4,302 research outputs found
Possible origin of -relaxation in amorphous metal alloys from atomic-mass differences of the constituents
We employ an atomic-scale theory within the framework of nonaffine lattice
dynamics to uncover the origin of the Johari-Goldstein (JG) -relaxation
in metallic glasses (MGs). Combining simulation and experimental data with our
theoretical approach, we reveal that the large mass asymmetry between the
elements in a LaNiAl MG leads to a clear separation in the
respective relaxation time scales, giving strong evidence that JG relaxation is
controlled by the lightest atomic species present. Moreover, we show that only
qualitative features of the vibrational density of states determine the overall
observed mechanical response of the glass, paving the way for a possible
unified theory of secondary relaxations in glasses
Poly[bis[μ-1,3-bis(diphenylphosphanyl)propane-κ2 P:P′]-di-μ-thiocyanato-κ2 S:N;κ2 N:S-disilver(I)]
In the title coordination polymer, [Ag2(NCS)2(C27H26P2)2]n, two centrosymmetrically related Ag+ cations are linked by two thiocyanate anions into binuclear eight-membered macrocycles. The Ag⋯Ag separation within the macrocycle is 5.4400 (6) Å. The distorted tetrahedral coordination about each metal atom is completed by the P atoms of two bridging 1,3-bis(diphenylphosphanyl)propane ligands, forming polymeric ribbons parallel to the a axis
PGC-1 α
Aim. To investigate the effect of Tongxinluo (Txl), a Chinese herbal compound, on diabetic peripheral neuropathy (DPN). Methods and Results. Diabetic rat model was established by peritoneal injection of streptozotocin (STZ). Txl ultrafine powder treatment for 16 weeks from the baseline significantly reversed the impairment of motor nerve conductive velocity (MNCV), mechanical hyperalgesia, and nerve structure. We further proved that Tongxinluo upregulates PGC-1α and its downstream factors including COX IV and SOD, which were involved in mitochondrial biogenesis. Conclusion. Our study indicates that the protective effect of Txl in diabetic neuropathy may be attributed to the induction of PGC-1α and its downstream targets. This finding may further illustrate the pleiotropic effect of the medicine
μ-4,4′-Bipyridine-bis[aqua(4-hydroxypyridine-2,6-dicarboxylato)copper(II)]
The title compound, [Cu2(C7H3NO5)2(C10H8N2)(H2O)2], exhibits a centrosymmetric binuclear molecule. Each completely deprotonated 4-hydroxypyridine-2,6-dicarboxylic acid molecule assumes a tridentate chelating coordination mode. The square-pyramidal coordination geometry around the CuII ion is completed by the bridging bipyridine ligand and an apical water molecule. Adjacent complexes are connected via O—H⋯O and C—H⋯O hydrogen bonds to generate a three-dimensional supramolecular structure
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