Polysaccharide Blend Fibres Formed from NaOH, N-Methylmorpholine-N-oxide and 1-Ethyl-3-methylimidazolium acetate

Article disponible sur le site de l'éditeur : http://www.fibtex.lodz.pl/article330.htmlInternational audienceThe aim of the study was to find new structured biopolymer blends bearing adjustable properties able to produce innovative materials. Apart from cellulose and three solvents (NaOH, N-methylmorpholine-N-oxide [NMMO] and 1-ethyl-3-methylimidazolium acetate [EMIMac]), 15 different polysaccharides were chosen to study the interactions ofpolysaccharides or their mixtures in solutions, as well as the solid state after forming. Dissolution screenings yielded promising polysaccharides, which were used for the preparation of cellulose/ polysaccharide solutions and subsequently for the shaping of blends with cellulose. The solubility and miscibility were evaluated by microscopy, DSC, particle analysis and rheology. Polysaccharides with a structure similar to that of cellulose, e.g., xylan, carrageenan or cellulose carbamate were not miscible, showing globular morphologies, whereas high-molar and side chains containing polysaccharides such as xanthan or tragacanth gum form co-continuous morphologies. The forming of blend fibres was nevertheless possible for all three solvents. The textile-physical properties of the blend fibres were slightly decreased compared to those of the unmodified fibre, in which fibres from NMMO and EMIMac had the highest performance. The presence of blended polysaccharides in the fibres produced was verified by residue sugar analysis, in which the highest amounts occurred for EMIMac fibres

SOURCE 3: 1-year outcomes post-transcatheter aortic valve implantation using the latest generation of the balloon-expandable transcatheter heart valve

AIMS: Transcatheter aortic valve implantation (TAVI) has developed from a procedure for patients with aortic stenosis inoperable or high risk for surgery, into a treatment option even for intermediate risk elderly patients. This development has been facilitated by the clinical learning curve and constant improvements of transcatheter heart valves used. We present total 1-year results of SOURCE 3, the European post-approval multicentre registry of the latest generation balloon expandable SAPIEN 3TM (Edwards Lifesciences, Irvine, CA, USA). METHODS AND RESULTS: Participating centres have submitted their consecutive experience with the SAPIEN 3, dependent on patients consent. Data were prospectively collected and all end point-related outcomes adjudicated according to VARC-2 definitions by an independent committee. Between July 2014 and October 2015, in total 1946 patients (mean age 81.6\u2009\ub1\u20096.7\u2009years, 52% male) were enrolled in 80 centres from 10 European countries. At 1\u2009year, all-cause mortality was 12.6%, cardiovascular mortality 8.0%, stroke 3.1%, disabling stroke 1.4%, and rate of new pacemakers 13.2%. Causes of death were 62.0% cardiovascular and 38.0% non-cardiovascular, with heart failure (13.4%) and pulmonary complications (12.7%) being the main reasons for fatal outcomes. Multivariable analysis identified New York Heart Association Class IV and renal insufficiency as predictors of mortality, while higher BMI's improved survival. Severe (zero) and moderate paravalvular leakage (2.6%) was rare at 1\u2009year. CONCLUSION: In SOURCE 3, we observe a low complication rate and mortality at 1\u2009year. Given the low incidence of higher degree paravalvular leakages, this variable did no longer affect outcome. Clinicaltrial.gov number: NCT02698956

SOURCE 3 Registry Design and 30-Day Results of the European Postapproval Registry of the Latest Generation of the SAPIEN 3 Transcatheter Heart Valve

BACKGROUND: The SOURCE 3 Registry (SAPIEN Aortic Bioprosthesis European Outcome) is a European multicenter, observational registry of the latest generation of transcatheter heart valve, the SAPIEN 3 (Edwards Lifesciences, Irvine, CA). Its purpose is to document outcomes of clinical safety and performance after European approval was given. METHODS: Here, we present the 30-day outcome of the SOURCE 3 Registry. All data are self-reported, and all participating centers have committed to support their consecutive experience with the SAPIEN 3 transcatheter heart valve, dependent on patient consent, before the start of the study. Adverse events are defined with Valve Academic Research Consortium 2 criteria and adjudicated by an independent clinical events committee. RESULTS: A total of 1950 patients from 80 centers in 10 countries were enrolled between July 2014 and October 2015. Of those, 1947 patients underwent transcatheter aortic valve implantation (TAVI) with the SAPIEN 3 (mean age, 81.6 +/- 6.6 years; 48.1% female). Main comorbidities included coronary artery disease (51.5%), renal insufficiency (27.4%), diabetes mellitus (29.5%), chronic obstructive pulmonary disease (16.0%), and a mean logistic EuroSCORE of 18.3 +/- 13.2. Transfemoral access was used in 87.1% (n=1695); nontransfemoral, in 252 patients. Conscious sedation was used in 59.9% of transfemoral procedures, and in 50% of patients, TAVI was performed without aortic balloon valvuloplasty. Implantation success (1 valve in the intended location) was 98.3%. Conversion to conventional surgery (0.6%) and use of cardiopulmonary bypass (0.7%) were rare. Adverse events were low, with site-reported 30-day all-cause mortality of 2.2%, cardiovascular mortality of 1.1%, stroke of 1.4%, major vascular complications of 4.1%, life-threatening bleeding of 5%, and post-TAVI pacemaker implantation of 12%. Moderate or greater paravalvular regurgitation was observed in 3.1% of reporting patients. CONCLUSIONS: Results from the SOURCE 3 Registry demonstrate contemporary European trends and good outcomes of TAVI in daily practice when this third-generation TAVI device is used.Peer reviewe

Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≥20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≤pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≤{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

Search for displaced vertices arising from decays of new heavy particles in 7 TeV pp collisions at ATLAS

We present the results of a search for new, heavy particles that decay at a significant distance from their production point into a final state containing charged hadrons in association with a high-momentum muon. The search is conducted in a pp-collision data sample with a center-of-mass energy of 7 TeV and an integrated luminosity of 33 pb^-1 collected in 2010 by the ATLAS detector operating at the Large Hadron Collider. Production of such particles is expected in various scenarios of physics beyond the standard model. We observe no signal and place limits on the production cross-section of supersymmetric particles in an R-parity-violating scenario as a function of the neutralino lifetime. Limits are presented for different squark and neutralino masses, enabling extension of the limits to a variety of other models.Comment: 8 pages plus author list (20 pages total), 8 figures, 1 table, final version to appear in Physics Letters

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the polarisation of W bosons produced with large transverse momentum in pp collisions at sqrt(s) = 7 TeV with the ATLAS experiment

This paper describes an analysis of the angular distribution of W->enu and W->munu decays, using data from pp collisions at sqrt(s) = 7 TeV recorded with the ATLAS detector at the LHC in 2010, corresponding to an integrated luminosity of about 35 pb^-1. Using the decay lepton transverse momentum and the missing transverse energy, the W decay angular distribution projected onto the transverse plane is obtained and analysed in terms of helicity fractions f0, fL and fR over two ranges of W transverse momentum (ptw): 35 < ptw < 50 GeV and ptw > 50 GeV. Good agreement is found with theoretical predictions. For ptw > 50 GeV, the values of f0 and fL-fR, averaged over charge and lepton flavour, are measured to be : f0 = 0.127 +/- 0.030 +/- 0.108 and fL-fR = 0.252 +/- 0.017 +/- 0.030, where the first uncertainties are statistical, and the second include all systematic effects.Comment: 19 pages plus author list (34 pages total), 9 figures, 11 tables, revised author list, matches European Journal of Physics C versio

Observation of a new chi_b state in radiative transitions to Upsilon(1S) and Upsilon(2S) at ATLAS

The chi_b(nP) quarkonium states are produced in proton-proton collisions at the Large Hadron Collider (LHC) at sqrt(s) = 7 TeV and recorded by the ATLAS detector. Using a data sample corresponding to an integrated luminosity of 4.4 fb^-1, these states are reconstructed through their radiative decays to Upsilon(1S,2S) with Upsilon->mu+mu-. In addition to the mass peaks corresponding to the decay modes chi_b(1P,2P)->Upsilon(1S)gamma, a new structure centered at a mass of 10.530+/-0.005 (stat.)+/-0.009 (syst.) GeV is also observed, in both the Upsilon(1S)gamma and Upsilon(2S)gamma decay modes. This is interpreted as the chi_b(3P) system.Comment: 5 pages plus author list (18 pages total), 2 figures, 1 table, corrected author list, matches final version in Physical Review Letter

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