bluuebunny/crossref_metadata_2025 huggingface dataset:
Spillovers and Asset Allocation
Authors: Hoang Lai T. , Baur Dirk G.
Published: July 2021

There is a large and growing literature on spillovers but no study that systematically evaluates the importance of spillovers for portfolio management. This paper provides such an analysis and demonstrates that spillovers are fully embedded in estimates of expected returns, variances, and correlations and that estimation of spillovers is not necessary for asset allocation. Simulations of typical empirical spillover settings further show that same-frequency spillovers are often negligible and spurious.
SenseTrust: A Sentiment Based Trust Model in Social Network
Authors: Mohammadi Alireza , Hashemi Golpayegani Seyyed Alireza
Published: July 2021

Online social networks, as popular media and communications tools with their own extensive uses, play key roles in public opinion polls, politics, economy, and even governance. An important issue regarding these networks is the use of multiple sources of publishing or re-publishing news and propositions that can influence audiences depending on the level of trust in these sources between users. Therefore, estimating the level of trust in social networks between users can predict the extent of social networks’ impact on news and different publication and re-publication sources, and correspondingly provide effective strategies in news dissemination, advertisements, and other diverse contents for trustees. Therefore, trust is introduced and interpreted in the present study. A large portion of interactions in social networks is based on sending and receiving texts employing natural language processing techniques. A Hidden Markov Model (HMM) was designed via an efficient model, namely SenseTrust, to estimate the level of trust between users in social networks.
Ecological Corridor Construction Based on Least-Cost Modeling Using Visible Infrared Imaging Radiometer Suite (VIIRS) Nighttime Light Data and Normalized Difference Vegetation Index
Authors: Hu Jiameng , Liu Yanfang , Fang Jian
Published: July 2021

Anthropic pressure is one of the main drivers of landscape change and biodiversity loss. Artificial nighttime light, which can affect species behavior, is an important human-induced threat to biodiversity, but it is often ignored in ecological connectivity research. To mitigate the adverse impacts of artificial lighting on biodiversity, this study integrates artificial nighttime light in landscape ecology and analyzes the influence of artificial nighttime light on landscape connectivity. A quantitative approach integrating nighttime light brightness from a Visible Infrared Imaging Radiometer Suite (VIIRS) with a normalized difference vegetation index (NDVI) from a Moderate-resolution Imaging Spectroradiometer (MODIS) is proposed to estimate the matrix resistance, which can identify the sensitive areas that are disrupted by nighttime light. It was found that the nightscape in the study area is significantly disrupted by nighttime light and the matrix resistance in the center of the study area significantly increases. Compared to the least-cost routes from the NDVI, the “dark” least-cost ecological corridors constructed using our approach apparently change in both location and distance. The corridors moved to the outer suburbs and rural areas, and the maximum increase in distance of the least-cost paths was 37.94%. Due to less disturbance from human activity and the maintenance of a pristine nightscape, “dark” ecological corridors can reduce the adverse effects of night lights and contribute to biodiversity. However, natural habitats have been greatly affected by nighttime light with the increase in global illumination, and it is essential that we improve public awareness of light pollution and formulate light-reduction policies and legislation.
De-/Fencing Grasslands: Ongoing Boundary Making and Unmaking in Postcolonial Kenya
Authors: Løvschal Mette , Gravesen Marie Ladekjær
Published: July 2021

Across contemporary East Africa, fencing is spreading with incredible speed over hundreds of thousands of hectares of rangelands, fundamentally reconfiguring land tenure dynamics. But why is this happening now, what are the precursors, and what will happen in the years to come? In this article, we ask how pre- and post-colonial landscape gridding perpetuate a slow violence across the landscape through processes of de-/fencing. Fencing, we argue, is embedded in a landscape logic that favours exclusive rights and conditioned access. In two case studies from grazing lands in Kenya, we explore how people engage with the tension of an imposed landscape logic of fencing by either asserting or challenging its very physicality. We propose that de-/fencing are ways of anticipating long-standing land tenure uncertainties. Moreover, we use our cases to explore different points of reference along the mattering of land tenure boundaries as well as the sort of horizons to which fencing leads. We also use this knowledge to improve our understanding of parallel prehistoric cases of large-scale landscape enclosure. By unfolding the intertwined socio-political and material nature of gridded landscapes, we seek to bring the study of fencing out of conservation literature and into its wider culture-historical context.
High-Sensitivity C-Reactive Protein Relationship with Metabolic Disorders and Cardiovascular Diseases Risk Factors
Authors: Koziarska-Rościszewska Małgorzata , Gluba-Brzózka Anna , Franczyk Beata , Rysz Jacek
Published: July 2021

Background. Chronic inflammation is considered to be involved in the development of CVD. It is important to find a simple test that enables the identification of patients at risk and that may be used in primary care. The aim of this study is to investigate the associations of high-sensitivity C-reactive protein (hsCRP) with selected factors—age, gender, obesity, dyslipidemia, diabetes, hyperuricemia, vitamin D-25(OH)D, cardiovascular diseases (CVD), coronary heart disease, cerebrovascular disease, and hypertension. Results. Statistically significant correlations were found between hsCRP and the following: age (rs = 0.304, p = 0.0000); gender (female) (p = 0.0173); BMI (rs = 0.295, p = 0.0001); waist circumference (rs = 0.250, p = 0.0007); dyslipidemia (p = 0.0159); glycemia (rs = 0.173, p = 0.0207); and significant negative correlations between hsCRP and 25(OH)D (rs = −0.203, p = 0.0065). In patients with CVD, hypertension, diabetes, or visceral obesity, hsCRP was significantly higher than in the subgroup without these disorders. There was a statistically significant relationship between hsCRP and the number of the metabolic syndrome elements (p = 0.0053). Conclusions. The hsCRP test seem to be a simple test that may be used at the primary care level to identify patients at risk of metabolic disorders, CVD, and hypertension. Vitamin D concentration may be a determining factor of systemic inflammation (it may have a modulating effect).
Differences among Three Skeletal Muscle Mass Indices in Predicting Non-Alcoholic Fatty Liver Disease: Korean Nationwide Population-Based Study
Authors: Cho A-Ra , Lee Jun-Hyuk , Kwon Yu-Jin
Published: July 2021

Recent studies have investigated the relationship between sarcopenia and non-alcoholic fatty liver disease (NAFLD); however, there is no unified definition of sarcopenia. Thus, we aimed to investigate the differences among three skeletal muscle mass indices (SMI) in predicting NAFLD. This study included 8133 adults from the 2008–2010 Korea National Health and Nutrition Survey. SMI was calculated as appendicular skeletal muscle mass divided by height-square (hSMI), weight (wSMI), or body mass index (bSMI). The presence of NAFLD was defined by using the NAFLD-liver fat score. On the receiver operating characteristic curve analysis, the predictive power of wSMI for NAFLD was significantly higher than those of hSMI and bSMI in men (wSMI vs. hSMI, p = 0.003; wSMI vs. bSMI, p < 0.001). In women, the predictive power of hSMI was only significantly higher than that of bSMI (p = 0.023), and other predictive powers were not significantly different. In addition, hSMI was correlated with insulin resistance and NAFLD-liver fat score in the opposite direction to wSMI and bSMI in both men and women. Among the three definitions of SMI, wSMI showed the highest diagnostic performance for predicting NAFLD in men, suggesting the importance of defining sarcopenia for its association with specific diseases.
Efficacy of Different Types of Therapy for COVID-19: A Comprehensive Review
Authors: Starshinova Anna , Malkova Anna , Zinchenko Ulia , Kudlay Dmitry , Glushkova Anzhela , Dovgalyk Irina , Yablonskiy Piotr , Shoenfeld Yehuda
Published: July 2021

A new coronavirus disease (COVID-19) has already affected millions of people in 213 countries. The possibilities of treatment have been reviewed in recent publications but there are many controversial results and conclusions. An analysis of the studies did not reveal a difference in mortality level between people treated with standard therapy, such as antiviral drugs and dexamethasone, and new antiviral drugs/additional immune therapy. However, most studies describe clinical improvement and a decrease in mortality among patients with severe and critical conditions, with the early initiation of additional immune therapy. Possible new targets based on viral life cycles were considered. Unfortunately, the data analysis on the efficacy of different medicine and therapy regimens among patients with COVID-19, showed little success in decreasing the mortality rate in all treatment methods. Some efficacy has been shown with an immunosuppressive therapy in small patient samples, but when a larger number of patients were analyzed the data did not differ significantly from the control groups.
Stipa tenacissima L.: A New Promising Source of Bioactive Compounds with Antioxidant and Anticancer Potentials
Authors: El Bouchti Mehdi , Bourhia Mohammed , Alotaibi Amal , Aghmih Kaoutar , Majid Sanaa , Ullah Riaz , Salamatullah Ahmad Mohammad , El Achaby Mounir , Oumam Mina , Hannache Hassan , Cherkaoui Omar , El Mzibri Mohammed , Benbacer Laila , Gmouh Said
Published: July 2021

Background: Stipa tenacissima L. (S. tenacissima), called Esparto grass, is a cultivated species used for industrial purposes, including textile production. This species has never been studied for its medical potential before, nor has it been used in traditional medicines. It is thus fitting that the present study aimed to investigate the pharmacological potential of S. tenacissima. To achieve this goal, this work was conducted to study the chemical composition, antioxidant properties, and antiproliferative effects of S. tenacissima against cancerous cell lines, including the human colorectal adenocarcinoma cell line (HT-29) and human breast adenocarcinoma cell line (MDA-MB-231). Fractionation and characterization of S. tenacissima extract showed the presence of promising bioactive fractions. The fractions obtained from S. tenacissima extract exhibited interesting antioxidant properties, with IC50 values ranging from 1.26 to 1.85 mg/mL. All fractions, such as F1, F2, F3, and F4, induced an important antiproliferative effect on the cancer cell lines MDA-MB-231, scoring IC50 values ranging from 63.58 ± 3.14 to 99.880 ± 0.061 µg/mL. These fractions (F1, F2, F3, and F4) also exhibited a potent antiproliferative effect versus HT-29 cell lines, with IC50 values ranging from 71.50 ± 4.97 to 87.500 ± 1.799 µg/mL. Therefore, S. tenacissima could constitute a new natural source of bioactive compounds that can be used for therapeutic purposes to fight cancer and free radical damage.
Low Friction Powertrains: Current Advances in Lubricants and Coatings
Authors: Lee Peter , Zhmud Boris
Published: July 2021

Improving fuel economy and reducing emissions is nowadays more important than ever. Apart from powertrain electrification, automotive manufacturers have constantly been seeking to improve the efficiency of the internal combustion engine. Downsizing and boosting have become common practice in the internal combustion engine (ICE) design. Increased power density and torque output of modern boosted engines, in combination with the introduction of automatic stop-start systems and ultralow viscosity lubricants tends to stress the engine beyond the limits foreseen in the classical design. This leads to wear problems. Each engine component comes with a unique landscape of competing manufacturing technologies, among which advanced surface finishing and coating methods play an important role. This presentation provides an overview of different industrial trends related thereto. The role of lubricant on the engine tribology is studied for different engine designs. The importance of in-design “pairing” of low-viscosity motor oils with the engine characteristics is highlighted filling the gap in the understanding of complex interactions between the crankcase lubricant and engine mechanics.
Poly[3-methyl-1,3-oxazolidin-2-iminium[µ3-cyanido-tri-µ2-cyanido-κ9C:N-tricuprate(I)]]
Authors: Rachid Leena N. , Corfield Peter W. R.
Published: July 2021

The unexpected formation of an oxazole ring has occurred during synthesis of a copper(I) cyanide network polymer as part of our ongoing studies of the structural chemistry of these networks. Crystals of the title compound were formed during the synthesis of a previously reported CuCN network solid containing protonated N-methylethanolamine and have been characterized by single crystal X-ray structure analysis. The structure shows well-defined oxazole-2-iminium cations sitting in continuous channels along the short a-axis of the crystal in a new three-dimensional copper(I) cyanide polymeric network. Evidently, a reaction has occurred between the cyanide ion and the protonated N-methylethanolamine base.
Valorization of Aluminum Dross with Copper via High Temperature Melting to Produce Al-Cu Alloys
Authors: Kudyba Artur , Akhtar Shahid , Johansen Inge , Safarian Jafar
Published: July 2021

The valorization of aluminum dross for Al recovery was performed via its mixing with metallic copper to produce Al-Cu alloys. This approach was with the intention of establishing a new smelting process to treat the dross with Cu scrap use. To evaluate the high temperature interaction of the materials, the wettability of a Cu-containing aluminum alloy with the non-metallic components of the dross was studied by the sessile drop method. It was found that the wetting was weak via temperature changes at 973–1373 K, and consequently no proper metal separation occurred. To better separate the metallic and non-metallic phases with larger density differences, a higher Cu portion was considered to obtain a significantly denser metallic phase, and it was found that partial separation of the Al in an Al-Cu alloy is possible. The complete separation of the metallic components of the dross was, however, experienced by the dross and copper melting with the addition of pre-melted calcium aluminate slags at elevated temperatures. It was found that Al-Cu alloys were produced and separated from the adjacent slags, and the aluminum oxide of the dross ended up in the slag phase. Moreover, the characteristics of the produced slags depend on the process charge.
Computer Analysis of the Porous Structure of Activated Carbons Derived from Various Biomass Materials by Chemical Activation
Authors: Kwiatkowski Mirosław , Broniek Elżbieta
Published: July 2021

In this study, the preparation of activated carbons from various materials of biomass origin by activation with potassium hydroxide and a comprehensive computer analysis of their porous structure and adsorption properties based on benzene (C6H6) adsorption isotherms were carried out. In particular, the influence of the mass ratio of the activator’s dry mass to the char mass on the formation of the microporous structure of the obtained activated carbons was analysed. The summary of the analyses carried out based on benzene adsorption isotherms begged the conclusion that activated carbon with a maximum adsorption volume in the first adsorbed layer and homogeneous surface can be obtained from ebony wood at a mass ratio of the activator to the char of R = 3. The obtained results confirmed the superiority of the new numerical-clustering-based adsorption analysis (LBET) method over simple methods of porous structure analysis, such as the Brunauer–Emmett–Teller (BET) and Dubinin–Raduskevich (DR) methods. The LBET method is particularly useful in the evaluation of the influence of the methods and conditions of production of activated carbons on the formation of their porous structure. This method, together with an appropriate economic analysis, can help in the precise selection of methods and conditions for the process of obtaining activated carbons at specific manufacturing costs, and thus makes it possible to obtain materials that can successfully compete with those of other technologies used in industrial practice and everyday life.
AFM and Fluorescence Microscopy of Single Cells with Simultaneous Mechanical Stimulation via Electrically Stretchable Substrates
Authors: Becerra Natalia , Salis Barbara , Tedesco Mariateresa , Moreno Flores Susana , Vena Pasquale , Raiteri Roberto
Published: July 2021

We have developed a novel experimental set-up that simultaneously, (i) applies static and dynamic deformations to adherent cells in culture, (ii) allows the visualization of cells under fluorescence microscopy, and (iii) allows atomic force microscopy nanoindentation measurements of the mechanical properties of the cells. The cell stretcher device relies on a dielectric elastomer film that can be electro-actuated and acts as the cell culture substrate. The shape and position of the electrodes actuating the film can be controlled by design in order to obtain specific deformations across the cell culture chamber. By using optical markers we characterized the strain fields under different electrode configurations and applied potentials. The combined setup, which includes the cell stretcher device, an atomic force microscope, and an inverted optical microscope, can assess in situ and with sub-micron spatial resolution single cell topography and elasticity, as well as ion fluxes, during the application of static deformations. Proof of performance on fibroblasts shows a reproducible increase in the average cell elastic modulus as a response to applied uniaxial stretch of just 4%. Additionally, high resolution topography and elasticity maps on a single fibroblast can be acquired while the cell is deformed, providing evidence of long-term instrumental stability. This study provides a proof-of-concept of a novel platform that allows in situ and real time investigation of single cell mechano-transduction phenomena with sub-cellular spatial resolution.
Estimation of Phase Ratio in Bulk, Textured TWIP/TRIP Steels from Pole Figures
Authors: Benke Marton , Hlavacs Adrienn , Kristaly Ferenc , Sepsi Mate , Mertinger Valeria
Published: July 2021

The volume fraction of austenite (γ), ε martensite and α′ martensite is of key importance in the research of TWIP/TRIP steels. When mechanical loading is involved, the crystallographic texture also develops, which complicates X-ray diffraction-based phase ratio determination. The problem is more pronounced when only a couple, or only one Bragg-reflection can be measured. A solution for such cases is to determine the ratio of the phases based on the pole distribution function of a selected Bragg-reflection of the present phases. In this manuscript, this method is reconsidered for and applied to non-transmittable bulk specimens for the first time in the reflection mode of XRD pole figure measurements. First, the method was applied to a series of γ–α′ powder mixtures. The results were compared to those obtained by the Rietveld method. Afterwards, the technique was applied to strongly textured, bulk TWIP/TRIP steel specimens which were tensile tested at different temperatures. It was shown that the results of the presented method were close to those of the Rietveld technique in the case of powder mixtures. The results of the tensile-tested steels revealed that the α′ content increases with decreasing test temperatures, and the variation of the α′ ratio correlates very well with the ultimate tensile strength versus the temperature, confirming the contribution of the α′ content to the strength of TWIP/TRIP steels.
The Influence of Mixing Conditions on the Macro-Scale Homogeneity of Asphalt Mixtures Blended with Reclaimed Asphalt Pavement (RAP)
Authors: Liu Quan , Oeser Markus
Published: July 2021

The homogeneity of asphalt mixtures blended with reclaimed asphalt pavement (RAP) is affected by many factors. Due to the complicated compositions of recycled asphalt mixtures, the inhomogeneity issue might cause insufficient mechanical properties of asphalt mixtures, even though a design method was appropriately adopted. Therefore, it is of great significance to study the influence of mixing conditions on the homogeneity of asphalt mixtures blended with RAP materials. This study focused on the macro-scale homogeneity of produced asphalt mixtures. Specifically, asphalt mixtures incorporated with 40% RAP content were produced in a laboratory using different mixing times and mixing temperatures. A multi-direction indirect tensile stiffness modulus (ITSM) test was proposed to quantify the homogeneity of produced samples. In addition, the digital image processing (DIP) method was used to identify the distribution of aggregates and RAP binder. The results indicated that the influence of mixing time on the macro-homogeneity of asphalt mixtures indicated that a longer mixing time was favorable for the material dispersion. The influence of mixing temperature mainly rested on two perspectives. One was that the temperature variation induced the change of binder viscosity. The other was that the temperature influences the diffusion process between RAP binder and new bitumen, which further affected the mechanical performance of produced asphalt mixtures.
Computer Simulation of Hydrodynamic and Thermal Processes in DLD Technology
Authors: Turichin Gleb A. , Valdaytseva Ekaterina A. , Stankevich Stanislav L. , Udin Ilya N.
Published: July 2021

This article deals with the theoretical issues of the formation of a melt pool during the process of direct laser deposition. The shape and size of the pool depends on many parameters, such as the speed and power of the process, the optical and physical properties of the material, and the powder consumption. On the other hand, the influence of the physical processes occurring in the material on one another is significant: for instance, the heating of the powder and the substrate by laser radiation, or the formation of the free surface of the melt, taking into account the Marangoni effect. This paper proposes a model for determining the size of the melt bath, developed in a one-dimensional approximation of the boundary layer flow. The dimensions and profile of the surface and bottom of the melt pool are obtained by solving the problem of convective heat transfer. The influence of the residual temperature from the previous track, as well as the heat from the heated powder of the gas–powder jet, taking into account its spatial distribution, is considered. The simulation of the size and shape of the melt pool, as well as its free surface profile for different alloys, is performed with 316 L steel, Inconel 718 nickel alloy, and VT6 titanium alloy
Polyelectrolyte Multilayers: An Overview on Fabrication, Properties, and Biomedical and Environmental Applications
Authors: Petrila Larisa-Maria , Bucatariu Florin , Mihai Marcela , Teodosiu Carmen
Published: July 2021

Polyelectrolyte multilayers are versatile materials that are used in a large number of domains, including biomedical and environmental applications. The fabrication of polyelectrolyte multilayers using the layer-by-layer technique is one of the simplest methods to obtain composite functional materials. The properties of the final material can be easily tuned by changing the deposition conditions and the used building blocks. This review presents the main characteristics of polyelectrolyte multilayers, the fabrication methods currently used, and the factors influencing the layer-by-layer assembly of polyelectrolytes. The last section of this paper presents some of the most important applications of polyelectrolyte multilayers, with a special focus on biomedical and environmental applications.
Effect of Exchangeable Ions in Natural and Modified Zeolites on Ag Content, Ag Nanoparticle Formation and Their Antibacterial Activity
Authors: Mintcheva Neli , Panayotova Marinela , Gicheva Gospodinka , Gemishev Orlin , Tyuliev Georgy
Published: July 2021

To broaden the application of silver nanoparticles (AgNPs), which are well-known antibacterial agents, they are supported on different substrates to prevent aggregation, increase their surface area and antibacterial efficiency, and to be separated from the system more effectively at the end of treatment. To produce nanocomposites that consist of silver nanoparticles on natural and modified zeolites, silver ions (Ag+) were loaded onto zeolite (natural, Na-modified, H-modified) and then thermally reduced to AgNPs. The effect of the exchangeable cations in zeolite on Ag+ uptake, AgNPs formation, size and morphology was investigated by the TEM, SEM, EDX, XPS, UV-vis, XRD and BET methods. The silver amount in the nanocomposites decreased in the following order Na-modified zeolite > natural zeolite > H-modified zeolite. Microscopic techniques showed formation of AgNPs of 1–14 nm on natural and Na-modified zeolite, while the diameter of metal particles on H-modified zeolite was 12–42 nm. Diffuse reflectance UV-vis and XPS methods revealed the presence of both silver ions and AgNPs in the materials indicating that partial reduction of Ag+ ions took place upon heating at 400 °C in air. Additionally, antibacterial properties of the nanocomposites were tested against Escherichia coli, and it was found that Ag–containing composites originating from the Na-modified zeolite demonstrated the highest activity.
On Incipient Plasticity of InP Crystal: A Molecular Dynamics Study
Authors: Chrobak Dariusz , Ziółkowski Grzegorz , Chrobak Artur
Published: July 2021

With classical molecular dynamics simulations, we demonstrated that doping of the InP crystal with Zn and S atoms reduces the pressure of the B3→B1 phase transformation as well as inhibits the development of a dislocation structure. On this basis, we propose a method for determining the phenomenon that initiates nanoscale plasticity in semiconductors. When applied to the outcomes of nanoindentation experiments, it predicts the dislocation origin of the elastic-plastic transition in InP crystal and the phase transformation origin of GaAs incipient plasticity.
Long-Term Strength Development of Fly Ash-Based One-Part Alkali-Activated Binders
Authors: Haruna Sani , Mohammed Bashar S. , Wahab Mohamed Mubarak A. , Kankia Mubarak Usman , Amran Mugahed , Gora Abdurra’uf Mukhtar
Published: July 2021

This research aims to study the effect of the dosage of anhydrous sodium metasilicate activator on the long-term properties of fly ash-based one-part alkali-activated binders (OPAAB) cured at ambient conditions. Powdered sodium metasilicate activator was utilized in the range of 8–16% by weight of the fly ash in producing the OPAAB. The properties examined are hardened density, compressive strength, flexural strength, water absorption, efflorescence formation, and microstructural analysis. The experimental result revealed that the binders exhibited excellent long-term strength properties. The compressive strength of the OPAAP is well correlated with its hardened density. The pastes were found to exhibit good soundness characteristics over the long-term. The absorption of water decreases with an increase in the activator dosage from 8–12%, and beyond that, the water absorption relatively remains the same. Field emission scanning electron microscope (FESEM) micrograph revealed uniformly formed solid matrices with the micro-crack present were observed in the samples. The larger pore size promotes the crystallization of the resulting hydrate substances (N, C)-A-S-H gel. The initial dissolution of the OPAAP occurred within the first 30 min. At longer age of curing, mixtures with a higher dosage of powdered activator tend to absorb less water. Strength properties beyond 28 days are considered as the long-term strength.
Construction of a Phytic Acid–Silica System in Wood for Highly Efficient Flame Retardancy and Smoke Suppression
Authors: Chen Zhuoran , Zhang Shaodi , Ding Mengyi , Wang Mingzhi , Xu Xing
Published: July 2021

The intrinsic flammability of wood restricts its application in various fields. In this study, we constructed a phytic acid (PA)–silica hybrid system in wood by a vacuum-pressure impregnation process to improve its flame retardancy and smoke suppression. The system was derived from a simple mixture of PA and silica sol. Fourier transform infrared spectroscopy (FTIR) indicated an incorporation of the PA molecules into the silica network. Thermogravimetric (TG) analysis showed that the system greatly enhanced the char yield of wood from 1.5% to 32.1% (in air) and the thermal degradation rates were decreased. The limiting oxygen index (LOI) of the PA/silica-nanosol-treated wood was 47.3%. Cone calorimetry test (CCT) was conducted, which revealed large reductions in the heat release rate and smoke production rate. The appearance of the second heat release peak was delayed, indicating the enhanced thermal stability of the char residue. The mechanism underlying flame retardancy was analyzed by field-emission scanning electron microscope coupled with energy-dispersive spectroscopy (SEM-EDS), FTIR, and TG-FTIR. The improved flame retardancy and smoke-suppression property of the wood are mainly attributed to the formation of an intact and coherent char residue with crosslinked structures, which can protect against the transfer of heat and mass (flammable gases, smoke) during burning. Moreover, the hybrid system did not significantly alter the mechanical properties of wood, such as compressive strength and hardness. This approach can be extended to fabricate other phosphorus and silicon materials for enhancing the fire safety of wood.
Effect of Titanium and Zirconium Oxide Microparticles on Pro-Inflammatory Response in Human Macrophages under Induced Sterile Inflammation: An In Vitro Study
Authors: Ramenzoni Liza L. , Flückiger Laura B. , Attin Thomas , Schmidlin Patrick R.
Published: July 2021

The wear-debris particles released by shearing forces during dental implant insertion may contribute to inflammatory reactions or osteolysis associated with peri-implantitis by stimulating inflammasome-activation. The study aim was to examine cytotoxic and pro-inflammatory effects of titanium (TiO2) and zirconia (ZrO2) particles in macrophages regarding their nature/particle concentration over time under sterile lipopolysaccharide (LPS) inflammation. Macrophages were exposed to TiO2 and ZrO2 particles (≤5 µm) in cell culture. Dental glass was used as inert control and LPS (1 μg/mL) was used to promote sterile inflammation. Cytotoxicity was determined using MTT assays and cytokine expression of TNF-α, IL-1β and IL-6 was evaluated by qRT-PCR. Data were analyzed using Student’s t-test and ANOVA (p ≤ 0.05). Cytotoxicity was significantly increased when exposed to higher concentrations of glass, TiO2 and ZrO2 (≥107 particles/mL) compared to controls (p ≤ 0.05). Macrophages challenged with TiO2 particles expressed up to ≈3.5-fold higher upregulation than ZrO2 from 12 to 48 h. However, when exposed to LPS, TiO2 and ZrO2 particle-induced pro-inflammatory gene expression was further enhanced (p ≤ 0.05). Our data suggest that ZrO2 particles produce less toxicity/inflammatory cytokine production than TiO2. The present study shows that the biological reactivity of TiO2 and ZrO2 depends on the type and concentration of particles in a time-dependent manner.
Ab-Initio Study of Magnetically Intercalated Platinum Diselenide: The Impact of Platinum Vacancies
Authors: Reyntjens Peter D. , Tiwari Sabyasachi , Van de Put Maarten L. , Sorée Bart , Vandenberghe William G.
Published: July 2021

We study the magnetic properties of platinum diselenide (PtSe2) intercalated with Ti, V, Cr, and Mn, using first-principle density functional theory (DFT) calculations and Monte Carlo (MC) simulations. First, we present the equilibrium position of intercalants in PtSe2 obtained from the DFT calculations. Next, we present the magnetic groundstates for each of the intercalants in PtSe2 along with their critical temperature. We show that Ti intercalants result in an in-plane AFM and out-of-plane FM groundstate, whereas Mn intercalant results in in-plane FM and out-of-plane AFM. V intercalants result in an FM groundstate both in the in-plane and the out-of-plane direction, whereas Cr results in an AFM groundstate both in the in-plane and the out-of-plane direction. We find a critical temperature of <0.01 K, 111 K, 133 K, and 68 K for Ti, V, Cr, and Mn intercalants at a 7.5% intercalation, respectively. In the presence of Pt vacancies, we obtain critical temperatures of 63 K, 32 K, 221 K, and 45 K for Ti, V, Cr, and Mn-intercalated PtSe2, respectively. We show that Pt vacancies can change the magnetic groundstate as well as the critical temperature of intercalated PtSe2, suggesting that the magnetic groundstate in intercalated PtSe2 can be controlled via defect engineering.
Detection and Identification of Defects in 3D-Printed Dielectric Structures via Thermographic Inspection and Deep Neural Networks
Authors: Szymanik Barbara , Psuj Grzegorz , Hashemi Maryam , Lopato Przemyslaw
Published: July 2021

In this paper, we propose a new method based on active infrared thermography (IRT) applied to assess the state of 3D-printed structures. The technique utilized here—active IRT—assumes the use of an external energy source to heat the tested material and to create a temperature difference between undamaged and defective areas, and this temperature difference is possible to observe with a thermal imaging camera. In the case of materials with a low value of thermal conductivity, such as the acrylonitrile butadiene styrene (ABS) plastic printout tested in the presented work, the obtained temperature differences are hardly measurable. Hence, the proposed novel IRT method is complemented by a dedicated algorithm for signal analysis and a multi-label classifier based on a deep convolutional neural network (DCNN). For the initial testing of the presented methodology, a 3D printout made in the shape of a cuboid was prepared. One type of defect was tested—surface breaking holes of various depths and diameters that were produced artificially by inclusion in the printout. As a result of examining the sample via the IRT method, a sequence of thermograms was obtained, which enabled the examination of the temporal representation of temperature variation over the examined region of the material. First, the obtained signals were analysed using a new algorithm to enhance the contrast between the background and the defect areas in the 3D print. In the second step, the DCNN was utilised to identify the chosen defect parameters. The experimental results show the high effectiveness of the proposed hybrid signal analysis method to visualise the inner structure of the sample and to determine the defect and size, including the depth and diameter.
The Rise of the Xenes: From the Synthesis to the Integration Processes for Electronics and Photonics
Authors: Grazianetti Carlo , Martella Christian
Published: July 2021

The recent outcomes related to the Xenes, the two-dimensional (2D) monoelemental graphene-like materials, in three interdisciplinary fields such as electronics, photonics and processing are here reviewed by focusing on peculiar growth and device integration aspects. In contrast with forerunner 2D materials such as graphene and transition metal dichalcogenides, the Xenes pose new and intriguing challenges for their synthesis and exploitation because of their artificial nature and stabilization issues. This effort is however rewarded by a fascinating and versatile scenario where the manipulation of the matter properties at the atomic scale paves the way to potential applications never reported to date. The current state-of-the-art about electronic integration of the Xenes, their optical and photonics properties, and the developed processing methodologies are summarized, whereas future challenges and critical aspects are tentatively outlined.
Progress and Challenges in Industrially Promising Chemical Vapour Deposition Processes for the Synthesis of Large-Area Metal Oxide Electrode Materials Designed for Aqueous Battery Systems
Authors: Vernardou Dimitra
Published: July 2021

The goal of the battery research community is to reach sustainable batteries with high performance, meaning energy and power densities close to the theoretical limits, excellent stability, high safety, and scalability to enable the large-scale production of batteries at a competitive cost. In that perspective, chemical vapour deposition processes, which can operate safely under high-volume conditions at relatively low cost, should allow aqueous batteries to become leading candidates for energy storage applications. Research interest and developments in aqueous battery technologies have significantly increased the last five years, including monovalent (Li+, Na+, K+) and multivalent systems (Mg2+, Zn2+, Al3+). However, their large-scale production is still somewhat inhibited, since it is not possible to get electrodes with robust properties that yield optimum performance of the electrodes per surface area. In this review paper, we present the progress and challenges in the growth of electrodes through chemical vapour deposition at atmospheric pressure, which is one procedure that is proven to be industrially competitive. As battery systems attract the attention of many researchers, this review article might help those who work on large-scale electrical energy storage.
One-Abutment One-Time Effect on Peri-Implant Marginal Bone: A Prospective, Controlled, Randomized, Double-Blind Study
Authors: Moreira Filipe , Rocha Salomão , Caramelo Francisco , Tondela João P.
Published: July 2021

Objective: To evaluate the peri-implant hard tissue change at 6 and 12 months after implant placement between definitive abutment placed at the same time of implant surgery, never removing it, and healing abutment disconnected and reconnected three times until the placement of the final rehabilitation. Material and methods: Each partial edentulous patient could receive between 1 and 4 platform-switched implants in the posterior regions. If the implants had primary stability—implant stability quotient (ISQ) equal to or greater than 50, they were randomized to the test group with the abutment inserted at the same time of implant placement (DA) or to the control group, receiving a healing abutment (PA). At 6 and 12 months after surgery, data related with vertical bone level changes (primary outcome) and other clinical parameters (implant mobility, bleeding on probing, probing depth, plaque index) were assessed. Results: 53 implants were included in the trial and completed 12 months follow-up (overall survival rate: 100%). All implants achieved primary stability, with an average ISQ value of 80.9 on the day of surgery. From surgery to 6 months, the mean bone loss was 0.14 ± 0.18 mm for the DA group and 0.23 ± 0.29 mm for the PA group, without statistical significance difference. Between 6 and 12 months, the mean bone loss was 0.14 ± 0.21 mm for the DA group and 0.21 ± 0.27 mm for the PA group, also without statistical significance between the two groups. There were no statistically significant differences (p = 0.330) in total bone loss after 12 months between the control and the study groups. Conclusions: The one abutment one time protocol has at least an equivalent effect on the peri-implant bone level changes when compared with the use of healing abutments that are disconnected and reconnected at least three times.
Fluorescent Materials for Monitoring Mitochondrial Biology
Authors: Chu Yeonjeong , Park Jisoo , Kim Eunha , Lee Sanghee
Published: July 2021

Mitochondria play important roles in diverse cellular processes such as energy production, cellular metabolism, and apoptosis to promote cell death. To investigate mitochondria-associated biological processes such as structure, dynamics, morphological change, metabolism, and mitophagy, there exists a continuous demand for visualizing and monitoring techniques elucidating mitochondrial biology and disease-relevancy. Due to the advantages of high sensitivity and practicality, fluorescence phenomena have been most widely used as scientific techniques for the visualization of biological phenomena and systems. In this review, we briefly overview the different types of fluorescent materials such as chemical probes, peptide- or protein-based probes, and nanomaterials for monitoring mitochondrial biology.
Combustion Synthesis of Aluminum Oxynitride in Loose Powder Beds
Authors: Wilmański Alan , Zarzecka-Napierała Magdalena , Pędzich Zbigniew
Published: July 2021

This paper describes combusting loose powder beds of mixtures of aluminum metal powders and aluminum oxide powders with various grain sizes under various nitrogen pressure. The synthesis conditions required at least 20/80 weight ratio of aluminum metal powder to alumina powder in the mix to reach approximately 80 wt% of γ-AlON in the products. Finely ground fused white alumina with a mean grain size of 5 μm was sufficient to achieve results similar to very fine alumina with 0.3 μm grains. A lower nitrogen pressure of 1 MPa provided good results, allowing a less robust apparatus to be used. The salt-assisted combustion synthesis upon addition of 10 wt% of ammonium nitrite resulted in a slight increase in product yield and allowed lower aluminum metal powder content in mixes to be ignited. Increasing the charge mass five times resulted in a very similar γ-AlON yield, providing a promising technology for scaling up. Synthesis in loose powder beds could be utilized for effective production of relatively cheap and uniform AlON powder, which could be easily prepared for forming and sintering without intensive grounding and milling, which usually introduce serious contamination.
Optically Controlled Supercapacitors: Functional Active Carbon Electrodes with Semiconductor Particles
Authors: Grebel Haim
Published: July 2021

Supercapacitors, S-C—capacitors that take advantage of the large capacitance at the interface between an electrode and an electrolyte—have found many short-term energy applications. The parallel plate cells were made of two transparent electrodes (ITO), each covered with a semiconductor-embedded, active carbon (A-C) layer. While A-C appears black, it is not an ideal blackbody absorber that absorbs all spectral light indiscriminately. In addition to a relatively flat optical absorption background, A-C exhibits two distinct absorption bands: in the near-infrared (near-IR and in the blue. The first may be attributed to absorption by the OH− group and the latter, by scattering, possibly through surface plasmons at the pore/electrolyte interface. Here, optical and thermal effects of sub-μm SiC particles that are embedded in A-C electrodes, are presented. Similar to nano-Si particles, SiC exhibits blue band absorption, but it is less likely to oxidize. Using Charge-Discharge (CD) experiments, the relative optically related capacitance increase may be as large as ~34% (68% when the illuminated area is taken into account). Capacitance increase was noted as the illuminated samples became hotter. This thermal effect amounts to <20% of the overall relative capacitance change using CD experiments. The thermal effect was quite large when the SiC particles were replaced by CdSe/ZnS quantum dots; for the latter, the thermal effect was 35% compared to 10% for the optical effect. When analyzing the optical effect one may consider two processes: ionization of the semiconductor particles and charge displacement under the cell’s terminals—a dipole effect. A model suggests that the capacitance increase is related to an optically induced dipole effect.
Analysis of Selected Methods Use for Calculation of the Coefficients of Adsorption Isotherms and Simplified Equations of Adsorption Dynamics with the Use of IZO Application
Authors: Piekarski Jacek , Ignatowicz Katarzyna , Dąbrowski Tomasz
Published: July 2021

The purpose of this paper is to present the IZO application that calculates and visualizes coefficients of adsorption isotherms according to Freundlich, Langmuir, and BET in a classic and linear system, in a simple communicative way. The application also calculates the working time of the adsorption bed based on the transformation of the mass balance equation, and according to the Zuchowicki, Zabieziński, Tichonow, and the Bohart-Adams equations. The laboratory tests of the adsorption process of leachate from a municipal landfill on selected active coals ORGANOSORB 10, DESOTEK, and BA-10, were conducted to check the program for accuracy. Results of tests confirm that the linearization method of the calculation of adsorption isotherms coefficients, used in the IZO application, gives sufficient accuracy and may be used as an alternative of, e.g., the nonlinear estimation method.
Marine-Derived Compounds with Anti-Alzheimer’s Disease Activities
Authors: Hafez Ghoran Salar , Kijjoa Anake
Published: July 2021

Alzheimer’s disease (AD) is an irreversible and progressive brain disorder that slowly destroys memory and thinking skills, and, eventually, the ability to perform simple tasks. As the aging population continues to increase exponentially, AD has become a big concern for society. Therefore, neuroprotective compounds are in the spotlight, as a means to tackle this problem. On the other hand, since it is believed—in many cultures—that marine organisms in an individual diet cannot only improve brain functioning, but also slow down its dysfunction, many researchers have focused on identifying neuroprotective compounds from marine resources. The fact that the marine environment is a rich source of structurally unique and biologically and pharmacologically active compounds, with unprecedented mechanisms of action, marine macroorganisms, such as tunicates, corals, sponges, algae, as well as microorganisms, such as marine-derived bacteria, actinomycetes, and fungi, have been the target sources of these compounds. Therefore, this literature review summarizes and categorizes various classes of marine-derived compounds that are able to inhibit key enzymes involved in AD, including acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), β-secretase (BACE-1), and different kinases, together with the related pathways involved in the pathogenesis of AD. The compounds discussed herein are emerging as promising anti-AD activities for further in-depth in vitro and in vivo investigations, to gain more insight of their mechanisms of action and for the development of potential anti-AD drug leads.