Microwave pretreatment of lignocellulosic biomass to release maximum phenolic acids

[EN] The objectives fixed by world’s governments concerning energy transition have aroused interest on lignocellulosic biomass utilization for bioenergy and green chemistry applications. However, due to their resistant structure, deconstructive pretreatments are necessary to render possible biological conversions of these lignocellulosic residues. Microwave (MW) treatment has been reported as efficient in many biotechnology fields; biomass pretreatment for biorefinery purposes is another possible application. This work presents the effects of MW pretreatment on underexploited natural agri-food biomass of economic interest: wheat bran, miscanthus stalks and corn stalks. Various parameters were studied including solvent, power density, treatment duration, pressure. Effects were evaluated by a complete biomass characterization before and after treatment, with main focus on phenolic acids release. In the tested conditions and when compared to the high NaOH consumption reference extraction method for phenolic acids, the atmospheric pressure (open vessel) microwave treatment did not allow attaining high acid yields (Fig.1). The most important parameters for improving treatment efficiency were power density and solvent. In order to increase yields, microwave treatments under pressure were carried out to reach higher temperatures while taking care as to not exceed the acid denaturation temperature (150°C) and to avoid the formation of inhibitors. Phenolic acids yields and biomass composition are currently being processed and will be discussed.Authors would like to thank Nicolas Holfeltz, NH Verre France for his help in designing the microwave reactor. The authors also thank Yannick Sire from INRA Pech Rouge for phenolic acids analysis.Bichot, A.; Radoiu, M.; Bernet, N.; Mechin, V.; Delgenès, J.; García Bernet, D. (2019). Microwave pretreatment of lignocellulosic biomass to release maximum phenolic acids. En AMPERE 2019. 17th International Conference on Microwave and High Frequency Heating. Editorial Universitat Politècnica de València. 182-188. https://doi.org/10.4995/AMPERE2019.2019.9629OCS18218

The phase spiral in Gaia DR3

We aim to study the phase spiral in the Milky Way (MW) with Gaia DR3. We used an edge detection algorithm to find the border of the phase spiral, allowing us to robustly quantify its shape at different positions and for different selections. We calculated the time of onset of the phase-mixing by determining the different turns of the phase spiral and using the vertical frequencies from commonly used MW potential models. We find that the phase spiral extends down to $-1.2$ kpc in height below the plane (about 3 to 5 scale heights of the thin disc) and beyond $\pm 50$ km/s in $V_Z$. We see a secondary branch mostly at positive vertical velocities when coloured by azimuthal velocity and in the counts projection. We also find complex variations of the phase spirals with angular momentum and azimuth. All these possibly provide evidence of multiple perturbations (from different times or from different perturbers) and/or of the complexity of the phase mixing process. We detect the phase spiral from 6 to 11 kpc from the Galactic centre and find signatures of vertical asymmetries 1-2 kpc beyond this range. We measure small but clear variations with azimuth. When we determine the phase mixing times from the phase spiral at different angular momenta and using the different spiral turns (at different $Z$) we obtain inconsistent times with systematic differences (times increasing with $|L_Z|$ and with $|Z|$). Our determinations are mostly in the range of [0.3-0.9] Gyr, with an average of 0.5 Gyr. The inconsistencies do not change when using different usual potential models, different stellar distances or frequencies for different kinetic temperatures. They could stem from the inconsistency of potential models with the true MW, and from too simple modelling, in particular neglecting self-gravity, not considering the multiple perturbations and the interference with other processes.Comment: accepted for publication in A&

Características de una población de personas con diabetes mellitus en un programa de enfermedades crónicas

1 p.Objetivo: describir características clínicas de personas con Diabetes Mellitus de un programa de seguimiento.http://www.revista.fcm.unc.edu.ar/jornadas.pdfFil: Aguirre, Ana Noemí. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas; Argentina.Fil: López, Ana Cristina. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: Roitter, Claudia Valentina. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: Mantaras, José. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: García, Adelaida. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: Cecchetto, Eugenio. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: Bernet, Jorgelina. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Fil: Aguirre, Jorge Alberto. Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Cátedra de Farmacología Aplicada I y II; Argentina.Epidemiologí

Influence of Metal, Ligand and Solvent on Supramolecular Polymerizations with Transition-Metal Compounds: A Theoretical Study

The nature of intermolecular interactions governing supramolecular polymerizations is very important to control their cooperativity. In order to address this problem, supramolecular columns made of Pt(II) and Pd(II) complexes of oligo(phenyleneethynylene)-based pyridine (OPE) and tetrazolyl-pyridine ligands (TEP) were investigated through the dispersion-corrected PM6 method. Aromatic, CH-π, M-Cl and metallophilic interactions helped stabilize the supramolecules studied, and their geometries and associated cooperativities were in excellent agreement with experimental data. The OPE ligand and/or the presence of Pt(II) have led to stronger metallophilic interactions and also to cooperative supramolecular polymerizations, which clearly suggests that metallophilic interactions are a key factor to control cooperativity. The results indicate that sequential monomer addition is in general less spontaneous than the combination of two larger pre-formed stacks. The present theoretical investigations contribute to the further understanding of the relation between the thermodynamics of supramolecular polymerizations and the nature of different synthons

Non invasive ventilation after extubation in paediatric patients: a preliminary study

<p>Abstract</p> <p>Background</p> <p>Non-invasive ventilation (NIV) may be useful after extubation in children. Our objective was to determine postextubation NIV characteristics and to identify risk factors of postextubation NIV failure.</p> <p>Methods</p> <p>A prospective observational study was conducted in an 8-bed pediatric intensive care unit (PICU). Following PICU protocol, NIV was applied to patients who had been mechanically ventilated for over 12 hours considered at high-risk of extubation failure -elective NIV (eNIV), immediately after extubation- or those who developed respiratory failure within 48 hours after extubation -rescue NIV (rNIV)-. Patients were categorized in subgroups according to their main underlying conditions. NIV was deemed successful when reintubation was avoided. Logistic regression analysis was performed in order to identify predictors of NIV failure.</p> <p>Results</p> <p>There were 41 episodes (rNIV in 20 episodes). Success rate was 50% in rNIV and 81% in eNIV (p = 0.037). We found significant differences in univariate analysis between success and failure groups in respiratory rate (RR) decrease at 6 hours, FiO₂at 1 hour and PO₂/FiO₂ratio at 6 hours. Neurologic condition was found to be associated with NIV failure. Multiple logistic regression analysis identified no variable as independent NIV outcome predictor.</p> <p>Conclusions</p> <p>Our data suggest that postextubation NIV seems to be useful in avoiding reintubation in high-risk children when applied immediately after extubation. NIV was more likely to fail when ARF has already developed (rNIV), when RR at 6 hours did not decrease and if oxygen requirements increased. Neurologic patients seem to be at higher risk of reintubation despite NIV use.</p

Observation of two new Ξb−\Xi_b^- baryon resonances

Two structures are observed close to the kinematic threshold in the $\Xi_b^0 \pi^-$ mass spectrum in a sample of proton-proton collision data, corresponding to an integrated luminosity of 3.0 fb$^{-1}$ recorded by the LHCb experiment. In the quark model, two baryonic resonances with quark content $bds$ are expected in this mass region: the spin-parity $J^P = \frac{1}{2}^+$ and $J^P=\frac{3}{2}^+$ states, denoted $\Xi_b^{\prime -}$ and $\Xi_b^{*-}$. Interpreting the structures as these resonances, we measure the mass differences and the width of the heavier state to be $m(\Xi_b^{\prime -}) - m(\Xi_b^0) - m(\pi^{-}) = 3.653 \pm 0.018 \pm 0.006$ MeV$/c^2$, $m(\Xi_b^{*-}) - m(\Xi_b^0) - m(\pi^{-}) = 23.96 \pm 0.12 \pm 0.06$ MeV$/c^2$, $\Gamma(\Xi_b^{*-}) = 1.65 \pm 0.31 \pm 0.10$ MeV, where the first and second uncertainties are statistical and systematic, respectively. The width of the lighter state is consistent with zero, and we place an upper limit of $\Gamma(\Xi_b^{\prime -}) < 0.08$ MeV at 95% confidence level. Relative production rates of these states are also reported.Comment: 17 pages, 2 figure

Measurement of the mass and lifetime of the Ωb−\Omega_b^- baryon

A proton-proton collision data sample, corresponding to an integrated luminosity of 3 fb$^{-1}$ collected by LHCb at $\sqrt{s}=7$ and 8 TeV, is used to reconstruct $63\pm9$ $\Omega_b^-\to\Omega_c^0\pi^-$, $\Omega_c^0\to pK^-K^-\pi^+$ decays. Using the $\Xi_b^-\to\Xi_c^0\pi^-$, $\Xi_c^0\to pK^-K^-\pi^+$ decay mode for calibration, the lifetime ratio and absolute lifetime of the $\Omega_b^-$ baryon are measured to be \begin{align*} \frac{\tau_{\Omega_b^-}}{\tau_{\Xi_b^-}} &= 1.11\pm0.16\pm0.03, \\ \tau_{\Omega_b^-} &= 1.78\pm0.26\pm0.05\pm0.06~{\rm ps}, \end{align*} where the uncertainties are statistical, systematic and from the calibration mode (for $\tau_{\Omega_b^-}$ only). A measurement is also made of the mass difference, $m_{\Omega_b^-}-m_{\Xi_b^-}$, and the corresponding $\Omega_b^-$ mass, which yields \begin{align*} m_{\Omega_b^-}-m_{\Xi_b^-} &= 247.4\pm3.2\pm0.5~{\rm MeV}/c^2, \\ m_{\Omega_b^-} &= 6045.1\pm3.2\pm 0.5\pm0.6~{\rm MeV}/c^2. \end{align*} These results are consistent with previous measurements.Comment: 11 pages, 5 figures, All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-008.htm

Study of B−→DK−π+π−B^{-}\to DK^-\pi^+\pi^- and B−→Dπ−π+π−B^-\to D\pi^-\pi^+\pi^- decays and determination of the CKM angle γ\gamma

We report a study of the suppressed $B^-\to DK^-\pi^+\pi^-$ and favored $B^-\to D\pi^-\pi^+\pi^-$ decays, where the neutral $D$ meson is detected through its decays to the $K^{\mp}\pi^{\pm}$ and CP-even $K^+K^-$ and $\pi^+\pi^-$ final states. The measurement is carried out using a proton-proton collision data sample collected by the LHCb experiment, corresponding to an integrated luminosity of 3.0~fb$^{-1}$. We observe the first significant signals in the CP-even final states of the $D$ meson for both the suppressed $B^-\to DK^-\pi^+\pi^-$ and favored $B^-\to D\pi^-\pi^+\pi^-$ modes, as well as in the doubly Cabibbo-suppressed $D\to K^+\pi^-$ final state of the $B^-\to D\pi^-\pi^+\pi^-$ decay. Evidence for the ADS suppressed decay $B^{-}\to DK^-\pi^+\pi^-$, with $D\to K^+\pi^-$, is also presented. From the observed yields in the $B^-\to DK^-\pi^+\pi^-$, $B^-\to D\pi^-\pi^+\pi^-$ and their charge conjugate decay modes, we measure the value of the weak phase to be $\gamma=(74^{+20}_{-19})^{\rm o}$. This is one of the most precise single-measurement determinations of $\gamma$ to date.Comment: 22 pages, 9 figures; All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2015-020.htm

Study of WW boson production in association with beauty and charm

The associated production of a $W$ boson with a jet originating from either a light parton or heavy-flavor quark is studied in the forward region using proton-proton collisions. The analysis uses data corresponding to integrated luminosities of 1.0 and $2.0\,{\rm fb}^{-1}$ collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV, respectively. The $W$ bosons are reconstructed using the $W\to\mu\nu$ decay and muons with a transverse momentum, $p_{\rm T}$, larger than 20 GeV in the pseudorapidity range $2.0 20$ GeV and $2.2 < \eta < 4.2$. The sum of the muon and jet momenta must satisfy $p_{\rm T} > 20$ GeV. The fraction of $W+$jet events that originate from beauty and charm quarks is measured, along with the charge asymmetries of the $W\!+\!b$ and $W\!+\!c$ production cross-sections. The ratio of the $W+$jet to $Z+$jet production cross-sections is also measured using the $Z\to\mu\mu$ decay. All results are in agreement with Standard Model predictions

Measurement of the Bs0→J/ψηB_{s}^{0} \rightarrow J/\psi \eta lifetime

Using a data set corresponding to an integrated luminosity of $3 fb^{-1}$, collected by the LHCb experiment in $pp$ collisions at centre-of-mass energies of 7 and 8 TeV, the effective lifetime in the $B^0_s \rightarrow J/\psi \eta$ decay mode, $\tau_{\textrm{eff}}$, is measured to be $\tau_{\textrm{eff}} = 1.479 \pm 0.034~\textrm{(stat)} \pm 0.011 ~\textrm{(syst)}$ ps. Assuming $CP$ conservation, $\tau_{\textrm{eff}}$ corresponds to the lifetime of the light $B_s^0$ mass eigenstate. This is the first measurement of the effective lifetime in this decay mode.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://lhcbproject.web.cern.ch/lhcbproject/Publications/LHCbProjectPublic/LHCb-PAPER-2016-017.htm