bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Macrophage Immune Responses and Metabolic Reprogramming in Smooth and Rough Variant Infections of Mycobacterium mucogenicum
Authors: Kang Minji , Kim Ho Won , Yu A-Reum , Yang Jeong Seong , Lee Seung Heon , Lee Ji Won , Yoon Hoe Sun , Lee Byung Soo , Park Hwan-Woo , Lee Sung Ki , Lee Seungwan , Whang Jake , Kim Jong-Seok
Published: February 2022

Mycobacterium mucogenicum (Mmuc), a rapidly growing nontuberculous mycobacterium (NTM), can infect humans (posttraumatic wound infections and catheter-related sepsis). Similar to other NTM species, Mmuc exhibits colony morphologies of rough (Mmuc-R) and smooth (Mmuc-S) types. Although there are several case reports on Mmuc infection, no experimental evidence supports that the R-type is more virulent. In addition, the immune response and metabolic reprogramming of Mmuc have not been studied on the basis of morphological characteristics. Thus, a standard ATCC Mmuc strain and two clinical strains were analyzed, and macrophages were generated from mouse bone marrow. Cytokines and cell death were measured by ELISA and FACS, respectively. Mitochondrial respiration and glycolytic changes were measured by XF seahorse. Higher numbers of intracellular bacteria were found in Mmuc-R-infected macrophages than in Mmuc-S-infected macrophages. Additionally, Mmuc-R induced higher levels of the cytokines TNF-α, IL-6, IL-12p40, and IL-10 and induced more BMDM necrotic death. Furthermore, our metabolic data showed marked glycolytic and respiratory differences between the control and each type of Mmuc infection, and changes in these parameters significantly promoted glucose metabolism, extracellular acidification, and oxygen consumption in BMDMs. In conclusion, at least in the strains we tested, Mmuc-R is more virulent, induces a stronger immune response, and shifts bioenergetic metabolism more extensively than the S-type. This study is the first to report differential immune responses and metabolic reprogramming after Mmuc infection and might provide a fundamental basis for additional studies on Mmuc pathogenesis.
The Effect of Meclofenoxate on the Transcriptome of Aging Brain of Nothobranchius guentheri Annual Killifish
Authors: Bakhtogarimov Ildar R. , Kudryavtseva Anna V. , Krasnov George S. , Gladysh Natalya S. , Volodin Vsevolod V. , Kudryavtsev Alexander A. , Bulavkina Elizaveta V. , Goncharova Margarita A. , Ledyaeva Veronika S. , Pastukhov Ivan S. , Vershinina Yulia S. , Starkova Anna M. , Snezhkina Anastasiya V. , Shuvalova Anastasija I. , Pavlov Vladislav S. , Nikiforov-Nikishin Dmitry L. , Moskalev Alexey A. , Guvatova Zulfiya G.
Published: February 2022

Annual fish of the genus Nothobranchius are promising models for aging research. Nothobranchius reproduces typical aspects of vertebrate aging, including hallmarks of brain aging. Meclofenoxate (MF) is a well-known compound that can enhance cognitive performance. The drug is prescribed for asthenic conditions, trauma, and vascular diseases of the brain. It is believed that MF is able to delay age-dependent changes in the human brain. However, until now, there has been no study of the MF effect on the brain transcriptome. In the present work, we performed an RNA-Seq study of brain tissues from aged Nothobranchius guentheri, which were almost lifetime administered with MF, as well as young and aged control fish. As expected, in response to MF, we revealed significant overexpression of neuron-specific genes including genes involved in synaptic activity and plasticity, neurotransmitter secretion, and neuron projection. The effect was more pronounced in female fish. In this aspect, MF alleviated age-dependent decreased expression of genes involved in neuronal activity. In both treated and untreated animals, we observed strong aging-associated overexpression of immune and inflammatory response genes. MF treatment did not prevent this effect, and moreover, some of these genes tended to be slightly upregulated under MF treatment. Additionally, we noticed upregulation of some genes associated with aging and cellular senescence, including isoforms of putative vascular cell adhesion molecule 1 (VCAM1), protein O-GlcNAcase (OGA), protein kinase C alpha type (KPCA), prolow-density lipoprotein receptor-related protein 1 (LRP1). Noteworthy, MF treatment was also associated with the elevated transcription of transposons, which are highly abundant in the N. guentheri genome. In conclusion, MF compensates for the age-dependent downregulation of neuronal activity genes, but its effect on aging brain transcriptome still cannot be considered unambiguously positive.
Changes in Non-Deamidated versus Deamidated Epitope Targeting and Disease Prediction during the Antibody Response to Gliadin and Transglutaminase of Infants at Risk for Celiac Disease
Authors: Diós Ádám , Srinivasan Bharani , Gyimesi Judit , Werkstetter Katharina , Valenta Rudolf , Koletzko Sibylle , Korponay-Szabó Ilma R.
Published: February 2022

Celiac disease (CeD) is a conditional autoimmune disorder with T cell-mediated immune response to gluten coupled with antibody production to gliadin and the self-protein tissue transglutaminase (TG2). TG2 contributes to the CeD pathomechanism by deamidating gliadin, thereby generating more immunogenic peptides. Anti-gliadin antibodies may appear before the autoantibody production. The scope of this study was to dissect these early antibody responses by investigating serum samples collected during the PreventCD prospective double-blind study, where infants with high CeD risk were randomized to 200 mg daily gluten intake or placebo from 4 to 6 months of age, followed by frequent blood testing on regular gluten consumption in both groups. After primary gluten intake, children with or without later CeD produced IgA and IgG antibodies which preferentially recognized non-deamidated gliadin peptides. At CeD development with anti-TG2 seroconversion, there was a significant increase in the antibody reaction toward deamidated gliadin peptides (DGP), with maturation in the binding strength for the PEQPFP gamma-gliadin core peptide. The earliest produced autoantibodies targeted TG2’s celiac epitope 2. Our results reveal a qualitative change in the gliadin-directed humoral immune response at the time when anti-TG2 antibodies appear, but anti-DGP antibodies in the absence of anti-TG2 antibodies are not disease-predictive.
Immunomodulatory and Allergenic Properties of Antimicrobial Peptides
Authors: Guryanova Svetlana V. , Ovchinnikova Tatiana V.
Published: February 2022

With the growing problem of the emergence of antibiotic-resistant bacteria, the search for alternative ways to combat bacterial infections is extremely urgent. While analyzing the effect of antimicrobial peptides (AMPs) on immunocompetent cells, their effect on all parts of the immune system, and on humoral and cellular immunity, is revealed. AMPs have direct effects on neutrophils, monocytes, dendritic cells, T-lymphocytes, and mast cells, participating in innate immunity. They act on B-lymphocytes indirectly, enhancing the induction of antigen-specific immunity, which ultimately leads to the activation of adaptive immunity. The adjuvant activity of AMPs in relation to bacterial and viral antigens was the reason for their inclusion in vaccines and made it possible to formulate the concept of a “defensin vaccine” as an innovative basis for constructing vaccines. The immunomodulatory function of AMPs involves their influence on cells in the nearest microenvironment, recruitment and activation of other cells, supporting the response to pathogenic microorganisms and completing the inflammatory process, thus exhibiting a systemic effect. For the successful use of AMPs in medical practice, it is necessary to study their immunomodulatory activity in detail, taking into account their pleiotropy. The degree of maturity of the immune system and microenvironment can contribute to the prevention of complications and increase the effectiveness of therapy, since AMPs can suppress inflammation in some circumstances, but aggravate the response and damage of organism in others. It should also be taken into account that the real functions of one or another AMP depend on the types of total regulatory effects on the target cell, and not only on properties of an individual peptide. A wide spectrum of biological activity, including direct effects on pathogens, inactivation of bacterial toxins and influence on immunocompetent cells, has attracted the attention of researchers, however, the cytostatic activity of AMPs against normal cells, as well as their allergenic properties and low stability to host proteases, are serious limitations for the medical use of AMPs. In this connection, the tasks of searching for compounds that selectively affect the target and development of an appropriate method of application become critically important. The scope of this review is to summarize the current concepts and newest advances in research of the immunomodulatory activity of natural and synthetic AMPs, and to examine the prospects and limitations of their medical use.
Towards Next-Generation Sequencing (NGS)-Based Newborn Screening: A Technical Study to Prepare for the Challenges Ahead
Authors: Veldman Abigail , Kiewiet Mensiena B. G. , Heiner-Fokkema Margaretha Rebecca , Nelen Marcel R. , Sinke Richard J. , Sikkema-Raddatz Birgit , Voorhoeve Els , Westra Dineke , Dollé Martijn E. T. , Schielen Peter C. J. I. , van Spronsen Francjan J.
Published: February 2022

Newborn screening (NBS) aims to identify neonates with severe conditions for whom immediate treatment is required. Currently, a biochemistry-first approach is used to identify these disorders, which are predominantly inherited meta1bolic disorders (IMD). Next-generation sequencing (NGS) is expected to have some advantages over the current approach, for example the ability to detect IMDs that meet all screening criteria but lack an identifiable biochemical footprint. We have now designed a technical study to explore the use of NGS techniques as a first-tier approach in NBS. Here, we describe the aim and set-up of the NGS-first for the NBS (NGSf4NBS) project, which will proceed in three steps. In Step 1, we will identify IMDs eligible for NGS-first testing, based on treatability. In Step 2, we will investigate the feasibility, limitations and comparability of different technical NGS approaches and analysis workflows for NBS, eventually aiming to develop a rapid NGS-based workflow. Finally, in Step 3, we will prepare for the incorporation of this workflow into the existing Dutch NBS program and propose a protocol for referral of a child after a positive NGS test result. The results of this study will be the basis for an additional analytical route within NBS that will be further studied for its applicability within the NBS program, e.g., regarding the ethical, legal, financial and social implications.
Chronology of Four Climbing Dune Outcrops on the Atlantic Coast of Galicia (NW Spain) Linked to the Sea Level Fall during the MIS6 and MIS4 Isotopic Stages
Authors: Arce-Chamorro Carlos , Vidal-Romaní Juan Ramón , Sanjurjo-Sánchez Jorge
Published: February 2022

Numerous sandy deposits, interpreted as the remains of old climbing dunes, are preserved on the cliffy coast of Galicia (northwest Spain). These deposits can be found both in open coastal areas and in the interior of the Galician Rias. In this paper, a formation age is established for four aeolianite outcrops dating back to 166 ± 9 ka, 131 ± 6 ka, 128 ± 18 ka and 62 ± 3 ka, using the IRSL290 signal of feldspars. These sands were mobilised by coastal winds from a sea level lower than the current one during MIS6 and MIS4. The sea level fall during these regressive episodes shifted the coastline several kilometres away from its current position. This favoured the action of the wind blowing over the emerged coastal strip, which acted as a source area for aeolian sands. During warmer episodes, such as the Eemian and the Holocene, the advance of the sands onto the coast was progressively reduced as the sea level rose and the oceanic waters flooded the continental shelf.
Fourth-Order Comprehensive Adjoint Sensitivity Analysis Methodology for Nonlinear Systems (4th-CASAM-N): II. Application to a Nonlinear Heat Conduction Paradigm Model
Authors: Cacuci Dan Gabriel
Published: February 2022

This work illustrates the application of the fourth-order comprehensive sensitivity analysis methodology for nonlinear systems (abbreviated as “4th-CASAM-N”), which enables the efficient computation of exactly determined 1st-, 2nd-, 3rd-, and 4th-order functional derivatives of results produced by computational models with respect to the model’s parameters. Results produced by computational models are called model “responses” and the respective functional derivatives are called “sensitivities” (with respect) to model parameters. The qualifier “comprehensive” indicates that the 4th-CASAM-N methodology enables the exact and efficient computation not only of response sensitivities with respect to customary model parameters (including computational input data, correlations, initial and/or boundary conditions) but also with respect to imprecisely known material boundaries, as would be caused by manufacturing tolerances. The 4th-CASAM-N enables the hitherto very difficult, if not intractable, exact computation of all of the 1st-, 2nd-, 3rd-, and 4th-order response sensitivities for large-scale systems involving many parameters, as usually encountered in practice. A paradigm model that describes nonlinear heat conduction through a material has been chosen to illustrate the application of the 4th-CASAM-N methodology, as this model enables the derivation of tractable closed-form analytical expressions of representative 1st-, 2nd-, 3rd-, and 4th-order response sensitivities while largely avoiding side-tracking algebraic manipulations. The responses chosen for this paradigm model include not only physically measurable quantities but also a synthetic response designed to illustrate the enormous possible reduction in the number of computation when using the 4th-CASAM-N (rather than other methods) for computing response sensitivities.
Mean–Variance Portfolio Efficiency under Leverage Aversion and Trading Impact
Authors: Edirisinghe Chanaka , Jeong Jaehwan
Published: February 2022

This paper addresses the optimal rebalancing problem of a long–short portfolio with high net asset value under trading impact losses. The fund manager may employ leveraging as a tool to increase portfolio returns. However, to mitigate potential leverage risks, frequent rebalancing may become necessary, which leads to significant slippage losses that dampen portfolio performance ex post. We consider the problem in an integrated framework by incorporating trading impact and leverage restrictions ex ante within a mean–variance framework, where leverage control is imposed using a chance constraint. The resulting mean–variance–leverage optimization model (MVL) is non-convex, and we develop an efficient scheme to obtain the optimal portfolio. We investigate how portfolio leverage modifies the MV efficient frontier in the presence of trading impact, and highlight the significant outperformance of the proposed model relative to the standard mean–variance model. Increased target means require less restrictions on leverage, which result in higher rates of slippage losses. Our analysis supports the notion that leverage restrictions contribute to choosing high beta assets, even in the presence of trading impact.
Corporate Social Responsibility and Capital Allocation Efficiency in Australia and New Zealand
Authors: Garel Alexandre , Tourani-Rad Alireza , Xu Shengze
Published: February 2022

In this paper, we investigate whether a firm’s Corporate Social Responsibility initiatives could affect its financial performance. We specifically investigate the firm’s capital allocation efficiency as a moderating channel affecting their performance. We employ a comprehensive sample of Australian and New Zealand stock exchange-listed firms consisting of 3324 firm-year observations for the period 2004–2017. We do not find that the firm’s capital allocation efficiency is negatively affected by the overall CSR scores or its two main components, namely the environmental or social dimensions. However, our empirical analysis exposes a challenging result for the firms in that we find strong evidence that extremely costly environmental CSR initiatives or policies (e.g., emission reduction, employee health and safety improvements, clean energy products) could reduce the firm’s investment efficiency. Hence, firms need to follow a balancing act when contemplating CSR plans and investing in them. While investors appreciate moderate levels of investment in CSRs, they penalize those firms that invest excessively in such initiatives.
Provision of Allotment Gardens and Its Influencing Factors: A Case Study of Tokyo, Japan
Authors: Zheng Hua , Akita Noriko , Araki Shoko , Fukuda Masayo
Published: February 2022

Allotment gardens (AGs) are widely used in metropolitan areas around the world to offer agricultural opportunities to urban residents. However, there are not enough individual plots for residents to rent for urban gardening, and research on AGs from a city-wide perspective is ongoing. In addition, AGs have a long history in Tokyo, yet few international studies on the current situation of AGs have addressed Asian cities. Thus, this study intends to analyze the provision of AGs and its influencing factors in Tokyo. Using ArcGIS combined the 472-points dataset created by geo-coordinate mapping with urban GIS data to reveal spatial characteristics in four dimensions. Results demonstrate that most AGs are in the urbanization promotion area; most municipalities have AGs; AGs are concentrated within 20 to 30 km from the center of Tokyo; the AGs’ clusters are located at the municipal boundaries. We conducted multiple regressions to determine the influencing factors at the municipal level, with the provision that AGs are related to population density, land price, and the ratio of productive green space. The policy implication of this study is that policymakers need to consider the siting strategy of AGs based on spatial characteristics of AGs.
From Latin to Modern Italian: Some Notes on Negation
Authors: Greco Matteo
Published: February 2022

This article aims at investigating some diachronic aspects of the Italian negative system, considering a time span ranging from Old Latin to Modern Italian. Most of the negative polarity phenomena populating the Modern Italian system are consequences of a crucial change that occurred in Old Latin: The Latin negative morpheme nōn (“not”), which initially displayed a maximal projection status, and became a syntactic (negative) head. This change caused the shift from a double negation system to a negative concord one, which affects many Romance languages (and their dialects). It also determines the availability of the expletive reading of negation in Italian, as well as in other Romance languages (ex. French), calling for a new generalization: only languages (and structures) displaying a negative head allow the expletive interpretation of negation, languages displaying a maximal projection status do not.
Investigation of Self-Healing Mortars with and without Bagasse Ash at Pre- and Post-Crack Times
Authors: Tesfamariam Belay Brehane , Seyoum Redeat , Andoshe Dinsefa Mensur , Terfasa Tatek Temesgen , Ahmed Gulam Mohammed Sayeed , Badruddin Irfan Anjum , Khaleed H.M.T.
Published: February 2022

Cracks in typical mortar constructions enhance water permeability and degrade ions into the structure, resulting in decreased mortar durability and strength. In this study, mortar samples are created that self-healed their cracks by precipitating calcium carbonate into them. Bacillus subtilus bacterium (10−7, 10−9 cells/mL), calcium lactate, fine aggregate, OPC-cement, water, and bagasse ash were used to make self-healing mortar samples. Calcium lactates were prepared from discarded eggshells and lactic acid to reduce the cost of self-healing mortars, and 5% control burnt bagasse ash was also employed as an OPC-cement alternative. In the presence of moisture, the bacterial spores in mortars become active and begin to feed the nutrient (calcium lactate). The calcium carbonate precipitates and plugs the fracture. Our experimental results demonstrated that cracks in self-healing mortars containing bagasse ash were largely healed after 3 days of curing, but this did not occur in conventional mortar samples. Cracks up to 0.6 mm in self-healing mortars were filled with calcite using 10−7 and 10−9 cell/mL bacteria concentrations. Images from an optical microscope, X-ray Diffraction (XRD), and a scanning electron microscope (SEM) were used to confirm the production of calcite in fractures. Furthermore, throughout the pre- and post-crack-development stages, self-healing mortars have higher compressive strength than conventional mortars. The precipitated calcium carbonates were primed to compact the samples by filling the void spaces in hardened mortar samples. When fissures developed in hardened mortars, bacteria became active in the presence of moisture, causing calcite to precipitate and fill the cracks. The compressive strength and flexural strength of self-healing mortar samples are higher than conventional mortars before cracks develop in the samples. After the healing process of the broken mortar parts (due to cracking), self-healing mortars containing 5% bagasse ash withstand a certain load and have greater flexural strength (100 kPa) than conventional mortars (zero kPa) at 28 days of cure. Self-healing mortars absorb less water than typical mortar samples. Mortar samples containing 10−7 bacteria cells/mL exhibit greater compressive strength, flexural strength, and self-healing ability. XRD and SEM were used to analyze mortar samples with healed fractures. XRD, FTIR, and SEM images were also used to validate the produced calcium lactate. Furthermore, the durability of mortars was evaluated using DTA-TGA analysis and water absorption tests.
The Effects of Geometry Size and Initial Microstructure on Deformation Behavior of Electrically-Assisted Micro-Compression in Ti-6Al-4V Alloy
Authors: Bao Jianxing , Lv Shoudan , Wang Bo , Shan Debin , Guo Bin , Xu Jie
Published: February 2022

In this study, electrically-assisted micro-compression (EAMC) tests were conducted for cylindrical specimens of Ti-6Al-4V alloy with four geometric sizes and three initial microstructures. The result showed that the specimen temperature nonlinearly increased with the square of current density. The quasi-static heat equilibrium equation was established to quantify the effects of the scale factor on the Joule heat temperature. Moreover, it was demonstrated that the Joule temperature scale effect had a greater effect on the flow stress than the sample size effect for specimens of different dimensions. It was noted that the 0.5 mm diameter sample displayed abnormal deformation behavior, which was related to surface oxidation leading a brittle surface layer. By comparison of the microstructures, it was found that the α→β phase transformation occured below the β transus temperature, which was attributed to the local Joule heat effect and the scattering of drift electrons during EAMC. Furthermore, the flow curves showed a strong dependence of the strength and ductility on the initial microstructure. The widmannstatten microstructure exhibited higher strength, smaller hardening rate and more easy flow localization compared with basket-weave microstructures, which was attributed to the low β phase content and narrow interlamellar spacing of α lamellae grains in the widmannstatten microstructure.
A New Wood Adhesive Based on Recycling Camellia oleifera Cake-Protein: Preparation and Properties
Authors: Deng Xue , Wu Zhigang , Zhang Bengang , Lei Hong , Liang Jiankun , Li Lifen , Tu Yuan , Li De , Xiao Guoming
Published: February 2022

In order to improve the initial viscosity and stability of Camellia oleifera cake-protein adhesive, Camellia oleifera cake-protein was blended with defatted soybean protein (DSP), soybean protein isolate (SPI), and casein, followed by adhesive preparation through degradation and crosslinking methods. The performance of Camellia oleifera cake-protein adhesive was investigated by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), scanning electron microscopic (SEM), and thermogravimetric (TG) and X-ray diffraction (XRD). The results showed that DSP, SPI, and casein likely promoted the effective degradation of Camellia oleifera cake-protein, and, thus, more active groups were formed in the system, accompanied by more reactivity sites. The prepared adhesive had a lower curing temperature, and higher initial viscosity and stability, but the storage time was shortened. Moreover, DSP, SPI, and casein, themselves, were degraded into peptide chains with lower molecular weights; thus, improving the overall flexibility of the adhesive, facilitating a better elastic contact and regular array between crosslinking products, and further strengthening the crosslinked structure and density of the products. After curing, a compact and coherent reticular structure was formed in the adhesive layer, with both bonding strength and water resistance being significantly improved. According to the results obtained, the next step will be to study the DSP-modified Camellia oleifera cake-protein adhesive in depth.
Prediction of Compressive Strength of Partially Saturated Concrete Using Machine Learning Methods
Authors: Candelaria Ma. Doreen Esplana , Kee Seong-Hoon , Lee Kang-Seok
Published: February 2022

The aim of this research is to recommend a set of criteria for estimating the compressive strength of concrete under marine environment with various saturation and salinity conditions. Cylindrical specimens from three different design mixtures are used as concrete samples. The specimens are subjected to different saturation levels (oven-dry, saturated-surface dry and three partially dry conditions: 25%, 50% and 75%) on water and water–NaCl solutions. Three parameters (P- and S-wave velocities and electrical resistivity) of concrete are measured using two NDT equipment in the laboratory while two parameters (density and water-to-binder ratio) are obtained from the design documents of the concrete cylinders. Three different machine learning methods, which include, artificial neural network (ANN), support vector machine (SVM) and Gaussian process regression (GPR), are used to obtain multivariate prediction models for compressive strength from multiple parameters. Based on the R-squared value, ANN results in the highest accuracy of estimation while GPR gives the lowest root-mean-squared error (RMSE). Considering both the data analysis and practicality of the method, the prediction model based on two NDE parameters (P-wave velocity measurement and electrical resistivity) and one design parameter (water-to-binder ratio) is recommended for assessing compressive strength under marine environment.
Effect of Glass Composition on Luminescence and Structure of CsPbBr3 Quantum Dots in an Amorphous Matrix
Authors: Zheng Ruilin , Ueda Jumpei , Shinozaki Kenji , Tanabe Setsuhisa
Published: February 2022

Glass matrix embedding is an efficient way to improve the chemical and thermal stability of the halide perovskite QDs. However, CsPbX3 QDs exhibit distinct optical properties in different glass matrixes, including photoluminescence (PL) peak position, PL peak width, and optical band gap. In this work, the temperature-dependent PL spectra, absorption spectra, high-energy X-ray structure factor S(Q), and pair distribution function (PDF) were integrated to analyze the structural evolution of CsPbBr3 QDs in different glass matrixes. The results show that the lattice parameters and atomic spacing of CsPbBr3 QDs are affected by the glass composition in which they are embedded. The most possibility can be attributed to the thermal expansion mismatch between CsPbBr3 QDs and the glass matrix. The results may provide a new way to understand the effect of the glass composition on the optical properties of CsPbBr3 QDs in a glass matrix.
Sunlike White Light-Emitting Diodes Based on Rare-Earth-Free Luminescent Materials
Authors: Menéndez-Velázquez Amador , Morales Dolores , García-Delgado Ana Belén
Published: February 2022

Solid-state lighting (SSL) sources based on light-emitting diodes represent the new generation of highly efficient illumination systems that significantly impact energy-saving. The development of white light-emitting diodes (WLEDs) with a combination of high color rendering index (CRI) and high deep-red color rendering R9 is an important challenge in the field of solid-state lighting. On the other hand, most WLEDs use rare-earth inorganic luminescent materials. The annual demand for rare-earth metals has doubled to 125,000 tons in 15 years, and the demand is projected to reach 315,000 tons in 2030. The explosion in demand for these materials, combined with a monopolistic supply source, represents a real risk for the development of WLEDs in the next few years. Luminescent organic materials are a relevant and promising alternative. Here, we report a WLED with a very high CRI of 95.7 and R9 of 78.7, obtained using a combination of a blue LED chip (excitation source) and two organic luminescent dyes (Coumarin 6 and Lumogen Red) acting as spectral converters in a multilayer remote phosphor configuration. To the best of our knowledge, this is the first rare-earth-free WLED with such high values of CRI and R9.
Fine Piercing of Amorphous Electrical Steel Sheet Stack by Micro-/Nano-Textured Punch
Authors: Komori Yukiya , Suzuki Yohei , Abe Kohta , Aizawa Tatsuhiko , Shiratori Tomomi
Published: February 2022

The periodic nanotexture was superposed to the micro-textured grooves on the side surface of the punch. These grooves with nanotextures were shaped to have parallel and vertical orientations to the punch stroke direction, respectively. A stack of five amorphous electrical steel sheets was punched out with these micro-/nano-textured punches. The process affected zone at the vicinity of the punched hole was analyzed by SEM (Scanning Electron Microscopy) and a three-dimensional profilometer. The punch surfaces were also observed by SEM to describe the debris particle adhesion on them. The dimensional change in each layer of the stack before and after perforation was measured to describe the punching behavior with the comparison to the punch diameter.
Treatment of Infection-Related Non-Unions with Bioactive Glass—A Promising Approach or Just Another Method of Dead Space Management?
Authors: Freischmidt Holger , Armbruster Jonas , Rothhaas Catharina , Titze Nadine , Guehring Thorsten , Nurjadi Dennis , Sonntag Robert , Schmidmaier Gerhard , Grützner Paul Alfred , Helbig Lars
Published: February 2022

The treatment of infected and non-infected non-unions remains a major challenge in trauma surgery. Due to the limited availability of autologous bone grafts and the need for local anti-infective treatment, bone substitutes have been the focus of tissue engineering for years. In this context, bioactive glasses are promising, especially regarding their anti-infective potential, which could reduce the need for local and systemic treatment with conventional antibiotics. The aim of this study was to investigate the osteoinductive and osteoconductive effects, as well as the anti-infectious potential, of S53P4 using a standardized non-union model, which had not been investigated previously. Using an already established sequential animal model in infected and non-infected rat femora, we were able to investigate bioactive glass S53P4 under realistic non-union conditions regarding its osteoinductive, osteoconductive and anti-infective potential with the use of µCT scans, biomechanical testing and histological, as well as microbiological, analysis. Although S53P4 did not lead to a stable union in the non-infected or the infected setting, µCT analysis revealed an osteoinductive effect of S53P4 under non-infected conditions, which was diminished under infected conditions. The osteoconductive effect of S53P4 remained almost negligible in histological analysis, even 8 weeks after treatment. Additionally, the expected anti-infective effect could not be demonstrated. Our data suggested that S53P4 should not be used in infected non-unions, especially in those with large bone defects.
Numerical Simulation of Conical and Linear-Shaped Charges Using an Eulerian Elasto-Plastic Multi-Material Multi-Phase Flow Model with Detonation
Authors: Yeom Geum-Su
Published: February 2022

This study developed a hydrocode to numerically simulate both conical and linear-shaped charges using an Eulerian multi-material and multi-phase flow model. Elasto-plastic solids and the detonation of a high explosive charge were modeled using a Johnson–Cook material model and the programmed burn model, respectively. Further, the plasticity of the solids was calculated using a radial return mapping algorithm. The model was solved using a high-resolution computational fluid dynamics (CFD) technique on Cartesian grids. Material interfaces were tracked using the level-set method, and the boundary conditions were imposed using the ghost fluid method. The developed hydrocode was validated using high-speed impact problems. Consequently, the developed hydrocode was used to successfully simulate the evolution and penetration of metal jets in shaped charges after a detonation.
Experimental Study on the Internal Pressure Pulsation Characteristics of a Bidirectional Axial Flow Pump Operating in Forward and Reverse Directions
Authors: Zhang Xiaowen , Tang Fangping , Chen Yueting , Huang Congbing , Chen Yujun , Wang Lin , Shi Lijian
Published: February 2022

A bidirectional axial flow pump can realize bidirectional pumping, which has a wide application prospect in coastal low-head pumping stations and water jet propulsion systems. In this paper, a typical bidirectional axial flow pump is taken as the research object, and the hydraulic model of the bidirectional axial flow pump is manufactured. The hydrodynamic characteristics of the bidirectional axial flow pump are tested on the high-precision hydraulic mechanical test bench, including the positive and negative directions. In the experiment, multiple pressure pulsation monitoring points were arranged in the impeller chamber, and the pressure fluctuations in the pump under a total of 42 flow conditions were measured by a micro pressure pulsation sensor, involving 21 working conditions of forward operation and 21 working conditions of reverse operation. According to the experimental results, the hydrodynamic characteristics, especially the pressure pulsation characteristics in the pump, of the two-way axial flow pump under positive and negative operation are comprehensively compared and analyzed, and the energy characteristics and the propagation law of pressure pulsation of the two-way axial flow pump under positive and negative operation are revealed. The research results provide an important reference for the safe and stable operation of coastal bidirectional axial flow pump stations.
Deep Red Lesion Classification for Early Screening of Diabetic Retinopathy
Authors: Ashraf Muhammad Nadeem , Hussain Muhammad , Habib Zulfiqar
Published: February 2022

Diabetic retinopathy (DR) is an asymptotic and vision-threatening complication among working-age adults. To prevent blindness, a deep convolutional neural network (CNN) based diagnosis can help to classify less-discriminative and small-sized red lesions in early screening of DR patients. However, training deep models with minimal data is a challenging task. Fine-tuning through transfer learning is a useful alternative, but performance degradation, overfitting, and domain adaptation issues further demand architectural amendments to effectively train deep models. Various pre-trained CNNs are fine-tuned on an augmented set of image patches. The best-performing ResNet50 model is modified by introducing reinforced skip connections, a global max-pooling layer, and the sum-of-squared-error loss function. The performance of the modified model (DR-ResNet50) on five public datasets is found to be better than state-of-the-art methods in terms of well-known metrics. The highest scores (0.9851, 0.991, 0.991, 0.991, 0.991, 0.9939, 0.0029, 0.9879, and 0.9879) for sensitivity, specificity, AUC, accuracy, precision, F1-score, false-positive rate, Matthews’s correlation coefficient, and kappa coefficient are obtained within a 95% confidence interval for unseen test instances from e-Ophtha_MA. This high sensitivity and low false-positive rate demonstrate the worth of a proposed framework. It is suitable for early screening due to its performance, simplicity, and robustness.
Stochastic Game Analysis of Cooperation and Selfishness in a Random Access Mechanism
Authors: Boujnoui Ahmed , Zaaloul Abdellah , Orozco-Barbosa Luis , Haqiq Abdelkrim
Published: February 2022

This paper introduces a general stochastic game analysis of a network scenario consisting of a mix of cooperative and non-cooperative players (i.e., users) under incomplete game information. Users access a shared channel using the Slotted ALOHA mechanism combined with ZigZag Decoding (SAZD). Cooperative players seek to optimize the global utility of the system (e.g., throughput, delay, loss rate) regardless of their individual interests, whereas non-cooperative players act selfishly and optimize their own benefits irrespective of the impact of this behavior on others and on the entire network system. The game equilibrium is characterized by the social optimum and the Nash equilibrium, where the former is adopted by cooperative players and the latter is the equilibrium strategy of non-cooperative players. We undertake a comparative study across two game scenarios with different levels of cooperation and selfishness. Our results generally show that the information possessed by a player can determine the outcome. Furthermore, our findings show that the network performance is strongly influenced by selfish behavior, which can lead to a significant disruption of the entire system. Finally, we show a possible scenario in which the network could greatly benefit from this selfish behavior thanks to the ZigZag scheme.
Clique Search in Graphs of Special Class and Job Shop Scheduling
Authors: Szabó Sándor , Zaválnij Bogdán
Published: February 2022

In this paper, we single out the following particular case of the clique search problem. The vertices of the given graph are legally colored with k colors and we are looking for a clique with k nodes in the graph. In other words, we want to decide if a given k-partite graph contains a clique with k nodes. The maximum clique problem asks for finding a maximum clique in a given finite simple graph. The problem of deciding if the given graph contains a clique with k vertices is called the k-clique problem. The first problem is NP-hard and the second one is NP-complete. The special clique search problem, we propose, is still an NP-complete problem. We will show that the k-clique problem in the special case of k-partite graphs is more tractable than in the general case. In order to illustrate the possible practical utility of this restricted type clique search problem we will show that the job shop scheduling problem can be reduced to such a clique search problem in a suitable constructed graph. We carry out numerical experiments to assess the efficiency of the approach. It is a common practice that before one embarks on a large scale clique search typically one attempts to simplify and tidy up the given graph. This procedure is commonly referred as preconditioning or kernelization of the given graph. Of course, the preconditioning or kernelization is meant with respect to the given type of clique search problem. The other main topic of the paper is to describe a number of kernelization methods tailored particularly to the proposed special k-clique problem. Some of these techniques works in connection with the generic k-clique problem. In these situations, we will see that they are more efficient in the case of k-partite graphs. Some other preconditioning methods applicable only to k-partite graphs. We illustrate how expedient these preconditioning methods can be by solving non-trivial scheduling problems to optimality employing only kernelization techniques dispensing with exhaustive clique search algorithms altogether.
Effect of Slow–Fast Time Scale on Transient Dynamics in a Realistic Prey-Predator System
Authors: Chowdhury Pranali Roy , Petrovskii Sergei , Banerjee Malay
Published: February 2022

Systems with multiple time scales, often referred to as `slow–fast systems’, have been a focus of research for about three decades. Such systems show a variety of interesting, sometimes counter-intuitive dynamical behaviors and are believed to, in many cases, provide a more realistic description of ecological dynamics. In particular, the presence of slow–fast time scales is known to be one of the main mechanisms resulting in long transients—dynamical behavior that mimics a system’s asymptotic regime but only lasts for a finite (albeit very long) time. A prey–predator system where the prey growth rate is much larger than that of the predator is a paradigmatic example of slow–fast systems. In this paper, we provide detailed investigation of a more advanced variant of prey–predator system that has been overlooked in previous studies, that is, where the predator response is ratio-dependent and the predator mortality is nonlinear. We perform a comprehensive analytical study of this system to reveal a sequence of bifurcations that are responsible for the change in the system dynamics from a simple steady state and/or a limit cycle to canards and relaxation oscillations. We then consider how those changes in the system dynamics affect the properties of long transient dynamics. We conclude with a discussion of the ecological implications of our findings, in particular to argue that the changes in the system dynamics in response to an increase of the time scale ratio are counter-intuitive or even paradoxical.
What Group Theory Can Do for You: From Magmas to Abstract Thinking in School Mathematics
Authors: Veith Joaquin Marc , Bitzenbauer Philipp
Published: February 2022

In this paper, we present a novel concept for an abstract algebra course at the secondary school level. Against the backdrop of findings from mathematics education research, we discuss benefits that arise from teaching abstract algebra to secondary school students. We derive suitable content items as well as educational ideas on how to implement them into mathematics classrooms. We build on frameworks from mathematics education research to design a teaching-learning sequence that enables a beneficial learning trajectory across three units—the result is a coherent teaching concept that encompasses Magmas in a hands-on way. It can be used for either extra-curricular activities or advanced courses in mathematics classes, and can be of benefit for mathematics learners.
A Nonparametric Approach for Testing Long Memory in Stock Returns’ Higher Moments
Authors: Giacalone Massimiliano , Panarello Demetrio
Published: February 2022

In this paper, by considering a model-based approach for conditional moment estimation, a nonparametric test was performed to study the long-memory property of higher moments. We considered the daily returns of the stocks included in the S&P500 index in the last ten years (for the period running from the 1st of January 2011 to the 1st of January 2021). We found that mean and skewness were characterized by short memory, while variance and shape had long memory. These results have deep implications in terms of asset allocation, option pricing and market efficiency evaluation.
Online Frequency Estimation on a Building-like Structure Using a Nonlinear Flexible Dynamic Vibration Absorber
Authors: Beltran-Carbajal Francisco , Abundis-Fong Hugo Francisco , Trujillo-Franco Luis Gerardo , Yañez-Badillo Hugo , Favela-Contreras Antonio , Campos-Mercado Eduardo
Published: February 2022

The online frequency estimation of forced harmonic vibrations on a building-like structure, using a nonlinear flexible vibration absorber in a cantilever beam configuration, is addressed in this article. Algebraic formulae to compute online the harmonic excitation frequency on the nonlinear vibrating mechanical system using solely available measurement signals of position, velocity, or acceleration are presented. Fast algebraic frequency estimation can, thus, be implemented to tune online a semi-active dynamic vibration absorber to obtain a high attenuation level of undesirable vibrations affecting the main mechanical system. A semi-active vibration absorber can be tuned for application where variations of the excitation frequency can be expected. Adaptive vibration absorption for forced harmonic vibration suppression for operational scenarios with variable excitation frequency can be then performed. Analytical, numerical, and experimental results to demonstrate the effectiveness and efficiency of the operating frequency estimation, as well as the acceptable attenuation level achieved by the tunable flexible vibration absorber, are presented. The algebraic parametric estimation approach can be extended to add capabilities of variable frequency vibration suppression for several configurations of dynamic vibration absorbers.
The Impact of the COVID-19 Pandemic on the Organization of Cardio-Hematology Care—A Polish Single Center Experience
Authors: Gościniak Piotr , Baumert Bartłomiej , Milczarek Sławomir , Jędrzychowska-Baraniak Joanna , Sobuś Anna , Machaliński Bogusław
Published: February 2022

Background and Objectives: We present a retrospective report on the cardio-hematological care of hematology patients at a university hospital in Poland during the COVID-19 pandemic. Materials and Methods: The number of hospitalizations at the Hematology Department and cardio-hematology consultations throughout 2019 and 2020 was analyzed. The types of cardiac procedures, risk factors, and complications were also assessed. Results: A significant reduction in the number of hospitalizations was observed in 2020 as compared to 2019. However, there were no significant differences in the incidence of hematological diseases between both of the analyzed years. In 2019, 299 cardiac consultations were performed in hematological patients, and there was a total of 352 such consultations performed in 2020 (p = 0.042). Less high-risk tests (transesophageal and stress echocardiography) were performed in 2020, in favor of the use of cardiac computed tomography in cardiac diagnostics as it was safer during the pandemic. At least one cardiovascular risk factor during cardiac consultation was noted in 42% and 48% of hematological patients in 2019 and 2020, respectively. Among 651 examined hematological patients, the most common findings were mild cardiac complications of hemato-oncological treatment, which were found in 57 patients. Conclusions: This study seems to confirm that during a pandemic there is an increased demand for well-organized cardio-hematology consultations.