Riesgo quirúrgico tras resección pulmonar anatómica en cirugía torácica. Modelo predictivo a partir de una base de datos nacional multicéntrica

Introduction: the aim of this study was to develop a surgical risk prediction model in patients undergoing anatomic lung resections from the registry of the Spanish Video-Assisted Thoracic Surgery Group (GEVATS). Methods: data were collected from 3,533 patients undergoing anatomic lung resection for any diagnosis between December 20, 2016 and March 20, 2018. We defined a combined outcome variable: death or Clavien Dindo grade IV complication at 90 days after surgery. Univariate and multivariate analyses were performed by logistic regression. Internal validation of the model was performed using resampling techniques. Results: the incidence of the outcome variable was 4.29% (95% CI 3.6-4.9). The variables remaining in the final logistic model were: age, sex, previous lung cancer resection, dyspnea (mMRC), right pneumonectomy, and ppo DLCO. The performance parameters of the model adjusted by resampling were: C-statistic 0.712 (95% CI 0.648-0.750), Brier score 0.042 and bootstrap shrinkage 0.854. Conclusions: the risk prediction model obtained from the GEVATS database is a simple, valid, and reliable model that is a useful tool for establishing the risk of a patient undergoing anatomic lung resection

Analyse in situ d’une batterie à flux redox organique par résonance magnétique et fabrication additive

This thesis project aims at studying the operation of electrochemical cells using integrated nuclear magnetic resonance systems combined with additive manufacturing technologies. Recent advances allow the development of a real time monitoring tool for the identification of the different molecular species and migrations generated during the operation of an organic redox flow battery. To this end, several 3D printed minibattery prototypes have been designed by optimizing parameters such as size, geometry, the volume of the compartments and the material of the electrodes. A wide bore vertical magnet allows for imaging of the batteries during operation as well as obtaining real-time localized spectra over the region corresponding to the molecules of interest during cycling. The main challenge to make this system work was to overcome operational constraints such as size limitations of the volumes of interest, radio frequency interference or magnetic field inhomogeneities.On the other hand, fluidic devices for NMR microdetection connected on a standard microimaging NMR probe base were designed with different radio frequency coil geometries. The 3D printed insert is coupled to a bubble pump where an inert carrier gas establishes a closed-loop fluid flow circuit. This high-sensitivity system allows in situand operando monitoring of liquid electrolytes by studying the displacement mechanisms and structure of molecular species (high-resolution homonuclear and heteronuclear spatially localized 1D and 2D spectra) during the redox reaction.Le présent projet de thèse vise à étudier le fonctionnement de cellules électrochimiques mettant à profit des systèmes intégrés de résonance magnétique nucléaire combinés avec des technologies de fabrication additive. Les avancées récentes permettent le développement d'un outil de suivi en temps réel pour l'identification des différentes espèces moléculaires et les migrations générées lors du fonctionnement d'une batterie à flux redox organique. À cet effet, plusieurs prototypes de mini-batteries imprimés en 3D ont été conçus en optimisant des paramètres tels que la taille, la géométrie, le volume des compartiments et le matériau des électrodes. Un aimant vertical de grande cavité permet l'obtention d'images des batteries en fonctionnement ainsi que l'obtention en temps réel de spectres localisés sur la région correspondant aux molécules d'intérêt au cours du cyclage. Le principal défi pour faire fonctionner ce système a consisté à surmonter les contraintes opérationnelles telles que les limitations de taille des volumes d'intérêt, les interférences radiofréquences ou les inhomogénéités de champ magnétique.D'autre part, des dispositifs fluidiques pour la micro-détection RMN connectés sur une base de sonde RMN de micro-imagerie standard ont été conçus avec différentes géométries de bobine radiofréquence. L'insert imprimé en 3D est couplé à une pompe à bulle où un gaz porteur inerte établit un circuit d'écoulement de fluide à boucle fermée. Ce système à haute sensibilité permet le suivi in situ et operando d'électrolytes liquides par l'étude des mécanismes de déplacement et de la structure des espèces moléculaires (spectres 1D et 2D à haute résolution homonucléaires et hétéronucléaires localisés dans l'espace) pendant la réaction redox

Analyse in situ d’une batterie à flux redox organique par résonance magnétique et fabrication additive

This thesis project aims at studying the operation of electrochemical cells using integrated nuclear magnetic resonance systems combined with additive manufacturing technologies. Recent advances allow the development of a real time monitoring tool for the identification of the different molecular species and migrations generated during the operation of an organic redox flow battery. To this end, several 3D printed minibattery prototypes have been designed by optimizing parameters such as size, geometry, the volume of the compartments and the material of the electrodes. A wide bore vertical magnet allows for imaging of the batteries during operation as well as obtaining real-time localized spectra over the region corresponding to the molecules of interest during cycling. The main challenge to make this system work was to overcome operational constraints such as size limitations of the volumes of interest, radio frequency interference or magnetic field inhomogeneities.On the other hand, fluidic devices for NMR microdetection connected on a standard microimaging NMR probe base were designed with different radio frequency coil geometries. The 3D printed insert is coupled to a bubble pump where an inert carrier gas establishes a closed-loop fluid flow circuit. This high-sensitivity system allows in situand operando monitoring of liquid electrolytes by studying the displacement mechanisms and structure of molecular species (high-resolution homonuclear and heteronuclear spatially localized 1D and 2D spectra) during the redox reaction.Le présent projet de thèse vise à étudier le fonctionnement de cellules électrochimiques mettant à profit des systèmes intégrés de résonance magnétique nucléaire combinés avec des technologies de fabrication additive. Les avancées récentes permettent le développement d'un outil de suivi en temps réel pour l'identification des différentes espèces moléculaires et les migrations générées lors du fonctionnement d'une batterie à flux redox organique. À cet effet, plusieurs prototypes de mini-batteries imprimés en 3D ont été conçus en optimisant des paramètres tels que la taille, la géométrie, le volume des compartiments et le matériau des électrodes. Un aimant vertical de grande cavité permet l'obtention d'images des batteries en fonctionnement ainsi que l'obtention en temps réel de spectres localisés sur la région correspondant aux molécules d'intérêt au cours du cyclage. Le principal défi pour faire fonctionner ce système a consisté à surmonter les contraintes opérationnelles telles que les limitations de taille des volumes d'intérêt, les interférences radiofréquences ou les inhomogénéités de champ magnétique.D'autre part, des dispositifs fluidiques pour la micro-détection RMN connectés sur une base de sonde RMN de micro-imagerie standard ont été conçus avec différentes géométries de bobine radiofréquence. L'insert imprimé en 3D est couplé à une pompe à bulle où un gaz porteur inerte établit un circuit d'écoulement de fluide à boucle fermée. Ce système à haute sensibilité permet le suivi in situ et operando d'électrolytes liquides par l'étude des mécanismes de déplacement et de la structure des espèces moléculaires (spectres 1D et 2D à haute résolution homonucléaires et hétéronucléaires localisés dans l'espace) pendant la réaction redox

A 3D-printed device for in situ monitoring of an organic redox-flow battery via NMR/MRI

International audienceA mini organic redox-flow battery pluggable on the basis of a high-resolution NMR probehead has been conceived and built mainly by 3D printing. This device allows the realization of all modern spectroscopy experiments as well as imaging experiments. It has been tested for the real-time monitoring of redox cycling of 9,10-Anthraquinone-2,7-disulfonic acid disodium salt (2,7-AQDS) in acidic conditions, which has revealed the preponderant role of dimerization in the processes of oxidation and reduction. Determination of the thermodynamic properties of homo-and heterodimer formation through quantum chemical, multilevel modeling workflows confirm our hypotheses about the molecular processes occurring during charge and discharge

BIOSORCIÓN DEL COBRE (II) POR EL ALGA MARINA PRETRATADA LESSONIA TRABECULADA

The conditions of maximum biosorption of Copper (ll) have been determined on dry algae Lessonia trabeculata. The optimal biosorption has been obtained at pH = 4,0, initial concentration = 500mg/l, size of particle of biosorbent (250 < P < 500 um). The adsorption isotherms fitted well with Langmuir and Freundlich models. The maximum adsorption was determined to be qm= 90,54 mg/gSe han determinado las condiciones de máxima biosorción del Cobre (ll) sobre alga seca Lessonia trabeculata. La óptima biosorción se obtuvo a pH= 4.0, concentración inicial = 500mg/l, tamaño de partícula del biosorbente (250 < P < 500 um). Los resultados experimentales fueron tratados con los modelos matemáticos de Freundlich y Langmuir. La máxima capacidad de adsorción fue qm = 90,54 mg/g

Cellulose nanofibers-sepiolite biohybrid materials

Oral presentation given at the XVI International Clay Conference, held in Granada (Spain) on July 17-21, 2017.Bionanocomposites are a type of nanostructured biohybrid materials resulting from the assembly of naturally occurring polymers and inorganic solids with particle size in the nanometer scale [1], as for instance diverse clay minerals with layered or fibrous morphology [2,3]. Amongst biopolymers, there is a special interest in the use of polysaccharides for the preparation of bionanocomposites due to their abundancy in nature and their renewable and biodegradable character. In the recent years, many works are focusing on the use of cellulose, the most abundant polysaccharide on Earth, to develop new hybrid materials involving clay minerals [4-7]. Cellulose chains consisting of β(1→4) linked D-glucose units are arranged in crystalline and amorphous regions forming elementary fibrils, which are in turn assembled forming the cellulose fibers present in the cell wall of plants [8]. In this context, the current work explores the development of biohybrids based on the assembly of cellulose nanofibers (CNF) to the fibrous clay sepiolite. For this purpose, Pangel® S9, sepiolite from Vallecas-Vicálvaro of rheological grade commercialized by Tolsa SA, was used together with CNF (dimensions around 0.5-2 μm in length and 4-20 nm in diameter), which was prepared following a reported procedure [9] and gently provided by Prof. P. Mutjé (LEPAMAP group, Univ. of Girona, Spain). Aqueous suspensions of CNF and sepiolite were combined by means of shear force and ultrasounds energy in order to produce homogenous and stable gels, which can be dried by solvent casting or vacuum filtration leading to self-standing films [7]. The sonication treatment seems to be compulsory in order to obtain uniform films with a considerable degree of transparency. The characterization of these materials reveals the good interaction between both types of fibers of biological and inorganic nature. The decrease in intensity of the IR vibration band at 3720 cm-1, related to the O-H stretching vibration of silanol groups in sepiolite, suggests a perturbation due to their hydrogen bonding interaction with hydroxyl groups in CNF. Accordingly, XPS results show a large perturbation in the C1s signal from CNF as a consequence of its interaction with sepiolite. Tensile modulus values of hybrid films show slightly higher values than those of the individual components, reaching a maximum value of 3.4 GPa for the material containing 20% sepiolite. The thermal stability was also improved as the sepiolite content increased, showing a shift in the thermal decomposition temperature towards higher values. The degree of hydrophobicity can be also controlled with the sepiolite content, and thus, water adsorption was reduced in hybrid films containing a small percentage of inorganic fibers in comparison to pristine CNF. The possibility of incorporating other nanoparticles allows the preparation of multifunctional materials [10]. For instance, multi-walled carbon nanotubes (MWCNTs) can be included in the CNF-sepiolite hybrids in order to provide them with electrical conductivity, allowing their application as active phase in sensor devices.MINECO (Spain), projects MAT2012-31759 & MAT2015-71117-R, and PhD fellowship BES-2013-064677 (MMGC)

Atomic Layer Deposition of a Nanometer-Thick Li₃PO₄ Protective Layer on LiNi_0.5Mn_1.5O₄ Films: Dream or Reality for Long-Term Cycling?

International audienceLiNi0.5Mn1.5O4 (LNMO) is a promising 5V-class electrode for Li-ion batteries but suffers from manganese dissolution and electrolyte decomposition owing to the high working potential. An attractive solution to stabilize the surface chemistry consists in mastering the interface between the LNMO electrode and the liquid electrolyte with a surface protective layer made from the powerful surface deposition method. Here, we show that a 7400 nm thick sputtered LNMO film coated with a nanometer-thick lithium-ion-conductive Li3PO4 layer was deposited by the atomic layer deposition method. We demonstrate that this “material model system” can deliver a remarkable surface capacity (∼0.4 mAh cm–2 at 1C) and exhibits improved cycling lifetime (×650%) compared to the nonprotected electrode. Nevertheless, we observe that mechanical failure occurs within the LNMO and Li3PO4 films when long-term cycling is performed. This in-depth study gives new insights regarding the mechanical degradation of LNMO electrodes upon charge/discharge cycling and reveals for the first time that the surface protective layer made from the ALD method is not sufficient for long-term stability applications

Graphene synthesis on SiO2 using pulsed laser deposition with bilayer predominance

International audienceHere we report the low-defect synthesis of bilayer graphene film on SiO 2 with a nickel catalyst using pulsed laser deposition combined with rapid thermal annealing. A parametric study was performed with various initial amorphous carbon (a-C) film thicknesses and annealing temperatures and a fixed nickel catalyst film thickness. Raman spectra and mapping over large areas of up to 100 × 100 μm² were used to investigate the structure and the defects of graphene films. Optimal conditions for graphene growth were an initial a-C film thickness of 2 nm and an annealing temperature of 900°C. Results showed that 76% of the optimized film contained graphene bilayers, and 18% of the optimized film contained graphene monolayers. A transmittance of 87% at 550 nm is observed without any transfer process from the SiO 2 substrate. This paper presents experimental guidelines for optimal synthesis conditions to control graphene growth by pulsed laser deposition

Atomic Layer Deposition of a Nanometer-Thick Li₃PO₄ Protective Layer on LiNi_0.5Mn_1.5O₄ Films: Dream or Reality for Long-Term Cycling?

International audienceLiNi0.5Mn1.5O4 (LNMO) is a promising 5V-class electrode for Li-ion batteries but suffers from manganese dissolution and electrolyte decomposition owing to the high working potential. An attractive solution to stabilize the surface chemistry consists in mastering the interface between the LNMO electrode and the liquid electrolyte with a surface protective layer made from the powerful surface deposition method. Here, we show that a 7400 nm thick sputtered LNMO film coated with a nanometer-thick lithium-ion-conductive Li3PO4 layer was deposited by the atomic layer deposition method. We demonstrate that this “material model system” can deliver a remarkable surface capacity (∼0.4 mAh cm–2 at 1C) and exhibits improved cycling lifetime (×650%) compared to the nonprotected electrode. Nevertheless, we observe that mechanical failure occurs within the LNMO and Li3PO4 films when long-term cycling is performed. This in-depth study gives new insights regarding the mechanical degradation of LNMO electrodes upon charge/discharge cycling and reveals for the first time that the surface protective layer made from the ALD method is not sufficient for long-term stability applications