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Aluminium (Al) is reported to promote beta amyloid (Aß) aggregation, free radical production and disturb acetylcholine metabolism leading to cognitive dysfunction that are strongly associated with Alzheimer's disease (AD). Here we utilized synchrotron Fourier transform infrared microspectroscopy (sFTIRM) to analyse the fine structure of proteins and lipids in the rat cortical brain tissues in response to AlCl3 toxicity and Lepidium sativum (LS) treatment after 42 and 65 days. For statistical analysis, we used principal component analysis (PCA). Our results showed profusion of gauche rotomers form in membrane lipid acyl chains that increases the membrane fluidity and disorder only in AD group indicated by the detected sνCH2 band shift to higher frequency. All half bands width (HBW) values of the decomposed amide I band showed marked decrease in AD group compared to the other tested groups, together with an increase in the amounts of ß-sheets (1641 cm-1) protein and random coil structure (1654 cm-1). These were indicated by a drastic increase in the percentage areas ratios of (1638 cm-1/1654 cm-1) and (1641 cm-1/1654 cm-1) that may be attributed to a stronger the hydrogen bonds that stabilize the protein conformational structure and/or the increase of the ß-strand length due to misfolded Aß formation in response to Al toxicity through transit phase/phases dominated by random coil structure. In curative group, LS treatment reversed these changes and restored the protein and lipid integrities. To conclude, sFTIRM is a powerful tool that shed light on the biomolecular structure of AD-like cortical brain tissue and considered the therapeutic potential of LS as a promising natural AD treatment.

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Aluminium (Al) is reported to promote free radical production, decrease the antioxidant enzyme status and disturb the enzyme activity involved in acetylcholine metabolism leading to cognitive dysfunction that are strongly associated with Alzheimer's disease (AD) pathogenesis. This work aimed at investigating the effect of Al-toxicity on synaptosomal membrane biophysical properties and lipid peroxidation during 65 days. We utilized ATR-IR spectroscopy to study the changes in membrane biochemical structure and biophysical properties of isolated rat cortical synaptosomes, and EPR spin trapping and labeling to follow NADPH oxidase activity and changes of membrane order parameter, respectively. The results showed increase in membrane fluidity and disorder in early 21d of AlCl3 treatment, while after 42d the membrane rigidity, packing, and order increased. The late (65d) an increase in the amount of unsaturated fatty acids, the accumulation of lipid peroxide end products, and ROS production were detected in rat cortex synaptosomes mediated by Al toxicity and oxidative stress (OS). A dramatic increase was also detected in Ca2+ level, synaptic membrane polarity, and EPR-detected order S-parameter. These outcomes strongly suggest that the synaptosomal membrane phospholipids underwent free radical attacks mediated by AlCl3 due to greater NOX activity, and the release of synaptic vesicles into synaptic cleft might be hindered. The adopted spectroscopic techniques have shed light on the biomolecular structure and membrane biophysical changes of isolated cortical synaptosomes for the first time, allowing researchers to move closer to a complete understanding of pathological tissues.

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INTRODUCTION: Thermo-responsive hydrogels are promising biomedical systems as their gelation is triggered by temperature changes. Greenly synthesized noble metallic nanoparticles are a growing research area assessing their potential applications in nanomedicine. MATERIALS AND METHODS: Chitosan/phosphate thermosensitive gels were successfully achieved. The developed composite scaffolds were functionalized with the greenly synthesized Ag or Ag@Pd targeting improved bactericidal activity and biocompatibility performance. The physicochemical characterization was assessed through TGA, DSC, FESEM, HRTEM, XRD and FTIR. Bactericidal activities were tested against gram- positive Staphylococcus aureus and gram-negative Pseudomonas aeruginosa. Their biodegradability upon DMEM immersion was followed up to seven days through measuring ionic concentrations of Ca, P, Ag and Pd successively. KEY FINDINGS: The newly developed phosphatic layers over the scaffold surfaces post-immersion assessed their osteogenic ability. Further, their promising and differentiated bactericidal activities due to the noble metals incorporation were proved. Cytotoxicity assessment demonstrated their high biocompatibility since no toxic effect was recorded. SIGNIFICANCE: Consequently, they can be successfully and directly applied in biomedical and dental surgeries.

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We present terahertz spectroscopy study on spherical nanoparticles powder mixture of aluminum, alumina, and MWCNTs induced by surface mechanical attrition treatment (SMAT) of aluminum substrates. Surface alloying of AL, Al2O3 0.95% and MWCNTs 0.05% powder mixture was produced during SMAT process, where a compact surface layer of about 200 µm due to ball bombardment was produced from the mixture. Al2O3 alumina powder played a significant role in MWCNTs distribution on surface, those were held in deformation surface cites of micro-cavities due to SMAT process of Al. The benefits are the effects on resulted optical properties of the surface studied at the terahertz frequency range due to electrical isolation confinement effects and electronic resonance disturbances exerted on Al electronic resonance at the same range of frequencies. THz acoustic phonon around 0.53-0.6THz (17-20cm-1) were observed at ambient conditions for the spherical nanoparticles powder mixture of Al, Al2O3 and MWCNTs. These results suggested that the presence of Al2O3 and MWCNTs during SMAT process leads to the optically detection of such acoustic phonon in the THz frequency range.