bluuebunny/crossref_metadata_2025 huggingface dataset:
A Study of IFN-α-Induced Chemokines CCL2, CXCL10 and CCL19 in Patients with Systemic Lupus Erythematosu
Authors: Geneva-Popova Mariela Gencheva , Popova-Belova Stanislava Dimitrova , Gardzheva Petya Nikolova , Kraev Krasimir Iliev
Published: February 2022

The role of IFN-α-induced chemokines CCL2, CXCL10 and CCL19 in different forms of SLE has not been studied in Bulgaria, with worldwide sources attributing varying degrees of importance. The aim of this study was to investigate the correlation between IFN-induced chemokines CCL2, CXCL10 and CCL19 and disease activity in patients with SLE over 24 months. Materials and methods: This study used data from 70 patients with SLE (age range 24–62 years) and a control group of 30 healthy volunteers matched for age and gender. Levels of chemokines CCL2, CXCL10 and CCL19 in lupus patients’ serum were measured by ELISA. The study examined clinical and clinical laboratory indicators, as well as measures of disease activity developed for lupus patients (SLEDAI and SLICC). Statistical program SPSS, Version 26 were used for statistical data processing with p < 0.05. At 24 months of follow-up, 12 patients were with deterioration, and they had an IFN-a of 363.76 ± 9.23 versus 116.1 ± 22.1 pg/mL of those who did not worsen, CCL2 278.3 ± 5.12 versus 89.4 ± 12.8, CXCL10 234.2 ± 6.13 versus 115.23 ± 5.9 p CCL19 776.25 ± 5.1 vs. 651.34 ± 9.0 during the first visit. Results: The mean values of CCL2, CXCL10 and CCL19 were higher in patients with SLE compared to healthy controls (p = 0.01). A strong significant association (p = 0.01) was found between the concentration of CCL2, CXCL10 and CCL19 and with patients’ age, disease duration, SLEDAI and SLICC. Conclusion: CCL2, CXCL10 and CCL19 serum levels were found to correlate with patients’ age and disease duration. The level of IFN-induced chemokines CCL2, CXCL10 and CCL19 has a prognostic value in terms of SLE disease activity and degree of organ damage.
“Superwobbling” and tRNA-34 Wobble and tRNA-37 Anticodon Loop Modifications in Evolution and Devolution of the Genetic Code
Authors: Lei Lei , Burton Zachary Frome
Published: February 2022

The genetic code evolved around the reading of the tRNA anticodon on the primitive ribosome, and tRNA-34 wobble and tRNA-37 modifications coevolved with the code. We posit that EF-Tu, the closing mechanism of the 30S ribosomal subunit, methylation of wobble U34 at the 5-carbon and suppression of wobbling at the tRNA-36 position were partly redundant and overlapping functions that coevolved to establish the code. The genetic code devolved in evolution of mitochondria to reduce the size of the tRNAome (all of the tRNAs of an organism or organelle). “Superwobbling” or four-way wobbling describes a major mechanism for shrinking the mitochondrial tRNAome. In superwobbling, unmodified wobble tRNA-U34 can recognize all four codon wobble bases (A, G, C and U), allowing a single unmodified tRNA-U34 to read a 4-codon box. During code evolution, to suppress superwobbling in 2-codon sectors, U34 modification by methylation at the 5-carbon position appears essential. As expected, at the base of code evolution, tRNA-37 modifications mostly related to the identity of the adjacent tRNA-36 base. TRNA-37 modifications help maintain the translation frame during elongation.
4,7-Bis(5-(9-hexyl-9H-carbazol-3-yl)thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-d]pyridazine
Authors: Chmovzh Timofey , Korshunov Vladislav , Taydakov Ilya , Rakitin Oleg
Published: February 2022

Donor molecules of the D-π-A-π-D type structure are often used for applications in organic photovoltaics. In this communication, bromination of 4,7-di(thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-d]pyridazine followed by Suzuki cross-coupling with carbazoleboronic acid gave 4,7-bis( 5-(9-hexyl-9H-carbazol-3-yl)thiophen-2-yl)-[1,2,5]thiadiazolo[3,4-d]pyridazine. The structure of the newly synthesized compounds was established by high resolution mass-spectrometry, 1H, 13C NMR, IR, and UV spectroscopy and mass-spectrometry. A study of the luminescent properties of the dye showed that it exhibits fluorescence in the near infrared region of the spectrum, which makes it a promising compound for use as an active emitting layer in NIR OLED as well as for other possible applications as an IR luminophore.
Bracket Bonding to All-Ceramic Materials with Universal Adhesives
Authors: Goracci Cecilia , Di Bello Giuseppe , Franchi Lorenzo , Louca Chris , Juloski Jelena , Juloski Jovana , Vichi Alessandro
Published: February 2022

The need for bracket bonding to ceramic restorations is increasing. The aim of this study was to evaluate the effect of universal adhesives on bracket adhesion to polished or glazed lithium disilicate (LDS) and monolithic zirconia (MZ) surfaces. One hundred and twenty brackets (N = 10) were bonded to either polished or glazed LDS (e.max CAD B32, Ivoclar Vivadent, Schaan, Liechtenstein) and MZ (In-Ceram® YZ, VITA, Bad Sackingen, Germany) blocks using three different adhesives combined with Transbond™ XT Paste (3M Unitek, Monrovia, CA, USA). Tested universal adhesives were Scotchbond™ Universal Adhesive (SU, 3M St. Paul, MN, USA) and Assure Plus (AP, Reliance, Itasca, IL, USA). Transbond™ XT Primer (XTP, 3M Unitek, Monrovia, CA, USA) served as a control adhesive. Bracket bond strength was measured in shear mode (SBS). Failure type was determined by the Modified Adhesive Remnant Index (ARI). Data were statistically analyzed. On polished LDS, SU yielded bracket SBS significantly superior to those of AP and XTP. On polished MZ, the use of SU and AP significantly enhanced bracket retention as compared with XTP. Low SBS values, below the threshold of clinical acceptability, were reached by all tested adhesives on glazed LDS and MZ specimens. SBS measurements corresponded with failure type observations. Universal adhesives SU and AP could be considered for use on polished LDS and MZ surfaces.
A Ternary Seismic Metamaterial for Low Frequency Vibration Attenuation
Authors: Chen Chen , Lei Jincheng , Liu Zishun
Published: February 2022

Structural vibration induced by low frequency elastic waves presents a great threat to infrastructure such as buildings, bridges, and nuclear structures. In order to reduce the damage of low frequency structural vibration, researchers proposed the structure of seismic metamaterial, which can be used to block the propagation of low frequency elastic wave by adjusting the frequency range of elastic wave propagation. In this study, based on the concept of phononic crystal, a ternary seismic metamaterial is proposed to attenuate low frequency vibration by generating band gaps. The proposed metamaterial structure is periodically arranged by cube units, which consist of rubber coating, steel scatter, and soft matrix (like soil). The finite element analysis shows that the proposed metamaterial structure has a low frequency band gap with 8.5 Hz bandwidth in the range of 0–20 Hz, which demonstrates that the metamaterial can block the elastic waves propagation in a fairly wide frequency range within 0–20 Hz. The frequency response analysis demonstrates that the proposed metamaterial can effectively attenuate the low frequency vibration. A simplified equivalent mass–spring model is further proposed to analyze the band gap range which agrees well with the finite element results. This model provides a more convenient method to calculate the band gap range. Combining the proposed equivalent mass–spring model with finite element analysis, the effect of material parameters and geometric parameters on the band gap characteristic is investigated. This study can provide new insights for low frequency vibration attenuation.
Microstructures and Tensile Properties of 9Cr-F/M Steel at Elevated Temperatures
Authors: Zhang Guangjie , Zhang Qinggang , Yang Junfeng , Xie Zhuoming , Zhang Linchao , Liu Rui , Li Gang , Wang Hui , Fang Qianfeng , Wang Xianping
Published: February 2022

Tensile properties and microstructure changes under different stress states of tempered 9Cr-F/M steel were characterized using a transmission electron microscope (TEM), electron backscatter diffraction (EBSD), scanning electron microscopy (SEM), Vickers hardness tester, and tensile tester. This tempered steel has a typical lath martensite structure with only a few polygonal ferrites embedded, and M23C6 and MX phases nucleated on the lath boundaries or within the sub-grains. At elevated temperatures, the strength of the steel decreases. However, the elongation at 400 °C is lower than that at room temperature. For the necking zone, tensile deformation made the grain elongated to the direction of applied stress and thus the grain’s cross-section becomes smaller. For samples with rectangular working area cross-section, the deformation in the TD direction was more severe than that in the ND direction, which made the grain elongated in the TD direction. These results can provide some guidance for composition optimization of the 9Cr-F/M steel and facilitate a better understanding of the fracture mechanism under different stress states.
Impact of Adhesive Layer Thickness on the Behavior of Reinforcing Thin-Walled Sigma-Type Steel Beams with CFRP Tapes
Authors: Szewczak Ilona , Rozylo Patryk , Snela Malgorzata , Rzeszut Katarzyna
Published: February 2022

This paper presents selected issues related to the reinforcement of steel element cold-formed with CFRP tapes. The first section of the paper is a review of source literature and a presentation of the basic information on cold-formed thin-walled steel elements and CFRP composite materials, stressing the advantages and disadvantages of using them to reinforce steel structures. Next, the authors present original research on reinforcing bent thin-walled sigma-type steel beams using adhesive CFRP tapes. Reference beams with a cross-section of Σ200 × 70 × 2 and a length of 3 m, reinforced with CFRP tape, were tested in the four-point bending scheme. Then, the paper discusses a developed numerical model that is consistent with the subject matter of the laboratory tests. The developed numerical model was prepared to represent the failure of the connection between the beam and the composite tape. This was followed by a number of numerical analyses in order to determine the optimum adhesive layer that would allow us to achieve the maximum reduction of the displacements and strains in bent thin-walled sigma-type beams. Three thicknesses of the SikaDur adhesive layer were analyzed in the study. Based on the analyzes, it was found that the increase in the thickness of the adhesive layer slightly reduced the strain and displacement in the beams, but caused a significant decrease in the load value, at which damage appeared in the glued joint.
Experimental Identification of the Roles of Fe, Ni and Attapulgite in Nitroreduction and Dechlorination of p-Chloronitrobenzene by Attapulgite-Supported Fe/Ni Nanoparticles
Authors: Liang Jing , Wang Junwen , Liu Hong , Anang Emmanuella , Fan Xianyuan
Published: February 2022

The porous-material loading and noble-metal doping of nanoscale zero-valent iron (nFe) have been widely used as countermeasures to overcome its limitations. However, few studies focused on the experimental identification of the roles of Fe, the carrier and the doped metal in the application of nFe. In this study, the nitroreduction and dechlorination of p-chloronitrobenzene (p-CNB) by attapulgite-supported Fe/Ni nanoparticles (ATP-nFe/Ni) were investigated and the roles of Fe, Ni and attapulgite were examined. The contributions of Ni are alleviating the oxidization of Fe, acting as a catalyst to trigger the conversion of H2 to H*(active hydrogen atom) and promoting electron transfer of Fe. The action mechanisms of Fe in reduction of -NO2 to -NH2 were confirmed to be electron transfer and to produce H2 via corrosion. When H2 is catalyzed to H* by Ni, the production H* leads to the nitroreduction. In additon, H* is also responsible for the dechlorination of p-CNB and its nitro-reduced product, p-chloroaniline. Another corrosion product of Fe, Fe2+, is incapable of acting in the nitroreduction and dechlorination of p-CNB. The roles of attapulgite includes providing an anoxic environment for nFe, decreasing nFe agglomeration and increasing reaction sites. The results indicate that the roles of Fe, Ni and attapulgite in nitroreduction and dechlorination of p-CNB by ATP-nFe/Ni are crucial to the application of iron-based technology.
Screen-Printed Structures from a Highly Conductive Mildly Oxidized Graphene Suspension for Flexible Electronics
Authors: Vasileva Fedora , Popov Vasiliy , Antonova Irina , Smagulova Svetlana
Published: February 2022

In this study, the screen-printed flexible humidity sensor and supercapacitor structures from a suspension of mildly oxidized graphene (MOG) was obtained. MOG suspension with a low atomic oxygen content (~20%) was synthesized by electrochemical exfoliation of natural graphite in an aqueous solution of ammonium sulfate. MOG films (average thickness 5 μm) with a surface resistance of 102–103 kΩ/sq were obtained by screen printing on a flexible substrate. The thermal reduction of MOG films at 200 °C reduced the surface resistance to 1.5 kΩ/sq. The laser reduction with a 474 nm and 200 mW solid-state laser reduced the surface resistance to ~0.065 kΩ/sq. Various structures were screen-printed on a flexible substrate for a variety of flexible electronics applications. The structures representing a flat supercapacitor had an average specific capacitance of ~6 μF/cm2. The tensile deformations occurring during bending reduced the capacitance by 40% at a bending radius of 2 mm. Humidity sensing structures with sensitivity of 9% were obtained.
In Situ Observation of Microstructural and Inclusions Evolution in High-Strength Steel Deposited Metals with Various Rare Earth Pr Contents
Authors: Zhang Tianli , Wang Weiguang , Ma Yiming , Fang Naiwen , Lin Sanbao , Li Zhuoxin , Kou Sindo
Published: February 2022

The evolution of austenite, acicular ferrite, upper bainite and martensite, and the nucleation of inclusions in the microstructure of high-strength steel deposited metals, was systematically investigated using three kinds of A5.28 E120C-K4 metal-cored wires with various rare earth Pr contents. Grain structure evolution in the process of high temperature, dispersoid characteristics of inclusions and the crystallographic characteristics of the microstructure were assessed. Compared with no addition of Pr6O11, adding 1%Pr6O11 resulted in refined, spheroidized and dispersed inclusions in the deposited metal, leading to an increase in the pinning forces on the grain boundary movement, promoting the formation of an ultra-fine grain structure with an average diameter of 41 μm. The inclusions in the deposited metals were Mn-Si-Pr-Al-Ti-O after Pr addition; the average size of the inclusions in the Pr-containing deposited metals was the smallest, while the number and density of inclusions was the highest. The size of effective inclusions (nucleus of acicular ferrite formation) was mainly in the range of 0.6–1.5 μm. In addition, the content of upper bainite decreased, while the percentage of acicular ferrite increased by 24% due to the increase in the number of effective inclusions in the Pr-containing deposited metals in this study. This study shows that the addition of 1% Pr6O11 is efficient in achieving fine interlaced multiphase with an ultrafine-grained structure, resulting in an enhancement of the impact toughness of the deposited metal.
Methodology to Determine Melt Pool Anomalies in Powder Bed Fusion of Metals Using a Laser Beam by Means of Process Monitoring and Sensor Data Fusion
Authors: Harbig Jana , Wenzler David L. , Baehr Siegfried , Kick Michael K. , Merschroth Holger , Wimmer Andreas , Weigold Matthias , Zaeh Michael F.
Published: February 2022

Additive manufacturing, in particular the powder bed fusion of metals using a laser beam, has a wide range of possible technical applications. Especially for safety-critical applications, a quality assurance of the components is indispensable. However, time-consuming and costly quality assurance measures, such as computer tomography, represent a barrier for further industrial spreading. For this reason, alternative methods for process anomaly detection using process monitoring systems have been developed. However, the defect detection quality of current methods is limited, as single monitoring systems only detect specific process anomalies. Therefore, a new methodology to evaluate the data of multiple monitoring systems is derived using sensor data fusion. Focus was placed on the causes and the appearance of defects in different monitoring systems (photodiodes, on- and off-axis high-speed cameras, and thermography). Based on this, indicators representing characteristics of the process were developed to reduce the data. Finally, deterministic models for the data fusion within a monitoring system and between the monitoring systems were developed. The result was a defect detection of up to 92% of the melt track defects. The methodology was thus able to determine process anomalies and to evaluate the suitability of a specific process monitoring system for the defect detection.
Formation Behavior and Reaction Characteristic of a PTFE/Al Reactive Jet
Authors: Su Chenghai , Guo Huanguo , Zheng Yuanfeng , Xie Jianwen , Wang Haifu
Published: February 2022

To reveal the expansion phenomenon and reaction characteristics of an aluminum particle filled polytetrafluoroethylene (PTFE/Al) reactive jet during the forming process, and to control the penetration and explosion coupling damage ability of the reactive jet, the temperature and density distribution of the reactive jet were investigated by combining numerical simulation and experimental study. Based on the platform of AUTODYN-3D code, the Smoothed Particle Hydrodynamics (SPH) algorithm was used to study the evolution behaviors and distribution regularity of the morphology, density, temperature, and velocity field during the formation process of the reactive composite jet. The reaction characteristic in the forming process was revealed by combining the distribution of the high-temperature zone in numerical simulation and the Differential Scanning Calorimeter/Thermo-Gravimetry (DSC/TG) experiment results. The results show that the distribution of the high-temperature zone of the reactive composite jet is mainly concentrated in the jet tip and the axial direction, and the reactive composite jet tip reacts first. Combining the density distribution in the numerical simulation and the pulsed X-ray experimental results, the forming behavior of the reactive composite jet was analyzed. The results show that the reactive composite jet has an obvious expansion effect, accompanied by a significant decrease in the overall density.
Cooperative Spin Transitions Triggered by Phonons in Metal Complexes Coupled to Molecular Vibrations
Authors: Klokishner Sophia , Ostrovsky Serghei , Palii Andrew , Tsukerblat Boris
Published: February 2022

The present article is a short overview of the theoretical modeling of spin transitions in polymetallic compounds. As distinguished from many insightful reviews on this topic, the present work is focused on the nature of cooperative interaction of the metal clusters in molecular crystals with emphasis at the physical role of molecular vibrations and phonons. The underlying model assumes that the cooperativity is triggered by phonons while the metal centers are coupled to molecular vibrations. It is demonstrated that the suggested model gives a satisfactory description of the observed spin transitions in mono-, bi- and tetranuclear compounds. In the framework of the described approach, we discuss the experimental data on spin crossover in the mononuclear [Fe(ptz)6](BF4)2, binuclear [{Fe(bt)(NCS)2}2bpym] and tetranuclear [Fe(tpa){N(CN)2}]4·(BF4)4·(H2O)2 compounds containing iron ions. The approach is also applied to the description of the charge-transfer-induced spin transition in the [{(Tp)Fe(CN)3}{Co-(PY5Me2)}](CF3SO3) complex.
A Note on Pareto-Type Distributions Parameterized by Its Mean and Precision Parameters
Authors: Bourguignon Marcelo , Gallardo Diego I. , Gómez Héctor J.
Published: February 2022

Pareto-type distributions are well-known distributions used to fit heavy-tailed data. However, the standard parameterizations used for Pareto-type distributions are poorly suited to modeling. On this note, we suggest new parameterizations that are better suited to the purpose. In addition, we propose many regression models where the response variable is Pareto-type distributed using new parameterizations that are indexed by mean and precision parameters. The main motivation for these new parametrizations is the useful interpretation of the regression coefficients in terms of the mean and precision, as is usual in the context of regression models. The parameter estimation of these new models is performed, based on the maximum likelihood paradigm. Some numerical illustrations of the estimators are presented with a discussion of the obtained results. Finally, we illustrate the practicality of the new models by means of two applications to real data sets.
An Efficient Network Intrusion Detection and Classification System
Authors: Ahmad Iftikhar , Ul Haq Qazi Emad , Imran Muhammad , Alassafi Madini O. , AlGhamdi Rayed A.
Published: February 2022

Intrusion detection in computer networks is of great importance because of its effects on the different communication and security domains. The detection of network intrusion is a challenge. Moreover, network intrusion detection remains a challenging task as a massive amount of data is required to train the state-of-the-art machine learning models to detect network intrusion threats. Many approaches have already been proposed recently on network intrusion detection. However, they face critical challenges owing to the continuous increase in new threats that current systems do not understand. This paper compares multiple techniques to develop a network intrusion detection system. Optimum features are selected from the dataset based on the correlation between the features. Furthermore, we propose an AdaBoost-based approach for network intrusion detection based on these selected features and present its detailed functionality and performance. Unlike most previous studies, which employ the KDD99 dataset, we used a recent and comprehensive UNSW-NB 15 dataset for network anomaly detection. This dataset is a collection of network packets exchanged between hosts. It comprises 49 attributes, including nine types of threats such as DoS, Fuzzers, Exploit, Worm, shellcode, reconnaissance, generic, and analysis Backdoor. In this study, we employ SVM and MLP for comparison. Finally, we propose AdaBoost based on the decision tree classifier to classify normal activity and possible threats. We monitored the network traffic and classified it into either threats or non-threats. The experimental findings showed that our proposed method effectively detects different forms of network intrusions on computer networks and achieves an accuracy of 99.3% on the UNSW-NB15 dataset. The proposed system will be helpful in network security applications and research domains.
Chaotic Oscillations in Cascoded and Darlington-Type Amplifier Having Generalized Transistors
Authors: Petrzela Jiri , Rujzl Miroslav
Published: February 2022

This paper describes, based on both numerical and experimental bases, the evolution of chaotic and, in some cases, hyperchaotic attractors within mathematical models of two two-port analog functional blocks commonly used inside radio-frequency systems. The first investigated electronic circuit is known as the cascoded class C amplifier and the second network represents a resonant amplifier with Darlington’s active part. For the analysis of each mentioned block, fundamental configurations that contain coupled generalized bipolar transistors are considered; without driving force or interactions with other lumped circuits. The existence of the structurally stable strange attractors is proved via the high-resolution composition plots of the Lyapunov exponents, numerical sensitivity analysis and captured oscilloscope screenshots.
Precipitation Behavior of O Phase during Continuous Cooling of Ti-22Al-25Nb Alloy
Authors: Li Dong , Zeng Weidong , Zhang Fan , Xu Jianwei , Ma Xiong , Liang Xiaobo
Published: February 2022

The microstructure evolution and formation mechanism of the O phase in a Ti-22Al-25Nb (at.%) orthorhombic alloy resulting from different cooling rates were investigated. The results show that the morphology of the precipitated O phase is significantly affected by the cooling rate. As the cooling rate decreases, the floccular O, composed of many fine acicular O phases, gradually grows into the lamellar O phase. When the alloy is cooled from the B2 phase region, the grain boundary O (OGB) preferentially nucleates at the triple junctions and grain boundaries and forms the flat and the zig-zag OGB according to different cooling rates. The OGB consists of separated, flat OGB parts and unconnected, zig-zag OGB composed of multiple short, separated, flat OGB at a higher cooling rate. The zig-zag OGB presents a connected state due to the sufficient diffusion time at a lower cooling rate. When the alloy is cooled from the (B2 + α2) phase region, the increase of the phase boundary provides favorable conditions for the nucleation of the O phase due to the presence of α2 particles. The precipitated rim O phase appears on the periphery of the α2 particles at lower cooling rates. The analysis indicates that the Widmanstätten intragranular O (OWI) precipitated directly from the B2 phase maintains the plane relation with the parent B2 phase, and the Widmanstätten grain boundary O (OWGB) holds the specific orientation relationship with one of the two adjacent B2 grains. The OGB keeps the specific orientation relationship with one of the B2 grains as much as possible. When it cannot maintain the specific orientation relationship with one of the B2 grains, the OGB maintains a near-orientation relationship with B2 grains on both sides to reduce the nucleation activation energy. Moreover, there can be more than one nucleation site for the O phase on a single B2 grain boundary to form the OGB. The rim O phase formed through a decomposition reaction of α2→α2 (Nb-lean) + O (Nb-rich) is controlled by a diffusional mechanism and maintains a specific orientation relationship, i.e., {001} O//{0001} α2 and <110>O//<112¯0> α2, with the parent α2 particles.
Formation Mechanism and Improvement of Magnetic Particle Inspection Defects in Cr5 Backup Roller Forged Ingot
Authors: Zhang Weifeng , Wang Guanbo , Zhang Yanling , Cheng Guoguang , Zhan Zhonghua
Published: February 2022

Industrial tests and thermodynamic calculations were utilized to investigate the source and formation of magnetic particle inspection defects identified on the near-surface of the Cr5 back-up roll forged ingot, which was used in large cold rolling mills. The results showed that the linear aggregating SiO2-MnO-Al2O3 liquid inclusions up to 3 mm led to the flaw detection failure. SiO2-MnO-Al2O3 liquid inclusions were firstly formed in the inductive furnace. Due to its low contact angle, a huge amount of SiO2-MnO-Al2O3 liquid inclusions were inherited into the forged ingot. The formation of SiO2-MnO-Al2O3 liquid inclusions was attributed to the over-oxidation and relatively low aluminum content in the molten steel, as calculated by Factsage 8.1. Controlling the amount of aluminum in molten steel during the smelting process could modify the formation of SiO2-MnO-Al2O3 and CaO-SiO2-Al2O3 liquid oxide into solid Al2O3 type inclusions that were easily removed. Besides, the CaO-SiO2-Al2O3 liquid oxide could be transformed from CaO-Al2O3 type oxide by the significant loss of aluminum content during the VD process or slag entrapment. Certain content of aluminum in the molten steel could improve the flaw detection caused by the aggregating SiO2-MnO-Al2O3 inclusions effectively.
The Role of Aspartate Transaminase to Platelet Ratio Index (APRI) for the Prediction of Non-Alcoholic Fatty Liver Disease (NAFLD) in Severely Obese Children and Adolescents
Authors: Rigamonti Antonello E. , Bondesan Adele , Rondinelli Eugenia , Cella Silvano G. , Sartorio Alessandro
Published: February 2022

The aspartate transaminase to platelet ratio index (APRI) has been proposed as an easy-to-use biochemical marker in obese adults with non-alcoholic fatty liver disease (NAFLD) and non-alcoholic steatotic hepatitis (NASH). The objective of the present study was to evaluate the clinical and predictive value of APRI in a paediatric obese population. Seven hundred fifty-seven obese children and adolescents (BMI standard deviation score, SDS: >2.0; age range: 10–18.5 years), not consuming alcohol and without hepatitis B or C, were recruited after having been screened for NAFLD by ultrasonography. A series of demographic, biochemical and clinical parameters was compared between the two subgroups (with or without NAFLD); the same parameters were correlated with APRI; and finally, univariable and multivariable logistic regression was used to evaluate the predictors of NAFLD. NAFLD was diagnosed in about 39% of the entire paediatric population, predominantly in males and in subjects suffering from metabolic syndrome. APRI was correlated with the waist circumference (WC), high-density lipoprotein cholesterol (HDL-C), uric acid, total bilirubin, C reactive protein (CRP) and systolic blood pressure (SBP). Furthermore, APRI was higher in males than females, but independent from steatosis severity and metabolic syndrome. With the univariable analysis, the BMI SDS, triglycerides (TG), insulin, homeostatic model assessment for insulin resistance (HOMA-IR), APRI, uric acid and metabolic syndrome were positive predictors of NAFLD, with female sex being negative predictor. At multivariable analysis; however, only BMI SDS, TG, HOMA-IR and APRI were positive predictors of NAFLD, with female sex being a negative predictor. The accuracy of APRI as a biochemical marker of NAFLD was about 60%.In conclusion, in a large (Italian) paediatric obese population, parameters, such as BMI SDS, TG, HOMA-IR and APRI, were positive predictors of NAFLD, with female sex being a negative predictor and most of the prediction explained by APRI. Nevertheless, APRI appears to be a simple biochemical marker of liver injury rather than of NAFLD/NASH and, moreover, is endowed with a limited accuracy for the prediction/diagnosis of NAFLD.
Bacterial Antagonistic Species of the Pathogenic Genus Legionella Isolated from Cooling Tower
Authors: Paranjape Kiran , Lévesque Simon , Faucher Sébastien P.
Published: February 2022

Legionella pneumophila is the causative agent of Legionnaires’ disease, a severe pneumonia. Cooling towers are a major source of large outbreaks of the disease. The growth of L. pneumophila in these habitats is influenced by the resident microbiota. Consequently, the aim of this study was to isolate and characterize bacterial species from cooling towers capable of inhibiting several strains of L. pneumophila and one strain of L. quinlivanii. Two cooling towers were sampled to isolate inhibiting bacterial species. Seven inhibitory isolates were isolated, through serial dilution plating and streaking on agar plates, belonging to seven distinct species. The genomes of these isolates were sequenced to identify potential genetic elements that could explain the inhibitory effect. The results showed that the bacterial isolates were taxonomically diverse and that one of the isolates may be a novel species. Genome analysis showed a high diversity of antimicrobial gene products identified in the genomes of the bacterial isolates. Finally, testing different strains of Legionella demonstrated varying degrees of susceptibility to the antimicrobial activity of the antagonistic species. This may be due to genetic variability between the Legionella strains. The results demonstrate that though cooling towers are breeding grounds for L. pneumophila, the bacteria must contend with various antagonistic species. Potentially, these species could be used to create an inhospitable environment for L. pneumophila, and thus decrease the probability of outbreaks occurring.
DNA Enrichment Methods for Microbial Symbionts in Marine Bivalves
Authors: Li Qiqi , Chen Yu , Zhang Si , Lyu Yuanjiao , Zou Yiyang , Li Jie
Published: February 2022

High-throughput sequencing is a powerful tool used for bivalve symbiosis research, but the largest barrier is the contamination of host DNA. In this work, we assessed the host DNA reduction efficiency, microbial community structure, and microbial diversity of four different sample pre-treatment and DNA extraction methods employed in bivalve gill tissue samples. Metagenomic sequencing showed the average proportions of reads belonging to microorganisms retrieved using PowerSoil DNA extraction kit, pre-treatment with differential centrifugation, pre-treatment with filtration, and HostZERO Microbial DNA kit samples were 2.3 ± 0.6%, 2.5 ± 0.2%, 4.7 ± 1.6%, and 42.6 ± 6.8%, respectively. The microbial DNA was effectively enriched with HostZERO Microbial DNA kit. The microbial communities revealed by amplicon sequencing of the 16S rRNA gene showed the taxonomic biases by using four different pre-treatment and DNA extraction methods. The species diversities of DNA samples extracted with the PowerSoil DNA extraction kit were similar, while lower than DNA samples extracted with HostZERO Microbial DNA kit. The results of this study emphasized the bias of these common methods in bivalve symbionts research and will be helpful to choose a fit-for-purpose microbial enrichment strategy in future research on bivalves or other microbe–invertebrate symbioses.
RNA Sequencing Reveals Widespread Transcription of Natural Antisense RNAs in Entamoeba Species
Authors: Mornico Damien , Hon Chung-Chau , Koutero Mikael , Weber Christian , Coppée Jean-Yves , Clark C Graham , Dillies Marie-Agnes , Guillen Nancy
Published: February 2022

Entamoeba is a genus of Amoebozoa that includes the intestine-colonizing pathogenic species Entamoeba histolytica. To understand the basis of gene regulation in E. histolytica from an evolutionary perspective, we have profiled the transcriptomes of its closely related species E. dispar, E. moshkovskii and E. invadens. Genome-wide identification of transcription start sites (TSS) and polyadenylation sites (PAS) revealed the similarities and differences of their gene regulatory sequences. In particular, we found the widespread initiation of antisense transcription from within the gene coding sequences is a common feature among all Entamoeba species. Interestingly, we observed the enrichment of antisense transcription in genes involved in several processes that are common to species infecting the human intestine, e.g., the metabolism of phospholipids. These results suggest a potentially conserved and compact gene regulatory system in Entamoeba.
Mining Exploration, Raw Materials and Production Technologies of Mortars in the Different Civilization Periods in Menorca Island (Spain)
Authors: Columbu Stefano , Depalmas Anna , Brodu Giovanni , Gallello Gianni , Fancello Dario
Published: February 2022

This study deals with the mortars and subordinately rocks collected from the archaeological site of Cap de Forma, that is a “Bien de Interés Cultural” located on a cape along the southeastern coast of Menorca (Balearic Islands, Spain). Cap de Forma consists of different structures belonging to different periods and civilization phases: a fortified settlement of Talaiotic age, built in cyclopean technique and including three rooms and a rainwater cistern; a nearby necropolis of tombs (cuevas) excavated into the cliff; a more recent site occupancy testified by plastering of the cistern; a house-fort (pecheña casa-quartel), a lookout point of the 17th–18th century. Compositional features and mineralogy of mortars and rocks were investigated by optical microscopy and X-ray diffraction. Physical properties (density, porosity, water saturation and water saturation coefficients and mechanical strength) were also determined. This work is aimed at characterizing these archaeologic remains to understand the building technique, the choice of raw materials and possibly their provenance, taking into account the age and civilization they belong to. Results indicate that cocciopesto-rich mortars were used in the cistern watertight and other ancient structures linking from a Roman age. The cocciopesto seems to derive from local pottery even if some evidence would suggest the contrary, whereas the source of the binder is definitely the local Mg-rich limestone. The house-fort was plastered with gypsum-based mortars in the 17th–18th century. The most likely source of raw gypsum was the island of Mallorca where some quarries were opened in the same period. Mechanical and physical tests reveal a strong state of decay that requires conservation actions. This work sheds light on a poorly studied monument, better constraining the different phases of its occupation. Some interesting questions, such as the cocciopesto provenance, are still open.
Sesquiterpenes and Monoterpenes from the Leaves and Stems of Illicium simonsii and Their Antibacterial Activity
Authors: Li Huijuan , Song Xinghui , Li Huiru , Zhu Lifei , Cao Shengbo , Liu Jifeng
Published: February 2022

Two undescribed ether derivatives of sesquiterpenes, 1-ethoxycaryolane-1, 9β-diol (1) and 2-ethoxyclovane-2β, 9α-diol (3), and one new monoterpene glycoside, p-menthane-1α,2α,8-triol-4-O-β-D-glucoside (5), were obtained, together with eight known compounds from the stems and leaves of I. simonsii. Their structures were elucidated by spectroscopic methods. Compounds 1–11 were evaluated for their potency against Staphylococcus aureus and clinical methicillin-resistant S. aureus (MRSA). Among them, compound 3 was weakly active against S. aureus (MIC = 128 μg/mL), and compounds 6 and 7 exhibited good antibacterial activity against S. aureus and MRSA (MICs = 2–8 µg/mL). A primary mechanism study revealed that compounds 6 and 7 could kill bacteria by destroying bacterial cell membranes. Moreover, compounds 6 and 7 were not susceptible to drug resistance development.
Identification of Antibacterial Metabolites from Endophytic Fungus Aspergillus fumigatus, Isolated from Albizia lucidior Leaves (Fabaceae), Utilizing Metabolomic and Molecular Docking Techniques
Authors: Hussein Mai E. , Mohamed Osama G. , El-Fishawy Ahlam M. , El-Askary Hesham I. , El-Senousy Amira S. , El-Beih Ahmed A. , Nossier Eman S. , Naglah Ahmed M. , Almehizia Abdulrahman A. , Tripathi Ashootosh , Hamed Ahmed A.
Published: February 2022

The rapid spread of bacterial infection caused by Staphylococcus aureus has become a problem to public health despite the presence of past trials devoted to controlling the infection. Thus, the current study aimed to explore the chemical composition of the extract of endophytic fungus Aspergillus fumigatus, isolated from Albizia lucidior leaves, and investigate the antimicrobial activity of isolated metabolites and their probable mode of actions. The chemical investigation of the fungal extract via UPLC/MS/MS led to the identification of at least forty-two metabolites, as well as the isolation and complete characterization of eight reported metabolites. The antibacterial activities of isolated metabolites were assessed against S. aureus using agar disc diffusion and microplate dilution methods. Compounds ergosterol, helvolic acid and monomethyl sulochrin-4-sulphate showed minimal inhibitory concentration (MIC) values of 15.63, 1.95 and 3.90 µg/mL, respectively, compared to ciprofloxacin. We also report the inhibitory activity of the fungal extract on DNA gyrase and topoisomerase IV, which led us to perform molecular docking using the three most active compounds isolated from the extract against both enzymes. These active compounds had the required structural features for S. aureus DNA gyrase and topoisomerase IV inhibition, evidenced via molecular docking.
Synthesis of Terpineol from Alpha-Pinene Catalyzed by α-Hydroxy Acids
Authors: Meng Zhong-Lei , Wen Ru-Si , Huang Xiao-Rui , Qin Rong-Xiu , Hu Yi-Ming , Zhou Yong-Hong
Published: February 2022

We report the use of five alpha-hydroxy acids (citric, tartaric, mandelic, lactic and glycolic acids) as catalysts in the synthesis of terpineol from alpha-pinene. The study found that the hydration rate of pinene was slow when only catalyzed by alpha-hydroxyl acids. Ternary composite catalysts, composed of AHAs, phosphoric acid, and acetic acid, had a good catalytic performance. The reaction step was hydrolysis of the intermediate terpinyl acetate, which yielded terpineol. The optimal reaction conditions were as follows: alpha-pinene, acetic acid, water, citric acid, and phosphoric acid, at a mass ratio of 1:2.5:1:(0.1–0.05):0.05, a reaction temperature of 70 °C, and a reaction time of 12–15 h. The conversion of alpha-pinene was 96%, the content of alpha-terpineol was 46.9%, and the selectivity of alpha-terpineol was 48.1%. In addition, the catalytic performance of monolayer graphene oxide and its composite catalyst with citric acid was studied, with acetic acid used as an additive.
α-Glucosidase Inhibitory Activity of Fermented Okara Broth Started with the Strain Bacillus amyloliquefaciens SY07
Authors: Gao Yifang , Bian Wenhui , Fang Yuanyuan , Du Peng , Liu Xueting , Zhao Xueru , Li Fengjuan
Published: February 2022

In this work, a new strain of Bacillus amyloliquefaciens SY07 isolated from a traditional fermented soybean food was reported to possess remarkable α-glucosidase inhibitor-producing ability. Different culture media were applied for the proliferation of B. amyloliquefaciens SY07, and it was found that fermented okara broth presented the highest α-glucosidase inhibitory activity, while Luria-Bertani medium showed a negative effect. The extract from fermented okara broth acted in a dose-dependent manner to inhibit α-glucosidase activity, with an IC50 value of 0.454 mg/mL, and main inhibitors in the fermentation extract presented a reversible, uncompetitive pattern according to Lineweaver–Burk plots. Moreover, 1-deoxynojirimycin, a recognized α-glucosidase inhibitor, was found in the extract. Results indicated that B. amyloliquefaciens SY07 could utilize okara, a by-product from the soy processing industry, to generate α-glucosidase inhibitors effectively, and be regarded as a novel excellent microbial candidate for safe, economical production of potential functional foods or ingredients with hypoglycemic effect.
Uncommon Terpenoids from Salvia Species: Chemistry, Biosynthesis and Biological Activities
Authors: Hafez Ghoran Salar , Taktaz Fatemeh , Mozafari Ali Akbar , Tunçtürk Murat , Sekeroglu Nazim , Kijjoa Anake
Published: February 2022

The search for new bioactive compounds from plant sources has been and continues to be one of the most important fields of research in drug discovery. However, Natural Products research has continuously evolved, and more and more has gained a multidisciplinary character. Despite new developments of methodologies and concepts, one intriguing aspect still persists, i.e., different species belonging to the same genus can produce different secondary metabolites, whereas taxonomically different genera can produce the same compounds. The genus Salvia L. (Family Lamiaceae) comprises myriad distinct medicinal herbs used in traditional medicine worldwide that show different pharmacological activities due to the presence of a variety of interesting specialized metabolites, including mono-, sesqui-, di-, sester-, tri-, tetra-, and higher terpenoids as well as phenylpropanoids, phenolic acid derivatives, lignans, flavonoids, and alkaloids. We herein summarize the research progress on some uncommon terpenoids, isolated from members of the genus Salvia, which are well recognized for their potential pharmacological activities. This review also provides a current knowledge on the biosynthesis and occurrence of some interesting phytochemicals from Salvia species, viz. C23-terpenoids, sesterterpenoids (C25), dammarane triterpenoids (C30), and uncommon triterpenoids (C20+C10). The study was carried out by searching various scientific databases, including Elsevier, ACS publications, Taylor and Francis, Wiley Online Library, MDPI, Springer, Thieme, and ProQuest. Therefore, 106 uncommon terpenoids were identified and summarized. Some of these compounds possessed a variety of pharmacological properties, such as antibacterial, antiviral, antiparasitic, cytotoxic and tubulin tyrosine ligase inhibitory activities. Due to the lack of pharmacological information for the presented compounds gathered from previous studies, biological investigation of these compounds should be reinvestigated.
Magnetic and Luminescence Properties of 8-Coordinate Holmium(III) Complexes Containing 4,4,4-Trifluoro-1-Phenyl- and 1-(Naphthalen-2-yl)-1,3-Butanedionates
Authors: Mautner Franz A. , Bierbaumer Florian , Vicente Ramon , Speed Saskia , Tubau Ánnia , Font-Bardía Mercè , Fischer Roland C. , Massoud Salah S.
Published: February 2022

A new series of mononuclear Ho3+ complexes derived from the β-diketonate anions: 4,4,4-trifluoro-1-phenyl-1,3-butanedioneate (btfa−) and 4,4,4-trifuoro-1-(naphthalen-2-yl)-1,3-butanedionate (ntfa−) have been synthesized, [Ho(btfa)3(H2O)2] (1a), [Ho(ntfa)3(MeOH)2] (1b), (1), [Ho(btfa)3(phen)] (2), [Ho(btfa)3(bipy)] (3), [Ho(btfa)3(di-tbubipy)] (4), [Ho(ntfa)3(Me2bipy)] (5), and [Ho(ntfa)3(bipy)] (6), where phen is 1,10-phenantroline, bipy is 2,2′-bipyridyl, di-tbubipy is 4,4′-di-tert-butyl-2,2′-bipyridyl, and Me2bipy is 4,4′-dimethyl-2,2′-bipyridyl. These compounds have been characterized by elemental microanalysis and infrared spectroscopy as well as single-crystal X-ray difraction for 2–6. The central Ho3+ ions in these compounds display coordination number 8. The luminescence-emission properties of the pyridyl adducts 2–6 display a strong characteristic band in the visible region at 661 nm and a series of bands in the NIR region (excitation wavelengths (λex) of 367 nm for 2–4 and 380 nm for 5 and 6). The magnetic properties of the complexes revealed magnetically uncoupled Ho3+ compounds with no field-induced, single-molecule magnet (SMMs).
Co3Gd4 Cage as Magnetic Refrigerant and Co3Dy3 Cage Showing Slow Relaxation of Magnetisation
Authors: Sheikh Javeed Ahmad , Jena Himanshu Sekhar , Konar Sanjit
Published: February 2022

Two structurally dissimilar 3d-4f cages having the formulae [(CoIII)3Gd4(μ3-OH)2(CO3) (O2CtBu)11(teaH)3]·5H2O (1) and [(CoIII)3Dy3(μ3-OH)4(O2CtBu)6(teaH)3]·(NO3)2·H2O (2) have been isolated under similar reaction conditions and stoichiometry of the reactants. The most important factor for structural diversity seems to be the incorporation of one μ3-carbonate anion in 1 and not in 2. Co atoms are in a +3 oxidation state in both complexes, as shown by the Bond Valence Sum (BVS) calculations and bond lengths, and as further supported by magnetic measurements. Co3Gd4 displays a significant magnetocaloric effect (−∆Sm = 25.67 J kg−1 K−1), and Co3Dy3 shows a single molecule magnet (SMM) behavior.