Synthesis, characterization, and sensitivity tests of La0.8Ba0.1Bi0.1FeO3 nanoparticles towards a few parts-per-billion of acetone gas.

In the present paper, the La0.8Ba0.1Bi0.1FeO3 powders were synthesized via the auto-combustion method. The optical, the positron annihilation spectroscopy and the gas sensing properties of our sample were investigated simultaneously. FTIR spectrum revealed the antisymmetric deformation vibrations of the Fe-O and Fe-O-Fe bonds inside the octahedron FeO6. The optical bandgap (Egap) of the La0.8Ba0.1Bi0.1FeO3 compound was found to be equal to 2.23 eV. We confirmed by the positron annihilation studies, the existence of open volume defects and vacancy sized defects, at the grain/interfaces between vacancy clusters and grains at the interfaces intersection (triple-lines). Notably, the La0.8Ba0.1Bi0.1FeO3 perovskite exhibits an excellent response toward acetone gas, with ultra-fast response and recovery times to some parts-per-billion (ppb) of this tested gas.

Single large-scale mitochondrial DNA deletion in a patient with mitochondrial myopathy associated with multiple symmetric lipomatosis.

In a nonalcoholic woman with multiple symmetric lipomatosis (MSL), muscle histochemistry showed ragged-red fibers and cytochrome c oxidase negative fibers. Southern blot analysis revealed a single deletion of mitochondrial DNA (mtDNA). We suggest that MSL is an uncommon manifestation of the wide clinical spectrum of mitochondrial disorders, in particular of those associated with single mtDNA deletions.

[Study of primary resistance to antitubercular drugs in Galicia]. / Estudio de las resistencias primarias a fármacos antituberculosos en Galicia.

The primary resistance of 100 specimens of Mycobacterium tuberculosis isolated in patients with active tuberculosis confirmed bacteriologically was studied prospectively over a period of 15 months. Strains resistant to 1 or more drugs were found in 5 patients. Three patients presented resistance to 2 drugs (isoniazide and streptomycin in 2 and rifampicin and isoniazid, streptomycin and ethambutol); and the fifth was resistant only to pyrazinamide. Owing to the few instances of primary resistance found, it was impossible to establish whether any of the factors analyzed in each patient was related to a higher index of resistance, although 4 of the 5 resistant strains came from respiratory specimens. We conclude that the index of primary resistance in our area is low and this allows us to do without prescribing a fourth drug in the first two months of anti-tuberculosis therapy, and makes routine sensitivity tests unnecessary for patients with no history of prior treatment for tuberculosis.