Ice-Templating of Alumina Suspensions: Effect of Supercooling and Crystal Growth During the Initial Freezing Regime

International audienceWe investigate the ice-templating behavior of alumina suspensions by in situ X-ray radiography and tomography. We focus herein on the formation and structure of the transitional zone, occurring during the initial instants of freezing. For many applications, this zone is undesirable as the resulting porosity is heterogeneous in size, morphology, and orientation. We investigate the influence of the composition of alumina suspensions on the formation of the transitional zone. Alumina particles are dispersed by three different dispersants, in various quantities, or by hydrochloric acid. We show that the dimensions and the morphology of the transitional zone are determined by the growth of large dendritic ice-crystals growing in a supercooled state much faster than the cellular freezing front. When the freezing temperature decreases, the degree of supercooling increases. This results in an initial faster freezing front velocity and increase in the dimensions of the transitional zone. It is therefore possible to adjust the dimensions of the transitional zone by changing the composition of alumina suspensions. The counter-ion Na+ has the most dramatic effect on the freezing temperature of suspensions, yielding a predominance of cellular ice crystals instead of the usual lamellar crystals

A Randomized Prospective Non-Inferiority Trial of Sentinel Lymph Node Biopsy in Early Breast Cancer: Blue Dye Compared with Indocyanine Green Fluorescence Tracer.

[en] BACKGROUND: Indocyanine green (ICG) is a promising tracer for sentinel lymph node biopsy in early breast cancer. This randomized study was conducted to evaluate sentinel lymph node biopsy with ICG compared with blue dye as a tracer in woman with early breast cancer without any sign of lymph node invasion. METHODS: Between January 2019 and November 2020, 240 consecutive women with early breast cancer were enrolled and randomized to sentinel lymph node biopsy using ICG or blue dye. The primary endpoint was the sentinel lymph node detection rate in both arms. RESULTS: ICG was used in 121 patients and detected sentinel lymph nodes in all patients (detection rate, 100%; 95% CI: 96.9-100.0) while blue dye was used in 119 patients and detected sentinel lymph nodes in 116 patients (detection rate: 97.5%, 95% CI: 92.9-99.1). This analysis indicated the non-inferiority of ICG vs. blue dye tracer (90%CI: -1.9-6.9; p = 0.0009). CONCLUSION: ICG represents a new promising tracer to detect sentinel lymph nodes in early breast cancer with a detection rate similar to other conventional tracers, and is associated with easy learning and low cost. Our result suggest that this technique is a good alternative to avoid radioactive isotope manipulation

Sentinel lymph node mapping with patent blue dye in patients with breast cancer: a retrospective single institution study.

peer reviewed[en] BACKGROUND: Since the end of the last century, sentinel lymph node biopsy (SLNB) has replaced axillary lymph node dissection (ALND) as standard of care for axillary staging in early breast cancer in patients without any clinical sign of axillary lymph node infiltration. The worldwide most frequently used mapping method consists in the injection of radioactive technetium-99 isotope alone or in combination with blue dye. As a specific infrastructure and dedicated personnel are needed for the use of a radioactive tracer, the CHC in Liege (Belgium) decided to test the use of patent blue dye alone to detect sentinel lymph nodes in a large consecutive cohort of patients and compared the results with radioactive mapping methods and guidelines recommendations. METHODS: Patent blue dye was used in 456 consecutive patients with early breast cancer who underwent conservative breast cancer surgery or radical mastectomy between 1/1/2000 and 31/12/2007 in a community hospital (CHC Liège, Belgium). After SLNB, an ALND was performed in each patient. RESULTS: Sentinel lymph nodes were identified in 444 patients among the 456 patients evaluated by this mapping method during this time period, which represents a detection rate of 97.4%. Infiltrated lymph nodes were detected in 32.7% of patients (149/456) while in the 444 patients with sentinel lymph nodes identified and resected, 137 patients have at last one positive lymph node (30.9%). The false negative rate was 4.9% and the predictive negative value was 97.7% with the blue dye mapping method. CONCLUSIONS: In addition of the simplicity of the method and the large economic advantage, SNLB using blue dye alone showed a quite acceptable performance in our retrospective analysis concerning its ability to find the SLN as well as its reliability to remove the good ones

Genome-wide association mapping for root cone angle in rice

Background: Plant root systems play a major role in anchoring and in water and nutrient uptake from the soil. The root cone angle is an important parameter of the root system architecture because, combined with root depth, it helps to determine the volume of soil explored by the plant. Two genes, DRO1 and SOR1, and several QTLs for root cone angle have been discovered in the last 5 years. Results: To find other QTLs linked to root cone angle, a genome-wide association mapping study was conducted on two panels of 162 indica and 169 japonica rice accessions genotyped with two sets of SNP markers (genotyping-by-sequencing set with approximately 16,000 markers and high-density-rice-array set with approximately 300,000 markers). The root cone angle of all accessions was measured using a screen protractor on images taken after 1 month of plant growth in the Rhizoscope phenotyping system. The distribution of the root cone angle in the indica panel was Gaussian, but several accessions of the japonica panel (all the bulus from Indonesia and three temperate japonicas from Nepal or India) appeared as outliers with a very wide root cone angle. The data were submitted to association mapping using a mixed model with control of structure and kinship. A total of 15 QTLs for the indica panel and 40 QTLs for the japonica panel were detected. Genes underlying these QTLs (+/−50 kb from the significant markers) were analyzed. We focused our analysis on auxin-related genes, kinases, and genes involved in root developmental processes and identified 8 particularly interesting genes. Conclusions: The present study identifies new sources of wide root cone angle in rice, proposes ways to bypass some drawbacks of association mapping to further understand the genetics of the trait and identifies candidate genes deserving further investigation. (Résumé d'auteur

Oxidative Stress Status in COVID-19 Patients Hospitalized in Intensive Care Unit for Severe Pneumonia. A Pilot Study

peer reviewe

Death and the Societies of Late Antiquity

Ce volume bilingue, comprenant un ensemble de 28 contributions disponibles en français et en anglais (dans leur version longue ou abrégée), propose d’établir un état des lieux des réflexions, recherches et études conduites sur le fait funéraire à l’époque tardo-antique au sein des provinces de l’Empire romain et sur leurs régions limitrophes, afin d’ouvrir de nouvelles perspectives sur ses évolutions possibles. Au cours des trois dernières décennies, les transformations considérables des méthodologies déployées sur le terrain et en laboratoire ont permis un renouveau des questionnements sur les populations et les pratiques funéraires de l’Antiquité tardive, période marquée par de multiples changements politiques, sociaux, démographiques et culturels. L’apparition de ce qui a été initialement désigné comme une « Anthropologie de terrain », qui fut le début de la démarche archéothanatologique, puis le récent développement d’approches collaboratives entre des domaines scientifiques divers (archéothanatologie, biochimie et géochimie, génétique, histoire, épigraphie par exemple) ont été décisives pour le renouvellement des problématiques d’étude : révision d’anciens concepts comme apparition d’axes d’analyse inédits. Les recherches rassemblées dans cet ouvrage sont articulées autour de quatre grands thèmes : l’évolution des pratiques funéraires dans le temps, l’identité sociale dans la mort, les ensembles funéraires en transformation (organisation et topographie) et les territoires de l’empire (du cœur aux marges). Ces études proposent un réexamen et une révision des données, tant anthropologiques qu’archéologiques ou historiques sur l’Antiquité tardive, et révèlent, à cet égard, une mosaïque de paysages politiques, sociaux et culturels singulièrement riches et complexes. Elles accroissent nos connaissances sur le traitement des défunts, l’emplacement des aires funéraires ou encore la structure des sépultures, en révélant une diversité de pratiques, et permettent au final de relancer la réflexion sur la manière dont les sociétés tardo-antiques envisagent la mort et sur les éléments permettant d’identifier et de définir la diversité des groupes qui les composent. Elles démontrent ce faisant que nous pouvons véritablement appréhender les structures culturelles et sociales des communautés anciennes et leurs potentielles transformations, à partir de l’étude des pratiques funéraires.This bilingual volume proposes to draw up an assessment of the recent research conducted on funerary behavior during Late Antiquity in the provinces of the Roman Empire and on their borders, in order to open new perspectives on its possible developments. The considerable transformations of the methodologies have raised the need for a renewal of the questions on the funerary practices during Late Antiquity, a period marked by multiple political, social, demographic and cultural changes. The emergence field anthropology, which was the beginning of archaeothanatology, and then the recent development of collaborative approaches between various scientific fields (archaeothanatology, biochemistry and geochemistry, genetics, history, epigraphy, for example), have been decisive. The research collected in this book is structured around four main themes: Evolution of funerary practices over time; Social identity through death; Changing burial grounds (organisation and topography); Territories of the Empire (from the heart to the margins). These studies propose a review and a revision of the data, both anthropological and archaeological or historical on Late Antiquity, and reveal a mosaic of political, social, and cultural landscapes singularly rich and complex. In doing so, they demonstrate that we can truly understand the cultural and social structures of ancient communities and their potential transformations, based on the study of funerary practices