ABSTRACT
A novel anion-deficient perovskite-based compound, Pb(2.4)Ba(2.6)Fe(2)Sc(2)TiO(13), was synthesized via the citrate-based route. This compound is an n = 5 member of the AnBnO(3n-2) homologous series with unit-cell parameters related to the perovskite subcell a(p)≈ 4.0 Å as a(p)â2 ×a(p)× 5a(p)â2. The crystal structure of Pb(2.4)Ba(2.6)Fe(2)Sc(2)TiO(13) consists of quasi-2D perovskite blocks with a thickness of three octahedral layers separated by the 1/2[110](1[combining macron]01)(p) crystallographic shear (CS) planes, which are parallel to the {110} plane of the perovskite subcell. The CS planes transform the corner-sharing octahedra into chains of edge-sharing distorted tetragonal pyramids. Using a combination of neutron powder diffraction, (57)Fe Mössbauer spectroscopy and atomic resolution electron energy-loss spectroscopy we demonstrate that the B-cations in Pb(2.4)Ba(2.6)Fe(2)Sc(2)TiO(13) are ordered along the {110} perovskite layers with Fe(3+) in distorted tetragonal pyramids along the CS planes, Ti(4+) preferentially in the central octahedra of the perovskite blocks and Sc(3+) in the outer octahedra of the perovskite blocks. Magnetic susceptibility and Mössbauer spectroscopy indicate a broadened magnetic transition around T(N)â¼ 45 K and the onset of local magnetic fields at low temperatures. The magnetic order is probably reminiscent of that in other AnBnO(3n-2) homologues, where G-type AFM order within the perovskite blocks has been observed.
ABSTRACT
ZnO-Co nanocomposite thin films are synthesized by combination of pulsed laser deposition of ZnO and Co ion implantation. Both superparamagnetism and relaxor ferroelectricity as well as magnetoelectric coupling in the nanocomposites have been demonstrated. The unexpected relaxor ferroelectricity is believed to be the result of the local lattice distortion induced by the incorporation of the Co nanoparticles. Magnetoelectric coupling can be attributed to the interaction between the electric dipole moments and the magnetic moments, which are both induced by the incorporation of Co. The introduced ZnO-Co nanocomposite thin films are different from conventional strain-mediated multiferroic composites.
ABSTRACT
Significant reduction in hemorrhage (10 v/s 13), necrosis (2 v/s 4), cavitations (7 v/s 13), neuronal degeneration, perivascular and parenchymal inflammatory infiltrate (7 v/s 11) were observed in Vitamin E treated cold induced head injury in guinea pigs, evaluated post injury using the modified Benderson's scale. The results suggest that Vitamin E is highly effective in promoting clinical and histopathological recovery in cold induced head injury in guinea pigs.
Subject(s)
Antioxidants/therapeutic use , Brain Injuries/drug therapy , Cold Temperature , Neuroprotective Agents/therapeutic use , Vitamin E/therapeutic use , Animals , Brain/pathology , Brain Injuries/pathology , Female , Guinea Pigs , Male , Random AllocationSubject(s)
Hematoma, Epidural, Cranial/diagnosis , Hematoma, Epidural, Cranial/etiology , Hematoma/diagnostic imaging , Hematoma/etiology , Orbit/injuries , Orbital Diseases/diagnosis , Orbital Diseases/etiology , Adolescent , Craniotomy , Diagnosis, Differential , Hematoma/surgery , Hematoma, Epidural, Cranial/surgery , Humans , Male , Orbital Diseases/surgery , Periosteum , RadiographyABSTRACT
Traumatic brain injury following birth is common in newborn but significant intracranial haematoma following birth injury is not that usual. Even busy pediatric trauma center have about only 1 to 3 % of admission that require neurosurgical care. Extradural haematoma (EDH) associated with intracerebral and subdural haematoma (SDH) is even more rare in newborn. If this is not detected and treated in time, the outcome may be fatal. A case of EDH with subdural and intracerebral haematoma in a 3 days old neonate is presented. Etiology and problems in diagnosis and management are discussed.