20 research outputs found
Phenotypic and genotypic evaluation of slime production by conventional and molecular microbiological techniques
Twenty-nine staphylococcal isolates from different clinical samples were tested for
slime production: phenotypic characterization was carried out using Christensen test
(tube test) and Congo red agar plate test (CRA plate test), while the presence and
expression of icaA and icaD genes were evaluated by real-time PCR. In 79.3% of
studied strains there was a concordance between slime production and presence
of icaA and icaD genes, and between lack of slime production and absence of both or
only one of the tested genes. In four of five strains where positive phenotype was not
associated with the presence of ica genes, gene co-expression (evaluated by mRNA
determination) was lacking, while in only a case out of five, there was the presence
of transcripts without phenotype. Our study, for the first time, introduces real-time
PCR for the detection of both icaA and icaD genes and their mRNA and, furthermore,
addresses the relationship between slime phenotype absence and mRNA expression,
in clinical isolates of coagulase-negative staphylococci
Effect of low-dosage recombinant human growth hormone therapy on pulmonary function in hypopituitary patients with adult-onset growth hormone deficiency
Insulin-Like Growth Factor-I in Human Malnutrition: Relationship with Some Body Composition and Nutritional Parameters
VOC emissions influence intra- and interspecific interactions among stored-product Coleoptera in paddy rice
QBC® for the diagnosis of human and canine american visceral leishmaniasis: preliminary data
Hydrogen peroxide route to Sn-doped titania photocatalysts
<p>Abstract</p> <p>Background</p> <p>The work aims at improving photocatalytic activity of titania under Vis light irradiation using modification by Sn ions and an original, simple synthesis method. Tin-doped titania catalysts were prepared by thermal hydrolysis of aqueous solutions of titanium peroxo-complexes in the presence of SnCl<sub>4</sub> or SnCl<sub>2</sub> using an original, proprietary "one pot" synthesis not employing organic solvents, metallo-organic precursors, autoclave aging nor post-synthesis calcination. The products were characterized in details by powder diffraction, XPS, UV–vis, IR, and Raman spectroscopies, electron microscopy and surface area and porosity measurements</p> <p>Results</p> <p>The presence of tin in synthesis mixtures favors the formation of rutile and brookite at the expense of anatase, decreases the particle size of all formed titania polymorphs, and extends light absorption of titania to visible light region >400 nm by both red shift of the absorption edge and introduction of new chromophores. The photocatalytic activity of titania under UV irradiation and >400 nm light was tested by decomposition kinetics of Orange II dye in aqueous solution</p> <p>Conclusions</p> <p>Doping by Sn improves titania photoactivity under UV light and affords considerable photoactivity under >400 nm light due to increased specific surface area and a phase heterogeneity of the Sn-doped titania powders.</p