bluuebunny/crossref_metadata_2025 huggingface dataset:
Spike Protein Impairs Mitochondrial Function in Human Cardiomyocytes: Mechanisms Underlying Cardiac Injury in COVID-19
Authors: Huynh Tin Van , Rethi Lekha , Lee Ting-Wei , Higa Satoshi , Kao Yu-Hsun , Chen Yi-Jen
Published: March 2023

Background: COVID-19 has a major impact on cardiovascular diseases and may lead to myocarditis or cardiac failure. The clove-like spike (S) protein of SARS-CoV-2 facilitates its transmission and pathogenesis. Cardiac mitochondria produce energy for key heart functions. We hypothesized that S1 would directly impair the functions of cardiomyocyte mitochondria, thus causing cardiac dysfunction. Methods: Through the Seahorse Mito Stress Test and real-time ATP rate assays, we explored the mitochondrial bioenergetics in human cardiomyocytes (AC16). The cells were treated without (control) or with S1 (1 nM) for 24, 48, and 72 h and we observed the mitochondrial morphology using transmission electron microscopy and confocal fluorescence microscopy. Western blotting, XRhod-1, and MitoSOX Red staining were performed to evaluate the expression of proteins related to energetic metabolism and relevant signaling cascades, mitochondrial Ca2+ levels, and ROS production. Results: The 24 h S1 treatment increased ATP production and mitochondrial respiration by increasing the expression of fatty-acid-transporting regulators and inducing more negative mitochondrial membrane potential (Δψm). The 72 h S1 treatment decreased mitochondrial respiration rates and Δψm, but increased levels of reactive oxygen species (ROS), mCa2+, and intracellular Ca2+. Electron microscopy revealed increased mitochondrial fragmentation/fission in AC16 cells treated for 72 h. The effects of S1 on ATP production were completely blocked by neutralizing ACE2 but not CD147 antibodies, and were partly attenuated by Mitotempo (1 µM). Conclusion: S1 might impair mitochondrial function in human cardiomyocytes by altering Δψm, mCa2+ overload, ROS accumulation, and mitochondrial dynamics via ACE2.
Vesicular Zinc Modulates Cell Proliferation and Survival in the Developing Hippocampus
Authors: Fu Selena , Cho Ashley T. , Spanswick Simon C. , Dyck Richard H.
Published: March 2023

In the brain, vesicular zinc, which refers to a subset of zinc that is sequestered into synaptic vesicles by zinc transporter 3 (ZnT3), has extensive effects on neuronal signalling and modulation. Vesicular zinc-focused research has mainly been directed to its role in the hippocampus, particularly in adult neurogenesis. However, whether vesicular zinc is involved in modulating neurogenesis during the early postnatal period has been less studied. As a first step to understanding this, we used ZnT3 knockout (KO) mice, which lack ZnT3 and, thus, vesicular zinc, to evaluate cell proliferation at three different age points spanning postnatal development (P6, P14, and P28). The survival and the neuronal phenotype of these cells was also assessed in adulthood. We found that male ZnT3 KO mice exhibited lower rates of cell proliferation at P14, but a greater number of these cells survived to adulthood. Additionally, significantly more cells labelled on P6 survived to adulthood in male and female ZnT3 KO mice. We also found sex-dependent differences, whereby male mice showed higher levels of cell proliferation at P28, as well as higher levels of cell survival for P14-labelled cells, compared to female mice. However, female mice showed greater percentages of neuronal differentiation for P14-labelled cells. Finally, we found significant effects of age of BrdU injections on cell proliferation, survival, and neuronal differentiation. Collectively, our results suggest that the loss of vesicular zinc affects normal proliferation and survival of cells born at different age points during postnatal development and highlight prominent sex- and age-dependent differences. Our findings provide the foundation for future studies to further probe the role of vesicular zinc in the modulation of developmental neurogenesis.
Affect of the Scattering Asymmetry by Structural Element of Thermal- or Environmental-Barrier Ceramics on Subsurface Radiant Overheating
Authors: Merzlikin Vladimir , Safonov Evgeny , Kostyukov Andrey , Parshina Svetlana , Dokukina Anna
Published: March 2023

The problem of the formation and estimation of a thermoradiant and temperature field in ceramics Thermal- Environmental-Barrier Coatings (TBC/EBC) has been considered with complex heat transfer but under the influence of the penetrating intense radiant component. The authors proposed to analyze not only TBC but also EBC from the point of view of the optics of semitransparent scattering and absorbing media in the range of ~0.4–4 μm of external radiant action. This paradigm allows us to continue the study of ceramic fibers embedded in ceramic matrix CMCs (C/C, C/SiC, SiC/SiC) as a traditional class of opaque materials. However, at the same time, mullites, Al2O3/Al2O3 have been reviewed as a class of semitransparent elements for designing CMCs. The relevance of studying the effect of oriented fibers on the formation of thermoradiation and temperature fields in a semitransparent material was noted. Modeling the scattering asymmetry coefficient influence (scattering phase function) on the generation of the subsurface thermal radiation source was carried out. The methodology for calculating the thermoradiative field in a semitransparent medium (with relative absorption, scattering indexes, and scattering asymmetry coefficient) was used under a one-dimensional two-flux model as the first approximation for solving the radiative heat transfer equation. Calculations of temperature profiles in opaque and semitransparent ceramics were presented under heat load typical for the combustion chambers operating regime of diesel and gas turbine engines.
Selective Styrene Oxidation Catalyzed by Phosphate Modified Mesoporous Titanium Silicate
Authors: Chatterjee Rupak , Chowdhury Avik , Bhattacharjee Sudip , Bal Rajaram , Bhaumik Asim
Published: March 2023

Selective oxidation of organics over an efficient heterogeneous catalyst under mild liquid phase conditions is a very demanding chemical reaction. Herein, we first report the modification of the surface of mesoporous silica MCM-41 material by phosphate for the efficient incorporation of Ti(IV) in the silica framework to obtain highly ordered 2D hexagonal mesoporous material STP-1. STP-1 has been synthesized by using tetraethyl orthosilicate, triethyl phosphate, and titanium isopropoxide as Si, P, and Ti precursors, respectively, in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB) under hydrothermal conditions. The observed specific surface area and pore volume of STP-1 were 878 m2g−1 and 0.75 ccg−1, respectively. Mesoporous STP-1 has been thoroughly characterized by XRD, FT-IR, Raman spectroscopy, SEM, and TEM analyses. Titanium incorporation (Ti/Si = 0.006) was confirmed from the EDX analysis. This mesoporous STP-1 was used as a heterogeneous catalyst for the selective oxidation of styrene into benzaldehye in the presence of dilute aqueous H2O2 as an oxidizing agent. Various reaction parameters such as the reaction time, the reaction temperature, and the styrene/H2O2 molar ratio were systematically studied in this article. Under optimized reaction conditions, the selectivity of benzaldehyde could reach up to 93.8% from styrene over STP-1. Further, the importance of both titanium and phosphate in the synthesis of STP-1 for selective styrene oxidation was examined by comparing the catalytic result with only a phosphate-modified mesoporous silica material, and it suggests that both titanium and phosphate synergistically play an important role in the high selectivity of benzaldehyde in the liquid phase oxidation of styrene.
Surface-Enhanced Raman Spectroscopic Analysis of Flavoenzyme Cofactors: Guidance for Flavin-Related Bio- and Chemo- Sensors
Authors: Liu Yawen , Ma Hao , Zhao Junqi , Wang Jihong , Han Xiaoxia , Zhao Bing
Published: March 2023

Flavin mononucleotides (FMNs) and flavin adenine nucleotide (FAD) play vital roles in the electron-transfer processes in diverse enzymatic reactions. Owing to the isoalloxazine chromophore, flavins are easily detectable by surface-enhanced Raman spectroscopy (SERS), a surface-sensitive technique. However, the details of the adsorption of flavins on SERS-active materials have never been investigated. In this study, a comprehensive SERS analysis of flavins containing lumichrome and lumiflavin on silver nanoparticles was conducted. With the aid of density-functional-theory calculations, our results suggested that the flavin molecules were adsorbed on the silver nanoparticles via the N3 site of the isoalloxazine moiety, which had a stronger adsorption ability than the adenine moiety in the FAD. The SERS spectra of the flavins at different pH values also supported this conclusion. This study demonstrated the feasibility of SERS for the structural characterization of flavins, paving the way for the functional exploration of flavin-labeled detection sensors and flavoprotein researches.
Toxic Streptococcal Infection in Children: Report on Two Cases with Uncharacteristic Course of Scarlet Fever
Authors: Stencel-Gabriel Krystyna , Konwant Dawid , Szejnoga-Tułacz Karolina
Published: March 2023

Introduction: Scarlet fever is usually a mild childhood disease caused by type A streptococci. This disease is spread by droplets, mainly through direct contact with an infected person or the objects they have used. In pediatrics, these are significant risk factors for the transmission of infectious diseases. However, it is important to remember the possibility of serious complications in the course of scarlet fever. Aim: This paper provides a discussion of two pediatric cases in order to determine the possibilities of diagnosis, differentiation, and treatment of patients with severe, non-obvious courses of scarlet fever. Methods: The case reports of two patients hospitalized in a pediatric department due to Streptococcus pyogenes infection were examined. Results: The patients were admitted to the emergency room with symptoms not directly indicative of type A streptococcal infection, which required further diagnosis. Both patients complained of weakness at the time of presentation. They had an elevated temperature, were dehydrated during the course of gastroenteritis, and passed liquid stools without pathological admixtures. Further stages of diagnosis and treatment required hospitalization in the pediatric department. Therapeutic benefit from the implemented treatment was obtained, and the patients were discharged in good general condition with further recommendations. Conclusions: Medical history, which is often very detailed, can be the key to making the final diagnosis and can supplement the data collected on the basis of laboratory tests. Scarlet fever does not always occur with a mild course, and sometimes its course can be quite non-specific and may require a thorough diagnosis.
Exploring Intergroup Peer Exclusion: Validation of the Latency Social-Psychological Developmental Questionnaire (LSPD)
Authors: Fisher-Grafy Hanna , Meyer Sonya
Published: March 2023

Intergroup peer exclusion has been studied mainly from a pathological aspect. Currently, methods of diagnosis and treatment focus on this pathological point of view. Qualitative research has revealed that social intergroup peer exclusion has a role in the developmental task of the latency stage. The study’s main aim was to develop and validate a quick and easy quantitative questionnaire for use in a school setting that reflects the social developmental variables exposed in previous qualitative research. The 32-item Latency Social-Psychological Developmental questionnaire (LSPD) and the Loneliness and Social Dissatisfaction Questionnaire were administered to 20 Grade 4 and Grade 5 classes at four co-ed public elementary schools (N = 373 participants). Factor analysis revealed six developmental factors, and correlations were found between these factors and loneliness. The LSPD is a tool for assessing latency stage development among children who experienced exclusion as well as the developmental status of the entire class. The LSPD can assist in identifying specific development areas to focus on in treatment and intervention.
Esthetic Rehabilitation of Pediatric Patients Using Direct Bonding Technique—A Case Series Report
Authors: Elfadil Sittana , Nassar Hossam I. , Elbeshbeishy Rana Aly , Annamma Lovely M.
Published: March 2023

Pediatric esthetic dentistry is a sensitive technique, as children can be less cooperative; hence, minimal appointments are preferred. The most conservative treatment modality for anterior esthetic rehabilitation is using direct composite veneer restorations. In many instances, esthetic improvements using composite resin are the only possible option until the growth phase of the pediatric patient is complete. In this article, we present three different case scenarios in young teenagers with different treatment needs requiring esthetic restorations. The first case report is a patient with amelogenesis imperfecta, the second is with generalized spacing, and the third is with localized microdontia. All three patients were followed up for six months post direct composite veneering and were highly satisfied with their treatment outcomes, which boosted their self-confidence.
Effect of Atorvastatin on Angiogenesis-Related Genes VEGF-A, HGF and IGF-1 and the Modulation of PI3K/AKT/mTOR Transcripts in Bone-Marrow-Derived Mesenchymal Stem Cells
Authors: Adamičková Adriana , Chomaničová Nikola , Gažová Andrea , Maďarič Juraj , Červenák Zdenko , Valášková Simona , Adamička Matúš , Kyselovic Jan
Published: March 2023

Stem cell transplantation represents a unique therapeutic tool in tissue engineering and regenerative medicine. However, it was shown that the post-injection survival of stem cells is poor, warranting a more comprehensive understanding of activated regenerative pathways. Numerous studies indicate that statins improve the therapeutic efficacy of stem cells in regenerative medicine. In the present study, we investigated the effect of the most widely prescribed statin, atorvastatin, on the characteristics and properties of bone-marrow-derived mesenchymal stem cells (BM-MSCs) cultured in vitro. We found that atorvastatin did not decrease the viability of BM-MSCs, nor did it change the expression of MSC cell surface markers. Atorvastatin upregulated the mRNA expression levels of VEGF-A and HGF, whereas the mRNA expression level of IGF-1 was decreased. In addition, the PI3K/AKT signaling pathway was modulated by atorvastatin as indicated by the high mRNA expression levels of PI3K and AKT. Moreover, our data revealed the upregulation of mTOR mRNA levels; however, no change was observed in the BAX and BCL-2 transcripts. We propose that atorvastatin benefits BM-MSC treatment due to its ability to upregulate angiogenesis-related genes expression and transcripts of the PI3K/AKT/mTOR pathway.
Transcriptomic Establishment of Pig Macrophage Polarization Signatures
Authors: Li Jing , Yuan Teng , Zhang Anjing , Yang Peidong , He Li , Long Keren , Tang Chuang , Chen Li , Li Mingzhou , Lu Lu
Published: March 2023

Macrophages are the foremost controllers of innate and acquired immunity, playing important roles in tissue homeostasis, vasculogenesis, and congenital metabolism. In vitro macrophages are crucial models for understanding the regulatory mechanism of immune responses and the diagnosis or treatment of a variety of diseases. Pigs are the most important agricultural animals and valuable animal models for preclinical studies, but there is no unified method for porcine macrophage isolation and differentiation at present; no systematic study has compared porcine macrophages obtained by different methods. In the current study, we obtained two M1 macrophages (M1_IFNγ + LPS, and M1_GM-CSF) and two M2 macrophages (M2_IL4 + IL10, and M2_M-CSF), and compared the transcriptomic profiles between and within macrophage phenotypes. We observed the transcriptional differences either between or within phenotypes. Porcine M1 and M2 macrophages have consistent gene signatures with human and mouse macrophage phenotypes, respectively. Moreover, we performed GSEA analysis to attribute the prognostic value of our macrophage signatures in discriminating various pathogen infections. Our study provided a framework to guide the interrogation of macrophage phenotypes in the context of health and disease. The approach described here could be used to propose new biomarkers for diagnosis in diverse clinical settings including porcine reproductive and respiratory syndrome virus (PRRSV), African swine fever virus (ASFV), Toxoplasma gondii (T. gondii), porcine circovirus type 2 (PCV2), Haemophilus parasuis serovar 4 (HPS4), Mycoplasma hyopneumoniae (Mhp), Streptococcus suis serotype 2 (SS2), and LPS from Salmonella enterica serotype minnesota Re 595.
Beam-Truss Models to Simulate the Axial-Flexural-Torsional Performance of RC U-Shaped Wall Buildings
Authors: Hoult Ryan , Correia António A. , de Almeida João Pacheco
Published: March 2023

Reinforced concrete (RC) core walls are commonly used to provide buildings with lateral and torsional resistance against the actions of wind and earthquakes. In low-to-moderate seismic regions, it is not unusual to find a single peripheral core wall that alone should resist these actions, where the torsional (rotational) twist cannot be neglected. It has previously been difficult to have confidence in simulating the axial-flexure-torsion behavior of these RC core walls, primarily due to: (i) some types of modelling approaches being unable to appropriately account for the shear-flexural action, as well as torsional response; and (ii) the scarcity of experimental data, particularly for walls under torsional loads, which would be required to validate such models. In this research, beam-truss models (BTMs), which correspond to an interesting compromise between detailed modelling and practical applications, were used to simulate the in-plane and diagonal flexural response of RC U-shaped walls. Furthermore, the global torque-rotation results from a recent experimental wall test provided the evidence to further validate this powerful modelling technique. A case study building, comprising an RC U-shaped core wall structure with varying eccentricity values, was evaluated for an earthquake event with a 2475-year return period in the city of Melbourne, Australia, using the capacity spectrum method. Nonlinear static pushover analyses showed that, depending on the magnitude of torsion, the in-plane flexural strength and displacement capacity can be significantly reduced. The results from this research emphasize the importance of including torsional actions in the design and assessment of reinforced concrete buildings.
D-SPARC: Rapid Field Albedo Measurement
Authors: Sen Sushobhan , Roesler Jeffery
Published: March 2023

The albedo of surfaces in urban areas plays an important role in regulating the urban microclimate and needs to be measured. Artificial urban surfaces, e.g., pavements with lower albedo than natural surfaces such as grass or soil, are a key contributor to the Urban Heat Island (UHI) effect. However, widespread measurement of pavement albedo in the field remains challenging due to limited available daylight hours to record the measurements, the need for clear sky conditions, and slow data collection speed. A new portable system called Discrete SPectrAl RefleCtometer (D-SPARC) was developed to overcome these difficulties. D-SPARC was calibrated in the lab using 25 concrete specimens of known albedo and found to be accurate to within ±0.05, which is similar or better than recently developed aerial or satellite methods. The calibrated D-SPARC device was then used to acquire measurements on ten pavement sections during both the day and night and compared to the results from an albedometer. The RMSE during the day was 0.06 and during the night was 0.02. Each measurement with D-SPARC took about 4 min per test location as compared to 15 min with the albedometer. D-SPARC can be used to conveniently and rapidly measure pavement albedo over a road network with reasonable accuracy and minimal traffic disruption.
Microscale Templating of Materials across Electrospray Deposition Regimes
Authors: Grzenda Michael J. , Atzampou Maria , Samateh Alfusainey , Jitianu Andrei , Zahn Jeffrey D. , Singer Jonathan P.
Published: March 2023

Electrospray deposition (ESD) uses strong electric fields to produce generations of monodisperse droplets from solutions and dispersions that are driven toward grounded substrates. When soft materials are delivered, the behavior of the growing film depends on the film’s ability to dissipate charge, which is strongly tied to its mobility for dielectric materials. Accordingly, there exist three regimes of electrospray: electrowetting, charged melt, and self-limiting. In the self-limiting regime, it has been recently shown that the targeted nature of these sprays allows for corona-free 3D coating. While ESD patterning on the micron-scale has been studied for decades, most typically through the use of insulating masks, there has been no comparative study of this phenomenon across spray regimes. Here, we used test-patterns composed of gratings that range in both feature size (30–240 μm) and spacing (⅓x–9x) to compare materials across regimes. The sprayed patterns were scanned using a profilometer, and the density, average height, and specificity were extracted. From these results, it was demonstrated that material deposited in the self-limiting regime showed the highest uniformity and specificity on small features as compared to electrowetting and charged melt sprays. Self-limiting electrospray deposition is, therefore, the best suited for modification of prefabricated electrode patterns.
Interfacial Microstructure and Shear Behavior of the Copper/Q235 Steel/Copper Block Fabricated by Explosive Welding
Authors: Li Jiansheng , Xu Zuyuan , Zhao Yu , Jiang Wei , Qin Wenbo , Mao Qingzhong , Wei Yong , Wang Banglun
Published: March 2023

A copper/Q235 steel/copper composite block with excellent bonding interfaces was prepared by explosive welding which was a promising technique to fabricate laminates. The microstructure and mechanical properties of the interfaces were investigated via the tensile-shear test, optical microscope (OM), X-ray diffraction (XRD), scanning electron microscope (SEM), and electron back-scattered diffraction (EBSD). The results showed that the shear strength of the upper-interface and lower-interfaces of the welded copper/steel are higher than ~235 MPa and ~222 MPa, respectively. The specimens failed fully within the copper and not at the bonding interface. It was attributed to: (1) no cavities and cracks at the interface; (2) the interface formed a metallurgical bonding including numerous ultra-fine grains (UFGs) which can significantly improve the plastic deformation coordination at the interface and inhibit the generation of micro-cracks.
Prediction of Microstructure and Mechanical Properties of Atmospheric Plasma-Sprayed 8YSZ Thermal Barrier Coatings Using Hybrid Machine Learning Approaches
Authors: Zhu Han , Li Dongpeng , Yang Min , Ye Dongdong
Published: March 2023

The preparation of thermal barrier coatings (TBCs) is a complex process involving the integration of physics and chemistry, mainly involving the flight behavior and deposition behavior of molten particles. The service life and performance of the TBCs were determined by various factors, especially the preparation process parameters. In this work, to set up the quantitative characterization model between the preparation process parameters and the performance characteristic parameters, the ceramic powder particle size, spraying power and spraying distance were treated as the model input parameters, the characteristic parameters of microstructure properties represented by the porosity, circularity and Feret’s diameter and the mechanical property represented by the interfacial binding strength and macrohardness were treated as the model output. The typical back propagation (BP) model and extreme learning machine (ELM) model combined with flower pollination algorithm (FPA) optimization algorithm were employed for modeling analysis. To ensure the robustness of the obtained regression prediction model, the k-fold cross-validation method was employed to evaluate and analyze the regression prediction models. The results showed that the regression coefficient R value of the proposed FPA-ELM hybrid machine learning model was more than 0.94, the root-mean-square error (RMSE) was lower than 2 and showed better prediction accuracy and robustness. Finally, this work provided a novel method to optimize the TBCs preparation process, and was expected to improve the efficiency of TBCs preparation and characterization in the future.
Mechanical Properties and Corrosion Behavior of Dual-Filler-Epoxy-Coated Steel Rebar under a Corrosive Environment
Authors: Wang Xingyu , Cao Qi , Tang Fujian , Pan Hong , Chen Xi , Lin Zhibin
Published: March 2023

The deterioration of steel rebar in reinforced concrete is a major issue that reduces RC structures’ durability and structural integrity. Significant efforts have been devoted to developing high-performance coatings to provide efficient protection of the rebar, and one promising approach is to utilize nanofiller as additives to improve the performance of polymer resins. This study aimed to improve the corrosion resistance of steel rebar by applying an epoxy coating with graphene nanoplatelets (GNPs) and silica nanopowders (NSs) as additives. The corrosion behavior of nanocomposite-coated rebars was characterized via an electrochemical impedance spectroscopy (EIS) test, and salt spray exposure was utilized to evaluate the durability of the coated rebars. Investigation of abrasion resistance and mechanical properties of the coatings was conducted using the falling sand test and tensile coupon test. In addition, the nanocomposites were scanned by micro-CT to explore the effect of binary nanofillers on the intactness of the polymeric matrix. The GNP-NS hybrid filler reduced the void fraction to 0.002%, whereas the void fraction in pure epoxy was 0.07%. Significant reinforcement was found in the mechanical properties; the addition of GNP-NS hybrid filler increased the tensile strength to 37.1 MPa, a 56% increase compared to the pure epoxy. Additionally, the GNP-NS hybrid fillers have led to an improvement of 16% in the Young’s modulus. In terms of corrosion resistance, the Rc value of rebar coated with GNP-NS coating was about three times greater than the ones coated with a single-filler epoxy coating during the initial test, and this value remained undegraded after 200 hr of exposure. In contrast, the group containing hybrid fillers displayed the lowest thickness loss following abrasion testing, with a 74% reduction in thickness loss, showing the coating’s high abrasion resistance. Hence, the results reveal that GNP-NS hybrid fillers have superior wear resistance, mechanical capabilities, anticorrosion properties, and durability. This research provides valuable insights into developing and implementing high-performance polymeric material to protect steel rebars in concrete structures, therefore significantly increasing the sustainability of concrete structures.
Microbiological Deterioration of Epoxy Coating on Carbon Steel by Pseudomonas aeruginosa
Authors: Zhang Shuyuan , Zheng Huaibei , Chang Weiwei , Lou Yuntian , Qian Hongchang
Published: March 2023

Epoxy coating is a commonly used anticorrosive coating on metal surfaces. Pseudomonas aeruginosa has been reported to be able to accelerate the corrosion of metal materials, but its effect on the corrosion resistance of epoxy coatings is rarely reported. In this work, the accelerated deterioration of epoxy coating on carbon steel caused by marine Pseudomonas aeruginosa was investigated. The immersion tests of epoxy coatings in the sterile and P. aeruginosa-inoculated culture media with 100%, 10%, and 0% nutrients were performed. When the nutrient concentration was reduced, the number of P. aeruginosa cells attached to the coating surface was improved, and the coatings suffered more degradation under starvation conditions. The results of electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization measurements showed that the presence of P. aeruginosa promoted the degradation of epoxy coating, and the coating had lower low frequency impedance modulus and higher corrosion current density in the inoculated medium with starvation conditions. The results of Fourier transform infrared spectroscopy (FTIR) indicated that the peak intensities of C-O-C and C-O groups of coatings decreased as nutrient concentration dropped in the inoculated medium. It indicated that P. aeruginosa accelerated the degradation of epoxy coatings through destroying the C-O-C and C-O groups.
Comparison between an RSSI- and an MCPD-Based BLE Indoor Localization System
Authors: Cortesi Silvano , Vogt Christian , Magno Michele
Published: March 2023

IPS is a crucial technology that enables medical staff and hospital management to accurately locate and track persons or assets inside medical buildings. Among other technologies, readily available BLE can be exploited to achieve an energy-efficient and low-cost solution. This work presents the design, implementation and comparison of a RSSI-based and a MCPD-based indoor localization system. The implementation is based on a lightweight wkNN algorithm that processes RSSI and MCPD distance data from connection-less BLE Beacons. The designed hardware and firmware are implemented around the state-of-the-art SoC for BLE, the nRF5340 from Nordic Semiconductor. Experimental evaluation with real-time data processing has been evaluated and presented in a 7.3 m × 8.9 m room with furniture and six beacon nodes. The experimental results on randomly chosen validation points within the room show an average error of only 0.50 m for the MCPD approach, whereas the RSSI approach achieved an error of 1.39 m.
End-to-End Delay Bound Analysis for VR and Industrial IoE Traffic Flows under Different Scheduling Policies in a 6G Network
Authors: Picano Benedetta , Fantacci Romano
Published: March 2023

Next-generation networks are expected to handle a wide variety of internet of everything (IoE) services, notably including virtual reality (VR) for smart industrial-oriented applications. VR for industrial environments subtends strict quality of service constraints, requiring sixth-generation terahertz communications to be satisfied. In such an environment, an additional important issue is trying to get high utilization of network and computing resources. This implies identifying efficient access techniques and methodologies to increase bandwidth utilization and enable flows related to services, with different service requirements, to coexist on the same computation node. Towards this goal, this paper addresses the problem of coexistence of the traffic flows related to different services with given delay requirements, on the same computation node arranged to execute flow processing. In such a context, a theoretical comprehensive performance analysis, to the best of the authors’ knowledge, is still missing in the literature. As a consequence, this lack strongly limits the possibility of fully capturing the performance advantages of computation node sharing among different traffic flows, i.e., services. The proposed analysis aims to give a measure of the ability of the system in accomplishing services before the expiration of corresponding deadlines. The integration of martingale bounds within the stochastic network calculus tool is provided, assuming both the first-in–first-out and the earliest deadline first scheduling policies. Finally, the validity of the analysis proposed is confirmed by the tightness emerging from the comparison between analytical predictions and simulation results.
Synthesis, Characterization, and Antibacterial Assessment (Synergism) of Silver Nanoparticles Prepared with Stem Bark Extract of Sterculia diversifolia
Authors: Rabbi Fazle , Ahmad Imad , Nisar Amna , Rauf Abdur , Alshammari Abdulrahman , Alharbi Metab , Suleria Hafiz Ansar Rasul
Published: March 2023

Microbial infections present a challenging arena to the modern world. Traditional antibiotics are now familiar to microbes. To counter this microbial familiarity, a novel approach is a nanoparticle-based drug delivery system that exhibits promising results and overcomes these problems. This study was conducted to explore the efficacy of silver nanoparticles (AgNPs) by utilizing stem bark extract of Sterculia diversifolia followed by physicochemical characterization including ultraviolet-visible spectrophotometry (UV-Vis), X-ray diffractometer (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier-transform infrared spectroscopy. The UV-Vis characteristic spectral peak was recorded at 430 nm. XRD confirmed the crystalline structure of AgNPs, while FTIR confirmed phytochemicals in their capping, stabilization, and synthesis of AgNPs. SEM devised the particle size range of 100 nm at 30,000× magnification. TEM showed nanoparticles morphology, which is spherical in nature, while obtained nanoparticles were 100 nm in size. The antibacterial activity of synthesized NPs showed significant action against S. aureus and P. aeruginosa. Similarly, crude extract and n-hexane fraction showed maximum zone of inhibition. Promising results suggest that stem bark extract AgNPs of Sterculia diversifolia can be studied further for microbial mechanisms as well as formulation-based studies.
kHz, 10s TW, Femtosecond Source Based on Yb:YAG Thin Disk Laser Pumped OPCPA of Low Quantum Defect
Authors: Liu Keyang , Liu Xin , Li Jinhui , Wang Hushan , Wang Yishan , Zhao Wei , Cao Huabao , Fu Yuxi
Published: March 2023

We propose to obtain kHz, 10s TW, femtosecond sources through optical parametric chirped pulse amplification (OPCPA) pumped by Yb:YAG thin disk lasers. The final amplifiers of the OPCPA are based on LGS (LiGaS2) crystals with wide transparent range. To suppress the quantum defect for high efficiency, the final amplifiers are designed such that the wavelength of the signal is set very close to 1.03 μm, while the idler spectra span from 4–8 μm. Multiple crystals with different phase-matching configuration can be employed for the amplification of different spectral regions to support broadband pulse amplification. According to the numerical simulations, the pulse duration from Yb:YAG lasers can be shortened to 20–30 fs pulse with efficiency beyond 60%. This technique is energy scalable with the size of the LGS crystal size and can support a 26 TW pulse with current available LGS. The output pulses are ideal drivers for secondary light and particle source generation.
Crystallographic, Structural, and Electrical Properties of W6+ Substituted with Mo6+ in Crystalline Phases such as TTB Structure
Authors: Es-soufi Hicham , Sayyed M. I. , Almuqrin Aljawhara H. , Rajesh Raman , Lima Alan Rogerio Ferreira , Bih Hssain , Bih Lahcen
Published: March 2023

Owing to their low dielectric loss and high permittivity values, dielectric ceramics have garnered a lot of interest from the scientific and industrial sectors. These properties allow for their downsizing and use in a variety of electronic circuits. This present work focuses on the impact of the substitution of W6+ with Mo6+ on the structural and dielectric features of the crystalline phases in a similar TTB structure within the Ba0.54Na0.46Nb1.29W(0.37−x)MoxO5 system, with 0 ≤ x ≤ 0.33 mol%. These crystalline phases were elaborated using the conventional solid-state reaction method and analyzed with XRD, Raman, and dielectric techniques. The Rietveld refinement method showed that all these phases are characterized by tetragonal structure and the P4bm space group. The Raman spectra corresponded well to a TTB-like structure, and all the bands were assigned. The dielectric measurements of the prepared ceramic samples facilitated the determination of their phase transition temperature (Tc) and the dielectric responses. This investigation focused on determining dielectric permittivity (ε′) and its correlation with increases in MoO3 content in the ceramic structure.
Research on the Microstructure and Properties of a Flux-Cored Wire Gas-Shielded Welded Joint of A710 Low-Alloy High-Strength Steel
Authors: Wang Xing , Yang Zhibin , Du Lingzhi
Published: March 2023

In this study, a 16 mm thick A710 low-alloy high-strength steel was welded by using flux-cored wire gas-shielded welding with an E81T1-Ni1M flux-cored wire. The microstructure characteristics and mechanical properties of the joints were systematically studied. The results showed that the joint was well formed without obvious welding defects. The center of the weld was mainly needle-like ferrite, the coarse grain area was mainly slat-like and granular bainite, and the fine grain area was mainly ferrite and pearlite. The lowest hardness in the weld area was the weakest area of the joint. The average tensile strength of the joint was 650 MPa, reaching 95% of the base metal; the samples were all fractured in the weld area, and the fracture morphology showed typical plastic fracture characteristics. The low-temperature (−40 °C) impact energy of the joint weld area and the heat-affected zone were 71 J and 253 J; the fracture morphology was characterized by a ductile–brittle mixed fracture, and the ductile area of the specimen fracture in the heat-affected zone was larger. The bending performance was good. Under the specified life of 2 × 106 cycles; the median fatigue limit and the safety fatigue limit were 520 MPa and 492 MPa, and the fatigue cracks germinated on the surface of the priming weld.
A Review of Condensation Frosting—Mechanisms and Promising Solutions
Authors: Gu Tian , Zhao Yugang , Liu Yusheng , Wang Dongmin
Published: March 2023

Icing in the form of condensation frosting occurs ubiquitously in our daily life and numerous industrial applications. As the frost layer mostly comprises mixed microscopic dendrites and discrete air pockets, condensation frosting manifests a thick porous media and thus catastrophically compromises the heat transfer efficiency of HVAC systems. Despite being a popular research topic for centuries, a few unprecedented advances in the study of condensation frosting have been only achieved very recently, such as the revealing of new features in the incipient stages of frost formation, which used to be too fast or too small to capture, and new anti-/de-frosting techniques have been developed based on the revealed physics. This work provides a comprehensive, up-to-date review of condensation frosting, with an emphasis placed on progress in the very latest decade. Fundamentals of condensation frosting, including condensation nucleation, coalescence and growth of the condensed drops, icing nucleation, formation of frost halos, freezing propagation via ice bridging, and lastly densification and fully developed frost layers, are introduced chronologically as what occurs. A summary of recent engineering efforts to alleviate the negative impacts of condensation frosting, referred to as anti-/de-frosting techniques, is also presented. The results of these studies can greatly enlighten the existing understanding of condensation frosting and, meanwhile, benefit the development of new anti-/de- frosting methods for numerous application backgrounds.
Diversity of Parasitic Animals in Hypersaline Waters: A Review
Authors: Kornyychuk Yuliya , Anufriieva Elena , Shadrin Nickolai
Published: March 2023

Hypersaline waters are unique polyextreme habitats, where the salinity limits species richness. There are main patterns of a relationship between salinity and the species richness of free-living aquatic animals, but for parasitic organisms, general regularities have not yet been established. There are quite numerous data on parasites in hypersaline waters worldwide; however, they have not been summarized before. This review tries to fill this gap by summarizing the available data. All parasites, 85 species and forms, found in hypersaline waters belong to five phyla: Platyhelminthes, Nematoda, Acanthocephala, Cnidaria, and Arthropoda. Platyhelminthes are the most diverse phylum with the highest species richness in class Cestoda. Most species were noted in hypersaline waters with a salinity of no more than 100 g·L−1. The total number of parasitic species decreases exponentially with an increase in salinity. The number of free-living animal species inhabiting waters with a salinity from 35 to 210 g·L−1 is approximately 12 times higher than that of parasitic ones in all intervals of this salinity range. Salinity influences parasite richness and composition in two ways—directly and through the availability of hosts. Free-living crustaceans were hosts of most parasite species in hypersaline waters. Artemia spp., the most halotolerant animals, are an intermediate host for 22 species and unidentified forms of parasites.
Groundwater Amphipods of the Hyporheic Interstitial: A Case Study from Luxembourg and The Greater Region
Authors: Weber Dieter , Weigand Alexander M.
Published: March 2023

Hyporheic interstitials are ecologically dynamic and often neglected aquatic environments. In this study, groundwater amphipods (Niphargidae, Pseudoniphargidae and Crangonyctidae) were sampled in hyporheic interstitials throughout Luxembourg and The Greater Region and specimens were analyzed by DNA barcoding. Sites characterized by gravel or coarse sand and high flow velocities of incoming water were the most species- and specimen-rich. A total of 11 species were detected, of which the Niphargus aquilex lineage EF of the N. aquilex cryptic species complex and juveniles of N. schellenbergi dominated the data set, but an unknown lineage of the N. aquilex-complex was also found. Some regions appeared to be devoid of groundwater amphipods. We hypothesize that underlying sandstone formations resulting in low sediment porosity may prevent physical colonization, but also that historical water pollution may have a long-lasting effect, either through the persistence of contaminants in the sediment or low recolonization rates of affected populations. In summary, our approach expanded regional species inventories, confirmed known occurrences, and validated previously questionable or historical morphology-based detections. In addition, the collection of absence data provided valuable insights into local extinctions. Finally, DNA-based distribution data are needed to gather information on the ecological affinities of groundwater amphipods to understudied hyporheic interstitial environments.
Are Roadkills Density-Dependent? Case Study of the Barn Owl (Tyto alba)
Authors: Meyrom Kobi , Yosef Reuven , Charter Motti
Published: March 2023

Even though birds are some of the most common road-killed animals, it remains to be determined whether avian roadkills are related to breeding numbers and breeding success, mainly due to a lack of study areas that monitor breeding populations and roadkills. We studied whether barn owl breeding numbers and breeding success are related to roadkills. We monitored yearly barn owl breeding numbers (2174 breeding attempts and 1682 adults ringed) and breeding success (9380 nestlings ringed) and monitored 95 km of roads weekly for roadkills from 2009 to 2017 in the Beit Shean and Emek Yizreel Valleys, Israel. During the study period, we documented 1073 road-killed barn owls, of which 328 were ring recoveries. The highest mortality occurred between July to September, coinciding with the barn owl post-fledging period. The number of breeding pairs and the number of nestlings ringed were positively related to the total number of barn owl roadkill, the proportion of roadkill ring recoveries, and the proportion of ring recovered roadkills in the first year of their life. First-year owls represent the majority of ringed owls, accounting for 64.6%, while adult owls compose 35.4%. Notably, a substantial fraction of adult ring recoveries, encompassing 67.2%, may pertain to floaters since we did not observe these individuals as breeding adults. Even though more females were found as roadkill ring recoveries, the proportion of male/female ring recoveries from roadkills was similar to that of adults ringed at the nest boxes. This study is the first that shows that barn owl roadkills are density-dependent and demonstrate the importance of monitoring breeding and population numbers in roadkill studies.
A New Genus and Species of †Cladocyclidae (Teleostei: †Ichthyodectiformes) from the Lower Cretaceous “Batateira Beds”, Barbalha Formation, Araripe Basin: The First Vertebrate Record in a Still Poorly Explored Fossil Site
Authors: de Mayrinck Diogo , Ribeiro Alexandre Cunha , Assine Mario Luis , Spigolon André Luis Durante
Published: March 2023

The Mesozoic Teleostei †Ichthyodectiformes presents a widespread distribution in marine brackish and freshwater deposits worldwide. The Brazilian fossil record of this group is represented by five nominal genera distributed exclusively in the sedimentary basins of Northeast Brazil (cf. Parnaíba, Sergipe-Alagoas, Recôncavo, Tucano, and Araripe). In the Araripe basin, the unique representative of the order is †Cladocyclus gardneri, restricted to the Crato and Romualdo Formations. Recent collecting efforts carried out in the Araripe Basin led to the discovery of two specimens of †Cladocyclidae. Based on the comparison with the known Brazilian taxa, we conclude that this new record represents a new genus and species of this clade. †Cladocynodon araripensis represents the first vertebrate described from the dark shales of the “Batateira Beds” of the Barbalha Formation and differs from the other †Cladocyclidae by the presence of hypertrophied bony fangs at the anterior region of the dentary, with other relatively small true teeth abruptly reduced posteriorly, and by presenting premaxillary and maxillary teeth significantly reduced in size. †Cladocynodon araripensis increases the anatomic diversity and temporal range of †Cladocyclidae in Gondwana.
Morphological and Behavioral Adaptations of Silk-Lovers (Plokiophilidae: Embiophila) for Their Lifestyle in the Silk Domiciles of Webspinners (Embioptera)
Authors: Büscher Thies H. , Harper J. René , Sripada Neeraja , Gorb Stanislav N. , Edgerly Janice S. , Büsse Sebastian
Published: March 2023

The diversity of true bugs gave rise to various lifestyles, including gaining advantage from other organisms. Plokiophilidae are cimicomorphan bugs that live in the silk constructions of other arthropods. One group, Embiophila, exclusively settles in the silk colonies of webspinners (Embioptera). We investigated the lifestyle of Embiophila using microscopy to study the micromorphology and material composition of the leg cuticle, choice assays and retention time measurements based on different characteristics of the embiopteran galleries and tilting experiments with different substrates to quantify the attachment performance of the bugs. Embiophila neither explicitly preferred embiopteran presence, nor required silk for locomotion, but the bugs preferred fibrous substrates during the choice experiments. The hairy attachment pad on the tibia showed the best attachment performance on substrates, with an asperity size of 1 µm. Additionally, very rough substrates enabled strong attachment, likely due to the use of claws. Our findings suggest that Embiophila settle in galleries of webspinners to benefit from the shelter against weather and predators and to feed on mites and other intruders. The combination of behavioral and functional morphological experiments enables insights into the life history of these silk-associated bugs, which would be highly challenging in the field due to the minute size and specialized lifestyle of Embiophila.