bluuebunny/crossref_metadata_2025 huggingface dataset:
Dihydroartemisinin Inhibits mTORC1 Signaling by Activating the AMPK Pathway in Rhabdomyosarcoma Tumor Cells
Authors: Luo Jun , Odaka Yoshinobu , Huang Zhu , Cheng Bing , Liu Wang , Li Lin , Shang Chaowei , Zhang Chao , Wu Yang , Luo Yan , Yang Shengyong , Houghton Peter J. , Guo Xiaofeng , Huang Shile
Published: June 2021

Dihydroartemisinin (DHA), an anti-malarial drug, has been shown to possess potent anticancer activity, partly by inhibiting the mammalian target of rapamycin (mTOR) complex 1 (mTORC1) signaling. However, how DHA inhibits mTORC1 is still unknown. Here, using rhabdomyosarcoma (RMS) as a model, we found that DHA reduced cell proliferation and viability in RMS cells, but not those in normal cells, which was associated with inhibition of mTORC1. Mechanistically, DHA did not bind to mTOR or FK506 binding protein 12 (FKBP12). In addition, DHA neither inhibited insulin-like growth factor-1 receptor (IGF-1R), phosphoinositide 3-kinase (PI3K), and extracellular signal-regulated kinase ½ (Erk1/2), nor activated phosphatase and tensin homolog (PTEN) in the cells. Rather, DHA activated AMP-activated protein kinase (AMPK). Pharmacological inhibition of AMPK, ectopic expression dominant negative or kinase-dead AMPK, or knockdown of AMPKa attenuated the inhibitory effect of DHA on mTORC1 in the cells. Additionally, DHA was able to induce dissociation of regulatory-associated protein of mTOR (raptor) from mTOR and inhibit mTORC1 activity. Moreover, treatment with artesunate, a prodrug of DHA, dose-dependently inhibited tumor growth and concurrently activated AMPK and suppressed mTORC1 in RMS xenografts. The results indicated that DHA inhibits mTORC1 by activating AMPK in tumor cells. Our finding supports that DHA or artesunate has a great potential to be repositioned for treatment of RMS.
Redox Homeostasis in Muscular Dystrophies
Authors: Mosca Nicola , Petrillo Sara , Bortolani Sara , Monforte Mauro , Ricci Enzo , Piemonte Fiorella , Tasca Giorgio
Published: June 2021

In recent years, growing evidence has suggested a prominent role of oxidative stress in the pathophysiology of several early- and adult-onset muscle disorders, although effective antioxidant treatments are still lacking. Oxidative stress causes cell damage by affecting protein function, membrane structure, lipid metabolism, and DNA integrity, thus interfering with skeletal muscle homeostasis and functionality. Some features related to oxidative stress, such as chronic inflammation, defective regeneration, and mitochondrial damage are shared among most muscular dystrophies, and Nrf2 has been shown to be a central player in antagonizing redox imbalance in several of these disorders. However, the exact mechanisms leading to overproduction of reactive oxygen species and deregulation in the cellular antioxidants system seem to be, to a large extent, disease-specific, and the clarification of these mechanisms in vivo in humans is the cornerstone for the development of targeted antioxidant therapies, which will require testing in appropriately designed clinical trials.
Dopamine Neuron Diversity: Recent Advances and Current Challenges in Human Stem Cell Models and Single Cell Sequencing
Authors: Fiorenzano Alessandro , Sozzi Edoardo , Parmar Malin , Storm Petter
Published: June 2021

Human midbrain dopamine (DA) neurons are a heterogeneous group of cells that share a common neurotransmitter phenotype and are in close anatomical proximity but display different functions, sensitivity to degeneration, and axonal innervation targets. The A9 DA neuron subtype controls motor function and is primarily degenerated in Parkinson’s disease (PD), whereas A10 neurons are largely unaffected by the condition, and their dysfunction is associated with neuropsychiatric disorders. Currently, DA neurons can only be reliably classified on the basis of topographical features, including anatomical location in the midbrain and projection targets in the forebrain. No systematic molecular classification at the genome-wide level has been proposed to date. Although many years of scientific efforts in embryonic and adult mouse brain have positioned us to better understand the complexity of DA neuron biology, many biological phenomena specific to humans are not amenable to being reproduced in animal models. The establishment of human cell-based systems combined with advanced computational single-cell transcriptomics holds great promise for decoding the mechanisms underlying maturation and diversification of human DA neurons, and linking their molecular heterogeneity to functions in the midbrain. Human pluripotent stem cells have emerged as a useful tool to recapitulate key molecular features of mature DA neuron subtypes. Here, we review some of the most recent advances and discuss the current challenges in using stem cells, to model human DA biology. We also describe how single cell RNA sequencing may provide key insights into the molecular programs driving DA progenitor specification into mature DA neuron subtypes. Exploiting the state-of-the-art approaches will lead to a better understanding of stem cell-derived DA neurons and their use in disease modeling and regenerative medicine.
Global Mapping of Indigenous Resilience Facing the Challenge of the COVID-19 Pandemic
Authors: Lugo-Morin Diosey Ramon
Published: June 2021

Indigenous social development scenarios must be understood as the possibility of improving the sustainability of the planet and human health in the face of the COVID-19 pandemic. Integrating the institutional resilience approach by learning from the experience of indigenous peoples’ informal institutions through the design of public policies can be a reality. To demonstrate the potential of this premise, a case study was conducted that examined the institutional resilience of one indigenous people, whose findings under nomothetic conditions may be useful for other territories around the world. These peoples provide lessons on how they cope with adversity, the COVID-19 pandemic being one of them. Institutional resilience is a step towards reaching out to the world’s ancestral populations to learn from their knowledge. These scenarios can help us understand the implications of international policies on the capacities of nations to secure access to food and resources and, subsequently, to be better prepared for future pandemics.
The Effect of Short-Term Wingate-Based High Intensity Interval Training on Anaerobic Power and Isokinetic Muscle Function in Adolescent Badminton Players
Authors: Ko Duk-Han , Choi Yong-Chul , Lee Dong-Soo
Published: May 2021

Badminton requires both aerobic fitness and anaerobic ability for high performance. High intensity interval training (HIIT) is a traditional training method for improving fitness. In this study, we investigated whether short-term Wingate-based HIIT is effective for improving anaerobic activity in youth badminton players. Participants included 32 total badminton players in middle school and high school. They were divided into two groups (HIIT and moderate continuous training (MCT)). Training occurred for 4 weeks in total, three times a week, for 30 min each session. A body composition test, isokinetic knee muscle function test (60°/s, 240°/s), Wingate anaerobic power test (30 s × 5 sets), and analysis of heart rate changes were undertaken before and after training. After 4 weeks, body fat decreased in the HIIT group (p = 0.019); they also showed superior anaerobic ability compared to the MCT group. Differences were statistically significant in 3–4 sets (three sets, p = 0.019; four sets, p = 0.021). Regarding fatigue, the HIIT group showed superior fatigue improvement after training and better fatigue recovery ability in 3~5 sets (three sets, p = 0.032; four sets, p = 0.017; five sets, p = 0.003) than the MCT group. Neither group exhibited changes in heart rate during the anaerobic power test after training. Both groups improved in terms of isokinetic knee muscle function at 60°/s with no differences. However, at 240°/s, the HIIT group showed a statistically significant improvement (p = 0.035). Therefore, HIIT for 4 weeks improved the athletes’ performance and physical strength.
Pulsed Laser Deposition of Epitaxial Non-Doped PbTiO3 Thin Films from PbO–TiO2 Mosaic Targets
Authors: Sakai Joe , Roque José Manuel Caicedo , Vales-Castro Pablo , Padilla-Pantoja Jessica , Sauthier Guillaume , Santiso José
Published: June 2021

PbTiO3 (PTO) suffers from difficulty in preparing high-density robust bulk ceramics, which in turn has been a bottleneck in thin films growth with physical vapor deposition (PVD) methods. In the present work, we prepared non-doped PTO thin films by a pulsed laser deposition (PLD) method with either a single PTO target or a mosaic target consisting of PbO and TiO2 pie-shaped pieces. On the PTO single target, laser irradiation caused selective ablation of Pb, resulting in Ti-rich cone-shaped pillar structure on the surface, whereas the irradiated surface of PbO and TiO2 pieces was smoother. Epitaxial PTO films deposited on SrTiO3 (001) substrates from the pie-chart targets with PbO:TiO2 areal ratio from 3:5 to 5:3 resulted in composition, crystallinity, flatness, and ferroelectric properties almost independent of the areal ratio. The averaged composition of each film was close to stoichiometric, suggesting a compositional self-control mechanism. For growing epitaxial and high-quality non-doped PTO films, a PbO–TiO2 pie-chart target is advantageous in easiness of handling and stable surface structure.
Effects of Polysilane Addition to Chlorobenzene and High Temperature Annealing on CH3NH3PbI3 Perovskite Photovoltaic Devices
Authors: Oku Takeo , Taguchi Masaya , Suzuki Atsushi , Kitagawa Kaede , Asakawa Yugo , Yoshida Satoshi , Okita Masanobu , Minami Satoshi , Fukunishi Sakiko , Tachikawa Tomoharu
Published: June 2021

CH3NH3PbI3 perovskite photovoltaic devices treated with a polysilane layer were fabricated and characterized. Decaphenylcyclopentasilane (DPPS) in chlorobenzene solution was deposited at the surface of the perovskite layer, and the resulting device was annealed at 140–260 °C. The photoconversion efficiencies of the DPPS-treated device remained high even after 255 days in ambient air. Raman scattering spectroscopy and ab initio molecular orbital calculations of DPPS suggested that it increased hole transport efficiency in the treated devices, which was confirmed from the high shunt resistances of the DPPS-treated devices.
Preparation and Degradation Characteristics of MAO/APS Composite Bio-Coating in Simulated Body Fluid
Authors: Wang Zexin , Ye Fei , Chen Liangyu , Lv Weigang , Zhang Zhengyi , Zang Qianhao , Peng Jinhua , Sun Lei , Lu Sheng
Published: June 2021

In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.
Toward Bactericidal Enhancement of Additively Manufactured Titanium Implants
Authors: Fang Yingjing , Attarilar Shokouh , Yang Zhi , Wei Guijiang , Fu Yuanfei , Wang Liqiang
Published: June 2021

Implant-associated infections (IAIs) are among the most intractable and costly complications in implant surgery. They can lead to surgery failure, a high economic burden, and a decrease in patient quality of life. This manuscript is devoted to introducing current antimicrobial strategies for additively manufactured (AM) titanium (Ti) implants and fostering a better understanding in order to pave the way for potential modern high-throughput technologies. Most bactericidal strategies rely on implant structure design and surface modification. By means of rational structural design, the performance of AM Ti implants can be improved by maintaining a favorable balance between the mechanical, osteogenic, and antibacterial properties. This subject becomes even more important when working with complex geometries; therefore, it is necessary to select appropriate surface modification techniques, including both topological and chemical modification. Antibacterial active metal and antibiotic coatings are among the most commonly used chemical modifications in AM Ti implants. These surface modifications can successfully inhibit bacterial adhesion and biofilm formation, and bacterial apoptosis, leading to improved antibacterial properties. As a result of certain issues such as drug resistance and cytotoxicity, the development of novel and alternative antimicrobial strategies is urgently required. In this regard, the present review paper provides insights into the enhancement of bactericidal properties in AM Ti implants.
Mitigation of Platinum Depletion in Platinum Diffused Single Phase Bond Coat on CMSX-4 Superalloy
Authors: Bai Mingwen , Chen Ying , Sun Yongle , Xiao Ping
Published: June 2021

Pt-diffused bond coat with a mixture of γ/γ’ phase has just been developed in the recent decades as a cheaper alternative to the Pt-enriched β-phase Aluminide bond coat that contains a higher content of Al. However, concerns are raised on the inevitable depletion of Pt near the coating interface that may endanger the component after long-term service. In this study, modified Pt-diffused bond coats with a single phase (γ or γ’) were made by applying selective etching on CMSX-4 single crystal superalloys prior to the electroplating of Pt. The single-phase bond coats show distinctive diffusion behaviour in comparison with the conventional γ/γ’ bond coat. Surprisingly, Pt remains more stable in the γ’-phase bond coat with significantly less depletion after diffusion, which implies a potential in saving a considerable amount of Pt. On the other hand, however, the depletion of Pt is more severe in the γ-phase bond coat. The mechanism that governs the diffusion behavior of Pt in the γ and γ’-phase was also discussed that mainly concerns with thermodynamic and kinetic factors.
The Effect of Polytetrafluoroethylene (PTFE) Particles on Microstructural and Tribological Properties of Electroless Ni-P+PTFE Duplex Coatings Developed for Geothermal Applications
Authors: Oppong Boakye Gifty , Ormsdóttir Arna María , Gunnarsson Baldur Geir , Irukuvarghula Sandeep , Khan Raja , Karlsdóttir Sigrún Nanna
Published: June 2021

The selection of electroless nickel-phosphorus plating (ENP) has been inclined towards their properties and advantages with complex geometry applications. These properties include coating uniformity, low surface roughness, low wettability, high hardness, lubricity, and corrosion- and wear-resistance. Materials used in geothermal environments are exposed to harsh conditions such as high loads, temperature, and corrosive fluids, causing corrosion, scaling, erosion and wear of components. To improve the corrosion- and wear-resistance and anti-scaling properties of materials for geothermal environment, a ENP duplex coating with PTFE nanoparticles was developed and deposited on mild steel within the H2020 EU Geo-Coat project. ENP thin adhesive layer and ENP+PTFE top functional layer form the duplex structure of the coating. The objective of this study was to test the mechanical and tribological properties of the developed ENP-PTFE coatings with varying PTFE content. The microstructural, mechanical and tribological properties of the as-deposited coating with increasing PTFE content in the top functional layer in the order: ENP1, ENP2 and ENP3 were evaluated. The results showed maximum wear protection of the substrates at the lowest load; however, increasing load and sliding cycles increased the wear rates, and 79% increased lubrication was recorded for the ENP2 duplex coating. The wear performance of ENP3 greatly improved with a wear resistance of 8.3 × 104 m/mm3 compared to 6.9 × 104 m/mm3 for ENP2 and 2.1 × 104 m/mm3 for ENP1. The results are applicable in developing low friction, hydrophobic or wear-resistive surfaces for geothermal application.
Preparation of Nanochitin/Polystyrene Composite Particles by Pickering Emulsion Polymerization Using Scaled-Down Chitin Nanofibers
Authors: Watanabe Ryuta , Izaki Kakeru , Yamamoto Kazuya , Kadokawa Jun-ichi
Published: June 2021

In this study, we investigate the Pickering emulsion polymerization of styrene using scaled-down chitin nanofibers (SD-ChNFs) as stabilizers to produce nanochitin/polystyrene composite particles. Prior to emulsion polymerization, an SD-ChNF aqueous dispersion was prepared by disintegrating bundles of the parent ChNFs with an upper hierarchical scale in aqueous acetic acid through ultrasonication. After styrene was added to the resulting dispersions, the mixtures at the desired weight ratios (SD-ChNFs to styrene = 0.1:1–1.4:1) were ultrasonicated to produce Pickering emulsions. Radical polymerization was then conducted in the presence of potassium persulfate as an initiator in the resulting emulsions to fabricate the composite particles. The results show that their average diameters decreased to a minimum of 84 nm as the weight ratios of SD-ChNFs to styrene increased. The IR and 1H-NMR spectra of the composite particle supported the presence of both chitin and polystyrene in the material.
Experimental Study Regarding the Possibility of Blocking the Diffusion of Sulfur at Casting-Mold Interface in Ductile Iron Castings
Authors: Anca Denisa , Stan Iuliana , Chisamera Mihai , Riposan Iulian , Stan Stelian
Published: June 2021

The main objective of this work is to investigate the mechanism of sulfur diffusion from the mold (sand resin P-toluol sulfonic acid mold, sulfur-containing acid) in liquid cast iron in order to limit the graphite degeneration in the surface layer of iron castings. A pyramid trunk with square section samples was cast. On the opposite side of the feed canal of the samples, steel sheets with different thicknesses (0.5, 1, and 3 mm) were inserted with the intention of blocking the diffusion of sulfur from the mold into the cast sample during solidification. The structure evaluation (graphite and matrix) in the surface layer and the casting body was recorded. The experimental results revealed that by blocking the direct diffusion of sulfur at the mold-casting interface, a decrease of the demodified layer thickness (for 0.5 mm steel sheet thickness) is obtained until its disappearance (for steel sheet thicknesses of more than 1 mm). The paper contains data that may be useful in elucidating the mechanism of graphite degeneration in the superficial layer of ductile iron castings. Based on the obtained results, we recommend using such barriers on the metal-mold interface, which are able to limit sulfur diffusion from the mold/core materials into the iron castings, in order to limit or even cease graphite degeneration in the Mg-treated surface iron casting layer. The paper presents additional data related to the interaction of sulfur at the ductile iron casting-mold interface previously analyzed.
Computational Performance of Disparate Lattice Boltzmann Scenarios under Unsteady Thermal Convection Flow and Heat Transfer Simulation
Authors: Hartono Aditya Dewanto , Sasaki Kyuro , Sugai Yuichi , Nguele Ronald
Published: June 2021

The present work highlights the capacity of disparate lattice Boltzmann strategies in simulating natural convection and heat transfer phenomena during the unsteady period of the flow. Within the framework of Bhatnagar-Gross-Krook collision operator, diverse lattice Boltzmann schemes emerged from two different embodiments of discrete Boltzmann expression and three distinct forcing models. Subsequently, computational performance of disparate lattice Boltzmann strategies was tested upon two different thermo-hydrodynamics configurations, namely the natural convection in a differentially-heated cavity and the Rayleigh-Bènard convection. For the purposes of exhibition and validation, the steady-state conditions of both physical systems were compared with the established numerical results from the classical computational techniques. Excellent agreements were observed for both thermo-hydrodynamics cases. Numerical results of both physical systems demonstrate the existence of considerable discrepancy in the computational characteristics of different lattice Boltzmann strategies during the unsteady period of the simulation. The corresponding disparity diminished gradually as the simulation proceeded towards a steady-state condition, where the computational profiles became almost equivalent. Variation in the discrete lattice Boltzmann expressions was identified as the primary factor that engenders the prevailed heterogeneity in the computational behaviour. Meanwhile, the contribution of distinct forcing models to the emergence of such diversity was found to be inconsequential. The findings of the present study contribute to the ventures to alleviate contemporary issues regarding proper selection of lattice Boltzmann schemes in modelling fluid flow and heat transfer phenomena.
Efficacy of a Polyphenolic, Standardized Green Tea Extract for the Treatment of COVID-19 Syndrome: A Proof-of-Principle Study
Authors: Bettuzzi Saverio , Gabba Luigi , Cataldo Simona
Published: June 2021

The lack of therapies for moderate COVID-19 syndrome prompted us to use a standardized polyphenolic green tea extract rich in catechins during the lockdown due to the pandemic in Italy (Autumn 2020). Catechins are powerful antioxidant, anti-inflammatory and antiviral agents that are safe for human use. While awaiting hospitalization, 10 swab-positive patients, symptomatic for SARS-COV-2, were treated for 15 days at home with two sessions of inhalation plus three capsules per day (total catechins: 840 mg; total EGCG: 595 mg). All patients recovered fully and had no symptoms at a median of 9 days, with a range of 7–15 days. Seven switched to a negative SARS-COV-2 nasopharyngeal swab test at a median of 9 days, with a range of 6–13 days. Among the 3 patients still swab-positive, one had a strong decrease of infection down to a “very low” SARS-COV-2 nucleic acid load at 5 days. All patients exited quarantine at the end of therapy because they were free of symptoms. Inflammation markers α-1 anti-trypsin, C-reactive protein and eosinophils had significantly decreased. The IL-6 and erythrocyte sedimentation rate decreased in 7 out of 10 patients. To the best of our knowledge, this is the first report of the efficacy of green tea catechin against COVID-19 syndrome. These results may open new perspectives in the fight against the disease.
Core-Shell Structure and Dielectric Properties of Ba0.6Sr0.4TiO3@ Fe2O3 Ceramics Prepared by Co-Precipitation Method
Authors: Li Zhuo , Wang Chenbo , Wang Zixuan , Zhang Dandan , Qin Yangxiao , Yang Qiangbin , Wang Zhuo , Zhao Peng , Ma Xinshuai , Li Minghan , Ai Tao , Yan Xin , Niu Yanhui , Peng Biaolin , Sun Shikuan , Wang Dawei
Published: June 2021

Ba0.6Sr0.4TiO3 (BST) ceramic materials have been widely used in the field of multilayer ceramic capacitors. Surface modification through the surface coating to form a heterogeneous layer could effectively improve the dielectric properties. In this work, BST powders were prepared by a co-precipitation method. The effects of reaction conditions on the microstructure of the BST powder were investigated. The reaction temperatures significantly affected the morphology of BST powder, and the rhombic-type particles were obtained with the reaction temperature around 80 °C. Meanwhile, the BST@Fe2O3 was prepared by the chemical precipitation method using BST powders with rhombic-type microstructure as “core”, and the so-called “core-shell” microstructure was confirmed in the BST@Fe2O3 powder. Then, BST@x wt%Fe2O3 (x = 2.5, 5, 7.5, and 10, denoting the different content of Fe2O3) ceramics were further prepared, and the influence of “core-shell” structure on the phase structure, microstructure, and dielectric properties was investigated. With the increasing of Fe2O3 content, the ferroelectric–paraelectric phase transition temperature shifts toward lower temperatures, and dielectric peaks gradually become broad and frequency-dependent, which may be due to inconsistent chemical composition from core to shell.
La1–yBayF3–y Solid Solution Crystals as an Effective Solid Electrolyte: Growth and Properties
Authors: Buchinskaya Irina I. , Karimov Denis N. , Sorokin Nikolay I.
Published: June 2021

A series of nonstoichiometric La1–yBayF3–y (0 ≤ y ≤ 0.12) single crystals with a tysonite-type structure (sp. gr. P-3c1) was grown from the melt by the directional crystallization method in a fluorinating atmosphere, and some physical properties were characterized. The concentration dependence of electrical conductivity σdc(y) La1–yBayF3–y crystals was studied. The composition of the ionic conductivity maximum for this solid electrolyte was refined. It was confirmed that the maximum conductivity σmax = 8.5 × 10–5 S/cm (295 K) was observed at the composition ymax = 0.05 ± 0.01. Analysis of the electrophysical data for the group of tysonite-type solid electrolytes R1–yMyF3–y (M = Ca, Sr, Ba, Eu2+ and R = La, Ce, Pr, Nd) showed that the compositions of the maxima of their conductivity were close and amount to y = 0.03−0.05. This fact indicates a weak influence of the size effect (ionic radii R3+ and M2+) on the value of ymax for R1–yMyF3–y solid electrolytes.
Embedded Silicon Nanoparticles as Enabler of a Novel CMOS-Compatible Fully Integrated Silicon Photonics Platform
Authors: González-Fernández Alfredo A. , Aceves-Mijares Mariano , Pérez-Díaz Oscar , Hernández-Betanzos Joaquin , Domínguez Carlos
Published: June 2021

The historical bottleneck for truly high scale integrated photonics is the light emitter. The lack of monolithically integrable light sources increases costs and reduces scalability. Quantum phenomena found in embedded Si particles in the nanometer scale is a way of overcoming the limitations for bulk Si to emit light. Integrable light sources based in Si nanoparticles can be obtained by different CMOS (Complementary Metal Oxide Semiconductor) -compatible materials and techniques. Such materials in combination with Si3N4 photonic elements allow for integrated Si photonics, in which photodetectors can also be included directly in standard Si wafers, taking advantage of the emission in the visible range by the embedded Si nanocrystals/nanoparticles. We present the advances and perspectives on seamless monolithic integration of CMOS-compatible visible light emitters, photonic elements, and photodetectors, which are shown to be viable and promising well within the technological limits imposed by standard fabrication methods.
Freeze-Up Ice Jam Formation in the River Bend, a Case Study on the Inner Mongolia Reach of Yellow River
Authors: Zhao Shui-Xia , Wang Wen-Jun , Shi Xiao-Hong , Zhao Sheng-Nan , Wu Ying-Jie , Quan Qiang , Li Chao , Szydlowski Michal , Li Wei , Kolerski Tomasz
Published: June 2021

Concern has been expressed regarding the impacts of climate change on river ice and ice jam formation in cold regions. Ice jams are easily initiated in bends and narrow channels and cause disasters. In this study, observations and remote sensing monitoring are used to study the freeze-up ice jam formation of bends. Sediment transport and freezing process of the river interact, influencing bed changes profile and sedimentary budget. River ice processes, channel evolution, ice hydro-thermodynamics, and ice jam accumulation are explored. The results show that the channel topography determines the river thalweg, and that the channel elevation interacts with the river ice through sediment transport. The channel shrinkage increases the probability of ice jam, and the sharp bend is prone to ice jam formation. Under the effect of secondary circulation flow in the bend and in the outer bank, the juxtaposed freeze-up and the hummocky ice cover occur in the same location, and frazil ice accumulates under the junction of the main channel and the shoals. Affected by the increase of the hydraulic slope and the velocity downstream, open water reaches develops downstream of the ice accumulation. An open water section is emerged upstream of the bend, due to the ice deposition, and partly cut-off supply of the frazil.
Performance Evaluation of Cementitious Composites Containing Granulated Rubber Wastes, Silica Fume, and Blast Furnace Slag
Authors: Tagba Maléki , Li Shujin , Jiang Mingjie , Gao Xu , Benmalek Mohamed Larbi , Boukour Salima , Liu Chuanqi
Published: June 2021

In this study, rubberized cementitious materials are produced with recycled rubber waste as an alternative to fine aggregate. Mixtures with different additions to rubber wastes (RW), silica fume (SF), and blast furnace slag (BFS) have been designed and characterized. Hardened properties including compressive and bond strength, shrinkage, water-accessible porosity, rapid chloride migration, and microstructure were investigated. The results show that the addition of SF and BFS improves the performances of rubberized mortars and reduces shrinkage. The incorporation of 5% RW with 20% BFS increases compressive strength and reduces water-accessible porosity. Ion chloride resistance was enhanced by a combination of 15% RW, 8% SF, and 20% BFS. The addition of SF and BFS as cement replacement improves the performance of mortars due to their filling effect and a pozzolanic reaction, which has been verified by a microstructural analysis.
Recent Advances on Properties and Utility of Nanomaterials Generated from Industrial and Biological Activities
Authors: Yadav Virendra Kumar , Malik Parth , Khan Afzal Husain , Pandit Priti Raj , Hasan Mohd Abul , Cabral-Pinto Marina M. S. , Islam Saiful , Suriyaprabha R. , Yadav Krishna Kumar , Dinis Pedro A. , Khan Samreen Heena , Diniz Luisa
Published: June 2021

Today is the era of nanoscience and nanotechnology, which find applications in the field of medicine, electronics, and environmental remediation. Even though nanotechnology is in its emerging phase, it continues to provide solutions to numerous challenges. Nanotechnology and nanoparticles are found to be very effective because of their unique chemical and physical properties and high surface area, but their high cost is one of the major hurdles to its wider application. So, the synthesis of nanomaterials, especially 2D nanomaterials from industrial, agricultural, and other biological activities, could provide a cost-effective technique. The nanomaterials synthesized from such waste not only minimize pollution, but also provide an eco-friendly approach towards the utilization of the waste. In the present review work, emphasis has been given to the types of nanomaterials, different methods for the synthesis of 2D nanomaterials from the waste generated from industries, agriculture, and their application in electronics, medicine, and catalysis.
Preparation of Magnesia Partially Stabilized Zirconia Nanomaterials from Zirconium Hydroxide and Magnesium Carbonate Precursors Using PEG as a Template
Authors: Wijayanti Rizky , Rosmayanti Irna , Wahyudi Kristanto , Maryani Eneng , Hernawan Hernawan , Septawendar Rifki
Published: June 2021

Stabilized zirconia is a promising material due to its great physical and chemical properties, and thermal stability. In this work, MgO was used as a stabilizer in ZrO2 to obtain Magnesia Partially Stabilized Zirconia (MSZ) nanomaterials assisted with PEG as a template through conventional mixing process. Zirconium hydroxides prepared from local zircon and MgCO3 were used as MSZ precursors. Meanwhile, the stabilizer concentration was varied from 1 to 4 wt% of ZrO2. The effect of the stabilizer concentration and the calcination temperature to the crystallinity and the morphological properties of the MSZ nanoparticles were studied using X-ray diffraction and scanning and transmission electron microscopy. The ZrO2 content in the zirconium hydroxides precursors is accounting 89.52 wt% of the total and exhibits the dominant m-phase at 1000 °C. Meanwhile, the tetragonal and the monoclinic phases were formed in all MSZ samples at a temperature of 800–1000 °C. The as-synthesized MSZ samples show typical FT-IR spectra, consisting of the metal–oxygen bonds at below 500 cm−1 and the organic functional groups ranging at 1000–3000 cm−1. The ZrO2 morphologies exhibit spherical-like shapes with elongated agglomeration at 800 °C. In addition, the average particle sizes of the final product ranges from 20 to 50 nm. At a sintering temperature of 1500 °C, MSZ samples show the monoclinic phase of ZrO2 and densities in the range of 3.95–4.14 g/cm3.
Observations on the Surface Structure of Aurelia solida (Scyphozoa) Polyps and Medusae
Authors: Turk Valentina , Fortič Ana , Kos Kramar Maja , Tušek Žnidarič Magda , Štrus Jasna , Kostanjšek Rok , Malej Alenka
Published: June 2021

The surface structures and mucus layers that form an interface between the epithelial layer of organisms and their external environment were studied in the bloom-forming moon jellyfish (Aurelia solida, Scyphozoa) from the northern Adriatic. The surface of the polyps revealed epithelial ciliated cells and numerous nematocysts, both non-discharged and discharged. Cilia were also the most prominent features on the surface of adult medusa, protruding from the epidermal cells and with microvilli surrounding the base. Histochemical methods and various microscopy techniques (light/epifluorescence and electron microscopy) confirmed the presence of abundant mucus around polyps and on the surfaces of adult medusa, and that the mucus contained acidic and neutral mucins. The observed mucus secretions on the exumbrella surface of the medusae were in the form of granules, flocs, and sheets. Scanning electron microscopy and transmission electron microscopy analyses confirmed the presence of various microbes in the mucus samples, but not on the epithelial surfaces of the polyps or the exumbrella of the medusae.
Sarcoid-Like Reaction in Non-Hodgkin’s Lymphoma—A Diagnostic Challenge for Deauville Scoring on 18F-FDG PET/CT Imaging
Authors: Winkelmann Michael , Rejeski Kai , Subklewe Marion , Ricke Jens , Unterrainer Marcus , Rudelius Martina , Kunz Wolfgang G.
Published: June 2021

The sarcoid-like reaction represents an autoinflammatory cause of mediastinal and hilar lymphadenopathy but may also involve other lymph node regions and organs. This rare phenomenon has mainly been reported in patients with Hodgkin’s lymphoma (HL) or solid tumors (particularly melanoma) undergoing immunotherapy and chemotherapy. Cases in non-Hodgkin’s lymphoma (NHL) are very uncommon. We present an uncommon case of a patient with primarily mediastinal diffuse large B-cell lymphoma (DLBCL) who showed a CT-based partial response in interim staging, whereas at end-of-treatment multiple newly enlarged and hypermetabolic mediastinal and bilateral hilar lymph nodes were detected by 18F-FDG PET/CT imaging. A subsequent histological workup determined a sarcoid-like reaction without any lymphomatous tissue. Therefore, sarcoid-like reactions should be considered as a potential pitfall in Deauville staging with 18F-FDG PET/CT imaging for patients with NHL.
Integration of Dental Implants in Conjunction with EDTA-Conditioned Dentin Grafts: An Experimental Study
Authors: Farzad Payam , Lundgren Ted , Al-Asfour Adel , Andersson Lars , Dahlin Christer
Published: June 2021

This study was undertaken to investigate the integration of titanium micro-implants installed in conjunction with previously dentin-grafted areas and to study the morphological appearance, mineral content, and healing pattern of xenogenic EDTA-conditioned dentin blocks and granules grafted to cavities in the tibial bone of rabbits. Demineralized and non-demineralized dentin blocks and granules from human premolars were implanted into cavities prepared on the lateral aspects of the tibias of rabbits. After a healing period of six months, micro-implants were installed at each surgical site. Histological examinations were carried out after 24 weeks. Characterization of the EDTA-conditioned dentin blocks was performed by means of light microscopy, dental X-rays, scanning electron microscopy, and energy dispersive X-ray analysis (EDX). No implants were found to be integrated in direct contact with the dentin particles or blocks. On the EDTA-conditioned dentin surface, the organic marker elements C and N dominated, as revealed by EDX. The hydroxyapatite constituents Ca and P were almost absent on the dentin surface. No statistically significant difference was observed between the EDTA-conditioned and non-demineralized dentin, as revealed by BIC and BA. The bone-inductive capacity of the dentin material seemed limited, although demineralization by means of EDTA indicated higher BIC and BA values in conjunction with the installed implants in the area. A 12 h EDTA treatment did not fully decalcify the grafts, as revealed by X-ray analysis.
Knowledge Discovery from Medical Data and Development of an Expert System in Immunology
Authors: Pac Małgorzata , Mikutskaya Irina , Mulawka Jan
Published: June 2021

Artificial intelligence is one of the fastest-developing areas of science that covers a remarkably wide range of problems to be solved. It has found practical application in many areas of human activity, also in medicine. One of the directions of cooperation between computer science and medicine is to assist in diagnosing and proposing treatment methods with the use of IT tools. This study is the result of collaboration with the Children’s Memorial Health Institute in Warsaw, from where a database containing information about patients suffering from Bruton’s disease was made available. This is a rare disorder, difficult to detect in the first months of life. It is estimated that one in 70,000 to 90,000 children will develop Bruton’s disease. But even these few cases need detailed attention from doctors. Based on the data contained in the database, data mining was performed. During this process, knowledge was discovered that was presented in a way that is understandable to the user, in the form of decision trees. The best models obtained were used for the implementation of expert systems. Based on the data introduced by the user, the system conducts expertise and determines the severity of the course of the disease or the severity of the mutation. The CLIPS language was used for developing the expert system. Then, using this language, software was developed producing six expert systems. In the next step, experimental verification was performed, which confirmed the correctness of the developed systems.
Entrepreneurial Intention before and during COVID-19—A Case Study on Portuguese University Students
Authors: Lopes João M. , Gomes Sofia , Santos Tânia , Oliveira Márcio , Oliveira José
Published: June 2021

The present research aims to compare the entrepreneurial intention of university students before and during the Covid-19 pandemic. For this purpose, some dimensions were analyzed, such as the availability of this target audience to undertake an activity at their own risk, the preference for a future while employed by others, their perception of the values that society places on entrepreneurship, and the entrepreneurial abilities/skillsets. A comparative study of a quantitative nature was used, associating two samples composed of students of higher education in Portugal, the data were obtained before and during the COVID-19 pandemic. The analysis of the results permits us to conclude: (1) in the circumstances of macroeconomic changes resulting from the COVID-19 pandemic, entrepreneurial activity does not decrease; (2) respondents are less interested in being employed by others and more attracted to being entrepreneurs; (3) there is a growing concordance with the values that society places on entrepreneurship; and (4) there is now a greater aptitude for entrepreneurial activity. The present research is original, as it compares data obtained in different contexts of economic and social stability. It contributes to theory and practice, in the sense that it points to conclusions in the opposite direction of other studies carried out in situations of disasters of another nature, and can serve as a reference for the development of strategies to promote entrepreneurship, within higher education institutions and official entities to publicize and promote new public policies.
Beamforming Evaluation of 5G User Equipment through Novel Key Performance Indicators
Authors: García-Fernández Miguel Á. , Sánchez-Hernández David A.
Published: June 2021

Several standards exist for testing the radiated “over the air” (OTA) performance of 5G User Equipment (UE) devices. All these standards are limited to a Single-Input Single-Output (SISO) evaluation of the 5G device. With 5G networks and devices already deployed and in operation, it becomes necessary to develop realistic Multiple-Input Multiple-Output (MIMO) and beamforming performance metrics for 5G UEs. Since the most important feature of 5G is beamforming, this paper reviews the main challenges to realistically evaluate 5G device performance and proposes several novel key performance indicators (KPIs). The results obtained by some measurements show that it is possible to derive figures of merit that address the complexity of beamforming and MIMO-based 5G performance of devices in a much better way compared with the existing SISO KPIs, and that academia should provide advanced future research on these more realistic KPIs for the industry to face the challenges ahead with a better analysis of the problem in hand.
Transportation-Mission-Based Optimization of Heterogeneous Heavy-Vehicle Fleet Including Electrified Propulsion
Authors: Ghandriz Toheed , Jacobson Bengt , Islam Manjurul , Hellgren Jonas , Laine Leo
Published: June 2021

Commercial-vehicle manufacturers design vehicles to operate over a wide range of transportation tasks and driving cycles. However, certain possibilities of reducing emissions, manufacturing and operational costs from end vehicles are neglected if the target range of transportation tasks is narrow and known in advance, especially in case of electrified propulsion. Apart from real-time energy optimization, vehicle hardware can be meticulously tailored to best fit a known transportation task. As proposed in this study, a heterogeneous fleet of heavy-vehicles can be designed in a more cost- and energy-efficient manner, if the coupling between vehicle hardware, transportation mission, and infrastructure is considered during initial conceptual-design stages. To this end, a rather large optimization problem was defined and solved to minimize the total cost of fleet ownership in an integrated manner for a real-world case study. In the said case-study, design variables of optimization problem included mission, recharging infrastructure, loading–unloading scheme, number of vehicles of each type, number of trips, vehicle-loading capacity, selection between conventional, fully electric, and hybrid powertrains, size of internal-combustion engines and electric motors, number of axles being powered, and type and size of battery packs. This study demonstrated that by means of integrated fleet customization, battery-electric heavy-vehicles could strongly compete against their conventional combustion-powered counterparts. The primary focus has been put on optimizing vehicle propulsion, transport mission, infrastructure and fleet size rather than routing.
Optimization of Architectural Form for Thermal Comfort in Naturally Ventilated Gymnasium at Hot and Humid Climate by Orthogonal Experiment
Authors: Huang Xiaodan , Zhang Qingyuan , Tanaka Ineko
Published: June 2021

As the gymnasiums in subtropical region with hot and humid climate are naturally ventilated during non-competition periods, occupants exercising indoors often feel uncomfortable, especially in summer. In order to provide thermally comfortable and healthy environment for the occupants, the design on architectural form is found to be an effective solution on improving indoor thermal comfort of naturally ventilated gymnasiums. Therefore, a new perspective regarding optimization of naturally ventilated gymnasiums is proposed in the aspect of the architectural form. This paper presents the optimization of architectural form in naturally ventilated gymnasiums in which simulation and orthogonal experiment methods are combined. Through numerical simulation with FlowDesigner software, the significance of architectural form affecting indoor thermal comfort has been given, and the optimal architectural forms of naturally ventilated gymnasium are determined. The results show that the roof insulation type is the most significant factor influencing indoor thermal comfort; thus, it should be considered primarily in optimization. Moreover, the range analysis and variance analysis reveal the rankings of the factors for the gymnasium thermal comfort. In addition, it is demonstrated that the optimal gymnasium model, when compared with the initial gymnasium model, has a satisfactory effect on improving the indoor thermal comfort, as the average value of Predicted Thermal Sensation (PTS) in August decreased from 1.11 (Slightly hot) to 0.86 (Comfortable). This study provides a new insight for the designers in optimizing the architectural form of gymnasiums for achieving the indoor thermal comfort at hot and humid climate.
Comparison of Properties for Selected Experimental Set-Ups Dedicated to Measuring Thermal Parameters of Power LEDs
Authors: Górecki Krzysztof , Ptak Przemysław , Janicki Marcin , Napieralska Małgorzata
Published: June 2021

This article compares properties of two measurement set-ups dedicated to determining thermal parameters of power LEDs. The standard T3Ster set-up and the custom set-up developed in Gdynia Maritime University are considered. Both set-ups are described and the used measurement procedure is presented. The manner of measurement of optical power of the tested LEDs is also described. The method of measuring transfer transient thermal impedances between thermally coupled power LEDs using both set-ups is proposed. The measurement results of the mentioned parameters obtained with these set-ups for selected power LEDs are compared and discussed. Certain properties of software operating with both the considered measuring set-ups are also analyzed.
Pandemic Prevention: Lessons from COVID-19
Authors: Coccia Mario
Published: June 2021

Coronavirus disease 2019 (COVID-19) is caused by the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which appeared in late 2019, generating a pandemic crisis with high numbers of COVID-19-related infected individuals and deaths in manifold countries worldwide. Lessons learned from COVID-19 can be used to prevent pandemic threats by designing strategies to support different policy responses, not limited to the health system, directed to reduce the risks of the emergence of novel viral agents, the diffusion of infectious diseases and negative impact in society.