Antioxidative and Hepatoprotective Activities of Deinoxanthin-Rich Extract from Deinococcus radiodurans R1 against Carbon Tetrachloride-Induced Liver Injury in Mice

Purpose: To investigate the antioxidant activity and hepatoprotective effect of deinoxanthin-rich extract from Deinococcus radiodurans (EDR) against CCl4-induced liver injury in mice.Methods: The ethanol extract of EDR was analyzed by liquid  chromatography/mass spectrometry (LC/MS), and its antioxidant activity was examined using in vitro assays for reducing power, iron chelating activity and lipid peroxidation. The extract was also evaluated for its hepatoprotective activity against carbon tetrachloride-induced liver injury in mice. The activities of alanine aminotransferase (ALT), aspartate  aminotransferase (AST), alkaline phosphatase (ALP) in serum, and catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in liver tissue, as well as hepatic malondialdehyde (MDA) levels, were measured to monitor liver injury. Damage to liver cells was assessed by histology.Results: EDR displayed strong reducing activity and lipid peroxidation inhibition activity in vitro. Pretreatment with EDR (400 mg/kg b.w.)  significantly reduced activities of serum ALT, AST and ALP, as well as hepatic MDA levels (p < 0.05), but increased the activities of GSH-Px, CAT and SOD. Histopathological assessment showed that liver tissue damage was decreased by the protective effect of EDR.Conclusion: The results show that EDR can protect mice against  CCl4-induced hepatic damage by its antioxidant and free radical  scavenging activities.Keywords: Antioxidant, Deinoxanthin, Deinococcus radiodurans,   Hepatoprotective, Carbon tetrachloride, Liver damag

Global quark polarization in non-central A+AA+A collisions

Partons produced in the early stage of non-central heavy-ion collisions can develop a longitudinal fluid shear because of unequal local number densities of participant target and projectile nucleons. Under such fluid shear, local parton pairs with non-vanishing impact parameter have finite local relative orbital angular momentum along the direction opposite to the reaction plane. Such finite relative orbital angular momentum among locally interacting quark pairs can lead to global quark polarization along the same direction due to spin-orbital coupling. Local longitudinal fluid shear is estimated within both Landau fireball and Bjorken scaling model of initial parton production. Quark polarization through quark-quark scatterings with the exchange of a thermal gluon is calculated beyond small-angle scattering approximation in a quark-gluon plasma. The polarization is shown to have a non-monotonic dependence on the local relative orbital angular momentum dictated by the interplay between electric and magnetic interaction. It peaks at a value of relative orbital angular momentum which scales with the magnetic mass of the exchanged gluons. With the estimated small longitudinal fluid shear in semi-peripheral $Au+Au$ collisions at the RHIC energy, the final quark polarization is found to be small $|P_q|<0.04$ in the weak coupling limit. Possible behavior of the quark polarization in the strong coupling limit and implications on the experimental detection of such global quark polarization at RHIC and LHC are also discussed.Comment: 28 pages,11 figure

Novel five- and six-membered ring phosphorus-selenium heterocycles from selenation of amido-Schiff bases

Authors are grateful to the University of St Andrews for financial support.Woollins’ reagent, [2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide], serving as a selenating-reductive cycloaddition reagent, reacts with nonconjugated amido-Schiff bases to give the corresponding six-membered 1,3,4-selenadiazoles via a ring-expansion accompanied by an additional selenation/cyclization to the imine bond and C═O group; meanwhile, under the same reaction conditions, the selenation of conjugated amido-Schiff bases leads to a series of fused heterocycles with two five-membered rings. Eight single-crystal X-ray structures confirming the formation of these five- and six-membered heterocycles are discussed.Publisher PDFPeer reviewe

2-Phenyl-5-(p-tol­yl)-1,3,4-oxadiazole

The title compound, C15H12N2O, adopts the expected near-planar geometry, the phenyl and tolyl rings being inclined relative to the oxadiazole ring by 3.8 (3) and 8.3 (2)°, respectively. This allows adjacent mol­ecules to pack in a parallel fashion and form stacking along [010] via π–π inter­actions [centroid–centroid distances = 3.629 (2) and 3.723 (2) Å]. Further inter­molecular inter­actions include C—H⋯π inter­actions and weak C—H⋯N hydrogen bonds, giving rise to a crossed herringbone packing motif

Ising magnetism and ferroelectricity in Ca3_3CoMnO6_6

The origin of both the Ising chain magnetism and ferroelectricity in Ca$_3$CoMnO$_6$ is studied by $ab$ $initio$ electronic structure calculations and x-ray absorption spectroscopy. We find that Ca$_3$CoMnO$_6$ has the alternate trigonal prismatic Co$^{2+}$ and octahedral Mn$^{4+}$ sites in the spin chain. Both the Co$^{2+}$ and Mn$^{4+}$ are in the high spin state. In addition, the Co$^{2+}$ has a huge orbital moment of 1.7 $\mu_B$ which is responsible for the significant Ising magnetism. The centrosymmetric crystal structure known so far is calculated to be unstable with respect to exchange striction in the experimentally observed $\uparrow\uparrow\downarrow\downarrow$ antiferromagnetic structure for the Ising chain. The calculated inequivalence of the Co-Mn distances accounts for the ferroelectricity.Comment: 4 pages, 3 figures, PRL in press (changes made upon referees comments

Orbital order in La0.5Sr1.5MnO4: beyond a common local Jahn-Teller picture

The standard way to find the orbital occupation of Jahn-Teller (JT) ions is to use structural data, with the assumption of a one-to-one correspondence between the orbital occupation and the associated JT distortion, e.g. in O6 octahedron. We show, however, that this approach in principle does not work for layered systems. Specifically, using the layered manganite La0.5Sr1.5MnO4 as an example, we found from our x-ray absorption measurements and theoretical calculations, that the type of orbital ordering strongly contradicts the standard local distortion approach for the Mn3+O6 octahedra, and that the generally ignored long-range crystal field effect and anisotropic hopping integrals are actually crucial to determine the orbital occupation. Our findings may open a pathway to control of the orbital state in multilayer systems and thus of their physical properties.Comment: 4+ pages, 4 figure

Orbital occupation and magnetic moments of tetrahedrally coordinated iron in CaBaFe4O7

CaBaFe4O7 is a mixed-valent transition metal oxide having both Fe2+ and Fe3+ ions in tetrahedral coordination. Here we characterize its magnetic properties by magnetization measurements and investigate its local electronic structure using soft x-ray absorption spectroscopy at the Fe L2,3 edges, in combination with multiplet cluster and spin-resolved band structure calculations. We found that the Fe2+ ion in the unusual tetrahedral coordination is Jahn-Teller active with the high-spin e^2 (up) t2^3 (up) e^1 (down) configuration having a x^2-y^2-like electron for the minority spin. We deduce that there is an appreciable orbital moment of about L_z=0.36 caused by multiplet interactions, thereby explaining the observed magnetic anisotropy. CaBaFe4O7, a member of the '114' oxide family, offers new opportunities to explore charge, orbital and spin physics in transition metal oxides

Phosphorus-sulfur heterocycles incorporating an O-P(S)-O or O-P(S)-S-S-P(S)-O scaffold : one-pot synthesis and crystal structure study

The authors are grateful to the University of St Andrews for financial support.A new one-pot preparative route was developed to synthesize novel organophosphorus sulfur heterocycles via the reaction of the four-membered ring thionation reagent [2,4-diferrocenyl 1,3,2,4-diathiadiphosphetane 2,4-disulfide (FcLR, a ferrocene analogue of Lawesson’s reagent)] and alkenyl/aryl-diols and I2 (or SOCl2) in the presence of triethylamine. Therefore, a series of five- to ten-membered heterocycles bearing an O-P(S)-O or an O-P(S)-S-S-P(S)-O linkage were synthesized. The synthesis features a novel application of the multicomponent reaction, providing an efficient and environmentally benign method for the preparation of the unusual phosphorus-sulfur heterocycles. Seven representative X-ray structures confirm the formation of these heterocycles.Publisher PDFPeer reviewe