bluuebunny/crossref_metadata_2025 huggingface dataset:
Stratigraphy of Fresco Paintings: A New Approach with Photoacoustic and SORS Imaging
Authors: Pisu Francesca A. , Chiriu Daniele , Klironomou Evgenia , Zacharakis Giannis , Tserevelakis George J.
Published: January 2023

Photoacoustic (PA) imaging is a novel, powerful diagnostic technique utilized in different research fields. In particular, during recent years it has found several applications in Cultural Heritage (CH) diagnostics. PA imaging can be realized in transmittance or epi-illumination (reflectance) modes, obtaining variable levels of contrast and spatial resolution. In this work, we confirmed the applicability of the PA technique as a powerful tool for the imaging of one of the most challenging artwork objects, namely fresco wall paints, to obtain precise stratigraphic profiles in different layered fresco samples. In this regard, we studied some multi-layered fragments of the vault of San Giuseppe Church in Cagliari (1870 AD) and some mock-ups realized specifically to test the potentiality of this technique. Due to complex structures of the frescoes, we used the Spatially Off-set Raman Spectroscopy (SORS) technique to provide complementary information. The experimental results were in agreement for both techniques, even for the three-layered complex structure, and were confirmed with Scanning Electron Microscopy (SEM) analysis of cross-sections. The combined use of these two techniques proved useful to investigate detailed hidden information on the fresco samples.
Numerical Study on Lateral Response of Offshore Monopile in Sand under Local Scouring Conditions
Authors: Shen Jiayi , Ge Chang , Zhan Yide , Ye Zhaoyi , Zhang Qiang , Chen Jiawang
Published: January 2023

Currently, p-y models have been broadly adopted for estimating the lateral bearing capacity of large-diameter monopiles in offshore engineering. However, the existing p-y curves cannot reflect the effect of pile diameter D on the lateral response of monopiles under local scouring conditions. In order to extend the existing p-y model to a large-diameter pile, a well-calibrated three-dimensional pile-soil model performed by ABAQUS is used to study the effect of the pile diameter D on the ultimate soil resistance P and the initial stiffness k of the Lin’s p-y model. Based on the numerical simulation results, two diameter-related parameters A and B, which represent the relationships between the ultimate soil resistance and the initial stiffness obtained by the numerical model and the Lin’s p-y model, respectively, are proposed and introduced into the Lin’s p-y model to present a modified p-y model. The comparison results show that the proposed modified p-y model is capable of providing a better estimation of the lateral response of large-diameter monopiles than the existing p-y model under a scouring condition.
Identification and Characterization of Colletotrichum Species Causing Sorghum Anthracnose in Kenya and Screening of Sorghum Germplasm for Resistance to Anthracnose
Authors: Koima Irene Njeri , Kilalo Dora Chao , Orek Charles O. , Wagacha John Maina , Nyaboga Evans N.
Published: January 2023

Anthracnose caused by Colletotrichum species is one of the most destructive fungal diseases of sorghum with annual yield losses of up to 100%. Although the resistance to anthracnose has been identified elsewhere, the usefulness of the resistance loci differs depending on the pathogen species and pathotypes. Accurate species identification of the disease-causing fungal pathogens is essential for developing and implementing suitable management strategies. The use of host resistance is the most effective strategy of anthracnose management and therefore identification of sources for resistance against unique pathogen pathotypes is fundamental. The aims of this study were to identify and characterize Colletotrichum species associated with sorghum anthracnose and screen sorghum germplasm for resistance to anthracnose. Symptomatic sorghum leaf samples were collected from smallholder farmers in lower eastern Kenya and used for the isolation, identification and characterization of Colletotrichum species using morpho-cultural and phylogenetic analyses with the sequences of the rDNA internal transcribed spacer (ITS) region. Pathogenicity tests of the seven fungal isolates showed that there were no significant differences in the pathogenicity on host plants. The fungal isolates were variable in cultural and morphological characters such as colony type and color, colony diameter, mycelia growth and hyaline. The phenotypic characters observed were useful in the identification of the genus Colletotrichum and not the species. Based on the sequence and phylogenetic analysis of ITS, Colletotrichum sublineola was revealed to be associated with anthracnose on sorghum. Germplasm screening for resistance to anthracnose showed differential reactions of sorghum genotypes to anthracnose under greenhouse and field conditions. The results revealed four resistant genotypes and ten susceptible genotypes against Colletotrichum sublineola. Significant (p ≤ 0.05) differences were observed in grain weight, grain yield, weight of 100 seeds and harvest index among the tested sorghum genotypes. The present study indicated that the Kenyan accessions could be an important source of resistance to anthracnose. The findings from this study provide a platform towards devising efficient disease control strategies and resistance breeding.
Energy Crisis Risk Mitigation through Nuclear Power and RES as Alternative Solutions towards Self-Sufficiency
Authors: Halkos George , Zisiadou Argyro
Published: January 2023

This paper reviews the case of nuclear energy. Currently, the worldworld is facing one of the greatest energy crises due to the Russo-Ukrainian war. This conflict has lead to limited sources of gas, causing a dramatic decrease in energy supply, leading to emerging energy crisis risks. This is one on the main purposes of reviewing nuclear energy as a possible energy alternative in the future. Apart from presenting the basis of nuclear energy and nuclear reactors, we attempt to compare this source of electricity with other renewable energy forms, such as solar, wind and hydroelectric power. Furthermore, we illustrate the benefits and drawbacks that have been observed regarding nuclear power as well as its contribution to economic growth and the impact it has had on the environment. It has been said that, with the use of nuclear power, air pollution will be reduced because of the elimination of greenhouse gases. However, nuclear power, apart from the final product, generates waste that in this case is radioactive, meaning that the management and disposal techniques are of the utmost importance. Of course, unfortunate events that involved nuclear power do exist and are unfortunately engraved in our memories. Both the nuclear accidents, such as Three Mile Island, Chernobyl and Fukushima, and nuclear weapons usage by military forces, the well-known atomic bombing of Hiroshima and Nagasaki, bring great controversy regarding the adaptation of nuclear power. As is presented in the paper, since the beginning of the new millennium the scheme of energy production and electricity production appears to have changed drastically. By using available data reported by BR, we illustrated that the production of energy and electricity has increased over the last 22 years (2000–2021) due to excessive demand; however, what is more important to mention is the share of both electricity and energy derived from renewable forms such as solar, wind and hydroelectric power. It is shown that more and more countries adopt those sources of energy than did in previous decades. It is crucial to note that it is not the science that causes catastrophic events, but rather the errors of humans.
Spreading Behavior of Single Oil Droplet Impacting Surface with/without a Thin Liquid Film
Authors: Liang He , Yang Peiyi , Wang Wenzhong , Liu Yanfei , Ge Xiangyu , Tong Baohong
Published: January 2023

When oil droplets impact a solid surface for oil-air lubrication, they may spread out to produce a thin oil layer on the surface, which serves as a significant source of lubrication. A test rig was constructed in this research to observe the spreading behavior of oil droplets impacting surfaces from both frontal and lateral views. From the frontal view, laser-induced fluorescence techniques are used to measure the thickness of the oil layer quantitatively during the spreading of oil droplets. While the lateral view can observe the shape evolution of the droplets. Oil droplet spreading patterns on the sheet with dry surfaces and with different thin liquid film thicknesses were studied, and the effect of viscosity and the thickness of the thin liquid film on spreading radius and spreading thickness is considered. The experimental findings demonstrate that the maximum spreading factor, the spreading central layer thickness, and the apparentness of retraction all increase as viscosity increases. The retraction is obviously impacted by thin liquid films, and the retraction weakens as the thin liquid film thickness increases.
Methyl 5′-Chloro-8-formyl-5-hydroxy-1′,3′,3′-trimethyl-spiro-[chromene-2,2′-indoline]-6-carboxylate
Authors: Ozhogin Ilya V. , Pugachev Artem D. , Kozlenko Anastasia S. , Rostovtseva Irina A. , Makarova Nadezhda I. , Borodkin Gennady S. , El-Sewify Islam M. , Metelitsa Anatoly V. , Lukyanov Boris S.
Published: January 2023

Spiropyrans modified with reactive polyfunctional substituents are of great interest as building blocks for the creation of various smart systems with controllable properties for materials science and biomedicine. In this study, a new highly modified spiropyran of the indoline series, methyl 5′-chloro-8-formyl-5-hydroxy-1′,3′,3′-trimethyl-spiro[chromene-2,2′-indoline]-6-carboxylate, was obtained via the cyclocondensation reaction from 5-chloro-1,2,3,3-tetramethyl-3H-indolium perchlorate and methyl 3,5-diformyl-2,4-dihydroxy-benzoate. The molecular structure of the target compound was confirmed by 1H, 13C NMR, and IR spectroscopy, as well as LC/MS and elemental analysis. Photochemical studies revealed photochromic activity for the obtained spiropyran at room temperature. The photoinduced merocyanine form demonstrated an enhanced lifetime and fluorescent properties in the red region of the spectrum.
Efficient Propylene Carbonate Synthesis from Urea and Propylene Glycol over Calcium Oxide–Magnesium Oxide Catalysts
Authors: Dang Kavisha , Kumar Navneet , Srivastava Vimal Chandra , Park Jinsub , Naushad Mu.
Published: January 2023

A series of calcium oxide–magnesium oxide (CaO–MgO) catalysts were prepared under the effects of different precipitating agents and using varied Mg/Ca ratios. The physiochemical characteristics of the prepared catalysts were analyzed using XRD, FE-SEM, BET, FTIR, and TG/DTA techniques. Quantification of basic active sites present on the surface of the CaO–MgO catalysts was carried out using the Hammett indicator method. The as-prepared mixed oxide samples were tested for propylene carbonate (PC) synthesis through the alcoholysis of urea with propylene glycol (PG). The effects of the catalyst composition, catalyst dose, reaction temperature, and contact time on the PC yield and selectivity were investigated. The maximum PC yield of 96%, with high PC selectivity of 99% and a urea conversion rate of 96%, was attained at 160 °C using CaO–MgO catalysts prepared using a Mg/Ca ratio of 1 and Na2CO3 as a precipitating agent. The best-performing catalysts also exhibited good reusability without any significant loss in PC selectivity. It is expected that the present study will provide useful information on the suitability of different precipitating agents with respect to the catalytic properties of the oxides of Ca and Mg and their application in the synthesis of organic carbonates.
Mechanical Properties of a Bone-like Bioceramic–Epoxy-Based Composite Material with Nanocellulose Fibers
Authors: Kim Young-Seong , Baek Jin Woo , Jin Zhengyun , Jeon Hee Chang , Han Min-Woo , Lim Joong Yeon
Published: January 2023

Several composite materials are being investigated as reinforcement fillers for surgery simulations. This study presents an artificial composite material with properties similar to those of the human bone, which may be used in surgery simulations. Moreover, considering the potential toxicity of debris generated during sawing, a safe epoxy-based composite material was synthesized using cellulose nanocrystals (CNCs) and bioceramics (i.e., hydroxyapatite, Yttria stabilized zirconia oxide, Zirconia oxide), which were used to mimic the stiffness of human bone. To examine the change in mechanical properties according to the composition, 1, 3, and 5 wt% of CNCs were mixed with 5 wt% of the bioceramics. When CNCs were added at 1 wt%, there was a confirmed change in the non-linear stiffness and ductility. The CNC-added specimen fractured when forming a nano-network around the local CNCs during curing. In contrast, the specimen without CNCs was more densely structured, and combined to form a network of all specimens such that a plastic region could exist. Thus, this study successfully manufactured a material that could mimic longitudinal and transverse characteristics similar to those of real human bone, as well as exhibit mechanical properties such as strength and stiffness. Bioceramics are harmless to the human body, and can be used by controlling the added quantity of CNCs. We expect that this material will be suitable for use in surgery simulations.
Synthesis of RGO/Cu@ FeAl2O4 Composites and Its Applications in Electromagnetic Microwave Absorption Coatings
Authors: Chu Zhenhua , Deng Wenxing , Xu Jingxiang , Wang Fang , Zhang Zheng , Hu Qingsong
Published: January 2023

In order to satisfy the requirements of wide frequency bands, the lightweight and strong absorption for the electromagnetic wave absorbing materials, a uniform mixture of FeAl2O4 with RGO/Cu (reduction graphene oxide, RGO) was obtained by the mechanical mixing method, and composite coating was obtained by plasma spraying. The addition of RGO/Cu into FeAl2O4 is conducive to improve the dielectric properties and the impedance matching performance of spinel. When the RGO/Cu composite powders are doped by 10 wt.%, the reflection loss at 15 GHz is −16 dB and the absorption bandwidth is 2 GHz, indicating that the composite material has potential application value in the field of high-frequency wave absorption. The research on the electromagnetic wave absorption mechanism shows that its superior wave absorption performance is determined by the synergistic effect of multiple loss mechanisms such as interfacial polarization, dipole relaxation, natural resonance, exchange resonance, and eddy current loss.
CeO2-rGO Composites for Photocatalytic H2 Evolution by Glycerol Photoreforming
Authors: Balsamo Stefano Andrea , La Greca Eleonora , Calà Pizzapilo Marta , Sciré Salvatore , Fiorenza Roberto
Published: January 2023

The interaction between CeO2-GO or CeO2-rGO and gold as co-catalysts were here investigated for solar H2 production by photoreforming of glycerol. The materials were prepared by a solar photoreduction/deposition method, where in addition to the activation of CeO2 the excited electrons were able to reduce the gold precursor to metallic gold and the GO into rGO. The presence of gold was fundamental to boost the H2 production, whereas the GO or the rGO extended the visible-light activity of cerium oxide (as confirmed by UV-DRS). Furthermore, the strong interaction between CeO2 and Au (verified by XPS and TEM) led to good stability of the CeO2-rGO-Au sample with the evolved H2 that increased during five consecutive runs of glycerol photoreforming. This catalytic behaviour was ascribed to the progressive reduction of GO into rGO, as shown by Raman measurements of the photocatalytic runs. The good charge carrier separation obtained with the CeO2-rGO-Au system allowed the simultaneous production of H2 and reduction of GO in the course of the photoreforming reaction. These peculiar features exhibited by these unconventional photocatalysts are promising to propose new solar-light-driven photocatalysts for green hydrogen production.
A Novel Approach to Visualize Liquid Aluminum Flow to Advance Casting Science
Authors: Bate Casey , King Philip , Sim Jay , Manogharan Guha
Published: January 2023

Turbulent filling of molten metal in sand-casting leads to bi-films, porosity and oxide inclusions which results in poor mechanical properties and high scrap rate of sand castings. Hence, it is critical to understand the metal flow in sand-molds, i.e., casting hydrodynamics to eliminate casting defects. While multiple numerical methods have been applied to simulate this phenomenon for decades, harsh foundry environments and expensive x-ray equipment have limited experimental approaches to accurately visualize metal flow in sand molds. In this paper, a novel approach to solve this challenge is proposed using Succinonitrile (SCN) as a more accurate metal analog in place of water. SCN has a long history in solidification research due to its BCC (Body-Centered-Cubic) crystal structure and dendrite-like solidification (melting temperature ~60 °C) like molten aluminum. However, this is the first reported study on applying SCN through novel casting hydrodynamics to accurately visualize melt flow for casting studies. This paper used numerical simulations and experiments using both water and SCN to identify the critical dimensionless numbers to perform accurate metal flow analog testing. Froude’s number and wall roughness were identified as critical variables. Experimental results show that SCN flow testing was more accurate in recreating the flow profile of molten aluminum, thus validating its utility as a metal analog for metal flow research. Findings from this study can be used in future metal flow analysis such as: runner, in-gate and integrated filling-feeding-solidification studies.
A Lightweight CNN for Wind Turbine Blade Defect Detection Based on Spectrograms
Authors: Zhu Yuefan , Liu Xiaoying
Published: January 2023

Since wind turbines are exposed to harsh working environments and variable weather conditions, wind turbine blade condition monitoring is critical to prevent unscheduled downtime and loss. Realizing that common convolutional neural networks are difficult to use in embedded devices, a lightweight convolutional neural network for wind turbine blades (WTBMobileNet) based on spectrograms is proposed, reducing computation and size with a high accuracy. Compared to baseline models, WTBMobileNet without data augmentation has an accuracy of 97.05%, a parameter of 0.315 million, and a computation of 0.423 giga floating point operations (GFLOPs), which is 9.4 times smaller and 2.7 times less computation than the best-performing model with only a 1.68% decrease in accuracy. Then, the impact of difference data augmentation is analyzed. The WTBMobileNet with augmentation has an accuracy of 98.1%, and the accuracy of each category is above 95%. Furthermore, the interpretability and transparency of WTBMobileNet are demonstrated through class activation mapping for reliable deployment. Finally, WTBMobileNet is explored in drones image classification and spectrogram object detection, whose accuracy and mAP@[0.5, 0.95] are 89.55% and 70.7%, respectively. This proves that WTBMobileNet not only has a good performance in spectrogram classification, but also has good application potential in drone image classification and spectrogram object detection.
Active Braking Strategy Considering VRU Motion States in Curved Road Conditions
Authors: Hong Liang , Li Liang , Ge Ruhai
Published: January 2023

Currently, the active braking system is primarily used to avoid collisions between vehicles and vulnerable road users (VRUs) traversing the road at a constant speed in straight road conditions. Research on the collision avoidance strategy has been conducted to enhance the protective effects of the active braking system for VRUs traversing the road in various motion states in curved road conditions. Firstly, the spatial position relationships between VRUs and turn-taking vehicles are established when VRUs traverse the road in various motion states from the outside or the inside of the curved road; a mathematical model is established to identify whether VRUs are in a dangerous condition. Secondly, the safe distance model is established to formulate the vehicle collision avoidance strategy. Thirdly, the active braking controller is designed based on the upper sliding mode control and the lower discrete PID control. Finally, the six collision test scenarios on the curved road are constructed by utilizing the Prescan and Matlab/Simulink software. The results show that the active braking system can avoid the collision between the vehicle and VRUs traversing the curved road in various motion states.
Transformer-Based Unsupervised Cross-Sensor Domain Adaptation for Electromechanical Actuator Fault Diagnosis
Authors: Chen Zihan , He Chao
Published: January 2023

There have been some successful attempts to develop data-driven fault diagnostic methods in recent years. A common assumption in most studies is that the data of the source and target domains are obtained from the same sensor. Nevertheless, because electromechanical actuators may have complex motion trajectories and mechanical structures, it may not always be possible to acquire the data from a particular sensor position. When the sensor locations of electromechanical actuators are changed, the fault diagnosis problem becomes further complicated because the feature space is significantly distorted. The literature on this subject is relatively underdeveloped despite its critical importance. This paper introduces a Transformer-based end-to-end cross-sensor domain fault diagnosis method for electromechanical actuators to overcome these obstacles. An enhanced Transformer model is developed to obtain domain-stable features at various sensor locations. A convolutional embedding method is also proposed to improve the model’s ability to integrate local contextual information. Further, the joint distribution discrepancy between two sensor domains is minimized by using Joint Maximum Mean Discrepancy. Finally, the proposed method is validated using an electromechanical actuator dataset. Twenty-four transfer tasks are designed to validate cross-sensor domain adaptation fault diagnosis problems, covering all combinations of three sensor locations under different operating conditions. According to the results, the proposed method significantly outperforms the comparative method in terms of varying sensor locations.
Time-Varying Granger Causality of COVID-19 News on Emerging Financial Markets: The Latin American Case
Authors: Coronado Semei , Martinez Jose N. , Gualajara Victor , Romero-Meza Rafael , Rojas Omar
Published: January 2023

This study uses daily COVID-19 news series to determine their impact on financial market volatility. This paper assesses whether U.S. financial markets react differently to COVID-19 news than emerging markets and if such markets are impacted differently by country-specific and global news. To detect the spillover effects from news on market volatility, a time-varying DCC-GARCH model was applied. The results suggest that the U.S. and emerging markets are affected differently by pandemic news, global series have a stronger impact on emerging markets than country-specific ones, and misleading information plays a significant role in financial market volatility, especially for the U.S.
Quasi-Metrics for Possibility Results: Intergenerational Preferences and Continuity
Authors: Estevan Asier , Maura Roberto , Valero Óscar
Published: January 2023

In this paper, we provide the counterparts of a few celebrated impossibility theorems for continuous social intergenerational preferences according to P. Diamond, L.G. Svensson and T. Sakai. In particular, we give a topology that must be refined for continuous preferences to satisfy anonymity and strong monotonicity. Furthermore, we suggest quasi-pseudo-metrics as an appropriate quantitative tool for reconciling topology and social intergenerational preferences. Thus, we develop a metric-type method which is able to guarantee the possibility counterparts of the aforesaid impossibility theorems and, in addition, it is able to give numerical quantifications of the improvement of welfare. Finally, a refinement of the previous method is presented in such a way that metrics are involved.
Three-Dimensional Force Decouping-Sensing Soft Sensor with Topological Elastomer
Authors: Zhu Dachang , Wu Longfei , He Yonglong
Published: January 2023

Sensing the deformation of soft sensor elastomer can realize the flexible operation of soft robot and enhance the perception of human-computer interaction. The structural configuration of elastomer and its elastic deformation force transfer path are crucial for decoupling sensing and studying the sensing performance of three-dimensional force soft sensor. In this article, we present a theoretical method for soft sensor with three-dimensional force decoupling-sensing. First, the constraint types of parallel manipulator with three translational motion characteristics are analyzed and used to set the constraint conditions for topology optimization. In addition, the differential kinematic modeling method is adopted to establish the differential kinematic equation of the three translations parallel manipulator, which is used as a pseudo-rigid body model for sensor information perception. Second, combining the kinematic Jacobi matrix with solid isotropic material with penalization the (SIMP), the topological model is built for designing of sensor elastomer. We optimized the composition of the material and evaluate the model’s sensing capabilities. The results validate a elastomer of soft sensor for unity between structural stiffness and perceived sensitivity.
Bilayer Lipid Membrane as Memcapacitance: Capacitance–Voltage Pinched Hysteresis and Negative Insertion Conductance
Authors: Smirnova Elena Yu. , Anosov Andrey A.
Published: January 2023

Inelastic (dissipative) effects of different natures in lipid bilayer membranes can lead to hysteresis phenomena. Early, it was shown that lipid bilayer membranes, under the action of a periodic sinusoidal voltage, demonstrate pinched-hysteresis loops in the experimental capacitance–voltage dependences and are almost the only example of the physical implementation of memcapacitance. Here, we propose an equivalent circuit and mathematical framework for analyzing the dynamic nonlinear current response of a lipid bilayer membrane as an externally controlled memcapacitance. Solving a nonlinear differential equation for the equivalent circuit of a membrane in the form of a parallel connection of a nonlinear viscoelastic capacitor and an active resistance using the small parameter method, we obtain explicit analytical dependences for the current response of the membrane and pinched-hysteresis loops. The explicit solutions and their comparison with experimental data allow us to identify the lumped equivalent circuit parameters that govern the memcapacitor behavior of the membrane and hence the magnitude of the hysteresis. We quantify the memcapacitance hysteresis in terms of negative work done by the control signal. An analysis of the formulas leads to the conclusion that the determining factor for the appearance of pinched hysteresis is the type of nonlinear dependence of the device capacitance on voltage.
A Phenomenological Model for Electrical Transport Characteristics of MSM Contacts Based on GNS
Authors: Rahmani Meisam , Ghafoorifard Hassan , Ahmadi Mohammad Taghi
Published: January 2023

Graphene nanoscroll, because of attractive electronic, mechanical, thermoelectric and optoelectronics properties, is a suitable candidate for transistor and sensor applications. In this research, the electrical transport characteristics of high-performance field effect transistors based on graphene nanoscroll are studied in the framework of analytical modeling. To this end, the characterization of the proposed device is investigated by applying the analytical models of carrier concentration, quantum capacitance, surface potential, threshold voltage, subthreshold slope and drain induced barrier lowering. The analytical modeling starts with deriving carrier concentration and surface potential is modeled by adopting the model of quantum capacitance. The effects of quantum capacitance, oxide thickness, channel length, doping concentration, temperature and voltage are also taken into account in the proposed analytical models. To investigate the performance of the device, the current-voltage characteristics are also determined with respect to the carrier density and its kinetic energy. According to the obtained results, the surface potential value of front gate is higher than that of back side. It is noteworthy that channel length affects the position of minimum surface potential. The surface potential increases by increasing the drain-source voltage. The minimum potential increases as the value of quantum capacitance increases. Additionally, the minimum potential is symmetric for the symmetric structure (Vfg = Vbg). In addition, the threshold voltage increases by increasing the carrier concentration, temperature and oxide thickness. It is observable that the subthreshold slope gets closer to the ideal value of 60 mV/dec as the channel length increases. As oxide thickness increases the subthreshold slope also increases. For thinner gate oxide, the gate capacitance is larger while the gate has better control over the channel. The analytical results demonstrate a rational agreement with existing data in terms of trends and values.
Static Hydrophobic Cuprous Oxide Surface Fabricated via One-Step Laser-Induced Oxidation of a Copper Substrate
Authors: Yu Xi , Tanaka Yoshiki , Kakiuchi Tomoki , Ishida Takafumi , Saitoh Koh , Itoigawa Fumihiro , Kuwahara Makoto , Ono Shingo
Published: January 2023

In this study, we developed a one-step method for fabricating hydrophobic surfaces on copper (Cu) substrates. Cuprous oxide (Cu2O) with low free energy was successfully formed after low-fluence laser direct irradiation. The formation of Cu2O enhanced the hydrophobicity of the Cu substrate surface, and the contact angle linearly increased with the proportion of Cu2O. The Cu2O fabricated by low-fluence laser treatment showed the same crystal plane orientation as the pristine Cu substrate, implying an epitaxial growth of Cu2O on a Cu substrate.
Passivity-Based Control for Output Voltage Regulation in a Fuel Cell/Boost Converter System
Authors: Beltrán Carlo A. , Diaz-Saldierna Luis H. , Langarica-Cordoba Diego , Martinez-Rodriguez Panfilo R.
Published: January 2023

In this paper, a passivity-based control (PBC) scheme for output voltage regulation in a fuel-cell/boost converter system is designed and validated through real-time numerical results. The proposed control scheme is designed as a current-mode control (CMC) scheme with an outer loop (voltage) for voltage regulation and an inner loop (current) for current reference tracking. The inner loop’s design considers the Euler–Lagrange (E-L) formulation to implement a standard PBC and the outer loop is implemented through a standard PI controller. Furthermore, an adaptive law based on immersion and invariance (I&I) theory is designed to enhance the closed-loop system behavior through asymptotic approximation of uncertain parameters such as load and inductor parasitic resistance. The closed-loop system is tested under two scenarios using real-time simulations, where precision and robustness are shown with respect to variations in the fuel cell voltage, load, and output voltage reference.
Influenza Treatment: Limitations of Antiviral Therapy and Advantages of Drug Combination Therapy
Authors: Batool Sania , Chokkakula Santosh , Song Min-Suk
Published: January 2023

Influenza infection is serious and debilitating for humans and animals. The influenza virus undergoes incessant mutation, segment recombination, and genome reassortment. As a result, new epidemics and pandemics are expected to emerge, making the elimination challenging of the disease. Antiviral therapy has been used for the treatment of influenza since the development of amantadine in the 1960s; however, its use is hampered by the emergence of novel strains and the development of drug resistance. Thus, combinational therapy with two or more antivirals or immunomodulators with different modes of action is the optimal strategy for the effective treatment of influenza infection. In this review, we describe current options for combination therapy, their performance, and constraints imposed by resistance, calling attention to the advantages of combination therapy against severe influenza infections. We also discuss the challenges of influenza therapy and the limitations of approved antiviral drugs.
Examining Different Analysis Protocols Targeting Hospital Sanitary Facility Microbiomes
Authors: Neidhöfer Claudio , Sib Esther , Benhsain Al-Harith , Mutschnik-Raab Christina , Schwabe Anna , Wollkopf Alexander , Wetzig Nina , Sieber Martin A. , Thiele Ralf , Döhla Manuel , Engelhart Steffen , Mutters Nico T. , Parčina Marijo
Published: January 2023

Indoor spaces exhibit microbial compositions that are distinctly dissimilar from one another and from outdoor spaces. Unique in this regard, and a topic that has only recently come into focus, is the microbiome of hospitals. While the benefits of knowing exactly which microorganisms propagate how and where in hospitals are undoubtedly beneficial for preventing hospital-acquired infections, there are, to date, no standardized procedures on how to best study the hospital microbiome. Our study aimed to investigate the microbiome of hospital sanitary facilities, outlining the extent to which hospital microbiome analyses differ according to sample-preparation protocol. For this purpose, fifty samples were collected from two separate hospitals—from three wards and one hospital laboratory—using two different storage media from which DNA was extracted using two different extraction kits and sequenced with two different primer pairs (V1–V2 and V3–V4). There were no observable differences between the sample-preservation media, small differences in detected taxa between the DNA extraction kits (mainly concerning Propionibacteriaceae), and large differences in detected taxa between the two primer pairs V1–V2 and V3–V4. This analysis also showed that microbial occurrences and compositions can vary greatly from toilets to sinks to showers and across wards and hospitals. In surgical wards, patient toilets appeared to be characterized by lower species richness and diversity than staff toilets. Which sampling sites are the best for which assessments should be analyzed in more depth. The fact that the sample processing methods we investigated (apart from the choice of primers) seem to have changed the results only slightly suggests that comparing hospital microbiome studies is a realistic option. The observed differences in species richness and diversity between patient and staff toilets should be further investigated, as these, if confirmed, could be a result of excreted antimicrobials.
Current Trends in Metal Biomining with a Focus on Genomics Aspects and Attention to Arsenopyrite Leaching—A Review
Authors: Abashina Tatiana , Vainshtein Mikhail
Published: January 2023

The presented review is based on scientific microbiological articles and patents in the field of biomining valuable metals. The main attention is paid to publications of the last two decades, which illustrate some shifts in objects of interest and modern trends both in general and applied microbiology. The review demonstrates that microbial bioleaching continues to develop actively, despite various problems in its industrial application. The previous classic trends in the microbial bioleaching persist and remain unchanged, including (i) the search for and selection of new effective species and strains and (ii) technical optimization of the bioleaching process. Moreover, new trends were formed during the last decades with an emphasis on the phylogeny of leaching microbiota and on genomes of the leaching microorganisms. This area of genomics provides new, interesting information and forms a basis for the subsequent construction of new leaching strains. For example, this review mentions some changed strains with increased resistance to toxic compounds. Additionally, the review considers some problems of bioleaching valuable metals from toxic arsenopyrite.
Omicron Sub-Lineage BA.5 and Recombinant XBB Evasion from Antibody Neutralisation in BNT162b2 Vaccine Recipients
Authors: Brandolini Martina , Gatti Giulia , Grumiro Laura , Zannoli Silvia , Arfilli Valentina , Cricca Monica , Dirani Giorgio , Denicolò Agnese , Marino Maria Michela , Manera Martina , Mancini Andrea , Taddei Francesca , Semprini Simona , Sambri Vittorio
Published: January 2023

The recent emergence of a number of new SARS-CoV-2 variants resulting from recombination between two distinct parental lineages or sub-lineages within the same lineage has sparked the debate regarding potential enhanced viral infectivity and immune escape. Among these, XBB, recombinant of BA.2.10 and BA.2.75, has caused major concern in some countries due to its rapid increase in prevalence. In this study, we tested XBB escape capacity from mRNA-vaccine-induced (BNT162b2) neutralising antibodies compared to B.1 ancestral lineage and another co-circulating variant (B.1.1.529 BA.5) by analysing sera collected 30 days after the second dose in 92 healthcare workers. Our data highlighted an enhanced and statistically significant immune escape ability of the XBB recombinant. Although these are preliminary results, this study highlights the importance of immune escape monitoring of new and forthcoming variants and of the reformulation of existing vaccines.
Isolation of Novel Bacterial Strains Pseudomonas extremaustralis CSW01 and Stutzerimonas stutzeri CSW02 from Sewage Sludge for Paracetamol Biodegradation
Authors: Vargas-Ordóñez Antonio , Aguilar-Romero Inés , Villaverde Jaime , Madrid Fernando , Morillo Esmeralda
Published: January 2023

Paracetamol is one of the most used pharmaceuticals worldwide, but due to its widespread use it is detected in various environmental matrices, such as surface and ground waters, sediments, soils or even plants, where it is introduced mainly from the discharge of wastewater and the use of sewage sludge as fertilizer in agriculture. Its accumulation in certain organisms can induce reproductive, neurotoxic or endocrine disorders, being therefore considered an emerging pollutant. This study reports on the isolation, from sewage sludge produced in wastewater treatment plants (WWTPs), of bacterial strains capable of degrading paracetamol. Up to 17 bacterial strains were isolated, but only two of them, identified as Pseudomonas stutzeri CSW02 and Pseudomonas extremaustralis CSW01, were able to degrade very high concentrations of paracetamol in solution as a sole carbon and energy source, and none of them had been previously described as paracetamol degraders. These bacteria showed the ability to degrade up to 500 mg L−1 of paracetamol in only 6 and 4 h, respectively, much quicker than any other paracetamol-degrader strain described in the literature. The two main paracetamol metabolites, 4-aminophenol and hydroquinone, which present high toxicity, were detected during the degradation process, although they disappeared very quickly for paracetamol concentrations up to 500 mg L−1. The IC50 of paracetamol for the growth of these two isolates was also calculated, indicating that P. extremaustralis CSW01 was more tolerant than S. stutzeri CSW02 to high concentrations of paracetamol and/or its metabolites in solution, and this is the reason for the much lower paracetamol degradation by S. stutzeri CSW02 at 2000–3000 mg L−1. These findings indicate that both bacteria are very promising candidates for their use in paracetamol bioremediation in water and sewage sludge.
Trace Element Composition of Molybdenite: Deposit Type Discrimination and Limitations
Authors: Tan Mao , Huang Xiaowen , Meng Yumiao , Tan Houmingrui
Published: January 2023

Molybdenite is a common sulfide hosting many trace elements. Trace elements in molybdenite from individual deposits have been widely used to constrain the source and conditions of ore-forming fluids. However, the relationship between the trace element composition of molybdenite and deposit types has not been well investigated from a large dataset. Here, simple statistics and partial least squares–discriminant analysis (PLS-DA) were used to determine whether different types of deposits can be distinguished by trace elements in molybdenite and what factors control the variations in trace element composition based on published laser ablation ICP–MS data. Molybdenite from porphyry deposits is separated from that from quartz veins, greisen Sn–W, granite vein Mo, and granodiorite Mo deposits. The former is characterized by relatively high Re, Cu, Ag, Se, Pb, Bi, and Te contents, whereas the latter has higher Ni, Co, Sn, Sb and W contents. Molybdenite from the quartz vein Au ± W deposits (Au-dominated), and porphyry Cu–Au–Mo (moderate Au) are separated from other deposits without gold due to positive correlations with Au, Sb, Te, Pb, and Bi for the former. Assemblages of Au–Sb–Te–Pb–Bi in molybdenite are thus useful to discriminate as to whether deposits contain gold and the degree of gold mineralization. Higher oxygen fugacity is responsible for the relative enrichment of W in molybdenite from greisen Sn–W deposits, whereas lower oxygen fugacity results in the relative enrichment of Re in molybdenite from porphyry Cu ± Mo ± Au and Mo ± Cu ± Au deposits. There are some limitations to using molybdenite as an indicator mineral because of the complex occurrences of elements in molybdenite, large compositional variations within a specific deposit type, and an imbalanced dataset. To develop molybdenite as an indicator mineral tool, further work should be carried out to overcome these limitations. This study provides an attempt to classify deposit types using molybdenite trace elements and has important implications for ore genesis research and mineral exploration.
Corona-Type Textures in Ultrabasic Complexes of the Serpentinite Belt, Kola Peninsula, Russia
Authors: Barkov Andrei Y. , Nikiforov Andrey A. , Martin Robert F. , Korolyuk Vladimir N.
Published: January 2023

For the first time, corona-type textures are described in ultrabasic rocks in three complexes of the Serpentinite Belt on the Kola Peninsula in the northeastern Fennoscandian Shield. Three variants of the corona texture formed at different stages during the crystallization of a komatiitic, Al-undepleted melt emplaced in a subvolcanic setting. The first type crystallized at an early stage (Mg# Ol = 87) in a fine-grained harzburgite of the Chapesvara-I sill, with the following order in the corona: Ol → Opx → Cpx → Pl → Amp (aluminous sodic-calcic). The second type displays the sequence Opx → Cpx → Amp → Pl → Qz, which is observed in the orthopyroxenite zone in the Lotmvara-I sill. The third type involves a symplectitic corona in a plagioclase-bearing orthopyroxenite in the Lyavaraka complex, in which the inferred order is: Cpx → Amp (aluminous hornblende) + symplectitic Qz, formed in direct contact with grains of Pl. The corona-type textures occur in fresh rocks and are not related to regional metamorphism. They likely formed as consequences of two important factors: (1) rapid cooling, leading to unsteady conditions of crystallization in a shallow setting; and (2) an intrinsic enrichment in H2O and other volatiles in the parental magma, giving rise to fluid-saturated environments at advanced stages of crystallization. This was followed by a deuteric deposition of Amp rims as a result of the accumulation of H2O and reaction of H2O-bearing fluid with early grains of pyroxene and late plagioclase. The likely existence of a close relationship is suggested by the drusites of the Belomorian complex, which are coeval. In addition, unusual occurrences of lamellar inclusions of phlogopite and Al2SiO5 are documented, hosted by interstitial grains of plagioclase in the orthopyroxenite zone of the Lotmvara-I sill. These are attributed to crystallization from late portions of remaining melt enriched in Al, K, Na, H2O, and Cl, which is indicated by the recorded occurrence of chlorapatite in this association. Thus, our findings indicate the presence and abundance of intrinsic volatiles, Cl, F, CO2, and especially magmatic H2O, which were important to lower the liquidus, decrease the density and viscosity of the highly magnesian melt of Al-undepleted komatiite, thus enabling its transport from the mantle to a shallow level in the crust.
Synthesis and Molecular Docking Study of Novel Pyrimidine Derivatives against COVID-19
Authors: Alamshany Zahra M. , Khattab Reham R. , Hassan Nasser A. , El-Sayed Ahmed A. , Tantawy Mohamed A. , Mostafa Ahmed , Hassan Allam A.
Published: January 2023

A novel series of pyrido[2,3-d]pyrimidines; pyrido[3,2-e][1,3,4]triazolo; and tetrazolo[1,5-c]pyrimidines were synthesized via different chemical transformations starting from pyrazolo[3,4-b]pyridin-6-yl)-N,N-dimethylcarbamimidic chloride 3b (prepared from the reaction of o-aminonitrile 1b and phosogen iminiumchloride). The structures of the newly synthesized compounds were elucidated based on spectroscopic data and elemental analyses. Designated compounds are subjected for molecular docking by using Auto Dock Vina software in order to evaluate the antiviral potency for the synthesized compounds against SARS-CoV-2 (2019-nCoV) main protease M pro. The antiviral activity against SARS-CoV-2 showed that tested compounds 7c, 7d, and 7e had the most promising antiviral activity with lower IC50 values compared to Lopinavir, “the commonly used protease inhibitor”. Both in silico and in vitro results are in agreement.
Novel Anti-Cancer Products Targeting AMPK: Natural Herbal Medicine against Breast Cancer
Authors: Peng Bo , Zhang Si-Yuan , Chan Ka Iong , Zhong Zhang-Feng , Wang Yi-Tao
Published: January 2023

Breast cancer is a common cancer in women worldwide. The existing clinical treatment strategies have been able to limit the progression of breast cancer and cancer metastasis, but abnormal metabolism, immunosuppression, and multidrug resistance involving multiple regulators remain the major challenges for the treatment of breast cancer. Adenosine 5′-monophosphate (AMP)-Activated Protein Kinase (AMPK) can regulate metabolic reprogramming and reverse the “Warburg effect” via multiple metabolic signaling pathways in breast cancer. Previous studies suggest that the activation of AMPK suppresses the growth and metastasis of breast cancer cells, as well as stimulating the responses of immune cells. However, some other reports claim that the development and poor prognosis of breast cancer are related to the overexpression and aberrant activation of AMPK. Thus, the role of AMPK in the progression of breast cancer is still controversial. In this review, we summarize the current understanding of AMPK, particularly the comprehensive bidirectional functions of AMPK in cancer progression; discuss the pharmacological activators of AMPK and some specific molecules, including the natural products (including berberine, curcumin, (−)-epigallocatechin-3-gallate, ginsenosides, and paclitaxel) that influence the efficacy of these activators in cancer therapy; and elaborate the role of AMPK as a potential therapeutic target for the treatment of breast cancer.