A rare case of medulloblastoma coexisting with multiple spinal intramedullary tumors.

Medulloblastoma is the most common primary central nervous system tumor of childhood. Medulloblastoma can metastasize along the neuraxis and to extraneural locations, but multiple intramedullary spinal metastases are very rare. The usual presenting clinical features are related to posterior fossa syndrome and/or hydrocephalus. We describe a unique case of medulloblastoma with multiple intramedullary lesions at the D-7 and D-12 levels.

Surgical management of pygopagus conjoined twins with spinal bifida.

PURPOSE: Conjoined twins are a rare complication of 9 monozygotic twins and are associated with high perinatal mortality. Pygopagus are one of the rare types of conjoined twins with only a handful of cases reported in the literature. We present the case of one-and-half month-old male pygopagus conjoined twins, who were joined together dorsally in lower lumbar and sacral region and had spina bifida and shared a single thecal sac with combined weight of 6.14 kg. Spinal cord was separated at the level of the conus followed by duraplasty. They had uneventful recovery with normal 15 months follow-up. CONCLUSION: Separation of conjoined twins is recommended in where this is feasible with the anticipated survival of both or one infant.

Copper-iron-molybdenum mixed oxides as efficient oxygen evolution electrocatalysts.

Ternary Cu, Fe and Mo mixed oxides having a nominal compositional formula, CuxFe2-x(MoO4)3 (0 ≤ x ≤ 1.5), have been prepared by a co-precipitation method at pH ≈ 2 and characterized by FT-IR, XRD, XPS, TEM and anodic polarization techniques for use as electrocatalysts for the oxygen evolution reaction (OER) in alkaline solutions. The crystallites of oxides with x ≤ 1 have the monoclinic crystal structure. The OER study shows that replacement of Fe in the Fe2(MoO4)3 matrix by 0.25-1.0 mol Cu increases the apparent electrocatalytic activity. However, 1.5 mol Cu-addition is detrimental to the OER activity. At E = 1.51 V (vs. RHE) in 1 M KOH, the catalytic activity of the oxide with x = 1 was approximately 50 times the activity of the base oxide (i.e. Fe2(MoO4)3). The Tafel slope of oxides with 0.25 ≤ x ≤ 1.5 ranged between 31 and 37 mV. The reaction order of OH(-) concentration was nearly unity for oxides with x = 0.25 and 1.5 and it was ∼2 for oxides with x = 0.5, 0.75, and 1.0. Suitable reaction mechanisms consistent with the electrode kinetic parameters have also been proposed.

Graphene-cobaltite-Pd hybrid materials for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells.

Hybrid materials comprising of Pd, MCo2O4 (where M = Mn, Co or Ni) and graphene have been prepared for use as efficient bifunctional electrocatalysts in alkaline direct methanol fuel cells. Structural and electrochemical characterizations were carried out using X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, chronoamperometry and cyclic, CO stripping, and linear sweep voltammetries. The study revealed that all the three hybrid materials are active for both methanol oxidation (MOR) and oxygen reduction (ORR) reactions in 1 M KOH. However, the Pd-MnCo2O4/GNS hybrid electrode exhibited the greatest MOR and ORR activities. This active hybrid electrode has also outstanding stability under both MOR and ORR conditions, while Pt- and other Pd-based catalysts undergo degradation under similar experimental conditions. The Pd-MnCo2O4/GNS hybrid catalyst exhibited superior ORR activity and stability compared to even Pt in alkaline solutions.