Effect of introducing a cationic system into a thiol‐ene photopolymerizable formulation

Hybrid materials derived from a thiol‐ene and cationic polymerization were obtained from concomitant polymerization. The hybrid materials were cured by both photopolymerization and thermally induced polymerization. The kinetics of the photopolymerization were measured using time resolved‐IR and optical pyrometry. The nucleophilic character of the polysulfide obtained initially in the thiol‐ene polymerization inhibited the development of the cationic photoinitiated polymerization of epoxy monomers. Besides, the epoxide groups underwent a proton catalyzed addition reaction with the thiols to form new sulfides groups in the reaction mixture. It is proposed that the formed sulfides can terminate the growing polyether chains forming dormant species like trialkylsulfonium salts. These salts promote the thermal polymerization of the epoxy monomer in a post treatment, producing hard and transparent materials. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4829–4843, 2007     

Discretization and best approximation in Besov spaces

In this paper we prove a theorem about existence of best approximation in a class of spaces involving Besov spaces, via a discretization technique. It is a consequence of this theorem that rational functions and exponencial sums are proximinal subsets of B _∞,q ^a (π). It is also proved the proximinality of R _m ⁿ [a, b] in B _p,q ^a (π) for arbitrary p,q and a.     

Sodium dodecyl sulfate free gel electrophoresis/electroelution sorting for peptide fractionation

Shotgun proteomics based on peptide fractionation by using liquid chromatography has become the common procedure for proteomic studies, although in the very beginning of the field, protein separation by using electrophoresis was the main tool. Nonetheless, during the last two decades, the electrophoretic techniques for peptide mixtures fractionation have evolved as a result of relevant technological improvements. We also proposed the combination of sodium dodecyl sulfate polyacrylamide gel electrophoresis for protein fractionation and sodium dodecyl sulfate free polyacrylamide gel electrophoresis for peptide separation as a novel procedure for proteomic studies. Here, we present an optimized device for sodium dodecyl sulfate free polyacrylamide gel electrophoresis improving peptide recoveries respect to the established electrophoretic technique off gel electrophoresis meanwhile conserving the excellent resolution described for the former technique in slab gel based systems. The device simultaneously allows the separation and the collection of fractionated peptides in solution.     

Revisit to Two-Proton Radioactivity of 19Mg and Observation of Two-Proton Decay of 30Ar

An experiment aimed to investigate the two-proton (2p) decay of the previously unknown nucleus 30Ar was performed at GSI: By tracking the decay products in-flight with silicon micro-strip detectors, the 2p decays of 30Ar were observed for the first time. For the calibration purpose, 2p decays of 19Mg were also remeasured by tracking the coincident 17Ne+p+p trajectories. By comparing the measured angular p-17Ne correlations with those obtained from the corresponding Monte Carlo simulations, the simultaneous 2p decay of 19Mg ground state and the sequential 2p emission of several known excited states of 19Mg were confirmed. One new excited state in 19Mg and two new excited states in 18Na were observed.     

Search for new physics in photon-lepton events in pp collisions at sqrt[s] = 1.8 TeV

We present the results of a search in pp collisions at sqrt[s] = 1.8 TeV for anomalous production of events containing a photon and a lepton (e or mu), both with large transverse energy, using 86 pb(-1) of data collected with the Collider Detector at Fermilab during the 1994-1995 collider run at the Fermilab Tevatron. The presence of large missing transverse energy (E(T)), additional photons, or additional leptons in these events is also analyzed. The results are consistent with standard model expectations, with the possible exception of photon-lepton events with large E(T), for which the observed total is 16 events and the expected mean total is 7.6+/-0.7 events.     

Observation of the narrow state X(3872)-->J/psipi+pi- in pp collisions at sqaure root of s=1.96 TeV

We report the observation of a narrow state decaying into J/psipi+pi- and produced in 220 pb(-1) of p p-bar collisions at =1.96 Tesqaure root of sV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c2, with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson.     

Search for anomalous kinematics in tt dilepton events at CDF II

We report on a search for anomalous kinematics of tt dilepton events in pp collisions at square root of s=1.96 TeV using 193 pb(-1) of data collected with the CDF II detector. We developed a new a priori technique designed to isolate the subset in a data sample revealing the largest deviation from standard model (SM) expectations and to quantify the significance of this departure. In the four-variable space considered, no particular subset shows a significant discrepancy, and we find that the probability of obtaining a data sample less consistent with the SM than what is observed is 1.0%-4.5%.     

First measurements of inclusive W and Z cross sections from run II of the fermilab tevatron collider

We report the first measurements of inclusive W and Z cross sections times leptonic branching ratios for pp collisions at square root[s]=1.96 TeV, based on their decays to electrons and muons. The data correspond to an integrated luminosity of 72 pb(-1) recorded with the CDF detector at the Fermilab Tevatron. We test e-mu universality in W decays, and we measure the ratio of leptonic W and Z rates from which the leptonic branching fraction B(W-->lnu) can be extracted as well as an indirect value for the total width of the W and the Cabibbo-Kobayashi-Maskawa matrix element, |V(cs)|.