Antioxidant activity of some edible plants of the Turkmen Sahra region in northern Iran

The antioxidant properties of 10 edible plants of the Turkmen Sahra region in Golestan province in northern Iran, including Allium paradoxum, Allium rubellum, Foeniculum vulgare, Mentha longifolia, Origanum vulgare, Prunus divaricata, Rubus sanctus, Rumex tuberosus, Satureja mutica and Spinacia turkestanica were evaluated by four different methods; free radical scavenging using 2,2-diphenyl-1-picrylhydrazyl (DPPH), evaluation of xanthine-oxidase activity, inhibition of lipid peroxidation by the ferric thiocyanate method, and the deoxyribose degradation assay. All species tested except A. paradoxum and P. divaricata showed antioxidant activity at least in one assay.     

Facile synthesis of Co3O4 nanoparticles from a novel tetranuclear cobalt(III) complex. Application as efficient electrocatalyst for oxygen evolution reaction in alkaline media

A tetranuclear cobalt complex [Co₄^III(L′)₆] was synthesized by the direct reaction of cobalt(II) acetate with a N₂S₂ Schiff base ligand H₂L containing a disulfide bond under aerobic conditions {H₂L = 2,2′-bis(2-hydroxynaphthyliminobenzyl)disulfide}. The X-ray crystal structure of [Co₄^III(L′)₆] indicates reductive disulfide bond scission of H₂L upon reaction with Co²⁺ to give [L^′]^2–. Furthermore, cobalt oxide nanoparticles of about 30 nm size were synthesized by thermal decomposition of [Co₄^III(L′)₆] as a precursor. The Co₃O₄ nanoparticles were characterized by XRD, FE-SEM, TEM, and FT-IR spectroscopy. The electrocatalytic activity of the resulting oxide was examined in oxygen evolution reaction (OER) by cyclic voltammetry (CV) and linear sweep voltammetry (LSV) in 1.0 mol L^?1 KOH. The NPs displays efficient electrocatalytic activity for oxygen evolution reaction with a current density of 10.0 mA cm^?2 at 1.65 V, good onset potential of 1.52 V vs. RHE and small Tafel slope of 44 mV dec^?1.     

Mixed logit analysis of bicyclist injury severity resulting from motor vehicle crashes at intersection and non-intersection locations

Standard multinomial logit (MNL) and mixed logit (MXL) models are developed to estimate the degree of influence that bicyclist, driver, motor vehicle, geometric, environmental, and crash type characteristics have on bicyclist injury severity, classified as property damage only, possible, nonincapacitating or severe (i.e., incapacitating or fatal) injury. This study is based on 10,029 bicycleinvolved crashes that occurred in the State of Ohio from 2002 to 2008. Results of likelihood ratio tests reveal that some of the factors affecting bicyclist injury severity at intersection and non-intersection locations are substantively different and using a common model to jointly estimate impacts on severity at both types of locations may result in biased or inconsistent estimates. Consequently, separate models are developed to independently assess the impacts of various factors on the degree of bicyclist injury severity resulting from crashes at intersection and non-intersection locations.Several covariates are found to have similar impacts on injury severity at both intersection and non-intersection locations. Conversely, six variables were found to significantly influence injury severity at intersection locations but not non-intersection locations while four variables influenced bicyclist injury severity only at non-intersection locations. In crashes occurring at intersection locations, the likelihood of severe bicyclist injury increases by 14.8 percent if the bicyclist is not wearing a helmet, 82.2 percent if the motorist is under the influence of alcohol, 141.3 percent if the crash-involved motor vehicle is a van, 40.6 percent if the motor vehicle strikes the side of the bicycle, and 182.6 percent if the crash occurs on a horizontal curve with a grade. Results from non-intersection locations show the likelihood of severe injuries increases by 374.5 percent if the bicyclist is under the influence of drugs, 150.1 percent if the motorist is under the influence of alcohol, 53.5 percent if the motor vehicle strikes the side of the bicycle and 99.9 percent if the crash-involved motor vehicle is a heavy-duty truck.     

Fano-Like Resonance from Disorder Correlation in Vacancy-Doped Photonic Crystals

By preparing colloidal crystals with random missing scatterers, crystals are created where disorder is embodied as vacancies in an otherwise perfect lattice. In this special system, there is a critical defect concentration where light propagation undergoes a transition from an all but perfect reflector (for the spectral range defined by the Bragg condition), to a metamaterial exhibiting an enhanced transmission phenomenon. It is shown that this behavior can be phenomenologically described in terms of Fano-like resonances. The results show that the Fano's parameter q experiences a sign change signaling the transition from a perfect crystal exhibiting a reflectance Bragg peak, through a state where background scattering is maximum and Bragg reflectance reaches a minimum to a point where the system reenters a low scattering state recovering ordinary Bragg diffraction. A simple dipolar model considering the correlation between scatterers and vacancies is proposed and the reported evolution of the Fano-like scattering is explained in terms of the emerging covariance between the optical paths and polarizabilities and the effect of field enhancement in photonic crystal (PhC) defects.     

MOF-Based Solid-State Proton Conductors Obtained by Intertwining Protic Ionic Liquid Polymers with MIL-101

Solid-state proton conductors based on the use of metal–organic framework (MOF) materials as proton exchange membranes are being investigated as alternatives to the current state of the art. This study reports a new family of proton conductors based on MIL-101 and protic ionic liquid polymers (PILPs) containing different anions. By first installing protic ionic liquid (PIL) monomers inside the hierarchical pores of a highly stable MOF, MIL-101, then carrying out polymerization in situ, a series of PILP@MIL-101 composites was synthesized. The resulting PILP@MIL-101 composites not only maintain the nanoporous cavities and water stability of MIL-101, but the intertwined PILPs provide a number of opportunities for much-improved proton transport compared to MIL-101. The PILP@MIL-101 composite with HSO₄⁻ anions shows superprotonic conductivity (6.3 × 10⁻² S cm⁻¹) at 85 °C and 98% relative humidity. The mechanism of proton conduction is proposed. In addition, the structures of the PIL monomers were determined by single crystal X-ray analysis, which reveals many strong hydrogen bonding interactions with O/N H···O distances below 2.6 Å.