bluuebunny/crossref_metadata_2025 huggingface dataset:
Flexible Neural Probes with Electrochemical Modified Microelectrodes for Artifact-Free Optogenetic Applications
Authors: Guo Bangbang , Fan Ye , Wang Minghao , Cheng Yuhua , Ji Bowen , Chen Ying , Wang Gaofeng
Published: October 2021

With the rapid increase in the use of optogenetics to investigate nervous systems, there is high demand for neural interfaces that can simultaneously perform optical stimulation and electrophysiological recording. However, high-magnitude stimulation artifacts have prevented experiments from being conducted at a desirably high temporal resolution. Here, a flexible polyimide-based neural probe with polyethylene glycol (PEG) packaged optical fiber and Pt-Black/PEDOT-GO (graphene oxide doped poly(3,4-ethylene-dioxythiophene)) modified microelectrodes was developed to reduce the stimulation artifacts that are induced by photoelectrochemical (PEC) and photovoltaic (PV) effects. The advantages of this design include quick and accurate implantation and high-resolution recording capacities. Firstly, electrochemical performance of the modified microelectrodes is significantly improved due to the large specific surface area of the GO layer. Secondly, good mechanical and electrochemical stability of the modified microelectrodes is obtained by using Pt-Black as bonding layer. Lastly, bench noise recordings revealed that PEC noise amplitude of the modified neural probes could be reduced to less than 50 µV and no PV noise was detected when compared to silicon-based neural probes. The results indicate that this device is a promising optogenetic tool for studying local neural circuits.
Unilateral Intrastriatal 6-Hydroxydopamine Lesion in Mice: A Closer Look into Non-Motor Phenotype and Glial Response
Authors: Mendes-Pinheiro Bárbara , Soares-Cunha Carina , Marote Ana , Loureiro-Campos Eduardo , Campos Jonas , Barata-Antunes Sandra , Monteiro-Fernandes Daniela , Santos Diogo , Duarte-Silva Sara , Pinto Luísa , José Salgado António
Published: October 2021

Parkinson’s disease (PD) is a prevalent movement disorder characterized by the progressive loss of dopaminergic neurons in substantia nigra pars compacta (SNpc). The 6-hydroxydopamine (6-OHDA) lesion is still one of the most widely used techniques for modeling Parkinson’s disease (PD) in rodents. Despite commonly used in rats, it can be challenging to reproduce a similar lesion in mice. Moreover, there is a lack of characterization of the extent of behavioral deficits and of the neuronal loss/neurotransmitter system in unilateral lesion mouse models. In this study, we present an extensive behavioral and histological characterization of a unilateral intrastriatal 6-OHDA mouse model. Our results indicate significant alterations in balance and fine motor coordination, voluntary locomotion, and in the asymmetry’s degree of forelimb use in 6-OHDA lesioned animals, accompanied by a decrease in self-care and motivational behavior, common features of depressive-like symptomatology. These results were accompanied by a decrease in tyrosine hydroxylase (TH)-labelling and dopamine levels within the nigrostriatal pathway. Additionally, we also identify a marked astrocytic reaction, as well as proliferative and reactive microglia in lesioned areas. These results confirm the use of unilateral intrastriatal 6-OHDA mice for the generation of a mild model of nigrostriatal degeneration and further evidences the recapitulation of key aspects of PD, thereby being suitable for future studies beholding new therapeutical interventions for this disease.
Screening for the Active Anti-Inflammatory and Antioxidant Polyphenols of Gaultheria procumbens and Their Application for Standardisation: From Identification through Cellular Studies to Quantitative Determination
Authors: Olszewska Monika Anna , Owczarek Aleksandra , Magiera Anna , Granica Sebastian , Michel Piotr
Published: October 2021

Aerial parts, leaves, and stems of Gaultheria procumbens are polyphenol-rich herbal medicines with anti-inflammatory and antioxidant effects. The present study focused on identifying active markers of the G. procumbens extracts in an integrated approach combining phytochemical and biological capacity tests. The target compounds, representing all classes of Gaultheria polyphenols, were pre-selected by LC-ESI-PDA-MS/MS. For unambiguous identification, the key analytes, including a rare procyanidin trimer (cinnamtannin B-1), miquelianin potassium salt, and two new natural products: quercetin and kaempferol 3-O-β-d-xylopyranosyl-(1→2)-β-d-glucuronopyranosides, were isolated by preparative HPLC and investigated by spectroscopy (HR-ESI-MS, UV-vis, CD, 1D- and 2D-NMR), thiolysis, flame photometry, optical rotation experiments, and absolute configuration studies. The significant contribution of the pre-selected compounds to the biological effects of the extracts was confirmed in vitro: the analytes significantly and in a dose-dependent manner down-regulated the pro-oxidant and pro-inflammatory functions of human neutrophils ex vivo (inhibited the release of reactive oxygen species, IL-1β, TNF-α, and neutrophils elastase, ELA-2), inhibited two key pro-inflammatory enzymes (cyclooxygenase, COX-2, and hyaluronidase), and most of them, except gaultherin, exerted potent direct antioxidant activity (ferric reducing antioxidant power and superoxide anion scavenging capacity). Moreover, cellular safety was confirmed for all compounds by flow cytometry. Eventually, as these mechanisms have been connected to the health benefits of G. procumbens, 11 polyphenols were accepted as active markers, and a simple, accurate, reproducible, and fully validated RP-HPLC-PDA method for standardisation of the target extracts was proposed.
An In Situ FTIR Study of DBD Plasma Parameters for Accelerated Germination of Arabidopsis thaliana Seeds
Authors: Waskow Alexandra , Ibba Lorenzo , Leftley Max , Howling Alan , Ambrico Paolo F. , Furno Ivo
Published: October 2021

Current agricultural practices are not sustainable; however, the non-thermal plasma treatment of seeds may be an eco-friendly alternative to alter macroscopic plant growth parameters. Despite numerous successful results of plasma-seed treatments reported in the literature, the plasma-treatment parameters required to improve plant growth remain elusive due to the plethora of physical, chemical, and biological variables. In this study, we investigate the optimal conditions in our surface dielectric barrier discharge (SDBD) setup, using a parametric study, and attempt to understand relevant species in the plasma treatment using in situ Fourier transform infrared (FTIR) absorption spectroscopy. Our results suggest that treatment time and voltage are key parameters for accelerated germination; however, no clear conclusion on causative agents can be drawn.
Astroglia in Autism Spectrum Disorder
Authors: Gzielo Kinga , Nikiforuk Agnieszka
Published: October 2021

Autism spectrum disorder (ASD) is an umbrella term encompassing several neurodevelopmental disorders such as Asperger syndrome or autism. It is characterised by the occurrence of distinct deficits in social behaviour and communication and repetitive patterns of behaviour. The symptoms may be of different intensity and may vary in types. Risk factors for ASD include disturbed brain homeostasis, genetic predispositions, or inflammation during the prenatal period caused by viruses or bacteria. The number of diagnosed cases is growing, but the main cause and mechanism leading to ASD is still uncertain. Recent findings from animal models and human cases highlight the contribution of glia to the ASD pathophysiology. It is known that glia cells are not only “gluing” neurons together but are key players participating in different processes crucial for proper brain functioning, including neurogenesis, synaptogenesis, inflammation, myelination, proper glutamate processing and many others. Despite the prerequisites for the involvement of glia in the processes related to the onset of autism, there are far too little data regarding the engagement of these cells in the development of ASD.
Diversity of Lipid Function in Atherogenesis: A Focus on Endothelial Mechanobiology
Authors: Kotlyarov Stanislav
Published: October 2021

Atherosclerosis is one of the most important problems in modern medicine. Its high prevalence and social significance determine the need for a better understanding of the mechanisms of the disease’s development and progression. Lipid metabolism and its disorders are one of the key links in the pathogenesis of atherosclerosis. Lipids are involved in many processes, including those related to the mechanoreception of endothelial cells. The multifaceted role of lipids in endothelial mechanobiology and mechanisms of atherogenesis are discussed in this review. Endothelium is involved in ensuring adequate vascular hemodynamics, and changes in blood flow characteristics are detected by endothelial cells and affect their structure and function.
Gene Therapy Strategy for Alzheimer’s and Parkinson’s Diseases Aimed at Preventing the Formation of Neurotoxic Oligomers in SH-SY5Y Cells
Authors: El-Battari Assou , Rodriguez Léa , Chahinian Henri , Delézay Olivier , Fantini Jacques , Yahi Nouara , Di Scala Coralie
Published: October 2021

We present here a gene therapy approach aimed at preventing the formation of Ca2+-permeable amyloid pore oligomers that are considered as the most neurotoxic structures in both Alzheimer’s and Parkinson’s diseases. Our study is based on the design of a small peptide inhibitor (AmyP53) that combines the ganglioside recognition properties of the β-amyloid peptide (Aβ, Alzheimer) and α-synuclein (α-syn, Parkinson). As gangliosides mediate the initial binding step of these amyloid proteins to lipid rafts of the brain cell membranes, AmyP53 blocks, at the earliest step, the Ca2+ cascade that leads to neurodegeneration. Using a lentivirus vector, we genetically modified brain cells to express the therapeutic coding sequence of AmyP53 in a secreted form, rendering these cells totally resistant to oligomer formation by either Aβ or α-syn. This protection was specific, as control mCherry-transfected cells remained fully sensitive to these oligomers. AmyP53 was secreted at therapeutic concentrations in the supernatant of cultured cells, so that the therapy was effective for both transfected cells and their neighbors. This study is the first to demonstrate that a unique gene therapy approach aimed at preventing the formation of neurotoxic oligomers by targeting brain gangliosides may be considered for the treatment of two major neurodegenerative disorders, Alzheimer’s and Parkinson’s diseases.
Helicobacter pylori Neutrophil-Activating Protein Directly Interacts with and Activates Toll-like Receptor 2 to Induce the Secretion of Interleukin-8 from Neutrophils and ATRA-Induced Differentiated HL-60 Cells
Authors: Wen Shao-Hsuan , Hong Zhi-Wei , Chen Chung-Chu , Chang Han-Wen , Fu Hua-Wen
Published: October 2021

Helicobacter pylori neutrophil-activating protein (HP-NAP)-induced production of reactive oxygen species (ROS) by neutrophils and monocytes is regulated by pertussis toxin (PTX)-sensitive G proteins, whereas HP-NAP-induced cytokine secretion by monocytes is mediated by Toll-like receptor 2 (TLR2). However, it is unclear whether TLR2 participates in HP-NAP-induced cytokine secretion by neutrophils. Here, all-trans retinoic acid (ATRA)-induced differentiated HL-60 cells were first employed as a neutrophil model to investigate the molecular mechanisms underlying neutrophil responses to HP-NAP. HP-NAP-induced ROS production in ATRA-induced differentiated HL-60 cells is mediated by the PTX-sensitive heterotrimeric G protein-dependent activation of extracellular signal-regulated kinase 1/2 and p38-mitogen-activated protein kinase, which is consistent with the findings reported for human neutrophils. Next, whether TLR2 participated in HP-NAP-induced secretion of interleukin-8 (IL-8) was investigated in neutrophils and ATRA-induced differentiated HL-60 cells. In both cells, TLR2 participated in HP-NAP-induced IL-8 secretion but not HP-NAP-induced ROS production. Interestingly, PTX-sensitive G proteins also contributed to the HP-NAP-induced secretion of IL-8 from neutrophils and the differentiated HL-60 cells. Our ELISA-based binding assay further revealed the competitive binding of Pam3CSK4, a TLR2 agonist, and HP-NAP to TLR2, which suggests the presence of specific and direct interactions between HP-NAP and TLR2. Thus, HP-NAP directly interacts with and activates TLR2 to induce IL-8 secretion in neutrophils and ATRA-induced differentiated HL-60 cells.
Methotrexate Alters the Expression of microRNA in Fibroblast-like Synovial Cells in Rheumatoid Arthritis
Authors: Iwamoto Naoki , Furukawa Kaori , Endo Yushiro , Shimizu Toshimasa , Sumiyoshi Remi , Umeda Masataka , Koga Tomohiro , Kawashiri Shin-ya , Igawa Takashi , Ichinose Kunihiro , Tamai Mami , Origuchi Tomoki , Kawakami Atsushi
Published: October 2021

We aimed to investigate the effect of methotrexate (MTX) on microRNA modulation in rheumatoid arthritis fibroblast-like synovial cells (RA-FLS). RA-FLS were treated with MTX for 48 h. We then performed miRNA array analysis to investigate differentially expressed miRNAs. Transfection with miR-877-3p precursor and inhibitor were used to investigate the functional role of miR-877-3p in RA-FLS. Gene ontology analysis was used to investigate the cellular processes involving miR-877-3p. The production of cytokines/chemokines was screened by multiplex cytokine/chemokine bead assay and confirmed by ELISA and quantitative real-time PCR. The migratory and proliferative activities of RA-FLS were analyzed by wound healing assay and MKI-67 expression. MTX treatment altered the expression of 13 miRNAs (seven were upregulated and six were downregulated). Among them, quantitative real-time PCR confirmed that miR-877-3p was upregulated in response to MTX (1.79 ± 0.46-fold, p < 0.05). The possible target genes of miR-877-3p in RA-FLS revealed by the microarray analysis were correlated with biological processes. The overexpression of miR-877-3p decreased the production of GM-CSF and CCL3, and the overexpression of miR-877-3p inhibited migratory and proliferative activity. MTX altered the miR-877-3p expression on RA-FLS, and this alteration of miR-877-3p attenuated the abundant production of cytokines/chemokines and proliferative property of RA-FLS.
Mechanotransduction at the Plasma Membrane-Cytoskeleton Interface
Authors: Uray Iván P. , Uray Karen
Published: October 2021

Mechanical cues are crucial for survival, adaptation, and normal homeostasis in virtually every cell type. The transduction of mechanical messages into intracellular biochemical messages is termed mechanotransduction. While significant advances in biochemical signaling have been made in the last few decades, the role of mechanotransduction in physiological and pathological processes has been largely overlooked until recently. In this review, the role of interactions between the cytoskeleton and cell-cell/cell-matrix adhesions in transducing mechanical signals is discussed. In addition, mechanosensors that reside in the cell membrane and the transduction of mechanical signals to the nucleus are discussed. Finally, we describe two examples in which mechanotransduction plays a significant role in normal physiology and disease development. The first example is the role of mechanotransduction in the proliferation and metastasis of cancerous cells. In this system, the role of mechanotransduction in cellular processes, including proliferation, differentiation, and motility, is described. In the second example, the role of mechanotransduction in a mechanically active organ, the gastrointestinal tract, is described. In the gut, mechanotransduction contributes to normal physiology and the development of motility disorders.
Germline POT1 Deregulation Can Predispose to Myeloid Malignancies in Childhood
Authors: Michler Pia , Schedel Anne , Witschas Martha , Friedrich Ulrike Anne , Wagener Rabea , Mehtonen Juha , Brozou Triantafyllia , Menzel Maria , Walter Carolin , Nabi Dalileh , Pearce Glen , Erlacher Miriam , Göhring Gudrun , Dugas Martin , Heinäniemi Merja , Borkhardt Arndt , Stölzel Friedrich , Hauer Julia , Auer Franziska
Published: October 2021

While the shelterin complex guards and coordinates the mechanism of telomere regulation, deregulation of this process is tightly linked to malignant transformation and cancer. Here, we present the novel finding of a germline stop-gain variant (p.Q199*) in the shelterin complex gene POT1, which was identified in a child with acute myeloid leukemia. We show that the cells overexpressing the mutated POT1 display increased DNA damage and chromosomal instabilities compared to the wildtype counterpart. Protein and mRNA expression analyses in the primary patient cells further confirm that, physiologically, the variant leads to a nonfunctional POT1 allele in the patient. Subsequent telomere length measurements in the primary cells carrying heterozygous POT1 p.Q199* as well as POT1 knockdown AML cells revealed telomeric elongation as the main functional effect. These results show a connection between POT1 p.Q199* and telomeric dysregulation and highlight POT1 germline deficiency as a predisposition to myeloid malignancies in childhood.
Observed Risk and User Perception of Road Infrastructure Safety Assessment for Cycling Mobility
Authors: Cafiso Salvatore , Pappalardo Giuseppina , Stamatiadis Nikiforos
Published: October 2021

The opportunities for data collection in smart cities and communities provide new approaches for assessing risk of roadway components. This paper presents and compares two different methodological approaches for cycling safety assessment of objective and perceived risk. Objective risk was derived from speed and direction profiles collected with Global Navigation Satellite System (GNSS) and camera installed on an instrumented bicycle. Safety critical events between cyclists and other road users were identified and linked to five different roadway components. A panel of experts was asked to score the severity of the safety critical events using a Delphi process to reach consensus. To estimate the perceived risk, a web-based survey was provided to the city bicyclist community asking them to score the same five roadway components with a 4-point Likert scale. A comparison between perceived and objective risk classification of the roadway components showed a good agreement when only higher severity conflicts were considered. The research findings support the notion that it is possible to collect information from bicycle probe data that match and user perceptions and thus, utilizing them to take advantage of such data in advancing the goals of in smart cities and communities.
Influence of Cross-Linking Agent Concentration/Beta Radiation Surface Modification on the Micro-Mechanical Properties of Polyamide 6
Authors: Ovsik Martin , Stanek Michal , Dockal Adam , Vanek Jiri , Hylova Lenka
Published: October 2021

This study focuses on the problematic of polyamide 6 containing various concentrations of cross-linking agent that was exposed to electron radiation. It is important to improve the material properties of polymers as much as possible. This endeavor can be realized by numerous methods, one of which is radiation exposure. This study investigates the effect of electron beam radiation in doses ranging from 66 to 132 kGy on the micro-mechanical properties of polymers, specifically polyamide 6 filled with 1, 3 and 5 wt.% of cross-linking agent triallyl isocyanurate (TAIC). The changes in the material brought by the radiation exposure were quantified by measurements of indentation hardness and modulus, which were the main measured micro-mechanical properties. Furthermore, thermo-mechanical analysis (TMA) was chosen to confirm the results of the material cross-linking, while the effect of degradation was investigated by Fourier-transform infrared spectroscopy (FTIR). In pursuit of complete evaluation, the topography of the test subject’s surface was explored by atomic force microscopy (AFM). The optimal concentration/radiation ratio was found in polyamide 6 enriched by 5 wt.% concentration of TAIC, which was irradiated by 132 kGy. Material treated in such a way had its indentation hardness by 33% and indentation modulus improved by 26% in comparison with the untreated material. These results were subsequently confirmed by the TMA and FTIR methods.
Suitability of Engineering-Geological Environment on the Basis of Its Permeability Coefficient: Four Case Studies of Fine-Grained Soils
Authors: Marschalko Marian , Zięba Zofia , Niemiec Dominik , Neuman David , Mońka Jakub , Dąbrowska Jolanta
Published: October 2021

The aim of the article is to compare two classifications systems of engineering-geological environment sustainability in terms of its permeability evaluated on the basis of permeability coefficient. The first evaluated classification assumes a permeable environment to be a positive characteristic in the engineering-geological assessment, while the other considers an impermeable environment as favourable. The four fine-grained soil materials were selected, as they had very similar, almost identical grains-size distribution, but different microstructure characterized by grains sphericity, angularity, and roughness. At the same time, the influence of changes in the density of soil materials (density index 10%, 30%, 60%, 90%) was analysed. Permeability coefficient was determined using six methods (empirical formulae, laboratory and microscopic analysis). The laboratory method falling head test (FHT) was taken as a reference test that reflected the actual water flow through the soil. It was found that with an increase in grain angularity and roughness (and a decrease in sphericity), the permeability coefficient was decreasing and this trend culminated along with gradual compaction. Moreover, the research shows that unsuitable methods may classify soil materials into wrong engineering-geological permeability classes, which may have negative consequences during engineering-geological or geotechnical assessment and cause subsequent problems in foundation engineering.
Temperature Influence on Additive Manufactured Carbon Fiber Reinforced Polymer Composites
Authors: Muna Isyna Izzal , Mieloszyk Magdalena
Published: October 2021

The popular applications of Additive Manufactured (AM) polymer materials in engineering, medical, and industrial fields have been widely recognized due to their high-speed production despite their complex design shapes. Fused Deposition Modeling (FDM) is the technique that has become the most renowned AM process due to its simplicity and because it is the cheapest method. The main objective of this research is to perform a numerical simulation of the thermo-mechanical behaviour of AM polymer with continuous carbon fibre reinforcement exposed to elevated temperatures. The influence of global thermal loads on AM material was focused on mechanical property changes at the microscale (level of fiber–matrix interaction). The mechanical response (strain/stress distribution) of the AM material on the temperature loading was modelled using the finite element method (FEM). The coupled thermal-displacement analysis was used during the numerical calculations. The strain in the sample due to its exposition on elevated temperature was measured using fibre Bragg grating (FBG) sensors. The numerical results were compared with the experimental results achieved for the sample exposure to the same thermal conditions showing good agreement. A strong influence of the temperature on the matrix structure and the condition of bondings between fibres and matrix was observed.
The Properties of Lightweight Aggregates Pre-Coated with Cement Pastes and Their Suitability for Concrete
Authors: Domagała Lucyna , Bryła Ewa
Published: October 2021

One of the biggest technological problems connected with the production of lightweight concretes made of porous aggregates is their much higher water absorption, which may cause on the one hand workability loss, and on the other hand excess water content in concrete. The aim of this research was to assess the effect of impregnation of lightweight aggregates (LWAs) with cement paste on their properties and to verify its effectiveness in concretes. Three types of lightweight aggregates differing in porosity and pore structure (sintered fly ash Lytag, expanded clay: Leca and Liapor) were selected for the tests. The following parameters were taken into consideration in the research program: LWA type and size, LWA initial moisture content, strength, and rheology of cement pastes. The tests of 22 different aggregates, plain and coated with cement paste, included density, crushing strength, and development of water absorption in time. The research program proved that porous aggregates, due to their impregnation with cement pastes, may be effectively sealed and strengthened. All tested LWAs showed a considerable decrease in water absorption by up to 71%. However, only Lytag aggregate showed a visibly enhanced crushing strength. Verification of effectiveness of aggregate sealing on the enhancement of concrete properties showed both a considerable reduction in water absorption of composites (by up to 52%) and a very high increase in their strength (by up to 107%).
Development of Low-Shrink Epoxy Putty to Solve Appearance-Quality Defects of Carbon-Fiber-Reinforced Plastic Automotive Exterior Parts
Authors: Yoon Manseok , Yoo Kwangsik , Seo Bongkuk , Ko Seung Hwan , Lim Choong-Sun
Published: October 2021

In this study, epoxy putties with novel compositions were developed for the filling of structural voids in carbon-fiber-reinforced plastics (CFRPs), which are used to fabricate automotive parts. Two constituent solutions—one consisting of epoxy resins and the other consisting of a hardener—were formulated, mixed, and then coated on CFRP surfaces, followed by curing. The surfaces were then evaluated to determine the shrinkage rates (calculated based on the liquid densities and cured mixtures), adhesion properties (determined by a peel test), and color differences (measured with a colorimeter) of the synthesized putties. The last two properties were compared with those of the commercially available putties to ascertain the thermal resistance of the developed putties. The results indicated that the synthesized epoxy putties were more strongly adhesive and exhibited less difference in color. Furthermore, after thermal impact, both the adhesive properties and color stabilities of the synthesized epoxy putties were found to be superior to those of the commercial putty.
Evaluation of the Antitumour and Antiproliferative Effect of Xanthohumol-Loaded PLGA Nanoparticles on Melanoma
Authors: Fonseca Magda , Macedo Ana S. , Lima Sofia A. Costa , Reis Salette , Soares Raquel , Fonte Pedro
Published: October 2021

Cutaneous melanoma is the deadliest type of skin cancer and current treatment is still inadequate, with low patient survival rates. The polyphenol xanthohumol has been shown to inhibit tumourigenesis and metastasization, however its physicochemical properties restrict its application. In this work, we developed PLGA nanoparticles encapsulating xanthohumol and tested its antiproliferative, antitumour, and migration effect on B16F10, malignant cutaneous melanoma, and RAW 264.7, macrophagic, mouse cell lines. PLGA nanoparticles had a size of 312 ± 41 nm and a PdI of 0.259, while achieving a xanthohumol loading of about 90%. The viability study showed similar cytoxicity between the xanthohumol and xanthohumol-loaded PLGA nanoparticles at 48 h with the IC50 established at 10 µM. Similar antimigration effects were observed for free and the encapsulated xanthohumol. It was also observed that the M1 antitumor phenotype was stimulated on macrophages. The ultimate anti-melanoma effect emerges from an association between the viability, migration and macrophagic phenotype modulation. These results display the remarkable antitumour effect of the xanthohumol-loaded PLGA nanoparticles and are the first advance towards the application of a nanoformulation to deliver xanthohumol to reduce adverse effects by currently employed chemotherapeutics.
The Designation Degree of Tool Wear after Machining of the Surface Layer of Duplex Stainless Steel
Authors: Dyl Tomasz
Published: October 2021

This paper presents problems related to the machining of the surface layer. It is important that steel structures are used in material engineering and machine construction. Austenitic, ferritic, martensitic and two-phase corrosion resistant steel was widely used in the petrochemical and shipbuilding industries. Duplex stainless steel was used in sea water and acid installations. The shafts of centrifugal pumps can be made of stainless steel and are used in acid or seawater pumps. The surface layer of corrosion resistant steel shafts must have a low surface roughness. Machine elements made of stainless steel, and in particular of the duplex type, are difficult-to-cut materials. This article aims to study the effect of parameters on tool life and tool wear. The influence of technological parameters such as depth of cut, cutting speed, feed on maximum value tool wear is presented. The treatment of the surface layer was performed using carbide inserts. The highest wear and the lowest roughness were used as selection criteria. This problem is a significant issue due to the ability of the machine parts for the required reliable operation of devices and machines. To determine the degree of tool wear to increase of the surface layer quality after shaping DSS.
Wound Healing Metabolites from Peters’ Elephant-Nose Fish Oil: An In Vivo Investigation Supported by In Vitro and In Silico Studies
Authors: Alsenani Faisal , Ashour Ahmed M. , Alzubaidi Mubarak A. , Azmy Ahmed F. , Hetta Mona H. , Abu-Baih Dalia H. , Elrehany Mahmoud A. , Zayed Ahmed , Sayed Ahmed M. , Abdelmohsen Usama Ramadan , Elmaidomy Abeer H.
Published: October 2021

Gnathonemuspetersii (F. Mormyridae) commonly known as Peters’ elephant-nose fish is a freshwater elephant fish native to West and Central African rivers. The present research aimed at metabolic profiling of its derived crude oil via GC-MS analysis. In addition, wound healing aptitude in adult male New Zealand Dutch strain albino rabbits along with isolated bioactive compounds in comparison with a commercial product (Mebo®). The molecular mechanism was studied through a number of in vitro investigations, i.e., radical scavenging and inhibition of COX enzymes, in addition to in silico molecular docking study. The results revealed a total of 35 identified (71.11%) compounds in the fish oil, belonging to fatty acids (59.57%), sterols (6.11%), and alkanes (5.43%). Phytochemical investigation of the crude oil afforded isolation of six compounds 1–6. Moreover, the crude oil showed significant in vitro hydrogen peroxide and superoxide radical scavenging activities. Furthermore, the crude oil along with one of its major components (compound 4) exhibited selective inhibitory activity towards COX-2 with IC50 values of 15.27 and 2.41 µM, respectively. Topical application of the crude oil on excision wounds showed a significant (p < 0.05) increase in the wound healing rate in comparison to the untreated and Mebo®-treated groups, where fish oil increased the TGF-β1 expression, down-regulated TNF-α, and IL-1β. Accordingly, Peters’ elephant-nose fish oil may be a potential alternative medication helping wound healing owing to its antioxidant and anti-inflammatory activities.
Physical Agent Modalities in Early Osteoarthritis: A Scoping Review
Authors: Letizia Mauro Giulia , Scaturro Dalila , Gimigliano Francesca , Paoletta Marco , Liguori Sara , Toro Giuseppe , Iolascon Giovanni , Moretti Antimo
Published: October 2021

Early osteoarthritis (EOA) still represents a challenge for clinicians. Although there is no consensus on its definition and diagnosis, a prompt therapeutic intervention in the early stages can have a significant impact on function and quality of life. Exercise remains a core treatment for EOA; however, several physical modalities are commonly used in this population. The purpose of this paper is to investigate the role of physical agents in the treatment of EOA. A technical expert panel (TEP) of 8 medical specialists with expertise in physical agent modalities and musculoskeletal conditions performed the review following the PRISMA-ScR (Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews) model. The TEP searched for evidence of the following physical modalities in the management of EOA: “Electric Stimulation Therapy”, “Pulsed Electromagnetic field”, “Low-Level Light Therapy”, “Laser Therapy”, “Magnetic Field Therapy”, “Extracorporeal Shockwave Therapy”, “Hyperthermia, Induced”, “Cryotherapy”, “Vibration therapy”, “Whole Body Vibration”, “Physical Therapy Modalities”. We found preclinical and clinical data on transcutaneous electrical nerve stimulation (TENS), extracorporeal shockwave therapy (ESWT), low-intensity pulsed ultrasound (LIPUS), pulsed electromagnetic fields stimulation (PEMF), and whole-body vibration (WBV) for the treatment of knee EOA. We found two clinical studies about TENS and PEMF and six preclinical studies—three about ESWT, one about WBV, one about PEMF, and one about LIPUS. The preclinical studies demonstrated several biological effects on EOA of physical modalities, suggesting potential disease-modifying effects. However, this role should be better investigated in further clinical studies, considering the limited data on the use of these interventions for EOA patients.
Porosity Prediction of Porous Materials Deposited by Semi-Molten Spraying Particles
Authors: Yao Jian-Tao , Dong Hui , Wang Li-Shuang
Published: October 2021

To determine the relationship between the deposition characteristics of semi-molten particles and the porosity of porous materials prepared by flame spraying, metal powders of Mo and 316L were used and the melting degree of deposition particles was controlled. Based on the experimental observations, a three-dimensional, random-stacking model was established by introducing the slipping characteristics of semi-molten particles, which could help predict the porosity of the generated porous metal materials. The results show that the maximum porosity of porous materials deposited by semi-molten particles was about 82%. A one-to-one relationship was observed between the melting degree of particles and the porosity of deposited samples. The three-dimensional random model could successfully predict the porosity of porous materials by combining the melting degree and slipping characteristics of spray particles, and the predicted values were consistent with the experimental results. The results of this study are useful to control the pore structure of porous materials deposited by semi-molten spraying particles.
“Maybe Jesus Was Suicidal Too”: A United Church of Christ Pastor Reflects on His Suicide Attempt
Authors: Hall Elizabeth Ryan
Published: October 2021

Research has long demonstrated that people who are religiously involved tend to be more shielded from suicide than those who are not, yet it has been less attentive to the conditions under which religiosity fails to inhibit suicidality. Since Durkheim’s 1897 Suicide investigated the link between religious affiliation and suicide rates, most of the related research has also taken a broadscale sociological approach, used simplistic measures of religiosity, and ignored spirituality. Virtually absent are more penetrating idiographic investigations into suicidal individuals’ lived experiences of religion and spirituality. This article aims to rectify that by presenting a qualitative study of eight suicide attempt survivors in the US. The complex convergences of religion/spirituality and suicidality in their lives are discussed. Religion and spirituality did palliate the participants’ suicidality, but only after their suicide attempts; prior to the attempts, religious factors aggravated and even induced suicidal urges. During the suicide attempts, meanwhile, religion and spirituality were inconsequential. The story of one participant, an ordained minister in the United Church of Christ, is highlighted to illustrate the findings. Recommendations for further research and suggestions for spiritually integrated approaches to care encounters with suicidal individuals are given.
A Robust Observer-Based Control Strategy for n-DOF Uncertain Robot Manipulators with Fixed-Time Stability
Authors: Vo Anh Tuan , Truong Thanh Nguyen , Kang Hee-Jun , Van Mien
Published: October 2021

In this paper, a robust observer-based control strategy for n-DOF uncertain robot manipulators with fixed-time stability was developed. The novel fixed-time nonsingular sliding mode surface enables control errors to converge to the equilibrium point quickly within fixed time without singularity. The development of the novel fixed-time disturbance observer based on a uniform robust exact differentiator also allows uncertain terms and exterior disturbances to be proactively addressed. The designed observer can accurately approximate uncertain terms within a fixed time and contribute to significant chattering reduction in the traditional sliding mode control. A robust observer-based control strategy was formulated, according to a combination of the fixed-time nonsingular terminal sliding mode control method and the designed observer, to yield global fixed time stability for n-DOF uncertain robot manipulators. The proposed controller proved definitively that it was able to obtain global stabilization in fixed time. The approximation capability of the proposed observer, the convergence of the proposed sliding surface, and the effectiveness of the proposed control strategy in fixed time were fully confirmed by simulation performance on an industrial robot manipulator.
Regression Based Iterative Illumination Compensation Method for Multi-Focal Whole Slide Imaging System
Authors: Paulik Róbert , Kozlovszky Miklós , Molnár Béla
Published: October 2021

Image quality, resolution and scanning time are critical in digital pathology. In order to create a high-resolution digital image, the scanner systems execute stitching algorithms to the digitized images. Due to the heterogeneity of the tissue sample, complex optical path, non-acceptable sample quality or rapid stage movement, the intensities on pictures can be uneven. The evincible and visible intensity distortions can have negative effect on diagnosis and quantitative analysis. Utilizing the common areas of the neighboring field-of-views, we can estimate compensations to eliminate the inhomogeneities. We implemented and validated five different approaches for compensating output images created with an area scanner system. The proposed methods are based on traditional methods such as adaptive histogram matching, regression-based corrections and state-of-the art methods like the background and shading correction (BaSiC) method. The proposed compensation methods are suitable for both brightfield and fluorescent images, and robust enough against dust, bubbles, and optical aberrations. The proposed methods are able to correct not only the fixed-pattern artefacts but the stochastic uneven illumination along the neighboring or above field-of-views utilizing iterative approaches and multi-focal compensations.
A Smooth Non-Iterative Local Polynomial (SNILP) Model of Image Vignetting
Authors: Bal Artur , Palus Henryk
Published: October 2021

Image vignetting is one of the major radiometric errors, which occurs in lens-camera systems. In many applications, vignetting is an undesirable phenomenon; therefore, when it is impossible to fully prevent its occurrence, it is necessary to use computational methods for its correction in the acquired image. In the most frequently used approach to the vignetting correction, i.e., the flat-field correction, the usage of appropriate vignetting models plays a crucial role. In the article, the new model of vignetting, i.e., Smooth Non-Iterative Local Polynomial (SNILP) model, is proposed. The SNILP model was compared with the models known from the literature, e.g., the polynomial 2D and radial polynomial models, in a series of numerical tests and in the real-data experiment. The obtained results prove that the SNILP model usually gives better vignetting correction results than the other aforementioned tested models. For images larger than UXGA format (1600×1200), the proposed model is also faster than other tested models. Moreover, among the tested models, the SNILP model requires the least hardware resources for its application. This means that the SNILP model is suitable for its usage in devices with limited computing power.
Enabling Context-Aware Data Analytics in Smart Environments: An Open Source Reference Implementation
Authors: Munoz-Arcentales Andres , López-Pernas Sonsoles , Conde Javier , Alonso Álvaro , Salvachúa Joaquín , Hierro Juan José
Published: October 2021

In recent years, many proposals of context-aware systems applied to IoT-based smart environments have been presented in the literature. Most previous works provide a generic high-level structure of how a context-aware system can be operationalized, but do not offer clues on how to implement it. On the other hand, there are many implementations of context-aware systems applied to specific IoT-based smart environments that are context-specific: it is not clear how they can be extended to other use cases. In this article, we aim to provide an open-source reference implementation for providing context-aware data analytics capabilities to IoT-based smart environments. We rely on the building blocks of the FIWARE ecosystem and the NGSI data standard, providing an agnostic end-to-end solution that considers the complete data lifecycle, covering from data acquisition and modeling, to data reasoning and dissemination. In other words, our reference implementation can be readily operationalized in any IoT-based smart environment regardless of its field of application, providing a context-aware solution that is not context-specific. Furthermore, we provide two example use cases that showcase how our reference implementation can be used in a variety of fields.
Lead-Free AE Sensor Based on BZT–BCT Ceramics
Authors: Shin Dong-Jin , Kang Woo-Seok , Lim Dong-Hwan , Koo Bo-Kun , Kim Min-Soo , Jeong Soon-Jong , Kim In-Sung
Published: October 2021

In this study, an acoustic emission (AE) sensor was fabricated using lead-free Ba(Zr0.2Ti0.8)O3–0.5(Ba0.7Ca0.3)TiO3 (BZT–BCT) ceramics. The acoustic and electromechanical properties of the AE sensor were determined by the shapes of the piezoelectric ceramics. To optimize the AE sensor performance, the shapes of the ceramics were designed according to various diameter/thickness ratios (D/T) = 0.5, 1.0, 1.5, 2.0, 2.5, 3.0. The BZT–BCT ceramic with D/T = 1.0 exhibited excellent values of a piezoelectric charge coefficient (d33), piezoelectric voltage coefficient (g33), and electromechanical coupling factor (kp), which were 370 (pC/N), 11.3 (10−3 Vm/N), and 0.58, respectively. Optimum values of resonant frequency (fr) = 172.724 (kHz), anti-resonant frequency (fa) = 196.067 (kHz), and effective electromechanical coupling factor (keff) = 0.473 were obtained for the manufactured BZT–BCT ceramic with D/T = 1.0. The maximum sensitivity and frequency of the AE sensor made of the BZT–BCT ceramic with a D/T ratio of 1.0 were 65 dB and 30 kHz, respectively.
Recent Advances on Functional Nucleic-Acid Biosensors
Authors: Yu Xinhong , Zhang Shiqi , Guo Wenqiang , Li Boxi , Yang Yang , Xie Bingqing , Li Ke , Zhang Li
Published: October 2021

In the past few decades, biosensors have been gradually developed for the rapid detection and monitoring of human diseases. Recently, functional nucleic-acid (FNA) biosensors have attracted the attention of scholars due to a series of advantages such as high stability and strong specificity, as well as the significant progress they have made in terms of biomedical applications. However, there are few reports that systematically and comprehensively summarize its working principles, classification and application. In this review, we primarily introduce functional modes of biosensors that combine functional nucleic acids with different signal output modes. In addition, the mechanisms of action of several media of the FNA biosensor are introduced. Finally, the practical application and existing problems of FNA sensors are discussed, and the future development directions and application prospects of functional nucleic acid sensors are prospected.
Exponential-Distance Weights for Reducing Grid-like Artifacts in Patch-Based Medical Image Registration
Authors: Wu Liang , Hu Shunbo , Liu Changchun
Published: October 2021

Patch-based medical image registration has been well explored in recent decades. However, the patch fusion process can generate grid-like artifacts along the edge of patches for the following two reasons: firstly, in order to ensure the same size of input and output, zero-padding is used, which causes uncertainty in the edges of the output feature map during the feature extraction process; secondly, the sliding window extraction patch with different strides will result in different degrees of grid-like artifacts. In this paper, we propose an exponential-distance-weighted (EDW) method to remove grid-like artifacts. To consider the uncertainty of predictions near patch edges, we used an exponential function to convert the distance from the point in the overlapping regions to the center point of the patch into a weighting coefficient. This gave lower weights to areas near the patch edges, to decrease the uncertainty predictions. Finally, the dense displacement field was obtained by this EDW weighting method. We used the OASIS-3 dataset to evaluate the performance of our method. The experimental results show that the proposed EDW patch fusion method removed grid-like artifacts and improved the dice similarity coefficient superior to those of several state-of-the-art methods. The proposed fusion method can be used together with any patch-based registration model.
Desafíos del comercio electrónico para las PYMES ecuatorianas
Authors: Mera Carlos
Published: October 2021

El presente trabajo de investigación, estudió los principales desafíos que enfrentan las PYMES ecuatorianas para adaptarse y competir en una economía digital, cuyo propósito, fue el de aportar con información que permitió exponer un conjunto de mecanismos que posibiliten su participación interactiva en línea. Para lograr este objetivo, el autor realizó una investigación descriptiva documental, mediante un enfoque cualitativo, utilizando como referencia de estudio, los procesos empresariales que se llevan a cabo en el Ecuador, relacionados a: (1) los sistemas de pago; (2) las plataformas digitales de comercio; y, (3) las operaciones logísticas, que según el Banco Interamericano de Desarrollo (en adelante BID), deben digitalizarse para que las PYMES puedan fortalecer su adopción del comercio electrónico.

Dentro de los principales resultados obtenidos, se encontraron que, un alto porcentaje de la población (49%) no está bancarizado, por lo tanto, no utilizan medios de pago electrónico; sobre las plataformas digitales, estos aún se encuentran en etapa de desarrollo para consolidarse como herramienta de las PYMES en un mercado competitivo; y, sobre las operaciones logísticas, se identificó que su aplicación debe estar orientado en la reducción de plazos de entrega, y en mejorar la comunicación con los clientes.

Los hallazgos encontrados, sugieren que la digitalización de estos procesos requiere, además de la implicación en la gestión de cambio de las PYMES ecuatorianas, del apoyo y participación de actores externos, tanto públicos, como privados, ya que estos pueden desempeñar un rol clave en la facilitación y desarrollo de una hoja de ruta, acorde a los recursos y necesidades de cada caso.