bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the Shear Modulus Based Equivalent Homogenization Methods of Multi-Layer BCC Lattice Sandwich
Authors: Zhang Wukun , Zhao Jian , Tan Yonghua , Gao Yushan , Wang Jun , Geng Xiaoliang
Published: February 2022

In this paper, the shear modulus based equivalent homogenization methods of multi-layer BCC (body-centered cubic) lattice sandwich structures have been studied using analytical, experimental, and finite element methods. In the analytical approach, the multiple strut-deformation patterns were introduced in the derivations of the shear modulus based on Euler–Bernoulli beam theory and Timoshenko beam theory according to different boundary conditions. The analytical shear modulus of three types of rectangle shaped sandwich BCC lattice structures was derived. Finite element models of the BCC lattice structures by ANSYS were conducted to estimate the analytical solutions. Butterfly style sandwich BCC lattice structures were printed by SLM technology using 304 stainless steel (06Cr19Ni10), and corresponding shear experiments using modified Arcan Rig experimental devices were conducted to validate the analytical and numerical calculations. Good agreements were observed among the analytical, numerical, and experimental results.
Freezing and Thawing Resistance of Fine Recycled Concrete Aggregate (FRCA) Mixtures Designed with Distinct Techniques
Authors: Trottier Cassandra , de Grazia Mayra T. , Macedo Hian F. , Sanchez Leandro F. M. , Andrade Gabriella P. de , de Souza Diego J. , Naboka Olga , Fathifazl Gholamreza , Nkinamubanzi Pierre-Claver , Demers André
Published: February 2022

The pressure to use sustainable materials and adopt practices reducing the carbon footprint of the construction industry has risen. Such materials include recycled concrete aggregates (RCA) made from waste concrete. However, concrete made with RCA often presents poor fresh and hardened properties along with a decrease in its durability performance, especially when using its fine fraction (i.e., FRCA). Most studies involving FRCA use direct replacement methods (DRM) to proportion concrete although other techniques are available such as the Equivalent Volume (EV) and Particle Packing Models (PPMs); yet their impact on the durability performance, especially its performance against freezing and thawing (F/T), remains unknown. This work, therefore, appraises the F/T resistance of FRCA mixtures proportioned through various mix proportioning techniques (i.e., DRM, EV and PPMs), produced with distinct crushing processes (i.e., crusher’s fines vs. finely ground). The results show that the mix design technique has a significant influence on the FRCA mixture’s F/T resistance where PPM-proportioned mixtures demonstrate the best overall performance, exceeding the specified requirements while DRM-proportioned mixtures failed F/T resistance requirements. Moreover, the crushing process plays an important role in the recycled mixtures’ cracking behavior under F/T cycles, where less processing leads to fewer cracks while remaining the most sustainable option overall.
Effect of Laser Speed and Hatch Spacing on the Corrosion Behavior of 316L Stainless Steel Produced by Selective Laser Melting
Authors: Collazo Antonio , Figueroa Raúl , Pérez Carmen , Nóvoa Xosé Ramón
Published: February 2022

In this work, the corrosion properties of 316L stainless steel (SS) obtained by selective laser melting (SLM) are analyzed. The electrochemical results of samples manufactured with an energy density between 40 and 140 J/mm3 are compared using different hatch distances and laser speeds. The analysis correlates the impact of the microstructure and processing defects of SLM 316L stainless steel on its behavior against corrosion. The optimal manufacturing conditions were selected considering the electrochemical results. Although the samples obtained with an energy density close to 90 J/mm3 show a high resistance to corrosion, their performance depends on the combination of selected parameters, obtaining the best results for an intermediate laser speed and a low hatch distance. These manufacturing conditions produce a higher breakdown potential, a faster repassivation of the steel and reduce the current density on electrochemical test.
Reinforcement of Frictional Vibration Noise Reduction Properties of a Polymer Material by PTFE Particles
Authors: Li Naner , Dong Conglin , Wu Yuhang
Published: February 2022

The insufficient lubrication of the contact interface between moving parts can easily induce severe friction vibration and noise under extreme working conditions, which will threaten the service life and reliability of polymer moving components, including water-lubricated stern tube polymer bearings. Thermoplastic polyurethane (TPU) modified by polytetrafluoroethylene (PTFE) particles was developed. The effects of PTFE on the wear and vibration behaviors of modified TPU sliding against the ZCuSn10Zn2 ring-plates were investigated. The coefficients of friction (COFs), wear mass losses, wear morphologies, frictional vibration, and noise were analyzed synthetically. The results showed that a suitable mass content of PTFE reduced the COFs and wear mass losses of the TPU composites by more than 50% and 40%, respectively, while presenting an excellent friction reduction. The lower COFs of modified TPU showed a small fluctuation amplitude and eliminated vibration waveforms at high vibrational frequencies, which was useful for reducing frictional vibration and noise. The knowledge gained in this study is useful for a better understanding of the wear behaviors of polymer composites, as well as for the design a new polymer material with good self-lubricating and frictional vibration and noise reduction properties.
Microtensile Bond Strength of Bioactive Pit and Fissure Sealants Bonded to Primary and Permanent Teeth
Authors: AlQahtani Abdulelah , Al-Dlaigan Yousef , Almahdy Ahmed
Published: February 2022

Background: Sealing occlusal pits and fissures is an effective preventive measure against dental caries. Pit and fissure sealants (PFS) should be strongly bonded to the teeth to prevent partial or complete loss of the sealant, which may limit its preventive effect. Objective: The objective of the study was to compare the microtensile bond strength (μTBS) of bioactive resin-based sealants (Bio-RBS) and resin-based sealants (RBS), with and without the use of a bonding agent, to the enamel of primary and permanent teeth. Methods: One hundred and twenty caries-free primary molar specimens and 120 permanent molar specimens were divided to eight groups (30 specimens per group), both primary and permanent teeth were sealed with a Bio-RBS BioCoatTM (Premier®, Plymouth Meeting, PA, USA) or with a RBS ClinproTM (3M ESPE, Saint Paul, MN, USA), with or without the use of a bonding agent (Prime & Bond NT; Dentsply, Inc., Charlotte, NC, USA). Half the specimens were aged with 5000 thermal cycles, and all specimens were tested for the μTBS and failure mode. Results: The mean μTBS of aged Bio-RBS was higher in permanent teeth than primary teeth, and the aging process reduced the μTBS of RBS more than that of Bio-RBS. Moreover, the addition of a bonding agent improved the μTBS of aged RBS in permanent teeth. Conclusion: We concluded that Bio-RBS exhibit superior μTBS than RBS when applied to permanent teeth.
Study of New Nitrogen-Fireable Copper-Nickel Thick Film Paste Formulation Compatible with Thick Printed Copper
Authors: Hlina Jiri , Reboun Jan , Simonovsky Marek , Syrovy Tomas , Janda Martin , Hamacek Ales
Published: February 2022

This paper is focused on a new copper-nickel thick film resistive paste which was designed and experimentally developed for the realization of low-ohmic power resistors. This copper-nickel paste has been designed for use in combination with thick printed copper conductors and in comparison with conventional ruthenium-based thick film resistor pastes allows firing in a nitrogen protective atmosphere. The copper-nickel paste was prepared from copper and nickel microparticles, glass binder particles and a combination of organic solvents optimized for its firing in a nitrogen atmosphere. This paper covers a detailed description of copper-nickel paste composition and its thermal properties verified by simultaneous thermal analysis, a description of the morphology of dried and fired copper-nickel films, as well as the electrical parameters of the final printed resistors. It has been proven by electron microscopy with element distribution analysis that copper and nickel microparticles diffused together during firing and created homogenous copper-nickel alloy film. This film shows a low temperature coefficient of resistance ±45 × 0−6 K−1 and low sheet resistance value 45 mΩ/square. It was verified that formulated copper-nickel paste is nitrogen-fireable and well-compatible with thick printed copper pastes. This combination allows the realization of power substrates with directly integrated low-ohmic resistors.
Production of Fungal Nanochitosan Using High-Pressure Water Jet System for Biomedical Applications
Authors: Ogura Kota , Brasselet Clément , Cabrera-Barjas Gustavo , Hamidi Masoud , Shavandi Amin , Dols-Lafargue Marguerite , Sawamura Naoki , Delattre Cédric
Published: February 2022

In this present work, fungal nanochitosans, with very interesting particle size distribution of 22 µm, were efficiently generated in high-yield production using a high-pressure water jet system (Star Burst System, Sugino, Japan) after 10 passes of mechanical treatment under high pressure. The specific characterization of fungal chitosan nanofibers suspensions in water revealed a high viscosity of 1450 mPa.s and an estimated transparency of 43.5% after 10 passes of fibrillation mechanical treatment. The mechanical characterization of fungal nanochitosan (NC) film are very interesting for medical applications with a Young’s modulus (E), a tensile strength (TS), and elongation at break (e%) estimated at 2950 MPa, 50.5 MPa, and 5.5%, respectively. Furthermore, we exhibited that the fungal nanochitosan (NC) film presented very good long-term antioxidant effect (reached 82.4% after 96 h of contact with DPPH radical solution) and very interesting antimicrobial activity when the nanochitosan (NC) fibers are mainly activated as NC-NH3+ form at the surface of the film with 45% reduction and 75% reduction observed for S. aureus (Gram-positive) and E. coli (Gram-negative), respectively, after 6 h of treatment. These promising antimicrobial and antioxidant activities indicated the high potential of valorization toward biomedical applications.
Orientation Dependent Hardening by <001> Rod-Shaped Misfitting Precipitates in Aluminium Alloys
Authors: Liu Jianbin , Muraishi Shinji
Published: February 2022

A coherent precipitate formed in a metallic alloy is of importance in its strengthening mechanism, owing to dislocation/precipitate interaction. Therefore, the present study investigated the effect of <001> rod-shaped precipitates on misfit hardening in aluminium alloys by means of parametric dislocation dynamics simulation based on Green’s function method. The simulation results revealed that the topological evolution of the dislocation microstructure is greatly influenced by local internal stress around the <001> rod precipitate. The strong orientation dependence of misfit hardening was observed for the gradients of the stress–strain curves and their maximum shear stresses, where the difference in the maximum stress values amounted to 30%. The strong and weak hardening behaviours associated with the internal stress of <001> rod precipitates were implemented in terms of the energy associated with the dislocation motion.
Design of a Hydrostatic Spindle and Its Simulation Analysis with the Application to a High Precision Internal Grinding Machine
Authors: Shang Youyun , Cheng Kai , Ding Hui , Chen Shijin
Published: February 2022

Hydrostatic thrust bearings are the core part of the hydrostatic spindle, which is widely used in high precision grinding machines. In this paper, the viscosity-temperature (v-t) characteristics of hydrostatic oil are systematically investigated, which is essential for improving the performance of the hydrostatic thrust bearing and the spindle working at high pressure and high rotational speed. Based on the computational fluid dynamics (CFD) simulation developed, the performance variation rules of thrust bearing surface are established while changing the oil supply pressure. It is found that the bearing capacity and temperature are obviously affected by varying viscosity-temperature characteristics, which have significant fluctuation phenomenon at the orifice. Furthermore, the turbulence intensity of the taper hole is found the least factor by analyzing four kinds of commonly used orifice type configurations. Finally, comparing the simulation and experimental results, the v-t model developed is proofed well matching with the experiment. The model can provide a basis for accurate design and analysis of hydrostatic thrust bearings and consequently the effective design and analysis of the hydrostatic spindle for high precision grinding machine.
Dynamic Analysis of an Enhanced Multi-Frequency Inertial Exciter for Industrial Vibrating Machines
Authors: Gursky Volodymyr , Krot Pavlo , Korendiy Vitaliy , Zimroz Radosław
Published: February 2022

Multi-frequency vibrators have advantages in bulk materials processing but their design is usually complicated. This article presents the synthesis of design parameters of a two-frequency inertial vibrator according to the specified power characteristics. Based on the developed mathematical model, the parameters of variable periodic force is derived for two angular velocities 157, 314 rad/s and their ratios 0.5 and 2. In the case of the 0.5 ratio, the instant angular velocity of the resulting force vector is 2.0–3.5 times greater than for ratio 2. A dynamical model of vibrating screen with the synthesized inertial drive is considered. It was found that at the ratio of angular velocities 0.5, the second harmonic of acceleration prevails at 50 Hz, while at the ratio of 2, the first harmonic has a greater amplitude at 25 Hz. For the first variant, the power does not depend on the initial angle between unbalances, and at the second variant, it can vary. The angle of rotation of unbalances affects the trajectory of the centre of mass and the phases of the harmonics but does not affect their amplitude. Due to such dynamical features, the two-motor inertial drive allows the vibrating machines to operate at a wider range of frequencies and amplitudes.
Developing and Implementing a Lean Performance Indicator: Overall Process Effectiveness to Measure the Effectiveness in an Operation Process
Authors: Ng Corrales Lisbeth del Carmen , Lambán María Pilar , Morella Paula , Royo Jesús , Sánchez Catalán Juan Carlos , Hernandez Korner Mario Enrique
Published: February 2022

The purpose of this paper is to build up and implement a framework of a lean performance indicator with collaborative participation. A new indicator derived from OEE is presented, overall process effectiveness (OPE), which measures the effectiveness of an operation process. The action research (AR) methodology was used; collaborative work was done between researchers and management team participation. The framework was developed with the researchers’ and practitioners’ experiences, and the data was collected and analyzed; some improvements were applied and finally, a critical reflection of the process was done. This new metric contributes to measuring the unloading process, identifying losses, and generating continuous improvement plans tailored to organizational needs, increasing their market competitiveness and reducing the non-value-add activities. The OEE framework is implemented in a new domain, opening a new line of research applied to logistic process performance. This framework contributes to recording and measuring the data of one unloading area and could be extrapolated to other domains for lean performance. It was possible to generate and validate knowledge applied in the field. This study makes collaborative participation providing an effectiveness indicator that helps the managerial team to make better decisions through AR methodology.
Explainable Machine Learning Reveals Capabilities, Redundancy, and Limitations of a Geospatial Air Quality Benchmark Dataset
Authors: Stadtler Scarlet , Betancourt Clara , Roscher Ribana
Published: February 2022

Air quality is relevant to society because it poses environmental risks to humans and nature. We use explainable machine learning in air quality research by analyzing model predictions in relation to the underlying training data. The data originate from worldwide ozone observations, paired with geospatial data. We use two different architectures: a neural network and a random forest trained on various geospatial data to predict multi-year averages of the air pollutant ozone. To understand how both models function, we explain how they represent the training data and derive their predictions. By focusing on inaccurate predictions and explaining why these predictions fail, we can (i) identify underrepresented samples, (ii) flag unexpected inaccurate predictions, and (iii) point to training samples irrelevant for predictions on the test set. Based on the underrepresented samples, we suggest where to build new measurement stations. We also show which training samples do not substantially contribute to the model performance. This study demonstrates the application of explainable machine learning beyond simply explaining the trained model.
Buckling Response of Functionally Graded Porous Plates Due to a Quasi-3D Refined Theory
Authors: Zenkour Ashraf M. , Aljadani Maryam H.
Published: February 2022

A quasi-3D refined theory is used to investigate the buckling response of functionally graded (FG) porous plates. The present theory takes into consideration the effect of thickness stretching. Three models of FG porous plates are presented: an isotropic FG porous plate, FG skins with a homogenous core, and an FG core with homogenous skins. The FG porous material properties vary along with the thickness of the FG layer based on modified polynomial law. By using the principle of total potential energy, the equilibrium equations are obtained. The buckling response is determined for simply supported FG porous plates. Analytical investigations are verified to present the accuracy of the current quasi-3D refined theory in predicting the buckling response of FG porous plates. The effect of thickness stretching and several parameters such as porosity coefficients, mechanical loadings, geometric parameters, gradient indexes, and layer thickness ratios are discussed. It is observed that the current theory shows more accurate results for the buckling response of FG plates compared with other shear deformation theories.
On a Fractional Stochastic Risk Model with a Random Initial Surplus and a Multi-Layer Strategy
Authors: Pirozzi Enrica
Published: February 2022

The paper deals with a fractional time-changed stochastic risk model, including stochastic premiums, dividends and also a stochastic initial surplus as a capital derived from a previous investment. The inverse of a ν-stable subordinator is used for the time-change. The submartingale property is assumed to guarantee the net-profit condition. The long-range dependence behavior is proven. The infinite-horizon ruin probability, a specialized version of the Gerber–Shiu function, is considered and investigated. In particular, we prove that the distribution function of the infinite-horizon ruin time satisfies an integral-differential equation. The case of the dividends paid according to a multi-layer dividend strategy is also considered.
Forecasting of Electrical Energy Consumption in Slovakia
Authors: Pavlicko Michal , Vojteková Mária , Blažeková Oľga
Published: February 2022

Prediction of electricity energy consumption plays a crucial role in the electric power industry. Accurate forecasting is essential for electricity supply policies. A characteristic feature of electrical energy is the need to ensure a constant balance between consumption and electricity production, whereas electricity cannot be stored in significant quantities, nor is it easy to transport. Electricity consumption generally has a stochastic behavior that makes it hard to predict. The main goal of this study is to propose the forecasting models to predict the maximum hourly electricity consumption per day that is more accurate than the official load prediction of the Slovak Distribution Company. Different models are proposed and compared. The first model group is based on the transverse set of Grey models and Nonlinear Grey Bernoulli models and the second approach is based on a multi-layer feed-forward back-propagation network. Moreover, a new potential hybrid model combining these different approaches is used to forecast the maximum hourly electricity consumption per day. Various performance metrics are adopted to evaluate the performance and effectiveness of models. All the proposed models achieved more accurate predictions than the official load prediction, while the hybrid model offered the best results according to performance metrics and supported the legitimacy of this research.
A New Approach to Rotational Weingarten Surfaces
Authors: Carretero Paula , Castro Ildefonso
Published: February 2022

Weingarten surfaces are those whose principal curvatures satisfy a functional relation, whose set of solutions is called the curvature diagram or the W-diagram of the surface. Making use of the notion of geometric linear momentum of a plane curve, we propose a new approach to the study of rotational Weingarten surfaces in Euclidean 3-space. Our contribution consists of reducing any type of Weingarten condition on a rotational surface to a first-order differential equation on the momentum of the generatrix curve. In this line, we provide two new classification results involving a cubic and an hyperbola in the W-diagram of the surface characterizing, respectively, the non-degenerated quadric surfaces of revolution and the elasticoids, defined as the rotational surfaces generated by the rotation of the Euler elastic curves around their directrix line. As another application of our approach, we deal with the problem of prescribing mean or Gauss curvature on rotational surfaces in terms of arbitrary continuous functions depending on distance from the surface to the axis of revolution. As a consequence, we provide simple new proofs of some classical results concerning rotational surfaces, such as Euler’s theorem about minimal ones, Delaunay’s theorem on constant mean curvature ones, and Darboux’s theorem about constant Gauss curvature ones.
Surgical Interventions in Cases of Esophageal Hiatal Hernias among Older Japanese Adults: A Systematic Review
Authors: Horinishi Yuta , Shimizu Kai , Sano Chiaki , Ohta Ryuichi
Published: February 2022

Background and Objectives: Given Japan’s superaging population, an increasing number of older adults in the country need surgical treatment for esophageal hiatal hernias. Accordingly, this systematic review examines surgical interventions for symptomatic esophageal hiatal hernias in older Japanese patients and explores treatment outcomes. Materials and Methods: Articles on single operations for hiatal hernias published after 1991 were found on Google Scholar and Ichushi using specific keywords. Subsequently, articles fulfilling the predetermined inclusion criteria were considered in the study. Results: The mean patient age was 81.4 years, and the male-to-female ratio was 1:11.5. The main reasons for surgery were vomiting, dyspnea, and chest tightness. In terms of hernia classification, type IV was the most common (48%). Surgical modalities were laparoscopy in 15 cases, and laparotomy in 10 cases. Mean postoperative course was 26.47 days until hospital discharge, and there were no cases of perioperative death. Conclusions: Findings showed that multiple factors were involved in older adults’ prognoses, and age was not the only biological factor. Therefore, aggressive surgical intervention should be considered for symptomatic older patients, even in the absence of surgery indicators.
Effect of Self-Made TiO2 Nanoparticle Size on the Performance of the PVDF Composite Membrane in MBR for Landfill Leachate Treatment
Authors: Wang Huiya , Ding Keqiang
Published: February 2022

The pollutant composition of landfill leachate is complex, and pollutant concentrations change greatly. Moreover, landfill leachates can easily penetrate into the soil and eventually pollute the ground water, which can cause environmental pollution and threaten human health. At present, landfill leachate treatment technology is still not mature. In this paper, the A/O-MBR (Anoxic–Aerobic Membrane Bioreactor) process is proposed to treat landfill leachate. To increase the hydrophilicity of the membranes and reduce the pollution of the membranes, the self-made TiO2 nanoparticles were used to modify the ultrafiltration membranes (PVDF-2). Meanwhile, PVDF-2 composite membranes showed the best separation performance. The optimum operating parameters were determined by changing the concentration of the pollutants in the reactor and selecting the dissolved oxygen, pH, and hydraulic residence time. The results show that the optimum operating conditions of MBR are mixed liquor suspended solids (MLSS) = 3200 mg/L, DO = 1.5–2.5 mg/L in a nitrifying tank, DO = 0–0.5 mg/L in a denitrifying tank, pH = 7–8, and a hydraulic retention time (HRT) = 5 h. To reach the “Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants” (GB18918-2002), the effluent of the MBR system further enters into the RO system. This work presents an environmentally friendly synthesis of TiO2 nanoparticles and added into PVDF. The addition of self-made TiO2 in PVDF membrane has improved the antifouling performance significantly, which has the potential for the treatment of landfill leachate.
Discrimination between the Two Closely Related Species of the Operational Group B. amyloliquefaciens Based on Whole-Cell Fatty Acid Profiling
Authors: Huynh Thu , Vörös Mónika , Kedves Orsolya , Turbat Adiyadolgor , Sipos György , Leitgeb Balázs , Kredics László , Vágvölgyi Csaba , Szekeres András
Published: February 2022

(1) Background: Bacillus velezensis and Bacillus amyloliquefaciens are closely related members of the “operational group B. amyloliquefaciens”, a taxonomical unit above species level within the ”Bacillus subtilis species complex”. They have similar morphological, physiological, biochemical, phenotypic, and phylogenetic characteristics. Thus, separating these two taxa from each another has proven to be difficult to implement and could not be pushed easily into the line of routine analyses. (2) Methods: The aim of this study was to determine whether whole FAME profiling could be used to distinguish between these two species, using both type strains and environmental isolates. Initially, the classification was determined by partial sequences of the gyrA and rpoB genes and the classified isolates and type strains were considered as samples to develop the identification method, based on FAME profiles. (3) Results: The dissimilarities in 16:0, 17:0 iso, and 17:0 FA components have drawn a distinction between the two species and minor differences in FA 14:0, 15:0 iso, and 16:0 iso were also visible. The statistical analysis of the FA profiles confirmed that the two taxa can be distinguished into two separate groups, where the isolates are identified without misreading. (4) Conclusions: Our study proposes that the developed easy and fast-automated identification tool based on cellular FA profiles can be routinely applied to distinguish B. velezensis and B. amyloliquefaciens.
Probabilistic Analysis of a French Legionellosis Outbreak Shows Potential Role of Wastewater Basin
Authors: Wallet France , Fontenay Leila , Cabanes Pierre-André
Published: February 2022

Based on the data from a French outbreak of legionellosis, a probabilistic approach was developed to analyze and assess the potential role of several suspected sources of contamination. Potential dates of exposure of all cases were determined using back-calculation, using two probability distribution functions to model incubation period. A probabilistic analysis and risk assessment were then used to determine the most probable sources of contamination for each wave of the outbreak. The risk assessment was based on parameters representing emission and dispersion of Legionella: level and duration of emission; aerosol dispersion capacity; and probability of potential exposure for each patient. Four types of facilities containing the Legionella epidemic strain were analyzed: cooling towers, aerated wastewater basins, high pressure water cleaners, and car wash stations. The results highlighted the potential role of an aerated wastewater basin in the outbreak in addition to cooling towers. The role of high-pressure water cleaners and car wash stations appeared to be non-significant. This study also reveals the lack of knowledge on facility parameters that can be useful for microbial risk assessments. This type of probabilistic analysis can be used to quantitatively assess the risk for various facilities in order to manage a legionellosis outbreak.
Pseudomonas bijieensis Strain XL17 within the P. corrugata Subgroup Producing 2,4-Diacetylphloroglucinol and Lipopeptides Controls Bacterial Canker and Gray Mold Pathogens of Kiwifruit
Authors: Ali Md. Arshad , Luo Jinyan , Ahmed Temoor , Zhang Jiannan , Xie Ting , Dai Dejiang , Jiang Jingyong , Zhu Jie , Hassan Sabry , Alorabi Jamal A. , Li Bin , An Qianli
Published: February 2022

Kiwifruit worldwide suffers from the devastating diseases of bacterial canker caused by Pseudomonas syringae pv. actinidiae (Psa) and gray mold caused by Botrytis cinerea. Here, an endophytic bacterium XL17 isolated from a rape crown gall was screened out for its potent antagonistic activities against Psa and B. cinerea. Strain XL17 and its cell-free culture filtrate (CF) inhibited the growth of Psa and B. cinerea, Psa-associated leaf necrosis, and B. cinerea-associated kiwifruit necrosis. Electron microscopy showed that XL17 CF could damage the cell structures of Psa and B. cinerea. Genome-based taxonomy revealed that strain XL17 belongs to Pseudomonas bijieensis within the P. corrugata subgroup of the P. fluorescens species complex. Among the P. corrugata subgroup containing 31 genomospecies, the presence of the phl operon responsible for the biosynthesis of the phenolic polyketide 2,4-diacetylphloroglucinol (DAPG) and the absence of the lipopeptide/quorum sensing island can serve as the genetic marker for the determination of a plant-protection life style. HPLC detected DAPG in extracts from XL17 CF. MALDI-TOF-MS analysis revealed that strain XL17 produced cyclic lipopeptides of the viscosin family and orfamide family. Together, phenotypic, genomic, and metabolic analyses identified that P. bijieensis XL17 producing DAPG and cyclic lipopeptides can be used to control bacterial canker and gray mold pathogens of kiwifruit.
Expression of Scytonemin Biosynthesis Genes under Alternative Stress Conditions in the Cyanobacterium Nostoc punctiforme
Authors: Bennett Janine , Soule Tanya
Published: February 2022

The indole-alkaloid scytonemin is a sunscreen pigment that is widely produced among cyanobacteria as an ultraviolet radiation (UVR) survival strategy. Scytonemin biosynthesis is encoded by two gene clusters that are known to be induced by long-wavelength radiation (UVA). Previous studies have characterized the transcriptome of cyanobacteria in response to a wide range of conditions, but the effect on the expression of scytonemin biosynthesis genes has not been specifically targeted. Therefore, the aim of this study is to determine the variable response of scytonemin biosynthesis genes to a variety of environmental conditions. Cells were acclimated to white light before supplementation with UVA, UVB, high light, or osmotic stress for 48 h. The presence of scytonemin was determined by absorbance spectroscopy and gene expression of representative scytonemin biosynthesis genes was measured using quantitative PCR. Scytonemin genes were up-regulated in UVA, UVB, and high light, although the scytonemin pigment was not detected under high light. There was no scytonemin or upregulation of these genes under osmotic stress. The lack of pigment production under high light, despite increased gene expression, suggests a time-dependent delay for pigment production or additional mechanisms or genes that may be involved in scytonemin production beyond those currently known.
A High-Fidelity Modelling Method for Mine Haul Truck Dumping Process
Authors: Young Aaron , Rogers William Pratt
Published: February 2022

Dumping is one of the main unit operations of mining. Notwithstanding a long history of using large rear dump trucks in mining, little knowledge exists on the cascading behavior of the run-of-mine material during and after dumping. In order to better investigate this behavior, a method for generating high fidelity models (HFMs) of dump profiles was devised and investigated. This method involved using unmanned aerial vehicles with mounted cameras to generate photogrammetric models of dumps. Twenty-eight dump profiles were created from twenty-three drone flights. Their characteristics were presented and summarized. Four types of dump profiles were observed to exist. Factors that influence the determination of these profiles include the location of the truck relative to the dump crest, the movement of the underlying dump material during the dumping process and the differences in the dump profile prior to dumping. The HFMs created in this study could possibly be used for calibrating computer simulations of dumps to better match reality.
Glucose/Ribitol Dehydrogenase and 16.9 kDa Class I Heat Shock Protein 1 as Novel Wheat Allergens in Baker’s Respiratory Allergy
Authors: Olivieri Mario , Spiteri Gianluca , Brandi Jessica , Cecconi Daniela , Fusi Marina , Zanoni Giovanna , Rizzi Corrado
Published: February 2022

Wheat allergens are responsible for symptoms in 60–70% of bakers with work-related allergy, and knowledge, at the molecular level, of this disorder is progressively accumulating. The aim of the present study is to investigate the panel of wheat IgE positivity in allergic Italian bakers, evaluating a possible contribution of novel wheat allergens included in the water/salt soluble fraction. The water/salt-soluble wheat flour proteins from the Italian wheat cultivar Bolero were separated by using 1-DE and 2-DE gel electrophoresis. IgE-binding proteins were detected using the pooled sera of 26 wheat allergic bakers by immunoblotting and directly recognized in Coomassie stained gel. After a preparative electrophoretic step, two enriched fractions were furtherly separated in 2-DE allowing for detection, by Coomassie, of three different proteins in the range of 21–27 kDa that were recognized by the pooled baker’s IgE. Recovered spots were analyzed by nanoHPLC Chip tandem mass spectrometry (MS/MS). The immunodetected spots in 2D were subjected to mass spectrometry (MS) analysis identifying two new allergenic proteins: a glucose/ribitol dehydrogenase and a 16.9 kDa class I heat shock protein 1. Mass spectrometer testing of flour proteins of the wheat cultivars utilized by allergic bakers improves the identification of until now unknown occupational wheat allergens.
Computational Simulations Highlight the IL2Rα Binding Potential of Polyphenol Stilbenes from Fenugreek
Authors: Kulkarni Apoorva M. , Parate Shraddha , Lee Gihwan , Kim Yongseong , Jung Tae Sung , Lee Keun Woo , Ha Min Woo
Published: February 2022

Widely used in global households, fenugreek is well known for its culinary and medicinal uses. The various reported medicinal properties of fenugreek are by virtue of the different natural phytochemicals present in it. Regarded as a promising target, interleukin 2 receptor subunit alpha (IL2Rα) has been shown to influence immune responses. In the present research, using in silico techniques, we have demonstrated the potential IL2Rα binding properties of three polyphenol stilbenes (desoxyrhaponticin, rhaponticin, rhapontigenin) from fenugreek. As the first step, molecular docking was performed to assess the binding potential of the fenugreek phytochemicals with IL2Rα. All three phytochemicals demonstrated interactions with active site residues. To confirm the reliability of our molecular docking results, 100 ns molecular dynamics simulations studies were undertaken. As discerned by the RMSD and RMSF analyses, IL2Rα in complex with the desoxyrhaponticin, rhaponticin, and rhapontigenin indicated stability. The RMSD analysis of the phytochemicals alone also demonstrated no significant structural changes. Based on the stable molecular interactions and comparatively slightly better MM/PBSA binding free energy, rhaponticin seems promising. Additionally, ADMET analysis performed for the stilbenes indicated that all of them obey the ADMET rules. Our computational study thus supports further in vitro IL2Rα binding studies on these stilbenes, especially rhaponticin.
Spectrophotometric Determination of Molybdenum(VI) as a Ternary Complex with 4-Nitrocatechol and Benzalkonium Chloride
Authors: Divarova Vidka V. , Saravanska Antoaneta , Toncheva Galya , Milcheva Nikolina , Delchev Vassil B. , Gavazov Kiril
Published: February 2022

A new liquid—liquid extraction system for molybdenum(VI) was studied. It contains 4-nitrocatechol (4NC) as a complexing chromogenic reagent and benzalkonium chloride (BZC) as a source of heavy cations (BZ+), which are prone to form chloroform-extractable ion-association complexes. The optimum conditions for the determination of trace molybdenum(VI) were found: concentrations of 4NC and BZC (7.5 × 10−4 mol dm−3 and 1.9 × 10−4 mol dm−3, respectively), acidity (3.75 × 10−2 mol dm−3 H2SO4), extraction time (3 min), and wavelength (439 nm). The molar absorptivity, limit of detection, and linear working range were 5.5 × 104 dm3 mol−1 cm−1, 5.6 ng cm−3, and 18.6–3100 μg cm−3, respectively. The effect of foreign ions was examined, and the developed procedure was applied to the analysis of synthetic mixtures and real samples (potable waters and steels). The composition of the extracted complex was 1:1:2 (Mo:4NC:BZ). Three possible structures of its anionic part [MoVI(4NC)O2(OH)2]2− were discussed based on optimizations at the B3LYP/3-21G level of theory, and simulated UV/Vis absorption spectra were obtained with the TD Hamiltonian.
Experimental Determination and Computational Prediction of Dehydroabietic Acid Solubility in (−)-α-Pinene + (−)-β-Caryophyllene + P-Cymene System
Authors: Qin Yanmin , Chen Xiaopeng , Wang Linlin , Wei Xiaojie , Nong Weijian , Wei Xuejuan , Liang Jiezhen
Published: February 2022

The solubility of dehydroabietic acid in (−)-α-pinene, p-cymene, (−)-β-caryophyllene, (−)-α-pinene + p-cymene, (−)-β-caryophyllene + p-cymene and (−)-α-pinene + (−)-β-caryophyllene were determined using the laser monitoring method at atmospheric pressure. The solubility of dehydroabietic acid was positively correlated with temperature from 295.15 to 339.46 K. (−)-α-pinene, p-cymene, and (−)-β-caryophyllene were found to be suitable for the solubilization of dehydroabietic acid. In addition, the non-random two liquid (NRTL), universal quasi-chemical (UNIQUAC), modified Apelblat, modified Wilson, modified Wilson–van’t Hoff, and λh models were applied to correlate the determined solubility data. The modified Apelblat model gave the minor deviation for dehydroabietic acid in monosolvents, while the λh equation showed the best result in the binary solvents. A comparative analysis of compatibility between solutes and solvents was carried out using Hansen solubility parameters. The thermodynamic functions of ΔsolH0, ΔsolS0, ΔsolG0 were calculated according to the van’t Hoff equation, indicating that the dissolution was an entropy-driven heat absorption process. The Conductor-like Screening Model for Real Solvents (COSMO-RS) combined with an experimental value was applied to predict the reasonable solubility data of dehydroabietic acid in the selected solvents systems. The interaction energy of the dehydroabietic acid with the solvent was analyzed by COSMO-RS.
Simultaneous Analysis for Quality Control of Traditional Herbal Medicine, Gungha-Tang, Using Liquid Chromatography–Tandem Mass Spectrometry
Authors: Seo Chang-Seob , Shin Hyeun-Kyoo
Published: February 2022

Gungha-tang (GHT), a traditional herbal medicine, consists of nine medicinal herbs (Cnidii Rhizoma, Pinelliae Tuber, Poria Sclerotium, Citri Unshius Pericarpium, Citri Unshius Pericarpium Immaturus, Aurantii Fructus Immaturus, Atracylodis Rhizoma Alba, Glycyrrhizae Radix et Rhizoma, and Zingiberis Rhizoma Recens). It has been used for various diseases caused by phlegm. This study aimed to develop and verify the simultaneous liquid chromatography–tandem mass spectrometry (LC–MS/MS) analysis method, using nine marker components (liquiritin apioside, neoeriocitrin, narirutin, naringin, hesperidin, neohesperidin, liquiritigenin, glycyrrhizin, and 6-shogaol) for quality control of GHT. LC–MS/MS analysis was conducted using a Waters TQ-XS system. All marker analytes were separated on a Waters Acquity UPLC BEH C18 column (2.1 × 100 mm, 1.7 μm) using gradient elution with a distilled water solution (containing 5 mM ammonium formate and 0.1% [v/v] formic acid)–acetonitrile mobile phase. LC–MS/MS multiple reaction monitoring (MRM) analysis was carried out in negative and positive ion modes of an electrospray ionization source. The developed LC–MS/MS MRM method was validated by examining the linearity, limits of detection and quantification, recovery, and precision. LOD and LOQ values of nine markers were calculated as 0.02–8.33 ng/mL and 0.05–25.00 ng/mL. The recovery was determined to be 89.00–118.08% and precision was assessed with a coefficient of variation value of 1.74–8.64%. In the established LC–MS/MS MRM method, all markers in GHT samples were detected at 0.003–16.157 mg/g. Information gathered during the development and verification of the LC–MS/MS method will be useful for the quality assessment of GHT and other herbal medicines.
LC–MS3 Strategy for Quantification of Carbamazepine in Human Plasma and Its Application in Therapeutic Drug Monitoring
Authors: Ma Dongxiao , Ji Zhengchao , Cao Haiwei , Huang Jing , Zeng Lei , Yin Lei
Published: February 2022

This study developed a detection method based on the strategy of HPLC/MS3 and verified its suitability by quantifying carbamazepine in human plasma. The high-performance liquid chromatography–tandem mass spectrometry (HPLC/MS3) system was performed using a Shimadzu UFLC XR liquid chromatography and a SCIEX QTRAP® 5500 linear ion trap triple quadrupole mass spectrometer. The specific operation was as follows: the sample protein was firstly precipitated using methanol, then carbamazepine and carbamazepine-D2N15 were separated on an ACQUITY UPLC HSS T3 column using the gradient elution with solvent A (0.1% formic acid) and solvent B (0.1% formic acid in acetonitrile) at a flow rate of 0.25 mL/min. Each sample was run for 7 min. This method was validated for various parameters including accuracy, precision, selectivity, linearity, LLOQ, etc. Only 5 μL of sample plasma could obtain the result of LLOD 0.5 µg/mL. The intra-day and inter-day precision was <8.23%, and accuracy was between −1.74% and 2.92%. This method was successfully used for monitoring the blood concentration of epilepsy patients after carbamazepine treatment.
Organic Synthesis via Transition Metal-Catalysis
Authors: Gabriele Bartolo
Published: February 2022

In recent years, the development of transition-metal-catalyzed reactions has acquired an increasing importance [...]
Performance of Thyme Oil@Na-Montmorillonite and Thyme Oil@Organo-Modified Montmorillonite Nanostructures on the Development of Melt-Extruded Poly-L-lactic Acid Antioxidant Active Packaging Films
Authors: Giannakas Aris E. , Salmas Constantinos E. , Leontiou Areti , Moschovas Dimitrios , Baikousi Maria , Kollia Eleni , Tsigkou Vasiliki , Karakassides Anastasios , Avgeropoulos Apostolos , Proestos Charalampos
Published: February 2022

Today, the use of natural biodegradable materials in the production processes is more and more adopted by industry to achieve cyclic economy targets and to improve environmental and human health indexes. Active packaging is the latest trend for food preservation. In this work, nanostructures were prepared by incorporation of thyme oil with natural natrium-montmorillonite and organo-montmorillonite with two different techniques, direct impregnation and the green evaporation–adsorption process. Such nanostructures were mixed with poly-L-lactic-acid for the first time via an extrusion molding process to develop a new packaging film. Comparisons of morphological, mechanical, and other basic properties for food packaging were carried out via XRD, FTIR, TG, SEM/EDS, oxygen and water vapor permeation, and antimicrobial and antioxidant activity for the first time. Results showed that poly-L-lactic-acid could be modified with clays and essential oils to produce improved active packaging films. The final product exhibits food odor prevention characteristics and shelf-life extension capabilities, and it could be used for active packaging. The films based on OrgMt clay seems to be more promising, while the thyme oil addition improves their behavior as active packaging. The PLLA/3%TO@OrgMt and PLLA/5%TO@OrgMt films were qualified between the tested samples as the most promising materials for this purpose.
Effects of Green Apple (Golden Delicious) and Its Three Major Flavonols Consumption on Obesity, Lipids, and Oxidative Stress in Obese Rats
Authors: Selek Aksoy Ilknur , Otles Semih
Published: February 2022

Obesity is becoming increasingly common all over the world and global strategies are accordingly being developed to prevent it. In order to support the strategies, the effects of green apple (Golden Delicious) and the consumption of its three major flavonols (quercetin-3-glucoside, quercetin-3-D-galactoside, and quercetin-3-rhamnoside) on body weight; the weight of liver, kidney, and spleen; some lipid parameters in serum; and total lipid ratios of liver and kidney and oxidative stress parameters of obese rats were studied. This study was conducted on two experimental groups: one of which was given an apple, and the other was given flavonols, in addition to their high-energy diet; along with a sham and a control rat group, for 4 weeks. According to results, there was no difference in body and organ weights between groups. The liver and kidney weights increased in obese rats, but there was no difference between the total lipid ratios in these organs. The addition of green apple and selected flavonols to the high-energy diet of rats was not sufficient to prevent the increase in body and organ weights, but it supported the reduction in some lipid fractions and in oxidative stress parameters of obese rats. Moreover, this study supported the argument that obesity causes most of the lipid fractions increase in serum and induces oxidative stress.