Malaysian Propolis and Metformin Synergistically Mitigate Kidney Oxidative Stress and Inflammation in Streptozotocin-Induced Diabetic Rats

Diabetic nephropathy is reported to occur as a result of the interactions between several pathophysiological disturbances, as well as renal oxidative stress and inflammation. We examined the effect of Malaysian propolis (MP), which has anti-hyperglycemic, antioxidant and anti-inflammatory properties, on diabetes-induced nephropathy. Diabetic rats were either treated with distilled water (diabetic control (DC) group), MP (300 mg/kg b.w./day), metformin (300 mg/kg b.w./day) or MP + metformin for four weeks. We found significant increases in serum creatinine, urea and uric acid levels, decreases in serum sodium and chloride levels, and increase in kidney lactate dehydrogenase activity in DC group. Furthermore, malondialdehyde level increased significantly, while kidney antioxidant enzymes activities, glutathione level and total antioxidant capacity decreased significantly in DC group. Similarly, kidney immunoexpression of nuclear factor kappa B, tumor necrosis factor-α, interleukin (IL)-1β and caspase-3 increased significantly, while IL-10 immunoexpression decreased significantly in DC group relative to normal control group. Histopathological observations for DC group corroborated the biochemical data. Intervention with MP, metformin or both significantly mitigated these effects and improved renal function, with the best outcome following the combined therapy. MP attenuates diabetic nephropathy and exhibits combined beneficial effect with metformin.     

High-Q and temperature stable photonic biosensor based on grating waveguides

Optical and Quantum Electronics - Evaluation of polarization control by polarization attractor based on stimulated Raman scattering in optical fiber is presented. Performed simulations are...     

A Novel ICP Torch with Conical Geometry

Plasma Chemistry and Plasma Processing - This paper presents the development of a novel radio-frequency inductively coupled plasma (RF-ICP) torch. Computer simulations and experiments were employed...     

Bifunctional metal-free KAUST Catalysis Center 1 (KCC-1) as highly active catalyst for syngas production via methane partial oxidation

The metal-free KAUST Catalysis Center 1 (KCC-1) was synthesized through microemulsion method with microwave assistance and was assessed for methane partial oxidation (MPO) under various operating conditions. The electronic spin resonance spectroscopy, pyridine-probed infrared spectroscopy, and temperature-programmed desorption of oxygen measurement indicated that the concentration of BrØnsted acid sites and oxygen vacancies in KCC-1 were at least 2-fold higher than its counterparts, which benefited MPO activity via the promotion of adsorption and dissociation of gaseous reactants. The principal species detected by post-reaction X-ray photoelectron spectroscopy (XPS) was surface-adsorbed oxygen species; its relative percentages among all oxygen species reduced in the order spent KCC-1 (77.1%) > spent MCM-41 (Mobil Composition of Matter number 41; 41.4%) > spent SiO₂ (?). The catalytic performance followed the same trend, suggesting that the surface-adsorbed oxygen species was the key factor for MPO process. Additionally, the carbon deposition rate increased in the order SiO₂ (16.8 mol/g_cat/s) > MCM-41 (11.7 mol/g_cat/s) > KCC-1 (7.7 mol/g_cat/s), consistent with the results of post-reaction Raman measurements. By coupling the in situ Fourier-transform infrared and XPS results, it is suggested that the high concentration of oxygen vacancies in KCC-1 contributed to activate the CH₄ molecules on acid sites via different O1-assisted kinetically relevant C–H bond activation mechanism for combustion-reforming pathway; meanwhile it provided an excellent adsorption-desorption cycle of O^2? species to inhibit the carbon deposition, thus creating a bifunctional reaction mechanism in MPO reaction.     

A Recyclable Heterogeneous Palladium Catalyst Anchored to Modified Metal-Organic Framework for Hydrogenation of Styrene Oxide

A heterogeneous palladium(II) catalyst anchored to modified metal-organic framework has been synthesized and characterized. The performance of the catalyst has been tested for the hydrogenation of styrene oxide at ambient temperature and pressure. The catalyst showed an excellent activity and selectivity for the preparation of 2-phenylethanol from styrene oxide with 100% conversion and 98% selectivity. The catalyst is very stable and easily recyclable for several times without loss of activity.

     

Click approach to the three‐component synthesis of novel β‐hydroxy‐1,2,3‐triazoles catalysed by new (Cu/Cu2O) nanostructure as a ligand‐free,green and regioselective nanocatalyst in water

Copper nanostructures were produced as an effective and regioselective catalyst for the synthesis of 1,2,3‐triazoles from a wide range of raw materials, such as sodium azide, epoxides and terminal alkynes, in water via a one‐pot three‐component click reaction. The new heterogeneous catalyst was prepared by a simple ball mill reduction of CuO with NaBH₄ using a ball‐to‐powder weight ratio of 50:1 under air atmosphere at room temperature. The catalyst was fully characterized using scanning electron microscopy, energy‐dispersive X‐ray analysis, Fourier transform infrared spectroscopy and X‐ray diffraction. The copper nanostructures catalysed both ring opening and triazole cyclization steps. Products were obtained in high yields and short reaction times. The reactions were performed at ambient temperature in water as a green solvent. The Cu/Cu₂O nanostructures revealed high reusability and high stability via a simple recycling process.     

Synthesis and Characterization of Novel Magnetic Poly(urethane-imide)/Fe3O4@SiO2–NH2 Nanocomposites

Russian Journal of Applied Chemistry - Poly(urethane-imide)/Fe3O4@SiO2–NH2 nanocomposites were synthesized by the reaction of 4,4′-diphenylmethane diisocyanate (MDI), polypropylene...