bluuebunny/crossref_metadata_2025 huggingface dataset:
Greener Nanocomposite Polyurethane Foam Based on Sustainable Polyol and Natural Fillers: Investigation of Chemico-Physical and Mechanical Properties
Authors: De Luca Bossa Ferdinando , Santillo Chiara , Verdolotti Letizia , Campaner Pietro , Minigher Andrea , Boggioni Laura , Losio Simona , Coccia Francesca , Iannace Salvatore , Lama Giuseppe C.
Published: January 2020

Nowadays, the chemical industry is looking for sustainable chemicals to synthesize nanocomposite bio-based polyurethane foams, PUs, with the aim to replace the conventional petrochemical precursors. Some possibilities to increase the environmental sustainability in the synthesis of nanocomposite PUs include the use of chemicals and additives derived from renewable sources (such as vegetable oils or biomass wastes), which comprise increasingly wider base raw materials. Generally, sustainable PUs exhibit chemico-physical, mechanical and functional properties, which are not comparable with those of PUs produced from petrochemical precursors. In order to enhance the performances, as well as the bio-based aspect, the addition in the polyurethane formulation of renewable or natural fillers can be considered. Among these, walnut shells and cellulose are very popular wood-based waste, and due to their chemical composition, carbohydrate, protein and/or fatty acid, can be used as reactive fillers in the synthesis of Pus. Diatomite, as a natural inorganic nanoporous filler, can also be evaluated to improve mechanical and thermal insulation properties of rigid PUs. In this respect, sustainable nanocomposite rigid PU foams are synthesized by using a cardanol-based Mannich polyol, MDI (Methylene diphenyl isocyanate) as an isocyanate source, catalysts and surfactant to regulate the polymerization and blowing reactions, H2O as a sustainable blowing agent and a suitable amount (5 wt%) of ultramilled walnut shell, cellulose and diatomite as filler. The effect of these fillers on the chemico-physical, morphological, mechanical and functional performances on PU foams has been analyzed.
Structure of Diamond Films Grown Using High-Speed Flow of a Thermally Activated CH4-H2 Gas Mixture
Authors: Fedoseeva Yu.V. , Gorodetskiy D.V. , Baskakova K.I. , Asanov I.P. , Bulusheva L.G. , Makarova A.A. , Yudin I.B. , Plotnikov M.Yu. , Emelyanov A.A. , Rebrov A.K. , Okotrub A.V.
Published: January 2020

Diamond films are advanced engineering materials for various industrial applications requiring a coating material with extremely high thermal conductivity and low electrical conductivity. An approach for the synthesis of diamond films via high-speed jet deposition of thermally activated gas has been applied. In this method, spatially separated high-speed flows of methane and hydrogen were thermally activated, and methyl and hydrogen radicals were deposited on heated molybdenum substrates. The morphology and structure of three diamond films were studied, which were synthesized at a heating power of 900, 1700, or 1800 W, methane flow rate of 10 or 30 sccm, hydrogen flow rate of 1500 or 3500 sccm, and duration of the synthesis from 1.5 to 3 h.The morphology and electronic state of the carbon on the surface and in the bulk of the obtained films were analyzed by scanning electron microscopy, Raman scattering, X-ray photoelectron, and near-edge X-ray absorption fine structure spectroscopies. The diamond micro-crystals with a thick oxidized amorphous sp2-carbon coating were grown at a heating power of 900 W and a hydrogen flow rate of 1500 sccm. The quality of the crystals was improved, and the growth rate of the diamond film was increased seven times when the heating power was 1700–1800 W and the methane and hydrogen flow rates were 30 and 3500 sccm, respectively. Defective octahedral diamond crystals of 30 μm in size with a thin sp2-carbon surface layer were synthesized on a Mo substrate heated at 1273 K for 1.5 h. When the synthesis duration was doubled, and the substrate temperature was decreased to 1073 K, the denser film with rhombic-dodecahedron diamond crystals was grown. In this case, the thinnest hydrogenated sp2-carbon coating was detected on the surface of the diamond crystals.
Anodic and Mechanical Behavior of Carbon Fiber Reinforced Polymer as a Dual-Functional Material in Chloride-Contaminated Concrete
Authors: Wei Liangliang , Zhu Ji-Hua , Dong Zhijun , Liu Jun , Liu Wei , Su Meini , Xing Feng
Published: January 2020

Carbon fiber reinforced polymer (CFRP) has been used as a dual-functional material in a hybrid intervention system (ICCP-SS) which integrates the impressed current cathodic protection (ICCP) and structural strengthening (SS). The mechanical behavior of CFRP as an anode has been investigated in some solution environments. However, the anodic and mechanical behavior of CFRP bonded to concrete is unclear. This paper focuses on the anodic and mechanical performance of CFRP bonded to the chloride-contaminated concrete by conducting an electrochemical (EC) test. The method of bonding the CFRP to the concrete and the shape of the steel embedded in the concrete were considered. The current densities of 20 mA/m2 and 100 mA/m2 were applied during 120-day and 310-day EC tests. The electrode potentials and driving voltages were recorded, and the bond interfaces of the CFRP were inspected after EC test. The residual tensile strength and failure modes of the CFRP were analyzed after tensile tests. Finally, the long-term performance of CFRP as a dual-functional material in ICCP-SS system was discussed. Results show that the externally bonding CFRP in ICCP-SS system can not only protect the steel in chloride-contaminated concrete effectively but also maintain 70% of the original tensile strength of CFRP at a charge density of 744 A·h/m2. The expected service period of CFRP as a dual-functional material bonded to the chloride-contaminated concrete was determined to be more than 42.5 years.
A Comparison Study on the Characteristics of Nanofibrils Isolated from Fibers and Parenchyma Cells in Bamboo
Authors: Zhang Xiaofeng , Huang Hanxiao , Qing Yan , Wang Hankun , Li Xingong
Published: January 2020

In this study, bamboo fibers and parenchyma cells were separated by a physical water-medium method. To compare the characteristics of nanofibrils from these two types of cells, lignocellulose nanofibrils (LCNFs) and cellulose nanofibrils (CNFs) were prepared by different processes. Atomic force microscopy analysis revealed that both fibers and parenchyma cells can be separated into individual fibrils after grinding three times. However, LCNFs had a diameter of 20–40 nm, which was larger than that of CNFs (10–20 nm). Additionally, the films prepared from LCNFs had lower tensile strength, but higher hydrophobicity compared with those from CNFs. X-ray diffraction analysis and tensile test of the films showed that the nanofibrils isolated from fibers and parenchyma cells had similar crystallinity and mechanical properties. This study shows a promising application of bamboo parenchyma cells, which are usually discarded as waste in the processing of bamboo products, in the preparation of nanofibers.
Hybrid Al2O3-CH3NH3PbI3 Perovskites towards Avoiding Toxic Solvents
Authors: Wyn Jones Eurig , James Holliman Peter , Bowen Leon , Connell Arthur , Kershaw Christopher , Elizabeth Meza-Rojas Diana
Published: January 2020

We report the synthesis of organometal halide perovskites by milling CH3NH3I and PbI2 directly with an Al2O3 scaffold to create hybrid Al2O3-CH3NH3PbI3 perovskites, without the use of organic capping ligands that otherwise limit the growth of the material in the three dimensions. Not only does this improve the ambient stability of perovskites in air (100 min versus 5 min for dimethylformamide (DMF)-processed material), the method also uses much fewer toxic solvents (terpineol versus dimethylformamide). This has been achieved by solid-state reaction of the perovskite precursors to produce larger perovskite nanoparticles. The resulting hybrid perovskite–alumina particles effectively improve the hydrophobicity of the perovskite phase whilst the increased thermal mass of the Al2O3 increases the thermal stability of the organic cation. Raman data show the incorporation of Al2O3 shifts the perovskite spectrum, suggesting the formation of a hybrid 3D mesoporous stack. Laser-induced current mapping (LBIC) and superoxide generation measurements, coupled to thermogravimetric analysis, show that these hybrid perovskites demonstrate slightly improved oxygen and thermal stability, whilst ultra-fast X-ray diffraction studies using synchrotron radiation show substantial (20×) increase in humidity stability. Overall, these data show considerably improved ambient stability of the hybrid perovskites compared to the solution-processed material.
Sustainable Closed-Loop Supply Chain Design Problem: A Hybrid Genetic Algorithm Approach
Authors: Yun YoungSu , Chuluunsukh Anudari , Gen Mitsuo
Published: January 2020

In this paper, we propose a solution to the sustainable closed-loop supply chain (SCLSC) design problem. Three factors (economic, environmental, and social) are considered for the problem and the three following requirements are addressed while satisfying associated constraint conditions: (i) minimizing the total cost; (ii) minimizing the total amount of CO2 emission during production and transportation of products; (iii) maximizing the social influence. Further, to ensure the efficient distribution of products through the SCLSC network, three types of distribution channels (normal delivery, direct delivery, and direct shipment) are considered, enabling a reformulation of the problem as a multi-objective optimization problem that can be solved using Pareto optimal solutions. A mathematical formulation is proposed for the problem, and it is solved using a hybrid genetic algorithm (pro-HGA) approach. The performance of the pro-HGA approach is compared with those of other conventional approaches at varying scales, and the performances of the SCLSC design problems with and without three types of distribution channels are also compared. Finally, we prove that the pro-HGA approach outperforms its competitors, and that the SCLSC design problem with three types of distribution channels is more efficient than that with a single distribution channel.
Exact Solutions to the Maxmin Problem max‖Ax‖ Subject to ‖Bx‖≤1
Authors: Moreno-Pulido Soledad , Garcia-Pacheco Francisco Javier , Cobos-Sanchez Clemente , Sanchez-Alzola Alberto
Published: January 2020

In this manuscript we provide an exact solution to the maxmin problem max ∥ A x ∥ subject to ∥ B x ∥ ≤ 1 , where A and B are real matrices. This problem comes from a remodeling of max ∥ A x ∥ subject to min ∥ B x ∥ , because the latter problem has no solution. Our mathematical method comes from the Abstract Operator Theory, whose strong machinery allows us to reduce the first problem to max ∥ C x ∥ subject to ∥ x ∥ ≤ 1 , which can be solved exactly by relying on supporting vectors. Finally, as appendices, we provide two applications of our solution: first, we construct a truly optimal minimum stored-energy Transcranian Magnetic Stimulation (TMS) coil, and second, we find an optimal geolocation involving statistical variables.
Commutativity of a 3-Prime near Ring Satisfying Certain Differential Identities on Jordan Ideals
Authors: Ali Asma , Huque Inzamam ul
Published: January 2020

The purpose of this study is to obtain the commutativity of a 3-prime near ring satisfying some differential identities on Jordan ideals involving derivations and multiplicative derivations. Further, herein we discuss some examples to show the necessity of the hypothesis to our results.
XVI International Symposium on Marine Natural Products|XI European Conference on Marine Natural Products
Authors: Pedrosa Rui , P. Gaudêncio Susana , Vasconcelos Vitor
Published: January 2020

The International Symposium on Marine Natural Products (MaNaPro) happened for the first time in 1975 in the city of Aberdeen, Scotland, organized by Professor Ronald H [...]
Ectoine from Bacterial and Algal Origin Is a Compatible Solute in Microalgae
Authors: Fenizia Simona , Thume Kathleen , Wirgenings Marino , Pohnert Georg
Published: January 2020

Osmoregulation in phytoplankton is attributed to several highly polar low-molecular-weight metabolites. A widely accepted model considers dimethylsulfoniopropionate (DMSP) as the most important and abundant osmotically active metabolite. Using an optimized procedure for the extraction and detection of highly polar metabolites, we expand the group of phytoplankton osmolytes by identifying ectoine in several microalgae. Ectoine is known as a bacterial compatible solute, but, to the best of our knowledge, was never considered as a phytoplankton-derived product. Given the ability of microalgae to take up zwitterions, such as DMSP, we tested the hypothesis that the algal ectoine is derived from associated bacteria. We therefore analyzed methanol extracts of xenic and axenic cultures of two different species of microalgae and could detect elevated concentrations of ectoine in those that harbor associated bacteria. However, also microalgae without an associated microbiome contain ectoine in smaller amounts, pointing towards a dual origin of this metabolite in the algae from their own biosynthesis as well as from uptake. We also tested the role of ectoine in the osmoadaptation of microalgae. In the model diatoms Thalassiosira weissflogii and Phaeodactylum tricornutum, elevated amounts of ectoine were found when cultivated in seawater with salinities of 50 PSU compared to the standard culture conditions of 35 PSU. Therefore, we add ectoine to the family of osmoadaptive metabolites in phytoplankton and prove a new, potentially synergistic metabolic interplay of bacteria and algae.
Gas Permeation Property of Silicon Carbide Membranes Synthesized by Counter-Diffusion Chemical Vapor Deposition
Authors: Nagano Takayuki , Sato Koji , Kawahara Koichi
Published: January 2020

An amorphous silicon carbide (SiC) membrane was synthesized by counter-diffusion chemical vapor deposition (CDCVD) using silacyclobutane (SCB) at 788 K. The SiC membrane on a Ni-γ-alumina (Al2O3) α-coated Al2O3 porous support possessed a H2 permeance of 1.2 × 10−7 mol·m−2·s−1·Pa−1 and an excellent H2/CO2 selectivity of 2600 at 673 K. The intermittent action of H2 reaction gas supply and vacuum inside porous support was very effective to supply source gas inside mesoporous intermediate layer. A SiC active layer was formed inside the Ni-γ-Al2O3 intermediate layer. The thermal expansion coefficient mismatch between the SiC active layer and Ni-γ-Al2O3-coated α-Al2O3 porous support was eased by the low decomposition temperature of the SiC source and the membrane structure.
The Influence of Texture on the Ductile-to-Brittle Transition Behavior in Fe20Cr4.5Al Oxide Dispersion Strengthened Alloy
Authors: Chao Jesus , Capdevila Carlos
Published: January 2020

This paper reports on hardness, tensile properties and notch impact bending toughness values of an Fe20Cr4.5Al oxide dispersion strengthened (ODS) alloy specifically processed to achieved different preferential orientations: random, <100>, <110> and <111> parallel to the bar axis. In spite of the differences in the grain size, it was found for <100>, <111> and random orientations that the mean hardness values on the transverse cross sections is not remarkably sensitive to the texture. On the other hand, a significantly different mean hardness value for the material having the <110> crystalline orientation was found. Regarding the yield strength, it was found for random, <100> and <111> orientations that the yield strength is proportional to the Taylor’s factor. The difference between experimental and predicted yield strength values for <110> orientation was attributed to the offset effect induced by the dislocation cell size. The variation of the cleavage fracture strength with the texture was analyzed in the basis of two criteria: one based on the Normal Stress Law (macroscopic nature), and the other based on the assumption that fracture occurs from the propagation of a microcrack-like defect (microscopic nature). In this sense, it was concluded from the fractographic evidences that random and <100> orientations follow a mechanism where the fracture kinks along of the cleavage plane from a penny shaped microcrack nucleated in a second phase particle, meanwhile in the <110> and <111> orientations the fracture propagation arises from a penny shaped defect on the cleavage plane. Finally, the lower shelf values determined for the conditions studied are the same regardless of the texture and microstructure. The effect of texture on the notch toughness was noted where plastic flow predominates, i.e., in the ductile to brittle transition temperature and in the upper shelf energy.
Impact of Precipitate Morphology on the Dissolution and Grain-Coarsening Behavior of a Ti-Nb Microalloyed Linepipe Steel
Authors: Solis-Bravo Gregorio , Merwin Matthew , Garcia C. Isaac
Published: January 2020

The relationship between precipitate morphology and dissolution on grain coarsening behavior was studied in two Ti-Nb microalloyed Linepipe (LP) Steels. The developed understanding highlights the importance of the complex relationship between precipitate constitutive make-up, dissolution mechanism and grain boundary (GB) pinning force. Equilibrium-based empirical solubility products were used to calculate precipitate volume fractions and compared to experimental measurements. Scanning Electron Microscopy (SEM), Electron Backscatter Diffraction (EBSD) and Electron Probe Micro-Analysis (EPMA) were conducted on bulk samples. Transmission Electron Microscopy (TEM)-based techniques were used on C-replica extractions and thin-foils. A retardation in the grain-coarsening temperature compared to the predicted coarsening temperature based on equilibrium calculations was noticed. In addition, a consistent NbC epitaxial formation over pre-existing TiN was observed. The resulting reduction in total precipitate/matrix interface area and the low energy of the TiN/NbC interface are pointed to as responsible mechanisms for the retardation in the kinetics of precipitates’ dissolution. This dissolution retardation mechanism suggests that a lower Nb content might be effective in controlling the grain coarsening behavior of austenite.
Through-Thickness Microstructure and Strain Distribution in Steel Sheets Rolled in a Large-Diameter Rolling Process
Authors: Inoue Tadanobu , Qiu Hai , Ueji Rintaro
Published: January 2020

The rolling condition for fabricating a low-carbon niobium-microalloyed steel sheet with an ultrafine-grained (UFG) structure was examined through rolling experiments and finite element analysis. A large-diameter rolling process was proposed to create a UFG structure. The rolling was conducted near the transformation point, Ar3, from austenite to ferrite. The Ar3 was measured at the surface and the center of the sheet. First, the through-thickness microstructure and equivalent strain distribution in a 1-pass rolled sheet 2.0 mm thick were examined. In the rolling experiments, the embedded pin method was employed to understand through-thickness deformation. The magnitude of the equivalent strain to obtain a UFG structure was estimated to be 2.0. Based on these results, the fabrication of a 2 mm UFG steel sheet by 3-pass rolling for an initial thickness of 14.5 mm was attempted by the proposed large-diameter rolling process.
Verification of Fuzzy Inference System for Cutting Speed while WEDM for the Abrasion-Resistant Steel Creusabro by Conventional Statistical Methods
Authors: Mouralova Katerina , Hrabec Pavel , Benes Libor , Otoupalik Jan , Bednar Josef , Prokes Tomas , Matousek Radomil
Published: January 2020

Wire electrical discharge machining is an unconventional machining method for the production of complex-shaped and very precise parts. Because of the high energy consumption of this machining process, it is necessary to maximize the cutting speed for its appropriate implementation. The abrasion-resistant steel Creusabro 4800 was chosen as the test material for this experiment, which is widely used especially for machines working in mines and quarries. In order to maximize the cutting speed, a fuzzy inference system (FIS) has been built, which uses 18 expert propositions to “model” the cutting speed based on five selected input parameters: gap voltage, pulse on time, pulse off time, discharge current, and wire feed. The obtained results were further verified by a design of experiment consisting of 33 tests for five selected input factors. Using the fuzzy inference system, the optimum machine parameters setup was found to maximize the cutting speed, in which the gap voltage = 60 V, pulse on time = 10 µs, pulse off time = 30 µs, wire feed = 10 m∙min−1 and discharge current = 35 A. The predicted value of the cutting speed using the fuzzy inference system is 6.471 mm∙min−1.
Finite Element Analysis of Laser Peening of Thin Aluminum Structures
Authors: Langer Kristina , Spradlin Thomas J. , Fitzpatrick Michael E.
Published: January 2020

Laser shock peening has become a commonly applied industrial surface treatment, particularly for high-strength steel and titanium components. Effective application to aluminum alloys, especially in the thin sections common in aerospace structures, has proved more challenging. Previous work has shown that some peening conditions can introduce at-surface tensile residual stress in thin Al sections. In this study, we employ finite element modeling to identify the conditions that cause this to occur, and show how these adverse effects can be mitigated through selection of peen parameters and patterning.
Production and Properties of Light Metal Matrix Nanocomposites
Authors: Dieringa Hajo
Published: January 2020

Metal matrix nanocomposites (MMNCs) with a light metal matrix are hybrid materials that have recently become the focus of interest for materials scientists and industry [...]
Metabolomics Provide Sensitive Insights into the Impacts of Low Level Environmental Contamination on Fish Health—A Pilot Study
Authors: Long Sara M. , Tull Dedreia L. , De Souza David P. , Kouremenos Konstantinos A. , Dayalan Saravanan , McConville Malcolm J. , Hassell Kathryn L. , Pettigrove Vincent J. , Gagnon Marthe Monique
Published: January 2020

This exploratory study aims to investigate the health of sand flathead (Platycephalus bassensis) sampled from five sites in Port Phillip Bay, Australia using gas chromatography-mass spectrometry (GC-MS) metabolomics approaches. Three of the sites were the recipients of industrial, agricultural, and urban run-off and were considered urban sites, while the remaining two sites were remote from contaminant inputs, and hence classed as rural sites. Morphological parameters as well as polar and free fatty acid metabolites were used to investigate inter-site differences in fish health. Significant differences in liver somatic index (LSI) and metabolite abundance were observed between the urban and rural sites. Differences included higher LSI, an increased abundance of amino acids and energy metabolites, and reduced abundance of free fatty acids at the urban sites compared to the rural sites. These differences might be related to the additional energy requirements needed to cope with low-level contaminant exposure through energy demanding processes such as detoxification and antioxidant responses as well as differences in diet between the sites. In this study, we demonstrate that metabolomics approaches can offer a greater level of sensitivity compared to traditional parameters such as physiological parameters or biochemical markers of fish health, most of which showed no or little inter-site differences in the present study. Moreover, the metabolite responses are more informative than traditional biomarkers in terms of biological significance as disturbances in specific metabolic pathways can be identified.
Mixing Optimization in Grooved Serpentine Microchannels
Authors: Rhoades Tyler , Kothapalli Chandrasekhar R. , Fodor Petru S.
Published: January 2020

Computational fluid dynamics modeling at Reynolds numbers ranging from 10 to 100 was used to characterize the performance of a new type of micromixer employing a serpentine channel with a grooved surface. The new topology exploits the overlap between the typical Dean flows present in curved channels due to the centrifugal forces experienced by the fluids, and the helical flows induced by slanted groove-ridge patterns with respect to the direction of the flow. The resulting flows are complex, with multiple vortices and saddle points, leading to enhanced mixing across the section of the channel. The optimization of the mixers with respect to the inner radius of curvature (Rin) of the serpentine channel identifies the designs in which the mixing index quality is both high (M > 0.95) and independent of the Reynolds number across all the values investigated.
The Geochronology and Geochemistry of Zircon as Evidence for the Reconcentration of REE in the Triassic Period in the Chungju Area, South Korea
Authors: No Sang-Gun , Park Maeng-Eon
Published: January 2020

The Chungju rare-earth element (REE) deposit is located in the central part of the Okcheon Metamorphic Belt (OMB) in the Southern Korean Peninsula and research on REE mineralization in the Gyemyeongsan Formation has been continuous since the first report in 1989. The genesis of the REE mineralization that occurred in the Gyemyeongsan Formation has been reported by previous researchers; theories include the fractional crystallization of alkali magma, magmatic hydrothermal alteration, and recurrent mineralization during metamorphism. In the Gyemyeongsan Formation, we discovered an allanite-rich vein that displays the paragenetic relationship of quartz, allanite, and zircon, and we investigated the chemistry and chronology of zircon obtained from this vein. We analyzed the zircon’s chemistry with an electron probe X-ray micro analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The grain size of the zircon is as large as 50 µm and has an inherited core (up to 15 µm) and micrometer-sized sector zoning (up to several micrometers in size). In a previous study, the zircon ages were not obtained because the grain size was too small to analyze. In this study, we analyzed the zircon with laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) for dating purposes. The REE patterns and occurrence of zircon in the quartz–allanite vein match well with previous reported recrystallized zircon, while the behavior of the trace elements shows differences with magmatic and hydrothermal zircon. The 206Pb/238U ages obtained from the zircon in the quartz–allanite vein are from 240.1 ± 2.9 to 257.1 ± 3.5 Ma and this age is included in the tectonic evolution period of the study area. Therefore, we suggest that the quartz–allanite veins in the Gyemyeongsan Formation were formed during the late Permian to early Triassic metamorphic period and the zircon was recrystallized at that time. The Triassic age is the first reported age with zircon dating in the Gyemyeongsan Formation and will be an important data-point for the study of the tectonic evolution of the OMB.
Extraction of High Value Triterpenic Acids from Eucalyptus globulus Biomass Using Hydrophobic Deep Eutectic Solvents
Authors: Silva Nuno H. C. S. , Morais Eduarda S. , Freire Carmen S. R. , Freire Mara G. , Silvestre Armando J. D.
Published: January 2020

Triterpenic acids (TTAs), known for their promising biological properties, can be found in different biomass sources and related by-products, such as Eucalyptus globulus bark, and have been extracted using organic volatile solvents such as dichloromethane. Recently, deep eutectic solvents (DES) have been identified as promising alternatives for the extraction of value-added compounds from biomass. In the present work, several hydrophobic DES were tested for the extraction of TTAs from E. globulus bark. Initial solubility studies revealed that DES based on menthol and thymol as the most promising solvents for these compounds given the highest solubilities obtained for ursolic acid (UA) at temperatures ranging from room temperature up to 90 °C. Accordingly, an eutectic mixture of menthol:thymol (1:2) was confirmed as the best candidate for the TTAs extraction from E. globulus outer bark, leading to extraction yields (weight of TTA per weight of biomass) at room temperature of 1.8 wt% for ursolic acid, 0.84 wt% for oleanolic acid and 0.30 wt% for betulinic acid. These values are significantly higher than those obtained with conventional organic solvents under similar conditions. The results obtained using these DES are promising for the recovery of TTAs for nutraceutical and pharmacological applications, while reinforcing the potential of DES as promising solvents to be applied in biorefinery processes.
Astaxanthin Protects PC12 Cells against Homocysteine- and Glutamate-Induced Neurotoxicity
Authors: Chang Chi-Huang , Chen Kuan-Chou , Liaw Kuo-Chun , Peng Chiung-Chi , Peng Robert Y.
Published: January 2020

Memory impairment has been shown to be associated with glutamate (Glu) excitotoxicity, homocysteine (Hcy) accumulation, and oxidative stress. We hypothesize that Glu and Hcy could damage neuronal cells, while astaxanthin (ATX) could be beneficial to alleviate the adverse effects. Using PC12 cell model, we showed that Glu and Hcy provoked a huge amount of reactive oxygen species (ROS) production, causing mitochondrial damage at EC50 20 and 10 mm, respectively. The mechanisms of action include: (1) increasing calcium influx; (2) producing ROS; (3) initiating lipid peroxidation; (4) causing imbalance of the Bcl-2/Bax homeostasis; and (5) activating cascade of caspases involving caspases 12 and 3. Conclusively, the damages caused by Glu and Hcy to PC12 cells can be alleviated by the potent antioxidant ATX.
Synthesis, Structural Characterization, and Biological Activity of New Pyrazolo[4,3-e][1,2,4]triazine Acyclonucleosides
Authors: Mojzych Mariusz , Bernat Zofia , Karczmarzyk Zbigniew , Matysiak Joanna , Fruziński Andrzej
Published: January 2020

A series of new pyrazolo[4,3-e][1,2,4]triazine acyclonucleosides 2–5 and 8 were prepared and evaluated for their anticancer activity against human cancer cell lines (MCF-7, K-562) and CDK2/E, as well as Abl protein kinases inhibitors. Lipophilicity of the compounds was determined using C-18 and immobilized artificial membrane (IAM) chromatography. In order to confirm the molecular structures and synthesis pathway of new acyclonucleosides, X-ray analysis was performed for model compound 3. Theoretical calculations at the DFT/B3LYP/6-311++G(d,p) level were used for the characterization of electronic structures of 1–8. The potential antiviral activity of acyclonucleosides 2–8 was tested in silico using molecular docking method.
Bioplatform Fabrication Approaches Affecting Chitosan-Based Interpolymer Complex Properties and Performance as Wound Dressings
Authors: Mndlovu Hillary , du Toit Lisa C. , Kumar Pradeep , Choonara Yahya E. , Marimuthu Thashree , Kondiah Pierre P. D. , Pillay Viness
Published: January 2020

Chitosan can form interpolymer complexes (IPCs) with anionic polymers to form biomedical platforms (BMPs) for wound dressing/healing applications. This has resulted in its application in various BMPs such as gauze, nano/microparticles, hydrogels, scaffolds, and films. Notably, wound healing has been highlighted as a noteworthy application due to the remarkable physical, chemical, and mechanical properties enabled though the interaction of these polyelectrolytes. The interaction of chitosan and anionic polymers can improve the properties and performance of BMPs. To this end, the approaches employed in fabricating wound dressings was evaluated for their effect on the property–performance factors contributing to BMP suitability in wound dressing. The use of chitosan in wound dressing applications has had much attention due to its compatible biological properties. Recent advancement includes the control of the degree of crosslinking and incorporation of bioactives in an attempt to enhance the physicochemical and physicomechanical properties of wound dressing BMPs. A critical issue with polyelectrolyte-based BMPs is that their effective translation to wound dressing platforms has yet to be realised due to the unmet challenges faced when mimicking the complex and dynamic wound environment. Novel BMPs stemming from the IPCs of chitosan are discussed in this review to offer new insight into the tailoring of physical, chemical, and mechanical properties via fabrication approaches to develop effective wound dressing candidates. These BMPs may pave the way to new therapeutic developments for improved patient outcomes.
Biocompatible Organic Coatings Based on Bisphosphonic Acid RGD-Derivatives for PEO-Modified Titanium Implants
Authors: Parfenova Lyudmila V. , Lukina Elena S. , Galimshina Zulfia R. , Gil’fanova Guzel U. , Mukaeva Veta R. , Farrakhov Ruzil G. , Danilko Ksenia V. , Dyakonov Grigory S. , Parfenov Evgeny V.
Published: January 2020

Currently, significant attention is attracted to the problem of the development of the specific architecture and composition of the surface layer in order to control the biocompatibility of implants made of titanium and its alloys. The titanium surface properties can be tuned both by creating an inorganic sublayer with the desired morphology and by organic top coating contributing to bioactivity. In this work, we developed a composite biologically active coatings based on hybrid molecules obtained by chemical cross-linking of amino acid bisphosphonates with a linear tripeptide RGD, in combination with inorganic porous sublayer created on titanium by plasma electrolytic oxidation (PEO). After the addition of organic molecules, the PEO coated surface gets nobler, but corrosion currents increase. In vitro studies on proliferation and viability of fibroblasts, mesenchymal stem cells and osteoblast-like cells showed the significant dependence of the molecule bioactivity on the structure of bisphosphonate anchor and the linker. Several RGD-modified bisphosphonates of β-alanine, γ-aminobutyric and ε-aminocaproic acids with BMPS or SMCC linkers can be recommended as promising candidates for further in vivo research.
Potential of Thai Herbal Extracts on Lung Cancer Treatment by Inducing Apoptosis and Synergizing Chemotherapy
Authors: Poofery Juthathip , Khaw-on Patompong , Subhawa Subhawat , Sripanidkulchai Bungorn , Tantraworasin Apichat , Saeteng Somcharoen , Siwachat Sopon , Lertprasertsuke Nirush , Banjerdpongchai Ratana
Published: January 2020

The incidence of lung cancer has increased while the mortality rate has continued to remain high. Effective treatment of this disease is the key to survival. Therefore, this study is a necessity in continuing research into new effective treatments. In this study we determined the effects of three different Thai herbs on lung cancer. Bridelia ovata, Croton oblongifolius, and Erythrophleum succirubrum were extracted by ethyl acetate and 50% ethanol. The cytotoxicity was tested with A549 lung cancer cell line. We found four effective extracts that exhibited toxic effects on A549 cells. These extracts included ethyl acetate extracts of B. ovata (BEA), C. oblongifolius (CEA), and E. succirubrum (EEA), and an ethanolic extract of E. succirubrum (EE). Moreover, these effective extracts were tested in combination with chemotherapeutic drugs. An effective synergism of these treatments was found specifically through a combination of BEA with methotrexate, EE with methotrexate, and EE with etoposide. Apoptotic cell death was induced in A549 cells by these effective extracts via the mitochondria-mediated pathway. Additionally, we established primary lung cancer and normal epithelial cells from lung tissue of lung cancer patients. The cytotoxicity results showed that EE had significant potential to be used for lung cancer treatment. In conclusion, the four effective extracts possessed anticancer effects on lung cancer. The most effective extract was found to be E. succirubrum (EE).
Can We Safely Obtain Formal Oxidation States from Centroids of Localized Orbitals?
Authors: Gimferrer Martí , Comas-Vilà Gerard , Salvador Pedro
Published: January 2020

The use of centroids of localized orbitals as a method to derive oxidation states (OS) from first-principles is critically analyzed. We explore the performance of the closest-atom distance criterion to assign electrons for a number of challenging systems, including high-valent transition metal compounds, π-adducts, and transition metal (TM) carbenes. Here, we also introduce a mixed approach that combines the position of the centroids with Bader’s atomic basins as an alternative criterion for electron assignment. The closest-atom criterion performs reasonably well for the challenging systems, but wrongly considers O-H and N-H bonds as hydrides. The new criterion fixes this problem, but underperforms in the case of TM carbenes. Moreover, the OS assignment in dubious cases exhibit undesirable dependence on the particular choice for orbital localization.
Preparation of Nano Silver Paste and Applications in Transparent Electrodes via Electric-Field Driven Micro-Scale 3D Printing
Authors: Li Hongke , Zhu Xiaoyang , Li Zhenghao , Yang Jianjun , Lan Hongbo
Published: January 2020

Nano-silver paste, as an important basic material for manufacturing thick film components, ultra-fine circuits, and transparent conductive films, has been widely used in various fields of electronics. Here, aiming at the shortcomings of the existing nano-silver paste in printing technology and the problem that the existing printing technology cannot achieve the printing of high viscosity, high solid content nano-silver paste, a nano-silver paste suitable for electric-field-driven (EFD) micro-scale 3D printing is developed. The result shows that there is no oxidation and settlement agglomeration of nano-silver paste with a storage time of over six months, which indicates that it has good dispersibility. We focus on the printing process parameters, sintering process, and electrical conductivity of nano-silver paste. The properties of the nano-silver paste were analyzed and the feasibility and practicability of the prepared nano-silver paste in EFD micro-scale 3D printing technology were verified. The experiment results indicate that the printed silver mesh which can act as transparent electrodes shows high conductivity (1.48 Ω/sq) and excellent transmittance (82.88%). The practical viability of the prepared nano-silver paste is successfully demonstrated with a deicing test. Additionally, the experimental results show that the prepared silver mesh has excellent heating properties, which can be used as transparent heaters.
ToxTracker Reporter Cell Lines as a Tool for Mechanism-Based (Geno)Toxicity Screening of Nanoparticles—Metals, Oxides and Quantum Dots
Authors: McCarrick Sarah , Cappellini Francesca , Kessler Amanda , Moelijker Nynke , Derr Remco , Hedberg Jonas , Wold Susanna , Blomberg Eva , Odnevall Wallinder Inger , Hendriks Giel , Karlsson Hanna L.
Published: January 2020

The increased use of nanoparticles (NPs) requires efficient testing of their potential toxic effects. A promising approach is to use reporter cell lines to quickly assess the activation of cellular stress response pathways. This study aimed to use the ToxTracker reporter cell lines to investigate (geno)toxicity of various metal- or metal oxide NPs and draw general conclusions on NP-induced effects, in combination with our previous findings. The NPs tested in this study (n = 18) also included quantum dots (QDs) in different sizes. The results showed a large variation in cytotoxicity of the NPs tested. Furthermore, whereas many induced oxidative stress only few activated reporters related to DNA damage. NPs of manganese (Mn and Mn3O4) induced the most remarkable ToxTracker response with activation of reporters for oxidative stress, DNA damage, protein unfolding and p53-related stress. The QDs (CdTe) were highly toxic showing clearly size-dependent effects and calculations suggest surface area as the most relevant dose metric. Of all NPs investigated in this and previous studies the following induce the DNA damage reporter; CuO, Co, CoO, CdTe QDs, Mn, Mn3O4, V2O5, and welding NPs. We suggest that these NPs are of particular concern when considering genotoxicity induced by metal- and metal oxide NPs.
Magnetic Immobilization of Pichia pastoris Cells for the Production of Recombinant Human Serum Albumin
Authors: Taghizadeh Seyedeh-Masoumeh , Ebrahiminezhad Alireza , Ghoshoon Mohammad Bagher , Dehshahri Ali , Berenjian Aydin , Ghasemi Younes
Published: January 2020

Magnetic immobilization as a novel technique was used to immobilize recombinant Pichia pastoris (GS115 Albumin) cells to produce human serum albumin (HSA). In this regard, magnetic nanoparticles (MNPs) coated with amino propyl triethoxy silane (APTES) were synthesized. P. pastoris cells were decorated with MNPs via nonspecific interactions. Decorated cells were magneto-responsible and easily harvested by applying an external magnetic field. The efficiency of magnetic immobilization (Ei) for cell removal was in direct relation with the MNP concentration and time of exposure to the magnetic field. By increasing the nanoparticles concentration, cells were harvested in a shorter period. Complete cell removal (Ei ≈ 100) was achieved in ≥0.5 mg/mL of MNPs in just 30 s. HSA is produced in an extremely high cell density (OD ~20) and it is the first time that magnetic immobilization was successfully employed for harvesting such a thick cell suspension. After 5 days of induction the cells, which were immobilized with 0.25 to 1 mg/mL of nanoparticles, showed an increased potency for recombinant HSA production. The largest increase in HSA production (38.1%) was achieved in the cells that were immobilized with 0.5 mg/mL of nanoparticles. These results can be considered as a novel approach for further developments in the P. pastoris-based system.
Nutritional Status, Dietary Intake, and Adherence to the Mediterranean Diet of Children with Celiac Disease on a Gluten-Free Diet: A Case-Control Prospective Study
Authors: Lionetti Elena , Antonucci Niki , Marinelli Michele , Bartolomei Beatrice , Franceschini Elisa , Gatti Simona , Catassi Giulia Naspi , Verma Anil K. , Monachesi Chiara , Catassi Carlo
Published: January 2020

The only effective treatment for celiac disease (CD) is a life-long strict gluten-free diet (GFD). Nutritional adequacy of the GFD has remained controversial and a matter of debate for a long time. No large case-control studies on children regarding the nutritional adequacy of the GFD has been performed. In this study, children diagnosed with CD on a GFD for ≥ 2 years were recruited. Controls were age and gender-matched healthy children not affected with CD. In both groups, anthropometric measurements and energy expenditure information were collected. Dietary assessment was performed by a 3-day food diary. Adherence to the Mediterranean diet was estimated by the KIDMED index. Overall, 120 children with CD and 100 healthy children were enrolled. No differences were found between CD children and controls in anthropometric measurements and energy expenditure. In the CD group, the daily intake of fats was significantly higher while the consumption of fiber was lower in comparison with the control group. The median KIDMED index was 6.5 in CD children and 6.8 in healthy controls. The diet of children with CD in this study was nutritionally less balanced than controls, with a higher intake of fat and a lower intake of fiber, highlighting the need for dietary counseling.
Increased Cellular Uptake of Polyunsaturated Fatty Acids and Phytosterols from Natural Micellar Oil
Authors: Röhrl Clemens , Stübl Flora , Maier Martin , Schwarzinger Bettina , Schwarzinger Clemens , Pitsch Johannes , Lanzerstorfer Peter , Iken Marcus , Weghuber Julian
Published: January 2020

The transport of hydrophobic compounds to recipient cells is a critical step in nutrient supplementation. Here, we tested the effect of phospholipid-based emulsification on the uptake of hydrophobic compounds into various tissue culture cell lines. In particular, the uptake of ω-3 fatty acids from micellar or nonmicellar algae oil into cell models for enterocytes, epithelial cells, and adipocytes was tested. Micellization of algae oil did not result in adverse effects on cell viability in the target cells. In general, both micellar and nonmicellar oil increased intracellular docosahexaenoic acid (DHA) levels. However, micellar oil was more effective in terms of augmenting the intracellular levels of total polyunsaturated fatty acids (PUFAs) than nonmicellar oil. These effects were rather conserved throughout the cells tested, indicating that fatty acids from micellar oils are enriched by mechanisms independent of lipases or lipid transporters. Importantly, the positive effect of emulsification was not restricted to the uptake of fatty acids. Instead, the uptake of phytosterols from phytogenic oils into target cells also increased after micellization. Taken together, phospholipid-based emulsification is a straightforward, effective, and safe approach to delivering hydrophobic nutrients, such as fatty acids or phytosterols, to a variety of cell types in vitro. It is proposed that this method of emulsification is suitable for the effective supplementation of numerous hydrophobic nutrients.
Taste, Nutrition, and Health
Authors: Tepper Beverly J , Barbarossa Iole Tomassini
Published: January 2020

The sensation of flavour reflects the complex integration of aroma, taste, texture, and chemesthetic (oral and nasal irritation cues) from a food or food component. Flavour is a major determinant of food palatability—the extent to which a food is accepted or rejected—and can profoundly influence diet selection, nutrition, and health. Despite recent progress, there are still gaps in knowledge on how taste and flavour cues are detected at the periphery, conveyed by the brainstem to higher cortical levels and then interpreted as a conscious sensation. Taste signals are also projected to central feeding centers where they can regulate hunger and fullness. Individual differences in sensory perceptions are also well known and can arise from genetic variation, environmental causes, or a variety of metabolic diseases, such as obesity, metabolic syndrome, and cancer. Genetic taste/smell variation could predispose individuals to these same diseases. Recent findings have also opened new avenues of inquiry, suggesting that fatty acids and carbohydrates may provide nutrient-specific signals informing the gut and brain of the nature of the ingested nutrients. This special issue on “Taste, Nutrition, and Health” presents original research communications and comprehensive reviews on topics of broad interest to researchers and educators in sensory science, nutrition, physiology, public health, and health care.