Search results for "Lag"

Les emballages biodégradables : durée de vie du produit ou durée de vie de l’emballage ? Exemple du PLA

2019

National audience; Parmi les matériaux d’emballages issus de ressources renouvelables, il est important de bien différencier ceux qui sont biosourcés mais non biodégradables (souvent analogues aux matériaux conventionnels pétrosourcés) de ceux qui sont à la fois biosourcés et biodégradables. Pour ces derniers, la question de leur stabilité au contact des produits alimentaires s’avère alors cruciale. Le cas du poly(lactide), ou PLA, est détaillé ici, en prenant en compte non seulement sa stabilité chimique, mais aussi sa stabilité physique. Se pose alors la question de la durée de vie de l’emballage en parallèle de celle de la durée de vie de l’aliment emballé.

Disruption of apical-basal polarity of human embryonic stem cells enhances hematoendothelial differentiation

2007

Abstract During murine development, the formation of tight junctions and acquisition of polarity are associated with allocation of the blastomeres on the outer surface of the embryo to the trophoblast lineage, whereas the absence of polarization directs cells to the inner cell mass. Here, we report the results of ultrastructural analyses that suggest a similar link between polarization and cell fate in human embryos. In contrast, the five human embryonic stem cell (hESC) lines displayed apical-basal, epithelial-type polarity with electron-dense tight junctions, apical microvilli, and asymmetric distribution of organelles. Consistent with these findings, molecules that are components of tigh…

Characterization of glycoconjugate expression during development of Meckel's cartilage in the rat

1995

The staining patterns of 24 biotinylated lectins were analyzed in serial sections of the mandible of 13- to 21-day-old rat embryos by means of the avidin-biotin-peroxidase method. A ubiquitous distribution of binding sites was demonstrated after incubation with Con A (Canavalia ensiformis), DSL (Datura stramonium; except bone matrix), and WGA (Triticum vulgare). ECL (Erythrina cristagalli), GSL I (Griffonia simplicifolia), SJA (Saphora japonica), VVL (Vicia villosa), DBA (Dolichus biflorus), UEA I (Ulex europeus), and LTA (Lotus tetragonobolus) were constantly negative. In early stages of development, GSL II (Griffonia simplicifolia II) was a selective marker of prechondral blastema. In con…

Isolation of fibroblasts for coating of meshes for reconstructive surgery: differences between mesh types.

2009

Aims: An extensive colonization of surgical meshes with autologous fibroblasts may reduce complications. Therefore, we aimed to establish a technique that allows isolation and propagation of fibroblasts from vaginal biopsies. Using these cells we tested the applicability of several clinically applied meshes for fibroblast coating. Materials & methods: Fibroblasts were isolated from vaginal tissue after digestion with collagenase. Characterization was performed by immunostaining for cytokeratin 5, 6 and 14, smooth muscle actin and vimentin. A semiquantitative technique was applied to determine the degree of mesh coating 5 h and 5 weeks after seeding of fibroblasts. Seven meshes of diffe…

The cross-lagged associations between classroom interactions and children’s achievement behaviors

2014

This study examined the cross-lagged associations between the quality of classroom interactions and children’s behaviors in achievement situations. The achievement behaviors in challenging test situations of 166 Finnish children from 70 classrooms were rated by trained testers in grades 1 and 2. The quality of classroom interactions in terms of emotional support, classroom organization, and instructional support were observed in 25 classrooms (out of 70) in grades 1 and 2. The results of multilevel modeling showed that classroom teachers’ low emotional support predicted children’s subsequent high passive avoidance, whereas high classroom organization and instructional support predicted chil…

Calpains promote α2β1 integrin turnover in nonrecycling integrin pathway

2012

A novel virus- and integrin clustering–specific pathway diverts integrin from its normal endo/exocytic traffic to a nonrecycling degradative endosomal route. Clustering of α2β1 integrin causes redistribution of the integrin to perinuclear endosomes, leading to enhanced integrin turnover promoted by calpains.

Effect of phosphonate-functionalised nanoparticles on human mesenchymal stem cells and osteoclasts

2011

Nanotechnologies for Active and Intelligent Food Packaging: Opportunities and Risks

2017

This chapter focuses on providing a comprehensive review on the current development of nanotechnology in the field of active and intelligent packaging for food. Systems devoted to intelligent food packaging require easy-to-read, cheap, robust, and safe systems that are able to provide on time information. Food and Drug Administration (FDA) considers that evaluations of safety, effectiveness, public health impact, or regulatory status of nanotechnology products should consider any unique properties and behaviors that the application of nanotechnology may impart. The lack of regulatory support providing standardized risk assessments of engineered nanomaterials (ENM) through integration of haz…

TERRE project: interplay between unsaturated soil mechanics and low-carbon geotechnical engineering

2020

The geotechnical construction industry is a major component of the overall construction sector and is strategically important in infrastructure development (transportation, flood and landslide protection, building foundations, waste disposal). Although industry and research in the overall construction sector have been investing significantly in recent years to produce innovative low-carbon technologies, little innovation has been created in geotechnical construction industry, which is lagging behind other construction industry sectors. This paper discusses the interplay between low-carbon geotechnical engineering and unsaturated soil mechanics based on the research carried out within the pr…

A study of noise transmission through cylindrical shell using modal truncation approach

2011

International audience; The study of the vibroacoustic behaviour of cylindrical structure like aircraft fuselage requires the establishment of very large models, and the numerical results which can be obtained are often difficult to interpret. On the other hand, the study of simple structures such as cylindrical shells is useful to validate the criteria and tools that can be used to simplify the models of complex structures. The presented study concerns the sound transmission through a cylindrical shell coupled to a cavity and subjected to an incident acoustic wave. Noise reduction is obtained and validated by a numerical method which uses structural and acoustical modes. A criterion for se…