UV-shielding by a polyurethane/f-Oil fly ash-CeO2 protective coating

A waste material called oil fly ash (OFA) was acid-functionalized, yielding f-OFA-COOH, which was then reacted with cerium oxide (CeO₂) to make CeO₂-functionalized OFA, or f-OFA-CeO₂. Pristine OFA and f-OFA-CeO₂ were used to make waterborne polyurethane (WBPU) dispersions, referred to as WBPU/OFA and WBPU/f-OFA-CeO₂, respectively, with defined OFA and f-OFA-CeO₂ content. All the dispersions were applied to mild steel as organic coatings to evaluate their protective properties, such as their hydrophobicity, adhesive strength and UV-shielding resistance. These protective properties varied based on the OFA and f-OFA-CeO₂ content. The highest water contact angle, minimum water swelling and maximum adhesive strength were found using WBPU/f-OFA-CeO₂-20 coating (using 2.00 wt% f-OFA-CeO₂), which also showed the maximum ultraviolet (UV) absorption via UV–vis spectroscopy analysis. This UV shielding result also matched field test results, as that coating was found to exhibit the lowest UV degradation near a marine atmosphere, as shown by X-ray photoelectron spectroscopy (XPS) analysis. The least affected hydrophobicity was also recorded for the sample with the WBPU/f-OFA-CeO₂-20 coating.     

The Association between Gut Microbiota and Osteoarthritis: Does the Disease Begin in the Gut?

Some say that all diseases begin in the gut. Interestingly, this concept is actually quite old, since it is attributed to the Ancient Greek physician Hippocrates, who proposed the hypothesis nearly 2500 years ago. The continuous breakthroughs in modern medicine have transformed our classic understanding of the gastrointestinal tract (GIT) and human health. Although the gut microbiota (GMB) has proven to be a core component of human health under standard metabolic conditions, there is now also a strong link connecting the composition and function of the GMB to the development of numerous diseases, especially the ones of musculoskeletal nature. The symbiotic microbes that reside in the gastrointestinal tract are very sensitive to biochemical stimuli and may respond in many different ways depending on the nature of these biological signals. Certain variables such as nutrition and physical modulation can either enhance or disrupt the equilibrium between the various species of gut microbes. In fact, fat-rich diets can cause dysbiosis, which decreases the number of protective bacteria and compromises the integrity of the epithelial barrier in the GIT. Overgrowth of pathogenic microbes then release higher quantities of toxic metabolites into the circulatory system, especially the pro-inflammatory cytokines detected in osteoarthritis (OA), thereby promoting inflammation and the initiation of many disease processes throughout the body. Although many studies link OA with GMB perturbations, further research is still needed.     

Hierarchical polymer nanocomposite coating material for 316L SS implants: Surface and electrochemical aspects of PPy/f-CNTs coatings

Biocompatible nanocomposite coatings can be synthesized to offer improved surface properties for biomaterials and biomedical implants. Nanocomposite coatings containing polypyrrole (PPy) matrix reinforced with functionalized multi-wall carbon nanotubes (f-CNTs) were deposited on 316L SS substrates using electrochemical route. FT-IR, XRD, SEM, and TEM were employed to characterize the nanocomposite microstructure. High resolution imaging showed relatively uniform dispersion of the CNTs in the nanocomposite with a typical tubular structure. Micro-indentation tests revealed improvement in the hardness of the PPy/CNTs coatings. Measurement of the contact angle indicated enhanced surface wettability of the nanocomposite coatings. The corrosion behavior of 316L SS samples coated with PPy/CNTs was studied in SBF medium. The corrosion potential and the breakdown potential of coated 316L SS substrates shifted to more noble values as compared to uncoated 316L SS samples. The results suggest that incorporating CNTs as reinforcements in PPy coatings can provide enhanced properties in terms of surface hardness, biocompatibility, and corrosion resistance.     

Size effect and order–disorder phase transition in MgAl<Subscript>2</Subscript>O<Subscript>4</Subscript>: synthesized by co-precipitation method

We report on the size effect and order–disorder phase transitions in MgAl₂O₄ system synthesized by chemical co-precipitation method. The prepared samples were sintered at various temperatures (in steps of 200 °C). Initially, the order–disorder phase evolution of the cubic spinel aluminates were analyzed by powder X-ray diffraction and UV-absorbance spectral analysis. The optical band gap was calculated from UV–DRS absorbance spectra. Also, the grain size of the sintered aluminates was calculated by high resolution scanning electron microscopy through surface morphological image analysis and discussed. Moreover, the particle size was calculated by using transmission electron microscopy. The stretching and bending mode of tetrahedral and octahedral coordinates for vibration modes of cations were studied through Fourier transform infrared spectral analysis. In addition, the cation distributions in the prepared samples were carried out by solid-state nuclear magnetic resonance spectroscopic measurement and analyses. The frequency dispersive behavior of dielectric constant was analyzed at room temperature for the synthesized samples using impedance analyzer. The observed results are discussed and reported.     

Fabrication and Characterization of Nanostructured AACVD Thin Films on 316L SS as Surface Protective Layers in Simulated Body Fluid

Metallurgical and Materials Transactions A - The surface of implant materials is one of the most significant factors for controlling the interaction between biomaterials and bone tissues. Hence,...     

Thermal treatment effect on the surface and in vitro corrosion characteristics of arc deposited TiN coating on Ti alloy for orthopedic applications

The influence of post thermal treatment at (500,600,700, and 800 °C) of cathodic arc physical vapor deposited TiN coated Ti6Al4V (Ti64) alloy was studied for orthopedic uses. The structure, surface characteristics, mechanical properties of coated and treated samples was investigated using XRD, FESEM/EDX, XPS, AFM, and micro indentation. The influence of post heat treatment on the in vitro corrosion-resistant behavior in a physiological medium was assessed by linear polarization, electrochemical frequency modulation, and impedance spectroscopic measurements. The results showed that a TiN layer of 5 ± 0.15 μm was formed over Ti64 alloy with higher microhardness and modulus compared to the bare substrate. The rutile TiO₂ oxide phase begins to form with the TiN at 500 °C, the TiO₂ phase intensity increased with the temperature, and the TiO₂ upper layer over the TiN film was formed at 700 and 800 °C. The microhardness and modulus were increased at 500 °C due to enhanced crystallinity of TiN, then decreased with increasing the temperature due to the internal stress relaxation of TiN and formation of the TiO₂ phase. The treated samples showed higher resistance to plastic deformation compared to the TiN coated and uncoated alloy. The sample treated at 500 °C showed the highest hardness, modulus, and resistance to plastic deformation. The obtained in vitro corrosion results indicated that post thermal treatment improves the corrosion resistance of TiN coated.     

5 Fluorouracil‐loaded biosynthesised gold nanoparticles for the in vitro treatment of human pancreatic cancer cell

In this study, green synthesis of gold nanoparticles (AuNPs) was performed by a sunlight irradiation method using the Borassus flabellifer fruit extract as a reducing agent. 5‐Fluorouracil (5‐FU)‐loaded GG capped AuNPs (5FU‐G‐AuNPs) was prepared. The nanoparticles was further characterised by UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, and XRD. The MTT assay results showed the suitability 5‐FU‐G‐AuNPs. In this study, 5‐FU‐G‐AuNPs exhibited potential cytotoxic and apoptotic effects on (MiaPaCa‐2) cell line.Inspec keywords: gold, biochemistry, X‐ray diffraction, nanofabrication, biomedical materials, transmission electron microscopy, toxicology, electrokinetic effects, particle size, nanoparticles, cancer, visible spectra, cellular biophysics, ultraviolet spectra, nanomedicine, patient treatment, organic compoundsOther keywords: 5FU‐G‐AuNPs, suitability 5‐FU‐G‐AuNPs, human pancreatic cancer cell, green synthesis, sunlight irradiation method, 5‐Fluorouracil‐loaded GG, in vitro treatment, 5 fluorouracil‐loaded biosynthesised gold nanoparticles, borassus flabellifer fruit extract, reducing agent, UV‐visible spectra, particle size analysis, zeta potential, SAED, HRTEM, XRD, MTT assay, apoptotic effects, cytotoxic effects, MiaPaCa‐2 cell line, Au