bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of Sirtuins in the Pathogenesis of Rheumatoid Arthritis
Authors: Poniewierska-Baran Agata , Bochniak Oliwia , Warias Paulina , Pawlik Andrzej
Published: January 2023

Rheumatoid arthritis (RA) is an autoimmune and inflammatory disease leading to joint destruction. The causes of RA are not fully known. Most likely, the development of the disease depends on the coexistence of many factors, such as hereditary factors, immune system defects, gender, infectious agents, nicotine, and stress. Various epigenetic changes have been identified and correlated with the aggressive phenotype of RA, including the involvement of sirtuins, which are enzymes found in all living organisms. Their high content in the human body can slow down the aging processes, reduce cell death, counteract the appearance of inflammation, and regulate metabolic processes. Sirtuins can participate in several steps of RA pathogenesis. This narrative review presents, collects, and discusses the role of all sirtuins (1–7) in the pathogenesis of rheumatoid arthritis.
Solubility of Amino Acids in the Eutectic Solvent Constituted by Sodium Acetate Trihydrate and Urea and in Its Mixture with Water
Authors: Gallego Cristina , Rodríguez Héctor , Soto Ana
Published: January 2023

Industrial fish and aquaculture processing leads to the generation of a huge quantity of by-products, whose accumulation and mismanagement involve serious environmental consequences as well as high economic losses. Taking advantage of these residues as a source of added-value compounds must be a priority in a circular economy. This work is a preliminary study to analyze the possibility of using the eutectic mixture of urea and sodium acetate trihydrate as a solvent for collagen extraction. To that end, the solid–liquid equilibrium of the system was determined in order to define the exact composition and temperature of the eutectic. The solubility in this solvent of the main amino acids that constitute fish collagen was studied at several temperatures and atmospheric pressure. At 308.15 K, solubilities of the major constituents of the target protein, namely L-proline, trans-4-hydroxy-L-proline, and glycine, were 0.19, 0.16, and 0.12 (mass fraction), respectively. These values increased with temperature. Dilution with water (50 wt%) allowed operation at lower temperature and led to an increase in the solubilities. The van ‘t Hoff model was satisfactorily used to correlate the experimental data and to calculate apparent properties of dissolution. All the dissolution processes studied herein are endothermic, non-spontaneous, and enthalpy-driven. Both the eutectic and its mixture with water are promising solvents for the design of an environmentally benign process for collagen extraction.
Neural Network in the Analysis of the MR Signal as an Image Segmentation Tool for the Determination of T1 and T2 Relaxation Times with Application to Cancer Cell Culture
Authors: Truszkiewicz Adrian , Bartusik-Aebisher Dorota , Wojtas Łukasz , Cieślar Grzegorz , Kawczyk-Krupka Aleksandra , Aebisher David
Published: January 2023

Artificial intelligence has been entering medical research. Today, manufacturers of diagnostic instruments are including algorithms based on neural networks. Neural networks are quickly entering all branches of medical research and beyond. Analyzing the PubMed database from the last 5 years (2017 to 2021), we see that the number of responses to the query “neural network in medicine” exceeds 10,500 papers. Deep learning algorithms are of particular importance in oncology. This paper presents the use of neural networks to analyze the magnetic resonance imaging (MRI) images used to determine MRI relaxometry of the samples. Relaxometry is becoming an increasingly common tool in diagnostics. The aim of this work was to optimize the processing time of DICOM images by using a neural network implemented in the MATLAB package by The MathWorks with the patternnet function. The application of a neural network helps to eliminate spaces in which there are no objects with characteristics matching the phenomenon of longitudinal or transverse MRI relaxation. The result of this work is the elimination of aerated spaces in MRI images. The whole algorithm was implemented as an application in the MATLAB package.
Pathogenesis and Treatment of Pruritus Associated with Chronic Kidney Disease and Cholestasis
Authors: Kim Jin-Cheol , Shim Won-Sik , Kwak In-Suk , Lee Dong-Hun , Park Jin-Seo , Lee So-Yeon , Kang Seok-Young , Chung Bo-Young , Park Chun-Wook , Kim Hye-One
Published: January 2023

Itching is an unpleasant sensation that provokes the desire to scratch. In general, itching is caused by dermatologic diseases, but it can also be caused by systemic diseases. Since itching hampers patients’ quality of life, it is important to understand the appropriate treatment and pathophysiology of pruritus caused by systemic diseases to improve the quality of life. Mechanisms are being studied through animal or human studies, and various treatments are being tested through clinical trials. We report current trends of two major systemic diseases: chronic kidney disease and cholestatic liver disease. This review summarizes the causes and pathophysiology of systemic diseases with pruritus and appropriate treatments. This article will contribute to patients’ quality of life. Further research will help understand the mechanisms and develop new strategies in the future.
Stimulation of Tomato Drought Tolerance by PHYTOCHROME A and B1B2 Mutations
Authors: Abdellatif Islam M. Y. , Yuan Shaoze , Yoshihara Shizue , Suzaki Takuya , Ezura Hiroshi , Miura Kenji
Published: January 2023

Drought stress is a severe environmental issue that threatens agriculture at a large scale. PHYTOCHROMES (PHYs) are important photoreceptors in plants that control plant growth and development and are involved in plant stress response. The aim of this study was to identify the role of PHYs in the tomato cv. ‘Moneymaker’ under drought conditions. The tomato genome contains five PHYs, among which mutant lines in tomato PHYA and PHYB (B1 and B2) were used. Compared to the WT, phyA and phyB1B2 mutants exhibited drought tolerance and showed inhibition of electrolyte leakage and malondialdehyde accumulation, indicating decreased membrane damage in the leaves. Both phy mutants also inhibited oxidative damage by enhancing the expression of reactive oxygen species (ROS) scavenger genes, inhibiting hydrogen peroxide (H2O2) accumulation, and enhancing the percentage of antioxidant activities via DPPH test. Moreover, expression levels of several aquaporins were significantly higher in phyA and phyB1B2, and the relative water content (RWC) in leaves was higher than the RWC in the WT under drought stress, suggesting the enhancement of hydration status in the phy mutants. Therefore, inhibition of oxidative damage in phyA and phyB1B2 mutants may mitigate the harmful effects of drought by preventing membrane damage and conserving the plant hydrostatus.
A CRISPR-Cas Cure for HIV/AIDS
Authors: Hussein Mouraya , Molina Mariano A. , Berkhout Ben , Herrera-Carrillo Elena
Published: January 2023

Human immunodeficiency virus (HIV) infections and HIV-induced acquired immunodeficiency syndrome (AIDS) continue to represent a global health burden. There is currently no effective vaccine, nor any cure, for HIV infections; existing antiretroviral therapy can suppress viral replication, but only as long as antiviral drugs are taken. HIV infects cells of the host immune system, and it can establish a long-lived viral reservoir, which can be targeted and edited through gene therapy. Gene editing platforms based on the clustered regularly interspaced palindromic repeat-Cas system (CRISPR-Cas) have been recognized as promising tools in the development of gene therapies for HIV infections. In this review, we evaluate the current landscape of CRISPR-Cas-based therapies against HIV, with an emphasis on the infection biology of the virus as well as the activity of host restriction factors. We discuss the potential of a combined CRISPR-Cas approach that targets host and viral genes to activate antiviral host factors and inhibit viral replication simultaneously. Lastly, we focus on the challenges and potential solutions of CRISPR-Cas gene editing approaches in achieving an HIV cure.
Secretory Phospholipases A2, from Snakebite Envenoming to a Myriad of Inflammation Associated Human Diseases—What Is the Secret of Their Activity?
Authors: Tonello Fiorella
Published: January 2023

Secreted phospholipases of type A2 (sPLA2s) are proteins of 14–16 kDa present in mammals in different forms and at different body sites. They are involved in lipid transformation processes, and consequently in various immune, inflammatory, and metabolic processes. sPLA2s are also major components of snake venoms, endowed with various toxic and pharmacological properties. The activity of sPLA2s is not limited to the enzymatic one but, through interaction with different types of molecules, they exert other activities that are still little known and explored, both outside and inside the cells, as they can be endocytosed. The aim of this review is to analyze three features of sPLA2s, yet under-explored, knowledge of which could be crucial to understanding the activity of these proteins. The first feature is their disulphide bridge pattern, which has always been considered immutable and necessary for their stability, but which might instead be modulable. The second characteristic is their ability to undergo various post-translational modifications that would control their interaction with other molecules. The third feature is their ability to participate in active molecular condensates both on the surface and within the cell. Finally, the implications of these features in the design of anti-inflammatory drugs are discussed.
ProNGF Expression and Targeting in Glioblastoma Multiforme
Authors: Marsland Mark , Dowdell Amiee , Faulkner Sam , Jobling Phillip , Rush Robert A. , Gedye Craig , Lynam James , Griffin Cassandra P. , Baker Mark , Marsland Joanne , Jiang Chen Chen , Hondermarck Hubert
Published: January 2023

Glioblastoma multiforme (GBM) is the most lethal adult brain cancer. Temozolomide (TMZ), the standard chemotherapeutic drug used in GBM, has limited benefit and alternate therapies are needed to improve GBM treatment. Nerve growth factor (NGF) and its precursor proNGF are increasingly recognized as stimulators of human tumor progression. The expression and stimulatory effect of NGF on GBM cell growth has previously been reported, but the status of proNGF in GBM is unreported. In this study, we have investigated proNGF expression and biological activity in GBM. A clinical cohort of GBM (n = 72) and low-grade glioma (n = 20) was analyzed by immunohistochemistry for proNGF and digital quantification. ProNGF expression was significantly increased in GBM compared to low grade gliomas and proNGF was also detected in patient plasma samples. ProNGF was also detected in most GBM cell lines by Western blotting. Although anti-proNGF blocking antibodies inhibited cell growth in GBM cells with methylated MGMT gene promoter, targeting proNGF could not potentiate the efficacy of TMZ. In subcutaneous xenograft of human GBM cells, anti-proNGF antibodies slightly reduced tumor volume but had no impact on TMZ efficacy. In conclusion, this data reveals that proNGF is overexpressed in GBM and can stimulate cancer cell growth. The potential of proNGF as a clinical biomarker and therapeutic target warrants further investigations.
Physical Activity of Young Patients following Minimally Invasive Lateral Unicompartmental Knee Replacement
Authors: Hariri Mustafa , Hagemann Merlin , Mick Paul , Deisenhofer Julian , Panzram Benjamin , Innmann Moritz , Reiner Tobias , Renkawitz Tobias , Walker Tilman
Published: January 2023

Unicompartmental knee replacement (UKR) has increased in popularity in recent years, especially in young patients with high demands on their athletic ability. To date, there are no data available on the physical activity of young patients following lateral UKR. The aim of this study was to demonstrate return-to-activity rate and sporting activity of patients aged 60 years or younger following lateral UKR with a fixed-bearing (FB) prosthesis. Thirty-seven patients aged 60 years or younger after lateral FB-UKR were included. Sporting activities were assessed using the University of California Los Angeles activity scale (UCLA) and the Tegner activity score (TAS). Clinical outcome was measured using the Oxford Knee Score (OKS), range of motion (ROM) and visual analogue scale (VAS). The mean follow-up (FU) was 3.1 ± 1.5 years and the mean age at surgery was 52.8 ± 3.1 years. The return-to-activity rate was 87.5% and 49% of patients were highly active postoperatively as defined by an UCLA score of 7 or higher. All clinical parameters increased significantly postoperatively. We demonstrated a high return-to-activity rate with nearly half of the patients achieving high activity levels. Longer FU periods are necessary to evaluate the effect of activity on implant survival.
Nanocomposites of Terbium Sulfide Nanoparticles with a Chitosan Capping Agent for Antibacterial Applications
Authors: Kusrini Eny , Safira Alya Irma , Usman Anwar , Prasetyanto Eko Adi , Nugrahaningtyas Khoirina Dwi , Santosa Sri Juari , Wilson Lee D.
Published: January 2023

This study aims to investigate the effect of alkaline pH on the bottom-up synthesis of nanocomposites (NCs) containing terbium sulfide nanoparticles (Tb2S3 NPs), where chitosan (CS) was employed as a capping agent, along with evaluation of the antibacterial activity of these NCs. The NCs were characterized using spectroscopy (FESEM-EDX, Raman, FTIR, XRD, XPS, and DLS), zeta-potential, and TGA. The results of FE-SEM, XPS, Raman, and FTIR characterization support the formation of CS-Tb2S3 NPs. A pH variation from 9 to 11 during composite formation was shown to affect the size and composition of NCs. The antibacterial activity of CS-Tb2S3 NCs was studied by coating onto commercial contact lenses, where the best loading efficiency of NCs was 48%. The NCs prepared at pH 10 (without contact lenses) had greater antibacterial activity against Staphylococcus aureus, with a zone of inhibition diameter of 7.15 mm. The coating of NCs onto commercial contact lenses was less effective for inhibition of Staphylococcus aureus, in contrast with the greater activity observed for tetracycline. CS-Tb2S3 NCs offer promising antimicrobial properties that can be further optimized by control of the surface loading and accessibility of Tb2S3 NPs through further study of the role of the chitosan capping agent, since steric effects due to CS are likely to attenuate antimicrobial activity via reduced electron transfer in such nanocomposite systems.
Coastal Evolution and Relative Sea Level Changes at Psatha (Alkyonides Bay, Greece)
Authors: Karkani Anna , Evelpidou Niki , Saitis Giannis , Tsanakas Konstantinos , Drinia Hara , Vassilakis Emmanuel , Karymbalis Efthimios , Batzakis Dimitrios-Vasileios
Published: January 2023

Geomorphological and sedimentological indicators are often used to reconstruct not only coastal evolution, but also relative sea level changes. In this work, we studied the coastal sediments of Psatha bay (Alkyonides Gulf, Greece) and beachrock outcrops in order to reconstruct the coastal evolution of the area. The drillings analysis included stratigraphy, sediment texture and radiocarbon dating. Detailed mapping of the beachrocks was accomplished using DGPS-GNSS, as well as mineralogical analysis and OSL dating of beachrock samples. The new beachrock index points indicate a sea level that fell by 0.64 ± 0.13 m since 2200 ± 210 years BP and by 0.95 ± 0.13 m since 4160 ± 320 years BP, as a direct result of its location near the uplifting footwall of Psatha fault, suggesting further a rate of tectonic uplift of ~0.26 mm/yr for the late Holocene.
Optimization of Maintenance Schedule for Containerships Sailing in the Adriatic Sea
Authors: Degiuli Nastia , Farkas Andrea , Martić Ivana , Grlj Carlo Giorgio
Published: January 2023

Biofouling attaches to immersed surfaces in between hull cleanings. Due to high speeds and relatively short port times, biofilm often attaches to the immersed surfaces of containerships. In most cases, this type of fouling is not given much importance since it is assumed that it will not cause any fouling penalties. In this paper, the fouling penalties related to fouling with biofilm on the example of the Post Panamax and Post Panamax Plus containership fleets sailing in the Adriatic Sea are assessed. In addition, the investigation is performed for real environmental conditions that a containership can encounter on a sailing route passing through the Adriatic Sea. Thus, the impact of waves and wind is taken into account based on mean values of significant wave height and wind speed for containerships sailing at the design speed along the analyzed route. The procedure for the determination of the detrimental effects of biofilm on the increase in fuel consumption and carbon dioxide emissions is given. Further, the proposed procedure includes the determination of calm water resistance by the Holtrop and Mennen method, the added resistance in waves by Liu and Papanikolaou’s method, spectral analysis using the Tabain’s spectrum for the Adriatic Sea, the wind resistance by the Blendermann method, and added resistance due to biofouling using the Granville method. Thereafter, a time-dependent biofouling growth model proposed by Uzun et al. is incorporated, and the adequate timing for underwater hull cleaning is determined for several hull cleaning costs. The obtained results demonstrate that, from an environmental point of view, proactive hull cleaning should be applied, while, from an economic perspective, optimal timing for underwater hull cleaning is recommended.
Optimization Design of Pressure Hull for Long-Range Underwater Glider Based on Energy Consumption Constraints
Authors: Zhang Jianxing , Li Baoren , Peng Yuxuan , Zou Daming , Yang Gang
Published: January 2023

Underwater gliders are a class of ocean observation equipment driven by buoyancy, and their energy consumption source is mainly generated by the active regulation of buoyancy. The periodic elastic deformation of the pressure hull during the upward and downward movement of the underwater glider can have a large impact on its driving buoyancy. This paper relates the optimization problem of the pressure hull with the energy consumption of underwater glider, and the energy improvement factor is taken as the optimization objective. Based on the mechanical theory, the theoretical optimization model and constraint model are derived. A hybrid genetic simulated annealing algorithm (HGSAA) is adopted to optimize the pressure hull of the underwater glider developed by Huazhong University of Science and Technology (HUST). Additionally, the effectiveness of the optimized mathematical model and optimization results were verified by the tests. The sea trial results show that after the pressure hull optimization, the energy consumption of the buoyancy regulation unit decreased by 21.9%, and the total energy carried increased by 12.4%.
Analysis of the Sabellaria spinulosa Bioconstruction Growth in a Laboratory
Authors: Lisco Stefania , Lazic Tamara , Pierri Cataldo , Mele Daniela , de Luca Alessia , Moretti Massimo
Published: January 2023

Sabellaria spinulosa (Leukhart, 1849) is a suspension feeding polychaeta that lives in tubes consisting of terrigenous particles captured by the worm itself. They form impressive reefs containing millions of worm tubes. In temperate marine areas, under optimal environmental conditions, these structures can become natural breakwaters and can play an active role in sandy beaches’ defense. In this work, we report procedures aimed to analyze the growth of S. spinulosa bioconstructions in laboratory. By collecting biological replicas from a wild reef, this study aimed to identify sedimentological characteristics of sands that induce faster tube growth. During the tank experiments, the grain size and mineralogy of the sand were modified. By employing thin sections and X-ray microtomography analyses, the structures observed and measured during and after the tests were analogous to those naturally formed. The fastest growth was recorded in the presence of bioclastic sands with a grain size between 125 and 350 μm. Defining the physical conditions that induce faster growth is fundamental for the defense of these vulnerable habitats but also the surrounding marine environment. This study also lays the foundations for coastal protection interventions in which bioconstructions grown in the tank could be directly implanted on submerged natural and artificial substrates that are already present in situ.
New Methylcitrate Synthase Inhibitor Induces Proteolysis, Lipid Degradation and Pyruvate Excretion in Paracoccidioides brasiliensis
Authors: Rocha Olivia Basso , Freitas e Silva Kleber Santiago , Santos Thaynara Gonzaga , Moraes Dayane , Assunção Leandro do Prado , Bailão Alexandre Melo , Soares Célia Maria de Almeida , Pereira Maristela
Published: January 2023

Background: Paracoccidioidomycosis is a systemic mycosis caused by the inhalation of conidia of the genus Paracoccidioides. During the infectious process, fungal cells use several carbon sources, leading to the production of propionyl-CoA. The latter is metabolized by the methylcitrate synthase, a key enzyme of the methylcitrate cycle. We identified an inhibitor compound (ZINC08964784) that showed antifungal activity against P. brasiliensis. Methods: This work aimed to understand the fungal metabolic response of P. brasiliensis cells exposed to ZINC08964784 through a proteomics approach. We used a glucose-free medium supplemented with propionate in order to simulate the environment found by the pathogen during the infection. We performed pyruvate dosage, proteolytic assay, dosage of intracellular lipids and quantification of reactive oxygen species in order to validate the proteomic results. Results: The proteomic analysis indicated that the fungal cells undergo a metabolic shift due to the inhibition of the methylcitrate cycle and the generation of reactive species. Proteolytic enzymes were induced, driving amino acids into degradation for energy production. In addition, glycolysis and the citric acid cycle were down-regulated while ß-oxidation was up-regulated. The accumulation of pyruvate and propionyl-CoA led the cells to a state of oxidative stress in the presence of ZINC08964784. Conclusions: The inhibition of methylcitrate synthase caused by the compound promoted a metabolic shift in P. brasiliensis damaging energy production and generating oxidative stress. Hence, the compound is a promising alternative for developing new strategies of therapies against paracoccidioidomycosis.
The Effect of Sub-Lethal Successive Applications of Photodynamic Therapy on Candida albicans Biofilm Depends on the Photosensitizer
Authors: Dias Luana Mendonça , Klein Marlise Inêz , Ferrisse Túlio Morandin , Medeiros Karine Sousa , Jordão Cláudia Carolina , Bellini Amanda , Pavarina Ana Claudia
Published: January 2023

This study aimed to evaluate the potential of successive applications of sub-lethal doses of the antimicrobial photodynamic therapy (aPDT) mediated by Photodithazine® (PDZ) and curcumin (CUR) associated with LED in the viability, reactive oxygen species (ROS) production, and gene expression of Candida albicans. The microbial assays were performed using planktonic cultures and biofilms. Ten successive applications (Apl#) were performed: aPDT (P+L+; C+L+), photosensitizer (P+L−; C+L−), and LED (P−L+; C−L+). Control groups were used (P−L−; C−L−). The viability of C. albicans was determined by cultivating treated cultures on agar plates with or without fluconazole (FLU). In addition, the ROS detection and expression of SOD1, CAP1, and ERG11 genes were determined. For planktonic cultures, no viable colonies were observed after Apl#3 (without FLU) and Apl#2 (with FLU) for either photosensitizer. Biofilm treated with P+L+ resulted in the absence of cell viability after Apl#7, while C+L+ showed ~1.40 log10 increase in cell viability after Apl#2, regardless of FLU. For both photosensitizers, after the last application with viable colonies, the production of ROS was higher in the biofilms than in the planktonic cultures, and SOD1 expression was the highest in P+L+. A reduction of CAP1 and ERG11 expression occurred after P+L+, regardless of FLU. C+L+ had a higher level of ROS, and the treatments were non-significant for gene expression. Sub-lethal doses of aPDT mediated by CUR could induce C. albicans resistance in biofilms, while C. albicans cells in biofilms were susceptible to aPDT mediated by PDZ.
Dynamic Response and Damage Accumulation of Laminated Composites under Repeated Low-Velocity Impacts
Authors: Sun Jin , Huang Linhai , Dai Yunfeng
Published: January 2023

The mechanical response and damage accumulation of carbon-fiber-reinforced composite laminates subjected to repeated low-velocity impacts were experimentally investigated. The repeated impact tests were conducted on [902/−452/02/452]S quasi-isotropic and [902/02]2S cross-ply composite laminates under 16.8 J impact energy, respectively. For each impact, impact responses such as force-time, force-displacement and energy-time curves were recorded. The trends of peak force, maximum central displacement, energy absorption rate and bending stiffness with the increasing impact number were summarized, and the maximum number of repeated impacts corresponded to the occurrence of penetration events. The results showed that the delamination initiation, fiber breakage and penetration were the three typical characteristics describing the damage evolution of the repeated impacts. The damage accumulation of both the laminates was characterized by employing appropriate damage indices. By contrast, the quasi-isotropic laminates had higher impact resistance and damage tolerance, and their damage accumulation was relatively slower.
One More Step towards a Circular Economy for Thermal Insulation Materials—Development of Composites Highly Filled with Waste Polyurethane (PU) Foam for Potential Use in the Building Industry
Authors: Kowalczyk Łukasz , Korol Jerzy , Chmielnicki Błażej , Laska Aleksandra , Chuchala Daniel , Hejna Aleksander
Published: January 2023

The rapid development of the building sector has created increased demand for novel materials and technologies, while on the other hand resulting in the generation of a severe amount of waste materials. Among these are polyurethane (PU) foams, which are commonly applied as thermal insulation materials. Their management is a serious industrial problem, due to, for example, their complex chemical composition. Although some chemical and thermochemical methods of PU foam recycling are known, their broader use is limited due to requirements related to the complexity and safety of their installation, thus implicating high costs. Therefore, material recycling poses a promising alternative. The incorporation of waste PU foams as fillers for polymer composites could make it possible to take advantage of their structure and performance. Herein, polypropylene-based composites that were highly filled with waste PU foam and modified using foaming agents were prepared and analyzed. Depending on the foam loading and the foaming agent applied, the apparent density of material was reduced by as much as 68%. The efficient development of a porous structure, confirmed by scanning electron microscopy and high-resolution computed micro-tomography, enabled a 64% decrease in the thermal conductivity coefficient. The foaming of the structure affected the mechanical performance of composites, resulting in a deterioration of their tensile and compressive performance. Therefore, developing samples of the analyzed composites with the desired performance would require identifying the proper balance between mechanical strength and economic, as well as ecological (share of waste material in composite, apparent density of material), considerations.
Preparation and Microstructure of High-Activity Spherical TaNbTiZr Refractory High-Entropy Alloy Powders
Authors: Gao Shenghan , Fu Ao , Xie Zhonghao , Liao Tao , Cao Yuankui , Liu Bin
Published: January 2023

High-activity spherical TaNbTiZr refractory high-entropy alloy (REHA) powders were successfully prepared by electrode induction melting gas atomization (EIGA) and plasma rotating electrode process (PREP) methods. Both the EIGAed and PREPed TaNbTiZr RHEA powders have a single-phase body-centered cubic (BCC) structure and low oxygen content. Compared with the EIGAed powders, the PREPed powders exhibit higher sphericity and smoother surface, but larger particle size. The average particle sizes of the EIGAed and PREPed powders are 51.8 and 65.9 μm, respectively. In addition, both the coarse EIGAed and PREPed powders have dendritic structure, and the dendrite size of the EIGAed powders is larger than that of the PREPed powders. Theoretical calculation indicates that the cooling rate of the PREPed powders is one order of magnitude higher than that of the EIGAed powders during the solidification process, and the dendritic structure has more time to grow during EIGA, which is the main reason for the coarser dendrite size of the EIGAed powders.
In Situ Synthesis of Hierarchical Flower-like Sn/SnO2 Heterogeneous Structure for Ethanol GAS Detection
Authors: Zhu Ye , Yang Li , Guo Shenghui , Hou Ming , Ma Yanjia
Published: January 2023

In this study, morphogenetic-based Sn/SnO2 graded-structure composites were created by synthesizing two-dimensional SnO sheets using a hydrothermal technique, self-assembling into flower-like structures with an average petal width of roughly 3 um. The morphology and structure of the as-synthesized samples were characterized by utilizing SEM, XRD, XPS, etc. The gas-sensing characteristics of gas sensors based on the flower-like Sn/SnO2 were thoroughly researched. The sensor displayed exceptional selectivity, a rapid response time of 4 s, and an ultrahigh response at 250 °C (Ra/Rg = 17.46). The excellent and enhanced ethanol-gas-sensing properties were mainly owing to the three-dimensional structure and the rise in the Schottky barrier caused by the in situ production of tin particles.
Determination of Johnson–Cook Constitutive of 15-5 PH Steel Processed by Selective Laser Melting
Authors: Zhang Xiaojing , Yao Wenjin , Zhu Xintao , Hu Zhiming , Zhu Wei , Huang Hongxin , Li Wenbin
Published: January 2023

To obtain a Johnson–Cook model of 15-5 PH steel formed by selective laser melting (SLM), and to determine the difference between the forging process, in this work, mechanical testing, penetration testing and numerical simulations were used to study 15-5 PH steel formed by SLM and forging. Finally, the Johnson–Cook model parameters and failure parameters of the 15-5 PH steel formed by SLM and forging were obtained. We found that the SLM process was beneficial for refining the grain size of 15-5 PH steel and for improving the mechanical properties of 15-5 PH steel, where the yield strength of its specimens increased by 13.1% compared with the forged specimens. The error between the numerical simulations and penetration tests was less than 10%, which verified the validity of the numerical model parameters. It was also found that the penetration ability and abrasion resistance of the SLM-shaped projectiles were slightly superior to those of the forged projectiles.
Hot Tensile Deformation Behavior and Constitutive Models of GH3230 Superalloy Double-Sheet
Authors: Chen Yiqi , Li Hong , Zhang Song , Luo Jiao , Teng Junfei , Lv Yanlong , Li Miaoquan
Published: January 2023

In this paper, the hot tensile deformation of a GH3230 superalloy double-sheet was conducted under deformation temperatures ranging from 1123~1273 K and strain rates ranging from 0.001~0.2 s−1. The flow behavior of the GH3230 superalloy double-sheet was analyzed in detail. The hot tensile deformation process of the GH3230 superalloy double-sheet includes four stages of elastic deformation, strain hardening, steady state and fracture. The true stress decreases with the increasing deformation temperature and decreasing strain rate. The variation of the strain rate sensitivity index and strain hardening index with processing parameters were discussed. The average apparent activation energy for hot tensile deformation is 408.53 ± 46.96 kJ·mol−1. A combined Johnson-Cook and Hensel-Spittle model considering the couple effect of strain hardening, strain rate hardening and thermal softening was established to describe the hot tensile behavior of the GH3230 alloy double-sheet. Compared to Johnson-Cook model and Hensel-Spittle model, this model has the highest predicting accuracy. The average absolute relative error of true stress between the experimental and the predicted is only 2.35%.
Effect of Laser Peening on the Corrosion Properties of 304L Stainless Steel
Authors: Yoo Young-Ran , Choi Seung-Heon , Kim Young-Sik
Published: January 2023

Dry canisters used in nuclear power plants can be subject to localized corrosion, including stress corrosion cracking. External and residual tensile stress can facilitate the occurrence of stress corrosion cracking. Residual stress can arise from welding and plastic deformation. Mitigation methods of residual stress depend upon the energy used and include laser peening, ultrasonic peening, ultrasonic nanocrystal surface modification, shot peening, or water jet peening. Among these, laser peening technology irradiates a continuous laser beam on the surface of metals and alloys at short intervals to add compressive residual stress as a shock wave is caused. This research studied the effect of laser peening with/without a thin aluminum layer on the corrosion properties of welded 304L stainless steel. The intergranular corrosion rate of the laser-peened specimen was a little faster than the rate of the non-peened specimen. However, laser peening enhanced the polarization properties of the cross-section of 304L stainless steel, while the properties of the surface were reduced by laser peening. This behavior was discussed on the basis of the microstructure and residual stress.
Alternative Fillers in Asphalt Concrete Mixtures: Laboratory Investigation and Machine Learning Modeling towards Mechanical Performance Prediction
Authors: Tiwari Nitin , Rondinella Fabio , Satyam Neelima , Baldo Nicola
Published: January 2023

In recent years, due to the reduction in available natural resources, the attention of many researchers has been focused on the reuse of recycled materials and industrial waste in common engineering applications. This paper discusses the feasibility of using seven different materials as alternative fillers instead of ordinary Portland cement (OPC) in road pavement base layers: namely rice husk ash (RHA), brick dust (BD), marble dust (MD), stone dust (SD), fly ash (FA), limestone dust (LD), and silica fume (SF). To exclusively evaluate the effect that selected fillers had on the mechanical performance of asphalt mixtures, we carried out Marshall, indirect tensile strength, moisture susceptibility, and Cantabro abrasion loss tests on specimens in which only the filler type and its percentage varied while keeping constant all the remaining design parameters. Experimental findings showed that all mixtures, except those prepared with 4% RHA or MD, met the requirements of Indian standards with respect to air voids, Marshall stability and quotient. LD and SF mixtures provided slightly better mechanical strength and durability than OPC ones, proving they can be successfully recycled as filler in asphalt mixtures. Furthermore, a Machine Learning methodology based on laboratory results was developed. A decision tree Categorical Boosting approach allowed the main mechanical properties of the investigated mixtures to be predicted on the basis of the main compositional variables, with a mean Pearson correlation and a mean coefficient of determination equal to 0.9724 and 0.9374, respectively.
Forgotten Factors in Knowledge Conversion and Routines: A Fuzzy Analysis of Employee Knowledge Management in Exporting Companies in Boyacá
Authors: Blanco-Mesa Fabio , Vinchira Omar , Cuy Yesica
Published: January 2023

The department of Boyacá accounts for only 0.93% of national exports, which means that the participation of exporting companies in the region is low. One of the most important factors within these organizations is the knowledge of the collaborators, since it is an asset that contributes to the daily activities carried out within an organization. Hence, the objective of this research was to analyze the incidence of the forgotten factors in knowledge management through the conversion of knowledge and the routines of the personnel in Boyacá’s exporting companies, by means of causal analysis using fuzzy methodologies. The participants are exporting activity collaborators in the companies, who were consulted as sources of information for the Boyacá chamber of commerce. For the treatment, the forgotten effects theory, the experton method, and the adequacy coefficient are used. The information collected is processed using FuzzyLog software. The findings highlight that there are forgotten factors between the knowledge conversion and routines related to informal communication and social interactions. It is worth noting that it is important to carry out a more in-depth analysis of each of the individual knowledge spiral pillars in exporting companies in different regions of the country, focusing on social interactions (linguistic expression) and informal communication (electronic meetings).
A Review of Mathematical Models of Elasticity Theory Based on the Methods of Iterative Factorizations and Fictitious Components
Authors: Ushakov Andrey , Zagrebina Sophiya , Aliukov Sergei , Alabugin Anatoliy , Osintsev Konstantin
Published: January 2023

This review analyzes articles on mathematical modeling of elasticity theory using iterative factorizations and fictitious components. To carry out this study, various methods are developed, for example, an approximate analytical method of iterative factorizations for calculating the displacements of a rectangular plate, and a modified method of fictitious components for calculating the continuous displacement of plates. The performed calculations confirm the effectiveness of these methods. Descriptions of solutions to problems of elasticity theory and possible applications of the considered mathematical models and methods are given. An overview of the methods used to solve these problems is given. Particular attention is paid to problematic issues that arise in solving these problems. Techniques used to reduce complex problems to the solution of simple problems are given, for example, the lowering of the order of differential equations and the reduction of solutions in complex domains to solutions in a simple domain. For the first approach, iterative factorization methods are often used, and for the second, methods of the fictitious component type are often used. The main presentation in this review is focused on the approximate solution of elliptic boundary value problems. The works considered in the review raise questions about the development of methods in research on fictitious domains, fictitious components, and iterative factorizations.
Impulsive Control of Some Types of Nonlinear Systems Using a Set of Uncertain Control Matrices
Authors: Wu Keke , Onasanya Babatunde Oluwaseun , Cao Longzhou , Feng Yuming
Published: January 2023

So many real life problems ranging from medicine, agriculture, biology and finance are modelled by nonlinear systems. In this case, a chaotic nonlinear system is considered and, as opposed to solving Linear Matrix Inequality (LMI), which is the usual approach but cumbersome, a completely different approach was used. In some other cases, the computation of singular value of matrix was used but the method in this study needs not such. In addition, most models, if not all, concentrate on finding a control matrix J under some sufficient conditions. The problem is that only one such matrix J is provided. In reality, the actual control quantity may have a little deviation from the theoretical J. Hence, the study in this paper provides a set of infinite uncertain matrices Jα which are able to adapt to control the system under uncertain conditions. It turns out that this new method controls the system in shorter time with less computational complexities.
Preventive Maintenance of k-out-of-n System with Dependent Failures
Authors: Rykov Vladimir , Kochueva Olga
Published: January 2023

The paper investigates a model of a k-out-of-n system, the residual lifetime of which changes after failures of any of its components. The problem of a Preventive Maintenance (PM) organization as advice to the Decision Maker (DM) for such a system is considered. The purpose of this paper is to propose a mathematical model of the k-out-of-n system to support DM about PM. For most practical applications, it is usually possible to estimate the lifetime distribution parameters of the system components with limited accuracy (only one or two moments), which is why special attention is paid to the sensitivity analysis of the system reliability characteristics and decisions about PM to the shape of system components lifetime distributions. In the numerical examples, we consider the 3-out-of-6 model discussed in our previous works for two real systems. The novelty, significance, and features of this study consist of the following, after the failure of one of the system components, the load on all the others increases, which leads to a decrease in their residual lifetime. We model this situation with order statistics and study the quality of PM strategies with respect to the availability maximization criterion. At the same time, we are focusing on the study of the sensitivity of decision-making to the type of lifetime distribution of system components.
Thermoradiationally Modified Polytetrafluoroethylene as a Basis for Membrane Fabrication: Resistance to Hydrogen Penetration, the Effect of Ion Treatment on the Chemical Structure and Surface Morphology, Evaluation of the Track Radius
Authors: Moskvitin Lev Vladimirovich , Koshkina Ol’ga Alekseevna , Slesarenko Sergei Vital’evich , Arsentyev Mikhail Aleksandrovich , Trakhtenberg Leonid Izrailevich , Ryndya Sergei Mikhailovich , Magomedbekov Eldar Parpachevich , Smolyanskii Alexander Sergeevich
Published: January 2023

A study of the properties of thermoradiationally modified polytetrafluoroethylene and its importance for use as the basis of polymer membranes is presented. The hydrogen permeability of a TRM-PTFE film was studied in comparison with an original PTFE film, and showed a three-fold decrease in hydrogen permeability. Further, TRM-PTFE films were irradiated with accelerated Xe ions with an energy of 1 MeV with fluences from 1 × 108 to 1 × 1011. The changes induced by ion treatment were analyzed by infrared spectroscopy of disturbed total internal reflection (IR-ATR) and by atomic force microscopy (ASM). IR-ATR indicated the absence of destruction in the fluence range from 1 × 108 to 3 × 1010 cm−2 (in the area of isolated tracks) and the beginning of overlap of latent tracks on fluences from 3 × 1010 to 1 × 1011 cm−2. Topographic images with AFM showed layered lamellar structures that collapsed at a fluence of 108 cm−2. The destruction was accompanied by a decrease in roughness about seven times the size of the track core observed by the ASM method, fully corresponding to the value obtained on the basis of calculations using modeling in an SRIM program.
Association of Plasma Irisin Levels with Circulating Endothelial Microparticles (EMPs) and Endothelial Progenitor Cells (EPCs) in Children Born Prematurely
Authors: Markopoulou Panagiota , Koutroumpa Arsinoi , Mantzou Aimilia , Margeli Alexandra , Papanikolaou Eleni , Siahanidou Tania
Published: January 2023

Prematurity has been linked with endothelial dysfunction in later life. The purpose of this study was to evaluate the association between plasma irisin, an adipomyokine reported to protect the functional integrity of vascular endothelium, and circulating endothelial microparticles (EMPs) and endothelial progenitor cells (EPCs), consisting early biomarkers of endothelial dysfunction, in preterm-born children. We studied 131 prepubertal children; 61 preterm and 70 born at term (controls). Plasma irisin was determined by ELISA. Circulating CD62E(+), CD144(+) and CD31(+)/CD42b(-) EMPs, and CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs, were determined by flow cytometry. Body mass index, waist-to-hip ratio, neck circumference, systolic and diastolic blood pressure, and biochemical parameters (glucose, lipids, insulin, HOMA-IR) were also evaluated. Plasma irisin was significantly lower (p = 0.001), whereas circulating EMPs and EPCs were higher, in children born prematurely compared to controls. Irisin was recognized as independent predictor for CD144(+) and CD31(+)/CD42b(-) EMPs, CD34(+)/VEGFR-2(+)/CD45(-) and CD34(+)/VEGFR-2(+)/CD45dim EPCs in the total study population, and for CD31(+)/CD42b(-) EMPs in the preterm group. In conclusion, plasma irisin correlates independently with circulating EMP and EPC subpopulations in prepubertal children and in preterm-born ones. Further studies in children will potentially elucidate the link between irisin and the primary stages of prematurity-related endothelial dysfunction.
Legionnaires’ Disease in China Caused by Legionella pneumophila Corby
Authors: Xu Pei-Xing , Ren Hong-Yu , Li Ran , Jin Xiao-Jing , Gao Zhan-Cheng , Qin Tian
Published: January 2023

Legionella pneumophila is an intracellular pathogen causing pneumonia in humans. In February 2022, Legionnaires’ disease caused by L. pneumophila strain Corby in a patient with lung adenocarcinoma was identified for the first time in China. This paper includes the case report and phenotypic and genomic analysis of the Corby (ICDC) strain. Its biological characteristics were evaluated by antibiotic sensitivity testing and cytology experiments, and genomic analysis was performed to understand its genetic evolution. The patient’s clinical manifestations included cough, fever, pulmonary infiltration, and significantly decreased activity endurance. After empirical antimicrobial therapy, infection indicators decreased. The Corby (ICDC) strain was susceptible to nine antibiotics and exhibited strong intracellular proliferation ability. A phylogenetic tree showed that the Corby (ICDC) strain was closely related to the Corby strain, but under the pressure of a complex environment, its genome had undergone more rearrangement and inversion. The type IF CRISPR-Cas system was identified in its genome, and spacer analysis indicated that it had been invaded by several foreign plasmids, bacteria, and viruses during evolution. Legionnaires’ disease caused by L. pneumophila strain Corby may be ignored in China, and it is urgent to improve long-term monitoring and investigation of aquatic environments and patients with respiratory infections to prevent a large-scale outbreak of Legionnaires’ disease.