The 2023 MDPI Annual Report has
been released!
 
12 pages, 1285 KiB  
Communication
The Pulsar Timing Array Signal from Infrared Regions of Scalar-Induced Gravitational Waves
by Qin Fei
Universe 2024, 10(6), 255; https://doi.org/10.3390/universe10060255 - 7 Jun 2024
Abstract
The common-spectrum process, characterized by the Hellings–Downs angular correlation and observed by pulsar timing array collaborations, such as NANOGrav, PPTA, EPTA, and CPTA, can be explained by the scalar-induced gravitational waves (SIGWs). The energy density of SIGWs exhibits universal behavior in the infrared [...] Read more.
The common-spectrum process, characterized by the Hellings–Downs angular correlation and observed by pulsar timing array collaborations, such as NANOGrav, PPTA, EPTA, and CPTA, can be explained by the scalar-induced gravitational waves (SIGWs). The energy density of SIGWs exhibits universal behavior in the infrared regions. Utilizing a broken power law parameterization for the primordial curvature power spectrum, we clarify the PTA signal through the infrared characteristics of the SIGWs, using Bayesian analysis to provide posterior distributions. Bayesian factors emphasize the statistical preference for the SIGW model over explanations involving supermassive black hole binaries. Full article
(This article belongs to the Section Cosmology)
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15 pages, 15884 KiB  
Article
A Data-Driven Motor Optimization Method Based on Support Vector Regression—Multi-Objective, Multivariate, and with a Limited Sample Size
by Guanghao Li, Ruicheng Li, Haobo Hou, Guoyi Zhang and Zhiyong Li
Electronics 2024, 13(12), 2231; https://doi.org/10.3390/electronics13122231 - 7 Jun 2024
Abstract
The increasing demand for sustainable development and energy efficiency underscores the importance of optimizing motors in driving the upgrade of energy structures. This paper studies a data-driven approach for the multi-objective optimization of motors designed for scenarios involving multiple variables, objectives, and limited [...] Read more.
The increasing demand for sustainable development and energy efficiency underscores the importance of optimizing motors in driving the upgrade of energy structures. This paper studies a data-driven approach for the multi-objective optimization of motors designed for scenarios involving multiple variables, objectives, and limited sample sizes and validates its efficacy. Initially, sensitivity analysis is employed to identify potentially influential variables, thus selecting key design parameters. Subsequently, Latin hypercube sampling (LHS) is utilized to select experimental points, ensuring the coverage of the modeled test points across the experimental space to enhance fitting accuracy. Finally, the support vector regression (SVR) algorithm is employed to fit the objective function, in conjunction with multi-objective particle swarm optimization (MOPSO) for solution derivation. The presented method is used to optimize the efficiency, average output torque, and induced electromotive force harmonic distortion rate of a permanent magnet synchronous motor (PMSM). The results show an improvement of approximately 6.80% in average output torque and a significant decrease of about 59.5% in the induced electromotive force harmonic distortion rate, with minimal impact on efficiency. This study offers a pathway for enhancing motor performance, holding practical significance. Full article
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19 pages, 6925 KiB  
Article
Improving Object Detection Accuracy with Self-Training Based on Bi-Directional Pseudo Label Recovery
by Shoaib Sajid, Zafar Aziz, Odilbek Urmonov and HyungWon Kim
Electronics 2024, 13(12), 2230; https://doi.org/10.3390/electronics13122230 - 7 Jun 2024
Abstract
Semi-supervised training methods need reliable pseudo labels for unlabeled data. The current state-of-the-art methods based on pseudo labeling utilize only high-confidence predictions, whereas poor confidence predictions are discarded. This paper presents a novel approach to generate high-quality pseudo labels for unlabeled data. It [...] Read more.
Semi-supervised training methods need reliable pseudo labels for unlabeled data. The current state-of-the-art methods based on pseudo labeling utilize only high-confidence predictions, whereas poor confidence predictions are discarded. This paper presents a novel approach to generate high-quality pseudo labels for unlabeled data. It utilizes predictions with high- and low-confidence levels to generate refined labels and then validates the accuracy of those predictions through bi-directional object tracking. The bi-directional object tracker leverages both past and future information to recover missing labels and increase the accuracy of the generated pseudo labels. This method can also substantially reduce the effort and time needed in label creation compared to the conventional manual labeling. The proposed method utilizes a buffer to accumulate detection labels (bounding boxes) predicted by the object detector. These labels are refined for accuracy though forward and backward tracking, ultimately constructing the final set of pseudo labels. The method is integrated in the YOLOv5 object detector and tested on the BDD100K dataset. Through the experiments, we demonstrate the effectiveness of the proposed scheme in automating the process of pseudo label generation with notably higher accuracy than the recent state-of-the-art pseudo label generation schemes. The results show that the proposed method outperforms previous methods in terms of mean average precision (mAP), label generation accuracy, and speed. Using the bi-directional recovery method, an increase in mAP@50 for the BDD100K dataset by 0.52% is achieved, and for the Waymo dataset, it provides an improvement of mAP@50 by 8.7% to 9.9% compared to 8.1% of the existing method when pre-training with 10% of the dataset. An improvement by 2.1% to 2.9% is achieved as compared to 1.7% of the existing method when pre-training with 20% of the dataset. Overall, the improved method leads to a significant enhancement in detection accuracy, achieving higher mAP scores across various datasets, thus demonstrating its robustness and effectiveness in diverse conditions. Full article
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29 pages, 63676 KiB  
Article
Color Image Encryption Based on a Novel Fourth-Direction Hyperchaotic System
by Zhuoyi Lei, Jiacheng Yang, Hanshuo Qiu, Xiangzi Zhang and Jizhao Liu
Electronics 2024, 13(12), 2229; https://doi.org/10.3390/electronics13122229 - 7 Jun 2024
Abstract
Neuromorphic computing draws inspiration from the brain to design energy-efficient hardware for information processing, enabling highly complex tasks. In neuromorphic computing, chaotic phenomena describe the nonlinear interactions and dynamic behaviors. Chaotic behavior can be utilized in neuromorphic computing to accomplish complex information processing [...] Read more.
Neuromorphic computing draws inspiration from the brain to design energy-efficient hardware for information processing, enabling highly complex tasks. In neuromorphic computing, chaotic phenomena describe the nonlinear interactions and dynamic behaviors. Chaotic behavior can be utilized in neuromorphic computing to accomplish complex information processing tasks; therefore, studying chaos is crucial. Today, more and more color images are appearing online. However, the generation of numerous images has also brought about a series of security issues. Ensuring the security of images is crucial. We propose a novel fourth-direction hyperchaotic system in this paper. In comparison to low-dimensional chaotic systems, the proposed hyperchaotic system exhibits a higher degree of unpredictability and various dynamic behaviors. The dynamic behaviors include fourth-direction hyperchaos, third-direction hyperchaos, and second-direction hyperchaos. The hyperchaotic system generates chaotic sequences. These chaotic sequences are the foundation of the encryption scheme discussed in this paper. Images are altered by employing methods such as row and column scrambling as well as diffusion. These operations will alter both the pixel values and positions. The proposed encryption scheme has been analyzed through security and application scenario analyses. We perform a security analysis to evaluate the robustness and weaknesses of the encryption scheme. Moreover, we conduct an application scenario analysis to help determine the practical usability and effectiveness of the encryption scheme in real-world situations. These analyses demonstrate the efficiency of the encryption scheme. Full article
(This article belongs to the Special Issue Recent Advances and Related Technologies in Neuromorphic Computing)
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12 pages, 3653 KiB  
Article
Self-Incompatibility in Devil’s Potato (Echites umbellatus Jacq., Apocynaceae) May Explain Why Few Flowers Set Fruit
by Suzanne Koptur, Andrea Salas Primoli, Imeña Valdes and Maha Nusrat
Biology 2024, 13(6), 423; https://doi.org/10.3390/biology13060423 - 7 Jun 2024
Abstract
Pollinators are needed for the reproduction of Echites umbellatus, and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species’ long, twisted floral tube. Though plants produce many flowers over a period of several months, [...] Read more.
Pollinators are needed for the reproduction of Echites umbellatus, and only sphingid moths have mouthparts long enough to reach the nectar at the bottom of the species’ long, twisted floral tube. Though plants produce many flowers over a period of several months, one observes very few fruits in nature. We asked: (1) Are plants self-compatible, or do they need pollen from another individual to set fruit and seed? (2) Are cross-pollinations between unrelated individuals more successful than crosses with relatives? (3) How does the relatedness of pollen and ovule parent plants affect fruit set, seed number, and seed quality? We investigated the breeding system of E. umbellatus by collecting fruits from seven sites, growing plants and performing hand pollinations over a period of several years, collecting and measuring fruits and counting seeds. Echites umbellatus is self-incompatible, though some individuals produce fruit by self-pollination. Cross-pollinations between unrelated individuals set the most fruit (59%), and those that were self-pollinated set the least (9%). Fruit set from cross-pollinations between related individuals was intermediate (32%). Although the number of seeds per fruit did not differ significantly among pollination treatments, fruits from self-pollinations had substantially fewer viable seeds than outcrossed fruits, with fruits from sibling crosses being intermediate. There were higher levels of self-compatibility in the fragment populations compared with plants from intact habitats. Self-incompatibility may explain why fruit set is low in this plant species; future investigation into the breakdown of self-incompatibility in smaller populations is warranted. Full article
(This article belongs to the Section Ecology)
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20 pages, 8983 KiB  
Article
Analysing the Spatio-Temporal Variations of Urban Street Summer Solar Radiation through Historical Street View Images: A Case Study of Shanghai, China
by Lei Wang, Longhao Zhang and Jie He
ISPRS Int. J. Geo-Inf. 2024, 13(6), 190; https://doi.org/10.3390/ijgi13060190 - 7 Jun 2024
Abstract
Understanding solar radiation in urban street spaces is crucial for comprehending residents’ environmental experiences and enhancing their quality of life. However, existing studies rarely focus on the patterns of urban street solar radiation over time and across different urban and suburban areas. In [...] Read more.
Understanding solar radiation in urban street spaces is crucial for comprehending residents’ environmental experiences and enhancing their quality of life. However, existing studies rarely focus on the patterns of urban street solar radiation over time and across different urban and suburban areas. In this study, street view images from the summers of 2013 and 2019 in Shanghai were used to calculate solar radiation in urban street spaces. The results show a general decrease in street solar radiation in 2019 compared to 2013, with an average drop of 12.34%. The decrease was most significant in October (13.47%) and least in May (11.71%). In terms of solar radiation data gathered from street view sampling points, 76.57% showed a decrease, while 23.43% showed an increase. Spatially, solar radiation decreased by 79.66% for every additional 1.5 km from the city centre. In summary, solar radiation generally shows a decreasing trend, with significant variations between different areas. These findings are vitally important for guiding urban planning, optimising green infrastructure, and enhancing the urban ecological environment, further promoting sustainable urban development and improving residents’ quality of life. Full article
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12 pages, 2412 KiB  
Article
Electroanalytical Platform for Rapid E. coli O157:H7 Detection in Water Samples
by Kundan Kumar Mishra, Vikram Narayanan Dhamu, Chesna Jophy, Sriram Muthukumar and Shalini Prasad
Biosensors 2024, 14(6), 298; https://doi.org/10.3390/bios14060298 - 7 Jun 2024
Abstract
There is a pressing need to enhance early detection methods of E. coli O157:H7 to mitigate the occurrence and consequences of pathogenic contamination and associated outbreaks. This study highlights the efficacy of a portable electrochemical sensing platform that operates without faradaic processes towards [...] Read more.
There is a pressing need to enhance early detection methods of E. coli O157:H7 to mitigate the occurrence and consequences of pathogenic contamination and associated outbreaks. This study highlights the efficacy of a portable electrochemical sensing platform that operates without faradaic processes towards detecting and quantifying E. coli O157:H7. It is specifically tailored for quick identification in potable water. The assay processing time is approximately 5 min, addressing the need for swift and efficient pathogen detection. The sensing platform was constructed utilizing specific, monoclonal E. coli antibodies, based on single-capture, non-faradaic, electrochemical immunoassay principles. The E. coli sensor assay underwent testing over a wide concentration range, spanning from 10 to 105 CFU/mL, and a limit of detection (LoD) of 1 CFU/mL was demonstrated. Significantly, the sensor’s performance remained consistent across studies, with both inter- and intra-study coefficients of variation consistently below 20%. To evaluate real-world feasibility, a comparative examination was performed between laboratory-based benchtop data and data obtained from the portable device. The proposed sensing platform exhibited remarkable sensitivity and selectivity, enabling the detection of minimal E. coli concentrations in potable water. This successful advancement positions it as a promising solution for prompt on-site detection, characterized by its portability and user-friendly operation. This study presents electrochemical-based sensors as significant contributors to ensuring food safety and public health. They play a crucial role in preventing the occurrence of epidemics and enhancing the supervision of water quality. Full article
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13 pages, 5785 KiB  
Article
Design of Debondable PU Coating for Degradation on Demand
by David De Smet and Myriam Vanneste
Coatings 2024, 14(6), 731; https://doi.org/10.3390/coatings14060731 - 7 Jun 2024
Abstract
Polyurethane (PU) coatings are applied on technical textiles for their superior properties. Up to now, PU-coated textiles are not recycled at end of life. Landfilling is still the most occurring way of processing PU waste. Next to looking to sustainable routes for processing [...] Read more.
Polyurethane (PU) coatings are applied on technical textiles for their superior properties. Up to now, PU-coated textiles are not recycled at end of life. Landfilling is still the most occurring way of processing PU waste. Next to looking to sustainable routes for processing PU waste, there is the drive towards bio-based polymers. With this regard, a bio-based trigger degradable PU coating specifically designed for textiles was developed. The PU was characterized via FT-IR, TGA, and DSC. The performance of the coating was assessed by examining the mechanical properties and the resistance to hydrostatic pressure initially and after washing. The developed bio-based PU coatings had a high tensile strength, were waterproof, and had excellent wash fastness at 40 °C. The coating could be easily debonded from the textile by immersion in a tetra-n-butylammoniumfluoride solution. FT-IR and microscopic analysis indicated that the coating was completely removed and that the polyester fabric was not degraded. Full article
(This article belongs to the Special Issue Surface Modification and Coating Techniques for Polymers)
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21 pages, 13275 KiB  
Article
Study of the Performance of Laser Melting Wear-Resistant Coatings on TC4 Titanium Alloy Surfaces
by Gaosheng Wang, Jingang Liu, Jianhua Yang, Sisi Liu, Lei Bu and Jianwen Chen
Coatings 2024, 14(6), 730; https://doi.org/10.3390/coatings14060730 - 7 Jun 2024
Abstract
To improve the wear resistance of TC4 titanium alloy, two types of wear-resistant coatings were applied to the surface using laser melting: Ni60 + 50% WC and d22 powder priming. The phase composition and microstructure of the coatings were characterized by X-ray diffractometry [...] Read more.
To improve the wear resistance of TC4 titanium alloy, two types of wear-resistant coatings were applied to the surface using laser melting: Ni60 + 50% WC and d22 powder priming. The phase composition and microstructure of the coatings were characterized by X-ray diffractometry (XRD), scanning electron microscopy (SEM), and energy spectroscopy (EDS). The mechanical properties of the coating were tested using an HV-1000 micro-Vickers hardness tester, an HRS-2M high-speed reciprocating friction and wear tester, and a WDW-100D electronic universal testing machine. The results show that Ni60 + 50% WC composite coating and d22 priming + (Ni60 + 50% WC) composite coating mainly consist of W2C, TiC, Ni17W3, Ni3Ti, and TixW1−x phases. Compared to the TC4 substrate, the microhardness of both coatings is significantly higher, approximately 2.8 times the microhardness of the substrate. In frictional wear experiments, the average friction factors of the two coatings and the TC4 substrate are 0.476, 0.55, and 0.865, respectively, and the wear of the two coatings is only 0.0559–0.0769 that of the TC4 substrate, with a significant increase in wear resistance, nearly 17 times higher than that of the substrate. The coating shows flaking, shallow abrasion marks, and granular debris, dominated by adhesive wear and fatigue wear, while the TC4 substrate shows more furrows on the surface, dominated by abrasive wear. The shear bond strengths of the Ni60 + 50% WC composite coating and the d22 powder primed + (Ni60 + 50% WC) composite coating were 188.19 MPa and 49.11 MPa, respectively. Conclusion: both coatings significantly improve the hardness and wear resistance of the TC4 titanium alloy substrate surface, with the Ni60 + 50% WC composite coating performing better in hardness, wear resistance, and bond strength. Full article
(This article belongs to the Special Issue Advanced Surface Technology and Application)
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17 pages, 2285 KiB  
Article
My Friend the Cross: Cross-Directed Prayer in Seventh-Century Monastic Communities and New Media Studies
by Daniel An
Religions 2024, 15(6), 708; https://doi.org/10.3390/rel15060708 - 7 Jun 2024
Abstract
While scholars have long recognized the central importance of the cross within Syriac-speaking Christian communities in late antique Mesopotamia, the question of how physical crosses functioned as aids for prayer has only recently begun to be explored. The present article addresses this question [...] Read more.
While scholars have long recognized the central importance of the cross within Syriac-speaking Christian communities in late antique Mesopotamia, the question of how physical crosses functioned as aids for prayer has only recently begun to be explored. The present article addresses this question with respect to East Syrian monastic communities in seventh-century Mesopotamia, focusing on the context of the monastic cell. Bringing together accounts of cross-directed prayer in Syriac monastic literature with archaeological evidence for crosses from the region, the article concludes that physical crosses played an important role as mediating devices of divine presence that were both always at hand and the frequent objects of monastics’ sensorial attention. These conclusions are subsequently discussed through the lens of recent research from the field of new media studies toward the goal of understanding how cross-directed prayer may have served to bridge monastic spirituality and sociality in Mesopotamia. Full article
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14 pages, 597 KiB  
Systematic Review
The Expression of microRNAs and Their Involvement in Recurrent Pregnancy Loss
by Maria-Markella Patronia, Anastasios Potiris, Despoina Mavrogianni, Eirini Drakaki, Theodoros Karampitsakos, Pavlos Machairoudias, Spyridon Topis, Athanasios Zikopoulos, Dionysios Vrachnis, Efthalia Moustakli, Chara Skentou, Ekaterini Domali, Nikolaos Vrachnis, Peter Drakakis and Sofoklis Stavros
J. Clin. Med. 2024, 13(12), 3361; https://doi.org/10.3390/jcm13123361 - 7 Jun 2024
Abstract
Background: Recurrent pregnancy loss refers to the spontaneous demise of two or more pregnancies before the 24 weeks of gestation. In almost half of the cases of recurrent miscarriages, the causes remain unknown since there is no reliable way of prognosis, early diagnosis, [...] Read more.
Background: Recurrent pregnancy loss refers to the spontaneous demise of two or more pregnancies before the 24 weeks of gestation. In almost half of the cases of recurrent miscarriages, the causes remain unknown since there is no reliable way of prognosis, early diagnosis, or treatment. Recent research has detected differential expression of certain miRNAs in reproductive system pathologies. Methods: The aim of the present review is to focus on microRNAs and their relationship with idiopathic recurrent miscarriages and to correlate miRNA expression with recurrent miscarriage and examine their potential role as biomarkers. Pubmed/Medline and Scopus databases were searched up to 31st January 2024 with terms related to recurrent pregnancy loss and miRNAs. Results: In total, 21 studies were selected for the review. A total of 75 different miRNAs were identified, showing a statistically significant differential expression. Around 40 miRNAs had increased expression, such as miR-520, miR-184 and miR-100-5p, 21 decreased, such as let-7c, and 14 had either increased or decreased expression depending on the study, such as miR-21. Conclusions: The dysregulation of miRNA expression is strongly associated with recurrent miscarriages. The circulating in the peripheral blood miRNAs, miR-100-5p and let-7c, might be utilized as biomarkers and establish a valuable non-invasive prognostic and diagnostic tool in the future. Full article
(This article belongs to the Section Obstetrics & Gynecology)
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13 pages, 1517 KiB  
Review
Pediatric Carotid Injury after Blunt Trauma and the Necessity of CT and CTA—A Narrative Literature Review
by Lukas Krüger, Oliver Kamp, Katharina Alfen, Jens Theysohn, Marcel Dudda and Lars Becker
J. Clin. Med. 2024, 13(12), 3359; https://doi.org/10.3390/jcm13123359 - 7 Jun 2024
Abstract
Background: Blunt carotid injury (BCI) in pediatric trauma is quite rare. Due to the low number of cases, only a few reports and studies have been conducted on this topic. This review will discuss how frequent BCI/blunt cerebrovascular injury (BCVI) on pediatric patients [...] Read more.
Background: Blunt carotid injury (BCI) in pediatric trauma is quite rare. Due to the low number of cases, only a few reports and studies have been conducted on this topic. This review will discuss how frequent BCI/blunt cerebrovascular injury (BCVI) on pediatric patients after blunt trauma is, what routine diagnostics looks like, if a computed tomography (CT)/computed tomography angiography (CTA) scan on pediatric patients after blunt trauma is always necessary and if there are any negative health effects. Methods: This narrative literature review includes reviews, systematic reviews, case reports and original studies in the English language between 1999 and 2020 that deal with pediatric blunt trauma and the diagnostics of BCI and BCVI. Furthermore, publications on the risk of radiation exposure for children were included in this study. For literature research, Medline (PubMed) and the Cochrane library were used. Results: Pediatric BCI/BCVI shows an overall incidence between 0.03 and 0.5% of confirmed BCI/BCVI cases due to pediatric blunt trauma. In total, 1.1–3.5% of pediatric blunt trauma patients underwent CTA to detect BCI/BCVI. Only 0.17–1.2% of all CTA scans show a positive diagnosis for BCI/BCVI. In children, the median volume CT dose index on a non-contrast head CT is 33 milligrays (mGy), whereas a computed tomography angiography needs at least 138 mGy. A cumulative dose of about 50 mGy almost triples the risk of leukemia, and a cumulative dose of about 60 mGy triples the risk of brain cancer. Conclusions: Given that a BCI/BCVI could have extensive neurological consequences for children, it is necessary to evaluate routine pediatric diagnostics after blunt trauma. CT and CTA are mostly used in routine BCI/BCVI diagnostics. However, since radiation exposure in children should be as low as reasonably achievable, it should be asked if other diagnostic methods could be used to identify risk groups. Trauma guidelines and clinical scores like the McGovern score are established BCI/BCVI screening options, as well as duplex ultrasound. Full article
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13 pages, 271 KiB  
Article
Psychological Distress, Academic Stress, and Burnout among Saudi Undergraduate Nursing Students
by Shaherah Yousef Andargeery, Murad H. Taani, Rania Ali Alhalwani and Heba E. El-Gazar
J. Clin. Med. 2024, 13(12), 3357; https://doi.org/10.3390/jcm13123357 - 7 Jun 2024
Abstract
Background: There is limited evidence on the association between psychological distress, academic stress, and burnout among Saudi nursing students. Clarifying such an association is crucial to understanding the factors associated with psychological distress and developing interventions to prevent it. Aim: To explore [...] Read more.
Background: There is limited evidence on the association between psychological distress, academic stress, and burnout among Saudi nursing students. Clarifying such an association is crucial to understanding the factors associated with psychological distress and developing interventions to prevent it. Aim: To explore the prevalence and association of psychological distress with academic stress and burnout among Saudi nursing students. Methods: A cross-sectional design was used, and 237 students participated from a nursing college in Riyadh, Saudi Arabia. Students’ demographics; the Depression, Anxiety, and Stress Scale; the Academic Stress Inventory; and the Maslach Burnout Inventory were used for data collection. Results: Most of the participants reported no-to-mild depression, anxiety, and stress. Stress related to studying in groups, time management, emotional exhaustion, depersonalization, and personal accomplishment were the significant predictors of psychological distress, explaining 52.1% of the variance. Conclusions: This study suggest implementing tailored mental health screenings and support services for nursing students, embedding mental health professionals in the program, and using telehealth or mobile apps for remote monitoring to ensure comprehensive care for nursing students. Future research should consider these predictors while designing strategies to decrease psychological distress among students. Full article
(This article belongs to the Section Mental Health)
11 pages, 986 KiB  
Article
Surgical Outcomes following Reoperation for Recurrent Intracranial Meningiomas
by Shunya Hanakita and Soichi Oya
J. Clin. Med. 2024, 13(12), 3356; https://doi.org/10.3390/jcm13123356 - 7 Jun 2024
Abstract
Background: We sometimes encounter refractory meningioma cases that are difficult to control, even after achieving a high resection rate or following radiation therapy (RT). In such cases, additional surgical resection might be attempted, but reports regarding outcomes of re-do surgery for recurrent meningiomas [...] Read more.
Background: We sometimes encounter refractory meningioma cases that are difficult to control, even after achieving a high resection rate or following radiation therapy (RT). In such cases, additional surgical resection might be attempted, but reports regarding outcomes of re-do surgery for recurrent meningiomas are scarce. Methods: This study was a retrospective review of patients who underwent re-do surgery for recurrent meningiomas. The risks of re-doing surgery were statistically analyzed. A comparative analysis between the patients who underwent primary surgery for intracranial meningiomas was also performed. Twenty-six patients underwent re-do surgeries for recurrent meningiomas. Results: At first re-do surgery, gross total resection was achieved in 20 patients (77%). The disease-free survival rate after the first re-do surgery was calculated as 73/58/44% at 1, 2, and 5 years, respectively. A significant factor affecting longer disease-free survival was WHO Grade 1 diagnosis at first re-do surgery (p = 0.02). Surgery-related risks were observed in 10 patients presenting a significant risk factor for skull base location (p = 0.04). When comparing with the risk at primary surgery, the risks of surgical site infection (p = 0.04) and significant vessel injury (p < 0.01) were significantly higher for the re-do surgery. Conclusions: Re-do surgery could increase surgery-related risks compared to the primary surgery; however, it could remain a crucial option, while the indication should be carefully examined in each case. Full article
(This article belongs to the Special Issue Diagnosis and Treatment of Brain Tumor)
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4 pages, 207 KiB  
Editorial
The Contribution of Internal and External Factors to Human Spatial Navigation
by Laura Piccardi, Raffaella Nori, Jose Manuel Cimadevilla and María Kozhevnikov
Brain Sci. 2024, 14(6), 585; https://doi.org/10.3390/brainsci14060585 - 7 Jun 2024
Abstract
Spatial navigation is a multifaceted cognitive function essential for planning and finding routes in one’s environment [...] Full article
10 pages, 776 KiB  
Article
The Integral Reactive Strength Index: An Accurate Measurement for Evaluating Drop Jump Performance in Sprinter Athletes
by Raynier Montoro-Bombú, Hugo Sarmento, Marije T. Elferink-Gemser, Armando Costa, Paulo Malico Sousa and Luís Rama
Appl. Sci. 2024, 14(12), 4964; https://doi.org/10.3390/app14124964 - 7 Jun 2024
Abstract
The reactive strength index (RSI) is a performance measure previously used to assess lower extremity performance; however, this study addresses limitations in its interpretation that need to be readdressed. The purpose of this study is twofold: to test the correlation of a new [...] Read more.
The reactive strength index (RSI) is a performance measure previously used to assess lower extremity performance; however, this study addresses limitations in its interpretation that need to be readdressed. The purpose of this study is twofold: to test the correlation of a new variable denominated integral reactive strength index (IRSI) with the RSI and to compare the flight time, ground contact time, jump height, RSI, reactive capacity, and IRSI between Olympic athletes in 100 m and 400 m. Ten elite male track and field athletes who qualified for the Olympics participated in this study (age = 24.9 ± 2.42 years; height = 1.75 ± 5.0 cm). They were divided into two groups, the first with five 100 m sprinters and the second group with five 400 m sprinters. The drop jump (DJ) attempts from 0.20 m were performed with the force plate 0.10 m away from the jump box. The DJ 0.30 m and DJ 0.40 m had a 0.15 m separation, and the DJ 0.50 m and DJ 0.60 m had a 0.20 m separation. The correlation analysis showed a high correlation (r = 0.805; p = 0.02) between the RSI and the IRSI. The comparisons between 400 m sprinters versus 100 m sprinters showed that there are no significant differences between the groups for any of the reactive strength variables (p > 0.05). Coaches of these sports’ specialties should take these criteria into account when developing plyometric programs and introduce the IRSI as an accurate measurement for evaluating DJ performance. Full article
(This article belongs to the Special Issue Biomechanics and Motor Control on Human Movement Analysis)
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16 pages, 1125 KiB  
Article
The Optimization of Frequency Distribution Based on Genetic Algorithm for Space Gravitational Wave Observatories
by Lixiao Zeng, Haojie Li, Weilai Yao, Jianyu Wang and Xindong Liang
Appl. Sci. 2024, 14(12), 4963; https://doi.org/10.3390/app14124963 - 7 Jun 2024
Abstract
The three spacecraft of the space gravitational wave antenna employ heterodyne interferometry to mitigate the effects of Doppler shift. Constrained by laser relative intensity noise (RIN) and the sampling frequency constraints of phase readout circuits, the widespread adoption of fixed offset frequencies effectively [...] Read more.
The three spacecraft of the space gravitational wave antenna employ heterodyne interferometry to mitigate the effects of Doppler shift. Constrained by laser relative intensity noise (RIN) and the sampling frequency constraints of phase readout circuits, the widespread adoption of fixed offset frequencies effectively regulates the frequency of heterodyne interferometric beat notes within a reasonable frequency domain of [5 MHz, 25 MHz]. In this work, a high-precision fitness genetic algorithm for heterodyne interferometry is utilized to generate the initial offset frequency distribution scheme. To address issues with unreasonable switching times and offset frequency settings in the initial scheme for partial frequency domains, optimization strategies are proposed from three aspects: frequency domain selection extension, switch times control, and numerical low frequency. Results demonstrate that the optimization of frequency domain selection extension narrows the reasonable frequency domain to [5 MHz, 15 MHz] and [7 MHz, 17 MHz]. Optimization of switch times control ensures that switching times of offset frequency distribution scheme generated under the settings of [6 MHz, 17 MHz] and wider frequency domains can be controlled within a reasonable range of 6 to 13 times. Fixed offset frequency settings are generally reduced by 24.3% after low-frequency optimization. This methodology and result can provide a reliable reference for Program Taiji and even related space gravitational wave antenna projects. Full article
(This article belongs to the Section Aerospace Science and Engineering)
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22 pages, 12643 KiB  
Article
Boosting the Performance of LLIE Methods via Unsupervised Weight Map Generation Network
by Shuichen Ji, Shaoping Xu, Nan Xiao, Xiaohui Cheng, Qiyu Chen and Xinyi Jiang
Appl. Sci. 2024, 14(12), 4962; https://doi.org/10.3390/app14124962 - 7 Jun 2024
Abstract
Over the past decade, significant advancements have been made in low-light image enhancement (LLIE) methods due to the robust capabilities of deep learning in non-linear mapping, feature extraction, and representation. However, the pursuit of a universally superior method that consistently outperforms others across [...] Read more.
Over the past decade, significant advancements have been made in low-light image enhancement (LLIE) methods due to the robust capabilities of deep learning in non-linear mapping, feature extraction, and representation. However, the pursuit of a universally superior method that consistently outperforms others across diverse scenarios remains challenging. This challenge primarily arises from the inherent data bias in deep learning-based approaches, stemming from disparities in image statistical distributions between training and testing datasets. To tackle this problem, we propose an unsupervised weight map generation network aimed at effectively integrating pre-enhanced images generated from carefully selected complementary LLIE methods. Our ultimate goal is to enhance the overall enhancement performance by leveraging these pre-enhanced images, therewith culminating the enhancement workflow in a dual-stage execution paradigm. To be more specific, in the preprocessing stage, we initially employ two distinct LLIE methods, namely Night and PairLIE, chosen specifically for their complementary enhancement characteristics, to process the given input low-light image. The resultant outputs, termed pre-enhanced images, serve as dual target images for fusion in the subsequent image fusion stage. Subsequently, at the fusion stage, we utilize an unsupervised UNet architecture to determine the optimal pixel-level weight maps for merging the pre-enhanced images. This process is adeptly directed by a specially formulated loss function in conjunction with the no-reference image quality algorithm, namely the naturalness image quality evaluator (NIQE). Finally, based on a mixed weighting mechanism that combines generated pixel-level local weights with image-level global empirical weights, the pre-enhanced images are fused to produce the final enhanced image. Our experimental findings demonstrate exceptional performance across a range of datasets, surpassing various state-of-the-art methods, including two pre-enhancement methods, involved in the comparison. This outstanding performance is attributed to the harmonious integration of diverse LLIE methods, which yields robust and high-quality enhancement outcomes across various scenarios. Furthermore, our approach exhibits scalability and adaptability, ensuring compatibility with future advancements in enhancement technologies while maintaining superior performance in this rapidly evolving field. Full article
(This article belongs to the Section Computing and Artificial Intelligence)
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19 pages, 5493 KiB  
Article
Enhancing Clay Soil’s Geotechnical Properties Utilizing Sintered Gypsum and Glass Powder
by Mehrdad Nategh, Abdullah Ekinci, Anoosheh Iravanian and Murat Fahrioğlu
Appl. Sci. 2024, 14(12), 4961; https://doi.org/10.3390/app14124961 - 7 Jun 2024
Abstract
The growing number of end-of-life (EoL) photovoltaic (PV) panels as waste materials is forcing many countries to face the challenge of addressing this issue. The presented research explores the utilization of a by-product of this waste material, namely glass powder, with gypsum in [...] Read more.
The growing number of end-of-life (EoL) photovoltaic (PV) panels as waste materials is forcing many countries to face the challenge of addressing this issue. The presented research explores the utilization of a by-product of this waste material, namely glass powder, with gypsum in geotechnical engineering to improve clay-soil properties. The approach is to integrate these materials to address the sustainable management of EoL PV panels, an underutilized resource in geotechnical applications. Furthermore, the study extensively examines the physical properties of clay soil, gypsum, and glass powder. Composite samples are created by adjusting the proportions of gypsum (0%, 5%, 10%, and 15%) and glass powder (0%, 4%, 8%, and 12%) relative to the soil’s dry mass. Compaction processes are performed at dry densities of 1500 and 1700 kg/m3, with 7, 28, and 56 days of curing duration. Various tests, including ultrasonic pulse velocity (UPV), unconfined compressive strength (UCS), assessments of wet and dry cycle durability, scanning electron microscope (SEM) analyses, and X-ray diffraction (XRD) analyses, are conducted. The results reveal that gypsum consistently improves the soil’s strength and stiffness features, while initially adding glass powder reduces these properties before showing improvement at a 12% content. Correlations have been proposed to determine the unconfined compressive strength (qu), initial shear modulus (G0), and modulus of elasticity (E) to be acquired utilizing just a single test. Moreover, a correlation has been developed to predict the unconfined compressive strength and elastic modulus of any specimen through non-destructive testing. Additionally, microstructural analyses unveil intricate interactions, showcasing the progress of pozzolanic reactions, identifying silicon-rich compounds from glass powder, and elucidating how additives transform soil structure. Full article
(This article belongs to the Section Civil Engineering)
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24 pages, 4670 KiB  
Article
AI-Based Decision Support System Optimizing Wireless Sensor Networks for Consumer Electronics in E-Commerce
by Mohammed Salem Basingab, Hatim Bukhari, Suhail H. Serbaya, Georgios Fotis, Vasiliki Vita, Stylianos Pappas and Ali Rizwan
Appl. Sci. 2024, 14(12), 4960; https://doi.org/10.3390/app14124960 - 7 Jun 2024
Abstract
The purpose of this study is to investigate the potential of AI technology in developing a decision support system that can improve the effectiveness of wireless sensor networks (WSNs) in e-commerce, specifically in enhancing the features of consumer electronics. This research project is [...] Read more.
The purpose of this study is to investigate the potential of AI technology in developing a decision support system that can improve the effectiveness of wireless sensor networks (WSNs) in e-commerce, specifically in enhancing the features of consumer electronics. This research project is focused on optimizing wireless sensor networks for e-commerce consumer electronics by incorporating AI-based decision support systems. The primary objective of this study is to enhance energy efficiency and performance in online shopping platforms. Various algorithms and methodologies are proposed and assessed, including Adaptive Clustering, the Path Selection Algorithm, Fuzzy Logic-Controlled Energy Management, the Genetic Algorithm for Resource Allocation, and Deep Sleep Scheduling. These techniques improve network efficiency and reduce power consumption in e-commerce applications. The study demonstrates that integrating AI in consumer electronics can result in a remarkable 40% increase in energy efficiency. Comparative analyses conducted through simulations and real-world assessments indicate that the proposed methodology outperforms traditional techniques by 35%. This research underscores the vital role of AI in enhancing network performance and energy efficiency in e-commerce. The results suggest that implementing AI-driven strategies in wireless sensor networks for consumer electronics can significantly improve online shopping experiences. AI-based decision support systems can optimize wireless sensor networks for consumer electronics, improving energy efficiency and network performance on online shopping platforms. Full article
(This article belongs to the Special Issue Novel Research and Applications on Optimization Algorithms)
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19 pages, 1880 KiB  
Article
Retrospective, Observational Analysis on the Impact of SARS-CoV-2 Variant Omicron in Hospitalized Immunocompromised Patients in a German Hospital Network—The VISAGE Study
by Irit Nachtigall, Stefan Kwast, Sven Hohenstein, Sebastian König, Phi Long Dang, Johannes Leiner, Nicola Giesen, Benjamin Thomas Schleenvoigt, Marzia Bonsignore, Andreas Bollmann, Ralf Kuhlen and Fungwe Jah
Vaccines 2024, 12(6), 634; https://doi.org/10.3390/vaccines12060634 - 7 Jun 2024
Abstract
Aims: Endemic SARS-CoV-2 infections still burden the healthcare system and represent a considerable threat to vulnerable patient cohorts, in particular immunocompromised (IC) patients. This study aimed to analyze the in-hospital outcome of IC patients with severe SARS-CoV-2 infection in Germany. Methods: This retrospective, [...] Read more.
Aims: Endemic SARS-CoV-2 infections still burden the healthcare system and represent a considerable threat to vulnerable patient cohorts, in particular immunocompromised (IC) patients. This study aimed to analyze the in-hospital outcome of IC patients with severe SARS-CoV-2 infection in Germany. Methods: This retrospective, observational study, analyzed administrative data from inpatient cases (n = 146,324) in 84 German Helios hospitals between 1 January 2022 and 31 December 2022 with regard to in-hospital outcome and health care burden in IC patients during the first 12 months of Omicron dominance. As the primary objective, in-hospital outcomes of patients with COVID-19-related severe acute respiratory infection (SARI) were analyzed by comparing patients with (n = 2037) and without IC diagnoses (n = 14,772). Secondary analyses were conducted on IC patients with (n = 2037) and without COVID-19-related SARI (n = 129,515). A severe in-hospital outcome as a composite endpoint was defined per the WHO definition if one of the following criteria were met: intensive care unit (ICU) treatment, mechanical ventilation (MV), or in-hospital death. Results: In total, 12% of COVID-related SARI cases were IC patients, accounting for 15% of ICU admissions, 15% of MV use, and 16% of deaths, resulting in a higher prevalence of severe in-hospital courses in IC patients developing COVID-19-related SARI compared to non-IC patients (Odds Ratio, OR = 1.4, p < 0.001), based on higher in-hospital mortality (OR = 1.4, p < 0.001), increased need for ICU treatment (OR = 1.3, p < 0.001) and mechanical ventilation (OR = 1.2, p < 0.001). Among IC patients, COVID-19-related SARI profoundly increased the risk for severe courses (OR = 4.0, p < 0.001). Conclusions: Our findings highlight the vulnerability of IC patients to severe COVID-19. The persistently high prevalence of severe outcomes in these patients in the Omicron era emphasizes the necessity for continuous in-hospital risk assessment and monitoring of IC patients. Full article
(This article belongs to the Section COVID-19 Vaccines and Vaccination)
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15 pages, 3791 KiB  
Article
Nano-Pulse Treatment Overcomes the Immunosuppressive Tumor Microenvironment to Elicit In Situ Vaccination Protection against Breast Cancer
by Anthony Nanajian, Megan Scott, Niculina I. Burcus, Brittney L. Ruedlinger, Edwin A. Oshin, Stephen J. Beebe and Siqi Guo
Vaccines 2024, 12(6), 633; https://doi.org/10.3390/vaccines12060633 - 7 Jun 2024
Abstract
We previously reported that nano-pulse treatment (NPT), a pulsed power technology, resulted in 4T1-luc mammary tumor elimination and a strong in situ vaccination, thereby completely protecting tumor-free animals against a second live tumor challenge. The mechanism whereby NPT mounts effective antitumor immune responses [...] Read more.
We previously reported that nano-pulse treatment (NPT), a pulsed power technology, resulted in 4T1-luc mammary tumor elimination and a strong in situ vaccination, thereby completely protecting tumor-free animals against a second live tumor challenge. The mechanism whereby NPT mounts effective antitumor immune responses in the 4T1 breast cancer predominantly immunosuppressive tumor microenvironment (TME) remains unanswered. In this study, orthotopic 4T1 mouse breast tumors were treated with NPT (100 ns, 50 kV/cm, 1000 pulses, 3 Hz). Blood, spleen, draining lymph nodes, and tumors were harvested at 4-h, 8-h, 1-day, 3-day, 7-day, and 3-month post-treatment intervals for the analysis of frequencies, death, and functional markers of various immune cells in addition to the suppressor function of regulatory T cells (Tregs). NPT was verified to elicit strong in situ vaccination (ISV) against breast cancer and promote both acute and long-term T cell memory. NPT abolished immunosuppressive dominance systemically and in the TME by substantially reducing Tregs, myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs). NPT induced apoptosis in Tregs and TAMs. It also functionally diminished the Treg suppression capacity, explained by the downregulation of activation markers, particularly 4-1BB and TGFβ, and a phenotypic shift from predominantly activated (CD44+CD62L) to naïve (CD44CD62L+) Tregs. Importantly, NPT selectively induced apoptosis in activated Tregs and spared effector CD4+ and CD8+ T cells. These changes were followed by a concomitant rise in CD8+CD103+ tissue-resident memory T cells and TAM M1 polarization. These findings indicate that NPT effectively switches the TME and secondary lymphatic systems from an immunosuppressive to an immunostimulatory state, allowing cytotoxic T cell function and immune memory formation to eliminate cancer cells and account for the NPT in situ vaccination. Full article
(This article belongs to the Special Issue Advances in Cancer Vaccines: From Bench to Bedside)
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11 pages, 3619 KiB  
Communication
Myeloid Nrf2 Protects against Neonatal Oxidant-Stress-Induced Lung Inflammation and Alveolar Simplification in Mice
by Chandra Mohan Tamatam, Lalith Kumar Venkareddy, Aparna Ankireddy, Narsa Machireddy and Sekhart P. Reddy
Antioxidants 2024, 13(6), 698; https://doi.org/10.3390/antiox13060698 - 7 Jun 2024
Abstract
Bronchopulmonary dysplasia (BPD) is a chronic condition affecting preterm infants, characterized by lung alveolar simplification/hypoalveolarization and vascular remodeling. The nuclear factor erythroid 2 like 2 (Nfe2l2, or Nrf2) plays a critical role in the cytoprotective response to neonatal hyperoxia, and its global deficiency [...] Read more.
Bronchopulmonary dysplasia (BPD) is a chronic condition affecting preterm infants, characterized by lung alveolar simplification/hypoalveolarization and vascular remodeling. The nuclear factor erythroid 2 like 2 (Nfe2l2, or Nrf2) plays a critical role in the cytoprotective response to neonatal hyperoxia, and its global deficiency exacerbates hypoalveolarization in mice. The abnormal recruitment and activation of myeloid cells are associated with the pathogenesis of BPD. Therefore, we employed a genetic approach to investigate the role of myeloid Nrf2 in regulating hyperoxia-induced hypoalveolarization. Pups, both wild-type (Nrf2f/f) and those with a myeloid Nrf2 deletion (abbreviated as Nrf2∆/∆mye), were exposed to hyperoxia for 72 h at postnatal day 1 (Pnd1), and then sacrificed at either Pnd4 or Pnd18 following a two-week recovery period. We analyzed the hypoalveolarization, inflammation, and gene expression related to cytoprotective and inflammatory responses in the lungs of these pups. The hypoalveolarization induced by hyperoxia was significantly greater in Nrf2∆/∆mye pups compared to their Nrf2f/f counterparts (35.88% vs. 21.01%, respectively) and was accompanied by increased levels of inflammatory cells and IL-1β activation in the lungs. Antioxidant gene expression in response to neonatal hyperoxia was lower in Nrf2∆/∆mye pups compared to their Nrf2f/f counterparts. Furthermore, Nrf2-deficient macrophages exposed to hyperoxia exhibited markedly decreased cytoprotective gene expression and increased IL-1β levels compared to Nrf2-sufficient cells. Our findings demonstrate the crucial role of myeloid Nrf2 in mitigating hyperoxia-induced lung hypoalveolarization and inflammatory responses in neonatal mice. Full article
(This article belongs to the Special Issue Oxidative Stress and NRF2 in Health and Disease)
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