bluuebunny/crossref_metadata_2025 huggingface dataset:
Knowledge-Enhanced Graph Attention Network for Fact Verification
Authors: Chen Chonghao , Zheng Jianming , Chen Honghui
Published: August 2021

Fact verification aims to evaluate the authenticity of a given claim based on the evidence sentences retrieved from Wikipedia articles. Existing works mainly leverage the natural language inference methods to model the semantic interaction of claim and evidence, or further employ the graph structure to capture the relation features between multiple evidences. However, previous methods have limited representation ability in encoding complicated units of claim and evidences, and thus cannot support sophisticated reasoning. In addition, a limited amount of supervisory signals lead to the graph encoder could not distinguish the distinctions of different graph structures and weaken the encoding ability. To address the above issues, we propose a Knowledge-Enhanced Graph Attention network (KEGA) for fact verification, which introduces a knowledge integration module to enhance the representation of claims and evidences by incorporating external knowledge. Moreover, KEGA leverages an auxiliary loss based on contrastive learning to fine-tune the graph attention encoder and learn the discriminative features for the evidence graph. Comprehensive experiments conducted on FEVER, a large-scale benchmark dataset for fact verification, demonstrate the superiority of our proposal in both the multi-evidences and single-evidence scenarios. In addition, our findings show that the background knowledge for words can effectively improve the model performance.
Understanding Consumer Stockpiling during the COVID-19 Outbreak through the Theory of Planned Behavior
Authors: Roșu Maria-Magdalena , Ianole-Călin Rodica , Dinescu Raluca , Bratu Anca , Papuc Răzvan-Mihail , Cosma Anastasia
Published: August 2021

We use the theory of planned behavior (TPB) to investigate determinants of stockpiling behavior during the COVID-19 lockdown. We analyzed 518 responses to an online survey and used Partial Least Squares Path Modeling (PLS-PM) techniques to estimate relationships between variables. Negative attitude (perceived barriers) and others’ behavior (descriptive social norms) were revealed as significant predictors for both intention to over-purchase and the actual stockpiling behavior. The lack of significance obtained for perceived behavioral control (PBC) is also an important result, strengthening the evidence that factors’ contribution to TPB’s predictive power is strongly context-dependent, respectively that PBC is less relevant in settings dominated by uncertainty. The lack of significance is especially compelling when stockpiling behavior is regarded as deviant conduct from effective consumption. Our findings expand the understanding on the applicability of TPB and offer informed practical suggestions for improving managerial strategies, public and private ones, during extreme events when self-regulation and cognitive control are expedient but hard to achieve.
Stability Analysis of Pseudo-Almost Periodic Solution for a Class of Cellular Neural Network with D Operator and Time-Varying Delays
Authors: Liu Weide , Huang Jianliang , Yao Qinghe
Published: August 2021

Cellular neural networks with D operator and time-varying delays are found to be effective in demonstrating complex dynamic behaviors. The stability analysis of the pseudo-almost periodic solution for a novel neural network of this kind is considered in this work. A generalized class neural networks model, combining cellular neural networks and the shunting inhibitory neural networks with D operator and time-varying delays is constructed. Based on the fixed-point theory and the exponential dichotomy of linear equations, the existence and uniqueness of pseudo-almost periodic solutions are investigated. Through a suitable variable transformation, the globally exponentially stable sufficient condition of the cellular neural network is examined. Compared with previous studies on the stability of periodic solutions, the global exponential stability analysis for this work avoids constructing the complex Lyapunov functional. Therefore, the stability criteria of the pseudo-almost periodic solution for cellular neural networks in this paper are more precise and less conservative. Finally, an example is presented to illustrate the feasibility and effectiveness of our obtained theoretical results.
Phytotherapy as Multi-Hit Therapy to Confront the Multiple Pathophysiology in Non-Alcoholic Fatty Liver Disease: A Systematic Review of Experimental Interventions
Authors: Ore Ayokanmi , Akinloye Oluseyi Adeboye
Published: August 2021

Non-alcoholic fatty liver disease (NAFLD), or metabolic dysfunction-associated fatty liver disease (MAFLD), is a metabolic condition distinguished by fat deposition in the hepatocytes. It has a prevalence of about 25% worldwide and is associated with other conditions such as diabetes mellitus, obesity, hypertension, etc. Background and Objectives: There is currently no approved drug therapy for NAFLD. Current measures in the management of NAFLD include lifestyle modification such as an increase in physical activity or weight loss. Development of NAFLD involves a number of parallel hits: including genetic predisposition, insulin resistance, disordered lipid metabolism, mitochondrial dysfunction, lipotoxicity, oxidative stress, etc. Herbal therapy may have a role to play in the treatment of NAFLD, due to their numerous bioactive constituents and the multiple pharmacological actions they exhibit. Therefore, this systematic review aims to investigate the potential multi-targeting effects of plant-derived extracts in experimental models of NAFLD. Materials and Methods: We performed a systematic search on databases and web search engines from the earliest available date to 30 April 2021, using relevant keywords. The study included articles published in English, assessing the effects of plant-derived extracts, fractions, or polyherbal mixtures in the treatment of NAFLD in animal models. These include their effects on at least disordered lipid metabolism, insulin resistance/type 2 diabetes mellitus (T2DM), and histologically confirmed steatosis with one or more of the following: oxidative stress, inflammation, hepatocyte injury, obesity, fibrosis, and cardiometabolic risks factors. Results: Nine articles fulfilled our inclusion criteria and the results demonstrated the ability of phytomedicines to simultaneously exert therapeutic actions on multiple targets related to NAFLD. Conclusions: These findings suggest that herbal extracts have the potential for effective treatment or management of NAFLD.
Sclerosing Extramedullary Hematopoietic Tumor (SEHT) Mimicking a Malignant Bile Duct Tumor-Case Report and Literature Review
Authors: Dema Sorin , Lazar Fulger , Barna Robert , Dobrescu Amadeus , Dema Alis Liliana Carmen , Popa Oana , Ionita Ioana , Taban Sorina Maria
Published: August 2021

Introduction: Sclerosing Extramedullary Hematopoietic Tumor (SEHT) is a very rare lesion associated with chronic myeloproliferative disorders (CMPD). SEHT can mimic morphologically, both macroscopically and microscopically, a wide variety of tumors/lesions. Case presentation: We present the case of a female patient diagnosed with gallstones for which surgery was decided. Intraoperatively, a malignant tumor of extrahepatic bile ducts was suspected. A frozen section examination raised the suspicion of a mesenchymal tumor or an inflammatory pseudotumor. The histological evaluation of the permanent sections, supplemented with an immunohistochemical investigation (IHC), was the one that established the diagnosis of SEHT, based on the presence of areas of sclerosis, atypical CD31+ megakaryocytes, myeloid and erythroid elements. Conclusions: The authors present the difficulties of a morphological diagnosis on the frozen section and on permanent sections in the absence of relevant clinical information and make a review of the literature data dedicated to the subject.
Highly Proton-Conducting Membranes Based on Poly(arylene ether)s with Densely Sulfonated and Partially Fluorinated Multiphenyl for Fuel Cell Applications
Authors: Huang Tzu-Sheng , Hsieh Tung-Li , Lai Chih-Ching , Wen Hsin-Yi , Huang Wen-Yao , Chang Mei-Ying
Published: August 2021

Series of partially fluorinated sulfonated poly(arylene ether)s were synthesized through nucleophilic substitution polycondensation from three types of diols and superhydrophobic tetra-trifluoromethyl-substituted difluoro monomers with postsulfonation to obtain densely sulfonated ionomers. The membranes had similar ion exchange capacities of 2.92 ± 0.20 mmol g−1 and favorable mechanical properties (Young’s moduli of 1.60–1.83 GPa). The membranes exhibited considerable dimensional stability (43.1–122.3% change in area and 42.1–61.5% change in thickness at 80 °C) and oxidative stability (~55.5%). The proton conductivity of the membranes, higher (174.3–301.8 mS cm−1) than that of Nafion 211 (123.8 mS cm−1), was the percent conducting volume corresponding to the water uptake. The membranes were observed to comprise isolated to tailed ionic clusters of size 15–45 nm and 3–8 nm, respectively, in transmission electron microscopy images. A fuel cell containing one such material exhibited high single-cell performance—a maximum power density of 1.32 W cm2 and current density of >1600 mA cm−2 at 0.6 V. The results indicate that the material is a candidate for proton exchange membranes in fuel cell applications.
Development of Methanol Permselective FAU-Type Zeolite Membranes and Their Permeation and Separation Performances
Authors: Ikeda Ayumi , Abe Chie , Matsuura Wakako , Hasegawa Yasuhisa
Published: August 2021

The separation of non-aqueous mixtures is important for chemical production, and zeolite membranes have great potential for energy-efficient separation. In this study, the influence of the framework structure and composition of zeolites on the permeation and separation performance of methanol through zeolite membranes were investigated to develop a methanol permselective zeolite membrane. As a result, the FAU-type zeolite membrane prepared using a solution with a composition of 10 SiO2:1 Al2O3:17 Na2O:1000 H2O showed the highest permeation flux of 86,600 μmol m−2 s−1 and a separation factor of 6020 for a 10 wt% methanol/methyl hexanoate mixture at 353 K. The membrane showed a molecular sieving effect, reducing the single permeation flux of alcohol with molecular size for single-component alcohols. Moreover, the permeation flux of methanol and the separation factor increased with an increase in the carbon number of the alcohols and methyl esters containing 10 wt% methanol. In this study, the permeation behavior of FAU-type zeolite membranes was also discussed based on permeation data. These results suggest that the FAU-type zeolite membrane has the potential to separate organic solvent mixtures, such as solvent recycling and membrane reactors.
Preparation and Desalination Performance of PA/UiO-66/PES Composite Membranes
Authors: Trinh Dai Xuan , Pham Ngo Nghia , Chammingkwan Patchanee , Taniike Toshiaki
Published: August 2021

UiO-66 nanoparticles are considered highly potential fillers for the application in desalination membranes. In this study, UiO-66 nanoparticles were anchored to PES membrane substrates, which were subsequently subjected to the interfacial polymerization reaction to coat a layer of polyamide (PA) on their surface. For comparison, a blank membrane incorporating no UiO-66 and a reference membrane incorporating ZrO2 (instead of UiO-66) were prepared. All prepared membranes were tested for their desalination performance. The membranes containing UiO-66 were found to outperform the blank and the reference counterparts. The reason for this outperformance is possibly attributed to the hydrophilicity of UiO-66 nanoparticles and the presence of nanochannels in their structure.
A Study on the Weldment Hardening Discrimination Procedure and Improvement of Flux Cored Arc Welding Process of ASTM A553-1 (9% Nickel Steel) Material Using Bead Geometry Distribution
Authors: Park Minho , Kim Jisun , Pyo Changmin , Kim Jaewoong , Chun Kwangsan
Published: August 2021

As a result of strengthened sulfur content standards for ship fuel oil in IMO regulations, major domestic and foreign carriers have a high and growing demand for liquefied natural gas (LNG) powered ships and related equipment. For LNG operation in a cryogenic environment, a storage tank and fuel supply system that uses steel with excellent brittleness and fatigue strength is required. Ships that use LNG have a high vulnerability to explosion and fire. For this reason, 9% Ni is typically used, since a ship requires high quality products with special materials and structural technologies that guarantee operability at cryogenic temperatures. However, there is an urgent need for research to derive a uniform welding quality, since high process difficulty and differences in welding quality related to a welder’s skills can cause a deterioration of the weld quality in the 9% Ni steel welding process. For 9% Ni steel, the higher the dilution ratio of the base metal, the lower the strength. In order to secure the required strength, excessive dilution of the base metal should be avoided, and the relationship between dilution ratio and strength should be investigated. According to previous research, if it exceeds 25% it may be lower than the API standard of 363 MPa for hardening welds. Therefore, in this study, the flux cored arc welding process is performed by establishing criteria that can be evaluated based on the SVM method in order to determine the structure of the weld to be cured according to the dilution rate of the base metal. We would like to propose a multipurpose optimization algorithm to ensure uniform quality of 9% Ni steel.
Modelling of Hot Flow Stress of Duplex Steel in Dependence of Microstructure Using the Rule of Mixture
Authors: Quadfasel Angela , Nietsch Jürgen A. , Teller Marco , Hirt Gerhard
Published: August 2021

The ferrite fraction and phase distribution of duplex steels depend strongly on the temperature evolution during hot deformation and are correlated to different mechanical behaviors during hot deformation as well as cold deformation. Therefore, the control of microstructure evolution during hot forming is relevant for target-oriented material design. In flow stress modelling for hot forming, the influence of microstructure beyond the ferrite fraction is often neglected. In the present work, a new method is demonstrated to also consider the influence of grain size in flow stress modelling. For this purpose, different initial microstructures with different ferrite fractions and phase distribution were tested in compression tests at 1100 °C and 0.1 s−1. The microstructure was analyzed before and after forming and it was observed that the differences in ferrite fractions vanished during the compression tests. Those microstructure data were used in a model including a rule of mixture and Hall–Petch relationship to extract the single-phase flow curves of ferrite and austenite. Based on the flow stress of the single phases, in combination with ferrite fraction and individual grain size, the flow curves of the different material conditions were calculated and the concurrent influence of ferrite fraction and phase distance on the mechanical behavior was discussed.
Corrosion Behavior of CW6MC Nickel Cast Alloy (Inconel 625) Welded by Shielded Metal Arc Welding
Authors: Vacchi Guilherme dos Santos , Silva Rodrigo , Kugelmeier Cristie Luis , Martins Júnior Claudio Beserra , Dainezi Isabela , Alano José Henrique , Mendes Filho Anibal de Andrade , Ramos Osório Wislei Riuper , Della Rovere Carlos Alberto
Published: August 2021

The aim of this study concerns the effect of multi-pass shielded metal arc welding (SMAW) on the corrosion behavior of CW6MC cast nickel alloy. Using optical and SEM techniques the welded joint is analyzed. Vickers microhardness mapping and potentiodynamic polarization in NaCl and H2SO4 solutions are also evaluated. Both the Laves phase and NbC-type carbides are identified in the base metal (BM) and weld metal (WM) regions. The main microstructural difference observed between these regions is the morphology aspect and fineness of the dendritic arrays. The welding process promotes the finer columnar grains formation with refined intermetallic particles in the WM than equiaxed grains of the BM, which in turn results in higher microhardness values in the former region. However, no substantial changes were observed in the corrosion behavior between the BM and WM regions, considering both acid and saline media. Nevertheless, during the multi-pass SMAW process, some non-metallic micrometric inclusions (Mo and S-rich regions) can be constituted to occur in the WM region. This is associated with a significant drop in the corrosion performance of this region when the electrochemical tests are evaluated.
Acyl-Coenzyme A: Cholesterol Acyltransferase (ACAT) in Cholesterol Metabolism: From Its Discovery to Clinical Trials and the Genomics Era
Authors: Hai Qimin , Smith Jonathan D.
Published: August 2021

The purification and cloning of the acyl-coenzyme A: cholesterol acyltransferase (ACAT) enzymes and the sterol O-acyltransferase (SOAT) genes has opened new areas of interest in cholesterol metabolism given their profound effects on foam cell biology and intestinal lipid absorption. The generation of mouse models deficient in Soat1 or Soat2 confirmed the importance of their gene products on cholesterol esterification and lipoprotein physiology. Although these studies supported clinical trials which used non-selective ACAT inhibitors, these trials did not report benefits, and one showed an increased risk. Early genetic studies have implicated common variants in both genes with human traits, including lipoprotein levels, coronary artery disease, and Alzheimer’s disease; however, modern genome-wide association studies have not replicated these associations. In contrast, the common SOAT1 variants are most reproducibly associated with testosterone levels.
Road to Acquisition: Preparing a MEMS Microphone Array for Measurement of Fuselage Surface Pressure Fluctuations
Authors: Ahlefeldt Thomas , Haxter Stefan , Spehr Carsten , Ernst Daniel , Kleindienst Tobias
Published: August 2021

Preparing and pre-testing experimental setups for flight tests is a lengthy but necessary task. One part of this preparation is comparing newly available measurement technology with proven setups. In our case, we wanted to compare acoustic Micro-Electro-Mechanical Systems (MEMS) to large and proven surface-mounted condenser microphones. The task started with the comparison of spectra in low-speed wind tunnel environments. After successful completion, the challenge was increased to similar comparisons in a transonic wind tunnel. The final goal of performing in-flight measurements on the outside fuselage of a twin-engine turboprop aircraft was eventually achieved using a slim array of 45 MEMS microphones with additional large microphones installed on the same carrier to drawn on for comparison. Finally, the array arrangement of MEMS microphones allowed for a complex study of fuselage surface pressure fluctuations in the wavenumber domain. The study indicates that MEMS microphones are an inexpensive alternative to conventional microphones with increased potential for spatially high-resolved measurements even at challenging experimental conditions during flight tests.
On the Efficiency of a Piezoelectric Energy Harvester under Combined Aeroelastic and Base Excitation
Authors: Stamatellou Antiopi-Malvina , Kalfas Anestis I.
Published: August 2021

A flutter-type, nonlinear piezoelectric energy harvester was tested in various combinations of aerodynamic and harmonic base excitation to study its power output and efficiency. The commercial polyvinylidene fluoride film transducer LDT1-028K was used in 33 excitation mode. The aerodynamic excitation was created by a centrifugal fan and the base excitation by a cone speaker. The excitations were produced by varying independently the mean airflow velocity and the frequency of base vibration. A capacitive load was used to store the harvested energy. A line laser was employed along with long exposure photography and high-speed video, for the visualization of the piezo film’s mode shapes and the measurement of maximum tip deflection. The harvested power was mapped along with the maximum tip deflection of the piezo-film, and a process of optimally combining the two excitation sources for maximum power harvesting is demonstrated. The energy conversion efficiency is defined by means of electrical power output divided by the elastic strain energy rate of change during oscillations. The efficiency was mapped and correlated with resonance conditions and results from other studies. It was observed that the conversion efficiency is related to the phase difference between excitation and response and tends to decrease as the excitation frequency rises.
Breast Acoustic Parameter Reconstruction Method Based on Capacitive Micromachined Ultrasonic Transducer Array
Authors: Pei Yu , Zhang Guojun , Zhang Yu , Zhang Wendong
Published: August 2021

Ultrasound computed tomography (USCT) systems based on capacitive micromachined ultrasonic transducer (CMUT) arrays have a wide range of application prospects. For this paper, a high-precision image reconstruction method based on the propagation path of ultrasound in breast tissue are designed for the CMUT ring array; that is, time-reversal algorithms and FBP algorithms are respectively used to reconstruct sound speed distribution and acoustic attenuation distribution. The feasibility of this reconstruction method is verified by numerical simulation and breast model experiments. According to reconstruction results, sound speed distribution reconstruction deviation can be reduced by 53.15% through a time-reversal algorithm based on wave propagation theory. The attenuation coefficient distribution reconstruction deviation can be reduced by 61.53% through FBP based on ray propagation theory. The research results in this paper will provide key technological support for a new generation of ultrasound computed tomography systems.
Improving Color Quality of Nanowire White Light-Emitting Diodes with Mn4+ Doped Fluoride Nanosheets
Authors: Vu Thi Hong Quan , Doan Thi Tuyet , Jain Barsha , Velpula Ravi Teja , Pham Tung Cao Thanh , Nguyen Hieu Pham Trung , Nguyen Hoang-Duy
Published: August 2021

A two-dimensional nanostructured fluoride red-emitting phosphor with an excellent quantum yield of ~91% is studied for cost-effective and high-color quality nanowire white light-emitting diodes (WLEDs). K2TiF6:Mn4+ phosphors are synthesized via an emulsification method using surfactants as sodium dodecyl sulphonate and oleic acid. The K2TiF6:Mn4+ phosphors in ultra-thin and nanosheet crystals are observed via scanning electron microscopy and high-resolution transmission electron microscopy. The surfactants are found to play a key role in inhibition of KTFM crystal growth process and stabilization of Mn4+ ions doping into the K2TiF6 host. The prepared phosphors exhibited intensive red emission at approximately 632 nm and excellent thermal stability in the range of 300–500 K upon 460 nm light excitation. Moreover, the K2TiF6:Mn4+ nanosheets were integrated on InGaN/AlGaN nanowire WLEDs for color quality study. The results show that the nanowire WLEDs with red-emitting phosphor exhibit unprecedentedly high color rendering index ~96.4, and correlated color temperature ~4450 K.
The Abundance and Taxonomic Diversity of Filterable Forms of Bacteria during Succession in the Soils of Antarctica (Bunger Hills)
Authors: Kudinova Alina G. , Dolgih Andrey V. , Mergelov Nikita S. , Shorkunov Ilya G. , Maslova Olga A. , Petrova Mayya A.
Published: August 2021

Previous studies have shown that a significant part of the bacterial communities of Antarctic soils is represented by cells passing through filters with pore sizes of 0.2 µm. These results raised new research questions about the composition and diversity of the filterable forms of bacteria (FFB) in Antarctic soils and their role in the adaptation of bacteria to the extreme living conditions. To answer such questions, we analyzed the succession of bacterial communities during incubation of Antarctic soil samples from the Bunger Hills at increased humidity and positive temperatures (5 °C and 20 °C). We determined the total number of viable cells by fluorescence microscopy in all samples and assessed the taxonomic diversity of bacteria by next-generation sequencing of the 16S rRNA gene region. Our results have shown that at those checkpoints where the total number of cells reached the maximum, the FFB fraction reached its minimum, and vice versa. We did not observe significant changes in taxonomic diversity in the soil bacterial communities during succession. During our study, we found that the soil bacterial communities as a whole and the FFB fraction consist of almost the same phylogenetic groups. We suppose rapid transition of the cells of the active part of the bacterial population to small dormant forms is one of the survival strategies in extreme conditions and contributes to the stable functioning of microbial communities in Antarctic soils.
The Potential Application of Endophytes in Management of Stress from Drought and Salinity in Crop Plants
Authors: Verma Hariom , Kumar Dharmendra , Kumar Vinod , Kumari Madhuree , Singh Sandeep Kumar , Sharma Vijay Kumar , Droby Samir , Santoyo Gustavo , White James F. , Kumar Ajay
Published: August 2021

Endophytic microorganisms present inside the host plant play an essential role in host fitness, nutrient supply and stress tolerance. Endophytes are often used in sustainable agriculture as biofertilizers, biopesticides and as inoculants to mitigate abiotic stresses including salinity, drought, cold and pH variation in the soil. In changing climatic conditions, abiotic stresses create global challenges to achieve optimum crop yields in agricultural production. Plants experience stress conditions that involve endogenous boosting of their immune system or the overexpression of their defensive redox regulatory systems with increased reactive oxygen species (ROS). However, rising stress factors overwhelm the natural redox protection systems of plants, which leads to massive internal oxidative damage and death. Endophytes are an integral internal partner of hosts and have been shown to mitigate abiotic stresses via modulating local or systemic mechanisms and producing antioxidants to counteract ROS in plants. Advancements in omics and other technologies have been made, but potential application of endophytes remains largely unrealized. In this review article, we will discuss the diversity, population and interaction of endophytes with crop plants as well as potential applications in abiotic stress management.
The New Generation hDHODH Inhibitor MEDS433 Hinders the In Vitro Replication of SARS-CoV-2 and Other Human Coronaviruses
Authors: Calistri Arianna , Luganini Anna , Mognetti Barbara , Elder Elizabeth , Sibille Giulia , Conciatori Valeria , Del Vecchio Claudia , Sainas Stefano , Boschi Donatella , Montserrat Nuria , Mirazimi Ali , Lolli Marco Lucio , Gribaudo Giorgio , Parolin Cristina
Published: August 2021

Although coronaviruses (CoVs) have long been predicted to cause zoonotic diseases and pandemics with high probability, the lack of effective anti-pan-CoVs drugs rapidly usable against the emerging SARS-CoV-2 actually prevented a promptly therapeutic intervention for COVID-19. Development of host-targeting antivirals could be an alternative strategy for the control of emerging CoVs infections, as they could be quickly repositioned from one pandemic event to another. To contribute to these pandemic preparedness efforts, here we report on the broad-spectrum CoVs antiviral activity of MEDS433, a new inhibitor of the human dihydroorotate dehydrogenase (hDHODH), a key cellular enzyme of the de novo pyrimidine biosynthesis pathway. MEDS433 inhibited the in vitro replication of hCoV-OC43 and hCoV-229E, as well as of SARS-CoV-2, at low nanomolar range. Notably, the anti-SARS-CoV-2 activity of MEDS433 against SARS-CoV-2 was also observed in kidney organoids generated from human embryonic stem cells. Then, the antiviral activity of MEDS433 was reversed by the addition of exogenous uridine or the product of hDHODH, the orotate, thus confirming hDHODH as the specific target of MEDS433 in hCoVs-infected cells. Taken together, these findings suggest MEDS433 as a potential candidate to develop novel drugs for COVID-19, as well as broad-spectrum antiviral agents exploitable for future CoVs threats.
Tick-Borne Pathogens and Diseases in Greece
Authors: Efstratiou Artemis , Karanis Gabriele , Karanis Panagiotis
Published: August 2021

Tick-borne diseases (TBDs) are recognized as a serious and growing public health epidemic in Europe, and are a cause of major losses in livestock production worldwide. This review is an attempt to present a summary of results from studies conducted over the last century until the end of the year 2020 regarding ticks, tick-borne pathogens, and tick-borne diseases in Greece. We provide an overview of the tick species found in Greece, as well as the most important tick-borne pathogens (viruses, bacteria, protozoa) and corresponding diseases in circulation. We also consider prevalence data, as well as geographic and climatic conditions. Knowledge of past and current situations of TBDs, as well as an awareness of (risk) factors affecting future developments will help to find approaches to integrated tick management as part of the ‘One Health Concept’; it will assist in avoiding the possibility of hotspot disease emergencies and intra- and intercontinental transmission. Increased surveillance in Greece is required to ensure clear and effective policies for TBD control.
Genome-Resolved Metagenomic Analyses Reveal the Presence of a Putative Bacterial Endosymbiont in an Avian Nasal Mite (Rhinonyssidae; Mesostigmata)
Authors: Osuna-Mascaró Carolina , Doña Jorge , Johnson Kevin P. , de Rojas Manuel
Published: August 2021

Rhinonyssidae (Mesostigmata) is a family of nasal mites only found in birds. All species are hematophagous endoparasites, which may damage the nasal cavities of birds, and also could be potential reservoirs or vectors of other infections. However, the role of members of Rhinonyssidae as disease vectors in wild bird populations remains uninvestigated, with studies of the microbiomes of Rhinonyssidae being almost non-existent. In the nasal mite (Tinaminyssus melloi) from rock doves (Columba livia), a previous study found evidence of a highly abundant putatively endosymbiotic bacteria from Class Alphaproteobacteria. Here, we expanded the sample size of this species (two different hosts- ten nasal mites from two independent samples per host), incorporated contamination controls, and increased sequencing depth in shotgun sequencing and genome-resolved metagenomic analyses. Our goal was to increase the information regarding this mite species and its putative endosymbiont. We obtained a metagenome assembled genome (MAG) that was estimated to be 98.1% complete and containing only 0.9% possible contamination. Moreover, the MAG has characteristics typical of endosymbionts (namely, small genome size an AT bias). Overall, our results support the presence of a potential endosymbiont, which is the first described for avian nasal mites to date, and improve the overall understanding of the microbiota inhabiting these mites.
Characterizing the Cattle Gut Microbiome in Farms with a High and Low Prevalence of Shiga Toxin Producing Escherichia coli
Authors: Vasco Karla , Nohomovich Brian , Singh Pallavi , Venegas-Vargas Cristina , Mosci Rebekah E. , Rust Steven , Bartlett Paul , Norby Bo , Grooms Daniel , Zhang Lixin , Manning Shannon D.
Published: August 2021

Cattle are the main reservoirs of Shiga toxin producing Escherichia coli (STEC), a major foodborne pathogen associated with acute enteric disease and hemolytic–uremic syndrome in humans. A total of 397 beef and dairy cattle from 5 farms were included in this study, of which 660 samples were collected for 16S rRNA gene sequencing. The microbiota of farms with a high-STEC prevalence (HSP) had greater richness compared to those of farms with a low-STEC prevalence (LSP). Longitudinal analyses showed STEC-shedders from LSP farms had higher microbiome diversity; meanwhile, changes in the microbiome composition in HSP farms were independent of the STEC shedding status. Most of the bacterial genera associated with STEC shedding in dairy farms were also correlated with differences in the percentage of forage in diet and risk factors of STEC carriage such as days in milk, number of lactations, and warm temperatures. Identifying factors that alter the gut microbiota and enable STEC colonization in livestock could lead to novel strategies to prevent fecal shedding and the subsequent transmission to humans.
Enterococcal Infections the First Year after Liver Transplantation—A Prospective Cohort Study
Authors: Rasmussen Daniel B. , Møller Dina L. , Knudsen Andreas D. , Rostved Andreas A. , Knudsen Jenny D. , Rasmussen Allan , Nielsen Susanne D.
Published: August 2021

This study aimed to investigate the incidence of enterococcal infections and determine risk factors associated with enterococcal bloodstream infection (BSI) within the first year post-liver transplantation (LTx). We included 321 adult liver transplant recipients transplanted from 2011 to 2019 in a prospective cohort study. Cumulative incidence of enterococcal infections and risk factors associated with BSI were investigated in a competing risk model and time-updated Cox models, respectively. A total of 223 enterococcal infections were identified in 89 recipients. The cumulative incidences of first enterococcal infection and first enterococcal BSI were 28% (95% CI (23–33)) and 11% (CI (7–14)), respectively. Risk factors associated with enterococcal BSI were previous infections in the biliary tract (HR, 33; CI (15–74); p < 0.001), peritoneum (HR, 8.1; CI (3–23); p < 0.001) or surgical site (HR, 5.5; CI (1.4–22); p = 0.02), recipient age (HR per 10 years increase, 1.2; CI (1.03–1.6); p = 0.03), and cold ischemia time (HR per one hour increase, 1.2; CI (1.1–1.3); p < 0.01). Enterococcal infections are highly prevalent the first year post-LTx, and recipients with enterococcal infections in the biliary tract, peritoneum, or surgical site are at increased risk of BSI. These findings may have implications for the choice of empiric antibiotics early post-LTx.
Availability of Trace Elements in Soil with Simulated Cadmium, Lead and Zinc Pollution
Authors: Rolka Elżbieta , Wyszkowski Mirosław
Published: August 2021

The research was based on a pot experiment in which the impact of increasing Cd, Zn and Pb doses on the content of available trace elements in soil was compared. Seven series of trials were designed: 1 (Cd), 2 (Pb), 3 (Zn), 4 (Cd + Pb), 5 (Cd + Zn), 6 (Pb + Zn), 7 (Cd + Pb + Zn). Aside from the control one (without the metals), three increasing levels of contamination were considered within each series. Mobile forms of trace elements (Cd, Pb, Zn, Fe, Mn, Cu, Ni, Co, and Cr) in soil were determined, in addition to which selected physicochemical soil properties—reaction (pH), salinity (EC), hydrolytic acidity (HAC), total exchange bases (TEB)—were identified while cation exchange capacity (CEC), base saturation (BS) and availability factor (AF) were calculated. The application of Cd and Pb to soil resulted in an increase in the share of potentially available forms of these metals in their total content. The availability factor (AF) in the pots polluted with these metals was higher than in the control, in the range 17.5–20.0% for Cd, and 62.8–71.5% for Pb. In turn, the share of Zn mobile forms was comparable in most experimental objects, oscillating around 30%. Moreover, addition to soil of Cd, Pb and Zn usually caused a significant decrease in the content of available forms of Fe, Mn and Cu, and resulted in significantly higher content of available forms of Cr in the soil.
Enhanced Flotation Separation of Cassiterite from Calcite Using Metal-Inorganic Complex Depressant
Authors: Zhao Guanfei , Zhu Dongmei
Published: August 2021

At present, the research on flotation separation of cassiterite and gangue minerals is mainly focused on the development of new collectors or depressants, while the research on combined depressants is rare. In this study, the flotation separation of cassiterite and the typical gangue mineral, calcite, was investigated using the metal-inorganic complex depressant AlSS, composed of aluminum sulfate (Al2(SO4)3) and water glass (Na2SiO3·4H2O). The flotation results indicated that, with the assistance of Al3+, the inhibition effect of SS (water glass) on calcite is significantly enhanced, while the inhibition effect on cassiterite is almost unchanged. The zeta potential and adsorption measurements proved that the formation of the negatively charged colloidal particles composed of Alm(OH)n3m−n and SiOm(OH)n4−2m−n tended to adsorb on the positively charged calcite surface, inhibiting the adsorption of sodium oleate (NaOL), while the adsorption of the colloidal particles on the negatively charged cassiterite surface is relatively less. The contact angle measurements indicate that the contact angle of cassiterite in the NaOL + AlSS solution is obviously larger than that of calcite, which indicates that cassiterite has better floatability in this system. The X-ray photoelectron spectroscopy (XPS) analysis confirms the Al and Si species are adsorbed on the surface of calcite, but not on the cassiterite. In addition, the adsorption of AlSS on cassiterite and calcite changes the chemical environment on the calcite surface, indicating that the adsorption of AlSS on the mineral surface is more inclined to be through a chemical reaction.
The Inhibitory Effect of Sulforaphane on Bladder Cancer Cell Depends on GSH Depletion-Induced by Nrf2 Translocation
Authors: He Canxia , Buongiorno Luigina P. , Wang Wei , Tang Jonathan C. Y. , Miceli Natalizia , Taviano Maria Fernanda , Shan Yujuan , Bao Yongping
Published: August 2021

Sulforaphane (SFN), an isothiocyanate (ITCs) derived from glucosinolate that is found in cruciferous vegetables, has been reported to exert a promising anticancer effect in a substantial amount of scientific research. However, epidemical studies showed inconsistencies between cruciferous vegetable intake and bladder cancer risk. In this study, human bladder cancer T24 cells were used as in vitro model for revealing the inhibitory effect and its potential mechanism of SFN on cell growth. Here, a low dose of SFN (2.5 µM) was shown to promote cell proliferation (5.18–11.84%) and migration in T24 cells, whilst high doses of SFN (>10 µM) inhibited cell growth significantly. The induction effect of SFN on nuclear factor (erythroid-derived 2)-like 2 (Nrf2) expression at both low (2.5 µM) and high dose (10 µM) was characterized by a bell-shaped curve. Nrf2 and glutathione (GSH) might be the underlying mechanism in the effect of SFN on T24 cell growth since Nrf2 siRNA and GSH-depleting agent L-Buthionine-sulfoximine abolished the effect of SFN on cell proliferation. In summary, the inhibitory effect of SFN on bladder cancer cell growth and migration is highly dependent on Nrf2-mediated GSH depletion and following production. These findings suggested that a higher dose of SFN is required for the prevention and treatment of bladder cancer.
An Exchange Mechanism for the Magnetic Behavior of Er3+ Complexes
Authors: Georgiev Miroslav , Chamati Hassan
Published: August 2021

We study the magnetic properties of the erbium based compounds, Na9[Er(W5O18)2] and [(Pc)Er{Pc{N(C4H9)2}8}]·/−, in the framework of an effective spin exchange model involving delocalized electrons occupying molecular orbitals. The calculations successfully reproduce the experimental data available in the literature for the magnetic spectrum, magnetization and molar susceptibility in dc and ac fields. Owing to their similar molecular geometry, the compounds’ magnetic behaviors are interpreted in terms of the same set of active orbitals and thus the same effective spin coupling scheme. For all three complexes, the model predicts a prompt change in the ground state from a Kramer’s doublet at zero fields to a fully polarized quartet one brought about by the action of an external magnetic field without Zeeman splitting. This alteration is attributed to the enhancement of the effect of orbital interactions over the spin exchange as the magnitude of the external magnetic field increases.
Tannin Content in Vitis Species Red Wines Quantified Using Three Analytical Methods
Authors: Watrelot Aude A.
Published: August 2021

Tannin content in red wines is positively correlated with astringency perception and wine grade; however, tannin quantification is one of the main challenges. In this study, tannin content was quantified using three analytical methods in commercial red wines from Vitis vinifera and interspecific cold-hardy hybrids including Marquette, Frontenac, and Petite pearl cultivars. Protein (PP) and methylcellulose precipitation (MCP) methods were compared to a HPLC-DAD method, which is based on the interaction between tannins and a hydrophobic surface (RPC). Frontenac wines were the poorest in tannins and Cabernet sauvignon wines were the richest regardless of the method used. In cold-hardy red wines, the tannin content was higher in Marquette with high alcohol content, which suggested that the tannins were extracted from seeds rather than skins. The high limit of quantification of the PP method and the presence of anthocyanin di-glucosides in cold-hardy wines were parameters suggesting that protein and methylcellulose precipitation methods were neither suitable nor reliable for the quantification of tannins in cold-hardy red wines. The tannin content quantified by RPC was positively correlated to tannin quantified by MCP, suggesting that the RPC method would be relevant for the quantification of tannins in red wines.
Proteomic Advances in Cereal and Vegetable Crops
Authors: Agregán Rubén , Echegaray Noemí , López-Pedrouso María , Aadil Rana Muhammad , Hano Christophe , Franco Daniel , Lorenzo José M.
Published: August 2021

The importance of vegetables in human nutrition, such as cereals, which in many cases represent the main source of daily energy for humans, added to the impact that the incessant increase in demographic pressure has on the demand for these plant foods, entails the search for new technologies that can alleviate this pressure on markets while reducing the carbon footprint of related activities. Plant proteomics arises as a response to these problems, and through research and the application of new technologies, it attempts to enhance areas of food science that are fundamental for the optimization of processes. This review aims to present the different approaches and tools of proteomics in the investigation of new methods for the development of vegetable crops. In the last two decades, different studies in the control of the quality of crops have reported very interesting results that can help us to verify parameters as important as food safety, the authenticity of the products, or the increase in the yield by early detection of diseases. A strategic plan that encourages the incorporation of these new methods into the industry will be essential to promote the use of proteomics and all the advantages it offers in the optimization of processes and the solution of problems.
PLA Electrospun Fibers Reinforced with Organic and Inorganic Nanoparticles: A Comparative Study
Authors: Leonés Adrián , Salaris Valentina , Mujica-Garcia Alicia , Arrieta Marina P. , Lopez Daniel , Lieblich Marcela , Kenny José Maria , Peponi Laura
Published: August 2021

In this work, different poly (lactic acid) (PLA)-based nanocomposite electrospun fibers, reinforced with both organic and inorganic nanoparticles, were obtained. As organic fibers, cellulose nanocrystals, CNC, both neat and functionalized by “grafting from” reaction, chitosan and graphene were used; meanwhile, hydroxyapatite and silver nanoparticles were used as inorganic fibers. All of the nanoparticles were added at 1 wt% with respect to the PLA matrix in order to be able to compare their effect. The main aim of this work was to study the morphological, thermal and mechanical properties of the different systems, looking for differences between the effects of the addition of organic or inorganic nanoparticles. No differences were found in either the glass transition temperature or the melting temperature between the different electrospun systems. However, systems reinforced with both neat and functionalized CNC exhibited an enhanced degree of crystallinity of the electrospun fibers, by up to 12.3%. From a mechanical point of view, both organic and inorganic nanoparticles exhibited a decreased elastic modulus and tensile strength in comparison to neat electrospun PLA fibers, improving their elongation at break. Furthermore, all of the organic and inorganic reinforced systems disintegrated under composting conditions after 35 days.
Synthesis and Biological Evaluation of Amidinourea Derivatives against Herpes Simplex Viruses
Authors: Toscani Anita , Denaro Rossana , Pacheco Sergio Fernando Castillo , Biolatti Matteo , Anselmi Silvia , Dell’Oste Valentina , Castagnolo Daniele
Published: August 2021

Current therapy against herpes simplex viruses (HSV) relies on the use of a few nucleoside antivirals such as acyclovir, famciclovir and valacyclovir. However, the current drugs are ineffective against latent and drug-resistant HSV infections. A series of amidinourea compounds, designed as analogues of the antiviral drug moroxydine, has been synthesized and evaluated as potential non-nucleoside anti-HSV agents. Three compounds showed micromolar activity against HSV-1 and low cytotoxicity, turning to be promising candidates for future optimization. Preliminary mode of action studies revealed that the new compounds act in an early stage of the HSV replication cycle, just after the viral attachment and the entry phase of the infection.
Expanding the Myxochelin Natural Product Family by Nicotinic Acid Containing Congeners
Authors: Frank Nicolas A. , Széles Márió , Akone Sergi H. , Rasheed Sari , Hüttel Stephan , Frewert Simon , Hamed Mostafa M. , Herrmann Jennifer , Schuler Sören M. M. , Hirsch Anna K. H. , Müller Rolf
Published: August 2021

Myxobacteria represent a viable source of chemically diverse and biologically active secondary metabolites. The myxochelins are a well-studied family of catecholate-type siderophores produced by various myxobacterial strains. Here, we report the discovery, isolation, and structure elucidation of three new myxochelins N1–N3 from the terrestrial myxobacterium Corallococcus sp. MCy9049, featuring an unusual nicotinic acid moiety. Precursor-directed biosynthesis (PDB) experiments and total synthesis were performed in order to confirm structures, improve access to pure compounds for bioactivity testing, and to devise a biosynthesis proposal. The combined evaluation of metabolome and genome data covering myxobacteria supports the notion that the new myxochelin congeners reported here are in fact frequent side products of the known myxochelin A biosynthetic pathway in myxobacteria.