Biocatalytic CO2 absorption and structural studies of carbonic anhydrase under industrially-relevant conditions

UIDB/50006/2020 IF/00505/2014/CP1224/CT0004The unprecedently high CO2 levels in the atmosphere evoke the urgent need for development of technologies for mitigation of its emissions. Among the alternatives, the biocatalytic route has been claimed as one of the most promising. In the present work, the carbonic anhydrase from bovine erythrocytes (BCA) was employed as a model enzyme for structural studies in an aqueous phase at alkaline pH, which is typical of large-scale absorption processes under operation. Circular dichroism (CD) analysis revealed a high enzymatic stability at pH 10 with a prominent decrease of the melting temperature above this value. The CO2 absorption capacity of the aqueous solutions were assessed by online monitoring of pressure decay in a stainless-steel cell, which indicated a better performance at pH 10 with a kinetic rate increase of up to 43%, as compared to non-biocatalytic conditions. Even low enzyme concentrations (0.2 mg g−1) proved to be sufficient to improve the overall CO2 capture process performance. The enzyme-enhanced approach of CO2 capture presents a high potential and should be further studied.publishersversionpublishe

Implantation of intracorneal ring segments in pediatric patients: long-term follow-up

Purpose: To analyze the long-term outcomes of intracorneal ring segments (ICRS) implantation for keratoconus management in pediatric patients. Methods: Retrospective case series review of the long-term (>5 years) outcomes of Intacs® ICRS implantation for keratoconus in pediatric patients (age <18 years old at the time of surgery) between January 2008 and December 2011 at Ophthalmology Department of Hospital de Santo António. Demographic data, follow-up time, preoperative and postoperative uncorrected visual acuity (UCVA) and best-corrected visual acuity (BCVA) in decimal scale, and corneal topography were evaluated. Statistical analysis was done using SPSS for windows (version 24). Significance was set at p<0.0125. Results: Fourteen eyes of 14 patients, with a mean age of 15.36 years (range 10-18 years), were included in this study. All patients had been diagnosed with keratoconus with reported progression in the 6 months prior to surgery. Follow-up time was 6.36±0.97 years. UCVA and BCVA improved after ICRS implantation (p<0.0125). Keratometry (K) minimum (Kmin) and K maximum (Kmax) decreased after surgery (p<0.0125). During follow-up, UCVA, BCVA, Kmin, and Kmax values ranged, showing a tendency to worsen at the end of follow-up. However, statistically significant differences were not observed. Conclusion: ICRS implantation showed good visual and topographic results in pediatric patients. Long-term follow-up suggests that, despite ICRS implantation, there is still progression of keratoconus. To the best of our knowledge, there are no reports regarding the long-term efficacy of ICRS implantation in pediatric patients.info:eu-repo/semantics/publishedVersio

Improved syntheses of aromatase inhibitors and neuroactive steroids efficient oxidations and reductions at key positions for bioactivity

An Henbest reduction, followed by the preparation of a silyl enol ether and oxidation in situ with m-CPBA has led to the neurosteroids 3[alpha]-hydroxy- and 3[alpha],21-dihydroxy-5[alpha]-pregnanolones. Using testosterone as starting material, a new short synthesis of an aromatase inhibitor, 4-OHA, has been achieved through hydroboration/oxidation followed by a Swern type oxidation and epimerization. Another aromatase inhibitor, androst-4-ene-3,6-17-trione, has been efficiently prepared using PCC on montmorillonite K10, under ultrasonic irradiation.http://www.sciencedirect.com/science/article/B6THR-3WC46V7-8/1/5f915790e78df65f4c988ab78bf4f17

Trypanosoma brucei parasites occupy and functionally adapt to the adipose tissue in mice

This work was supported by 55007419 (HHMI) and 2151 (EMBO) to L.M.F., D.P.-N., F.B., and F.G.; FCT fellowships to S.T., F.R.-F., and F.A.-B. (SFRH/BPD/89833/2012, SFRH/BD/51286/2010, and SFRH/BD/80718/2011, respectively); Wellcome Trust grant (093228), MRC MR/M020118/1, and European Community Seventh Framework Programme under grant agreement No. 602773 (Project KINDRED) to S.A.Y. and T.K.S.; and PAI 7/41 (Belspo) and ERC-NANOSYM to J.V.D.A.Trypanosoma brucei is an extracellular parasite that causes sleeping sickness. In mammalian hosts, trypanosomes are thought to exist in two major niches: early in infection, they populate the blood; later, they breach the blood-brain barrier. Working with a well-established mouse model, we discovered that adipose tissue constitutes a third major reservoir for T. brucei. Parasites from adipose tissue, here termed adipose tissue forms (ATFs), can replicate and were capable of infecting a naive animal. ATFs were transcriptionally distinct from bloodstream forms, and the genes upregulated included putative fatty acid β-oxidation enzymes. Consistent with this, ATFs were able to utilize exogenous myristate and form β-oxidation intermediates, suggesting that ATF parasites can use fatty acids as an external carbon source. These findings identify the adipose tissue as a niche for T. brucei during its mammalian life cycle and could potentially explain the weight loss associated with sleeping sickness.Publisher PDFPeer reviewe

Hunt for new phenomena using large jet multiplicities and missing transverse momentum with ATLAS in 4.7 fb−1 of s√=7TeV proton-proton collisions

Results are presented of a search for new particles decaying to large numbers of jets in association with missing transverse momentum, using 4.7 fb−1 of pp collision data at s√=7TeV collected by the ATLAS experiment at the Large Hadron Collider in 2011. The event selection requires missing transverse momentum, no isolated electrons or muons, and from ≥6 to ≥9 jets. No evidence is found for physics beyond the Standard Model. The results are interpreted in the context of a MSUGRA/CMSSM supersymmetric model, where, for large universal scalar mass m 0, gluino masses smaller than 840 GeV are excluded at the 95% confidence level, extending previously published limits. Within a simplified model containing only a gluino octet and a neutralino, gluino masses smaller than 870 GeV are similarly excluded for neutralino masses below 100 GeV

Measurements of Higgs boson production and couplings in diboson final states with the ATLAS detector at the LHC

Measurements are presented of production properties and couplings of the recently discovered Higgs boson using the decays into boson pairs, H →γ γ, H → Z Z∗ →4l and H →W W∗ →lνlν. The results are based on the complete pp collision data sample recorded by the ATLAS experiment at the CERN Large Hadron Collider at centre-of-mass energies of √s = 7 TeV and √s = 8 TeV, corresponding to an integrated luminosity of about 25 fb−1. Evidence for Higgs boson production through vector-boson fusion is reported. Results of combined fits probing Higgs boson couplings to fermions and bosons, as well as anomalous contributions to loop-induced production and decay modes, are presented. All measurements are consistent with expectations for the Standard Model Higgs boson

Standalone vertex finding in the ATLAS muon spectrometer

A dedicated reconstruction algorithm to find decay vertices in the ATLAS muon spectrometer is presented. The algorithm searches the region just upstream of or inside the muon spectrometer volume for multi-particle vertices that originate from the decay of particles with long decay paths. The performance of the algorithm is evaluated using both a sample of simulated Higgs boson events, in which the Higgs boson decays to long-lived neutral particles that in turn decay to bbar b final states, and pp collision data at √s = 7 TeV collected with the ATLAS detector at the LHC during 2011

Measurement of the top quark-pair production cross section with ATLAS in pp collisions at \sqrt{s}=7\TeV

A measurement of the production cross-section for top quark pairs(\ttbar) in $pp$ collisions at \sqrt{s}=7 \TeV is presented using data recorded with the ATLAS detector at the Large Hadron Collider. Events are selected in two different topologies: single lepton (electron $e$ or muon $\mu$) with large missing transverse energy and at least four jets, and dilepton ($ee$, $\mu\mu$ or $e\mu$) with large missing transverse energy and at least two jets. In a data sample of 2.9 pb-1, 37 candidate events are observed in the single-lepton topology and 9 events in the dilepton topology. The corresponding expected backgrounds from non-\ttbar Standard Model processes are estimated using data-driven methods and determined to be $12.2 \pm 3.9$ events and $2.5 \pm 0.6$ events, respectively. The kinematic properties of the selected events are consistent with SM \ttbar production. The inclusive top quark pair production cross-section is measured to be \sigmattbar=145 \pm 31 ^{+42}_{-27} pb where the first uncertainty is statistical and the second systematic. The measurement agrees with perturbative QCD calculations.Comment: 30 pages plus author list (50 pages total), 9 figures, 11 tables, CERN-PH number and final journal adde

Measurement of the top quark pair cross section with ATLAS in pp collisions at √s=7 TeV using final states with an electron or a muon and a hadronically decaying τ lepton

A measurement of the cross section of top quark pair production in proton-proton collisions recorded with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 7 TeV is reported. The data sample used corresponds to an integrated luminosity of 2.05 fb -1. Events with an isolated electron or muon and a τ lepton decaying hadronically are used. In addition, a large missing transverse momentum and two or more energetic jets are required. At least one of the jets must be identified as originating from a b quark. The measured cross section, σtt-=186±13(stat.)±20(syst.)±7(lumi.) pb, is in good agreement with the Standard Model prediction