bluuebunny/crossref_metadata_2025 huggingface dataset:
Commercial SARS-CoV-2 Targeted, Protease Inhibitor Focused and Protein–Protein Interaction Inhibitor Focused Molecular Libraries for Virtual Screening and Drug Design
Authors: Kralj Sebastjan , Jukič Marko , Bren Urban
Published: December 2021

Since December 2019, the new SARS-CoV-2-related COVID-19 disease has caused a global pandemic and shut down the public life worldwide. Several proteins have emerged as potential therapeutic targets for drug development, and we sought out to review the commercially available and marketed SARS-CoV-2-targeted libraries ready for high-throughput virtual screening (HTVS). We evaluated the SARS-CoV-2-targeted, protease-inhibitor-focused and protein–protein-interaction-inhibitor-focused libraries to gain a better understanding of how these libraries were designed. The most common were ligand- and structure-based approaches, along with various filtering steps, using molecular descriptors. Often, these methods were combined to obtain the final library. We recognized the abundance of targeted libraries offered and complimented by the inclusion of analytical data; however, serious concerns had to be raised. Namely, vendors lack the information on the library design and the references to the primary literature. Few references to active compounds were also provided when using the ligand-based design and usually only protein classes or a general panel of targets were listed, along with a general reference to the methods, such as molecular docking for the structure-based design. No receptor data, docking protocols or even references to the applied molecular docking software (or other HTVS software), and no pharmacophore or filter design details were given. No detailed functional group or chemical space analyses were reported, and no specific orientation of the libraries toward the design of covalent or noncovalent inhibitors could be observed. All libraries contained pan-assay interference compounds (PAINS), rapid elimination of swill compounds (REOS) and aggregators, as well as focused on the drug-like model, with the majority of compounds possessing their molecular mass around 500 g/mol. These facts do not bode well for the use of the reviewed libraries in drug design and lend themselves to commercial drug companies to focus on and improve.
Initiation and Prevention of Biological Damage by Radiation-Generated Protein Radicals
Authors: Gebicki Janusz M. , Nauser Thomas
Published: December 2021

Ionizing radiations cause chemical damage to proteins. In aerobic aqueous solutions, the damage is commonly mediated by the hydroxyl free radicals generated from water, resulting in formation of protein radicals. Protein damage is especially significant in biological systems, because proteins are the most abundant targets of the radiation-generated radicals, the hydroxyl radical-protein reaction is fast, and the damage usually results in loss of their biological function. Under physiological conditions, proteins are initially oxidized to carbon-centered radicals, which can propagate the damage to other molecules. The most effective endogenous antioxidants, ascorbate, GSH, and urate, are unable to prevent all of the damage under the common condition of oxidative stress. In a promising development, recent work demonstrates the potential of polyphenols, their metabolites, and other aromatic compounds to repair protein radicals by the fast formation of less damaging radical adducts, thus potentially preventing the formation of a cascade of new reactive species.
A Molecular Analysis of Cytokine Content across Extracellular Vesicles, Secretions, and Intracellular Space from Different Site-Specific Adipose-Derived Stem Cells
Authors: Santos Jerran , Dalla Penelope V. , Milthorpe Bruce K.
Published: December 2021

Cytokines are multifunctional small proteins that have a vital influence on inflammatory states of tissues and play a role in signalling and cellular control mechanisms. Cytokine expression has primarily been viewed as a form of direct secretion of molecules through an active transportation; however, other forms of active transport such as extracellular vesicles are at play. This is particularly important in stem cells where signalling molecules are key to communication managing the levels of proliferation, migration, and differentiation into mature cells. This study investigated cytokines from intracellular content, direct cellular secretions, and extracellular vesicles from adult adipose-derived stem cells isolated from three distinct anatomical locations: abdomen, thigh, and chin. The cells were cultured investigated using live cell microscopy, cytokine assays, and bioinformatics analysis. The cytokines quantified and examined from each sample type showed a distinct difference between niche areas and sample types. The varying levels of TNF-alpha, IL-6 and IL-8 cytokines were shown to play a crucial role in signalling pathways such as MAPK, ERK1/2 and JAK-STAT in cells. On the other hand, the chemotactic cytokines IL-1rn, Eotaxin, IP-10 and MCP-1 showed the most prominent changes across extracellular vesicles with roles in noncanonical signalling. By examining the local and tangential roles of cytokines in stem cells, their roles in signalling and in regenerative mechanisms may be further understood.
Clinical Significance of Stem Cell Biomarkers EpCAM, LGR5 and LGR4 mRNA Levels in Lymph Nodes of Colon Cancer Patients
Authors: AbdelMageed Manar , Ismail Hager Tarek H. , Olsson Lina , Lindmark Gudrun , Hammarström Marie-Louise , Hammarström Sten , Sitohy Basel
Published: December 2021

The significance of cancer stem cells (CSCs) in initiation and progression of colon cancer (CC) has been established. In this study, we investigated the utility of measuring mRNA expression levels of CSC markers EpCAM, LGR5 and LGR4 for predicting survival outcome in surgically treated CC patients. Expression levels were determined in 5 CC cell lines, 66 primary CC tumors and 382 regional lymph nodes of 121 CC patients. Prognostic relevance was determined using Kaplan-Meier survival and Cox regression analyses. CC patients with lymph nodes expressing high levels of EpCAM, LGR5 or LGR4 (higher than a clinical cutoff of 0.07, 0.06 and 2.558 mRNA copies/18S rRNA unit, respectively) had a decreased mean survival time of 32 months for EpCAM and 42 months for both LGR5 and LGR4 at a 12-year follow-up (p = 0.022, p = 0.005 and p = 0.011, respectively). Additional patients at risk for recurrence were detected when LGR5 was combined with the biomarkers CXCL17 or CEA plus CXCL16. In conclusion, the study underscores LGR5 as a particularly useful prognostic biomarker and illustrates the strength of combining biomarkers detecting different subpopulations of cancer cells and/or cells in the tumor microenvironment for predicting recurrence.
Acetylsalicylic Acid Reduces Passive Aortic Wall Stiffness and Cardiovascular Remodelling in a Mouse Model of Advanced Atherosclerosis
Authors: Roth Lynn , Rombouts Miche , Schrijvers Dorien M. , Emini Veseli Besa , Martinet Wim , De Meyer Guido R. Y.
Published: December 2021

Acetylsalicylic acid (ASA) is widely used in secondary prevention of cardiovascular (CV) disease, mainly because of its antithrombotic effects. Here, we investigated whether ASA can prevent the progression of vessel wall remodelling, atherosclerosis, and CV complications in apolipoprotein E deficient (ApoE−/−) mice, a model of stable atherosclerosis, and in ApoE−/− mice with a mutation in the fibrillin-1 gene (Fbn1C1039G+/−), which is a model of elastic fibre fragmentation, accompanied by exacerbated unstable atherosclerosis. Female ApoE−/− and ApoE−/−Fbn1C1039G+/− mice were fed a Western diet (WD). At 10 weeks of WD, the mice were randomly divided into four groups, receiving either ASA 5 mg/kg/day in the drinking water (ApoE−/− (n = 14), ApoE−/−Fbn1C1039G+/− (n = 19)) or plain drinking water (ApoE−/− (n = 15), ApoE−/−Fbn1C1039G+/− (n = 21)) for 15 weeks. ApoE−/−Fbn1C1039G+/− mice showed an increased neutrophil–lymphocyte ratio (NLR) compared to ApoE−/− mice, and this effect was normalised by ASA. In the proximal ascending aorta wall, ASA-treated ApoE−/−Fbn1C1039G+/− mice showed less p-SMAD2/3 positive nuclei, a lower collagen percentage and an increased elastin/collagen ratio, consistent with the values measured in ApoE−/− mice. ASA did not affect plaque progression, incidence of myocardial infarction and survival of ApoE−/−Fbn1C1039G+/− mice, but systolic blood pressure, cardiac fibrosis and hypertrophy were reduced. In conclusion, ASA normalises the NLR, passive wall stiffness and cardiac remodelling in ApoE−/−Fbn1C1039G+/− mice to levels observed in ApoE−/− mice, indicating additional therapeutic benefits of ASA beyond its classical use.
Damage to Olfactory Organs of Adult Zebrafish Induced by Diesel Particulate Matter
Authors: Song Su Jeong , Park Bongkyun , Jo Kyuhyung , Kim Chan-Sik
Published: December 2021

Particulate matter (PM) is an environmental hazard that is associated with various human health risks. The olfactory system is directly exposed to PM; therefore, the influence of PM exposure on olfactory function must be investigated. In this study, we propose a zebrafish olfactory model to evaluate the effects of exposure to diesel particulate matter (DPM), which was labeled Korean diesel particulate matter (KDP20). KDP20 comprises heavy metals and polycyclic aromatic hydrocarbons (PAHs). KDP20 exposed olfactory organs exhibited reduced cilia and damaged epithelium. Olfactory dysfunction was confirmed using an odor-mediated behavior test. Furthermore, the olfactory damage was analyzed using Alcian blue and anti-calretinin staining. KDP20 exposed olfactory organs exhibited histological damages, such as increased goblet cells, decreased cell density, and calretinin level. Quantitative real-time polymerase chain reaction (qRT-PCR) revealed that PAHs exposure related genes (AHR2 and CYP1A) were upregulated. Reactive oxidation stress (ROS) (CAT) and inflammation (IL-1B) related genes were upregulated. Furthermore, olfactory sensory neuron (OSN) related genes (OMP and S100) were downregulated. In conclusion, KDP20 exposure induced dysfunction of the olfactory system. Additionally, the zebrafish olfactory system exhibited a regenerative capacity with recovery conditions. Thus, this model may be used in future investigating PM-related diseases.
Effect of the Nanoparticle Exposures on the Tomato Bacterial Wilt Disease Control by Modulating the Rhizosphere Bacterial Community
Authors: Jiang Hubiao , Lv Luqiong , Ahmed Temoor , Jin Shaomin , Shahid Muhammad , Noman Muhammad , Osman Hosam-Eldin , Wang Yanli , Sun Guochang , Li Xuqing , Li Bin
Published: December 2021

Ralstonia Solanacearum is one of the most infectious soil-borne bacterial plant pathogens, causing tomato bacterial wilt (TBW). Nanotechnology is an emerging area of research, particularly the application of nanoparticles (NPs) as nanopesticides to manage plant disease is gaining attention nowadays. However, the interaction between NPs and rhizosphere bacterial communities remains largely elusive. This study indicated that metal NPs (CuO, ZnO, and FeO) reduced the incidence of bacterial wilt to varying degrees and affected the composition and structure of the rhizosphere bacterial community. The results revealed that the application of metal oxide NPs can improve the morphological and physiological parameters of TBW infected tomato plants. Among all, CuONPs amendments significantly increase the Chao1 and Shannon index. In the early stage (the second week), it significantly reduces the relative abundance of pathogens. However, the relative abundance of beneficial Streptomyces bacteria increased significantly, negatively correlated with the relative abundance of pathogenic bacteria. In addition, the nano-treatment group will enrich some potential beneficial bacteria such as species from Sphingomonadaceae, Rhizobiaceae, etc. In general, our research provides evidence and strategies for preventing and controlling soil-borne disease tomato bacterial wilt with metal oxide NPs.
A Review on the Role of miR-149-5p in the Carcinogenesis
Authors: Ghafouri-Fard Soudeh , Khoshbakht Tayyebeh , Hussen Bashdar Mahmud , Kadkhoda Sepideh , Taheri Mohammad , Tafrishinejad Arash
Published: December 2021

miR-149 is an miRNA with essential roles in carcinogenesis. This miRNA is encoded by the MIR149 gene on 2q37.3. The miR-149 hairpin produces miR-149-5p and miR-149-3p, which are the “guide” and the sister “passenger” strands, respectively. Deep sequencing experiments have shown higher prevalence of miR-149-5p compared with miR-149-3p. Notably, both oncogenic and tumor suppressive roles have been reported for miR-149-5p. In this review, we summarize the impact of miR-149-5p in the tumorigenesis and elaborate mechanisms of its involvement in this process in a variety of neoplastic conditions based on three lines of evidence, i.e., in vitro, in vivo and clinical settings.
The Potential Antimicrobial Action of Human Mucin 7 15-Mer Peptide and Its Metal Complexes
Authors: Janicka-Kłos Anna , Czapor-Irzabek Hanna , Janek Tomasz
Published: December 2021

Mucin 7 (encoded byMUC7) is a human salivary protein that has a role in the natural immune system. Fragments of mucin 7 exhibit antimicrobial activity against bacteria and yeast. Although the antimicrobial properties of peptides have been known and studied for decades, the exact mechanism of action of antimicrobial peptides (AMPs) is still unclear. It is known that some AMPs require divalent metal ions to activate their activity. Herein, we investigated three 15-mer MUC7 peptides, one of which (mother peptide, sequence, L3) is a synthetic analog of a fragment naturally excised from MUC7 (with His3, His8, and His 14) and its two structural analogs, containing only two histidine residues, His3, His13 and His8, His13 (L2 and L1, respectively). Since there is a correlation between lipophilicity, the presence of metal ions (such as Cu(II) and Zn(II)) and antimicrobial activity of AMP, antimicrobial properties of the studied peptides, as well as their complexes with Cu(II) and Zn(II) ions, were tested for activity against Gram-positive (Enterococcus faecalis, Staphylococcus epidermidis) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa) bacteria and fungi (Candida albicans). The results were correlated with their lipophilicity. Coordination and thermodynamic studies (potentiometry, UV-Vis, CD) revealed the formation of mainly mononuclear complexes in solution for all studied systems with different stability in the physiological pH range.
Early Neural Changes as Underlying Pathophysiological Mechanism in Diabetic Retinopathy
Authors: Cantó Antolín , Martínez Javier , Perini-Villanueva Giuliana , Miranda María , Bejarano Eloy
Published: December 2021

Diabetes mellitus is a chronic disease often accompanied by diabetic retinopathy (DR), one of the most common diabetic complications. DR is an eye condition that causes vision deficiency and often leads to blindness. DR develops when blood vessels damage the retina, the light-sensitive tissue at the back of the eye. Before changes in retinal blood vessel permeability, different molecular and anatomical modifications take place in the retina, including early neural changes. This review will summarize the current status of knowledge regarding pathophysiological mechanisms underlying DR, with a special focus on early neural modifications associated with DR. We describe hyperglycemia-associated molecular and cellular alterations linked to the initiation and progression of DR. We also discuss retinal neurodegeneration as a shared feature in different in vitro and in vivo models of DR. Given how ubiquitous diabetes is and how severe the effects of DR are, we also examine the current pharmacological and genetic approaches for combatting this disease.
Beyond Importance Scores: Interpreting Tabular ML by Visualizing Feature Semantics
Authors: Ghorbani Amirata , Berenbaum Dina , Ivgi Maor , Dafna Yuval , Zou James Y.
Published: December 2021

Interpretability is becoming an active research topic as machine learning (ML) models are more widely used to make critical decisions. Tabular data are one of the most commonly used modes of data in diverse applications such as healthcare and finance. Much of the existing interpretability methods used for tabular data only report feature-importance scores—either locally (per example) or globally (per model)—but they do not provide interpretation or visualization of how the features interact. We address this limitation by introducing Feature Vectors, a new global interpretability method designed for tabular datasets. In addition to providing feature-importance, Feature Vectors discovers the inherent semantic relationship among features via an intuitive feature visualization technique. Our systematic experiments demonstrate the empirical utility of this new method by applying it to several real-world datasets. We further provide an easy-to-use Python package for Feature Vectors.
Designing a Structural Health Monitoring System Accounting for Temperature Compensation
Authors: Caspani Valeria Francesca , Tonelli Daniel , Poli Francesca , Zonta Daniele
Published: December 2021

Structural health monitoring is effective if it allows us to identify the condition state of a structure with an appropriate level of confidence. The estimation of the uncertainty of the condition state is relatively straightforward a posteriori, i.e., when monitoring data are available. However, monitoring observations are not available when designing a monitoring system; therefore, the expected uncertainty must be estimated beforehand. This paper proposes a framework to evaluate the effectiveness of a monitoring system accounting for temperature compensation. This method is applied to the design process of a structural health monitoring system for civil infrastructure. In particular, the focus is on the condition-state parameters representing the structural long-term response trend, e.g., due to creep and shrinkage effects, and the tension losses in prestressed concrete bridges. The result is a simple-to-use equation that estimates the expected uncertainty of a long-term response trend of temperature-compensated response measurements in the design phase. The equation shows that the condition-state uncertainty is affected by the measurement and model uncertainties, the start date and duration of the monitoring activity, and the sampling frequency. We validated our approach on a real-life case study: the Colle Isarco viaduct. We verified whether the pre-posterior estimation of expected uncertainty, performed with the experimented approach, is consistent with the real uncertainty estimated a posteriori based on the monitoring data.
Changes in Alpine Butterfly Communities during the Last 40 Years
Authors: Bonelli Simona , Cerrato Cristiana , Barbero Francesca , Boiani Maria Virginia , Buffa Giorgio , Casacci Luca Pietro , Fracastoro Lorenzo , Provenzale Antonello , Rivella Enrico , Zaccagno Michele , Balletto Emilio
Published: December 2021

Our work aims to assess how butterfly communities in the Italian Maritime Alps changed over the past 40 years, in parallel with altitudinal shifts occurring in plant communities. In 2019, we sampled butterflies at 7 grassland sites, between 1300–1900 m, previously investigated in 2009 and 1978, by semi-quantitative linear transects. Fine-scale temperature and precipitation data elaborated by optimal interpolation techniques were used to quantify climate changes. The changes in the vegetation cover and main habitat alterations were assessed by inspection of aerial photographs (1978–2018/1978–2006–2015). The vegetation structure showed a marked decrease of grassland habitats and an increase of woods (1978–2009). Plant physiognomy has remained stable in recent years (2009–2019) with some local exceptions due to geomorphic disturbance. We observed butterfly ‘species substitution’ indicating a general loss in the more specialised and a general gain in more tolerant elements. We did not observe any decrease in species richness, but rather a change in guild compositions, with (i) an overall increased abundance in some widespread and common lowland species and (ii) the disappearance (or strong decrease) of some alpine (high elevation) species, so that ‘resilience’ could be just delusive. Changes in butterfly community composition were consistent with predicted impacts of local warming.
Myeloid-Derived Suppressor Cells (MDSCs) in Haematology
Authors: Bizymi Nikoleta , Papadaki Helen A.
Published: December 2021

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells with immunomodulating properties, mainly acting by suppressing T-cell responses [...]
Multispectral Imaging Algorithm Predicts Breslow Thickness of Melanoma
Authors: Bozsányi Szabolcs , Varga Noémi , Farkas Klára , Bánvölgyi András , Lőrincz Kende , Lihacova Ilze , Lihachev Alexey , Plorina Emilija , Bartha Áron , Jobbágy Antal , Kuroli Enikő , Paragh György , Holló Péter , Medvecz Márta , Kiss Norbert , Wikonkál Norbert
Published: December 2021

Breslow thickness is a major prognostic factor for melanoma. It is based on histopathological evaluation, and thus it is not available to aid clinical decision making at the time of the initial melanoma diagnosis. In this work, we assessed the efficacy of multispectral imaging (MSI) to predict Breslow thickness and developed a classification algorithm to determine optimal safety margins of the melanoma excision. First, we excluded nevi from the analysis with a novel quantitative parameter. Parameter s’ could differentiate nevi from melanomas with a sensitivity of 89.60% and specificity of 88.11%. Following this step, we have categorized melanomas into three different subgroups based on Breslow thickness (≤1 mm, 1–2 mm and >2 mm) with a sensitivity of 78.00% and specificity of 89.00% and a substantial agreement (κ = 0.67; 95% CI, 0.58–0.76). We compared our results to the performance of dermatologists and dermatology residents who assessed dermoscopic and clinical images of these melanomas, and reached a sensitivity of 60.38% and specificity of 80.86% with a moderate agreement (κ = 0.41; 95% CI, 0.39–0.43). Based on our findings, this novel method may help predict the appropriate safety margins for curative melanoma excision.
Sleep Apnea Classification Algorithm Development Using a Machine-Learning Framework and Bag-of-Features Derived from Electrocardiogram Spectrograms
Authors: Lin Cheng-Yu , Wang Yi-Wen , Setiawan Febryan , Trang Nguyen Thi Hoang , Lin Che-Wei
Published: December 2021

Background: Heart rate variability (HRV) and electrocardiogram (ECG)-derived respiration (EDR) have been used to detect sleep apnea (SA) for decades. The present study proposes an SA-detection algorithm using a machine-learning framework and bag-of-features (BoF) derived from an ECG spectrogram. Methods: This study was verified using overnight ECG recordings from 83 subjects with an average apnea–hypopnea index (AHI) 29.63 (/h) derived from the Physionet Apnea-ECG and National Cheng Kung University Hospital Sleep Center database. The study used signal preprocessing to filter noise and artifacts, ECG time–frequency transformation using continuous wavelet transform (CWT), BoF feature generation, machine-learning classification using support vector machine (SVM), ensemble learning (EL), k-nearest neighbor (KNN) classification, and cross-validation. The time length of the spectrogram was set as 10 and 60 s to examine the required minimum spectrogram window time length to achieve satisfactory accuracy. Specific frequency bands of 0.1–50, 8–50, 0.8–10, and 0–0.8 Hz were also extracted to generate the BoF to determine the band frequency best suited for SA detection. Results: The five-fold cross-validation accuracy using the BoF derived from the ECG spectrogram with 10 and 60 s time windows were 90.5% and 91.4% for the 0.1–50 Hz and 8–50 Hz frequency bands, respectively. Conclusion: An SA-detection algorithm utilizing BoF and a machine-learning framework was successfully developed in this study with satisfactory classification accuracy and high temporal resolution.
Contemporary Fertility-Sparing Management Options of Early Stage Endometrioid Endometrial Cancer in Young Nulliparous Patients
Authors: Aimagambetova Gulzhanat , Terzic Sanja , Laganà Antonio Simone , Bapayeva Gauri , la Fleur Philip , Terzic Milan
Published: December 2021

Incidence of endometrial cancer (EC) has been increasing in recent years, especially in high-income countries. The disease commonly affects peri- and postmenopausal women; however, about 5% of women are diagnosed with EC in their reproductive age. Due to both the increasing incidence of EC among reproductive age women and trends to delayed childbearing, fertility-sparing treatment for young patients with EC has become extremely important for researchers and practitioners. Because the classic treatment with total hysterectomy and bilateral saplingo-oophorectomy is not an appropriate approach for young women demanding fertility preservation, several fertility-sparing options have been developed and summarized in this review. Utilization of different medications and their combination (progestagens, gonadotropin releasing hormones analogues, and metformin in different formulations) are tested and found as efficient for fertility-sparing treatment. New minimally invasive surgical techniques, combined with progestagens, are also confirmed as valuable. There are many novel conservative and surgical treatment approaches under investigation. Assuming that molecular biomarkers can be both diagnostic and prognostic to assist in prediction of response to a certain therapy, prognostic risk groups’ stratification along with specific biomarkers’ identification will ensure low recurrence and decrease mortality rates in young women with EC.
Magnetic Resonance Imaging of the Knee in the Presence of Bridging External Fixation: A Comparative Experimental Evaluation of Four External Fixators, Including Dolphix®
Authors: Addevico Francesco , Simoncini Alberto , Solitro Giovanni , Morandi Massimo Max
Published: December 2021

Performing MR investigation on patients instrumented with external fixators is still controversial. The aim of this study is to evaluate the quality of MR imaging of the knee structures in the presence of bridging external fixators. Different cadaveric lower limbs were instrumented with the MR-conditional external fixators Hofmann III (Stryker, Kalamazoo, MI, USA), Large external Fixator (DePuy Synthes, Raynham, MA, USA), XtraFix (Zymmer, Warsaw, IN, USA) and a newer implant of Ketron Peek CA30 and ERGAL 7075 pins, Dolphix®, (Citieffe, Bologna, Italy). The specimens were MR scanned before and after the instrumentation. The images were subjectively judged by a pool of blinded radiologists and then quantitatively evaluated calculating signal intensity, signal to noise and contrast to noise in the five regions of interest. The area of distortion due to the presence of metallic pins was calculated. All the images were considered equally useful for diagnosis with no differences between devices (p > 0.05). Only few differences in the quantification of images have been detected between groups while the presence of metallic components was the main limit of the procedure. The mean length of the radius of the area of distortion of the pins were 53.17 ± 8.19 mm, 45.07 ± 4.33 mm, 17 ± 5.4 mm and 37.12 ± 10.17 mm per pins provided by Zimmer, Synthes, Citieffe and Stryker, respectively (p = 0.041). The implant of Ketron Peek CA30 and ERGAL 7075 pins showed the smallest distortion area.
Thematic Patterns of Disinformation about COVID-19: The Framing of Checks in the Fato ou Fake and Lupa Agencies
Authors: Teixeira Juliana , Martins Allysson
Published: December 2021

This article, which integrates broader research, aims to identify the fake news patterns propagated in the process of disinformation about COVID-19 that were evaluated by the Brazilian fact-checking agencies Fato or Fake and Lupa. Aiming at this goal, we considered the strategies for spreading false information about the disease from January to September 2020. As a methodology, we used part of the procedures associated with media framing, focusing on the themes and labels of the checked information. Politics and death were the two main issues in misinformation assessed by the agencies, closely followed by themes related to cure and prevention. Personalities were particularly relevant at Lupa. The high frequency of the political issue reveals the ideological polarization that Brazil is experiencing, leading to global health crises such as the new coronavirus pandemic.
The Impact of Board Diversity, CEO Characteristics, and Board Committees on Financial Performance in the Case of Romanian Companies
Authors: Mihail Bogdan Aurelian , Dumitrescu Dalina , Micu Carmen Daniela , Lobda Adriana
Published: December 2021

This paper examines the impact of board diversity, CEO characteristics, and board committees on the financial performance of the companies listed on the Bucharest Stock Exchange (BSE). In order to test the influence of these characteristics, detailed data on more than 70 firms are collected by hand, for the 2016–2020 period, and comprehensive regression models are estimated. The findings show that there are positive effects of board diversity especially with regard to the independent board members. In terms of the board committees, the audit committee is found to have a favourable influence. The regression coefficients imply that a 10% increase in the share of independent board members would be associated with a 0.93% increase in ROE. Based on these findings, it can be argued that improving the corporate governance practices of the companies listed on the BSE would increase the performance and the value of these firms.
Practitioner Perspectives on a Restorative Community: An Inductive Evaluative Study of Conceptual, Pedagogical, and Routine Practice
Authors: Procter-Legg Thomas
Published: December 2021

The purpose of this study is to explore restorative practice (RP) within education, highlighting practitioner views from an inductive evaluative perspective. This is in response to the suggested ambiguity over what constitutes RP in education. Practitioner perspectives are explored, providing an insight into an established restorative school. New data offer further clarity on RP in education by describing embedded practice and highlighting sites for further specific task analysis. Methods include semi-structured questionnaires in the form of employee practice statements, situated within insider research. Eleven practice statements were completed, which were then subject to in-depth thematic analysis. The main findings of this study suggest that RP is clearly understood in this educational setting and participants described a wholistic approach that is part of a wider culture, not just practice as an intervention. Analysis suggests that this can be categorised into the following three themes: Conceptual, Pedagogical and Routine Practice. When used alongside one another, it is suggested that these themes create a restorative paradigm, which is of relevance to the field of education. As such, this paper is designed to provide a useful resource for schools, policy makers and researchers alike.
Effect of Tempering Treatment on Microstructural Evolution and Mechanical Behavior of Heavy-Wall Heat Induction Seamless Bend Pipe
Authors: Hu Juntai , Liu Yu , Wang Ge , Li Qiang , Wen Jianyang , Yan Lijun , Chen Shibo , Gu Yunlong
Published: December 2021

In this paper, the microstructure and mechanical properties of heavy-wall seamless bend pipe after quenching at different tempering temperatures, including 550 °C, 600 °C, 650 °C, and 700 °C, were studied. Microstructure and dislocations observations were characterized by means of an optical microscope, a scanning electron microscope, a transmission electron microscope, and X-ray diffraction. As the tempering temperature increases, the dislocation density in the test steel gradually decreases, and the precipitation behavior of (Nb, V)(C, N) increases. The sample tempered at 650 °C exhibits a granular bainite structure with a dislocation cell structure and a large number of smaller precipitates. The yield platforms of tempered samples at 650 °C and 700 °C are attributed to the pinning effect of the Cottrell atmosphere on dislocations. The sample tempered at 650 °C not only presents the highest strength, but also the highest uniform elongation, which is attributed to the higher strain-hardening rate and instantaneous work-hardening index. This is closely related to the multiplication of dislocations, the interaction between dislocations and dislocations, and the interaction between dislocations and precipitates during plastic deformation of the 650 °C-tempered samples with low dislocation density, which delays the occurrence of necking.
Assessment of the Corrosion Behavior of Friction-Stir-Welded Dissimilar Aluminum Alloys
Authors: Alfattani Rami , Yunus Mohammed , Mohamed Ahmed F. , Alamro Turki , Hassan Mohamed K.
Published: December 2021

The fuel consumption of high-density automobiles has increased in recent years. Aluminum (Al) alloy is a suitable material for weight reduction in vehicles with high ductility and low weight. To address environmental problems in aircraft and maritime applications, in particular rust development and corrosion, the current study assesses the corrosion behavior during friction stir welding (FSW) of two dissimilar Al alloys (AA6061 and AA8011) in various corrosive conditions using salt spraying and submersion tests. Two acidic solutions and one alkaline solution are used in these tests, which are performed at room temperature. The two specimens (AA6061 and AA8011) and the weld region are suspended in a salt spraying chamber and a 5 wt.% NaCl solution is continually sprayed using the circulation pump for 60 h, with the specimens being weighed every 15 h to determine the corrosion rates. According to the salt spraying data, the weld zone has a higher corrosion resistance than the core components. For twenty-eight days, individual specimens are submerged in 3.5 wt.% HCl + H2O and H2SO4 + H2O solutions and seawater. The weld area specimens exhibit stronger corrosion resistance than the base material specimens, and weight loss in the saltwater medium is lower when compared to the other test solutions, according to the corrosion analysis. The scanning electron microscope (SEM) analysis demonstrates that the base metal AA8011 is considerably corroded on its surface.
Nanoceramic Composites for Nuclear Radiation Attenuation
Authors: Hallad Shankar A. , Banapurmath Nagaraj R. , Bhadrakali Avinash S. , Patil Arun Y. , Hunashyal Anand M. , Ganachari Sharanabasava V. , Khan T. M. Yunus , Badruddin Irfan Anjum , Soudagar Manzoore Elahi M. , Kamangar Sarfaraz
Published: December 2021

The development of radiation attenuation materials with lean cross-sections is the need of the hour. However, the inherent threat of radiations accompanying these processes is of major concern. Thus, in an attempt to shield unnecessary radiations, several novel materials have been fabricated alongside the conventional materials available. Yet, there is a need for cost-effective, efficient shielding materials that have good mechanical strength and effective shielding properties. The present work investigates ceramic composite behaviors and radiation shielding capacity reinforced with lead oxide nano-powder. Developed nano-lead-based cement composites were subjected to mechanical tests to determine flexural and compressive strengths to check their suitability for structural applications. Further, the gamma attenuation test of the composites was conducted to determine their neutron absorption capacity. The addition of nano-leadoxide in the control beams was varied from 0.7 to 0.95 and 1 wt.% of the ceramic matrix. The percentage of nano-leadoxide that gives the best results in both enhanced properties and economic aspects was determined to be 0.6 wt.% of the cement.
Radiation Hardness of 4H-SiC P-N Junction UV Photo-Detector
Authors: Sciuto Antonella , Calcagno Lucia , Di Franco Salvatore , Pellegrino Domenico , Selgi Lorenzo , D’Arrigo Giuseppe
Published: December 2021

4H-SiC based p-n junction UV photo-detectors were irradiated with 600 keV He+ in the fluence range of 5 × 1011 ÷ 5 × 1014 ion/cm2 in order to investigate their radiation hardness. The effects of irradiation on the electro-optical performance were monitored in dark condition and in the UV (200 ÷ 400 nm) range, as well as in the visible region confirming the typical visible blindness of unirradiated and irradiated SiC photo-sensors. A decrease of UV optical responsivity occurred after irradiation and two fluence regimes were identified. At low fluence (<1013 ions/cm2), a considerable reduction of optical responsivity (of about 50%) was measured despite the absence of relevant dark current changes. The presence of irradiation induced point defects and then the reduction of photo-generated charge lifetime are responsible for a reduction of the charge collection efficiency and then of the relevant optical response reduction: point defects act as recombination centers for the photo-generated charges, which recombine during the drift/diffusion toward the electrodes. At higher irradiation fluence, the optical responsivity is strongly reduced due to the formation of complex defects. The threshold between low and high fluence is about 100 kGy, confirming the radiation hardness of SiC photo-sensors.
Hybrid RF-Si Xerogels: A Cost-Effective Proposal for Insulator Materials
Authors: Flores-López Samantha L. , Villanueva Sara F. , Rey-Raap Natalia , Arenillas Ana
Published: December 2021

Hybrid xerogels RF/Si were synthesized by controlling the chemical variables involved in the polymerization process (i.e., molar ratios, dilution ratio, catalysts, etc.) and evaluated as insulator materials. Higher insulating performances were recorded for these hybrids compared with their counterparts made from only one of their components (i.e., RF or Si xerogels with similar porous characteristics). The analysis of chemical and structural features correlated with heat transfer methods was useful in understanding the sum of contributions involved in the thermal conductivity of RF/Si xerogels. Variables such as roughness and tortuosity can be used to improve the performance of xerogels from a different perspective. In this way, thermal conductivities of 25 mW/mK were achieved without lengthy process steps or special drying methods. Knowledge of material design and the use of microwave heating during the synthesis allowed us to approach a simple and cost-effective process. These results suggest that the hybrid materials developed in this work are a good starting point for the future of the massive production of insulation materials.
Modeling the Properties of Curcumin Derivatives in Relation to the Architecture of the Siloxane Host Matrices
Authors: Raduly Florentina Monica , Rădiţoiu Valentin , Rădiţoiu Alina , Frone Adriana Nicoleta , Nicolae Cristian Andi , Purcar Violeta , Ispas Georgiana , Constantin Mariana , Răut Iuliana
Published: December 2021

Research in the field of natural dyes has constantly focused on methods of conditioning curcumin and diversifying their fields of use. In this study, hybrid materials were obtained from modified silica structures, as host matrices, in which curcumin dyes were embedded. The influence of the silica network structure on the optical properties and the antimicrobial activity of the hybrid materials was monitored. By modifying the ratio between phenyltriethoxysilane:diphenyldimethoxysilane (PTES:DPDMES), it was possible to evaluate the influence the organosilane network modifiers had on the morphostructural characteristics of nanocomposites. The nanosols were obtained by the sol–gel method, in acid catalysis. The nanocomposites obtained were deposited as films on a glass support and showed a transmittance value (T measured at 550 nm) of around 90% and reflectance of about 11%, comparable to the properties of the uncovered support. For the coatings deposited on PET (polyethylene terephthalate) films, these properties remained at average values of T550 = 85% and R550 = 11% without significantly modifying the optical properties of the support. The sequestration of the dye in silica networks reduced the antimicrobial activity of the nanocomposites obtained, by comparison to native dyes. Tests performed on Candida albicans fungi showed good results for the two curcumin derivatives embedded in silica networks (11–18 mm) by using the spot inoculation method; in comparison, the alcoholic dye solution has a spot diameter of 20–23 mm. In addition, hybrids with the CA derivative were the most effective (halo diameter of 17–18 mm) in inhibiting the growth of Gram-positive bacteria, compared to the curcumin derivative in alcoholic solution (halo diameter of 21 mm). The results of the study showed that the presence of 20–40% by weight DPDMES in the composition of nanosols is the optimal range for obtaining hybrid films that host curcumin derivatives, with potential uses in the field of optical films or bioactive coatings.
Mechanical and Durability Properties of Cementless Concretes Made Using Three Types of CaO-Activated GGBFS Binders
Authors: Yum Woo Sung , Yu Juan , Jeon Dongho , Song Haemin , Sim Sungwon , Kim Do Hoon , Oh Jae Eun
Published: December 2021

This study examined the mechanical and durability properties of CaO-activated ground-granulated blast-furnace slag (GGBFS) concretes made with three different additives (CaCl2, Ca(HCOO)2, and Ca(NO3)2) and compared their properties to the concrete made with 100% Ordinary Portland Cement (OPC). All concrete mixtures satisfied targeted air content and slump ranges but exhibited significantly different mechanical and durability properties. The CaO-activated GGBFS concretes showed different strength levels, depending on the type of additive. The added CaCl2 was the most effective, but Ca(NO3)2 was the least effective at increasing mechanical strength in the CaO-activated GGBFS system. The OPC concrete showed the most excellent freezing–thawing resistance in the durability test, but only the CaO-activated GGBFS concrete with CaCl2 exhibited relatively similar resistance. In addition, the chemical resistance was significantly dependent on the type of acid solution and the type of binder. The OPC concrete had the best resistance in the HCl solution, while all CaO-activated GGBFS concretes had relatively low resistances. However, in the H2SO4 solution, all CaO-activated GGBFS concretes had better resistance than the OPC concrete. All concrete with sulfate ions had ettringite before immersion. However, when they were immersed in HCl solution, ettringite tended to decrease, and gypsum was generated. Meanwhile, the CaO-activated GGBFS concrete with CaCl2 did not change the type of reaction product, possibly due to the absence of ettringite and Ca(OH)2. When immersed in an H2SO4 solution, ettringite decreased, and gypsum increased in all concrete. In addition, the CaO-activated concrete with CaCl2 had a considerable amount of gypsum; it seemed that the dissolved C-S-H and calcite, due to the low pH, likely produced Ca2+ ions, and gypsum formed from the reaction between Ca2+ and H2SO4.
Recycled PET Sand for Cementitious Mortar
Authors: Campanhão Angélica , Marvila Markssuel , de Azevedo Afonso , da Silva Tulane , Fediuk Roman , Vatin Nikolai
Published: December 2021

Cementitious materials cause a great impact on the environment due to the calcination of clinker and the extraction of non-renewable mineral resources. In this work, the replacement of quartz sand from the river by PET sand was evaluated at levels of 10%, 20%, and 30%. Tests were performed in the fresh state through consistency, air retention, density, and incorporated air and in the hardened state for compressive strength, flexural strength, density, capillarity, and water absorption. The results show that PET sand is viable in contents of up to 10%, improving the mechanical properties of the mortar and without compromising its workability and incorporated air properties. Above that level, the loss of properties is very excessive, mainly of workability and incorporated air. The incorporated air of the 30% composition, for example, reaches 24%, an excessive value that impacts the properties of the hardened state, making it impossible to use the material at levels greater than 20%. It is concluded that the use of recycled PET sand is a possibility that contributes to sustainable development, as it reduces the extraction of quartz sand from the river, a non-renewable mineral resource.
Development of Ni-Sr(V,Ti)O3-δ Fuel Electrodes for Solid Oxide Fuel Cells
Authors: Serôdio Costa Bernardo F. , Arias-Serrano Blanca I. , Yaremchenko Aleksey A.
Published: December 2021

A series of strontium titanates-vanadates (STVN) with nominal cation composition Sr1-xTi1-y-zVyNizO3-δ (x = 0–0.04, y = 0.20–0.40 and z = 0.02–0.12) were prepared by a solid-state reaction route in 10% H2–N2 atmosphere and characterized under reducing conditions as potential fuel electrode materials for solid oxide fuel cells. Detailed phase evolution studies using XRD and SEM/EDS demonstrated that firing at temperatures as high as 1200 °C is required to eliminate undesirable secondary phases. Under such conditions, nickel tends to segregate as a metallic phase and is unlikely to incorporate into the perovskite lattice. Ceramic samples sintered at 1500 °C exhibited temperature-activated electrical conductivity that showed a weak p(O2) dependence and increased with vanadium content, reaching a maximum of ~17 S/cm at 1000 °C. STVN ceramics showed moderate thermal expansion coefficients (12.5–14.3 ppm/K at 25–1100 °C) compatible with that of yttria-stabilized zirconia (8YSZ). Porous STVN electrodes on 8YSZ solid electrolytes were fabricated at 1100 °C and studied using electrochemical impedance spectroscopy at 700–900 °C in an atmosphere of diluted humidified H2 under zero DC conditions. As-prepared STVN electrodes demonstrated comparatively poor electrochemical performance, which was attributed to insufficient intrinsic electrocatalytic activity and agglomeration of metallic nickel during the high-temperature synthetic procedure. Incorporation of an oxygen-ion-conducting Ce0.9Gd0.1O2-δ phase (20–30 wt.%) and nano-sized Ni as electrocatalyst (≥1 wt.%) into the porous electrode structure via infiltration resulted in a substantial improvement in electrochemical activity and reduction of electrode polarization resistance by 6–8 times at 900 °C and ≥ one order of magnitude at 800 °C.
Study for Performance Increase of a Extractor Device by Steel Replacement of AISI 304 Steel for AISI 420 Steel
Authors: Júnior Francisco Alves de Lima , Ferreira Ricardo Artur Sanguinetti , Lima Rômulo Rocha de Araújo
Published: December 2021

The performance of an extractor device used in the food industry was studied from the development of structural analysis through computational modeling based on finite elements. These analyses considered the mechanical properties of AISI 304 and 420 stainless steels, in addition to the tribological aspects of the device in operation. Initially, uniaxial tensile tests were carried out according to the ABNT NBR 6892 standard and hardness tests were carried out according to ASTM E384, E92, and E18 standards. From the mechanical tests, structural analyses were carried out numerically on each of the components of the extractor device. After analyzing all the components, the device was assembled to be tested in operation. The wear and service life of devices made from these two materials were evaluated. From this study, it could be concluded that the extractor device made with AISI 420 stainless steel, in addition to having a lower manufacturing cost, suffered less wear and had an increase in service life of up to 650% compared to the extractor device made with steel stainless steel AISI 304.