Microstructure and electrical properties of (Ba0.6Sr0.4)0.85Bi0.1TiO3 ceramics prepared by single-step, liquid-phase, solid-state reactive sintering

(Ba0.6Sr0.4)0.85Bi0.1TiO3 ceramics have been obtained by single-step, liquid-phase, solid-state reactive sintering in the temperature range 1250–1350 °C using stoichiometric amounts of BaTiO3, SrTiO3 and Bi4Ti3O12. Their microstructure and electrical properties have been studied by X-Ray diffraction and fluorescence, scanning and transmission electron microscopy and impedance spectroscopy. The relative density, Dr, relative permittivity, ε′r, and dissipation factor, tan δ, at room temperature and the bulk and grain boundary resistivity, Rb and Rgb, and activation energies, Eba and Egba, are approximately independent of the sintering temperature with values around e.g. Dr ~97.5 %, ε′r ~1790, tan δ ~0.06 %, R500oCb ~26 kΩ cm, Egba ~1.03 eV, R500oCgb ~217 kΩ cm and Egba ~1.41 eV. By contrast, the temperature coefficient of capacitance, TCC, increases linearly from ~10 ppm oC−1 to ~21 ppm oC−1 on increasing sintering temperature. Comments on the influence of the sintering temperature on the chemical composition of the ceramics are made

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Synthesis of novel double hydrophilic block copoplymer architectures and their applications as crystal growth modifiers

L'objectif de cette étude est de démontrer l'influence de différentes architectures de copolymères à bloc doubles hydrophiles (DHBCs) sur le contrôle de la minéralisation de matériaux inorganiques en milieux aqueux. Une série de copolymères à bloc adaptés à l'étude en minéralisation, basés sur le PEO et le PAA, a tout d'abord été synthétisée (linéaires, triblocs et étoiles). Ensuite, l'étude systématique envisagée sur l'oxyde de zinc (ZnO) s'est avérée limitée pour des raisons expérimentales et seuls certains copolymères ont montré un incroyable contrôle sur ce système. Les conditions de précipitation du carbonate de calcium (CaCO3) étant mieux adaptées à nos additifs, une étude systématique de l'influence à la fois de l'architecture, de la longueur des blocs et de la masse molaire globale a été menée, prenant en compte l'analyse détaillée des caractéristiques intrinsèques des cristaux obtenus. La principale différence entre nos différentes architectures réside dans l'obtention d'effets binaires pour les linéaires et progressifs pour les étoiles, les triblocs servant de systèmes intermédiaires. De plus, cette étude nous a permis d'établir des modèles de mécanismes pour interpréter nous résultats ainsi que les conditions optimales d'utilisation de ce genre d'additif. Enfin, une étude préliminaire a été consacrée à l'étude de la stabilisation du carbonate de calcium sous sa forme amorphe par nos DHBCs. Les informations tirées de ces différentes études apportent quelques réponses quant au mécanisme global de biominéralisation.BORDEAUX1-BU Sciences-Talence (335222101) / SudocSudocFranceF

Nanosized amorphous calcium carbonate stabilized by poly(ethylene oxide)-b-poly(acrylic acid) block copolymers

Particles of amorphous calcium carbonate (ACC), formed in situ from calcium chloride by the slow release of carbon dioxide by alkaline hydrolysis of dimethyl carbonate in water, are stabilized against coalescence in the presence of very small amounts of double hydrophilic block copolymers (DHBCs) composed of poly(ethylene oxide) (PEO) and poly(acrylic acid) (PAA) blocks. Under optimized conditions, spherical particles of ACC with diameters less than 100 nm and narrow size distribution are obtained at a concentration of only 3 ppm of PEO-b-PAA as additive. Equivalent triblock or star DHBCs are compared to diblock copolymers. The results are interpreted assuming all interaction of the PAA blocks with the surface of the liquid droplets of the concentrated CaCO3 phase, formed by phase separation from the initially homogeneous reaction mixture. The adsorption layer of the block copolymer protects the liquid precursor of ACC from coalescence and/or coagulation

Le cinéma de Hou Hsiao-hsien

Né en 1947 à Canton, dans le Sud de la Chine, Hou Hsiao-hsien et sa famille, dans une période particulièrement trouble, se réfugient dès 1948 sur l'île de Taiwan. C'est là où il grandit, devient vite orphelin et cède à la délinquance avant de découvrir le cinéma. Dans les années 1980 il devient l'un des principaux cinéastes de la Nouvelle Vague taiwanaise. Ces années d'apprentissage, comptant déjà quelques grandes réussites (notamment Un temps pour vivre, un temps pour mourir) précédent la reconnaissance internationale. Le Lion d'or obtenu en 1989 pour La Cité des douleurs consacre en effet un cinéaste qui comptera parmi les plus importants des années 1990 et 2000. Entre films consacrés à l'histoire de Taiwan, films autobiographiques, films montrant la jeunesse contemporaine et expériences à l'étranger, les œuvres marquant profondément cette période et unanimement saluées par la critique sont nombreuses : Le Maître de marionnettes, Goodbye South, Goodbye, Millennium Mambo ou encore Café Lumière. En s'interrogeant plus particulièrement sur le traitement de l'espace, du temps et du son à l'œuvre dans l'ensemble de la filmographie du cinéaste taiwanais, les 14 textes constituant cet ouvrage collectif tentent de mettre en évidence les qualités formelles de l'un des plus grands cinéastes de notre temps

Doxorubicin alone versus doxorubicin with trabectedin followed by trabectedin alone as first-line therapy for metastatic or unresectable leiomyosarcoma (LMS-04): a randomised, multicentre, open-label phase 3 trial.

International audienc

Clinicopathological characterization of a real-world multicenter cohort of endometrioid ovarian carcinoma: Analysis of the French national ESME-Unicancer database

International audienc

L’année 2021 dans tous ses états : une synthèse digérée

International audience5548 Background: Ovarian cancer is the leading cause of death by gynecological cancer. Complete surgery remains one of the main prognostic factors. Laparoscopic exploration is mandatory to assess surgical resectability at diagnosis or after neoadjuvant chemotherapy. However, there is no clinical or biological marker that can correctly predict resectability and may be able to avoid a second laparoscopic exploration for initially unresectable diseases. Our aim was to assess circulating tumor DNA (ctDNA) value as a predictive non-invasive marker of evolution towards resectability for patients with epithelial ovarian cancer receiving first-line chemotherapy. Methods: We explored in this work one of the secondary objectives of the CIDOC study (NCT03302884). CIDOC is a multicenter prospective study aiming to explore ctDNA value as early marker of disease relapse after first-line treatment for epithelial ovarian cancer. Patients with mucinous histology or early stages not requiring chemotherapy are excluded. Plasma samples are collected at diagnosis, during neoadjuvant chemotherapy, and during follow-up. After DNA extraction, panel-based next generation sequencing is performed on both tumor samples and germline DNA, and somatic mutations of interest are selected for ctDNA monitoring. ctDNA analyses are conducted using droplet digital PCR (BioRad QX200) by measuring the variant allele fraction (VAF) of previously identified mutations. Results: This intermediary analysis has included 47 patients diagnosed between March 2017 and December 2019. Median age was 69 years old (48 – 84). Most of the patients had advanced disease (89.4% stage FIGO III or IV), serous histology (94.8%), and high grade tumor (92.3%). Most of the patients underwent complete interval cytoreductive surgery (76.3% vs 17.4% complete upfront surgery). Most of the tumors had TP53 mutations (85.1%), following by alterations involving DNA repair genes (38.3%). Median cell-free DNA concentration at baseline was 0.38 ng/µL (0 – 12.8). ctDNA was identified in 92.1% of patients at baseline with a median VAF of 1.84% (0 – 42.52%). ctDNA VAF was correlated to the peritoneal dissemination ( p= 0.039) assessed with the peritoneal cancer index. ctDNA clearance after preoperative chemotherapy tended to be correlated to achievement of complete interval surgery for patients receiving neoadjuvant chemotherapy ( p= 0.108). Conclusions: ctDNA may be a promising non-invasive marker to assess peritoneal cancer spreading and to predict surgical resectability after neoadjuvant chemotherapy. If confirmed in larger populations, this may enable to avoid additional surgical explorations for patients who remain ctDNA positive after chemotherapy. Clinical trial information: NCT03302884