Advanced Nanoscale Surface Characterization of CuO Nanoflowers for Significant Enhancement of Catalytic Properties

In this work, advanced nanoscale surface characterization of CuO Nanoflowers synthesized by controlled hydrothermal approach for significant enhancement of catalytic properties has been investigated. The CuO nanoflower samples were characterized by field-emission scanning electron microscopy (FE-SEM), X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, high-resolution transmission electron microscopy (HR-TEM), selected-area electron diffraction (SAED), high-angular annular dark field scanning transmission electron microscopy (HAADF-STEM) with elemental mapping, energy dispersive spectroscopy (STEM-EDS) and UV–Vis spectroscopy techniques. The nanoscale analysis of the surface study of monodispersed individual CuO nanoflower confirmed the fine crystalline shaped morphology composed of ultrathin leaves, monoclinic structure and purified phase. The result of HR-TEM shows that the length of one ultrathin leaf of copper oxide nanoflower is about ~650–700 nm, base is about ~300.77 ± 30 nm and the average thickness of the tip of individual ultrathin leaf of copper oxide nanoflower is about ~10 ± 2 nm. Enhanced absorption of visible light ~850 nm and larger value of band gap energy (1.68 eV) have further supported that the as-grown material (CuO nanoflowers) is an active and well-designed surface morphology at the nanoscale level. Furthermore, significant enhancement of catalytic properties of copper oxide nanoflowers in the presence of H2O2 for the degradation of methylene blue (MB) with efficiency ~96.7% after 170 min was obtained. The results showed that the superb catalytic performance of well-fabricated CuO nanoflowers can open a new way for substantial applications of dye removal from wastewater and environment fields.     

Possible Participation of Ionotropic Glutamate Receptors and l-Arginine-Nitric Oxide-Cyclic Guanosine Monophosphate-ATP-Sensitive K+ Channel Pathway in the Antinociceptive Activity of Cardamonin in Acute Pain Animal Models

The perception of pain caused by inflammation serves as a warning sign to avoid further injury. The generation and transmission of pain impulses involves various pathways and receptors. Cardamonin isolated from Boesenbergia rotunda (L.) Mansf. has been reported to exert antinociceptive effects in thermal and mechanical pain models; however, the precise mechanism has yet to be examined. The present study investigated the possible mechanisms involved in the antinociceptive activity of cardamonin on protein kinase C, N-methyl-d-aspartate (NMDA) and non-NMDA glutamate receptors, l-arginine/cyclic guanosine monophosphate (cGMP) mechanism, as well as the ATP-sensitive potassium (K⁺) channel. Cardamonin was administered to the animals intra-peritoneally. Present findings showed that cardamonin significantly inhibited pain elicited by intraplantar injection of phorbol 12-myristate 13-acetate (PMA, a protein kinase C activator) with calculated mean ED₅₀ of 2.0 mg/kg (0.9–4.5 mg/kg). The study presented that pre-treatment with MK-801 (NMDA receptor antagonist) and NBQX (non-NMDA receptor antagonist) significantly modulates the antinociceptive activity of cardamonin at 3 mg/kg when tested with glutamate-induced paw licking test. Pre-treatment with l-arginine (a nitric oxide precursor), ODQ (selective inhibitor of soluble guanylyl cyclase) and glibenclamide (ATP-sensitive K⁺ channel inhibitor) significantly enhanced the antinociception produced by cardamonin. In conclusion, the present findings showed that the antinociceptive activity of cardamonin might involve the modulation of PKC activity, NMDA and non-NMDA glutamate receptors, l-arginine/nitric oxide/cGMP pathway and ATP-sensitive K⁺ channel.     

Activation cross-sections for209Bi(n,α)206Tl reaction

Cross-section for²⁰⁹Bi(n, α)²⁰⁶Tl reaction at incident neutron energies 340±150 keV and 575±235 keV have been measured to be 1.26±0.18 μb and 1.55±0.23 μb, respectively. The activation technique was used for measuring the cross-sections. These values have been compared with theoretical values based on Hauser Feshbach Statistical Model.     

New heterotrinuclear complexes containing copper(II) and a group IV metal

Summary Heterotrinuclear complexes of the type [Cu₂(TETA)₂Cl₄M] (M = Si, Ge, Sn, Ti and Zr; TETA = triethylene tetramine) have been prepared by direct reaction of [Cu[TETA)]Cl₂ with MCl₄ in a 21 ratio in MeOH. The compounds have been characterized by elemental analyses, e.s.r., electronic and i.r. spectra, magnetic susceptibility and conductivity measurements. The results indicate that [Cu(TETA)]Cl₂ is square planar and ionic, while its heterotrinuclear complexes, [Cu₂(TETA)₂Cl₄M], are covalent with an octahedral environment around the copper(II) ion.     

The effect of complexing agents on the DMF–chromium(VI) reaction. A kinetic study

The kinetics of the reduction of chromium(VI) by dimethylformamide (DMF) in the presence of ethylenediaminetetraacetic acid (EDTA) and 2,2-bipyridyl (bpy) was investigated in aqueous HClO₄ acid solutions spectrophotometrically. The experimental findings, that the reaction has an induction period followed by autoacceleration, is explained. After the reduction, chromium(III) is present as the EDTA- and bpy-complexes, although such complexes form very slowly under the same experimental conditions from chromium(III) and the EDTA and bpy, respectively. Increases in the reaction rate with increasing [EDTA] were observed, while added bpy had negligible effect on the reaction rate. The reaction is first-order each in [Cr^VI] and [H⁺]. The first-order kinetics with respect to EDTA at low concentrations shift to zero-order at higher concentrations. The reaction is considered to proceed through the formation of a very stable chromium(VI)–DMF–EDTA complex. The suggested mechanism refers only to the induction period of the reaction. The net rate of oxidation of DMF, as measured by the consumption of chromium (VI), is given by: –d[Cr^VI]/dt = kK ₁ K _b[H⁺][DMF]_T[EDTA][Cr^VI]_T/(1 + K ₁[EDTA])(1 + K _b[H⁺])     

Oxidation of lactic acid by water soluble (colloidal) manganese dioxide

Spectrophotometric method has been used to characterize water‐soluble colloidal manganese dioxide obtained by the redox reaction between sodium thiosulphate and potassium permanganate in neutral aqueous medium which shows a single peak in the visible region with λ_max = 425 nm. The kinetics of the oxidation of lactic acid by colloidal manganese dioxide (oxidant) has been investigated spectrophotometrically under pseudo‐first‐order conditions of excess lactic acid. The rate of the noncatalytic reaction pathway was slow which increased with increasing lactic acid concentration. The reaction was first‐order with respect to [oxidant] as well as [lactic acid]. In presence of manganase(II) and fluoride ions, the noncatalytic path disappeared completely while the oxidation rate of autocatalytic path increased and decreased, respectively with increasing [Mn(II)] and [F^?]. A mechanistic scheme in conformity with the observed kinetics has been proposed with the rate‐law: © 2004 Wiley Periodicals, Inc. Int J Chem Kinet 36: 359–366 2004     

Effect of dicationic gemini surfactants 16–s‐16 (s = 4, 5, 6) on the ninhydrin‐dipeptide (glycyl‐tyrosine) reaction

The effect of dicationic gemini surfactants H₃₃C₁₆(CH₃)₂N⁺‐(CH₂)_s‐N⁺(CH₃)₂ C₁₆H₃₃, 2Br^? (s= 4, 5, 6) on the reaction of a dipeptide glycyl–tyrosine (Gly–Tyr) with ninhydrin has been studied spectrophotometrically at 70°C and pH 5.0. The reaction follows first‐ and fractional‐order kinetics, respectively, in [Gly–Tyr] and [ninhydrin]. The gemini surfactant micellar media are comparatively more effective than their single chain–single head counterpart cetyltrimethylammonium bromide (CTAB) micelles. Whereas typical rate constant (k_Ψ) increase and leveling‐off regions, just like CTAB, are observed with geminis, the latter produces a third region of increasing k_Ψ at higher concentrations. This subsequent increase is ascribed to the change in the micellar morphology of the geminis. The pseudophase model of micelles was used to quantitatively analyze the k_Ψ ? [gemini] data, wherein the micellar‐binding constants K_S for [Gly–Tyr] and K_N for ninhydrin were evaluated. © 2012 Wiley Periodicals, Inc. Int J Chem Kinet 44: 800–809, 2012     

The Role of Allium subhirsutum L. in the Attenuation of Dermal Wounds by Modulating Oxidative Stress and Inflammation in Wistar Albino Rats

In our study, Allium subhirsutum L. (AS) was investigated to assess its phenolic profile and bioactive molecules including flavonoids and organosulfur compounds. The antioxidant potential of AS and wound healing activity were addressed using skin wound healing and oxidative stress and inflammation marker estimation in rat models. Phytochemical and antiradical activities of AS extract (ASE) and oil (ASO) were studied. The rats were randomly assigned to four groups: group I served as a control and was treated with simple ointment base, group II was treated with ASE ointment, group III was treated with ASO ointment and group IV (reference group; Ref) was treated with a reference drug “Cytolcentella^® cream”. Phytochemical screening showed that total phenols (215 ± 3.5 mg GAE/g) and flavonoids (172.4 ± 3.1 mg QE/g) were higher in the ASO than the ASE group. The results of the antioxidant properties showed that ASO exhibited the highest DPPH free radical scavenging potential (IC50 = 0.136 ± 0.07 mg/mL), FRAP test (IC50 = 0.013 ± 0.006 mg/mL), ABTS test (IC50 = 0.52 ± 0.03 mg/mL) and total antioxidant capacity (IC50 = 0.34 ± 0.06 mg/mL). In the wound healing study, topical application of ASO performed the fastest wound-repairing process estimated by a chromatic study, percentage wound closure, fibrinogen level and oxidative damage status, as compared to ASE, the Cytolcentella reference drug and the untreated rats. The use of AS extract and oil were also associated with the attenuation of oxidative stress damage in the wound-healing treated rats. Overall, the results provided that AS, particularly ASO, has a potential medicinal value to act as effective skin wound healing agent.