bluuebunny/crossref_metadata_2025 huggingface dataset:
Boundary Value Problem for Impulsive Delay Fractional Differential Equations with Several Generalized Proportional Caputo Fractional Derivatives
Authors: Agarwal Ravi P. , Hristova Snezhana
Published: May 2023

A scalar nonlinear impulsive differential equation with a delay and generalized proportional Caputo fractional derivatives (IDGFDE) is investigated. The linear boundary value problem (BVP) for the given fractional differential equation is set up. The explicit form of the unique solution of BVP in the special linear case is obtained. This formula is a generalization of the explicit solution of the case without any delay as well as the case of Caputo fractional derivatives. Furthermore, this integral form of the solution is used to define a special proportional fractional integral operator applied to the determination of a mild solution of the studied BVP for IDGFDE. The relation between the defined mild solution and the solution of the BVP for the IDGFDE is discussed. The existence and uniqueness results for BVP for IDGFDE are proven. The obtained results in this paper are a generalization of several known results.
Genetic Diversification of Starch Branching Enzymes during Maize Domestication and Improvement
Authors: Li Qi , Yang Tiantian , Rui Wenye , Wang Houmiao , Wang Yunyun , Yang Zefeng , Xu Chenwu , Li Pengcheng
Published: May 2023

Elucidating the genetic basis of starch pasting and gelatinization properties is crucial for enhancing the quality of maize and its utility as feed and industrial raw material. In maize, ZmSBE genes encode important starch branching enzymes in the starch biosynthesis pathway. In this study, we re-sequenced the genomic sequences of ZmSBEI, ZmSBEIIa, ZmSBEIIb, and ZmSBEIII in three lines called 335 inbred lines, 68 landrace lines, and 32 teosinte lines. Analyses of nucleotide polymorphisms and haplotype diversity revealed differences in the selection patterns of ZmSBEI, ZmSBEIIa, ZmSBEIIb, and ZmSBEIII during maize domestication and improvement. A marker–trait association analysis of inbred lines detected 22 significant loci, including 18 SNPs and 4 indels significantly associated with three maize starch physicochemical properties. The allele frequencies of two variants (SNP17249C and SNP5055G) were examined in three lines. The frequency of SNP17249C in ZmSBEIIb was highest in teosinte lines, followed by landrace lines, and inbred lines, whereas there were no significant differences in the frequency of SNP5055G in ZmSBEIII among the three lines. These results suggest that ZmSBE genes play an important role in the phenotypic variations in the starch physicochemical properties in maize. The genetic variants detected in this study may be used to develop functional markers for improving maize starch quality.
Aerial Image-Based Documentation and Monitoring of Illegal Archaeological Excavations
Authors: Abate Dante , Faka Marina , Keleshis Christos , Constantinides Christos , Leonidou Andreas , Papageorgiou Andreani
Published: May 2023

The loss of archaeological heritage continues today, because of both natural disasters and human-made actions. Alarmingly, a significant amount of the destruction is perpetrated by looters and illegal excavations. This problem is not a new one. However, it has increased exponentially in recent years, especially in countries which witnessed internal turmoil (i.e., the Arab Spring) but also throughout Europe. Local authorities struggle to provide adequate controls because of a lack of human resources, budget constraints or technological know-how. This paper describes a multimodal documentation and monitoring workflow applied to an archaeological site for which, due to the sensitivity of the topic, no specific details can be publicly disclosed. The techniques used include UAV aerial surveys, image-based modelling, change detection, relief visualization and GIS mapping. Thanks to the analysis of the multitemporal datasets, it was possible to assess the extension and spatial progression of illegal excavation over a two-year period.
Genetic Characterization of the Norwegian Apple Collection
Authors: Gilpin Liv , Røen Dag , Schubert Marian , Davik Jahn , Rumpunen Kimmo , Gardli Kristina Alme , Hjeltnes Stein Harald , Alsheikh Muath
Published: May 2023

Commercial fruit production in Norway is located at around latitude 60° north, demanding a careful choice of adapted cultivars. The most comprehensive collection of apple genetic resources in Norway is being kept in the Norwegian Apple Collection (NAC) at the Njøs Fruit and Berry Centre (NJØS). The collection contains around 350 accessions and was recently genotyped with a single nucleotide polymorphism (SNP) array. Curated SNP data were used for the assessment of structure and diversity, pedigree confirmation, and core collection development. In the following SNP analysis, we identified several duplicates and parent-child relationships. Across the geographic regions represented, the collection was equally diverse. Different methods for analyzing population structure were applied. K-means clustering and a Bayesian modeling approach with prior assumptions of the data revealed five subpopulations associated with geographic breeding centers. The collection has a distinct genetic structure and low relatedness among the accessions; hence, two core collections with 100 accessions in each were created. These new core collections will allow breeders and researchers to use the NAC efficiently. The results from this study suggest that several of the accessions in the Norwegian Apple Collection could be of high importance for breeding purposes.
Positive Status Disclosure and Sexual Risk Behavior Changes among People Living with HIV in the Northern Region of Ghana
Authors: Kabriku Peter Claver , Ansah Edward Wilson , Hagan John Elvis
Published: May 2023

Objective: To investigate sexual behavior changes adopted by People Living with Human Immunodeficiency Virus (PLHIV) on Antiretroviral therapy (ART) in the Northern Region of Ghana. Methods: We employed a cross-sectional survey with a questionnaire to collect data from 900 clients from 9 major ART centers within the region. Chi-square and logistic regression analyses were applied to the data. Results: More than 50% of PLHIV on ART use condoms, reduce sexual partners, practice abstinence, reduce unprotected sex with married/regular partners, and avoid casual sex. Fear of others getting to know patients’ HIV-positive status (χ2 = 7.916, p = 0.005), stigma (χ2 = 5.201, p = 0.023), and fear of loss of family support (χ2 = 4.211, p = 0.040) significantly predict non-disclosure of HIV-positive status among the participants. Change in sexual behavior is influenced by the following: “to avoid spreading the disease to others” (R2 = 0.043, F (1, 898) = 40.237, p < 0.0005), “to avoid contracting other STIs” (R2 = 0.010, F (1, 898) = 8.937, p < 0.0005), “to live long” (R2 = 0.038, F (1, 898) = 35.816, p < 0.0005), “to hide HIV-positive status” (R2 = 0.038, F (1, 898) = 35.587, p < 0.0005), “to achieve good results from ART treatment” (R2 = 0.005, F (1, 898) = 4. 282, p < 0.05), and “to live a Godly life” (R2 = 0.023, F (1, 898) = 20. 880, p < 0.0005). Conclusions: High self-disclosure rate of HIV-positive status was identified, with participants disclosing to their spouses or parents. Reasons for disclosure and non-disclosure differed from person to person.
Effects of Different Teaching Approaches on Proxy Measures of Physical Fitness of Italian Kindergarten Children
Authors: Tortella Patrizia , Quinto Antonella , Fumagalli Guido Francesco , Lipoma Mario , Stodden David , Sgrò Francesco
Published: May 2023

Developing physical fitness (PF) behaviors early in life enhances physical development and facilitates sustained participation in physical activity and sports across childhood. This study addressed the effect of different teaching approaches on precursors of PF in kindergarten children. A total of 178 children (5.45 ± 0.40 years, female = 92) from 11 classes were organized into three groups. Group 1 (structured activity + free play) and Group 2 (only free play) attended the same playground (PrimoSport0246) for one hour/week for 10 weeks. Group 3 (structured activity + free play in kindergarten) followed their standard physical education curriculum at school. PF tests (standing long jump, medicine ball throw, and 20 m running speed) were administered pre- and post-intervention. Factorial ANOVA was implemented using a percentage change in PF performance (PFC) as the dependent variable, and teaching approaches, gender, and age as factors. Group 1 demonstrated significant improvements in fitness performance compared with Groups 2 and 3. Moderate to large effect sizes (Cohen’s d range: 0.68–1.40) were noted in both males and females. Six-year-old demonstrated the greatest improvement in composite PFC compared to Groups 2 and 3. A structured teaching plan, even with a limited dose of once per week, supported the development of PF attributes in kindergarteners.
Physical Rehabilitation of Motor Functional Neurological Disorders: A Narrative Review
Authors: Kelmanson Ayelet N. , Kalichman Leonid , Treger Iuly
Published: May 2023

Functional Neurological Disorders (FNDs) are one of the most common and disabling neurological disorders, affecting approximately 10–30% of patients in neurology clinics. FNDs manifest as a range of motor, sensory, and cognitive symptoms that are not explained by organic disease. This narrative review aims to assess the current state of knowledge in physical-based rehabilitation for motor/movement FNDs in the adult population, with the goal of improving research and medical care for this patient population. To ensure optimal outcomes for patients, it is critical to consider several domains pertaining to FNDs, including which field of discipline they should belong to, how to investigate and test, methods for rating outcome measures, and optimal courses of treatment. In the past, FNDs were primarily treated with psychiatric and psychological interventions. However, recent literature supports the inclusion of physical rehabilitation in the treatment of FNDs. Specifically, physical-based approaches tailored to FNDs have shown promising results. This review utilized a comprehensive search of multiple databases and inclusion criteria to identify relevant studies.
Continuous Vital Signs Monitoring with a Wireless Device on a General Ward: A Survey to Explore Nurses’ Experiences in a Post-Implementation Period
Authors: Becking-Verhaar Femke L. , Verweij Robin P. H. , de Vries Marjan , Vermeulen Hester , van Goor Harry , Huisman-de Waal Getty J.
Published: May 2023

Background: Nurse engagement, perceived need and usefulness affect healthcare technology use, acceptance and improvements in quality, safety and accessibility of healthcare. Nurses’ opinions regarding continuous monitoring appear to be positive. However, facilitators and barriers were little studied. This study explored nurses’ post-implementation experiences of the facilitators and barriers to continuously monitoring patients’ vital signs using a wireless device on general hospital wards. Methods: This study employed a cross-sectional survey. Vocational and registered nurses from three general wards in a Dutch tertiary university hospital participated in a survey comprising open and closed questions. The data were analysed using thematic analysis and descriptive statistics. Results: Fifty-eight nurses (51.3%) completed the survey. Barriers and facilitators were identified under four key themes: (1) timely signalling and early action, (2) time savings and time consumption, (3) patient comfort and satisfaction and (4) preconditions. Conclusions: According to nurses, early detection and intervention for deteriorating patients facilitate the use and acceptance of continuously monitoring vital signs. Barriers primarily concern difficulties connecting patients correctly to the devices and system.
The Effect of Fangcang Shelter Hospitals under Resource Constraints on the Spread of Epidemics
Authors: Li Guangyu , Du Haifeng , Fan Jiarui , He Xiaochen , Wang Wenhua
Published: May 2023

Since the outbreak of the COVID-19 pandemic, Fangcang shelter hospitals have been built and operated in several cities, and have played a huge role in epidemic prevention and control. How to use medical resources effectively in order to maximize epidemic prevention and control is a big challenge that the government should address. In this paper, a two-stage infectious disease model was developed to analyze the role of Fangcang shelter hospitals in epidemic prevention and control, and examine the impact of medical resources allocation on epidemic prevention and control. Our model suggested that the Fangcang shelter hospital could effectively control the rapid spread of the epidemic, and for a very large city with a population of about 10 million and a relative shortage of medical resources, the model predicted that the final number of confirmed cases could be only 3.4% of the total population in the best case scenario. The paper further discusses the optimal solutions regarding medical resource allocation when medical resources are either limited or abundant. The results show that the optimal allocation ratio of resources between designated hospitals and Fangcang shelter hospitals varies with the amount of additional resources. When resources are relatively sufficient, the upper limit of the proportion of makeshift hospitals is about 91%, while the lower limit decreases with the increase in resources. Meanwhile, there is a negative correlation between the intensity of medical work and the proportion of distribution. Our work deepens our understanding of the role of Fangcang shelter hospitals in the pandemic and provides a reference for feasible strategies by which to contain the pandemic.
Detecting Orthostatic Intolerance in Long COVID in a Clinic Setting
Authors: Isaac Robert , Corrado Joanna , Sivan Manoj
Published: May 2023

Introduction: A likely mechanism of Long COVID (LC) is dysautonomia, manifesting as orthostatic intolerance (OI). In our LC service, all patients underwent a National Aeronautics and Space Administration (NASA) Lean Test (NLT), which can detect OI syndromes of Postural Tachycardia Syndrome (PoTS) or Orthostatic Hypotension (OH) in a clinic setting. Patients also completed the COVID-19 Yorkshire Rehabilitation Scale (C19-YRS), a validated LC outcome measure. Our objectives in this retrospective study were (1) to report on the findings of the NLT; and (2) to compare findings from the NLT with LC symptoms reported on the C19-YRS. Methods: NLT data, including maximum heart rate increase, blood pressure decrease, number of minutes completed and symptoms experienced during the NLT were extracted retrospectively, together with palpitation and dizziness scores from the C19-YRS. Mann-Witney U tests were used to examine for statistical difference in palpitation or dizziness scores between patients with normal NLT and those with abnormal NLT. Spearman’s rank was used to examine the correlation between the degree of postural HR and BP change with C19-YRS symptom severity score. Results: Of the 100 patients with LC recruited, 38 experienced symptoms of OI during the NLT; 13 met the haemodynamic screening criteria for PoTS and 9 for OH. On the C19-YRS, 81 reported dizziness as at least a mild problem, and 68 for palpitations being at least a mild problem. There was no significant statistical difference between reported dizziness or palpitation scores in those with normal NLT and those with abnormal NLT. The correlation between symptom severity score and NLT findings was <0.16 (poor). Conclusions: We have found evidence of OI, both symptomatically and haemodynamically in patients with LC. The severity of palpitations and dizziness reported on the C19-YRS does not appear to correlate with NLT findings. We would recommend using the NLT in all LC patients in a clinic setting, regardless of presenting LC symptoms, due to this inconsistency.
Combined Effects of Multiple Per- and Polyfluoroalkyl Substances Exposure on Allostatic Load Using Bayesian Kernel Machine Regression
Authors: Bashir Tahir , Obeng-Gyasi Emmanuel
Published: May 2023

This study aims to investigate the combined effects of per- and polyfluoroalkyl substances (PFAS) on allostatic load, an index of chronic stress that is linked to several chronic diseases, including cardiovascular disease and cancer. Using data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014, this study examines the relationship between six PFAS variables (PFDE, PFNA, PFOS, PFUA, PFOA, and PFHS) and allostatic load using Bayesian Kernel Machine Regression (BKMR) analysis. The study also investigates the impact of individual and combined PFAS exposure on allostatic load using various exposure-response relationships, such as univariate, bivariate, or multivariate models. The analysis reveals that the combined exposure to PFDE, PFNA, and PFUA had the most significant positive trend with allostatic load when it was modeled as a binary variable, while PFDE, PFOS, and PFNA had the most significant positive trend with allostatic load when modeled as a continuous variable. These findings provide valuable insight into the consequences of cumulative exposure to multiple PFAS on allostatic load, which can help public health practitioners identify the dangers associated with potential combined exposure to select PFAS of interest. In summary, this study highlights the critical role of PFAS exposure in chronic stress-related diseases and emphasizes the need for effective strategies to minimize exposure to these chemicals to reduce the risk of chronic diseases. It underscores the importance of considering the combined effects of PFAS when assessing their impact on human health and offers valuable information for policymakers and regulators to develop strategies to protect public health.
Correction: Starker et al. Intention for Screening Colonoscopy among Previous Non-Participants: Results of a Representative Cross-Sectional Study in Germany. Int. J. Environ. Res. Public Health 2021, 18, 4160
Authors: Starker Anne , Prütz Franziska , Jordan Susanne
Published: May 2023

In the published publication [...]
The Artificial Intelligence in Teledermatology: A Narrative Review on Opportunities, Perspectives, and Bottlenecks
Authors: Giansanti Daniele
Published: May 2023

Artificial intelligence (AI) is recently seeing significant advances in teledermatology (TD), also thanks to the developments that have taken place during the COVID-19 pandemic. In the last two years, there was an important development of studies that focused on opportunities, perspectives, and problems in this field. The topic is very important because the telemedicine and AI applied to dermatology have the opportunity to improve both the quality of healthcare for citizens and the workflow of healthcare professionals. This study conducted an overview on the opportunities, the perspectives, and the problems related to the integration of TD with AI. The methodology of this review, following a standardized checklist, was based on: (I) a search of PubMed and Scopus and (II) an eligibility assessment, using parameters with five levels of score. The outcome highlighted that applications of this integration have been identified in various skin pathologies and in quality control, both in eHealth and mHealth. Many of these applications are based on Apps used by citizens in mHealth for self-care with new opportunities but also open questions. A generalized enthusiasm has been registered regarding the opportunities and general perspectives on improving the quality of care, optimizing the healthcare processes, minimizing costs, reducing the stress in the healthcare facilities, and in making citizens, now at the center, more satisfied. However, critical issues have emerged related to: (a) the need to improve the process of diffusion of the Apps in the hands of citizens, with better design, validation, standardization, and cybersecurity; (b) the need for better attention paid to medico-legal and ethical issues; and (c) the need for the stabilization of international and national regulations. Targeted agreement initiatives, such as position statements, guidelines, and/or consensus initiatives, are needed to ensure a better result for all, along with the design of both specific plans and shared workflows.
Applications and Opportunities in Using Disulfides, Thiosulfinates, and Thiosulfonates as Antibacterials
Authors: Blume Lindsay , Long Timothy E. , Turos Edward
Published: May 2023

Sulfur-containing molecules have a long history of bioactivity, especially as antibacterial agents in the fight against infectious pathogens. Organosulfur compounds from natural products have been used to treat infections throughout history. Many commercially available antibiotics also have sulfur-based moieties in their structural backbones. In the following review, we summarize sulfur-containing antibacterial compounds, focusing on disulfides, thiosulfinates, and thiosulfonates, and opportunities for future developments in the field.
Identification of Potential Biomarkers for Diagnosis of Patients with Methamphetamine Use Disorder
Authors: Jang Won-Jun , Song Sang-Hoon , Son Taekwon , Bae Jung Woo , Lee Sooyeun , Jeong Chul-Ho
Published: May 2023

The current method for diagnosing methamphetamine use disorder (MUD) relies on self-reports and interviews with psychiatrists, which lack scientific rigor. This highlights the need for novel biomarkers to accurately diagnose MUD. In this study, we identified transcriptome biomarkers using hair follicles and proposed a diagnostic model for monitoring the MUD treatment process. We performed RNA sequencing analysis on hair follicle cells from healthy controls and former and current MUD patients who had been detained in the past for illegal use of methamphetamine (MA). We selected candidate genes for monitoring MUD patients by performing multivariate analysis methods, such as PCA and PLS-DA, and PPI network analysis. We developed a two-stage diagnostic model using multivariate ROC analysis based on the PLS-DA method. We constructed a two-step prediction model for MUD diagnosis using multivariate ROC analysis, including 10 biomarkers. The first step model, which distinguishes non-recovered patients from others, showed very high accuracy (prediction accuracy, 98.7%). The second step model, which distinguishes almost-recovered patients from healthy controls, showed high accuracy (prediction accuracy, 81.3%). This study is the first report to use hair follicles of MUD patients and to develop a MUD prediction model based on transcriptomic biomarkers, which offers a potential solution to improve the accuracy of MUD diagnosis and may lead to the development of better pharmacological treatments for the disorder in the future.
Design, Synthesis and Antitumor Activity of 1H-indazole-3-amine Derivatives
Authors: Wang Congyu , Zhu Mei , Long Xuesha , Wang Qin , Wang Zhenchao , Ouyang Guiping
Published: May 2023

A series of indazole derivatives were designed and synthesized by molecular hybridization strategy, and these compounds were evaluated the inhibitory activities against human cancer cell lines of lung (A549), chronic myeloid leukemia (K562), prostate (PC-3), and hepatoma (Hep-G2) by methyl thiazolyl tetrazolium (MTT) colorimetric assay. Among these, compound 6o exhibited a promising inhibitory effect against the K562 cell line with the IC50 (50% inhibition concentration) value of 5.15 µM, and this compound showed great selectivity for normal cell (HEK-293, IC50 = 33.2 µM). Moreover, compound 6o was confirmed to affect apoptosis and cell cycle possibly by inhibiting Bcl2 family members and the p53/MDM2 pathway in a concentration-dependent manner. Overall, this study indicates that compound 6o could be a promising scaffold to develop an effective and low-toxic anticancer agent.
Sleep Paralysis and Lucid Dreaming—Between Waking and Dreaming: A Review about Two Extraordinary States
Authors: Ableidinger Severin , Holzinger Brigitte
Published: May 2023

Background: Sleep paralysis and lucid dreams are two states of consciousness that are connected to REM sleep but are defined by higher awareness in contrast to regular REM sleep. Despite these similarities, the two states differ widely in their emotional tone and their perceived controllability. This review aims to summarize the current research containing sleep paralysis and lucid dreams. However, given the sparsity of the research, one single topic cannot be chosen. Methods: Articles containing both lucid dreams as well as sleep paralysis were searched for in the following databanks: MEDLINE, Scopus, Web of Science, PsycInfo, PsycArticles, and PSYNDEX. Further, citations of the found papers were examined. Results: 10 studies were included in the review. Most of the studies were surveys, but there was also a case study, a randomized trial, and an observational EEG study. The numbers of participants ranged from a single participant in the case study to 1928 participants in a survey. The main findings were that correlations between sleep paralysis and lucid dreaming were positive and significant in most of the studies. Conclusions: There is a connection between lucid dreaming and sleep paralysis. However, research is still very limited and diverse in the methodologies used. Future research should build standardized methods for examining the two phenomena.
Multispectral Satellite Image Analysis for Computing Vegetation Indices by R in the Khartoum Region of Sudan, Northeast Africa
Authors: Lemenkova Polina , Debeir Olivier
Published: May 2023

Desertification is one of the most destructive climate-related issues in the Sudan–Sahel region of Africa. As the assessment of desertification is possible by satellite image analysis using vegetation indices (VIs), this study reports on the technical advantages and capabilities of scripting the ‘raster’ and ‘terra’ R-language packages for computing the VIs. The test area which was considered includes the region of the confluence between the Blue and White Niles in Khartoum, southern Sudan, northeast Africa and the Landsat 8–9 OLI/TIRS images taken for the years 2013, 2018 and 2022, which were chosen as test datasets. The VIs used here are robust indicators of plant greenness, and combined with vegetation coverage, are essential parameters for environmental analytics. Five VIs were calculated to compare both the status and dynamics of vegetation through the differences between the images collected within the nine-year span. Using scripts for computing and visualising the VIs over Sudan demonstrates previously unreported patterns of vegetation to reveal climate–vegetation relationships. The ability of the R packages ‘raster’ and ‘terra’ to process spatial data was enhanced through scripting to automate image analysis and mapping, and choosing Sudan for the case study enables us to present new perspectives for image processing.
The Impact of Regional Integration Strategies on the Formation of City Regions and Its Agglomeration Shadow: Evidence from the Yangtze River Delta, China
Authors: Zhen Yanlin , Shi Dehao , Lu Yanan
Published: May 2023

Using a sample of 122 county-level units in the Yangtze River Delta (YRD) region from 2000 to 2017, this study employs a difference-in-differences model (DID) to examine the impact of regional integration strategy (RIS) on city-region formation and a difference-in-difference-in-difference model (DDD) to test whether it has spatial heterogeneity. The results indicate that RIS has a significant positive impact on industrial integration while it also displays obvious industrial heterogeneity and spatial heterogeneity. The results of the present study contribute to the following points: First, the implementation of RIS promotes a balanced layout of the secondary industry in the region, yet the tertiary industry tends to agglomerate towards central cities. Furthermore, we found that RIS has a more significant negative effect on the integration of the secondary industry and tertiary industry in cities adjacent to metropolis. Consequently, RIS magnifies the “agglomeration shadow” within city regions in terms of industrial integration. Last, our in-depth fieldwork on Jiaxing unravels the mechanism of the shadow effect of RIS.
Plasmonic Nanodomains Decorated on Two-Dimensional Oxide Semiconductors for Photonic-Assisted CO2 Conversion
Authors: Karbalaei Akbari Mohammad , Siraj Lopa Nasrin , Park Jihae , Zhuiykov Serge
Published: May 2023

Plasmonic nanostructures ensure the reception and harvesting of visible lights for novel photonic applications. In this area, plasmonic crystalline nanodomains decorated on the surface of two-dimensional (2D) semiconductor materials represent a new class of hybrid nanostructures. These plasmonic nanodomains activate supplementary mechanisms at material heterointerfaces, enabling the transfer of photogenerated charge carriers from plasmonic antennae into adjacent 2D semiconductors and therefore activate a wide range of visible-light assisted applications. Here, the controlled growth of crystalline plasmonic nanodomains on 2D Ga2O3 nanosheets was achieved by sonochemical-assisted synthesis. In this technique, Ag and Se nanodomains grew on 2D surface oxide films of gallium-based alloy. The multiple contribution of plasmonic nanodomains enabled the visible-light-assisted hot-electron generation at 2D plasmonic hybrid interfaces, and therefore considerably altered the photonic properties of the 2D Ga2O3 nanosheets. Specifically, the multiple contribution of semiconductor–plasmonic hybrid 2D heterointerfaces enabled efficient CO2 conversion through combined photocatalysis and triboelectric-activated catalysis. The solar-powered acoustic-activated conversion approach of the present study enabled us to achieve the CO2 conversion efficiency of more than 94% in the reaction chambers containing 2D Ga2O3-Ag nanosheets.
Recent Advances in Electrospun Membranes for Radiative Cooling
Authors: Zhang Dongxue , Zhang Haiyan , Xu Zhiguang , Zhao Yan
Published: May 2023

Radiative cooling is an approach that maximizes the thermal emission through the atmospheric window in order to dissipate heat, while minimizing the absorption of incoming atmospheric radiation, to realize a net cooling effect without consuming energy. Electrospun membranes are made of ultra-thin fibers with high porosity and surface area, which makes them suitable for radiative cooling applications. Many studies have investigated the use of electrospun membranes for radiative cooling, but a comprehensive review that summarizes the research progress in this area is still lacking. In this review, we first summarize the basic principles of radiative cooling and its significance in achieving sustainable cooling. We then introduce the concept of radiative cooling of electrospun membranes and discuss the selection criteria for materials. Furthermore, we examine recent advancements in the structural design of electrospun membranes for improved cooling performance, including optimization of geometric parameters, incorporation of highly reflective nanoparticles, and designing multilayer structure. Additionally, we discuss dual-mode temperature regulation, which aims to adapt to a wider range of temperature conditions. Finally, we provide perspectives for the development of electrospun membranes for efficient radiative cooling. This review will provide a valuable resource for researchers working in the field of radiative cooling, as well as for engineers and designers interested in commercializing and developing new applications for these materials.
Techno-Economic Analysis and Life Cycle Assessment of High-Velocity Oxy-Fuel Technology Compared to Chromium Electrodeposition
Authors: Merlo Antoine , Duminica Florin , Daniel Alain , Léonard Grégoire
Published: May 2023

Due to the toxicity associated with chromium electrodeposition, alternatives to that process are highly sought after. One of those potential alternatives is High Velocity Oxy-Fuel (HVOF). In this work, a HVOF installation is compared with chromium electrodeposition from environmental and economic points of view by using Life Cycle Assessment (LCA) and Techno-Economic Analysis (TEA) for the evaluation. Costs and environmental impacts per piece coated are then evaluated. On an economic side, the lower labor requirements of HVOF allow one to noticeably reduce the costs (20.9% reduction) per functional unit (F.U.). Furthermore, on an environmental side, HVOF has a lower impact for the toxicity compared to electrodeposition, even if the results are a bit more mixed in other impact categories.
Chamber Protection of Zinc with Ethylhexanoic Acid
Authors: Goncharova Olga A. , Luchkin Andrey Yu. , Andreev Nickolay N. , Grafov Oleg Yu. , Makarova Olga S. , Kuznetsov Ilya A. , Vesely Sergey S.
Published: May 2023

Chamber protection is a promising and quickly developing method of vapor-phase protection of metals against atmospheric corrosion by inhibitors. It was shown that chamber treatment with 2-ethylhexanoic acid (EHA) efficiently inhibits the initiation of zinc corrosion. The optimum conditions (temperature and duration) of zinc treatment with vapors of this compound were determined. If these conditions are met, adsorption films of EHA with thicknesses up to 100 nm are formed on the metal surface. It was found that their protective properties increase during the first day as zinc is exposed to air after chamber treatment. The anticorrosive action of adsorption films is due both to the surface being shielded from the corrosive environment and to the inhibition of corrosion processes on the active surface of the metal. Corrosion inhibition was caused by the ability of EHA to convert zinc to the passive state and inhibit its local anionic depassivation.
Experimental Study of Mechanical Properties and Failure Characteristics of Coal–Rock-like Composite Based on 3D Printing Technology
Authors: Chen Ying , Zhang Zikai , Cao Chen , Wang Shuai , Xu Guangyuan , Chen Yang , Liu Jinliang
Published: May 2023

Coal contains cracks and has strong heterogeneity, so the data dispersion is large in laboratory tests. In this study, 3D printing technology is used to simulate hard rock and coal, and the rock mechanics test method is used to carry out the coal–rock combination experiment. The deformation characteristics and failure modes of the combination are analyzed and compared with the relevant parameters of the single body. The results show that the uniaxial compressive strength of the composite sample is inversely proportional to the thickness of the weak body and directly proportional to the thickness of the strong body. The Protodyakonov model or ASTM model can be used as a verification method for the results of a uniaxial compressive strength test of coal–rock combination. The elastic modulus of the combination is the equivalent elastic modulus, and the elastic modulus of the combination is between the elastic modulus of the two constituent monomers, which can be analyzed using the Reuss model. The failure of the composite sample occurs in the low-strength material, while the high-strength section is rebounding as an extra load on the low-strength body, which may cause a sharp increase in the strain rate of the weak body. The main failure mode of the sample with a small height–diameter ratio is splitting, and the failure mode of the sample with a large height–diameter ratio is shear fracturing. When the height–diameter ratio is not greater than 1, it shows pure splitting, and when the height–diameter ratio is 1~2, it shows a mixed mode of splitting and shear fracture. The shape has a significant effect on the uniaxial compressive strength of the composite specimen. For the impact propensity, it can be determined that the uniaxial compressive strength of the combination is higher than that of the single body, and the dynamic failure time is lower than that of the single body. It can hardly determine the elastic energy and the impact energy of the composite with the relationship to the weak body. The proposed methodology provides new cutting-edge test technologies in the study of coal and coal-like materials, with an exploration of their mechanical properties under compression.
Influence of Repair Welding on the Fatigue Behavior of S355J2 T-Joints
Authors: Zhao Peng , Yu Banglong , Wang Ping , Liu Yong , Song Xiaoguo
Published: May 2023

This paper investigated the effect of repair welding on the microstructure, mechanical properties, and high cycle fatigue properties of S355J2 steel T-joints in orthotropic bridge decks. The test results found that the increase in grain size of the coarse, heat-affected zone decreased the hardness of the welded joint by about 30 HV. The tensile strength of the repair-welded joints was reduced by 20 MPa compared to the welded joints. For the high cycle fatigue behavior, the fatigue life of repair-welded joints is lower than that of the welded joints under the same dynamic load. The fracture positions of toe repair-welded joints were all at the weld root, while the fracture positions of the deck repair-welded joints were at the weld toe and weld root, with the same proportion. The fatigue life of toe repair-welded joints is reduced more than that of deck repair-welded joints. The traction structural stress method was used to analyze fatigue data of the welded and repair-welded joints, and the influence of angular misalignment on was considered. The fatigue data with and without AM are all within the ±95% confidence interval of the master S-N curve.
Thermal Programming of Commercially Available Orthodontic NiTi Archwires
Authors: Wichelhaus Andrea , Mehnert Amelie , Stocker Thomas , Baumert Uwe , Mertmann Matthias , Sabbagh Hisham , Seidel Corinna L.
Published: May 2023

The shape of superelastic Nickel-Titanium (NiTi) archwires can be adjusted with thermal treatments using devices such as the Memory-MakerTM (Forestadent), which potentially affects their mechanical properties. The effect of such treatments on these mechanical properties was simulated by means of a laboratory furnace. Fourteen commercially available NiTi wires (0.018″ × 0.025″) were selected from the manufacturers American Orthodontics, Dentaurum, Forestadent, GAC, Ormco, Rocky Mountain Orthodontics and 3M Unitek. Specimens were heat treated using different combinations of annealing duration (1/5/10 min) and annealing temperature (250–800 °C) and investigated using angle measurements and three-point bending tests. Complete shape adaptation was found at distinct annealing durations/temperatures for each wire ranging between ~650–750 °C (1 min), ~550–700 °C (5 min) and ~450–650 °C (10 min), followed by a loss of superelastic properties shortly afterwards at ~750 °C (1 min), ~600–650 °C (5 min) and ~550–600 °C (10 min). Wire-specific working ranges (complete shaping without loss of superelasticity) were defined and a numerical score (e.g., stable forces) was developed for the three-point bending test. Overall, the wires Titanol Superelastic (Forestadent), Tensic (Dentaurum), FLI CuNiTi27 (Rocky Mountain Orthodontics) and Nitinol Classic (3M Unitek) proved to be the most user-friendly. Thermal shape adjustment requires wire-specific working ranges to allow complete shape acceptance and high scores in bending test performance to ensure permanence of the superelastic behaviour.
LCF and HCF of Short Carbon Fibers Reinforced AE42 Mg Alloy
Authors: Alsaleh Naser A. , Ataya Sabbah , Latief Fahamsyah H. , Ahmed Mohamed M. Z. , Ataya Ahmed , Abdul-Latif Akrum
Published: May 2023

Lightweight magnesium alloys and magnesium matrix composites have recently become more widespread for high-efficiency applications, including automobile, aerospace, defense, and electronic industries. Cast magnesium and magnesium matrix composites are applied in many highly moving and rotating parts, these parts can suffer from fatigue loading and are consequently subjected to fatigue failure. Reversed tensile-compression low-cycle fatigue (LCF) and high-cycle fatigue (HCF) of short fibers reinforced and unreinforced AE42 have been studied at temperatures of 20 °C, 150 °C, and 250 °C. To select suitable fatigue testing conditions, tensile tests have been carried out on AE42 and the composite material AE42-C at temperatures of up to 300 °C. The Wohler curves σa (NF) have shown that the fatigue strength of the reinforced AE42-C in the HCF range was double that of unreinforced AE42. In the LCF range at certain strain amplitudes, the fatigue life of the composite materials is much less than that of the matrix alloys, this is due to the low ductility of this composite material. Furthermore, a slight temperature influence up to 150 °C has been established on the fatigue behavior of the AE42-C. The fatigue life curves Δεtotal (NF) were described using the Basquin and Manson–Coffin approaches. Fracture surface investigations showed a mixed mode of serration fatigue pattern on the matrix and carbon fibers fracturing and debonding from the matrix alloy.
Preparation of Waste PP/Fly Ash/Waste Stone Powder Composites and Evaluation of Their Mechanical Properties
Authors: Ge Jun Cong , Lee Eun Seo , Kim Deuk Ju , Kang Ji Ho , Im Ik Tae , Choi Nag Jung
Published: May 2023

The research was carried out to analyze the combined and mechanical properties of polypropylene (PP)/fly ash (FA)/waste stone powder (WSP) composite materials. PP, FA and WSP were mixed and prepared into PP100 (pure PP), PP90 (90 wt% PP + 5 wt% FA + 5 wt% WSP), PP80 (80 wt% PP + 10 wt% FA + 10 wt% WSP), PP70 (70 wt% PP + 15 wt% FA + 15 wt% WSP), PP60 (60 wt% PP + 20 wt% FA + 20 wt% WSP) and PP50 (50 wt% PP + 25 wt% FA + 25 wt% WSP) composite materials using an injection molding machine. The research results indicate that all PP/FA/WSP composite materials can be prepared through the injection molding process and there are no cracks or fractures found on the surface of the composite materials. The research results of thermogravimetric analysis are consistent with expectations, indicating that the preparation method of the composite materials in this study is reliable. Although the addition of FA and WSP powder cannot increase the tensile strength, it is very helpful to improve the bending strength and notched impact energy. Especially for notched impact energy, the addition of FA and WSP results in an increase in the notched impact energy of all PP/FA/WSP composite materials by 14.58–22.22%. This study provides a new direction for the reuse of various waste resources. Moreover, based on the excellent bending strength and notched impact energy, the PP/FA/WSP composite materials have great application potential in the composite plastic industry, artificial stone, floor tiles and other industries in the future.
Fabrication of Electrospun PLA-nHAp Nanocomposite for Sustained Drug Release in Dental and Orthopedic Applications
Authors: Kanak Nishat Anzum , Shahruzzaman Md. , Islam Md. Sazedul , Takafuji Makoto , Rahman Mohammed Mizanur , Kabir Sumaya F.
Published: May 2023

This study describes the fabrication of nanocomposites using electrospinning technique from poly lactic acid (PLA) and nano-hydroxyapatite (n-HAp). The prepared electrospun PLA-nHAP nanocomposite is intended to be used for drug delivery application. A hydrogen bond in between nHAp and PLA was confirmed by Fourier transform infrared (FT-IR) spectroscopy. Degradation study of the prepared electrospun PLA-nHAp nanocomposite was conducted for 30 days both in phosphate buffer solution (PBS) of pH 7.4 and deionized water. The degradation of the nanocomposite occurred faster in PBS in comparison to water. Cytotoxicity analysis was conducted on both Vero cells and BHK-21 cells and the survival percentage of both cells was found to be more than 95%, which indicates that the prepared nanocomposite is non-toxic and biocompatible. Gentamicin was loaded in the nanocomposite via an encapsulation process and the in vitro drug delivery process was investigated in phosphate buffer solution at different pHs. An initial burst release of the drug was observed from the nanocomposite after 1 to 2 weeks for all pH media. After that, a sustained drug release behavior was observed for the nanocomposite for 8 weeks with a release of 80%, 70% and 50% at pHs 5.5, 6.0 and 7.4, respectively. It can be suggested that the electrospun PLA-nHAp nanocomposite can be used as a potential antibacterial drug carrier for sustained drug release in dental and orthopedic sector.
Analytical Study of SH Wave Scattering by a Circular Pipeline in an Inhomogeneous Concrete with Density Variation
Authors: Yang Zailin , Sun Chenxi , Jiang Guanxixi , Song Yunqiu , Li Xinzhu , Yang Yong
Published: May 2023

In this paper, the shear horizontal (SH) wave scattering by a circular pipeline in an inhomogeneous concrete with density variation is studied. A model of inhomogeneous concrete with density variation in the form of a polynomial-exponential coupling function is established. By using the complex function method and conformal transformation, the incident and scattering wave field of SH wave in concrete are obtained, and the analytic expression of dynamic stress concentration factor (DSCF) around the circular pipeline is given. The results show that the inhomogeneous density parameters, the wave number of the incident wave and the angle of the incident wave in concrete are important factors affecting the distribution of dynamic stress around the circular pipe in concrete with inhomogeneous density. The research results can provide a theoretical reference and a basis for analyzing the influence of circular pipeline on elastic wave propagation in an inhomogeneous concrete with density variation.
Faceting/Roughening of WC/Binder Interfaces in Cemented Carbides: A Review
Authors: Straumal Boris B. , Konyashin Igor
Published: May 2023

Hardmetals (or cemented carbides) were invented a hundred years ago and became one of the most important materials in engineering. The unique conjunction of fracture toughness, abrasion resistance and hardness makes WC-Co cemented carbides irreplaceable for numerous applications. As a rule, the WC crystallites in the sintered WC-Co hardmetals are perfectly faceted and possess a truncated trigonal prism shape. However, the so-called faceting–roughening phase transition can force the flat (faceted) surfaces or interfaces to become curved. In this review, we analyze how different factors can influence the (faceted) shape of WC crystallites in the cemented carbides. Among these factors are the modification of fabrication parameters of usual WC-Co cemented carbides; alloying of conventional cobalt binder using various metals; alloying of cobalt binder using nitrides, borides, carbides, silicides, oxides; and substitution of cobalt with other binders, including high entropy alloys (HEAs). The faceting–roughening phase transition of WC/binder interfaces and its influence on the properties of cemented carbides is also discussed. In particular, the increase in the hardness and fracture toughness of cemented carbides correlates with transition of WC crystallites from a faceted to a rounded shape.