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18 pages, 1522 KiB  
Article
Novel Liposome–Gel Formulations Containing a Next Generation Postbiotic: Characterization, Rheological, Stability, Release Kinetic, and In Vitro Antimicrobial Activity Studies
by Halise Betül Gökçe and İsmail Aslan
Gels 2024, 10(11), 746; https://doi.org/10.3390/gels10110746 (registering DOI) - 15 Nov 2024
Abstract
In recent years, in addition to the positive effects of probiotics and prebiotics on health, increasing research has shown that postbiotics also have significant potential in the health field. Postbiotics are bioactive components produced by probiotic bacteria during fermentation and may exhibit antimicrobial [...] Read more.
In recent years, in addition to the positive effects of probiotics and prebiotics on health, increasing research has shown that postbiotics also have significant potential in the health field. Postbiotics are bioactive components produced by probiotic bacteria during fermentation and may exhibit antimicrobial activity. This study investigated the antimicrobial effects of liposomal postbiotics formulated in gel. Various postbiotic-containing liposomal systems have been developed and optimized to prepare formulations. Optimized liposomes and liposomal postbiotic-containing gel forms were examined in terms of particle size, polydispersity index, zeta potential, structural properties, encapsulation efficiency, permeability, release profiles, and stability. Finally, the antimicrobial activities of the postbiotics and the optimum gel formulation LG1 were evaluated on Pseudomonas aeruginosa, Staphylococcus aureus, Escherichia coli, Enterococcus hirae, and Candida albicans strains using disk diffusion and microdilution methods. The optimum liposome formulation L1 was determined to have a particle size of 185.32 ± 0.80 nm, a polydispersity index of 0.206 ± 0.012, a zeta potential of 35.0 ± 0.5 mV, and an encapsulation efficiency of 17.52%. Its permeability was determined as 51.52% at the end of 6 h. In vitro release studies showed that the drug release profile was in accordance with first-order kinetics and suitable for controlled release. The findings show that formulated postbiotics have similar antimicrobial activity to free postbiotics. These results suggest that liposomal gel formulations support the antimicrobial effects of postbiotics while providing advantages of use. In conclusion, the findings contribute to a better understanding of the antimicrobial potential of postbiotics and lipogelosomal postbiotics and optimize their use in pharmaceutical applications. Full article
13 pages, 6097 KiB  
Article
Impact of Urban Surfaces on Microclimatic Conditions and Thermal Comfort in Burdur, Türkiye
by Maomao Zhang, İlker Yiğit, Fatih Adigüzel, Chunguang Hu, Enqing Chen, Ahmet Emrah Siyavuş, Necmettin Elmastaş, Mustafa Ustuner and Aşır Yüksel Kaya
Atmosphere 2024, 15(11), 1375; https://doi.org/10.3390/atmos15111375 - 14 Nov 2024
Viewed by 485
Abstract
Rapid urbanization worldwide offers numerous benefits but also introduces challenges, particularly concerning urban climate comfort, which affects the physical and social well-being in cities. This study examined the microclimatic characteristics of the Burç neighborhood in the historical core of Burdur city, using ENVI-Met [...] Read more.
Rapid urbanization worldwide offers numerous benefits but also introduces challenges, particularly concerning urban climate comfort, which affects the physical and social well-being in cities. This study examined the microclimatic characteristics of the Burç neighborhood in the historical core of Burdur city, using ENVI-Met models with temperature, relative humidity, wind and PET data collected over a 33,665 m2 area at 06:00, 09:00, 12:00, 15:00, 18:00 and 21:00 on 15 August 2023. The analysis revealed that thermal comfort decreases significantly from 09:00 onwards, especially on hard surfaces like asphalt, concrete and parquet, which lack vegetation and intensify heat retention. By contrast, green areas were found to enhance bioclimatic comfort by reducing perceived temperatures by up to 20% in shaded and vegetated zones. Based on these findings, it is recommended that urban areas reduce heat-absorbing materials, such as asphalt and concrete and prioritize green spaces in landscape planning to improve thermal comfort and create more sustainable urban environments. Full article
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<p>Study area.</p>
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<p>Study area and urban land use information.</p>
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<p>Temperature values of the study area in terms of thermal comfort.</p>
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<p>Relative humidity values of the study area in terms of thermal comfort.</p>
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<p>Wind characteristics of the study area in terms of thermal comfort.</p>
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<p>PET characteristics of the study area in terms of thermal comfort.</p>
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<p>Thermal Perception characteristics of the study area in terms of thermal comfort.</p>
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9 pages, 445 KiB  
Article
Myopia Progression in School-Age Children During the COVID-19 Pandemic
by Gülce Gökgöz Özışık and Hayati Yilmaz
J. Clin. Med. 2024, 13(22), 6849; https://doi.org/10.3390/jcm13226849 - 14 Nov 2024
Viewed by 138
Abstract
Objectives: This study aimed to investigate changes in refraction error in myopic school-age children during the COVID-19 pandemic. Methods: The data of 825 myopic children aged 7–18 years were retrospectively screened from the hospital data access system. The cycloplegic prescriptions of the [...] Read more.
Objectives: This study aimed to investigate changes in refraction error in myopic school-age children during the COVID-19 pandemic. Methods: The data of 825 myopic children aged 7–18 years were retrospectively screened from the hospital data access system. The cycloplegic prescriptions of the patients in 2018, 2019, 2020, and 2021 were recorded. The patients were divided into three groups according to their ages: ≤10 years (Group A), 11–14 years (Group B), and ≥15 years (Group C). The mean refraction values and annual progression values were compared between the years and age groups. Results: The mean age of the patients was 13.8 ± 3.17 years. Statistical analysis for the overall sample indicated that the annual myopia progression significantly differed between 2018 and 2021 (−0.42 ± 0.37 and −0.53 ± 0.47, respectively) (p < 0.001), and there was also a significant difference in myopia progression observed in all years in the younger age group (−0.34 ± 0.44 for 2018, −0.50 ± 0.49 for 2019, and −0.76 ± 0.59 for 2020). The highest progression (−0.76 ± 0.59) was determined in the younger age group in 2020. Linear regression analysis showed a negative correlation between myopia progression from 2020 to 2021 and age (B = 0.049 and p < 0.001). Conclusions: Myopia progression has increased in school-age children during COVID-19, with the younger age group being more affected. During the COVID-19 pandemic, myopia progression in younger children has increased statistically significantly. Thus, at times when distance learning is required, it would be appropriate to plan by taking into account the myopia progression of children. Full article
(This article belongs to the Section Ophthalmology)
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<p>This graph illustrates the annual myopia progression from 2018 to 2021 across four age groups: patients aged ≤ 10 (Group A), 11–14 years (Group B), and ≥15 years (Group C), and the total sample. The data show that the youngest group (Group A) experienced a faster progression rate, especially during the 2020–2021 period. The SD (standard deviation) values, shown next to each point, reflect the variability in progression.</p>
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36 pages, 19042 KiB  
Article
Transmission of Spatial Experience in the Context of Sustainability of Urban Memory
by Sedef Nur Cankurt Semiz and Fatma Ahsen Özsoy
Sustainability 2024, 16(22), 9910; https://doi.org/10.3390/su16229910 - 13 Nov 2024
Viewed by 406
Abstract
Urban memory involves the re-creation of a city’s physical, historical, social, and cultural elements in the memories of its inhabitants. However, urban transformation and commercial tourism-oriented projects may threaten the continuity of this memory. This study aims to provide an understanding of the [...] Read more.
Urban memory involves the re-creation of a city’s physical, historical, social, and cultural elements in the memories of its inhabitants. However, urban transformation and commercial tourism-oriented projects may threaten the continuity of this memory. This study aims to provide an understanding of the relationship between urban memory and spatial experience while exploring how urban memory elements convey meanings to daily users and local inhabitants of a touristic settlement. The research focuses on Misi Village in Bursa, Turkey, a settlement with a 2000-year history known for its traditional architecture and natural beauty. Over the past two decades, local authorities have pursued extensive restoration projects to rebrand Misi Village as an Art and Tourism Village. The research employs the oral history method, focusing on two user groups: tourists and locals. The findings reveal that while tourists appreciate Misi Village for its natural beauty and recreational activities, they lack a deeper understanding of its history and the transformation of its identity. Instead, they mostly focus on commerce-oriented spatial experiences. In contrast, local residents emphasize daily life and traditional practices as they strive to sustain their livelihoods. By highlighting this difference, strategic planning is proposed to preserve Misi Village’s unique urban memory and promote sustainable, culturally centered tourism. Full article
(This article belongs to the Special Issue Resident Well-Being and Sustainable Tourism Development)
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<p>Location of Misi in Gümüştepe Neighborhood, Bursa, Turkey [authors].</p>
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<p>Historical appearance of Misi [<a href="#B72-sustainability-16-09910" class="html-bibr">72</a>].</p>
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<p>A building in Misi before restoration in the 1990s (<b>a</b>) [<a href="#B76-sustainability-16-09910" class="html-bibr">76</a>]; the same building after restoration in 2023 (<b>b</b>) [authors’ archive]; a street in Misi before restoration in the 1990s (<b>c</b>) [<a href="#B77-sustainability-16-09910" class="html-bibr">77</a>]; the same street after restoration in 2019 (<b>d</b>) [authors’ archive].</p>
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<p>A building in Misi before restoration in the 1990s (<b>a</b>) [<a href="#B76-sustainability-16-09910" class="html-bibr">76</a>]; the same building after restoration in 2023 (<b>b</b>) [authors’ archive]; a street in Misi before restoration in the 1990s (<b>c</b>) [<a href="#B77-sustainability-16-09910" class="html-bibr">77</a>]; the same street after restoration in 2019 (<b>d</b>) [authors’ archive].</p>
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<p>Main attractions of Misi [authors].</p>
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<p>The Silk House (<b>a</b>); the weaving workshop (<b>b</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>].</p>
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<p>The Intangible Cultural Heritage Museum (<b>a</b>); the handicrafts section (<b>b</b>) [<a href="#B81-sustainability-16-09910" class="html-bibr">81</a>].</p>
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<p>The Mysia Photography Museum (<b>a</b>); the display space (<b>b</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>].</p>
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<p>The Literature Museum and Archive (<b>a</b>);the display space (<b>b</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>].</p>
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<p>The Children’s Library (<b>a</b>); the storytelling hour (<b>b</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>].</p>
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<p>The Writing House (<b>a</b>); the accommodation space (<b>b</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>].</p>
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<p>The Art House (<b>a</b>) [<a href="#B78-sustainability-16-09910" class="html-bibr">78</a>]; a visiting artist from KONSERVE (<b>b</b>) [<a href="#B87-sustainability-16-09910" class="html-bibr">87</a>].</p>
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<p>The Art Café (<b>a</b>); the workshop organization (<b>b</b>) [<a href="#B88-sustainability-16-09910" class="html-bibr">88</a>].</p>
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<p>The Ethnography House (<b>a</b>) [authors’ archive]; the shadow play (<b>b</b>) [<a href="#B89-sustainability-16-09910" class="html-bibr">89</a>].</p>
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<p>The first boutique hotel (<b>a</b>); the second boutique hotel (<b>b</b>) [authors’ archive].</p>
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<p>The Riverbank Recreation Project (<b>a</b>) [<a href="#B92-sustainability-16-09910" class="html-bibr">92</a>]; Misi riverbank facilities in 2024 (<b>b</b>) [authors’ archive].</p>
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<p>A picture from the trekking trail (<b>a</b>); a picture from the cycling trail (<b>b</b>) [<a href="#B93-sustainability-16-09910" class="html-bibr">93</a>].</p>
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<p>The bread making workshop (<b>a</b>) [<a href="#B95-sustainability-16-09910" class="html-bibr">95</a>]; the performance show (<b>b</b>) [<a href="#B94-sustainability-16-09910" class="html-bibr">94</a>].</p>
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<p>Steps of the research process [authors].</p>
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19 pages, 1272 KiB  
Article
Hybrid Oversampling and Undersampling Method (HOUM) via Safe-Level SMOTE and Support Vector Machine
by Duygu Yilmaz Eroglu and Mestan Sahin Pir
Appl. Sci. 2024, 14(22), 10438; https://doi.org/10.3390/app142210438 - 13 Nov 2024
Viewed by 293
Abstract
The improvements in collecting and processing data using machine learning algorithms have increased the interest in data mining. This trend has led to the development of real-life decision support systems (DSSs) in diverse areas such as biomedical informatics, fraud detection, natural language processing, [...] Read more.
The improvements in collecting and processing data using machine learning algorithms have increased the interest in data mining. This trend has led to the development of real-life decision support systems (DSSs) in diverse areas such as biomedical informatics, fraud detection, natural language processing, face recognition, autonomous vehicles, image processing, and each part of the real production environment. The imbalanced datasets in some of these studies, which result in low performance measures, have highlighted the need for additional efforts to address this issue. The proposed method (HOUM) is used to address the issue of imbalanced datasets for classification problems in this study. The aim of the model is to prevent the overfitting problem caused by oversampling and valuable data loss caused by undersampling in imbalanced data and obtain successful classification results. The HOUM is a hybrid approach that tackles imbalanced class distribution challenges, refines datasets, and improves model robustness. In the first step, majority-class data points that are distant from the decision boundary obtained via SVM are reduced. If the data are not balanced, SLS is employed to augment the minority-class data. This loop continues until the dataset becomes balanced. The main contribution of the proposed method is reproducing informative minority data using SLS and diminishing non-informative majority data using the SVM before applying classification techniques. Firstly, the efficiency of the proposed method, the HOUM, is verified by comparison with the SMOTE, SMOTEENN, and SMOTETomek techniques using eight datasets. Then, the results of the W-SIMO and RusAda algorithms, which were developed for imbalanced datasets, are compared with those of the HOUM. The strength of the HOUM is revealed through this comparison. The proposed HOUM algorithm utilizes a real dataset obtained from a project endorsed by The Scientific and Technical Research Council of Turkey. The collected data include quality control and processing parameters of yarn data. The aim of this project is to prevent yarn breakage errors during the weaving process on looms. This study introduces a decision support system (DSS) designed to prevent yarn breakage during fabric weaving. The high performance of the algorithm may encourage producers to manage yarn flow and enhance the HOUM’s efficiency as a DSS. Full article
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<p>Hyperplane and margins for an SVM for samples with two classes.</p>
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<p>Network graph of ANN with one hidden layer and one output neuron.</p>
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<p>The main procedure of the HOUM: (<b>A</b>) SVM implementation. (<b>B</b>) Selecting majority data far from the decision limit. (<b>C</b>) Performing instance reduction. (<b>D</b>) Oversampling via SLS. Black dots: majority data; blue stars: minority data; red dots: data selected from the majority class for removal; red stars: oversampled minority data.</p>
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<p>Flowchart of the proposed HOUM algorithm.</p>
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9 pages, 1737 KiB  
Case Report
Invasive Aspergillosis with Cavernous Sinus Thrombosis Following High-Dose Corticosteroid Therapy: A Challenging Case of Rhino-Orbital-Cerebral Mycosis
by Faruk Karakeçili, Orçun Barkay, Betül Sümer, Umut Devrim Binay, Kemal Buğra Memiş, Özlem Yapıcıer and Mecdi Gürhan Balcı
J. Fungi 2024, 10(11), 788; https://doi.org/10.3390/jof10110788 - 13 Nov 2024
Viewed by 331
Abstract
Invasive aspergillosis is a rare but severe fungal infection primarily affecting immunocompromised individuals. The Coronavirus Disease-2019 (COVID-19) pandemic has introduced new complexities in managing aspergillosis due to the widespread use of corticosteroids for treating COVID-19-related respiratory distress, which can increase susceptibility to fungal [...] Read more.
Invasive aspergillosis is a rare but severe fungal infection primarily affecting immunocompromised individuals. The Coronavirus Disease-2019 (COVID-19) pandemic has introduced new complexities in managing aspergillosis due to the widespread use of corticosteroids for treating COVID-19-related respiratory distress, which can increase susceptibility to fungal infections. Here, we present a challenging case of progressive cerebral aspergillosis complicated by cavernous sinus thrombosis (CST) in a 67-year-old male with a history of COVID-19. The patient, initially misdiagnosed with temporal arteritis, received pulse corticosteroid therapy twice before presenting with persistent left-sided headaches and vision loss. Cranial imaging revealed findings consistent with fungal sinusitis, Tolosa–Hunt syndrome, and orbital pseudotumor, which progressed despite initial antifungal therapy. Subsequent magnetic resonance imaging indicated an invasive mass extending into the left cavernous sinus and other intracranial structures, raising suspicion of aspergillosis. A transsphenoidal biopsy confirmed Aspergillus infection, leading to voriconazole therapy. Despite aggressive treatment, follow-up imaging revealed significant progression, with extension to the right frontal region and left cavernous sinus. The patient then developed visual impairment in the right eye and was diagnosed with CST secondary to fungal sinusitis. Management included a combination of systemic antifungals and antibiotics; however, the patient declined surgical intervention. This case underscores the diagnostic challenges and rapid progression associated with cerebral aspergillosis in post-COVID-19 patients treated with corticosteroids. This report highlights the need for heightened clinical suspicion and prompt, targeted interventions in similar cases to improve patient outcomes. Further research is required to understand the optimal management of invasive fungal infections. Full article
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<p>(<b>A</b>) An axial T2-weighted orbital MR image shows mucosal thickening in the sphenoid sinus and hypointense areas in the center (yellow asterisk). (<b>B</b>,<b>C</b>) Orbital MR sections in axial T2-weighted and post-contrast fat-suppressed T1-weighted imaging reveal inflammatory signal alterations in the retroconal adipose tissue (yellow arrow), along with thickening and enhanced contrast uptake in the extraocular muscles (red arrows) and optic nerve (white arrow). Additionally, there is contrast enhancement observed in the left cavernous sinus (red asterisk), suggesting Tolosa–Hunt syndrome or orbital pseudotumor in the left orbit.</p>
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<p>(<b>A</b>–<b>D</b>) Axial and coronal post-contrast fat-suppressed T1-weighted orbital MR images conducted one month apart demonstrate significant progression of the contrast-enhancing lesion encircling the left optic nerve and left internal carotid artery within the left cavernous sinus (red and black asterisks).</p>
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<p>Fungus image with septate hyphae in PAS staining.</p>
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<p>(<b>A</b>,<b>B</b>) Coronal T2-weighted and post-contrast fat-suppressed T1-weighted cranial MR images conducted in August 2022 reveal peripheral contrast-enhancing foci (red asterisks) encircled by extensive gyral edema (black asterisk) in the right frontal lobe.</p>
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19 pages, 1839 KiB  
Review
A Review of Non-Destructive Raman Spectroscopy and Chemometric Techniques in the Analysis of Cultural Heritage
by Burak Yogurtcu, Nur Cebi, Anıl Tevfik Koçer and Azime Erarslan
Molecules 2024, 29(22), 5324; https://doi.org/10.3390/molecules29225324 - 12 Nov 2024
Viewed by 471
Abstract
Today, there is an increasing concern and effort for protection, conservation, and restoration of cultural heritage materials. Non-invasive analytical methodologies such as Raman spectroscopy offers various advantages such as high speed, robust identification, low cost, and in-site analysis. Previous contributions highlighted the potential [...] Read more.
Today, there is an increasing concern and effort for protection, conservation, and restoration of cultural heritage materials. Non-invasive analytical methodologies such as Raman spectroscopy offers various advantages such as high speed, robust identification, low cost, and in-site analysis. Previous contributions highlighted the potential of Raman spectroscopy combined with multivariate statistics for identification and quality evaluation of cultural heritage materials such as paints, fiber, dyes, woods, stones, inks, and textile materials. Especially, application of chemometrics and multivariate statistics algorithms opens new horizons for scientists and inspectors. In conclusion, the paper provided an overview of the state-of-the-art uses of multivariate statistically equipped Raman spectroscopy methods for evaluation of cultural heritage and art materials with illustrations from previous research studies. Full article
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<p>The PCA results of FT-Raman spectra obtained from lead white–egg yolk paint samples (33.3%, 40%, 60%, and 66.7% LW) (<b>a</b>). The loading plots of chemometrics of PCA (PC1: 90%, PC2: 6%) (<b>b</b>). Reprinted from [<a href="#B56-molecules-29-05324" class="html-bibr">56</a>], Copyright (2014), with permission from John Wiley and Sons.</p>
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<p>3D discrimination pattern of architectural paints from 7 different manufacturers: Fuyan, Huarun, Dulux, Smoz, Nippon, Meffert, and Naerte. Reprinted from [<a href="#B33-molecules-29-05324" class="html-bibr">33</a>], Copyright (2021), with permission from Elsevier.</p>
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14 pages, 2106 KiB  
Article
A Novel Electrocardiographic Marker to Predict the Development of Preeclampsia: Frontal QRS-T Angle—A Prospective Pilot Study
by Elif Uçar, Kenan Toprak and Mesut Karataş
Medicina 2024, 60(11), 1856; https://doi.org/10.3390/medicina60111856 - 12 Nov 2024
Viewed by 304
Abstract
Background and Objectives: Preeclampsia, a pregnancy-induced hypertensive disorder, shares cardiovascular characteristics in etiology, prognosis, and fetomaternal risks. Electrocardiography plays a pivotal role in assessing cardiovascular risks. Beyond conventional predictors, identifying easily obtainable and reproducible electrocardiographic markers may significantly contribute to the early [...] Read more.
Background and Objectives: Preeclampsia, a pregnancy-induced hypertensive disorder, shares cardiovascular characteristics in etiology, prognosis, and fetomaternal risks. Electrocardiography plays a pivotal role in assessing cardiovascular risks. Beyond conventional predictors, identifying easily obtainable and reproducible electrocardiographic markers may significantly contribute to the early identification of individuals at risk of preeclampsia. In this study, we aimed to investigate the value of the Frontal QRS-T angle and other electrocardiographic parameters in predicting the development of preeclampsia. Materials and Methods: A total of 62 pregnant patients diagnosed with preeclampsia and 50 healthy pregnant patients as the control group were included in this study. The first- and third-trimester electrocardiographic parameters were compared within groups and between groups. Results: The Frontal QRS-T angle was significantly elevated in patients with preeclampsia compared to the controls (55.0 ± 40.8 vs. 19.5 ± 15.1; p = 0.002). The first-trimester Frontal QRS-T angles in the patients with preeclampsia were higher than those of the controls (29.5 ± 25.0 vs. 15.3 ± 11.5; p = 0.015). A high Frontal QRS-T angle independently marked preeclampsia development in antenatal and late pregnancy (p = 0.003 and p = 0.042, respectively). The diagnostic accuracy of the Frontal QRS-T angle in predicting preeclampsia surpassed other electrocardiographic parameters. Conclusions: This study shows that the Frontal QRS-T angle may be a candidate to be an independent predictor for the development of preeclampsia. In this context, the Frontal QRS-T angle, which is an electrocardiographic parameter, seems promising. Full article
(This article belongs to the Section Cardiology)
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<p>(<b>A</b>) A display of the electrocardiographic parameters on the ECG recording. (<b>B</b>) A simple calculation of the Frontal QRS-T angle from the ECG recording. The Frontal QRS-T angle, also referred to as the QRS-T axis difference or angle, is a measure of the absolute difference between the QRS axis and T wave axis on an ECG. It is calculated using the formula |QRS axis − T axis|. For angles greater than 180°, the value is adjusted by subtracting from 360° to keep the measurement within 0° to 180°.</p>
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<p>A comparison of the Frontal QRS-T angle values in the 1st and 3rd trimesters between the control group and the preeclampsia group. CG, control group; PG: preeclampsia group.</p>
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<p>Independent electrocardiographic predictors (*) of preeclampsia: Frontal QRS-T A3, Frontal QRS-T A1, and (SV1 + RV5)3. The numbers (1 or 3) next to the ECG parameters indicate which trimester the parameter belongs to. CI: Confidence Interval; OR: Odds Ratio; LB: Lower Band; UB: Upper Band.</p>
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<p>The ROC curve analysis shows that the 1st-trimester Frontal QRS-T angle (QRS-T A1) can predict the development of preeclampsia with 63% sensitivity and 62% specificity at the best cut-off value of 17.5°(AUC, 0.695; 95% CI, 0.598–0.791; <span class="html-italic">p</span> &lt; 0.001), and it shows that the 3rd-trimester Frontal QRS-T angle (QRS-T A3) can predict the development of preeclampsia with 70% sensitivity and 68% specificity at the best cut-off value of 28.0°(AUC, 0.736; 95% CI, 0.641–0.832; <span class="html-italic">p</span> &lt; 0.001). The preeclampsia predictive values of the QTd1, QTd3, and (SV1 + RV5)3 parameters were not statistically significant (<span class="html-italic">p</span> &gt; 0.05 for all). When the ROC curves of the 1st- and 3rd-trimester Frontal QRS-T angles underwent a pairwise comparison, there was no significant difference in their predictive power for preeclampsia (<span class="html-italic">p</span> = 0.508).</p>
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33 pages, 15029 KiB  
Article
Coupling Different Machine Learning and Meta-Heuristic Optimization Techniques to Generate the Snow Avalanche Susceptibility Map in the French Alps
by Enes Can Kayhan and Ömer Ekmekcioğlu
Water 2024, 16(22), 3247; https://doi.org/10.3390/w16223247 - 12 Nov 2024
Viewed by 356
Abstract
The focus of this study is to introduce a hybrid predictive framework encompassing different meta-heuristic optimization and machine learning techniques to identify the regions susceptible to snow avalanches. To accomplish this aim, the present research sought to acquire the best-performed model among nine [...] Read more.
The focus of this study is to introduce a hybrid predictive framework encompassing different meta-heuristic optimization and machine learning techniques to identify the regions susceptible to snow avalanches. To accomplish this aim, the present research sought to acquire the best-performed model among nine different hybrid scenarios encompassing three different meta-heuristics, namely particle swarm optimization (PSO), gravitational search algorithm (GSA), and Cuckoo Search (CS), and three different ML approaches, i.e., support vector classification (SVC), stochastic gradient boosting (SGB), and k-nearest neighbors (KNN), pertaining to different predictive families. According to diligent analysis performed with regard to the blinded testing set, the PSO-SGB illustrated the most satisfactory predictive performance with an accuracy of 0.815, while the precision and recall were found to be 0.824 and 0.821, respectively. The F1-score of the predictions was found to be 0.821, and the area under the receiver operating curve (AUC) was obtained to be 0.9. Despite attaining similar predictive success via the CS-SGB model, the time-efficiency analysis underscored the PSO-SGB, as the corresponding process consumed considerably less computational time compared to its counterpart. The SHapley Additive exPlanations (SHAP) implementation further informed that slope, elevation, and wind speed are the most contributing attributes to detecting snow avalanche susceptibility in the French Alps. Full article
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<p>Research flowchart.</p>
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<p>Study Domain.</p>
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<p>Generated layers for utilized factors. (<b>a</b>) elevation, (<b>b</b>) slope, (<b>c</b>) aspect, (<b>d</b>) profile curvature, (<b>e</b>) plan curvature, (<b>f</b>) LULC, (<b>g</b>) TPI, (<b>h</b>) TWI, (<b>i</b>) TRI, (<b>j</b>) lithology, (<b>k</b>) rainfall, (<b>l</b>) wind speed, (<b>m</b>) minimum temperature, (<b>n</b>) maximum temperature, (<b>o</b>) solar radiation, (<b>p</b>) snow depth, (<b>q</b>) distance to faults.</p>
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<p>Generated layers for utilized factors. (<b>a</b>) elevation, (<b>b</b>) slope, (<b>c</b>) aspect, (<b>d</b>) profile curvature, (<b>e</b>) plan curvature, (<b>f</b>) LULC, (<b>g</b>) TPI, (<b>h</b>) TWI, (<b>i</b>) TRI, (<b>j</b>) lithology, (<b>k</b>) rainfall, (<b>l</b>) wind speed, (<b>m</b>) minimum temperature, (<b>n</b>) maximum temperature, (<b>o</b>) solar radiation, (<b>p</b>) snow depth, (<b>q</b>) distance to faults.</p>
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<p>Convergence graph of PSO with respect to the validation set (<b>a</b>) SVC, (<b>b</b>) SGB, and (<b>c</b>) KNN.</p>
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<p>Convergence graph of GSA with respect to the validation set (<b>a</b>) SVC, (<b>b</b>) SGB, and (<b>c</b>) KNN.</p>
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<p>Convergence graph of CS with respect to the validation set (<b>a</b>) SVC, (<b>b</b>) SGB, and (<b>c</b>) KNN.</p>
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<p>Confusion matrices for ML models with regard to the testing set (<b>a</b>) PSO-SVC, (<b>b</b>) PSO-SGB, (<b>c</b>) PSO-KNN, (<b>d</b>) GSA-SVC, (<b>e</b>) GSA-SGB, (<b>f</b>) GSA-KNN, (<b>g</b>) CS-SVC, (<b>h</b>) CS-SGB, and (<b>i</b>) CS-KNN.</p>
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<p>ROC plots of the ML outcomes based on the testing set (<b>a</b>) PSO, (<b>b</b>) GSA, and (<b>c</b>) CS.</p>
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<p>Avalanche susceptibility map for testing set based on the best-performed model.</p>
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<p>SHAP summary plot.</p>
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14 pages, 5149 KiB  
Article
Obtaining Symmetrical Gradient Structure in Copper Wire by Combined Processing
by Andrey Volokitin, Irina Volokitina, Mehmet Seref Sonmez, Anastassiya Denissova and Zoya Gelmanova
Symmetry 2024, 16(11), 1515; https://doi.org/10.3390/sym16111515 - 12 Nov 2024
Viewed by 313
Abstract
Traditionally, structural wire is characterized by a homogeneous microstructure, where the average grain size in different parts of the wire is uniform. According to the classical Hall–Petch relationship, a homogeneous polycrystalline metal can be strengthened by decreasing the average grain size since an [...] Read more.
Traditionally, structural wire is characterized by a homogeneous microstructure, where the average grain size in different parts of the wire is uniform. According to the classical Hall–Petch relationship, a homogeneous polycrystalline metal can be strengthened by decreasing the average grain size since an increase in the volume fraction of grain boundaries will further impede the motion of dislocations. However, a decrease in the grain size inevitably leads to a decrease in the ductility and deformability of the material due to limited dislocation mobility. Putting a gradient microstructure into the wire has promising potential for overcoming the compromise between strength and ductility. This is proposed a new combined technology in this paper in order to obtain a gradient microstructure. This technology consists of deforming the wire in a rotating equal-channel step die and subsequent traditional drawing. Deformation of copper wire with a diameter of 6.5 mm to a diameter of 5.0 mm was carried out in three passes at room temperature. As a result of such processing, a gradient microstructure with a surface nanostructured layer (grain size ~400 nm) with a gradual increase in grain size towards the center of the wire was obtained. As a result, the microhardness in the surface zone was 1150 MPa, 770 Mpa in the neutral zone, and 685 MPa in the central zone of the wire. Such a symmetrical spread of microhardness, observed over the entire cross-section of the rod, is a direct confirmation of the presence of a gradient microstructure in deformed materials. The strength characteristics of the wire were doubled: the tensile strength increased from 335 MPa to 675 MPa, and the yield strength from 230 MPa to 445 MPa. At the same time, the relative elongation decreased from 20% to 16%, and the relative contraction from 28% to 23%. Despite the fact that the ductility of copper is decreased after cyclic deformation, its values remain at a fairly high level. The validity of all results is confirmed by numerous experiments using a complex of traditional and modern research methods, which include optical, scanning, and transmission microscopy; determination of mechanical properties under tension; and measurement of hardness and electrical resistance. These methods allow reliable interpretation of the fine microstructure of the wire and provide information on its strength, plastic, and electrical properties. Full article
(This article belongs to the Section Engineering and Materials)
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<p>Scheme of the proposed wire deformation technology: 1—wire; 2—setup housing; 3—drive gear; 4—intermediate gear; 5—rotating die case; 6—rotating die; 7—cold drawing die case; 8—drawing die.</p>
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<p>Samples for testing: (<b>a</b>)—determination of microhardness; (<b>b</b>)—tension.</p>
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<p>Optical micrographs of copper wire (transverse direction): (<b>a</b>)—initial; (<b>b</b>)—1 deformation cycle; (<b>c</b>)—2 deformation cycles; (<b>d</b>)—4 deformation cycles.</p>
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<p>Optical micrographs of copper wire (transverse direction): (<b>a</b>)—initial; (<b>b</b>)—1 deformation cycle; (<b>c</b>)—2 deformation cycles; (<b>d</b>)—4 deformation cycles.</p>
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<p>EBSD analysis after 3 passes of deformation (transverse direction): (<b>a</b>)—surface zone; (<b>b</b>)—intermediate zone; (<b>c</b>)—central zone.</p>
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<p>Histogram of misorientation angles obtained after 3 deformation passes: (<b>a</b>)—surface zone; (<b>b</b>)—intermediate zone; (<b>c</b>)—central zone.</p>
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<p>Microphotographs obtained after 3 passes of deformation (transverse direction): (<b>a</b>)—surface zone; (<b>b</b>)—intermediate zone; (<b>c</b>)—central zone.</p>
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<p>Microhardness distribution over the wire cross-section after each deformation pass.</p>
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<p>Tensile diagrams before (black line) and after (red line) deformation.</p>
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<p>Changes in mechanical properties graphs after each deformation pass: (<b>a</b>)—characteristics of strength; (<b>b</b>)—characteristics of plastic.</p>
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27 pages, 5077 KiB  
Article
Green Synthesis of Ag and Cu Nanoparticles Using E. telmateia Ehrh Extract: Coating, Characterization, and Bioactivity on PEEK Polymer Substrates
by Şakir Altınsoy, Kadriye Kızılbey and Hümeyra Berfin İlim
Materials 2024, 17(22), 5501; https://doi.org/10.3390/ma17225501 - 11 Nov 2024
Viewed by 459
Abstract
PEEK-based implant materials have gained increasing attention as an alternative to titanium due to their biocompatibility and bone-like elasticity. However, PEEK’s surface quality and wear resistance are lower than those of metals. This study aimed to enhance the bioactivity and surface quality of [...] Read more.
PEEK-based implant materials have gained increasing attention as an alternative to titanium due to their biocompatibility and bone-like elasticity. However, PEEK’s surface quality and wear resistance are lower than those of metals. This study aimed to enhance the bioactivity and surface quality of PEEK by coating it with silver and copper nanoparticles synthesized via a green method using Equisetum telmateia Ehrh. extract. PEEK samples (Ø 25 mm, 3 mm thick) were coated with single and double layers using spray (airbrush-spray) and drop-coating methods. Comprehensive analyses including SEM, EDX, FT-IR, UV-Vis, surface roughness, release studies, antioxidant and cytotoxicity activity, and antibacterial tests were conducted on the coated samples. The results demonstrated that AgNPs and CuNPs coatings significantly improved the surface quality of PEEK. SEM analysis revealed particle sizes ranging from 48 to 160 nm for AgNPs and 50–135 nm for CuNPs, with superior dispersion obtained using the airbrush-spray method. Surface roughness measurements showed a reduction of 17–33% for AgNPs-coated samples and 7–15% for CuNPs-coated samples compared to uncoated PEEK, with airbrush-spray coatings providing smoother surfaces. Antioxidant activity tests indicated that AgNPs provided 35% higher antioxidant activity compared to CuNPs. Additionally, antibacterial tests revealed that AgNPs exhibited a higher zone of inhibition (up to 14 mm for S. aureus and 18 mm for E. coli) compared to CuNPs, which exhibited zones of 8 mm and 10 mm, respectively. This study concludes that green-synthesized AgNPs, in particular, enhance the bioactivity and surface properties of PEEK, making it a promising material for biomedical applications such as infection-resistant implants. Full article
(This article belongs to the Topic Advanced Biomaterials: Processing and Applications)
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<p>The schematic view of the experimental steps.</p>
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<p>Size distribution of AgNPs (<b>a</b>) and CuNPs (<b>b</b>) by intensity.</p>
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<p>UV-Vis spectrum of AgNO<sub>3</sub> and AgNPs (<b>a</b>), and UV-Vis spectrum of CuSO<sub>4</sub> and CuNPs (<b>b</b>).</p>
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<p>FT-IR spectrum AgNO<sub>3</sub> and AgNPs (<b>a</b>), and PEEK samples coated with AgNPs (<b>b</b>).</p>
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<p>FT-IR spectrum CuSO<sub>4</sub>, CuNPs (<b>a</b>), and PEEK samples coated with CuNPs (<b>b</b>).</p>
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<p>SEM images of AgNPs (<b>a</b>) and CuNPs (<b>b</b>).</p>
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<p>SEM images of AgNPs using the drop-casting method: (<b>a</b>) single-layer coating; (<b>b</b>) double-layer coating.</p>
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<p>SEM images of AgNPs using the airbrush-spray method: (<b>a</b>) single-layer coating; (<b>b</b>) double-layer coating.</p>
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<p>SEM images of CuNPs using the drop-casting method: (<b>a</b>) single-layer coating; (<b>b</b>) double-layer coating.</p>
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<p>SEM images of CuNPs using the airbrush-spray method: (<b>a</b>) single-layer coating; (<b>b</b>) double-layer coating.</p>
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<p>EDS spectrum analyses of the PEEK.</p>
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<p>EDS spectrum of AgNPs (<b>a</b>) and CuNPs (<b>b</b>) synthesized using <span class="html-italic">E. telmateia</span> Ehrh. plant extract.</p>
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<p>EDS spectrum of AgNPs (<b>a</b>) and CuNPs (<b>b</b>) synthesized using <span class="html-italic">E. telmateia</span> Ehrh. plant extract.</p>
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<p>EDS spectrum of PEEK samples coated with AgNPs drop-casting single layer (<b>a</b>), double layer (<b>b</b>) and airbrush-spray single layer (<b>c</b>), double layer (<b>d</b>).</p>
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<p>EDS spectrum of PEEK samples coated with AgNPs drop-casting single layer (<b>a</b>), double layer (<b>b</b>) and airbrush-spray single layer (<b>c</b>), double layer (<b>d</b>).</p>
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<p>EDS spectrum of PEEK samples coated with CuNPs drop-casting single layer (<b>a</b>), double layer (<b>b</b>) and airbrush-spray single layer (<b>c</b>), double layer (<b>d</b>).</p>
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<p>EDS spectrum of PEEK samples coated with CuNPs drop-casting single layer (<b>a</b>), double layer (<b>b</b>) and airbrush-spray single layer (<b>c</b>), double layer (<b>d</b>).</p>
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<p>Surface roughness results.</p>
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<p>Antioxidant activity results.</p>
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<p>MTT test results of AgNPs (<b>a</b>) and CuNPs (<b>b</b>).</p>
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<p>Antibacterial activities of AgNPs and CuNPs.</p>
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26 pages, 558 KiB  
Article
Efficient Multiplicative Calculus-Based Iterative Scheme for Nonlinear Engineering Applications
by Mudassir Shams, Nasreen Kausar and Șomîtcă Ioana Alexandra
Mathematics 2024, 12(22), 3517; https://doi.org/10.3390/math12223517 - 11 Nov 2024
Viewed by 350
Abstract
It is essential to solve nonlinear equations in engineering, where accuracy and precision are critical. In this paper, a novel family of iterative methods for finding the simple roots of nonlinear equations based on multiplicative calculus is introduced. Based on theoretical research, a [...] Read more.
It is essential to solve nonlinear equations in engineering, where accuracy and precision are critical. In this paper, a novel family of iterative methods for finding the simple roots of nonlinear equations based on multiplicative calculus is introduced. Based on theoretical research, a novel family of simple root-finding schemes based on multiplicative calculus has been devised, with a convergence order of seven. The symmetry in the pie graph of the convergence–divergence areas demonstrates that the method is stable and consistent when dealing with nonlinear engineering problems. An extensive examination of the numerical results of the engineering applications is presented in order to assess the effectiveness, stability, and consistency of the recently established method in comparison to current methods. The analysis includes the total number of functions and derivative evaluations per iteration, elapsed time, residual errors, local computational order of convergence, and error graphs, which demonstrate our method’s better convergence behavior when compared to other approaches. Full article
(This article belongs to the Special Issue Mathematical and Numerical Methods in Biology and Engineering)
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<p>The percentage convergence and divergence of the numerical schemes <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> are provided from top left to end, respectively, for solving engineering applications in example 1.</p>
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<p>(<b>a</b>–<b>c</b>) The number of functions and its derivative evaluations, elapsed time and residual error of the iterative technique <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> for solving engineering applications in examples 1.</p>
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<p>The percentage convergence and divergence of the numerical schemes <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> are provided from top left to end, respectively, for solving engineering applications in example 2.</p>
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<p>(<b>a</b>–<b>c</b>) The number of functions and its derivative evaluations, elapsed time and residual error of the iterative technique <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> for solving engineering applications in examples 2.</p>
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<p>The percentage convergence and divergence of the numerical schemes <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> are provided from top left to end, respectively, for solving engineering applications in example 3.</p>
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<p>(<b>a</b>–<b>c</b>) The number of functions and its derivative evaluations, elapsed time and residual error of the iterative technique <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> for solving engineering applications in examples 3.</p>
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<p>The percentage convergence and divergence of the numerical schemes <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> are provided from top left to end, respectively, for solving engineering applications in example 4.</p>
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<p>(<b>a</b>–<b>c</b>) The number of functions and its derivative evaluations, elapsed time and residual error of the iterative technique <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> for solving engineering applications in examples 4.</p>
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<p>The percentage convergence and divergence of the numerical schemes <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> are provided from top left to end, respectively, for solving engineering applications in example 5.</p>
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<p>(<b>a</b>–<b>c</b>) The number of functions and its derivative evaluations, elapsed time and residual error of the iterative technique <math display="inline"><semantics> <mrow> <mrow> <msubsup> <mi>SR</mi> <mrow> <mn>1</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> <mo>−</mo> </mrow> <msubsup> <mi>SR</mi> <mrow> <mn>6</mn> </mrow> <mrow> <mo stretchy="false">[</mo> <mo>∗</mo> <mo stretchy="false">]</mo> </mrow> </msubsup> </mrow> </semantics></math> for solving engineering applications in examples 5.</p>
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12 pages, 2455 KiB  
Article
Effect of Mechanically Exfoliated Graphite Flakes on Morphological, Mechanical, and Thermal Properties of Epoxy
by Ayşenur Gül and Ali Reza Kamali
J. Compos. Sci. 2024, 8(11), 466; https://doi.org/10.3390/jcs8110466 - 11 Nov 2024
Viewed by 547
Abstract
Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic [...] Read more.
Carbon-reinforced polymer composites form an important category of advanced materials, and there is an increasing demand to enhance their performance using more convenient and scalable processes at low costs. In the present study, graphitic flakes were prepared by the mechanical exfoliation of synthetic graphite electrodes and utilized as an abundant and potentially low-cost filler to fabricate epoxy-based composites with different additive ratios of 1–10 wt.%. The morphological, structural, thermal, and mechanical properties of these composites were investigated. It was found that the thermal conductivity of the composites increases by adding graphite, and this increase mainly depends on the ratio of the graphite additive. The addition of graphite was found to have a diverse effect on the mechanical properties of the composites: the tensile strength of the composites decreases with the addition of graphite, whilst their compressive strength and elastic modulus are enhanced. The results demonstrate that incorporating 5 wt% of commercially available graphite into epoxy not only raises the thermal conductivity of the material from 0.223 to 0.485 W/m·K, but also enhances its compressive strength from 66 MPa to 72 MPa. The diverse influence of graphite provides opportunities to prepare epoxy composites with desirable properties for different applications. Full article
(This article belongs to the Special Issue Mechanical Properties of Composite Materials and Joints)
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<p>(<b>a</b>) The uniform suspension of graphite flakes, Jeffamine D-230, EPON 826, and NGDE used to prepare the samples for the (<b>b</b>) tensile, (<b>c</b>) compressive, and (<b>d</b>) thermal conductivity tests. (<b>e</b>) A close up of the setup used to measure the latter, in which a hot disk sensor is utilized.</p>
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<p>SEM micrographs of (<b>a</b>) the graphite powder used as the filler. The cross-section of (<b>b</b>) the epoxy and the composites produced by the addition of (<b>c</b>) 5 wt% and (<b>d</b>) 10 wt% graphite into the epoxy.</p>
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<p>XRD patterns of (<b>a</b>) the neat epoxy, (<b>b</b>) the graphite powder, and (<b>c</b>) the graphite/epoxy composite containing 5wt% graphite.</p>
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<p>FTIR spectrum of unmodified epoxy resin and epoxy resin containing 10 wt% graphite flakes.</p>
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<p>The properties of the graphite/epoxy composites at various graphite loading, comprising (<b>a</b>) the average values of thermal conductivity and (<b>b</b>) the average values of mechanical properties.</p>
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21 pages, 3077 KiB  
Article
Drone-Assisted Last-Mile Delivery Under Windy Conditions: Zero Pollution Solutions
by Özlem Gürel and Seyda Serdarasan
Smart Cities 2024, 7(6), 3437-3457; https://doi.org/10.3390/smartcities7060134 - 10 Nov 2024
Viewed by 643
Abstract
As cities expand and the global push for zero pollution intensifies, sustainable last-mile delivery (LMD) systems are essential to minimizing environmental and health impacts. This study addresses the need for more sustainable LMD by examining the integration of wind conditions into drone-assisted deliveries, [...] Read more.
As cities expand and the global push for zero pollution intensifies, sustainable last-mile delivery (LMD) systems are essential to minimizing environmental and health impacts. This study addresses the need for more sustainable LMD by examining the integration of wind conditions into drone-assisted deliveries, focusing on their effects on air and noise pollution in urban areas. We extend the flying sidekick traveling salesman problem (FSTSP) by incorporating meteorological factors, specifically wind, to assess drone delivery efficiency in varying conditions. Our results show that while drones significantly reduce greenhouse gas emissions compared to traditional delivery vehicles, their contribution to noise pollution remains a concern. This research highlights the environmental advantages of using drones, particularly in reducing CO2 emissions, while also emphasizing the need for further investigation into mitigating their noise impact. By evaluating the trade-offs between air and noise pollution, this study provides insights into developing more sustainable, health-conscious delivery models that contribute to smart city initiatives. The findings inform policy, urban planning, and logistics strategies aimed at achieving zero pollution goals and improving urban livability. Full article
(This article belongs to the Special Issue City Logistics and Smart Cities: Models, Approaches and Planning)
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<p>The relationship between air speed, ground speed, and wind speed while the drone travels to the arc (<span class="html-italic">i</span>, <span class="html-italic">j</span>) and the wind blowing from the north.</p>
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<p>Locations of the warehouse (in blue) and sample pharmacies (in red).</p>
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<p>Delivery time comparison across delivery scenarios: under northerly (N), northwesterly (NW), southwesterly (SW), and southerly (S) wind across Beaufort scales 2 to 5.</p>
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<p>Comparison of cumulative energy consumption for diesel and electric vehicles across delivery scenarios.</p>
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<p>Comparison of route cost for diesel and electric vehicles across delivery scenarios.</p>
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<p>Comparison of route cost for diesel and electric vehicles across delivery scenarios.</p>
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<p>Comparison of CO<sub>2</sub> emissions for diesel and electric vehicles across delivery scenarios.</p>
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<p>Comparison of CO<sub>2</sub> emissions for diesel and electric vehicles across delivery scenarios.</p>
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<p>Comparison of noise levels (dBs) across delivery scenarios.</p>
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16 pages, 865 KiB  
Review
Microcirculation: Current Perspective in Diagnostics, Imaging, and Clinical Applications
by Ugur Aksu, Berna Yavuz-Aksu and Nandu Goswami
J. Clin. Med. 2024, 13(22), 6762; https://doi.org/10.3390/jcm13226762 - 10 Nov 2024
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Abstract
This review discusses the pivotal role of microcirculation in maintaining tissue oxygenation and waste removal and highlights its significance in various pathological conditions. It delves into the cellular mechanisms underlying hemodynamic coherence, elucidating the roles of the endothelium, glycocalyx, and erythrocytes in sustaining [...] Read more.
This review discusses the pivotal role of microcirculation in maintaining tissue oxygenation and waste removal and highlights its significance in various pathological conditions. It delves into the cellular mechanisms underlying hemodynamic coherence, elucidating the roles of the endothelium, glycocalyx, and erythrocytes in sustaining microcirculatory integrity. Furthermore, the review gives comprehensive information about microcirculatory changes observed in cardiac surgery, sepsis, shock, and COVID-19 disease. Through comprehensive exploration, the review underscores the intricate relationship between microcirculation, disease states, and clinical outcomes, emphasizing the importance of understanding and monitoring microvascular dynamics in critical care settings. Full article
(This article belongs to the Section Intensive Care)
Show Figures

Figure 1

Figure 1
<p>Structural and functional relations within the glycocalyx, endothelium, and erythrocytes. Green, pink and gray bars show the anchor components of glycocalyx.</p>
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<p>Effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on vascular endothelial cells (ACE-2 receptor: Angiotensin converting enzyme-2 receptor).</p>
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