Influence of the Sodium/Proton replacement on the structural, morphological and photocatalytic properties of titanate nanotubes

Titanate nanotubes (TNT) with different sodium contents have been synthesised using a hydrothermal approach and a swift and highly controllable post-washing processes. The influence of the sodium/proton replacement on the structural and morphological characteristics of the prepared materials was analysed. Different optical behaviour was observed depending on the Na+/H+ samples’ content. A band gap energy of 3.27±0.03 eV was estimated for the material with higher sodium content while a value of 2.81±0.02 eV was inferred for the most protonated material, which therefore exhibits an absorption edge in the near visible region. The point of zero charge of the materials was determined and the influence of the sodium content on the adsorption of both cationic and anionic organic dyes was studied. The photocatalytic performance of the TNT samples was evaluated in the rhodamine 6G degradation process. Best photodegradation results were obtained when using the most protonated material as catalyst, although this material has shown the lowest R6G adsorption capability.

The expression in saccharomyces cerevisiae of a glucose/xylose symporter from Candida intermedia is affected by the presence of a glucose/xylose facilitator

Microbiology, 154

Generation of high-affinity monoclonal antibodies of IgG class against native β-d-glucans from basidiomycete mushrooms

β-d-glucans from basidiomycete strains are powerful immunomodulatory agents in several clinical conditions. Therefore, their assay, purification and characterization are of great interest to understand their structure-function relationship. Hybridoma cell fusion was used to raise monoclonal antibodies (Mabs) against extracellular β-d-glucans (EBGs) from Pleurotus ostreatus. Two of the hybridoma clones (1E6-1E8-B5 and 3E8-3B4) secreting Mabs against EBGs were selected. This hybridoma cell line secreted Mabs of the IgG class which were then purified by hydroxyapatite chromatography to apparent homogeneity on native and SDS-PAGE. Mabs secreted by 1E6-1E8-B5 clone were found to recognize a common epitope on several β-d-glucans from different basidiomycete strains. This Mab exhibited high affinity constant (KA) for β-d-glucans from several mushroom strains in the range of 3.20 × 109 ± 3.32 × 103-1.51 × 1013 ± 3.58 × 107 L/mol. Moreover, they reacted to some heat-treated β-d-glucans in a different mode when compared with the native forms; these data suggest that this Mab binds to a conformational epitope on the β-d-glucan molecule. The epitope-binding studies of Mabs obtained from 1E6-1E8-B5 and 3E8-3B4 revealed that the Mabs bind to the same epitope on some β-d-glucans and to different epitopes in other antigen molecules. Therefore, these Mabs can be used to assay for β-d-glucan from basidiomycete mushrooms. © 2015 Elsevier Ltd. All rights reserved.

Affinity and diversity indices for anopheline immature forms

As for the entire Amazon Region, malaria continues to be a major health public problem in Roraima that presented an Annual Parasitic Index of 85.4 in 2005, the highest in Brazil. Information on anopheline breeding sites is an essential component in malaria control strategies. Aiming to contribute to the limited knowledge on anopheline immature forms in Roraima, collections and breeding site observations were performed in 10 breeding sites around the capital city Boa Vista. Collections were carried out in the rainy and dry season periods between April 2004 and January 2005. Breeding sites comprised natural and artificial water reservoirs. A total of 623 immature forms were collected belonging to Anopheles albitarsis s.l., An.triannulatus s.l., An. nuneztovari/dunhami, An. braziliensis, An. evansae, An. oswaldoi s.l., An. strodei and An. darlingi. An. albitarsis and An. braziliensis were the most frequently found species. Eight larvae of An. darlingi were found in only one breeding site located in the forest. An. triannulatus/An. nuneztovari and An. albitarsis/An. braziliensis were the pairs of species that mostly occurred together. Both pair of species displayed the highest affinity index what might indicate a high compatibility for the same breeding conditions and/or a synergistic co-occurrence. Species diversity index was higher for the dry season.

Preparation of affinity membranes using alternative solvents

Dissertação apresentada na Faculdade de Ciências e Tecnologia da Universidade Nova de Lisboa para obtenção do grau de Mestre em Mestrado Integrado em Engenharia Química e Bioquímica

Development of an affinity pair “Tag-Receptor” for recombinant protein expression and purification

Dissertação apresentada para a obtenção do Grau de Mestre em Biotecnologia, pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Novel affinity pairs "tag-receptor" for the purification of fusion proteins

Fundação para a Ciência e Tecnologia - SFRH/BD/48804/2008 and the project PTDC/BI/65383/2006 assigned to Prof. Cecíla Roque and also to Associate Laboratory REQUIMTE (Pest-C/EQB/LA0006/2011)

Factors affecting Helicobacter pylori eradication using a seven-day triple therapy with a proton pump inhibitor, tinidazole and clarithromycin, in brazilian patients with peptic ulcer

Triple therapy is accepted as the treatment of choice for H. pylori eradication. In industrialized countries, a proton pump inhibitor plus clarithromycin and amoxicillin or nitroimidazole have shown the best results. Our aims were: 1. To study the eradication rate of the association of a proton pump inhibitor plus tinidazole and clarithromycin on H. pylori infection in our population. 2. To determine if previous treatments, gender, age, tobacco, alcohol use, and non-steroidal anti-inflammatory drugs (NSAIDs) change the response to therapy. METHODS: Two hundred patients with peptic ulcer (upper endoscopy) and H. pylori infection (histology and rapid urease test - RUT) were included. A proton pump inhibitor (lansoprazole 30 mg or omeprazole 20 mg), tinidazole 500 mg, and clarithromycin 250 mg were dispensed twice a day for a seven-day period. Eradication was assessed after 10 to 12 weeks of treatment through histology and RUT. RESULTS: The eradication rate of H. pylori per protocol was 65% (128/196 patients). This rate was 53% for previously treated patients, rising to 76% for not previously treated patients, with a statistical difference p<0.01. No significant difference was observed regarding sex, tobacco use, alcohol consumption, and NSAID use, but for elderly patients the difference was p = 0.05. Adherence to treatment was good, and side effects were mild. CONCLUSIONS: A proton pump inhibitor, tinidazole, and clarithromycin bid for seven days resulted in H. pylori eradication in 65% of the patients. Previous treatments were the main cause of treatment failure.

Proton magnetic resonance spectroscopy of the frontal lobe in schizophrenics: a critical review of the methodology

Schizophrenic patients undergoing proton magnetic resonance spectroscopy show alterations in N-acetyl aspartate levels in several brain regions, indicating neuronal dysfunction. The present review focuses on the main proton magnetic resonance spectroscopy studies in the frontal lobe of schizophrenics. A MEDLINE search, from 1991 to March 2004, was carried out using the key-words spectroscopy and schizophrenia and proton and frontal. In addition, articles cited in the reference list of the studies obtained through MEDLINE were included. As a result, 27 articles were selected. The results were inconsistent, 19 papers reporting changes in the N-acetyl aspartate levels, while 8 reported no change. Methodological analysis led to the conclusion that the discrepancy may be due the following factors: (i) number of participants; (ii) variation in the clinical and demographic characteristics of the groups; (iii) little standardization of the acquisition parameters of spectroscopy. Overall, studies that fulfill strict methodological criteria show N-acetyl aspartate decrease in the frontal lobe of male schizophrenics.

Jet energy measurement and its systematic uncertainty in proton-proton collisions at s√=7 TeV with the ATLAS detector

The jet energy scale (JES) and its systematic uncertainty are determined for jets measured with the ATLAS detector using proton–proton collision data with a centre-of-mass energy of s√=7 TeV corresponding to an integrated luminosity of 4.7 fb −1 . Jets are reconstructed from energy deposits forming topological clusters of calorimeter cells using the anti- kt algorithm with distance parameters R=0.4 or R=0.6 , and are calibrated using MC simulations. A residual JES correction is applied to account for differences between data and MC simulations. This correction and its systematic uncertainty are estimated using a combination of in situ techniques exploiting the transverse momentum balance between a jet and a reference object such as a photon or a Z boson, for 20≤pjetT<1000 GeV and pseudorapidities |η|<4.5 . The effect of multiple proton–proton interactions is corrected for, and an uncertainty is evaluated using in situ techniques. The smallest JES uncertainty of less than 1 % is found in the central calorimeter region ( |η|<1.2 ) for jets with 55≤pjetT<500 GeV . For central jets at lower pT , the uncertainty is about 3 %. A consistent JES estimate is found using measurements of the calorimeter response of single hadrons in proton–proton collisions and test-beam data, which also provide the estimate for pjetT>1 TeV. The calibration of forward jets is derived from dijet pT balance measurements. The resulting uncertainty reaches its largest value of 6 % for low- pT jets at |η|=4.5 . Additional JES uncertainties due to specific event topologies, such as close-by jets or selections of event samples with an enhanced content of jets originating from light quarks or gluons, are also discussed. The magnitude of these uncertainties depends on the event sample used in a given physics analysis, but typically amounts to 0.5–3 %.

Measurement of the top pair production cross-section in 8 TeV proton-proton collisions using kinematic information in the lepton+jets final state with ATLAS

A measurement is presented of the tt¯ inclusive production cross section in pp collisions at a center-of-mass energy of s√=8  TeV using data collected by the ATLAS detector at the CERN Large Hadron Collider. The measurement was performed in the lepton+jets final state using a data set corresponding to an integrated luminosity of 20.3  fb−1. The cross section was obtained using a likelihood discriminant fit and b-jet identification was used to improve the signal-to-background ratio. The inclusive tt¯ production cross section was measured to be 260±1(stat)+22−23(stat)±8(lumi)±4(beam)  pb assuming a top-quark mass of 172.5 GeV, in good agreement with the theoretical prediction of 253+13−15  pb. The tt¯→(e,μ)+jets production cross section in the fiducial region determined by the detector acceptance is also reported.

Centrality and rapidity dependence of inclusive jet production in sNN=5.02 TeV proton-lead collisions with the ATLAS detector

Measurements of the centrality and rapidity dependence of inclusive jet production in sNN−−−√=5.02 TeV proton--lead (p+Pb) collisions and the jet cross-section in s√=2.76 TeV proton--proton collisions are presented. These quantities are measured in datasets corresponding to an integrated luminosity of 27.8 nb−1 and 4.0 pb−1, respectively, recorded with the ATLAS detector at the Large Hadron Collider in 2013. The p+Pb collision centrality was characterised using the total transverse energy measured in the pseudorapidity interval −4.9<η<−3.2 in the direction of the lead beam. Results are presented for the double-differential per-collision yields as a function of jet rapidity and transverse momentum (pT) for minimum-bias and centrality-selected p+Pb collisions, and are compared to the jet rate from the geometric expectation. The total jet yield in minimum-bias events is slightly enhanced above the expectation in a pT-dependent manner but is consistent with the expectation within uncertainties. The ratios of jet spectra from different centrality selections show a strong modification of jet production at all pT at forward rapidities and for large pT at mid-rapidity, which manifests as a suppression of the jet yield in central events and an enhancement in peripheral events. These effects imply that the factorisation between hard and soft processes is violated at an unexpected level in proton--nucleus collisions. Furthermore, the modifications at forward rapidities are found to be a function of the total jet energy only, implying that the violations may have a simple dependence on the hard parton--parton kinematics.

Measurement of the transverse polarization of Λ and Λ ¯ hyperons produced in proton-proton collisions at s =7TeV using the ATLAS detector

The transverse polarization of Λ and Λ¯ hyperons produced in proton--proton collisions at a center-of-mass energy of 7 TeV is measured. The analysis uses 760 μb−1 of minimum bias data collected by the ATLAS detector at the LHC in the year 2010. The measured transverse polarization averaged over Feynman xF from 5×10−5 to 0.01 and transverse momentum pT from 0.8 to 15 GeV is −0.010±0.005(stat)±0.004(syst) for Λ and 0.002±0.006(stat)±0.004(syst) for Λ¯. It is also measured as a function of xF and pT, but no significant dependence on these variables is observed. Prior to this measurement, the polarization was measured at fixed-target experiments with center-of-mass energies up to about 40 GeV. The ATLAS results are compatible with the extrapolation of a fit from previous measurements to the xF range covered by this mesurement.

The effects of solvent composition on the affinity of a peptide towards hair keratin: experimental and molecular dynamics data

The study of the interaction between hair filaments and formulations or peptides is of utmost importance in fields like cosmetic research. Keratin intermediate filaments structure is not fully described, limiting the molecular dynamics (MD) studies in this field although its high potential to improve the area. We developed a computational model of a truncated protofibril, simulated its behavior in alcoholic based formulations and with one peptide. The simulations showed a strong interaction between the benzyl alcohol molecules of the formulations and the model, leading to the disorganization of the keratin chains, which regress with the removal of the alcohol molecules. This behavior can explain the increase of peptide uptake in hair shafts evidenced in fluorescence microscopy pictures. The model developed is valid to computationally reproduce the interaction between hair and alcoholic formulations and provide a robust base for new MD studies about hair properties. It is shown that the MD simulations can improve hair cosmetic research, improving the uptake of a compound of interest.

Search for s-channel single top-quark production in proton-proton collisions at s√=8 TeV with the ATLAS detector

This Letter presents a search at the LHC for s-channel single top-quark production in proton-proton collisions at a centre-of-mass energy of 8 TeV. The analyzed data set was recorded by the ATLAS detector and corresponds to an integrated luminosity of 20.3 fb−1. Selected events contain one charged lepton, large missing transverse momentum and exactly two b-tagged jets. A multivariate event classifier based on boosted decision trees is developed to discriminate s-channel single top-quark events from the main background contributions. The signal extraction is based on a binned maximum-likelihood fit of the output classifier distribution. The analysis leads to an upper limit on the s-channel single top-quark production cross-section of 14.6 pb at the 95% confidence level. The fit gives a cross-section of σs=5.0±4.3 pb, consistent with the Standard Model expectation.