bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Research on Properties of UHPC Based on Composite Cementitious Materials System
Authors: Kong Fansheng , Xu Fang , Xiong Qiuyang , Xu Songji , Li Xiang , Fu Wenxiang , Guo Zhijiong
Published: August 2022

As concrete damage occurs frequently in the transition zone of bridge expansion joints, this paper discussed ultra-high-performance concrete (UHPC) based on composite cementitious materials system for the repair of the bridge expansion joint transition zone. The performance of UHPC based on composite cementitious materials system was studied by combining the macroscopic properties and microstructure of the material with the hydration mechanism of the cementitious material. The influence of sulphate aluminum cement (SAC) on composite cementitious materials system was studied. The experimental results showed that the appropriate amount of SAC can effectively reduce the setting time in the composite cementitious materials system. While SAC caused the strength to decrease, it has little effect on the mechanical properties of the composite cementitious materials system. When the ratio of SAC is 0.1 in the composite cementitious materials system, the setting time is shortened with maintaining the dense micro-structure observed by the SEM images. It can achieve fast hardening and have good early mechanical performance while retaining excellent long-term properties. Therefore, the addition of SAC can effectively make it possible to apply the excellent performance of UHPC for the repair of highway and bridge.
Adhesion Strength of Amorphous Carbon Films Deposited on a Trench Sidewall
Authors: Toyoshima Kyohei , Farghali Abdelrahman , Choi Junho
Published: August 2022

Hydrogenated amorphous carbon (a-C:H) films were deposited on the sidewall of 3-mm-wide stainless steel or Si trench, and the adhesion strength of the films was evaluated using a micro-scratch tester. Particularly, the effects of carbon ion implantation and Si-containing interlayer (a-SiCx:H) as the pretreatments on the adhesion strength of the a-C:H films prepared on the trench sidewall were investigated. It was found that both carbon ion implantation and interlayer improved the adhesion strength of the a-C:H films deposited on the trench sidewalls. In addition, the carbon ion implantation dominated the adhesion strength of the a-C:H films for the Si substrates, and the interlayer for the stainless steel substrates. In the case of the stainless steel substrates, the carbon was accumulated on the surface of the trench sidewall instead of implantation, whereas the carbon ions were implanted to the Si substrates on the trench sidewall to form a mixing layer. The a-SiCx:H interlayer forms Fe–Si bonds between the stainless steel substrate and the interlayer, which is thought to improve the adhesion strength. It was also found that there is a negative correlation between the trench depth and the adhesion strength regardless of the pretreatment methods.
Fatigue and Life Prediction of S135 High-Strength Drill Pipe Steel under Tension–Torsion Multiaxial Loading
Authors: Luo Sheji , Liu Ming , Han Lihong , Xue Yuna
Published: August 2022

This paper investigates the fatigue behavior of S135 high-strength drill pipe steel under tension–torsion multiaxial loading. Based on the concept of critical plane during fatigue, the fatigue model under the combined loading of tension–torsion is established. The proposed model is validated, and the predicted results are in good agreement with the experimental testing results. The maximum relative errors between the estimation and the experiment are mostly within the range of factor two to three for proportional, and 90° non-proportional tension–torsion loading. Meanwhile, the failure mechanism is also discussed through fracture analysis.
Characterization and Wear Behaviors of Electrodeposited Ni-MoS2/SiC Composite Coating
Authors: Yan Yutao , Lu Lifeng , Huo Yuqiu , Zhao Yong
Published: August 2022

Among the preparation methods of functional coatings, the electrodeposition technique has attracted much attention due to its advantages of economy, high efficiency and good structural adaptability. The application of aluminum alloy materials is greatly limited due to their poor friction reduction and wear resistance. Therefore, to enhance the tribological behaviors of aluminum alloy materials, the Ni-MoS2, Ni-SiC and Ni-MoS2/SiC composite coatings were prepared on the 2218 aluminum alloy by an electrodeposition technique. The prepared composite coating samples exhibited a compact and dense microstructure, which was consistent with the result of their high microhardness. No obvious microcracks and defects appeared at the interfaces, indicating that the composite coating samples had good adhesion to the substrates and can effectively improve the frictional shear resistance. The results of wear experiment showed that the wear rate, friction coefficient and friction response time of all composite coating samples were lower than that of the substrate sample. However, the friction reduction and wear resistance of the same composite coating sample were not consistent. The friction coefficient of the Ni-MoS2 composite coating sample was the lowest, and the wear rate of the Ni-SiC composite coating sample was the lowest. According to the worn surface observations, the wear mechanism of composite coating samples was mainly characterized by the mild abrasive wear, flake spalling, tearing and pits caused by particle shedding, and the substrate sample showed a severe adhesive wear and abrasive wear.
Resonant Tunneling of Electrons and Holes through the InxGa1−xN/GaN Parabolic Quantum Well/LED Structure
Authors: Althib Hind
Published: August 2022

Models describing the tunneling of electrons and holes through parabolic InxGa1−xN/GaN quantum well/LED structures with respect to strain were developed. The transmission coefficient, tunneling lifetime, and efficiency of LED structures were evaluated by solving the Schrödinger equation. The effects of the mole fraction on the structure strain, resonant tunneling and tunneling lifetime, and LH–HH splitting were characterized. The value of LH–HH splitting increased and remained higher than the Fermi energy; therefore, only the HH band was dominant in terms of the valence band properties. The results indicate that an increase in the mole fraction can lead to efficiency droop.
Optical AR Coatings of the Mid-IR Band for ZnGeP2 Single Crystals Based on ZnS and Oxide Aluminum
Authors: Zinoviev Mikhail , Yudin Nikolai Nikolayevich , Podzvalov Sergey , Slyunko Elena , Yudin Nikolai Aleksandrovich , Kulesh Maksim , Dorofeev Igor , Baalbaki Houssain
Published: August 2022

In this work, the parameters of antireflection interference coatings based on alternating layers of ZnS/Al2O3 on the laser-induced damage threshold (LIDT) of ZGP crystals under the action of Ho:YAG laser radiation at a wavelength of 2.097 μm were determined. The coating deposition was carried out using the ion-beam sputtering method. The LIDT of the sample with a coating based on alternating layers ZnS and Al2O3 was equal to WoE = 3.45 J/cm2, and the LIDT of the uncoated sample was equal to WoE = 2.23 J/cm2. An increase in the optical breakdown threshold by ~55% was observed after the deposition of an AR coating based on ZnS and Al2O3 materials. An assumption was made about the absence of local fluctuations in the composition and mechanical stresses in the case of the coated sample, namely that this leads to good adhesion of the multilayer coating to the polished surface of the crystal, and as a result to an increase in the optical breakdown threshold as compared to the uncoated sample due to closure of the dangling chemical bonds and bulk defects emerging on the polished surface.
A Tunable Zig-Zag Reflective Elastic Metasurface
Authors: Xu Zhu-Long , Yu Shi-Bo , Liu Junjie , Chuang Kuo-Chih
Published: August 2022

In this paper, inspired by origami structures, we offer a very simple tuning method to overcome the limitations of general elastic metasurfaces, where only a certain functionality at a certain frequency range can be achieved, by designing a reflective metasurface based on foldable/deployable zig-zag structures. By utilizing peg/screw connections, the folding angles of the zig-zag structures can be easily tuned while also being fixable. By tuning the folding angle, the subunit of the zig-zag metasurface can cover a 2π phase shift span and the phase shift can be tuned continuously, and almost linearly, with respect to the folding angle. With a simple folding motion, the tunable reflective metasurface can steer reflected flexural waves in different directions and focus-reflected flexural waves with different focal distances. In addition to demonstrating tunable performance, the mechanism that associates the changing speed of the phase shift is explained. The proposed tunable zig-zag elastic metasurface provides a new way to design reconfigurable metamaterials/metasurfaces.
Barium Hydroxide Nanoparticle–Phosphoric Acid System for Desalination and Consolidation of Tomb Murals
Authors: Rong Yan , Yang Jinglong , Huang Siping , Li Yuhu
Published: August 2022

Tomb murals are an important component of cultural heritage, but the extant majority of burial murals are severely damaged. There are various causes behind the deterioration of tomb murals, among which the detrimental effects of sodium sulfate on murals are some of the most difficult to treat. In the past decades, the application of alkaline earth metal hydroxides (such as Ba(OH)2, Ca(OH)2, and Ma(OH)2) for the conservation and consolidation of murals has become more common. However, there are some problems, such as large particles, poor permeability, and potential for surface whitening. In response to this issue, we investigated a facile method for the synthesis of nano barium hydroxide (N-Ba(OH)2), from which we developed a barium hydroxide nanoparticle–phosphoric acid (N-Ba(OH)2/H3PO4) multisite in situ consolidation system. The results show that N-Ba(OH)2/H3PO4 consolidation material has good permeability and mechanical properties compared with commercial Ba(OH)2 and other common consolidation materials. This material performs very well in both salt resistance and desalination tests, the color difference change is minimal, and the technique is suitable for the practical manipulation of outdoor artifact conservation work. Recently, it has even been used in the desalination and consolidation of tomb murals in Jiangxi, China, the results of which opened a new way of thinking about the long-term conservation of tomb murals.
Using Global Red List Data to Inform Localised Research and Conservation Priorities—A Case Study in the Republic of Seychelles
Authors: Bullock Robert W. , Grimmel Henriette M. V. , Moulinie Ellie E. , Pouponeau Dillys K. , Lea James S. E.
Published: August 2022

Global Red List assessments are powerful tools for informing large-scale conservation decision-making processes, however, they can also be used to inform more localised research and conservation priorities. Here, a conservation status assessment was conducted for the marine vertebrate biodiversity of two recently designated marine protected areas in the Republic of Seychelles. International Union for Conservation of Nature (IUCN) Red List assessments were compiled and trends in data analysed for the 524 species recorded locally. Findings suggest that 5.5–23.1% of all marine vertebrate biodiversity at the site is threatened or near-threatened with extinction (combined as ‘elevated risk’), and highlights sharks and rays as contributing two thirds (67.9%) to the ‘elevated risk’ biodiversity of the site. Fishing activities constitute the largest threat to every ‘elevated risk’ species using the site, with sharks and rays being most impacted. Species richness analysis across major habitat types evidence the high value of coral reef areas to almost all species and the importance of adjacent deep-water areas for ‘elevated risk’ species. Theoretical national assessments showed that the majority of globally ER species remained in the same Red List category in their respective national assessment. This study demonstrates the value of global Red List data for optimising research efforts and conservation practices on a localised scale and for informing the design and zonation of marine protected areas.
The Relationship between Population Density and Body Size of the Giant Mountain Crab Indochinamon bhumibol (Naiyanetr, 2001), an Endangered Species of Freshwater Crab from Northeastern Thailand (Potamoidea: Potamidae)
Authors: Sripho Sirikorn , Chaiyarat Rattanawat
Published: August 2022

The giant mountain crab (Indochinamon bhumibol) is endemic to Loei Province in north-eastern Thailand. Although, little knowledge is available on the factors affecting population dynamics and individual fitness. This study aimed to investigate the relationship between the population density and body size of the crab. The mark–recapture method was conducted in Phu Ruea National Park (PR, small area) and Phu Luang Wildlife Sanctuary (PL, large area) between February 2018 and January 2019. The crabs inhabited mountain streams at 400–1100 m. The average water depth and width were 0.6 m and 8.3 m, respectively. In total, 879 individuals were caught from PL compared to 583 individuals from PR. Male were more abundant than female in both areas. Male were also larger and heavier, with a mean weight of 145 g, mean carapace width of 76 mm and mean carapace length of 75.7 mm. The average number of crabs caught was higher in the rainy season (66.3 individuals). The crab population was larger in PL (256.7 individuals), which is bigger in size than PR and is located farther from urban areas. The average crab density in PL and PR were 1.7 and 1.6 crabs/m2, respectively. Population density was significantly correlated with body size parameters: body weight (r2 = 0.066, df = 1196, p < 0.001), carapace width (r2 = 0.053, df = 1196, p < 0.001) and carapace length (r2 = 0.067, df = 1196, p < 0.001). The findings of this study suggest that a large area size and high population density are important to the conservation of the giant mountain crab in mountainous forests.
Genetic Diversity and Fine-Scale Spatial Genetic Structure of the Endangered Shrub Birch (Betula humilis Schrk.) Populations in Protected and Unprotected Areas
Authors: Bona Agnieszka , Brzeziński Damian , Jadwiszczak Katarzyna A.
Published: August 2022

The genetic diversity of natural populations is a key factor in the success of long-term ecosystem protection. We studied the genetic diversity and spatial genetic structure (SGS) in three endangered shrub birch (Betula humilis) populations using seven nuclear microsatellite loci. The highest genetic variation was found in the restored Szuszalewo population in Biebrza National Park, where active prevention of thicket forest succession was recently conducted. The results of bottleneck tests were not statistically significant in each locality, although a genetic indication for population reduction was detected in the Rospuda stand, which is not actively protected. The Bayesian clustering, principal coordinates analysis, and FST estimates revealed the greatest difference between Magdzie Bagno and Rospuda samples. SGS was found in all B. humilis stands; however, it was the strongest in the Rospuda locality, where pollen and seed dispersal was limited by dense clusters of shrub birch ramets scattered among forest and brushwood plants. The weakest SGS, also supported by finding some sibling pairs in distant locations, was observed in the Szuszalewo population. The aforementioned results indicate that the active protection practices may impose an immediate beneficial effect on the restoration and maintenance of the B. humilis populations.
Phylogenetic Study of Alternaria Potato and Tomato Pathogens in Russia
Authors: Kokaeva Lyudmila Yu. , Yarmeeva Maria M. , Kokaeva Zarema G. , Chudinova Elena M. , Balabko Petr N. , Elansky Sergey N.
Published: August 2022

Early blight (EB) is a destructive disease affecting potato and tomato plants in Russia, caused by a heterogeneous group of plant pathogenic Alternaria fungi. The current species delimitation in Alternaria sect. Porri with medium to large conidia and a long (filamentous) beak is based on molecular data. In this study, the ITS, GAPDH, RPB2, TEF1, and Alt a 1 gene regions were analyzed in 41 large-spored Alternaria isolates obtained from diseased potato and tomato plants collected from 13 regions in Russia. Our data revealed five pathogenic species (A. alternariacida, A. grandis, A. linariae, A. protenta, and A. solani). Two species (A. solani and A. linariae) were found to be associated with early blight of tomato. Alternaria linariae and A. protenta were confirmed as the major causal agents of tomato and potato early blight, respectively. There were no phylogenetic groupings among tested Russian Alternaria isolates associated with their locality.
Ethnobotanical and Ethnopharmacological Study in the Bulgarian Rhodopes Mountains—Part _I
Authors: Mincheva Irena , Naychov Zheko , Radev Christo , Aneva Ina , Rastrelli Luca , Kozuharova Ekaterina
Published: August 2022

Traditional knowledge of medicinal plants and their uses has been well documented in Bulgaria in the past. However, we know little about the contemporary traditional application of medicinal plants. Rhodopes Mountain is an ethnobotanically poorly studied region. This region is suitable for conducting field research in ethnobotany for several reasons: (i) our preliminary observation in a number of settlements revealed that the local population, in particular, relies solely on previously collected medicinal plants in winter months even in modern times; (ii) due to the relative isolation of the area, considerable authenticity of traditional methods of medicinal plant use is retained there. The aim of this study is ethnopharmacological and ethnobotanical research among the population of the Rhodopes to evaluate the contemporary use of medicinal plants. The field ethnobotanical data were collected through the in-depth method in combination with a semi-structured face-to-face interviews, adapted with modifications to the objectives of this study. The quantitative ethnobotanical index Use Value (UV) was calculated. Here we suggested a new approach in ethnobotanical research. We used nomograms to present a large volume of medicinal plants’ application data, classified by the degree of their UV. This allows for a much broader view of collected and processed data. Data analyses from our filed research showed that the 92 informants mentioned utilization of a total of 114 plant species belonging to 52 families and 110 genera. The most common plants were from the families Asteraceae (16.7%), Lamiaceae (12.3%), Rosaceae (9.6%) and Amrillydaceae (3.5%), followed by Crassulaceae, Plantaginacea, Oleaceae and Solanaceae. The data presented in six nomograms revealed the most popular plants, the way of application and the corresponding medical indications in the Central and East Rhodopes, and the differences between the two sub-regions. Sempervivum tectorum, Tussilago farfara and Plantago major are the most often reported plants in the Central Rhodopes while these are Cotinus coggygria, Prunus spinosa and Teucrium polium in the East Rhodopes. The results of the study show that in the Rhodopes, the contemporary application of traditional medicinal plants is pretty much vivid. The locals in the Rhodopes still use the traditional knowledge and rely on plants to treat various health problems. They use common plants in a sustainable manner and are open to the cultivation of Sideritis scardica—a species which became rare after overexploitation.
Cladocera (Crustacea: Branchiopoda) of Man-Made Lakes at the Northeast Part of the United Arab Emirates with a Hypothesis on Their Origin
Authors: Kotov Alexey A. , Neretina Anna N. , Al Neyadi Shamma Eisa Salem , Karabanov Dmitry P. , Hamza Waleed
Published: August 2022

A study of the water fleas (Crustacea: Cladocera) in man-made lakes in the northeast part of the United Arab Emirates revealed five species: Ceriodaphnia cf. cornuta Sars, 1885; Daphnia (Ctenodaphnia) arabica Neretina, Al Neyadi et Hamza, 2022; Moina cf. micrura Kurz, 1875; Anthalona mediterranea (Yalim, 2005); Coronatella anemae Van Damme et Dumont, 2008. The morphologies of the four taxa are described in detail, except that of D. Arabica, which has been described previously. The phylogenies of the C. cornuta and M. micrura species groups were reconstructed based on sequences of the COI mitochondrial gene and the possible divergence age of the Arabian clades was estimated based on molecular clocks with paleontological calibration. We concluded that the C. cornuta complex was differentiated in the Upper Jurassic to Lower Cretaceous. The splitting off of clades containing the Arabian population took place during the Oligocene to Miocene. The M. micrura species group was differentiated in the Upper Cretaceous, and the splitting off of clades including Arabian populations took place around the Oligocene. Therefore, the clades (of different hierarchical orders) in the Arabian Peninsula are very old compared to clades of similar rank in northern Eurasia, which usually have Late Pleistocene history. Most of our sampled water bodies were newly constructed man-made reservoirs. As revealed, the phylogroups are locally distributed, and we hypothesized that they are colonists from surrounding natural water bodies inhabited by the relicts of older fauna that survived after the great climate aridization and then occupied newly available (man-made) biotopes.
Phylogeography of Mesophotic Coral Ecosystems: Squirrelfish and Soldierfish (Holocentriformes: Holocentridae)
Authors: Copus Joshua M. , Walsh Cameron A. J. , Hoban Mykle L. , Lee Anne M. , Pyle Richard L. , Kosaki Randall K. , Toonen Robert J. , Bowen Brian W.
Published: August 2022

Mesophotic coral ecosystems (MCEs: ~30 to 100+ m depth) may be older and more stable than shallow coral ecosystems that are more prone to disturbances in both the long term (glacial sea level cycles) and short term (heavy weather and anthropogenic activities). Here, we assess the phylogeography of two MCE fishes, the soldierfish Myripristis chryseres (N = 85) and the squirrelfish Neoniphon aurolineatus (N = 74), with mtDNA cytochrome oxidase C subunit I. Our goal is to resolve population genetic diversity across the Central and West Pacific and compare these patterns to three shallow-reef species in the same taxonomic family (Holocentridae). Significant population structure (ΦST = 0.148, p = 0.01) was observed in N. aurolineatus, while no structure was detected in M. chryseres (ΦST = −0.031, p = 0.83), a finding that matches the shallow-water congener M. berndti (ΦST = −0.007, p = 0.63) across the same range. Nucleotide diversity in the MCE fishes was low (π = 0.0024–0.0028) compared to shallow counterparts (π = 0.003–0.006). Coalescence times calculated for M. chryseres (~272,000 years) and N. aurolineatus (~284,000 years) are more recent or comparable to the shallow-water holocentrids (~220,000–916,000 years). We conclude that the shallow genetic coalescence characteristic of shallow-water marine fishes cannot be attributed to frequent disturbance. We see no evidence from holocentrid species that MCEs are older or more stable habitats.
Reproducibility and Repeatability of Coronary Computed Tomography Angiography (CCTA) Image Segmentation in Detecting Atherosclerosis: A Radiomics Study
Authors: Yunus Mardhiyati Mohd , Sabarudin Akmal , Karim Muhammad Khalis Abdul , Nohuddin Puteri N. E. , Zainal Isa Azzaki , Shamsul Mohd Shahril Mohd , Yusof Ahmad Khairuddin Mohamed
Published: August 2022

Atherosclerosis is known as the leading factor in heart disease with the highest mortality rate among the Malaysian population. Usually, the gold standard for diagnosing atherosclerosis is by using the coronary computed tomography angiography (CCTA) technique to look for plaque within the coronary artery. However, qualitative diagnosis for noncalcified atherosclerosis is vulnerable to false-positive diagnoses, as well as inconsistent reporting between observers. In this study, we assess the reproducibility and repeatability of segmenting atherosclerotic lesions manually and semiautomatically in CCTA images to identify the most appropriate CCTA image segmentation method for radiomics analysis to quantitatively extract the atherosclerotic lesion. Thirty (30) CCTA images were taken retrospectively from the radiology image database of Hospital Canselor Tuanku Muhriz (HCTM), Kuala Lumpur, Malaysia. We extract 11,700 radiomics features which include the first-order, second-order and shape features from 180 times of image segmentation. The interest vessels were segmentized manually and semiautomatically using LIFEx (Version 7.0.15, Institut Curie, Orsay, France) software by two independent radiology experts, focusing on three main coronary blood vessels. As a result, manual segmentation with a soft-tissuewindowing setting yielded higher repeatability as compared to semiautomatic segmentation with a significant intraclass correlation coefficient (intra-CC) 0.961 for thefirst-order and shape features; intra-CC of 0.924 for thesecond-order features with p < 0.001. Meanwhile, the semiautomatic segmentation has higher reproducibility as compared to manual segmentation with significant interclass correlation coefficient (inter-CC) of 0.920 (first-order features) and a good interclass correlation coefficient of 0.839 for the second-order features with p < 0.001. The first-order, shape order and second-order features for both manual and semiautomatic segmentation have an excellent percentage of reproducibility and repeatability (intra-CC > 0.9). In conclusion, semi-automated segmentation is recommended for inter-observer study while manual segmentation with soft tissue-windowing can be used for single observer study.
The Low Expression of Fc-Gamma Receptor III (CD16) and High Expression of Fc-Gamma Receptor I (CD64) on Neutrophil Granulocytes Mark Severe COVID-19 Pneumonia
Authors: Hoffmann Joerg , Etati Rojin , Brendel Cornelia , Neubauer Andreas , Mack Elisabeth
Published: August 2022

Hyperinflammation through neutrophil granulocytes contributes to disease severity in COVID-19 pneumonia and promotes acute lung failure. Understanding the mechanisms of the dysregulations within the myeloid cell compartment may help to improve therapies for severe COVID-19 infection. Here, we investigated the immunopathological characteristics of circulating neutrophil granulocytes and monocytes in 16 patients with COVID-19 pneumonia by multiparameter flow cytometry in comparison to 9 patients with pulmonary infiltrates but without COVID-19. We correlated the immunophenotypes with the scores of the severity-of-disease classification system, APACHE-II. We found that the mean fluorescence intensity (MFI) of CD15, which is important for the transendothelial migration, was significantly reduced in the patients with COVID-19 (difference ± SD; 295.70 ± 117.50 MFI; p = 0.02). In addition, the granularity was significantly lower in the neutrophil granulocytes of patients with COVID-19 (difference ± SD; 1.11 ± 0.43 side-scatter ratio; p = 0.02). Moreover, the Fc-gamma receptor III (CD16) and Fc-gamma receptor I (CD64) on the neutrophil granulocytes were expressed discordantly with COVID-19 severity. CD16 correlated as inversely proportional (ρ = (−)0.72; 95% CI (−)0.92–(−)0.23; p = 0.01) and CD64 as proportional (ρ = 0.76; 95% CI 0.31–0.93; p = 0.01) with the APACHE-II scores of the patients. We conclude that the deviant expression of the Fc-gamma receptors might play role in a dysregulated antibody-mediated phagocytosis in severe cases of COVID-19 pneumonia.
Electrocardiographic Patterns of Depolarization Abnormalities Help to Identify Reduced Left Ventricular Ejection Fraction
Authors: Gordeeva Maria , Serdiukova Irina , Krasichkov Alexander , Parmon Elena
Published: August 2022

The aim of the study was to investigate the relationship between a decrease in the left ventricular ejection fraction (EF) and traditional ECG signs associated with structural changes of the myocardium (pathological Q wave, ventricular arrhythmias) and relatively new and poorly understood (fragmented QRS complex (fQRS), early repolarization pattern (ERP)) and evaluate their significance for identifying patients with mildly reduced EF (mrEF). The study included 148 patients who were treated and examined at the Almazov Medical Research Center. FQRS, ERP, pathological Q wave, and premature ventricular contractions (PVC) were described in the analysis of the ECG, and the results of echocardiography and statistical data were analyzed: Fisher’s test and chi-square, correlation analysis, and ROC analysis. According to the level of EF, patients were divided into three groups: group 1—patients with low EF (lEF) (less than 40%), group 2—patients with mildly reduced EF (mrEF) (40–49%); group 3—patients with preserved EF (pEF) (more than 50%). In the first group (EF), fQRS was registered in 16 (51.6%) patients, in the mrEF in 16 (18.2%). Pathological Q wave was detected in lEF in 20 (65%), in mrEF in 10 (35%), 15 (18%), in pEF in 15 (18%). The fQRS has been found to be more important in identifying patients with mrEF. In lEF in 2 (6.5%) patients, in mrEF in 2 (6.9%), in pEF in 11 (12.5%). There was no relationship between ERP, the amount of PVC, and the presence of ventricular tachycardia with EF. FQRS is significantly more common occurred with a decrease in EF and may be a marker of a mrEF. Thus, fQRS is associated with mrEF and pay close attention in routine clinical practice to identify patients at high risk of developing systolic dysfunction.
Cell Toxicity Study of Antiseptic Solutions Containing Povidone–Iodine and Hydrogen Peroxide
Authors: Romano Veronica , Di Gennaro Donato , Sacco Anna Maria , Festa Enrico , Roscetto Emanuela , Basso Morena Anna , Ascione Tiziana , Balato Giovanni
Published: August 2022

The increasing incidence of periprosthetic joint infections (PJIs) has led to a growing interest in developing strategies to prevent and treat this severe complication. The surgical site’s application of antiseptic solutions to eliminate contaminating bacteria and eradicate the bacterial biofilm has been increasing over time. Even though it has been proven that combining antimicrobials could enhance their activities and help overcome acquired microbial resistance related to the topical use of antibiotics, the toxicity of integrated solutions is not well described. This study aimed to evaluate the cytotoxicity of solutions containing povidone–iodine (PI) and hydrogen peroxide (H2O2), alone or in combination, after 1.3 and 5 min of exposure. Chondrocytes, tenocytes, and fibroblast-like synoviocytes were used for cytotoxicity analysis. Trypan blue stain (0.4% in PBS) was applied to evaluate the dead cells. All solutions tested showed a progressive increase in toxicity as exposure time increased except for PI at 0.3%, which exhibited the lowest toxicity. The combined solutions reported a reduced cellular killing at 3 and 5 min than H2O2 at equal concentrations, similar results to PI solutions.
Postmortem Bacteriology in Forensic Autopsies—A Single Center Retrospective Study in Romania
Authors: Diac Iuliana , Keresztesi Arthur-Atilla , Cerghizan Anda-Mihaela , Negrea Mihai , Dogăroiu Cătălin
Published: August 2022

Postmortem bacteriology examinations have been a controversial topic over the years, though the value of postmortem bacteriology cultures remains promising. The aim of this study was to review the postmortem bacteriological sampling procedures and results in a single centre in Bucharest over a period of 10 years. Material and methods: The present study was a retrospective, single-center study, performed at the Mina Minovici National Institute of Legal Medicine in Bucharest, Romania, from 2011–2020. Results: Postmortem bacteriology was requested 630 forensic autopsies, 245 female (38.9%) and 385 male (61.1%), age range 0 and 94 years, median age of 52 years. Deaths occurred in hospital for 594 cases (94.3%) and out-of-hospital for 36 cases (5.7%—field case). Blood cultures were requested in the majority of cases, followed by tracheal swabs and lung tissue. In-hospital and out of hospital deaths did not differ significantly regarding the number of microorganisms identified in a positive blood culture. Postmortem bacteriology cultures of the respiratory tract showed a statistically significant association to microscopically confirmed lung infections. Conclusions Postmortem sampling for bacteriology testing in our center in Bucharest is heterogeneous with a high variation of patterns. A positive blood culture result for Staphylococcus species without the identification of a specific microorganism is more likely due to postmortem contamination.
Lower Bounds on Multivariate Higher Order Derivatives of Differential Entropy
Authors: Guo Laigang , Yuan Chun-Ming , Gao Xiao-Shan
Published: August 2022

This paper studies the properties of the derivatives of differential entropy H(Xt) in Costa’s entropy power inequality. For real-valued random variables, Cheng and Geng conjectured that for m≥1, (−1)m+1(dm/dtm)H(Xt)≥0, while McKean conjectured a stronger statement, whereby (−1)m+1(dm/dtm)H(Xt)≥(−1)m+1(dm/dtm)H(XGt). Here, we study the higher dimensional analogues of these conjectures. In particular, we study the veracity of the following two statements: C1(m,n):(−1)m+1(dm/dtm)H(Xt)≥0, where n denotes that Xt is a random vector taking values in Rn, and similarly, C2(m,n):(−1)m+1(dm/dtm)H(Xt)≥(−1)m+1(dm/dtm)H(XGt)≥0. In this paper, we prove some new multivariate cases: C1(3,i),i=2,3,4. Motivated by our results, we further propose a weaker version of McKean’s conjecture C3(m,n):(−1)m+1(dm/dtm)H(Xt)≥(−1)m+11n(dm/dtm)H(XGt), which is implied by C2(m,n) and implies C1(m,n). We prove some multivariate cases of this conjecture under the log-concave condition: C3(3,i),i=2,3,4 and C3(4,2). A systematic procedure to prove Cl(m,n) is proposed based on symbolic computation and semidefinite programming, and all the new results mentioned above are explicitly and strictly proved using this procedure.
Frequency Stability Prediction of Power Systems Using Vision Transformer and Copula Entropy
Authors: Liu Peili , Han Song , Rong Na , Fan Junqiu
Published: August 2022

This paper addresses the problem of frequency stability prediction (FSP) following active power disturbances in power systems by proposing a vision transformer (ViT) method that predicts frequency stability in real time. The core idea of the FSP approach employing the ViT is to use the time-series data of power system operations as ViT inputs to perform FSP accurately and quickly so that operators can decide frequency control actions, minimizing the losses caused by incidents. Additionally, due to the high-dimensional and redundant input data of the power system and the O(N2) computational complexity of the transformer, feature selection based on copula entropy (CE) is used to construct image-like data with fixed dimensions from power system operation data and remove redundant information. Moreover, no previous FSP study has taken safety margins into consideration, which may threaten the secure operation of power systems. Therefore, a frequency security index (FSI) is used to form the sample labels, which are categorized as “insecurity”, “relative security”, and “absolute security”. Finally, various case studies are carried out on a modified New England 39-bus system and a modified ACTIVSg500 system for projected 0% to 40% nonsynchronous system penetration levels. The simulation results demonstrate that the proposed method achieves state-of-the-art (SOTA) performance on normal, noisy, and incomplete datasets in comparison with eight machine-learning methods.
The Application of Life Cycle Assessment to Evaluate the Environmental Impacts of Edible Insects as a Protein Source
Authors: Vinci Giuliana , Prencipe Sabrina Antonia , Masiello Luca , Zaki Mary Giò
Published: August 2022

Animal based-food products represent an essential source of protein supply in overall diets, and livestock provide 25% of the total protein content consumed by humans as food. Concurrently, livestock significantly impacts the environment, being responsible for 10–12% of total anthropogenic CO2 emissions. Among livestock, pork is considered one that accounts for the greatest impact in terms of emissions, about 4.62 kg CO2 eq/kg. Furthermore, the growing global demand for protein sources has led to a widespread need to find agri-food solutions that meet the demand for food through sustainable production systems. The high nutritional quality of edible insects, in terms of amino acids, fats, minerals, and vitamins, is comparable with meat products. This study aims to compare protein production from pork and mealworm, assessing the degree of substitution and environmental impacts of the two production systems. To assess the impacts of protein production from mealworms and pork on the ecosystem, resources, and human health, an LCA was conducted using the ReCiPe 2016 Endpoint method, with a 100-year hierarchical perspective (H) V1.05. It emerged that pork production is characterized by high impacts on the ecosystem, land use, climate-altering emissions, and fossil resources, in contrast with mealworm protein production. The low impact of insect protein production and the high nutritional values make edible insects a sustainable solution to growing food demand and economic benefits render edible insects globally a major potential future food.
New Digital Era. Challenge of Government Proposals for the Inclusion of Indigenous Communities in the Northern Macrozone of Chile
Authors: Burgos-Videla Carmen , Miranda Horacio , Zavando Francisco
Published: August 2022

The objective of this diagnostic research was to identify the perceptions of indigenous communities regarding the digital divide and government proposals for their inclusion in formative processes. For this purpose, the Indigenous Leadership School was developed at the University of Atacama in 18 months. The hierarchical segmentation, classification and regression (CART) method was applied to identify and select the determining variables of ICT management, and once the variables were selected, the associations between them were determined with the multivariate method of multiple correspondence analysis (MCA). Binary logistic regression analysis was used to evaluate the probability of presenting poor ICT management according to the variable selected as the most determinant of this characteristic, which corresponded to age, dichotomized into those under 46 and those over 45 years of age. Finally, univariate analysis of descriptive statistics of quantitative and categorical variables, centralization, dispersion, histogram and bar graph statistics were estimated. One of the strong conclusions indicates that those older than 45 years of age are about three times more likely to show poor ICT skills than those younger than 46 years of age.
Debunking Climate Myths Is Easy—Is It Really? An Explorative Case Study with Pre-Service Physics Teachers
Authors: Schubatzky Thomas , Haagen-Schützenhöfer Claudia
Published: August 2022

Climate change is a complex topic and hence makes teaching climate change a demanding task. This is especially because climate change still represents a (socially) controversial topic and students may be confronted with misrepresentations and misinformation about climate change in their daily lives. Therefore, it is important that science teachers are equipped with skills to properly respond to or “debunk” climate change misinformation, and to train their students on how to identify and respond to misinformation. To address this, we developed an intervention based on inoculation theory and known debunking techniques to foster physics pre-service teachers’ debunking skills as well as their self-efficacy to confront climate misinformation. Through the intervention, we showed that the participants increased their debunking skills and they showed more accurate assessments of their own skills. We conclude that this approach is promising to foster pre-service teachers’ perceived competence to teach the demanding topic of climate change. Finally, our approach generally shows potential in preparing future teachers to teach other controversial topics where misinformation is abundant.
Artificial Intelligence and Learning Analytics in Teacher Education: A Systematic Review
Authors: Salas-Pilco Sdenka , Xiao Kejiang , Hu Xinyun
Published: August 2022

In recent years, artificial intelligence (AI) and learning analytics (LA) have been introduced into the field of education, where their use has great potential to enhance the teaching and learning processes. Researchers have focused on applying these technologies to teacher education, as they see the value of technology for educating. Therefore, a systematic review of the literature on AI and LA in teacher education is necessary to understand their impact in the field. Our methodology follows the PRISMA guidelines, and 30 studies related to teacher education were identified. This review analyzes and discusses the several ways in which AI and LA are being integrated in teacher education based on the studies’ goals, participants, data sources, and the tools used to enhance teaching and learning activities. The findings indicate that (a) there is a focus on studying the behaviors, perceptions, and digital competence of pre- and in-service teachers regarding the use of AI and LA in their teaching practices; (b) the main data sources are behavioral data, discourse data, and statistical data; (c) machine learning algorithms are employed in most of the studies; and (d) the ethical clearance is mentioned by few studies. The implications will be valuable for teachers and educational authorities, informing their decisions regarding the effective use of AI and LA technologies to support teacher education.
Inclusion in Uncertain Times: Changes in Practices, Perceptions, and Attitudes around Accessibility and Inclusive Practice in Higher Education
Authors: Lister Kate , Pearson Victoria K. , Coughlan Tim , Tessarolo Felipe
Published: August 2022

Accessibility, inclusive teaching, and student support are multi-faceted; they are dependent on wider institutional factors, such as leadership, resource, systems, and culture. To be truly inclusive requires a whole institution approach, with voices, perspectives, and stakeholder buy-in sought from across the institution. This can be extremely challenging because these can be sensitive to myriad institutional, sector, and societal changes that can influence working practices, resource management, and capacity. In this paper, we analyse responses from three iterations of a biennial staff survey conducted in 2017, 2019, and 2021 at the Open University (OU), capturing views on accessibility and inclusion before and during the COVID-19 pandemic and other challenging circumstances. These responses, from tutors, module and programme teams, educational technologists, library staff, and student support teams, reveal crucial insight into the (in)accessibility of support and practice across the institution, as well as insight into staff skills, attitudes, and knowledge around accessibility, and the fitness for purpose of the systems and structures in place. In this analysis, we explore how staff practices and perceptions change over time; identify the themes that remain constant over time, despite global circumstances; and explore how these themes can inform a whole-institution approach to accessibility and inclusion.
An Effective Sharding Consensus Algorithm for Blockchain Systems
Authors: Chen Runyu , Wang Lunwen , Peng Chuang , Zhu Rangang
Published: August 2022

Sharding is the widely used approach to the trilemma of simultaneously achieving decentralization, security, and scalability in traditional blockchain systems. However, existing schemes generally involve problems such as uneven shard arithmetic power and insecure cross-shard transaction processing. In this study, we used the Practical Byzantine Fault Tolerance (PBFT) as the intra-shard consensus and, here, we propose a new sharding consensus mechanism. Firstly, we combined a jump consistent hash algorithm with signature Anchorhash to minimize the mapping of the node assignment. Then, we improved the process of the cross-shard transaction and used the activity of nodes participating in intra-shard transactions as the criterion for the shard reconfiguration, which ensured the security of the blockchain system. Meanwhile, we analyzed the motivation mechanism from two perspectives. Finally, through theoretical analysis and related experiments, we not only verified that the algorithm can ensure the security of the entire system, but also further clarified the necessary conditions to ensure the effectiveness of the shards and the system on the original basis.
DAVE: Deep Learning-Based Asymmetric Virtual Environment for Immersive Experiential Metaverse Content
Authors: Cho Yunsik , Hong Seunghyun , Kim Mingyu , Kim Jinmo
Published: August 2022

In this study, we design an interface optimized for the platform by adopting deep learning in an asymmetric virtual environment where virtual reality (VR) and augmented reality (AR) users participate together. We also propose a novel experience environment called deep learning-based asymmetric virtual environment (DAVE) for immersive experiential metaverse content. First, VR users use their real hands to intuitively interact with the virtual environment and objects. A gesture interface is designed based on deep learning to directly link gestures to actions. AR users interact with virtual scenes, objects, and VR users via a touch-based input method in a mobile platform environment. A text interface is designed using deep learning to directly link handwritten text to actions. This study aims to propose a novel asymmetric virtual environment via an intuitive, easy, and fast interactive interface design as well as to create metaverse content for an experience environment and a survey experiment. This survey experiment is conducted with users to statistically analyze and investigate user interface satisfaction, user experience, and user presence in the experience environment.
Tag Estimation Method for ALOHA RFID System Based on Machine Learning Classifiers
Authors: Dujić Rodić Lea , Stančić Ivo , Zovko Kristina , Perković Toni , Šolić Petar
Published: August 2022

In the last two decades, Radio Frequency Identification (RFID) technology has attained prominent performance improvement and has been recognized as one of the key enablers of the Internet of Things (IoT) concepts. In parallel, extensive employment of Machine Learning (ML) algorithms in diverse IoT areas has led to numerous advantages that increase successful utilization in different scenarios. The work presented in this paper provides a use-case feasibility analysis of the implementation of ML algorithms for the estimation of ALOHA-based frame size in the RIFD Gen2 system. Findings presented in this research indicate that the examined ML algorithms can be deployed on modern state-of-the-art resource-constrained microcontrollers enhancing system throughput. In addition, such utilization can cope with latency since the execution time is sufficient to meet protocol needs.