111 research outputs found
Visible light photoactivity of Polypropylene coated Nano-TiO2 for dyes degradation in water
The use of Polypropylene as support material for nano-TiO2 photocatalyst in the photodegradation of Alizarin Red S in water solutions under the action of visible light was investigated. The optimization of TiO2 pastes preparation using two commercial TiO2, Aeroxide P-25 and Anatase, was performed and a green low-cost dip-coating procedure was developed. Scanning electron microscopy, Atomic Force Microscopy and X-Ray Diffraction analysis were used in order to obtain morphological and structural information of as-prepared TiO2 on support material. Equilibrium and kinetics aspects in the adsorption and successive photodegradation of Alizarin Red S, as reference dye, are described using polypropylene-TiO2 films in the Visible/TiO2/water reactor showing efficient dyes degradation
Comprehensive genetic assessment of a functional TLR9 promoter polymorphism: no replicable association with asthma or asthma-related phenotypes
<p>Abstract</p> <p>Background</p> <p>Prior studies suggest a role for a variant (rs5743836) in the promoter of toll-like receptor 9 (TLR9) in asthma and other inflammatory diseases. We performed detailed genetic association studies of the functional variant rs5743836 with asthma susceptibility and asthma-related phenotypes in three independent cohorts.</p> <p>Methods</p> <p>rs5743836 was genotyped in two family-based cohorts of children with asthma and a case-control study of adult asthmatics. Association analyses were performed using chi square, family-based and population-based testing. A luciferase assay was performed to investigate whether rs5743836 genotype influences TLR9 promoter activity.</p> <p>Results</p> <p>Contrary to prior reports, rs5743836 was not associated with asthma in any of the three cohorts. Marginally significant associations were found with FEV<sub>1 </sub>and FVC (p = 0.003 and p = 0.008, respectively) in one of the family-based cohorts, but these associations were not significant after correcting for multiple comparisons. Higher promoter activity of the CC genotype was demonstrated by luciferase assay, confirming the functional importance of this variant.</p> <p>Conclusion</p> <p>Although rs5743836 confers regulatory effects on TLR9 transcription, this variant does not appear to be an important asthma-susceptibility locus.</p
The rs5743836 polymorphism in TLR9 confers a population-based increased risk of non-Hodgkin lymphoma
We are grateful to Paulo Vieira, CecĂlia LeĂŁo, Manuel T. Silva, Nuno Sousa, Jorge Correia-
Pinto, Joana Palha, Margarida Correia-Neves, Margarida Lima and Matthew Berry for all their
input throughout these studies and critical reading of the manuscript. We are grateful to the patients who joint this study as well as to all members of the Life and Health Sciences Research Institute and School of Health Sciences, University of Minho, who contributed in any way to the development of this workNon-Hodgkin lymphoma (NHL) has been associated with immunological defects, chronic inflammatory and autoimmune conditions. Given the link between immune dysfunction and NHL, genetic variants in toll-like receptors (TLRs) have been regarded as potential predictive factors of susceptibility to NHL. Adequate anti-tumoral responses are known to depend on TLR9 function, such that the use of its synthetic ligand is being targeted as a therapeutic strategy. We investigated the association between the functional rs5743836 polymorphism in the TLR9 promoter and risk for B-cell NHL and its major subtypes in three independent case-control association studies from Portugal (1160 controls, 797 patients), Italy (468 controls, 494 patients) and the US (972 controls, 868 patients). We found that the rs5743836 polymorphism was significantly overtransmitted in both Portuguese (odds ratio (OR), 1.85; P=7.3E-9) and Italian (OR, 1.84; P=6.0E-5) and not in the US cohort of NHL patients. Moreover, the increased transcriptional activity of TLR9 in mononuclear cells from patients harboring rs5743836 further supports a functional effect of this polymorphism on NHL susceptibility in a population-dependent manner.AC, NSO, MTC, and AJA were financially supported by a fellowship from Fundação para a CiĂȘncia e Tecnologia, Portugal. MS is a CiĂȘncia 2007 fellow. This study was supported by Fundação para a CiĂȘncia e Tecnologia, Portugal (PIC/IC/83313/2007) and by Fundação Calouste Gulbenkian, Serviço de SaĂșde e Desenvolvimento Humano, Portugal (Grant Number:Proc/60666-MM/734). CFS, PB and LC were supported by National Institutes of Health (NIH) grants CA122663 and CA104682, and PB also by NIH grants CA45614 and CA89745
Numerical investigation of transient thermal behavior of a wall incorporating a phase change material via a hybrid scheme
International audienc
Photochemical oxidation of styrene in acetonitrile solution in presence of H2O2, TiO2/H2O2 and ZnO/H2O2
International audienc
Thermal behavior of a hybrid PCM/plaster: A numerical and experimental investigation
International audienc
Electron transfer in ZnO-Fe2O3aqueous slurry systems and its effects on visible light photocatalytic activity
ZnFex(x = 0.025, 0.05, and 0.1) nanocomposites and pure ZnO and Fe2O3photocatalysts were synthesized by a simple sol-gel route and characterized by means of specific surface area (SSA) analysis, X-ray diffraction (XRD), diffuse reflectance spectroscopy (DRS), and transmission electron microscopy/energy dispersive X-ray spectroscopy (TEM/EDS). Their photocatalytic activity was investigated under visible light by using methylene blue (MB) and benzoic acid (BA) as model compounds. Coupling ZnO and Fe2O3results in higher photocatalytic activity with respect to the pure materials. Photoelectrochemical characterization performed in slurry systems allowed the elucidation of the electronic structure of the nanocomposites under conditions strongly mimicking the photocatalytic reaction medium. Intense electronic interactions between ZnO and Fe2O3induce a shift of the bandgap absorption to longer wavelengths. Furthermore a shift of the photogenerated electron potential towards less negative values could be evidenced for the first time by means of these measurements. The electronic configuration obtained after coupling the two semiconductors reduces recombination through efficient electron transfer from Fe2O3to ZnO, thus justifying the observed photoactivity results
Fate of nitrogen atoms in the photocatalytic degradation of industrial (congo red) and alimentary (amaranth) azo dyes. Evidence for mineralization into gaseous dinitrogen
The photocatalytic degradation of two azo-dyesâan industrial one (Congo Red (CR)), and an
alimentary one (Amaranth (AM))âhas been investigated in TiO2/UV aqueous suspensions. In addition to a
prompt removal of the colors, TiO2/UV-based photocatalysis was simultaneously able to fully oxidize the
dyes, with a complete mineralization of organic carbon into CO2. In particular, the aromatic rings were submitted
to successive attacks by photogenerated OHâ radicals leading to hydroxylated metabolites before the
ring opening and the final evolution of CO2 induced by repeated subsequent âphoto-Kolbeâ reactions with
carboxylic intermediates. Simultaneously, sulfur heteroatoms were converted into innocuous SO42â ions. The mineralization of nitrogen was more complex to analyze. Nitrogen atoms in the -3 oxidation state, such
as in the amino-groups of CR, initially remained at this reduction degree and produced NH4+ cations, subsequently and very slowly converted into NO3â anions. For both azo-dyes (CR and AM) degradation, the overall
mass balance in nitrogen was always found incomplete. Various experiments performed in pure oxygen in
a vacuum-tight cell and then in an air-free photoreactor (but filled with pure oxygen) enabled us to put in
evidence the formation of N2. Quantitative measurements clearly indicated that gaseous dinitrogen evolved
stoichiometrically corresponded to the mineralization of the central âN=Nâ azo-group. This constitutes the
ideal issue for the elimination of nitrogen-containing pollutants, not only for environmental photocatalysis
but also for any other physicochemical method. These results suggest that TiO2/UV photocatalysis may be
envisaged as a method for treatment of diluted colored waste waters not only for decolorization but also for
total detoxification, in particular in textile industries in semi-arid countries
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