bluuebunny/crossref_metadata_2025 huggingface dataset:
Diagnosis of Prostate Cancer through the Multi-Ligand Binding of Prostate-Derived Extracellular Vesicles and miRNA Analysis
Authors: Zabegina Lidia , Zyatchin Ilya , Kniazeva Margarita , Shalaev Andrey , Berkut Maria , Sharoyko Vladimir , Mikhailovskii Vladimir , Kondratov Kirill , Reva Sergey , Nosov Alexandr , Malek Anastasia
Published: March 2023

Background: The development of new non-invasive markers for prostate cancer (PC) diagnosis, prognosis, and management is an important issue that needs to be addressed to decrease PC mortality. Small extracellular vesicles (SEVs) secreted by prostate gland or prostate cancer cells into the plasma are considered next-generation diagnostic tools because their chemical composition might reflect the PC development. The population of plasma vesicles is extremely heterogeneous. The study aimed to explore a new approach for prostate-derived SEV isolation followed by vesicular miRNA analysis. Methods: We used superparamagnetic particles functionalized by five types of DNA-aptamers binding the surface markers of prostate cells. Specificity of binding was assayed by AuNP-aptasensor. Prostate-derived SEVs were isolated from the plasma of 36 PC patients and 18 healthy donors and used for the assessment of twelve PC-associated miRNAs. The amplification ratio (amp-ratio) value was obtained for all pairs of miRNAs, and the diagnostic significance of these parameters was evaluated. Results: The multi-ligand binding approach doubled the efficiency of prostate-derived SEVs’ isolation and made it possible to purify a sufficient amount of vesicular RNA. The neighbor clusterization, using three pairs of microRNAs (miR-205/miR-375, miR-26b/miR375, and miR-20a/miR-375), allowed us to distinguish PC patients and donors with sensitivity—94%, specificity—76%, and accuracy—87%. Moreover, the amp-ratios of other miRNAs pairs reflected such parameters as plasma PSA level, prostate volume, and Gleason score of PC. Conclusions: Multi-ligand isolation of prostate-derived vesicles followed by vesicular miRNA analysis is a promising method for PC diagnosis and monitoring.
Tocilizumab for Severe COVID-19 Infection and Multisystem Inflammatory Syndrome in Adults and Children
Authors: Edinoff Amber N. , Alpaugh Edward Sanders , Newgaard Olivia , Wajid Irza , Klapper Rachel J. , Cornett Elyse M. , Kaye Adam M. , Iyer Praneet , Kaye Alan D.
Published: March 2023

Coronavirus disease 2019 (COVID-19) rapidly emerged as a global pandemic, placing imminent stress and burden on healthcare resources and workers worldwide. Many patients who present with a severe COVID-19 infection are at high risk of developing severe acute respiratory distress syndrome (ARDS), leading to a vast number of patients requiring mechanical ventilation and a high mortality rate. Similar to Middle East respiratory syndrome, COVID-19 demonstrates an initial viral replication phase that manifests as a variety of symptoms typically flu-like in nature, followed by a profound inflammatory response leading to rapid production of cytokines and uncontrolled inflammation. There have also been many cases of COVID-19 in pediatric patients presenting with elevated inflammatory markers and multisystem involvement labeled as a multisystem inflammatory syndrome (MIS-C) by the world health organization (WHO). The recent treatment of systemic inflammatory response to COVID-19 targets the secondary phase involving cytokine release syndrome. The detrimental effects of IL-6 can be profound and elevated levels are associated with a higher mortality rate and mechanical ventilation. Tocilizumab is an IL-6 inhibitor most widely investigated to target cytokine storm syndrome. Since June 2021, the FDA enacted an emergency use authorization for tocilizumab in the treatment of COVID-19. Several clinical trials have investigated tocilizumab combined with corticosteroids for treating severe ARDS associated with COVID-19. An increasing amount of evidence suggests that targeting the cytokine storm syndrome related to COVID-19 can lead to improved outcomes, especially in those patients requiring mechanical ventilation and with a critical illness. Additional studies are warranted to further look at the positive effects of tocilizumab in the COVID-19 population while additionally defining possible adverse effects.
The Difference in Tribological Characteristics between CFRPEEK and Stainless Steel under Water Lubrication in Friction Testing Machine and Axial Piston Pump
Authors: Li Donglin , Ma Xianshuai , Wang Shuai , Wang Junhua , Yang Fang , Liu Yinshui
Published: March 2023

A water lubricating axial piston pump (WLPP) is the core power component of a green and environmentally friendly water hydraulic system. The friction and wear of the friction pairs of a WLPP are the key factors that restrict its development. In order to explore the friction and wear mechanism of materials, the tribological properties of CFRPEEK against 316L and 1Cr17Ni2 under water lubrication were investigated in a friction testing machine and an axial piston pump, respectively. An environmental scanning electron microscope (ESEM), confocal laser scanning microscopy and a surface profiler were used to analyze the morphology of the samples. In a friction testing machine, two different metals are paired with CFRPEEK, and the friction coefficient and wear rate barely show any differences. The wear rate of CFRPEEK is two orders of magnitude higher than that of metal. In the WLPP, 316L can hardly be paired with CFRPEEK, while 1Cr17Ni2 works well. The wear of 1Cr17Ni2 in the WLPP is greater than that of CFRPEEK. The high-pressure water film lubrication friction pairs cause the wear of the metal and show the difference in these two test methods. The wear mechanism is mainly abrasive wear. Improving the wear resistance of metals is very important for the development of WLPP.
Ultimate Shear Force of an Any Anchor Group Post-Installed into Concrete
Authors: Foraboschi Paolo
Published: March 2023

This paper is devoted to the fastening system that consists of a number of anchors of approximately equal effective embedment depth, called “anchor group”, embedded into hardened concrete, used to transmit forces transverse to the anchors from an attachment to the concrete. The anchor group is far from the edges and is subjected to no more than marginal axial forces. Being post-installed, rather than cast-in, the embedded end of each anchor is not hooked, and no nuts, washers, or plates are attached to the embedded shaft. The paper focuses on the transverse forces that can be transmitted across an anchor group from an attachment to the concrete. The paper provides an analytical model for predicting the maximum (ultimate) shear force that an anchor group can bear, thus called “shear strength”. The model hence allows the structural designer to predict the shear strength of an anchor group post-installed into concrete. The model is based on five mechanical assumptions, which were established from a wide-ranging numerical analysis. Model predictions turned out to be, on average, 20% lower than the results of experiments performed on cast-in anchor groups borrowed from literature. The comparison verifies model accuracy, considering that the tested anchor groups benefitted from the extra-strength furnished by nuts and washers attached to the embedded shaft. Model predictions were also compared to code provisions; the former resulted to be up to one third of the latter. The paper presents and comments those comparisons, as well as all mathematical development. Applications of the model to wide-ranging case studies is presented and discussed as well.
Role of Surface-Active Element Sulfur on Thermal Behavior, Driving Forces, Fluid Flow and Solute Dilution in Laser Linear Welding of Dissimilar Metals
Authors: Shu Zhuang , Yu Gang , Dong Binxin , He Xiuli , Li Zhiyong , Li Shaoxia
Published: March 2023

Understanding heat and mass transfer and fluid flow in the molten pool is very helpful in the selection and optimization of processing parameters, and the surface-active element has an important effect on the heat and mass transfer in laser welding of dissimilar metals. A three-dimensional (3D) numerical model coupled with a sub-model of surface tension, which considers the influence of local temperature and the concentration of surface-active element sulfur at the gas/liquid surface, is used to analyze the thermal behavior, driving forces, fluid flow, and solute dilution during laser linear welding of 304SS and Ni. The relationship between surface tension, driving forces, and the temperature coefficient of surface tension with the spatial distribution of temperature and the surface-active element sulfur is quantitatively analyzed. The simulation results show that the molten pool is fully developed at 45 ms, and the collision of inward and outward convection, with the maximum velocity reaching 1.7 m/s, occurs at the isotherm with a temperature between 2200 K and 2500 K. The temperature-gradient term and concentration-gradient term of surface shear stress play different roles in different positions of the free surface. The local sulfur concentration changes the temperature sensitivity of the surface tension at different sides of the free surface and further determines the transition of convection. Complex fluid flow promotes solute dilution, and the distribution of solute becomes uniform from the front to the rear of the molten pool. The Ni element is transferred to 304SS mainly at the rear side. The work provides theoretical support for the control of joint quality by changing the content of surface-active elements in dissimilar welding.
Porous Polymers Based on 9,10-Bis(methacryloyloxymethyl)anthracene—Towards Synthesis and Characterization
Authors: Maciejewska Małgorzata , Józwicki Mateusz
Published: March 2023

Porous materials can be found in numerous essential applications. They are of particular interest when, in addition to their porosity, they have other advantageous properties such as thermal stability or chemical diversity. The main aim of this study was to synthesize the porous copolymers of 9,10-bis(methacryloyloxymethyl)anthracene (BMA) with three different co-monomers divinylbenzene (DVB), ethylene glycol dimethacrylate (EGDMA) and trimethylpropane trimethacrylate (TRIM). They were synthesized via suspension polymerization using chlorobenzene and toluene served as porogenic solvents. For the characterization of the synthesized copolymers ATR-FTIR spectroscopy, a low-temperature nitrogen adsorption–desorption method, thermogravimetry, scanning electron microscopy, inverse gas chromatography and size distribution analysis were successfully employed. It was found that depending on the used co-monomer and the type of porogen regular polymeric microspheres with a specific surface area in the range of 134–472 m2/g can be effectively synthesized. The presence of miscellaneous functional groups promotes divergent types of interactions Moreover, all of the copolymers show a good thermal stability up to 307 °C. What is important, thanks to application of anthracene derivatives as the functional monomer, the synthesized materials show fluorescence under UV radiation. The obtained microspheres can be used in various adsorption techniques as well as precursor for thermally resistant fluorescent sensors.
Influence of Accidental Impurities on the Spectroscopic and Luminescent Properties of ZnWO4 Crystal
Authors: Subbotin Kirill , Titov Anatolii , Solomatina Victoria , Khomyakov Andrew , Pakina Ekaterina , Yakovlev Viktor , Valiev Damir , Zykova Marina , Kuleshova Kristina , Didenko Yana , Lis Denis , Grishechkin Mikhail , Batygov Sergei , Kuznetsov Sergei , Avetissov Igor
Published: March 2023

Special techniques for deep purification of ZnO and WO3 have been developed in this work. A ZnWO4 single crystal has been grown by the Czochralski method using purified ZnO and WO3 chemicals, along with the ZnWO4 crystal-etalon, which has been grown at the same conditions using commercially available 5N ZnO and WO3 chemicals. The actual accidental impurities compositions of both the initial chemicals and the grown crystals have been measured by inductively coupled plasma mass-spectrometry. A complex of comparative spectroscopic studies of the crystals has been performed, including optical absorption spectra, photo-, X-ray-, and cathodoluminescence spectra and decay kinetics, as well as the photoluminescence excitation spectra. The revealed differences in the measured properties of the crystals have been analyzed in terms of influence of the accidental impurities on these properties.
The Influence of Diisocyanate Structure on Thermal Stability of Thermoplastic Polyurethane Elastomers Based on Diphenylmethane-Derivative Chain Extender with Sulfur Atoms
Authors: Rogulska Magdalena
Published: March 2023

The work is a continuation of the research on thermoplastic polyurethane (TPU) elastomers containing sulfur atoms which are incorporated into the polyurethane chain using aliphatic-aromatic chain extenders. These materials show some improved properties in relation to conventional ones, e.g., adhesion to metals, bacterial resistance and refractive index. The present study deals with the detailed characteristics of the process of thermal decomposition of TPU elastomers obtained from 2,2′-[methylenebis(1,4-phenylenemethylenethio)]diethanol, 1,1′-methanediylbis(4-isocyanatobenzene) (MDI) or 1,6-diisocyanatohexane (HDI) and poly(oxytetramethylene) diol of Mn = 2000 g/mol by thermogravimetric analysis coupled on-line with Fourier transform infrared spectroscopy. The analysis was performed under inert and oxidative conditions. All TPU elastomers were found to have a relatively good thermal stability, with those based on aromatic diisocyanate being at an advantage. In helium, they are stable up to 280–282 °C (from HDI) and 299–301 °C (from MDI), whereas in synthetic air up to 252–265 °C (from HDI) and 261–272 °C (from MDI), as measured by the temperature of 1% mass loss. Depending on the content of the hard segments and the tested atmosphere, the TPU elastomers decompose from one to four stages. From the analysis of the volatile decomposition products, it follows that the decomposition of both types of hard segments was accompanied by the evolution of carbonyl sulfide, carbon dioxide, water, sulfide dioxide, alcohols and aromatic compounds. For the hard segment derived from HDI, isocyanates, amines, and unsaturated compounds were also identified, while for the MDI-derived one, aldehydes were discovered. In turn, the polyether soft segment decomposed mainly into aliphatic ethers, aldehydes, and carbon monoxide.
Accuracy of Dental Models Fabricated Using Recycled Poly-Lactic Acid
Authors: Nagata Koudai , Inaba Keitaro , Kimoto Katsuhiko , Kawana Hiromasa
Published: March 2023

Based on the hypothesis that the fabrication of dental models using fused deposition modeling and poly-lactic acid (PLA), followed by recycling and reusing, would reduce industrial waste, we aimed to compare the accuracies of virgin and recycled PLA models. The PLA models were recycled using a crusher and a filament-manufacturing machine. Virgin PLA was labeled R, and the first, second, and third recycles were labeled R1, R2, and R3, respectively. To determine the accuracies of the virgin and reused PLA models, identical provisional crowns were fitted, and marginal fits were obtained using micro-computed tomography. A marginal fit of 120 µm was deemed acceptable based on previous literature. The mesial, distal, buccal, and palatal centers were set at M, D, B, and P, respectively. The mean value of each measurement point was considered as the result. When comparing the accuracies of R and R1, R2, and R3, significant differences were noted between R and R3 at B, R and R2, R3 at P, and R and R3 at D (p < 0.05). No significant difference was observed at M. This study demonstrates that PLA can be recycled only once owing to accuracy limitations.
A Time-Domain Signal Processing Algorithm for Data-Driven Drive-by Inspection Methods: An Experimental Study
Authors: Lan Yifu , Li Zhenkun , Lin Weiwei
Published: March 2023

Constructional material deterioration and member damage can cause changes in the dynamic characteristics of bridge structures, and such changes can be tracked in the responses of passing vehicles via the vehicle-bridge interaction (VBI). Though data-driven methods have shown promising results in damage inspection for drive-by methods, there is still much room for improvement in their performance. Given this background, this paper proposes a novel time-domain signal processing algorithm for the raw vehicle acceleration data of data-driven drive-by inspection methods. To achieve the best data processing performance, an optimizing strategy is designed to automatically search for the optimal parameters, tuning the algorithm. The proposed method intentionally overcomes the difficulties in the application of drive-by methods, such as measurement noise, speed variance, and enormous data volumes. Meanwhile, the use of this method can greatly improve the accuracy and efficiency of Machine Learning (ML) models in vehicle-based damage detection. It consists of a filtering process to denoise the data, a pooling process to reduce data redundancy, and an optimizing procedure to maximize algorithm performance. A dataset is obtained to validate the proposed algorithm through laboratory experiments with a scale truck model and a steel beam. The results show that, compared to using raw data, the present algorithm can increase the average accuracy by 12.2–15.0%, and the average efficiency by 35.7–96.7% for different damaged cases and ML models. Additionally, the functions of filtering and pooling operations, the influence of window function parameters, as well as the performance of different sensor locations, are also investigated in the paper. The goal is to present a signal processing algorithm for data-driven drive-by inspection methods to improve their detection performance of bridge damage caused by material deterioration or structural change.
First-Principles Study of the Magnetic and Electronic Structure of NdB4
Authors: Tao Pengyan , Ma Jiangjiang , Li Shujing , Shao Xiaohong , Wang Baotian
Published: March 2023

Due to their magnetic and physical properties, rare earth magnetic borides have been applied to a variety of critical technologies. In particular, rare earth tetraborides are more abundant as frustrated antiferromagnets. Here, the atomic structures, magnetic structures, and electronic structures of NdB4 have been studied by first-principle calculations. The ground state magnetic structure of NdB4 is determined. Moreover, the small energy difference between different magnetic structures means that there may be more than one magnetic structure that coexist. One can glean from the electronic structure of the magnetic ground state that the d orbital of Nd is strongly hybridized with the p orbital of B, and the f electron of Nd is highly localized. The computational results reveal the complexity of the magnetic structure and provide a theoretical basis for studying the magnetic ground state of NdB4.
A Simple Method for Estimation of the Scattering Exponent of Nanostructured Glasses
Authors: Shepilov Michael , Dymshits Olga , Zhilin Aleksandr
Published: March 2023

For most of nanostructured glasses (NGs) (phase-separated glasses and glass-ceramics), the light scattering coefficient (turbidity) is described by a power function of the inverse wavelength with an exponent which differs appreciably from the Rayleigh value 4 and is called the scattering exponent. The knowledge of the scattering exponent of a material is important from both fundamental and practical points of view. Previously, we developed three rather complex methods to determine the scattering exponent. Here, we present a novel simple express method for its estimation. In the method, the measured optical density for only one sample is used, the refractive index of the material is not required, and the dispersion of refractive index is assumed to be insignificant. The method is based on the differentiation of the measured optical density with respect to the wavelength. The scattering exponent values obtained by the new method for NGs of different types are in good agreement with those found by the traditional methods. The new method is found to be applicable even to NGs with high dispersion of refractive index. Thus, the new method does not require the data on the refractive index dispersion and can be applied without restrictions.
Effects of Nitrite/Nitrate-Based Accelerators on Strength and Deformation of Cementitious Repair Materials under Low-Temperature Conditions
Authors: Choi Heesup , Inoue Masumi , Choi Hyeonggil , Lim Myungkwan , Kim Jihoon
Published: March 2023

This study aimed to develop a cementitious repair material that can be constructed in cold weather conditions. The addition of nitrite/nitrate-based antifreezing agents has been shown to increase the initial strength of cementitious repair materials in cold weather. However, increasing the amount of these agents may lead to an increase in deformation behavior and shrinkage cracking. In this study, the effects of different types and amounts of nitrite/nitrate-based antifreezing agents on the strength development and deformation behavior of cementitious repair materials under low-temperature conditions were evaluated. As a result, it was found that the addition of a large amount of calcium nitrite can promote hydration and improve the initial strength of the repair material, irrespective of the type of antifreezing agent. However, this also leads to an increase in shrinkage and the concern of shrinkage cracking. Therefore, a repair material that is repairable in winter was developed by balancing the initial strength and deformation behavior through the appropriate selection of antifreezing agents. The developed repair material can be used to repair structures in cold weather conditions, which is of great significance for the construction industry in Hokkaido, Japan.
Comparison of the Micro-Shear Bond Strength of Resin Cements to CAD/CAM Glass Ceramics with Various Surface Treatments
Authors: Sağlam Gaye , Cengiz Seda , Köroğlu Ayşegül , Şahin Onur , Velioğlu Neslin
Published: March 2023

This study aimed to compare the effect of acid etching, sandblasting, or silica coating on the micro-shear bond strength of dual-cured resin cements to computer-aided design and computer-aided manufacturing (CAD/CAM) glass ceramic materials. Feldspathic, lithium disilicate, and zirconia-reinforced CAD/CAM ceramics were divided into four groups: control group (C), no surface treatment; hydrofluoric (HF) group, 5% HF acid-etched; sandblasting (SB) group, abraded with 50 µm aluminum oxide (Al2O3) particles; silica-coated (CJ) group, abraded with 30 µm silica-modified Al2O3 particles. Roughness values were obtained by using a profilometer. The cements were condensed on the surface-treated specimens and a micro-shear bond test was conducted. The ceramic material (p < 0.001) and surface treatment type (p < 0.001) significantly affected the micro-shear bond strength values. HF acid etching can be recommended for the surface pretreatment of feldspathic, lithium disilicate, and zirconia-reinforced CAD/CAM ceramics. Better bond strengths can be obtained with HF acid etching than with sandblasting and silica coating.
Microstructure and Mechanical Properties of Gradient Interfaces in Wire Arc Additive Remanufacturing of Hot Forging Die Steel
Authors: Ni Mao , Hu Zeqi , Qin Xunpeng , Xiong Xiaochen , Ji Feilong
Published: March 2023

Hot forging dies are subjected to periodic thermal stress and often fail in the forms of thermal fatigue, wear, plastic deformation, and fracture. A gradient multi-material wire arc additive remanufacturing method for hot forging dies was proposed to extend the service life of hot forging dies and reduce total production costs. The properties of multi-material gradient interfaces play a critical role in determining the overall performance of the final products. In this study, the remanufacturing zone of a hot forging die was divided into three deposition layers: the transition layer, the intermediate layer, and the strengthening layer. Experiments of wire arc additive manufacturing with gradient material were conducted on a 5CrNiMo hot forging die steel. The microstructure, microhardness, bonding strength, and impact property of gradient interfaces were characterized and analyzed. The results revealed that the gradient additive layers and their interfaces were defect-free and that the gradient interfaces had obtained a high-strength metallurgical bonding. The microstructure of the gradient additive layers presented a gradient transformation process of bainite-to-martensite from the bottom to the top layer. The microhardness gradually increased from the substrate layer to the surface-strengthening layer, forming a three-level gradient in the range of 100 HV. The impact toughness values of the three interfaces were 46.15 J/cm2, 54.96 J/cm2, and 22.53 J/cm2, and the impact fracture morphology ranged from ductile fracture to quasi-cleavage fracture. The mechanical properties of the gradient interfaces showed a gradient increase in hardness and strength, and a gradient decrease in toughness. The practical application of hot forging die remanufactured by the proposed method had an increase of 37.5% in average lifespan, which provided scientific support for the engineering application of the gradient multi-material wire arc additive remanufacturing of hot forging dies.
Process of Pure Copper Fabricated by Selective Laser Melting (SLM) Technology under Moderate Laser Power with Re-Melting Strategy
Authors: Hu Rong , Su Kangjing , Lao Zibin , Cai Yixun , Fu Bin , Yuen Matthew M. F. , Gao Zhaoli , Cao Mingxuan , Wang Ying
Published: March 2023

Pure copper (Cu) material, because of its high thermal conductivity, can be 3D printed to fabricate effective thermal management components. However, in the selective laser melting (SLM) process, due to copper’s high optical reflectivity, Cu-based parts need to be printed using high laser power. In this study, we demonstrated 3D printing with a re-melting strategy is able to fabricate high-density and low-surface-roughness pure copper parts using only a moderate laser (350 W) power. The effect of the re-scan to initial scan speed ratio on the printing quality resulting from the re-melting strategy is discussed. The re-melting strategy is likened to a localized annealing process that promotes the recrystallization of the newly formed copper microstructures on the re-scan path. Given a hatch spacing of 0.06 mm and a powder layer thickness of 0.05 mm, Cu samples with 93.8% density and low surface roughness (Sa~22.9 μm) were produced using an optimized scan speed of 200 mm/s and a re-scanning speed of 400 mm/s, with a laser power of 350 W. Our work provides an approach to optimize the laser power for printing pure copper 3D parts with high relative density (low porosity) and low surface roughness while ensuring the lifetime stability of the part. The re-melting strategies have broad implications in 3D printing and are particularly relevant for metals with high reflectivity, such as pure copper.
The Cracking of Al-Mg Alloys Welded by MIG and FSW under Slow Strain Rating
Authors: Dudzik Krzysztof , Czechowski Mirosław
Published: March 2023

Al-Mg alloys used in the shipbuilding industry were tested. The most commonly used alloy AW 5083 and alloy AW 5059 with higher strength properties were selected. Both native materials and their joints welded by the traditional MIG arc welding method and the friction stir welding (FSW) method were tested. Both methods are approved by classification societies which allow them to be used in construction by the shipbuilding industry. The research was carried out in two stages. The first study was an “in-situ tensile test in SEM”. The surfaces of the deformed specimens’ changes were observed in the vacuum chamber of a Philips XL30 scanning electron microscope. During the tests, the force and elongation of the specimen were recorded. In addition, a chemical analysis of selected precipitates was performed by energy dispersive spectrometry (EDS) using the EDAX adapter. Slip lines were observed on the surface of the tested specimens, which are arranged in bands in the native material and in a disordered manner in the joints welded by MIG and FSW methods. Cracking starts mainly through decohesion at the matrix-precipitate interfaces. In the second stage of the research, slow strain rate testing (SSRT) was carried out in accordance with ISO 7539-7:2005. The tests were carried out on a specially designed test stand, where the FT-5307 strain gauge force sensor with a measuring range of 0–16 kN was used to measure the force value. The PSz 20 transducer with a measuring range of 0–20 mm was also used. The test consisted of subjecting the specimen to increasing deformation with the strain rate έ = 1.6 × 10−6 s−1 until destruction. The fracture surfaces of the SSRT specimens were subjected to fractographic analysis using a Philips XL-30 scanning electron microscope. The results of fractographic studies after the SSRT test of the native materials and their joints welded by the MIG and FSW methods indicate that the trans-crystalline cracking mechanism is dominant, characterized by ductile fracture, and cracks are initiated at the interfaces of the precipitates with the matrix. The research results show that the plastic deformation increases and micro-cracks develop and merge into a main crack, which, after reaching the critical dimension, rapidly develops, causing the destruction of the material. The fracture micrographs of the specimens of base metals and their joints welded by FSW and MIG after the SSRT test allow us to conclude that the cracking mechanism was trans-crystalline ductile.
The Effects of Curing Temperature on CH-Based Fly Ash Composites
Authors: Ji Xiangnan , Takasu Koji , Suyama Hiroki , Koyamada Hidehiro
Published: March 2023

Curing temperature affects the compressive strength of cement paste systems via the pozzolanic reaction. However, different processes, climates, and weather conditions often result in different initial curing temperatures. The relationship between curing temperature and compressive strength is still an underexplored domain. To explore the effect of curing temperature on calcium hydroxide (CH)-based fly ash composites, fly ashes from different carbon sources were used to make CH-based composites, and the compressive strength, reaction rate, CH content, and C-S-H generation were analyzed. The correlation between the reaction rate and C-S-H content was analyzed. High-temperature curing improved the compressive strength of the cement paste system by affecting the CH-based reaction rate in the initial stage, with the highest initial reaction rate reaching 28.29%. However, after cooling to constant temperature, high-temperature curing leads to a decrease in CH and C-S-H content. The average decrease rate of calcium hydroxide content under high temperature curing is 38%, which is about 2.38 times that of room-temperature curing conditions. This led to a decrease in the compressive strength of the cement paste. Therefore, the performance of CH-based fly ash composites produced by low-temperature curing was superior to that of composites produced by high-temperature curing.
Bonding Performance of Surface-Treated Zirconia Cantilevered Resin-Bonded Fixed Dental Prostheses: In Vitro Evaluation and Finite Element Analysis
Authors: Malgaj Tine , Papšík Roman , Abram Anže , Kocjan Andraž , Jevnikar Peter
Published: March 2023

Debonding of zirconia cantilevered resin-bonded fixed dental prostheses (RBFDPs) remains the main treatment complication, therefore, the present in vitro study aimed to evaluate the effect of different surface pretreatments on the bonding of zirconia RBFDPs. Eighty milled zirconia maxillary central incisors, with complementary zirconia cantilevered RBFDPs, were randomly subjected to four different surface pretreatments (n = 20): as-machined (AM); airborne-particle abraded (APA); coated with nanostructured alumina coating (NAC); incisor air-abraded and RBFDP coated (NAC_APA). After bonding, half of each group (n = 10) was stored in deionized water (150 days/37 °C), thermocycled (37,500 cycles, 5–55 °C), and cyclically loaded (50 N/1.2 × 106). Load-bearing capacity (LBC) was determined using a quasi-static test. Additionally, finite element analysis (FEA) and fractography were performed. t-test and one-way ANOVA were used for statistical-analysis. Before aging, the NAC group provided superior LBC to other groups (p < 0.05). After aging, the AM specimens debonded spontaneously, while other groups exhibited comparable LBC (p ˃ 0.05). The FEA results correlated with the in vitro experiment and fractography, showing highly stressed areas in the bonding interface, cement layer, and in RBFDP’s retainer wing and connector. The NAC RBFDPs exhibited comparable long-term bonding performance to APA and should be regarded as a zirconia pretreatment alternative to APA.
Study on Dynamic Mechanical Properties of Carbon Fiber-Reinforced Polymer Laminates at Ultra-Low Temperatures
Authors: Zhao Wenhao , Lin Sanchun , Wang Wenfeng , Yang Yifan , Yan Xuan , Yang Heng
Published: March 2023

This study uses experimental methods, theoretical research, and numerical prediction to study the dynamic mechanical properties and damage evolution of CFRP laminates at ultra-low temperatures. Based on the Split Hopkinson Pressure Bar (SHPB) device, we set up an ultra-low temperature dynamic experimental platform with a synchronous observation function; the dynamic mechanical properties of laminates were tested, and the damage evolution process was observed. The experimental results are as follows: The compression strength and modulus increase linearly with the increase in strain rate and show a quadratic function trend of increasing and then decreasing with the decrease in temperature. The damage degree of the dynamic bending sample increases obviously with the impact velocity and decreases first and then increases with the decrease in temperature. Based on the low-temperature dynamic damage constitutive, failure criterion, and interlayer interface damage constitutive of the laminates, a numerical model was established to predict the dynamic mechanical properties and damage evolution process of CFRP laminates at ultra-low temperatures, and the finite element analysis (FEA) results are consistent with the experimental results. The results of this paper strongly support the application and safety evaluation of CFRP composites in extreme environments, such as deep space exploration.
Efficient Image Encryption Scheme Using Novel 1D Multiparametric Dynamical Tent Map and Parallel Computing
Authors: Daoui Achraf , Yamni Mohamed , Chelloug Samia Allaoua , Wani Mudasir Ahmad , El-Latif Ahmed A. Abd
Published: March 2023

In order to ensure reliable and secure image exchange, chaotic systems are often considered for their good performance in information security. In this work, we first propose an extended version of a chaotic tent map (TM)—the multiparametric 1D tent map (MTM). The latter contains six control parameters defined over an unlimited range. These parameters strongly influence the MTM output when they are slightly modified by ∓10−13, which makes MTM stronger than the existing TM and other 1D chaotic maps in terms of security key space. Then, this paper proposes a simple, yet powerful method to make uniform the distribution of chaotic sequence values, making the latter suitable for use in cryptosystems. Next, a new image cryptosystem is introduced based on MTM and parallel computing. This computing mode is incorporated to boost the security level of our scheme and to speed up its runtime. Indeed, in only one running round, our encryption scheme generates a security key of space equal to 1078×n with n indicating the number of the available CPU cores. Therefore, the suggested scheme achieves a good trade-off between safety and efficiency. The results of the performed comparisons and numerical experiments indicate on the one hand that MTM exhibits good chaotic characteristics in comparison to its original version. On the other hand, the suggested cryptosystem demonstrates good strength against various kinds of attacks (brute force, statistical, classical, noise, differential, etc.). Furthermore, comparison with similar schemes indicate that the proposed scheme is competitive in terms of execution time and superior in terms of security level.
Solitonic Aspect of Relativistic Magneto-Fluid Spacetime with Some Specific Vector Fields
Authors: Siddiqi Mohd Danish , Mofarreh Fatemah , Chaubey Sudhakar Kumar
Published: March 2023

The target of the current research article is to investigate the solitonic attributes of relativistic magneto-fluid spacetime (MFST) if its metrics are Ricci–Yamabe soliton (RY-soliton) and gradient Ricci–Yamabe soliton (GRY-soliton). We exhibit that a magneto-fluid spacetime filled with a magneto-fluid density ρ, magnetic field strength H, and magnetic permeability μ obeys the Einstein field equation without the cosmic constant being a generalized quasi-Einstein spacetime manifold (GQE). In such a spacetime, we obtain an EoS with a constant scalar curvature R in terms of the magnetic field strength H and magnetic permeability μ. Next, we achieve some cauterization of the magneto-fluid spacetime in terms of Ricci–Yamabe solitons with a time-like torse-forming vector field ξ and a φ(Ric) vector field. We establish the existence of a black hole in the relativistic magneto-fluid spacetime by demonstrating that it admits a shrinking Ricci–Yamabe soliton and satisfies the time-like energy convergence criteria. In addition, we examine the magneto-fluid spacetime with a gradient Ricci–Yamabe soliton and deduce some conditions for an equation of state (EoS) ω=−15 with a Killing vector field. Furthermore, we demonstrate that the EoS ω=−15 of the magneto-fluid spacetime under some constraints represents a star model and a static, spherically symmetric perfect fluid spacetime. Finally, we prove that a gradient Ricci–Yamabe soliton with the conditions μ=0 or H=2; μ≠0, H>2 and obeying the equation of state ω=−15 is conceded in a magneto-fluid spacetime, and a naked singularity with a Cauchy horizon subsequently emerges, respectively.
A Co-Optimization Algorithm Utilizing Particle Swarm Optimization for Linguistic Time Series
Authors: Hieu Nguyen Duy , Linh Mai Van , Phong Pham Dinh
Published: March 2023

The linguistic time-series forecasting model (LTS-FM), which has been recently proposed, uses linguistic words of linguistic variable domains generated by hedge algebras (HAs) to describe historical numeric time-series data. Then, the LTS-FM was established by utilizing real numeric semantics of words induced by the fuzziness parameter values (FPVs) of HAs. In the existing LTS-FMs, just the FPVs of HAs are optimized, while the used word set is still chosen by human experts. This paper proposes a co-optimization method of selecting the optimal used word set that best describes numeric time-series data in parallel with choosing the best FPVs of HAs to improve the accuracy of LTS-FMs by utilizing particle swarm optimization (PSO). In this co-optimization method, the outer loop optimizes the FPVs of HAs, while the inner loop optimizes the used word set. The experimental results on three datasets, i.e., the “enrollments of the University of Alabama” (EUA), the “killed in car road accidents in Belgium” (CAB), and the “spot gold in Turkey” (SGT), showed that our proposed forecasting model outperformed the existing forecasting models in terms of forecast accuracy.
Full-Reference Image Quality Assessment with Transformer and DISTS
Authors: Tsai Pei-Fen , Peng Huai-Nan , Liao Chia-Hung , Yuan Shyan-Ming
Published: March 2023

To improve data transmission efficiency, image compression is a commonly used method with the disadvantage of accompanying image distortion. There are many image restoration (IR) algorithms, and one of the most advanced algorithms is the generative adversarial network (GAN)-based method with a high correlation to the human visual system (HVS). To evaluate the performance of GAN-based IR algorithms, we proposed an ensemble image quality assessment (IQA) called ATDIQA (Auxiliary Transformer with DISTS IQA) to give weights on multiscale features global self-attention transformers and local features of convolutional neural network (CNN) IQA of DISTS. The result not only performed better on the perceptual image processing algorithms (PIPAL) dataset with images by GAN IR algorithms but also has good model generalization over LIVE and TID2013 as traditional distorted image datasets. The ATDIQA ensemble successfully demonstrates its performance with a high correlation with the human judgment score of distorted images.
Coordinated Economic Operation of Hydrothermal Units with HVDC Link Based on Lagrange Multipliers
Authors: Ahmad Ali , Kashif Syed Abdul Rahman , Ashraf Arslan , Gulzar Muhammad Majid , Alqahtani Mohammed , Khalid Muhammad
Published: March 2023

Coordinated operation of hydrothermal scheduling with HVDC links considering network constraints becomes a vital issue due to their remote location and recent induction in the existing power system. The nonlinear and complex nature of the problem introduces many variables and constraints which results in a heavy computational burden. A widespread approach for handling these complexities is to reformulate the problem by several linearization methods. In this paper, a Lagrange multipliers-based method is proposed for the solution of hydrothermal economic scheduling including HVDC link. This method solves equality constraint optimization problems. The linear programming approach is embedded with the Lagrange method to consider both equality and inequality constraints. The proposed technique has been used on piecewise linear variables and constraints of the system considering generation, water volume, and line power flow limits. The formulated method efficiently minimizes the operational cost of thermal units and maximizes the utilization of hydro units while meeting all generation, water volume, and the HVDC link constraints. The method was successfully implemented in two scenarios of a case study. In the first scenario, hydrothermal scheduling was performed on the typical network without an HVDC line limit and equal nodal prices were found with minimal thermal generation cost of $278,822.3. In the second scenario, the proposed method optimally dispatches units to meet the HVDC line limit and minimizes thermal generation cost to $279,025.4 while satisfying hydro, thermal, and other operating constraints. Both scenarios are implemented for a 24 h period. The results have been presented to illustrate the performance of the proposed method.
Cohomology Algebras of a Family of DG Skew Polynomial Algebras
Authors: Mao Xuefeng , Ren Gui
Published: March 2023

Let A be a connected cochain DG algebra such that its underlying graded algebra A# is the graded skew polynomial algebra k⟨x1,x2,x3⟩/x1x2+x2x1x2x3+x3x2x3x1+x1x3,|x1|=|x2|=|x3|=1. Then the differential ∂A is determined by ∂A(x1)∂A(x2)∂A(x3)=Mx12x22x32 for some M∈M3(k). When the rank r(M) of M belongs to {1,2,3}, we compute H(A) case by case. The computational results in this paper give substantial support for the research of the various homological properties of such DG algebras. We find some examples, which indicate that the cohomology graded algebras of such kind of DG algebras may be not left (right) Gorenstein.
Glycosaminoglycans from the Starfish Lethasterias fusca: Structures and Influence on Hematopoiesis
Authors: Bilan Maria I. , Anisimova Natalia Yu. , Tokatly Alexandra I. , Nikogosova Sofya P. , Vinnitskiy Dmitriy Z. , Ustyuzhanina Nadezhda E. , Dmitrenok Andrey S. , Tsvetkova Evgenia A. , Kiselevskiy Mikhail V. , Nifantiev Nikolay E. , Usov Anatolii I.
Published: March 2023

Crude anionic polysaccharides extracted from the Pacific starfish Lethasterias fusca were purified by anion-exchange chromatography. The main fraction LF, having MW 14.5 kDa and dispersity 1.28 (data of gel-permeation chromatography), was solvolytically desulfated and giving rise to preparation LF-deS with a structure of dermatan core [→3)-β-d-GalNAc-(1→4)-α-l-IdoA-(1→]n, which was identified according to NMR spectroscopy data. Analysis of the NMR spectra of the parent fraction LF led to identification of the main component as dermatan sulfate LF-Derm →3)-β-d-GalNAc4R-(1→4)-α-l-IdoA2R3S-(1→ (where R was SO3 or H), bearing sulfate groups at O-3 or both at O-2 and O-3 of α-l-iduronic acid, as well as at O-4 of some N-acetyl-d-galactosamine residues. The minor signals in NMR spectra of LF were assigned as resonances of heparinoid LF-Hep composed of the fragments →4)-α-d-GlcNS3S6S-(1→4)-α-l-IdoA2S3S-(1→. The 3-O-sulfated and 2,3-di-O-sulfated iduronic acid residues are very unusual for natural glycosaminoglycans, and further studies are needed to elucidate their possible specific influence on the biological activity of the corresponding polysaccharides. To confirm the presence of these units in LF-Derm and LF-Hep, a series of variously sulfated model 3-aminopropyl iduronosides were synthesized and their NMR spectra were compared with those of the polysaccharides. Preparations LF and LF-deS were studied as stimulators of hematopoiesis in vitro. Surprisingly, it was found that both preparations were active in these tests, and hence, the high level of sulfation is not necessary for hematopoiesis stimulation in this particular case.
Perception of Minimum Interventional Dentistry among Dental Undergraduate Students and Interns
Authors: Abdelhafeez Manal M. , Alharbi Fatima M. , Srivastava Swati , Eldwakhly Elzahraa , Saadaldin Selma A. , Soliman Mai
Published: March 2023

Background: The philosophy of minimum interventional dentistry (MID) is to integrate prevention, remineralization, and minimal intervention for the placement and replacement of restorations. All branches of dentistry play an important role in practicing MID, and their primary goal is to realize that any restoration is of less biological significance than the healthy original tissue Objectives: The objective of this study was to assess the perception of MID among dental undergraduate students and interns in terms of knowledge, attitude, and practice at the College of Dentistry. Materials and Methods: This cross-sectional study was conducted among undergraduate students and interns at the College of Dentistry, Qassim University, Saudi Arabia. A self-administered questionnaire was distributed, which included basic demographic profiles and questions about the knowledge, attitude, and practices toward MID. The data were tabulated in MS Excel, and all statistical analyses were performed using SPSS version 21. Results: A total of 163 dental students were recruited, with senior students comprising 73% and interns comprising 27%. Male students were slightly more prevalent (50.9%) than female students (49.1%). About 37.6% of participants received training about MID during educational courses, while 10.3% received it during their internship. A statistical test revealed that the prevalence of interns who were trained in performing MID was significantly higher (p < 0.001). Conclusions: The majority of the participants demonstrated proper knowledge, attitude, and practice in different aspects of MID. Interns reported a higher rate of knowledge, attitude, and practice in MID compared to undergraduate students. However, more education and hands-on training about MID concepts during the college curriculum are necessary to attain better knowledge, attitude, and practices that could be useful for more conservative clinical practice.