bluuebunny/crossref_metadata_2025 huggingface dataset:
Development of a Natural Matrix Hybrid Hydrogel Patch and Evaluation of Its Efficacy against Atopic Dermatitis
Authors: Hong Gyeong Sik , Choi Jeong Yeon , Suh Jang Soo , Lim Jeong Ok , Choi Jin Hyun
Published: December 2020

Although there is no cure for atopic dermatitis (AD), treatments to relieve AD symptoms are available. A previously developed topical patch for AD treatment minimizes skin irritation but does not sufficiently adhere and absorb to specific areas. Centella asiatica extract (CAE) is a natural polymer for atopic treatment. This study fabricated a CAE-loaded hyaluronic acid-dextran (HA-Dex) hybrid hydrogel patch for use as an AD treatment and evaluated the effect of varying CAE concentrations in the patch. The CAE-loaded HA-Dex hybrid hydrogel patch was fabricated into a sheet-type scaffold using a freeze-drying process and 1,4-butanediol diglycidyl ether (BDDE). Fibroblasts (L929 cells) were used to evaluate cell survival, and physical properties were evaluated using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, a universal testing machine, and high-performance liquid chromatography. A 0.4 wt% CAE-loaded HA-Dex hybrid hydrogel patch produced the most stable release profile and the highest level of cellular activity. These hydrogel patches provided moisture and released CAE over an extended period of time, making them ideal for relieving atopic itching. This delivery system enables the extended release of CAE to localized areas and could potentially be used to apply a variety of products to treat AD.
Examination of WRF-ARW Experiments Using Different Planetary Boundary Layer Parameterizations to Study the Rapid Intensification and Trajectory of Hurricane Otto (2016)
Authors: Maldonado Tito , Amador Jorge A. , Rivera Erick R. , Hidalgo Hugo G. , Alfaro Eric J.
Published: December 2020

Hurricane Otto (2016) was characterised by remarkable meteorological features of relevance for the scientific community and society. Scientifically, among the most important attributes of Otto is that it underwent a rapid intensification (RI) process. For society, this cyclone severely impacted Costa Rica and Nicaragua, leaving enormous economic losses and many fatalities. In this study, a set of three numerical simulations are performed to examine the skill of model estimations in reproducing RI and trajectory of Hurricane Otto by comparing the results of a global model to a regional model using three different planetary boundary layer parameterizations (PBL). The objective is to set the basis for future studies that analyse the physical reasons why a particular simulation (associated with a certain model setup) performs better than others in terms of reproducing RI and trajectory. We use the regional model Weather Research and Forecasting—Advanced Research WRF (WRF-ARW) with boundary and initial conditions provided by the Global Forecast System (GFS) analysis (horizontal resolution of 0.5 degrees). The PBL used are the Medium Range Forecast, the Mellor-Yamada-Janjic (MYJ), and the Yonsei University (YSU) parameterizations. The regional model is run in three static domains with horizontal grid spacing of 27, 9 and 3 km, the latter covering the spacial extent of Otto during the simulation period. WRF-ARW results improve the GFS forecast, in almost every aspect evaluated in this study, particularly, the simulated trajectories in WRF-ARW show a better representation of the cyclone path and movement compared to GFS. Even though the MYJ experiment was the only one that exhibited an abrupt 24-h change in the storm’s surface wind, close to the 25-knot threshold, the YSU scheme presented the fastest intensification, closest to reality.
Seeking the Sources of Dust: Geochemical and Magnetic Studies on “Cryodust” in Glacial Cores from Southern Spitsbergen (Svalbard, Norway)
Authors: Lewandowski Marek , Kusiak Monika A. , Werner Tomasz , Nawrot Adam , Barzycka Barbara , Laska Michał , Luks Bartłomiej
Published: December 2020

Natural mineral particulate matter deposited from aerosols and trapped in glaciers—herein defined as “cryodust”—may be an excellent indicator of atmospheric circulation, if terrestrial sources of dust can be identified. In this study, we analyzed the composition of cryodust in shallow ice cores taken from five glaciers in Southern Spitsbergen (Svalbard Archipelago, Northern Norway). The chemical composition, magnetic properties and radiogenic ages of individual grains were measured, where possible, to provide indicators of source areas. To identify mineral and rock fragments, solid particulates were examined by Scanning Electron Microscope fitted with a backscattered electron and Energy Dispersive Spectroscopic detectors. An Electron MicroProbe was employed for the U-Th-Pb chemical dating of monazite grains. Magnetic measurements comprised analyses of magnetic susceptibility (κ) vs. temperature (T) variations and determination of magnetic hysteresis parameters. Monazite ages span 445–423 Ma, consistent with mineral growth during the Caledonian orogeny. Caledonian rocks are exposed in the Nordaustlandet area of North-Eastern Svalbard, and this is the most probable source for monazite grains. Magnetic analyses show a predominance of ferrous (FeII) over ferric (FeIII) phases, consistent with a lack of input from subtropical sources. The results from both methods are consistent with local sources of dust from exposures in the Svalbard archipelago.
Indoor Air Pollution from Residential Stoves: Examining the Flooding of Particulate Matter into Homes during Real-World Use
Authors: Chakraborty Rohit , Heydon James , Mayfield Martin , Mihaylova Lyudmila
Published: December 2020

This study concerns the levels of particulate matter (PM2.5 and PM1) released by residential stoves inside the home during ‘real world’ use. Focusing on stoves that were certified by the UK’s Department of Environment, Food, and Rural Affairs (DEFRA), PM sensors were placed in the vicinity of 20 different stoves over four weeks, recording 260 uses. The participants completed a research diary in order to provide information on time lit, amount and type of fuel used, and duration of use, among other details. Multivariate statistical tools were used in order to analyse indoor PM concentrations, averages, intensities, and their relationship to aspects of stove management. The study has four core findings. First, the daily average indoor PM concentrations when a stove was used were higher for PM2.5 by 196.23% and PM1 by 227.80% than those of the non-use control group. Second, hourly peak averages are higher for PM2.5 by 123.91% and for PM1 by 133.09% than daily averages, showing that PM is ‘flooding’ into indoor areas through normal use. Third, the peaks that are derived from these ’flooding’ incidents are associated with the number of fuel pieces used and length of the burn period. This points to the opening of the stove door as a primary mechanism for introducing PM into the home. Finally, it demonstrates that the indoor air pollution being witnessed is not originating from outside the home. Taken together, the study demonstrates that people inside homes with a residential stove are at risk of exposure to high intensities of PM2.5 and PM1 within a short period of time through normal use. It is recommended that this risk be reflected in the testing and regulation of residential stoves.
Socioeconomic Reinvention and Expanding Engagement with Climate Change Policy in American Rust Belt Cities
Authors: Kalafatis Scott E.
Published: December 2020

Despite an appreciation for the role of cities in addressing global climate change, more studies are needed that explore how climate change policies relate to cities’ everyday governing concerns. Such insights are critical for understanding how climate change policy will expand, play out, and evolve as it moves from experimental efforts in particularly innovative cities to the majority of cities. This study addresses these needs using 32 interviews and over 200 survey responses from smaller cities (populations under 100,000) in the American rust belt. In the interviews comparing cities’ financial concerns, economic development considerations, and how other cities influence them, a distinctive mindset amongst cities highly engaged with climate change emerged. Highly engaged cities were those pursuing socioeconomic reinvention, informed by efforts to identify and apply policy ideas from a wide range of other cities across the United States and internationally. Results of the regression analyses supported the notion that financial concerns, economic development considerations, and the influence of other cities shape decisions about climate change policy in these cities. However, they also highlighted the complexity of these issues and that the role these factors had in shaping climate change policy will likely continue to evolve as these policies continue to diffuse to more places.
Increased Prevalence of Face Mask—Induced Itch in Health Care Workers
Authors: Krajewski Piotr K. , Matusiak Łukasz , Szepietowska Marta , Białynicki-Birula Rafał , Szepietowski Jacek C.
Published: December 2020

Background: Face mask use has increased significantly due to the COVID-19 pandemic. Health care workers (HCW) wear masks for prolonged periods and are prone to adverse effects. Very little is known about face-mask-associated itch. Methods: This Internet survey study investigated the prevalence, intensity and clinical characteristics of itch related to the use of face masks by HCW during the COVID-19 pandemic. The results were subsequently compared to the students’ group. Results: A total of 1156 HCW completed the survey. Among them, 31.6% (365) reported suffering from itch associated with face mask use. Itch was more frequent among females. Moreover, subjects who reported sensitive skin, atopic predispositions and facial dermatoses tended to report itch more frequently. The worst case of itch in the seven days prior to the study, assessed with the numeric rating scale (NRS), was 4.6 ± 2.0 points. Itch prevalence increased along with the duration of face mask use, being 34.6% among those who wore masks for more than 4 h. HCW reported itch significantly more frequently than students. Conclusions: Face-mask-associated itch is a frequent problem among HCW in the COVID-19 pandemic. Itch sensation may cause scratching, which may decrease necessary protection during the pandemic.
Experimental Study on Blue Light Interaction with Human Keloid-Derived Fibroblasts
Authors: Magni Giada , Banchelli Martina , Cherchi Federica , Coppi Elisabetta , Fraccalvieri Marco , Rossi Michele , Tatini Francesca , Pugliese Anna Maria , Rossi Degl’Innocenti Duccio , Alfieri Domenico , Matteini Paolo , Pini Roberto , Pavone Francesco S. , Rossi Francesca
Published: December 2020

Keloids are an exuberant response to wound healing, characterized by an exaggerated synthesis of collagen, probably due to the increase of fibroblasts activity and to the reduction of their apoptosis rate: currently no standard treatments or pharmacological therapies are able to prevent keloid recurrence. To reach this goal, in recent years some physical treatments have been proposed, and among them the PhotoBioModulation therapy (PBM). This work analyses the effects of a blue LED light irradiation (410–430 nm, 0.69 W/cm2 power density) on human fibroblasts, isolated from both keloids and perilesional tissues. Different light doses (3.43–6.87–13.7–20.6–30.9 and 41.2 J/cm2) were tested. Biochemical assays and specific staining were used to assess cell metabolism, proliferation and viability. Micro-Raman spectroscopy was used to explore direct effects of the blue LED light on the Cytochrome C (Cyt C) oxidase. We also investigated the effects of the irradiation on ionic membrane currents by patch-clamp recordings. Our results showed that the blue LED light can modulate cell metabolism and proliferation, with a dose-dependent behavior and that these effects persist at least till 48 h after treatment. Furthermore, we demonstrated that the highest fluence value can reduce cell viability 24 h after irradiation in keloid-derived fibroblasts, while the same effect is observed 48 h after treatment in perilesional fibroblasts. Electrophysiological recordings showed that the medium dose (20.6 J/cm2) of blue LED light induces an enhancement of voltage-dependent outward currents elicited by a depolarizing ramp protocol. Overall, these data demonstrate the potentials that PBM shows as an innovative and minimally-invasive approach in the management of hypertrophic scars and keloids, in association with current treatments.
Mutations and Copy Number Alterations in IDH Wild-Type Glioblastomas Are Shaped by Different Oncogenic Mechanisms
Authors: Ülgen Ege , Karacan Sıla , Gerlevik Umut , Can Özge , Bilguvar Kaya , Oktay Yavuz , B. Akyerli Cemaliye , K. Yüksel Şirin , E. Danyeli Ayça , Tihan Tarık , Sezerman O. Uğur , Yakıcıer M. Cengiz , Pamir M. Necmettin , Özduman Koray
Published: December 2020

Little is known about the mutational processes that shape the genetic landscape of gliomas. Numerous mutational processes leave marks on the genome in the form of mutations, copy number alterations, rearrangements or their combinations. To explore gliomagenesis, we hypothesized that gliomas with different underlying oncogenic mechanisms would have differences in the burden of various forms of these genomic alterations. This was an analysis on adult diffuse gliomas, but IDH-mutant gliomas as well as diffuse midline gliomas H3-K27M were excluded to search for the possible presence of new entities among the very heterogenous group of IDH-WT glioblastomas. The cohort was divided into two molecular subsets: (1) Molecularly-defined GBM (mGBM) as those that carried molecular features of glioblastomas (including TERT promoter mutations, 7/10 pattern, or EGFR-amplification), and (2) those who did not (others). Whole exome sequencing was performed for 37 primary tumors and matched blood samples as well as 8 recurrences. Single nucleotide variations (SNV), short insertion or deletions (indels) and copy number alterations (CNA) were quantified using 5 quantitative metrics (SNV burden, indel burden, copy number alteration frequency-wGII, chromosomal arm event ratio-CAER, copy number amplitude) as well as 4 parameters that explored underlying oncogenic mechanisms (chromothripsis, double minutes, microsatellite instability and mutational signatures). Findings were validated in the TCGA pan-glioma cohort. mGBM and “Others” differed significantly in their SNV (only in the TCGA cohort) and CNA metrics but not indel burden. SNV burden increased with increasing age at diagnosis and at recurrences and was driven by mismatch repair deficiency. On the contrary, indel and CNA metrics remained stable over increasing age at diagnosis and with recurrences. Copy number alteration frequency (wGII) correlated significantly with chromothripsis while CAER and CN amplitude correlated significantly with the presence of double minutes, suggesting separate underlying mechanisms for different forms of CNA.
Biomarkers in Hepatocellular Carcinoma: Current Status and Future Perspectives
Authors: Pan Yasi , Chen Huarong , Yu Jun
Published: December 2020

Hepatocellular carcinoma (HCC) is the most common primary liver cancer and one of the leading causes of cancer-related death worldwide. HCC is highly heterogeneous, both within the tumor and among individuals, which is closely related to the HCC surveillance, diagnosis, prognosis, and treatment response. With the advances of next-generation sequencing, the genomic landscape of HCC has been identified which vastly improves our understanding of genetic and epigenetic changes and their interaction during HCC development. In particular, gene mutations, epigenetic modifications, aberrant expression of coding and non-coding RNAs have been extensively explored and many of them are considered as biomarkers for HCC. Most recently, the gut microbiome has been proposed as potential non-invasive biomarkers for HCC diagnosis. In this review, we summarize the current development of HCC biomarkers studies and provide insights on further steps towards precision medicine of HCC.
Anti-HER2/neu Antibody Reduces Chemotherapy-Induced Ovarian Toxicity—From Bench to Bedside
Authors: Levi Mattan , Goshen-Lago Tal , Yerushalmi Rinat , Granot Tal , Stemmer Salomon M. , Shalgi Ruth , Ben-Aharon Irit
Published: December 2020

Background: Trastuzumab, a humanized anti-human epidermal growth factor receptor 2 (HER2/neu) antibody, is considered a standard treatment in addition to chemotherapy in the adjuvant setting for HER2/neu-positive breast cancer, yet its impact on fertility and ovarian reserve remains obscure. We aimed to study the effect of anti-HER2/neu on chemotherapy-induced ovarian toxicity in both clinical and preclinical settings. Methods: We prospectively enrolled breast cancer patients below the age of 42 years who were treated with chemotherapy with or without trastuzumab into the study. Anti-Müllerian hormone (AMH) was measured 6 and 12 months post-chemotherapy as an ovarian reserve indicator. In the animal model, pubertal mice were injected with cyclophosphamide or paclitaxel with or without anti-HER2/neu, or saline, and sacrificed 1 week or 3 months later. Ovarian apoptosis, proliferation and vascularity were measured by immunohistochemistry and ovarian reserve was measured by morphometric analysis and serum-AMH. Results: Thirty-three patients with early breast cancer were enrolled into the study. Nineteen patients had HER2/neu negative cancer and were treated with chemotherapy and 14 had HER2/neu positive cancer and were treated with chemotherapy and trastuzumab. In all patients, AMH levels declined to undetectable values immediately post-treatment, but regained for 57.1% of the HER2/neu positive cohort and 36.8% of the negative cohort (p < 0.05). In the preclinical setting, anti-HER2/neu antibody, in combination with chemotherapy, displayed lessened ovarian and vascular damage. Conclusions: Our results indicate that trastuzumab may alleviate chemotherapy-induced ovarian toxicity that may be mediated via its effect on ovarian vasculature.
Preserved Contextual Cueing in Realistic Scenes in Patients with Age-Related Macular Degeneration
Authors: Pollmann Stefan , Rosenblum Lisa , Linnhoff Stefanie , Porracin Eleonora , Geringswald Franziska , Herbik Anne , Renner Katja , Hoffmann Michael B.
Published: December 2020

Foveal vision loss has been shown to reduce efficient visual search guidance due to contextual cueing by incidentally learned contexts. However, previous studies used artificial (T- among L-shape) search paradigms that prevent the memorization of a target in a semantically meaningful scene. Here, we investigated contextual cueing in real-life scenes that allow explicit memory of target locations in semantically rich scenes. In contrast to the contextual cueing deficits in artificial scenes, contextual cueing in patients with age-related macular degeneration (AMD) did not differ from age-matched normal-sighted controls. We discuss this in the context of visuospatial working-memory demands for which both eye movement control in the presence of central vision loss and memory-guided search may compete. Memory-guided search in semantically rich scenes may depend less on visuospatial working memory than search in abstract displays, potentially explaining intact contextual cueing in the former but not the latter. In a practical sense, our findings may indicate that patients with AMD are less deficient than expected after previous lab experiments. This shows the usefulness of realistic stimuli in experimental clinical research.
Influence of Mothers’ Habits on Reading Skills and Emotional Intelligence of University Students: Relationships in the Social and Educational Context
Authors: Jiménez-Pérez Elena , Barrientos-Báez Almudena , Caldevilla-Domínguez David , Gómez-Galán José
Published: December 2020

Numerous studies show that the family plays a crucial role not only in the education of children but also in the acquisition of skills in the process of teaching and formal learning, especially in their reading competence. Furthermore, within the family, studies point to the basic role of the mother as the main axis of both educational and social teaching. The approach of this research aims to analyze whether maternal habits can influence the reading competence of their children. On the other hand, numerous studies point to the relationship between reading skills and emotional intelligence. Its inclusion in the equation of this construct can give information that will nuance the learning process in this evolutionary process. Thus, in this research, the objective is to establish the existence of a relationship between maternal reading habits with respect to reading competence and emotional intelligence in post-adolescents. Four-hundred-twenty first-year university students participated between the ages of 18 and 20 (43.8% men and 56.2% women) from the Andalusian universities of Granada, Malaga, and Jaen, all of them located in areas of medium socio-cultural context. Moderate mediation and factorial ANCOVA analyses have been carried out. The results point to the fact that the profile of the post-adolescents with the best score in reading competence also scores better in emotional intelligence and their mothers are those who score highest in reading habits. Thus, the role of the mother within the family is even more important than it appears in a society that seeks parity. New forms of work–family conciliation are necessary in order not to break the mother–child bond.
Electrochemical Evaluation of Laccase Activity in Must
Authors: Gáspár Szilveszter , Brinduse Elena , Vasilescu Alina
Published: December 2020

As laccase (produced by Botrytis cinerea) can significantly alter the properties of wine, winemakers frequently use commercially available colorimetric kits and spectrophotometers to measure the activity of this enzyme in grapes, must and wine. Although the used kits are based on electrochemically active substrates (such as syringaldazine and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid), ABTS), the electrochemical determination of laccase activity as an alternative to the colorimetric determination was not thoroughly investigated up to now. Therefore, in the present work, we explored the electrochemical determination of laccase activity. Laccase activity measurements were carried out using either carbon fiber microelectrodes or screen-printed electrodes as working electrodes, either syringaldazine or ABTS as the electrochemically active laccase substrate, and either cyclic voltammetry or constant potential amperometry as the electrochemical method. The best performing approach, which combines ABTS, screen-printed gold electrodes, and constant potential amperometry, allowed identifying laccase positive must sample (i.e., must samples with › 3U/mL laccase) in about 5 min.
Agro Waste Sugarcane Bagasse as a Cementitious Material for Reactive Powder Concrete
Authors: Sebastin Selvadurai , Priya Arun Kumar , Karthick Alagar , Sathyamurthy Ravishankar , Ghosh Aritra
Published: December 2020

In the field of advanced concrete science, the construction industry has risen to great heights. Due to its own characterisation, the manufacturing cost of reactive powder concrete (RPC) is very high. This can be minimised by substituting the components of the RPC with the aid of agro waste. Because of the production of sugar from the sugar cane industry, bagasse ash is abundantly available in India. It is not ideal for the direct replacement of ingredients in concrete because of the presence of carbon dioxide in bagasse ash. The study of bagasse ash’s actions under different temperatures and different exposure times is discussed in this paper. It is inferred from the findings obtained from the energy dispersive study of X-ray (EDAX) that the presence of reactive silica in bagasse ash could be substituted by RPC ingredients due to heat treatment. RPC is composed of exceptionally fine powders (cement, sand, quartz powder and silica smolder) and superplasticiser. The superplasticiser, utilised at its ideal dose, decreases the water to cement proportion (w/c) while enhancing the workability of the concrete. A thick matrix is accomplished by optimising the granular packing of the dry fine powders. This compactness gives RPC ultra-high quality and durability. Reactive powder concretes have compressive qualities extending from 200 to 800 MPa.
The Bioactive Polypyrrole/Polydopamine Nanowire Coating with Enhanced Osteogenic Differentiation Ability with Electrical Stimulation
Authors: He Yuan , Dai Lingfeng , Zhang Xiuming , Sun Yanan , Shi Wei , Ge Dongtao
Published: December 2020

Polypyrrole (PPy) is a promising conducting polymer in bone regeneration; however, due to the biological inertia of the PPy surface, it has poor cell affinity and bioactivity. Based on the excellent adhesion capacity, biocompatibility, and bioactivity of polydopamine (PDA), the PDA is used as a functional coating in tissue repair and regeneration. Herein, we used a two-step method to construct a functional conductive coating of polypyrrole/polydopamine (PPy/PDA) nanocomposite for bone regeneration. PPy nanowires (NWs) are used as the morphologic support layer, and a layer of highly bioactive PDA is introduced on the surface of PPy NWs by solution oxidation. By controlling the depositing time of PDA within 5 h, the damage of nano morphology and conductivity of the PPy NWs caused by the coverage of PDA deposition layer can be effectively avoided, and the thin PDA layer also significantly improve the hydrophilicity, adhesion, and biological activity of PPy NWs coating. The PPy/PDA NWs coating performs better biocombaitibility and bioactivity than pure PPy NWs and PDA, and has benefits for the adhesion, proliferation, and osteogenic differentiation of MC3T3-E1 cells cultured on the surface. In addition, PPy/PDA NWs can significantly promote the osteogenesis of MC3T3-E1 in combination with micro galvanostatic electrical stimulation (ES).
Equilibrium Orientation and Adsorption of an Ellipsoidal Janus Particle at a Fluid–Fluid Interface
Authors: Günther Florian , Xie Qingguang , Harting Jens
Published: December 2020

We investigate the equilibrium orientation and adsorption process of a single, ellipsoidal Janus particle at a fluid–fluid interface. The particle surface comprises equally sized parts that are hydrophobic or hydrophilic. We present free energy models to predict the equilibrium orientation and compare the theoretical predictions with lattice Boltzmann simulations. We find that the deformation of the fluid interface strongly influences the equilibrium orientation of the Janus ellipsoid. The adsorption process of the Janus ellipsoid can lead to different final orientations determined by the interplay of particle aspect ratio and particle wettablity contrast.
Fluorescent Labeling of Hyaluronic Acid-Chitosan Nanocarriers by Protein-Stabilized Gold Nanoclusters
Authors: Turcsányi Árpád , Ungor Ditta , Csapó Edit
Published: December 2020

In medical research the visualization of drug carrier accumulation and release of the loaded drugs in vivo is an important field. In this work, two protein-stabilized gold nanoclusters (Au NCs) as effective fluorescent reporters (FRs) were investigated for labeling of biocompatible chitosan-modified hyaluronic acid based nanocarriers having two different structures. The colloid stability of the labeled carriers was studied by dynamic light scattering and Zeta potential measurements, while the changes in the fluorescence of the lysozyme- (LYZ) and bovine serum albumin (BSA)-stabilized Au NCs were analyzed by spectrofluorimetry and confocal fluorescent microscopy. We found that the labeling was effective with a wide range of marker:carrier mass ratios, and the fluorescence of the NCs and the colloid stability of the complexes were retained. Labeling during preparation and subsequent labeling were compared, and based on composition (nanocluster:carrier mass ratio) and structure of the complex systems we preferred the latter method, as it left the Au NCs free for further modifications. Considering both marker:carrier mass ratios and emission intensities, the LYZ-stabilized Au NCs proved to be better labels. The core-shell type carrier formulations showed increased fluorescence with LYZ-stabilized NCs, presumably from aggregation induced emission.
Tensile Deformation of Ultrafine-Grained Fe-Mn-Al-Ni-C Alloy Studied by In Situ Synchrotron Radiation X-ray Diffraction
Authors: Gao Si , Yoshimura Takuma , Mao Wenqi , Bai Yu , Gong Wu , Park Myeong-heom , Shibata Akinobu , Adachi Hiroki , Sato Masugu , Tsuji Nobuhiro
Published: December 2020

Intermetallic compounds are usually considered as deleterious phase in alloy designing and processing since their brittleness leads to poor ductility and premature failure during deformation of the alloys. However, several studies recently found that some alloys containing large amounts of NiAl-type intermetallic particles exhibited not only high strength but also good tensile ductility. To clarify the role of the intermetallic particles in the excellent tensile properties of such alloys, the tensile deformation behavior of an ultrafine-grained Fe-Mn-Al-Ni-C alloy containing austenite matrix and B2 intermetallic particles was investigated by using in situ synchrotron radiation X-ray diffraction in the present study. The elastic stress partitioning behavior of two constituent phases during tensile deformation were quantitively measured, and it was suggested that B2 particles played an important role in the high strength and large tensile ductility of the material.
Epilithic Diatom Community Shows a Higher Vulnerability of the River Sava to Pollution during the Winter
Authors: Zelnik Igor , Sušin Tjaša
Published: December 2020

The aim of the research was to investigate the influence of environmental factors on the structure of epilithic diatom communities in the Sava River from the source to the state border 220 km downstream. The river had numerous human influences along its course, such as municipal and industrial wastewater, agriculture, hydroelectric power plants, etc. The main objective of the research was to find out the influence of human pressure on the structure of the epilithic diatom community under winter and summer conditions. Winter and summer samples were taken at nine sites. At each sampling site, a set of abiotic factors was measured and another set of environmental parameters was evaluated. The analyses showed that nitrogen and phosphorus concentrations increased downstream. We identified 118 different species of diatoms. The most common taxa were Achnanthidium minutissimum and A. pyrenaicum. Planktonic species Cyclotella meneghiniana was only found in the samples of the lower part of the Sava, which is unusual for the epilithic community. The composition of the epilithic diatom community was significantly influenced by conductivity and water temperature, pH and distance from the source. The similarity between diatom communities closer to the source of the river was higher than between communities from the lower part of the Sava River. The values of the trophic and saprobic indices increased downstream and showed that the pollution of the river with nutrients and organic matter increases with the distance from the source. Both indices were significantly higher in winter and showed a more impaired river ecosystem during the winter.
Survival of Selected Pathogenic Bacteria during PDO Pecorino Romano Cheese Ripening
Authors: Lai Giacomo , Melillo Rita , Pes Massimo , Addis Margherita , Fadda Antonio , Pirisi Antonio
Published: December 2020

This study was conducted to assess, for the first time, the survival of the pathogenic bacteria Listeria monocytogenes, Salmonella spp., Escherichia coli O157:H7, and Staphylococcus aureus during the ripening of protected designation of origin (PDO) Pecorino Romano cheese. A total of twenty-four cheese-making trials (twelve from raw milk and twelve from thermized milk) were performed under the protocol specified by PDO requirements. Sheep cheese milk was first inoculated before processing with approximately 106 colony-forming unit (CFU) mL−1 of each considered pathogen and the experiment was repeated six times for each selected pathogen. Cheese composition and pathogens count were then evaluated in inoculated raw milk, thermized milk, and cheese after 1, 90, and 150 days of ripening. pH, moisture, water activity, and salt content of cheese were within the range of the commercial PDO Pecorino Romano cheese. All the cheeses made from raw and thermized milk were microbiologically safe after 90 days and 1 day from their production, respectively. In conclusion, when Pecorino Romano cheese is produced under PDO specifications, from raw or thermized milk, a combination of factors including the speed and extent of curd acidification in the first phase of the production, together with an intense salting and a long ripening time, preclude the possibility of growth and survival of L. monocytogenes, Salmonella spp., and E. coli O157:H7. Only S. aureus can be still detectable at such low levels that it does not pose a risk to consumers.
Bond Graph Modeling and Kalman Filter Observer Design for an Industrial Back-Support Exoskeleton
Authors: Shojaei Barjuei Erfan , Caldwell Darwin G. , Ortiz Jesús
Published: December 2020

This paper presents a versatile approach to the synthesis and design of a bond graph model and a Kalman filter observer for an industrial back-support exoskeleton. Actually, the main purpose of developing a bond graph model is to investigate and understand better the system dynamics. On the other hand, the design of the Kalman observer always should be based on a model providing an adequate description of the system dynamics; however, when back-support exoskeletons are considered, the synthesis of a state observer becomes very challenging, since only nonlinear models may be adopted to reproduce the system dynamic response with adequate accuracy. The dynamic modeling of the exoskeleton robotic platform, used in this work, comprises an electrical brushless DC motor, gearbox transmission, torque sensor and human trunk (biomechanical model). On this basis, a block diagram model of the dynamic system is presented and an experimental test has been carried out for identifying the system parameters accordingly. Both the block diagram and bond graph dynamic models are simulated via MATLAB and 20-sim software (bond graph simulation software) respectively. Furthermore, the possibility of employing the Kalman filter observer together with a suitable linear model is investigated. Subsequently, the performance of the proposed Kalman observer is evaluated in a lifting task scenario with the use of a linear quadratic regulator (LQR) controller with double integral action. Finally, the most important simulation results are presented and discussed.
A ‘Real-Life’ Experience on Automated Digital Image Analysis of FGFR2 Immunohistochemistry in Breast Cancer
Authors: Braun Marcin , Piasecka Dominika , Bobrowski Mateusz , Kordek Radzislaw , Sadej Rafal , Romanska Hanna M.
Published: December 2020

We present here an assessment of a ‘real-life’ value of automated machine learning algorithm (AI) for examination of immunohistochemistry for fibroblast growth factor receptor-2 (FGFR2) in breast cancer (BC). Expression of FGFR2 in BC (n = 315) measured using a certified 3DHistech CaseViewer/QuantCenter software 2.3.0. was compared to the manual pathologic assessment in digital slides (PA). Results revealed: (i) substantial interrater agreement between AI and PA for dichotomized evaluation (Cohen’s kappa = 0.61); (ii) strong correlation between AI and PA H-scores (Spearman r = 0.85, p < 0.001); (iii) a small constant error and a significant proportional error (Passing–Bablok regression y = 0.51 × X + 29.9, p < 0.001); (iv) discrepancies in H-score in cases of extreme (strongest/weakest) or heterogeneous FGFR2 expression and poor tissue quality. The time of AI was significantly longer (568 h) than that of the pathologist (32 h). This study shows that the described commercial machine learning algorithm can reliably execute a routine pathologic assessment, however, in some instances, human expertise is essential.
A Bayesian Entropy Approach to Sectoral Systemic Risk Modeling
Authors: Lupu Radu , Călin Adrian Cantemir , Zeldea Cristina Georgiana , Lupu Iulia
Published: December 2020

We investigate the dynamics of systemic risk of European companies using an approach that merges paradigmatic risk measures such as Marginal Expected Shortfall, CoVaR, and Delta CoVaR, with a Bayesian entropy estimation method. Our purpose is to bring to light potential spillover effects of the entropy indicator for the systemic risk measures computed on the 24 sectors that compose the STOXX 600 index. Our results show that several sectors have a high proclivity for generating spillovers. In general, the largest influences are delivered by Capital Goods, Banks, Diversified Financials, Insurance, and Real Estate. We also bring detailed evidence on the sectors that are the most pregnable to spillovers and on those that represent the main contributors of spillovers.
Four Spacetime Dimensional Simulation of Rheological Waves in Solids and the Merits of Thermodynamics
Authors: Pozsár Áron , Szücs Mátyás , Kovács Róbert , Fülöp Tamás
Published: December 2020

The recent results attained from a thermodynamically conceived numerical scheme applied on wave propagation in viscoelastic/rheological solids are generalized here, both in the sense that the scheme is extended to four spacetime dimensions and in the aspect of the virtues of a thermodynamical approach. Regarding the scheme, the arrangement of which quantity is represented where in discretized spacetime, including the question of appropriately realizing the boundary conditions, is nontrivial. In parallel, placing the problem in the thermodynamical framework proves to be beneficial in regards to monitoring and controlling numerical artefacts—instability, dissipation error, and dispersion error. This, in addition to the observed preciseness, speed, and resource-friendliness, makes the thermodynamically extended symplectic approach that is presented here advantageous above commercial finite element software solutions.
Exploring the Relationship among Predictability, Prediction Accuracy and Data Frequency of Financial Time Series
Authors: Li Shuqi , Lin Aijing
Published: December 2020

In this paper, we aim to reveal the connection between the predictability and prediction accuracy of stock closing price changes with different data frequencies. To find out whether data frequency will affect its predictability, a new information-theoretic estimator Plz, which is derived from the Lempel–Ziv entropy, is proposed here to quantify the predictability of five-minute and daily price changes of the SSE 50 index from the Chinese stock market. Furthermore, the prediction method EEMD-FFH we proposed previously was applied to evaluate whether financial data with higher sampling frequency leads to higher prediction accuracy. It turns out that intraday five-minute data are more predictable and also have higher prediction accuracy than daily data, suggesting that the data frequency of stock returns affects its predictability and prediction accuracy, and that higher frequency data have higher predictability and higher prediction accuracy. We also perform linear regression for the two frequency data sets; the results show that predictability and prediction accuracy are positive related.
Enhance Reliability of Semiconductor Devices in Power Converters
Authors: Nguyen Minh Hoang , Kwak Sangshin
Published: December 2020

As one of the most vulnerable components to temperature and temperature cycling conditions in power electronics converter systems in these application fields as wind power, electric vehicles, drive system, etc., power semiconductor devices draw great concern in terms of reliability. Owing to the wide utilization of power semiconductor devices in various power applications, especially insulated gate bipolar transistors (IGBTs), power semiconductor devices have been studied extensively regarding increasing reliability methods. This study comparatively reviews recent advances in the area of reliability research for power semiconductor devices, including condition monitoring (CM), active thermal control (ATC), and remaining useful lifetime (RUL) estimation techniques. Different from previous review studies, this technical review is carried out with the aim of providing a comprehensive overview of the correlation between various enhancing reliability techniques and discussing the corresponding merits and demerits by using 144 related up-to-date papers. The structure and failure mechanism of power semiconductor devices are first investigated. Different failure indicators and recent associated CM techniques are then compared. The ATC approaches following the type of converter systems are further summarized. Furthermore, RUL estimation techniques are surveyed. This paper concludes with summarized challenges for future research opportunities regarding reliability improvement.
Low-Complexity Address Generation for Multiuser Detectors in IDMA Systems
Authors: Kong Byeong Yong
Published: December 2020

This paper presents a low-complexity address generation unit (AGU) for multiuser detectors in interleave division multiple access (IDMA) systems. To this end, for the first time, all possible options for designing AGUs are first analyzed in detail. Subsequently, a complexity reduction technique is applied to each of those architectures. More specifically, some components in AGUs are relocated to make them shareable and removable without affecting the functionality. The complete transparency of such renovation makes it applicable to any existing multiuser detector without tailoring the interfacing components therein. Measuring the hardware complexity, all the resulting AGUs are compared with each other, and a new architecture simpler than the state-of-the-art one is developed. Implementation results in a 65 nm CMOS process, demonstrating that the proposed AGU can alleviate the equivalent gate count and the power consumption of the prior process by 13% and 31%, respectively.
A Novel Metal Foreign Object Detection for Wireless High-Power Transfer Using a Two-Layer Balanced Coil Array with a Serial-Resonance Maxwell Bridge
Authors: Kim Sunhee , Jung Haeyong , Ju Youngjun , Lim Yongseok
Published: December 2020

In a wireless high-power transfer system with a distance of several tens of centimeters apart between the transmitter and receiver coils, one of the most challenging issues is to detect metallic foreign objects between the transmitter and receiver coils. The metallic foreign objects must be detected and removed since these reduce the transmission efficiency and cause heat generation of the transmitter and receiver. This paper presents two-layer symmetric balanced coil array so that if there are metallic foreign objects, it can be detected through the change of the inductance of the balanced coils. Since the balanced coil is composed of coils that are in a symmetrical relationship in position, there is no need for a reference coil, and interference between coils is reduced by dividing the coil into two layers. In addition, a novel serial-resonance Maxwell bridge circuit to improve the inductance change detection performance is presented in this paper. The proposed metallic foreign object detection system is implemented using two-layer balanced coil array with a serial-resonance Maxwell bridge and the experimental results show that voltage changes of hundreds of mV to several V occur when a metallic foreign object is inserted, so that even small metals such as clips can be detected.
WIoTED: An IoT-Based Portable Platform to Support the Learning Process Using Wearable Devices
Authors: López Camacho Vicente López , de la Guía Elena , Orozco-Barbosa Luis , Olivares Teresa
Published: December 2020

In recent years, we have witnessed an exponential growth in the use wearable and Internet of Things devices to provide friendly and tangible interfaces for ubiquitous services. The digital transformation of private and public organizations has been largely spurred by the widespread use of mobile devices, such as smartphones, tablets and virtual reality gadgets. Tangible interfaces have further enhanced the quality of experience by enabling the customization of human–machine interfaces. This paper presents WIoTED: a platform integrating wearable and IoT technologies specifically designed for the delivery and support of learning/teaching activities. Among its main features, WIoTED introduces MovED: a wearable device designed to facilitate both the orchestration of enriching teaching environments and use by young learners. Based on numerous trials conducted under various scenarios, we have validated the operation of WIoTED in terms of the education delivery effectiveness: usability and user satisfaction. Our study includes a comparison in terms of the workload generated and response time bounds delivered by MovED with respect to a setup preferring the use of smartphones.
Effect of Receiver’s Tilted Angle on the Capacity for Underwater Wireless Optical Communication
Authors: Ju Meiyan , Huang Ping , Li Yueheng , Shi Hongqiang
Published: December 2020

This paper focuses on the effect of the receiver’s tilted angle on the capacity of a clear ocean water Underwater Wireless Optical Communication (UWOC) system. To achieve this goal, the relationship between the channel capacity and the receiver’s tilted angle is investigated. First, we propose a double-exponential fading model with pointing error which can more accurately depict the channel of clear ocean water UWOC instead of the traditional Beer’s law model. Based on this channel model, we present the close-form expression of the capacity bounds of the UWOC system. Then, an optimization problem is formulated to improve the capacity by tilting the receiving plane. Both theoretical analyses and simulation results verify that the capacity bounds of UWOC can be enhanced dramatically by tilting the receiver plane at an optimal angle. Thus, in practice, we can provide an effective design strategy for a UWOC system.
An Optimization Method for Simultaneous Wireless Power and Data Transfer Systems
Authors: Wang Peiyue , Sun Yue , Li Xiaofei , Ye Zhaohong
Published: December 2020

Simultaneous wireless power and data transfer (SWPDT) technology is usually needed in wireless power transfer (WPT) systems. In this paper, to achieve the efficient and stable SWPDT, the signal to noise rate (SNR) is first optimized through the analysis of data transmission gain and the interference of power transfer on data transfer. In order to reduce the interference of power channel to data transfer channel, the compensation topology of double-sided LCC and the band-stop networks are used. To solve the problem of SNR limitation, the coupling relationships between each circuit are taken into consideration and a matching method of resonance parameters to improve the SNR is presented. Based on the relationship between SNR and the parameters of data transfer channel, an optimization design method focused on parameters of data transfer channel for improving the SNR is presented. Finally, the feasibility and the correctness of the parameter design method proposed in this paper is verified by simulation and experiment.