Ti–Au intermetallic-based material systems are being extensively studied as next-generation thin film coatings to extend the lifetime of implant devices. These coatings are being developed for ...application to the articulating surfaces of total joint implants and, therefore, must have excellent biocompatibility combined with superior mechanical hardness and wear resistance. However, these key characteristics of Ti–Au coatings are heavily dependent upon factors such as the surface properties and temperature of the underlying substrate during thin film deposition. In this work, Ti3Au thin films were deposited by magnetron sputtering on both glass and Ti6Al4V substrates at an ambient and elevated substrate temperature of 275 °C. These films were studied for their mechanical properties by the nanoindentation technique in both variable load and fixed load mode using a Berkovich tip. XRD patterns and cross-sectional SEM images detail the microstructure, while AFM images present the surface morphologies of these Ti3Au thin films. The biocompatibility potential of the films is assessed by cytotoxicity tests in L929 mouse fibroblast cells using Alamar blue assay, while leached ion concentrations in the film extracts are quantified using ICPOEMS. The standard deviation for hardness of films deposited on glass substrates is ∼4 times lower than that on Ti6Al4V substrates and is correlated with a corresponding increase in surface roughness from 2 nm for glass to 40 nm for Ti6Al4V substrates. Elevating substrate temperature leads to an increase in film hardness from 5.1 to 8.9 GPa and is related to the development of a superhard β phase of the Ti3Au intermetallic. The standard deviation of this peak mechanical hardness value is reduced by ∼3 times when measured in fixed load mode compared to the variable load mode due to the effect of nanoindentation tip penetration depth. All tested Ti–Au thin films also exhibit excellent biocompatibility against L929 fibroblast cells, as viability levels are above 95% and leached Ti, Al, V, and Au ion concentrations are below 0.1 ppm. Overall, this work demonstrates a novel Ti3Au thin film system with a unique combination of high hardness and excellent biocompatibility with potential to be developed into a new wear-resistant coating to extend the lifetime of articulating total joint implants.
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IJS, KILJ, NUK, PNG, UL, UM
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•A new approach to test inflammatory-induced corrosion of biomedical Ti was presented.•Corrosion was monitored in the PBS + H2O2 in the real-time using in situ AFM and AESEC.•Both ...oxide film growth and dissolution contributes to corrosion of commercially pure Ti.•Oxide film growth in PBS + H2O2 is suppressed for Ti-29Nb-13Ta-4.6Zr (TNTZ).•Roughness rather than chemical composition determines oxide film growth on TNTZ in PBS + H2O2.
This study offers a new approach to analyze surface behavior of titanium biomaterials during their exposure to the H2O2-enriched fluid which simulates post-operative inflammatory conditions. In this work in situ AFM and AESEC tests were exploited to study the origin of initial inflammatory-induced degradation for commercially pure Ti (CP-Ti) and Ti-29Nb-13Ta-4.6Zr (TNTZ) alloy. Overall results indicate that initial interaction between H2O2 and TNTZ surface results only in dissolution of the alloy, while for CP-Ti both oxide formation and dissolution give important contribution to the degradation process. Proposed methodology yields insight into the origin of corrosion properties registered during standard electrochemical tests that are used to evaluate biomaterials.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
This study primarily focuses on the environmental assessment of the Marchica lagoon ecosystem. The objective of this research was to determine the ecological effects associated with the development, ...especially the opening of a new inlet, of the Marchica lagoon on the physicochemical parameters of its liquid phase, geochemical characteristics, as well as the distribution and content of sedimentary substrates. Two sampling campaigns were conducted in February 2023 and May 2023 within the Marchica lagoon to perform a detailed characterization of water physicochemical parameters, including temperature, pH, salinity, turbidity, dissolved oxygen, and chlorophyll. Additionally, a sedimentological and geochemical analysis of collected sediment samples was performed. The results highlight significant variations in these parameters, both in terms of location and temporal variations. Results of the sedimentological and geochemical study of the sediments are also included for a comprehensive understanding of the impact of management development on the lagoon's ecosystem.
This paper reports recent lattice characterization results obtained at the National Synchrotron Light Source II (NSLS-II) storage ring, conducted without reliance on a lattice model. A pair of beam ...position monitors (BPMs) with bunch-by-bunch (B×B) resolution, were recently installed in a section of the storage ring free of magnetic fields. The new BPM pair measured the beam, or bunch’s transverse Poincaré map precisely after the beam was excited. Linear one-turn-matrices (OTM) were then derived, and from these, the 4-dimensional coupled Twiss parameters were extracted at the locations of the BPM pair. By normalizing beam oscillation amplitudes with the Twiss parameters, the global action-variables were obtained. These action-variables facilitated the measurement of the local Twiss parameters observed by other BPMs independent on lattice model. This method is general, and particularly useful in certain scenarios such as a round beam mode in a diffraction-limited light source ring. We applied it to assess both weakly and strongly coupled lattices at the NSLS-II ring. Through analysis of the strongly coupled lattice, the quadrupole tilt errors were estimated to be less than 400 μrad. Utilizing the BPMs’ B×B resolution, for the first time we observed the variations of the linear lattice along a long bunch-train.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In India, fish roes are generally considered worthless garbage and disposed of without recovering the valuable molecules, creating environmental and disposal problems. The present investigation aimed ...to optimize the extraction conditions, partial purification, and characterization of sialoglycoproteins (RRSGP) from Labeo rohita (rohu) roes. RSM generated optimum conditions for maximum RRSGP (70.49 %) extraction, which were 1.25 M NaCl, 1:32.5(w/v) solid-to-liquid ratio, 47.5 °C temperature, and 3 h time. Further, sialoglycoproteins from RRSGPs were partially purified, and result revealed that obtained peak-1 (PRRSGP) using QFF anion exchange chromatography exhibited higher glycoprotein and sialic acid content (p < 0.05). SDS-PAGE pattern of PRRSGP presented dominant bands of 97 kDa and 27 kDa glycoproteins. FTIR spectrum of PRRSGP confirmed the presence of glycated proteins. HPLC analysis revealed that PRRSGP consists of Neu5Ac. Furthermore, β-elimination reaction elucidated that PRRSGP contained N-glycosidic linkage. PRRSGP exhibited tyrosine and glutamate as primary amino acids. Glycan part of PRRSGP presented mannose and N-acetyl galactosamine as dominant neutral and amino sugar, respectively. Furthermore, PRRSGP exhibited antioxidant activity with EC50 value for DPPH (8.79 mg/ml) and ABTS (2.21 mg/ml). Besides, RRSGP displayed better protein solubility, foaming, and emulsion properties. Therefore, rohu roes are potential source of sialoglycoproteins that can be recovered and used as bio-functional ingredients in food and nutraceutical applications.
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•Sodium chloride salt promoted sialoglycoprotein (RRSGP) extraction from rohu roes.•Optimum conditions for RRSGP extraction (70.49 %) were 1.25 M NaCl, 1:32.5 S/L and 3 h.•Partially purified RRSGP are N-glycosylated with Neu5Ac as the type of sialic acid.•RRSGP exhibited better antioxidant and functional properties.•Rohu roes can be a promising source for sialoglycoproteins extraction.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Age of Information (AoI) is a performance metric that captures the freshness of the information from the perspective of the destination. The AoI measures the time that elapsed since the generation of ...the packet that was most recently delivered to the destination. In this paper, we consider a single-hop wireless network with a number of nodes transmitting time-sensitive information to a Base Station and address the problem of minimizing the Expected Weighted Sum AoI of the network while simultaneously satisfying timely-throughput constraints from the nodes. We develop three low-complexity transmission scheduling policies that attempt to minimize AoI subject to minimum throughput requirements and evaluate their performance against the optimal policy. In particular, we develop a randomized policy, a Max-Weight policy and a Whittle's Index policy, and show that they are guaranteed to be within a factor of two, four and eight, respectively, away from the minimum AoI possible. In contrast, simulation results show that Max-Weight outperforms the other policies, both in terms of AoI and throughput, in every network configuration simulated, and achieves near optimal performance.
The goal of this study was to characterize changes in components and toxicological properties of PM2.5 during the nationwide 2019-Coronavirus (COVID-19) lockdown restrictions in Milan, Italy. ...Time-integrated PM2.5 filters were collected at a residential site in Milan metropolitan area from April 11th to June 3rd at 2020, encompassing full-lockdown (FL), the followed partial-lockdown (PL2), and full-relaxation (FR) periods of COVID-19 restrictions. The collected filters were analyzed for elemental and organic carbon (EC/OC), water-soluble organic carbon (WSOC), individual organic species (e.g., polycyclic aromatic hydrocarbons (PAHs), and levoglucosan), and metals. According to online data, nitrogen dioxide (NO2) and benzene (C6H6) levels significantly decreased during the entire COVID-19 period compared to the same time span in 2019, mainly due to the government-backed shutdowns and curtailed road traffic. Similarly, with a few exceptions, surrogates of tailpipe emissions (e.g., traffic-associated PAHs) as well as re-suspended road dust (e.g., Fe, Mn, Cu, Cr, and Ti) were relatively lower during FL and PL2 periods in comparison with year 2019, whereas an increasing trend in mass concentration of mentioned species was observed from FL to PL2 and FR phases due to the gradual lifting of lockdown restrictions. In contrast, comparable concentrations of ambient PM2.5 and black carbon (BC) between lockdown period and the same time span in 2019 were attributed to the interplay between decreased road traffic and elevated domestic biomass burning as a result of adopted stay-home strategies. Finally, the curtailed road traffic during FL and PL2 periods led to ~25% drop in the PM2.5 oxidative potential (measured via 2′,7′-dichlorodihydrofluorescein (DCFH) and dithiothreitol (DTT) assays) with respect to the FR period as well as the same time span in 2019. The results of this study provide insights into the changes in components and oxidative potential of PM2.5 in the absence of road traffic during COVID-19 restrictions.
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•Chemical and toxicological characteristics of PM2.5 were determined during COVID-19 pandemic in the Milan metropolitan area.•Ambient levels of NO2, C6H6, OC, and redox-active metals decreased during COVID-19 period.•PM2.5 and BC did not undergo significant changes in COVID-19 lockdown due to enhanced residential heating activities.•PM2.5 oxidative potential decreased during the COVID-19 lockdown as a result of curtailed traffic.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Composite materials are gaining popularity because of their superior properties compared to traditional materials. However, further improvements can be made by adding nanoparticles as nanocoating and ...nanofiller with the composite materials for different industrial applications. In this study, a Kevlar fibre mat has been coated by nanoparticles. In addition to this, different nanofillers have also been added. Various mechanical, physical, morphological, and thermal characterization techniques have been performed to characterize the synthesized composites. Five different samples were made where graphenenanocomposites showed the highest mechanical properties in hardness, tensile, bending, and compression. Around 15%, 35%, 120% and 170% improvement was obtained in hardness, tensile, bending and compression due to graphene incorporation compared to the composite without nanopartilces reinforcement.The minimum void fraction was obtained from the sample prepared without nanoparticles, which was 2.9%. The nanocoated surfaces of the composites were smoother and had a better surface finish with the uniform distribution of nanoparticles. The addition of graphene and other nanoparticles increased the crystallinity and binding energy of the composites. Fourier Transformed Infrared Spectroscopy analysis identified the presence of different functional groups. The addition of nanoparticles increased the thermal stability significantly.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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