machine
by Le Gao, Jinhao Wang, Min Zhang, Shifeng Zhang, Hanwen Wang and Yang Wang
Processes 2024, 12(6), 1084; https://doi.org/10.3390/pr12061084 (registering DOI) - 25 May 2024
Abstract
With the continuous improvement in production efficiency and quality of life, the requirements of electrical equipment for power quality are also increasing. Accurate detection of various power quality disturbances is an effective measure to improve power quality. However, in practical applications, the dataset [...] Read more.
With the continuous improvement in production efficiency and quality of life, the requirements of electrical equipment for power quality are also increasing. Accurate detection of various power quality disturbances is an effective measure to improve power quality. However, in practical applications, the dataset is often contaminated by noise, and when the dataset is not sufficient, the computational complexity is too high. Similarly, in the recognition process of artificial neural networks, the local optimum often occurs, which ultimately leads to low recognition accuracy for the trained model. Therefore, this article proposes a power quality disturbance classification strategy based on the variational mode decomposition (VMD) and improved support vector machine (SVM) algorithms. Firstly, the VMD algorithm is used for preprocessing disturbance denoising. Next, based on the analysis of typical fault characteristics, a multi-SVM model is used for disturbance classification identification. In order to improve the recognition accuracy, the improved Grey Wolf Optimization (IGWO) algorithm is used to optimize the penalty factor and kernel function parameters of the SVM model. The results of the final case study show that the classification accuracy of the proposed method can reach over 98%, and the recognition accuracy is higher than that of the other models. Full article
(This article belongs to the Section Energy Systems)
21 pages, 777 KiB  
Article
Variable Temporal Length Training for Action Recognition CNNs
by Tan-Kun Li, Kwok-Leung Chan and Tardi Tjahjadi
Sensors 2024, 24(11), 3403; https://doi.org/10.3390/s24113403 (registering DOI) - 25 May 2024
Abstract
Most current deep learning models are suboptimal in terms of the flexibility of their input shape. Usually, computer vision models only work on one fixed shape used during training, otherwise their performance degrades significantly. For video-related tasks, the length of each video (i.e., [...] Read more.
Most current deep learning models are suboptimal in terms of the flexibility of their input shape. Usually, computer vision models only work on one fixed shape used during training, otherwise their performance degrades significantly. For video-related tasks, the length of each video (i.e., number of video frames) can vary widely; therefore, sampling of video frames is employed to ensure that every video has the same temporal length. This training method brings about drawbacks in both the training and testing phases. For instance, a universal temporal length can damage the features in longer videos, preventing the model from flexibly adapting to variable lengths for the purposes of on-demand inference. To address this, we propose a simple yet effective training paradigm for 3D convolutional neural networks (3D-CNN) which enables them to process videos with inputs having variable temporal length, i.e., variable length training (VLT). Compared with the standard video training paradigm, our method introduces three extra operations during training: sampling twice, temporal packing, and subvideo-independent 3D convolution. These operations are efficient and can be integrated into any 3D-CNN. In addition, we introduce a consistency loss to regularize the representation space. After training, the model can successfully process video with varying temporal length without any modification in the inference phase. Our experiments on various popular action recognition datasets demonstrate the superior performance of the proposed method compared to conventional training paradigm and other state-of-the-art training paradigms. Full article
(This article belongs to the Section Sensing and Imaging)
21 pages, 1202 KiB  
Review
Fibroblasts in Pulmonary Hypertension: Roles and Molecular Mechanisms
by Hui Zhang, Min Li, Cheng-Jun Hu and Kurt R. Stenmark
Cells 2024, 13(11), 914; https://doi.org/10.3390/cells13110914 (registering DOI) - 25 May 2024
Abstract
Fibroblasts, among the most prevalent and widely distributed cell types in the human body, play a crucial role in defining tissue structure. They do this by depositing and remodeling extracellular matrixes and organizing functional tissue networks, which are essential for tissue homeostasis and [...] Read more.
Fibroblasts, among the most prevalent and widely distributed cell types in the human body, play a crucial role in defining tissue structure. They do this by depositing and remodeling extracellular matrixes and organizing functional tissue networks, which are essential for tissue homeostasis and various human diseases. Pulmonary hypertension (PH) is a devastating syndrome with high mortality, characterized by remodeling of the pulmonary vasculature and significant cellular and structural changes within the intima, media, and adventitia layers. Most research on PH has focused on alterations in the intima (endothelial cells) and media (smooth muscle cells). However, research over the past decade has provided strong evidence of the critical role played by pulmonary artery adventitial fibroblasts in PH. These fibroblasts exhibit the earliest, most dramatic, and most sustained proliferative, apoptosis-resistant, and inflammatory responses to vascular stress. This review examines the aberrant phenotypes of PH fibroblasts and their role in the pathogenesis of PH, discusses potential molecular signaling pathways underlying these activated phenotypes, and highlights areas of research that merit further study to identify promising targets for the prevention and treatment of PH. Full article
16 pages, 3363 KiB  
Article
Synthesis of Boronate Affinity-Based Oriented Dummy Template-Imprinted Magnetic Nanomaterials for Rapid and Efficient Solid-Phase Extraction of Ellagic Acid from Food
by Daojin Li, Na Tang and Xiping Tian
Molecules 2024, 29(11), 2500; https://doi.org/10.3390/molecules29112500 (registering DOI) - 25 May 2024
Abstract
Ellagic acid (EA) is a natural polyphenol and possesses excellent in vivo bioactivity and antioxidant behaviors, which play an important role in the treatment of oxidative stress-related diseases, such as cancer. Additionally, EA is also known as a skin-whitening ingredient. The content of [...] Read more.
Ellagic acid (EA) is a natural polyphenol and possesses excellent in vivo bioactivity and antioxidant behaviors, which play an important role in the treatment of oxidative stress-related diseases, such as cancer. Additionally, EA is also known as a skin-whitening ingredient. The content of EA would determine its efficacy. Therefore, the accurate analysis of EA content can provide more information for the scientific consumption of EA-rich foods and cosmetics. Nevertheless, the analysis of EA in these samples is challenging due to the low concentration level and the presence of interfering components with high abundance. Molecularly imprinted polymers are highly efficient pretreatment materials in achieving specific recognition of target molecules. However, the traditional template molecule (EA) could not be absolutely removed. Hence, template leakage continues to occur during the sample preparation process, leading to a lack of accuracy in the quantification of EA in actual samples, particularly for trace analytes. In addition, another drawback of EA as an imprinting template is that EA possesses poor solubility and a high price. Gallic acid (GA), called dummy templates, was employed for the synthesis of MIPs as a solution to these challenges. The approach used in this study was boronate affinity-based oriented surface imprinting. The prepared dummy-imprinted nanoparticles exhibited several significant advantages, such as good specificity, high binding affinity ((4.89 ± 0.46) × 10−5 M), high binding capacity (6.56 ± 0.35 mg/g), fast kinetics (6 min), and low binding pH (pH 5.0) toward EA. The reproducibility of the dummy-imprinted nanoparticles was satisfactory. The dummy-imprinted nanoparticles could still be reused even after six adsorption–desorption cycles. In addition, the recoveries of the proposed method for EA at three spiked levels of analysis in strawberry and pineapple were 91.0–106.8% and 93.8–104.0%, respectively, which indicated the successful application to real samples. Full article
(This article belongs to the Section Analytical Chemistry)
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21 pages, 2344 KiB  
Article
Impact of Exclusive Choice Policies on Platform Supply Chains: When Both Same-Side and Cross-Side Network Effects Exist
by Haijun Chen and Qi Xu
J. Theor. Appl. Electron. Commer. Res. 2024, 19(2), 1185-1205; https://doi.org/10.3390/jtaer19020061 (registering DOI) - 25 May 2024
Abstract
This research investigates the effects of “choose-one-over-another” monopolistic strategies on two-sided platforms, analyzing the implications of such practices on network effects and platform economics through the Hotelling model. Our key findings include the following: (1) “Choose-one-over-another” policies enhance positive network effects, increasing multi-homing [...] Read more.
This research investigates the effects of “choose-one-over-another” monopolistic strategies on two-sided platforms, analyzing the implications of such practices on network effects and platform economics through the Hotelling model. Our key findings include the following: (1) “Choose-one-over-another” policies enhance positive network effects, increasing multi-homing on the demand side but reducing overall platform revenue. These policies also intensify negative network effects, leading to higher prices for supply-side users and thereby undermining the welfare of demand-side users. (2) After antitrust interventions, platforms adjust pricing dynamically, increasing for one side and decreasing for the other in response to changes in same-side network effects, which in turn influences multi-homing behaviors and revenue impacts differently before and after the enforcement of such policies. (3) Without exclusive selection mandates, platform pricing strategies tend to lower prices for supply-side users, especially under competitive pressures or weaker positive network effects, potentially increasing platform revenue and overall supply chain welfare under certain conditions. This study highlights the critical role of regulatory oversight in curbing monopolistic platform behaviors to protect user rights and ensure market health, offering strategic guidance for platform management amidst competitive and operational challenges. Full article
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17 pages, 2865 KiB  
Article
Innovative Non-Invasive and Non-Intrusive Precision Thermometry in Stainless-Steel Tanks Using Ultrasound Transducers
by Ahmed Bouzid, Saad Chidami, Tristan Quentin Lailler, Adrián Carrillo García, Tarek Ould-Bachir and Jamal Chaouki
Sensors 2024, 24(11), 3404; https://doi.org/10.3390/s24113404 (registering DOI) - 25 May 2024
Abstract
Measuring temperature inside chemical reactors is crucial to ensuring process control and safety. However, conventional methods face a number of limitations, such as the invasiveness and the restricted dynamic range. This paper presents a novel approach using ultrasound transducers to enable accurate temperature [...] Read more.
Measuring temperature inside chemical reactors is crucial to ensuring process control and safety. However, conventional methods face a number of limitations, such as the invasiveness and the restricted dynamic range. This paper presents a novel approach using ultrasound transducers to enable accurate temperature measurements. Our experiments, conducted within a temperature range of 28.8 to 83.8 °C, reveal a minimal temperature accuracy of 98.6% within the critical zone spanning between 70.5 and 75 °C, and an accuracy of over 99% outside this critical zone. The experiments focused on a homogeneous environment of distilled water within a stainless-steel tank. This approach will be extended in a future research in order to diversify the experimental media and non-uniform environments, while promising broader applications in chemical process monitoring and control. Full article
(This article belongs to the Collection Instrument and Measurement)
18 pages, 8138 KiB  
Article
Experimental Study on Rats with Critical-Size Bone Defects Comparing Effects of Autologous Bone Graft, Equine Bone Substitute Bio-Gen® Alone or in Association with Platelet-Rich Fibrin (PRF)
by Petru Ciobanu, Mihai Danciu, Andrei Pascu, Ioannis Gardikiotis, Norin Forna, Mihnea Theodor Sirbu, Anca-Elena Calistru, Bogdan Puha, Bogdan Veliceasa and Paul-Dan Sirbu
Polymers 2024, 16(11), 1502; https://doi.org/10.3390/polym16111502 (registering DOI) - 25 May 2024
Abstract
Background: A critical-sized bone defect (CsBD) is considered one that will not heal spontaneously and requires reconstruction. This study aims to compare the results of using different bone reconstructive techniques and to study the potential of platelet-rich fibrin (PRF) to enhance the healing [...] Read more.
Background: A critical-sized bone defect (CsBD) is considered one that will not heal spontaneously and requires reconstruction. This study aims to compare the results of using different bone reconstructive techniques and to study the potential of platelet-rich fibrin (PRF) to enhance the healing properties of a bone substitute (BS). Methods: In this experimental study on rats, the treatment of critical-sized bone defects was carried out by analysing four groups: a control group in which the bone defect was left empty; a group treated with Bio-Gen®; another group in which the defect was treated with PRF in combination with Bio-Gen®; and the last that was treated with autologous bone graft (ABG). The defects were evaluated by microcomputed tomography (µCT) and then histomorphometrically. Results: From both the histological and imagistic point of view, the best results were registered in the ABG group, followed by the group treated with Bio-Gen® with PRF, Bio-Gen® group, and control group, with statistically significant differences. Conclusions: A 5 mm defect in the rat radius can be considered critical. ABG showed the best results in treating the bone defect. PRF significantly enhanced the efficacy of Bio-Gen®. Full article
(This article belongs to the Special Issue Polymer-Based Biomaterials for Tissue Engineering Applications)
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21 pages, 421 KiB  
Article
Exploration or Exploitation? Corporate Green Innovation Strategy for Carbon Emission Reduction-Evidence from Pilot Enterprises in China
by Shanshan Liu and Yugang Li
Sustainability 2024, 16(11), 4486; https://doi.org/10.3390/su16114486 (registering DOI) - 25 May 2024
Abstract
Green innovation has become a key strategy for reducing emissions. However, existing research mainly examines this phenomenon through the resource and institutional perspectives, often ignoring the changes in corporate green innovation behavior under industry peer pressure. Therefore, this study draws on the policy [...] Read more.
Green innovation has become a key strategy for reducing emissions. However, existing research mainly examines this phenomenon through the resource and institutional perspectives, often ignoring the changes in corporate green innovation behavior under industry peer pressure. Therefore, this study draws on the policy framework of China’s carbon trading pilot and uses a multi-period difference-in-difference (DID) fixed effects model to explore how carbon trading shapes enterprises’ green innovation strategies. The survey used data from pilot enterprises from 2008 to 2019 and found that carbon trading policies are conducive to green innovation, and both exploratory green innovation and exploitative green innovation have been reflected. It is worth noting that under the influence of peer pressure, this positive effect is more prominent in exploratory green innovation. Furthermore, it was found that firms facing carbon pressure can skillfully find an equilibrium between exploratory green innovation and exploitative green innovation. The research results demonstrate the green innovation strategies and trade-offs of Chinese enterprises facing the impact of carbon trading policies, with the hope that the research conclusions will have certain theoretical reference significance for future corporate green transformation and increased investment in green innovation. Full article
19 pages, 5659 KiB  
Review
Recent Advances in Positive Photoresists: Mechanisms and Fabrication
by Muhammad Hassaan, Umama Saleem, Akash Singh, Abrar Jawad Haque and Kaiying Wang
Materials 2024, 17(11), 2552; https://doi.org/10.3390/ma17112552 (registering DOI) - 25 May 2024
Abstract
Photoresists are fundamental materials in photolithography and are crucial for precise patterning in microelectronic devices, MEMS, and nanostructures. This paper provides an in-depth review of recent advancements in positive photoresist research and development, focusing on discussion regarding the underlying mechanisms governing their behavior, [...] Read more.
Photoresists are fundamental materials in photolithography and are crucial for precise patterning in microelectronic devices, MEMS, and nanostructures. This paper provides an in-depth review of recent advancements in positive photoresist research and development, focusing on discussion regarding the underlying mechanisms governing their behavior, exploring innovative fabrication techniques, and highlighting the advantages of the photoresist classes discussed. The paper begins by discussing the need for the development of new photoresist technologies, highlighting issues associated with adopting extreme ultraviolet photolithography and addressing these challenges through the development of advanced positive-tone resist materials with improved patterning features, resolution, and sensitivity. Subsequently, it discusses the working mechanisms and synthesis methods of different types and subtypes of photoresists, starting from non-chemically amplified, organic, and inorganic–organic hybrid photoresists and progressing to dry film resists, with an emphasis on the upsides of each. The paper concludes by discussing how future research in the field of lithography—prioritizing concerns related to environmental impacts, improved photoresist material and properties, and utilization of advanced quantum technology—can assist with revolutionizing lithography techniques. Full article
26 pages, 3899 KiB  
Article
Metabolomic and Physiological Effects of a Cardiorenal Protective Diet Intervention in African American Adults with Chronic Kidney Disease
by Meera J. Patel, Chiamaka Emerenini, Xuan Wang, Teodoro Bottiglieri and Heather Kitzman
Metabolites 2024, 14(6), 300; https://doi.org/10.3390/metabo14060300 (registering DOI) - 25 May 2024
Abstract
Chronic kidney disease (CKD) impacts 14% of adults in the United States, and African American (AA) individuals are disproportionately affected, with more than 3 times higher risk of kidney failure as compared to White individuals. This study evaluated the effects of base-producing fruit [...] Read more.
Chronic kidney disease (CKD) impacts 14% of adults in the United States, and African American (AA) individuals are disproportionately affected, with more than 3 times higher risk of kidney failure as compared to White individuals. This study evaluated the effects of base-producing fruit and vegetables (FVs) on cardiorenal outcomes in AA persons with CKD and hypertension (HTN) in a low socioeconomic area. The “Cardiorenal Protective Diet” prospective randomized trial evaluated the effects of a 6-week, community-based FV intervention compared to a waitlist control (WL) in 91 AA adults (age = 58.3 ± 10.1 years, 66% female, 48% income ≤ USD 25K). Biometric and metabolomic variables were collected at baseline and 6 weeks post-intervention. The change in health outcomes for both groups was statistically insignificant (p > 0.05), though small reductions in albumin to creatinine ratio, body mass index, total cholesterol, and systolic blood pressure were observed in the FV group. Metabolomic profiling identified key markers (p < 0.05), including C3, C5, 1-Met-His, kynurenine, PC ae 38:5, and choline, indicating kidney function decline in the WL group. Overall, delivering a directed cardiorenal protective diet intervention improved cardiorenal outcomes in AA adults with CKD and HTN. Additionally, metabolomic profiling may serve as a prognostic technique for the early identification of biomarkers as indicators for worsening CKD and increased CVD risk. Full article
(This article belongs to the Special Issue Nutritional Epidemiology and Metabolic Disorders)

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