Reabilitação cognitiva em idosos institucionalizados: um estudo piloto

Este estudo descreve os efeitos da intervenção de terapia ocupacional no desempenho cognitivo, e analisa a influência deste desempenho na capacidade funcional de idosos institucionalizados. Trata-se de um estudo clínico randomizado, descritivo, longitudinal, realizado em uma instituição pública de longa permanência de idosos. Os 12 idosos que participaram do estudo foram divididos em dois grupos: experimental e controle. Para obtenção dos dados, foram utilizados: um questionário com dados sociodemográficos; o Mini-Exame do Estado Mental, o Teste de Fluência Verbal e o Teste do Relógio, para avaliação do desempenho cognitivo; e a Escala de Katz da Atividade de Vida Diária e o Questionário de Atividades Funcionais de Pfeffer, para avaliação da capacidade funcional. Os idosos do grupo experimental foram submetidos a uma intervenção com 23 sessões de reabilitação cognitiva. O grupo que recebeu a intervenção apresentou resultados estatisticamente significativos no desempenho cognitivo, mas não houve resultados estatisticamente significativos no desempenho da capacidade funcional quando comparados com o grupo controle. Conclui-se que a intervenção de terapia ocupacional teve efeitos significativos no desempenho cognitivo de idosos institucionalizados e que, provavelmente, o desempenho na capacidade funcional não foi tão significativo, por se tratar de idosos que, em sua maioria, apresentam limitação motora e dependência instalada

New genetic loci link adipose and insulin biology to body fat distribution.

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms

Genetic associations at 53 loci highlight cell types and biological pathways relevant for kidney function.

Reduced glomerular filtration rate defines chronic kidney disease and is associated with cardiovascular and all-cause mortality. We conducted a meta-analysis of genome-wide association studies for estimated glomerular filtration rate (eGFR), combining data across 133,413 individuals with replication in up to 42,166 individuals. We identify 24 new and confirm 29 previously identified loci. Of these 53 loci, 19 associate with eGFR among individuals with diabetes. Using bioinformatics, we show that identified genes at eGFR loci are enriched for expression in kidney tissues and in pathways relevant for kidney development and transmembrane transporter activity, kidney structure, and regulation of glucose metabolism. Chromatin state mapping and DNase I hypersensitivity analyses across adult tissues demonstrate preferential mapping of associated variants to regulatory regions in kidney but not extra-renal tissues. These findings suggest that genetic determinants of eGFR are mediated largely through direct effects within the kidney and highlight important cell types and biological pathways

Epitaxie de semiconducteurs II-VI : ZnTe/ZnSe et CdTe:Se. <br />Etude du confinement électronique de type-II et du dopage isoélectronique

This work is based on the growth, by molecular beam epitaxy, of semiconductor heterostructures in which tellurium and selenium coexist. The goals are to develop optimized growth conditions and to study the specific physical properties due to this coexistence. More specifically, we worked on ZnTe/ZnSe type-II quantum wells and quantum dots, and on isoelectronic centers CdTe: Se.For ZnTe highly strained on ZnSe we observed a Stranski-Krastanov like relaxation and surface reorganization, but with large scale undulations. Nevertheless we managed to obtained nanometer scale islands thanks to a surface treatment based on amorphous tellurium deposition and sublimation. Then we were faced with difficulties regarding islands capping to form quantum dots. Under usual ZnSe growth conditions, the ZnTe islands are fully flattened and disappear. We propose new growth conditions to preserve the islands and obtain 0D confinement. We observe that the nanostructures we developed are never based on pure ZnTe in ZnSe but on ordered alloy ZnSeTe which forms spontaneously.We studied in details the photoluminescence and time resolved photoluminescence properties of thin ZnTe/ZnSe quantum wells and of ZnTe/ZnSe quantum dot planes. The huge difference observed between those two kinds of samples is fully explained by a model based on electrostatic and statistical peculiarity of confinement in the case of type-II band alignment.The last part of this manuscript is dedicated to the delta-doping of CdTe with selenium. We succeeded in isolating a single selenium based localization center and study the anti-bunching of photons emitted by such centers, proving that they behave as single photons emitters.Ce travail repose sur le développement de la croissance, par épitaxie par jets moléculaires, d'hétérostructures présentant une alliance de deux familles de matériaux semi-conducteurs: les tellurures et les séléniures. Il tend à montrer l'originalité des propriétés physique spécifiques de cette association en développant deux cas: les puits et les boîtes quantiques de type-II ZnTe/ZnSe et les centres isoélectroniques CdTe:Se. Pour ZnTe fortement contraint sur ZnSe, une transition morphologique de type Stranski-Krastanow non-standard a été observée. La formation d'îlots nanométriques a pu être obtenue grâce à un traitement de surface à base de Te amorphe. Lors de leur encapsulation, nous avons été confrontés à une disparition totale de ces îlots. Nous proposons de nouvelles conditions de croissance qui limitent les phénomènes de ségrégation, ou d'échange Se/Te, et préservent en partie les îlots. Cependant les nanostructures obtenues ne contiennent pas ZnTe sous forme binaire pure mais sous forme d'alliage ordonné ZnSeTe. Les propriétés de photoluminescence d'un plan de boîtes quantiques et celles d'un puits quantique ZnTe/ZnSe sont analysées et comparées. Nous proposons un modèle capable de décrire parfaitement les différents résultats optiques spécifiques d'un système où l'alignement de bande est de type-II. Ce modèle est basé sur des arguments statistiques et électrostatiques.La dernière partie traite de l'insertion d'atomes de sélénium dans CdTe sous forme d'un dopage planaire. Des centres isoélectroniques sélénium ont pu être isolés. Une mesure du dégroupement des photons émis montre que ces objets individuels se comportent comme des émetteurs de photons uniques

Epitaxie de semiconducteurs II-VI:ZnTe/ZnSe et CdTe:Se (étude du confinement électronique de type-II et du dopage isoélectronique)

Ce travail repose sur le développement de la croissance, par épitaxie par jets moléculaires, d'hétérostructures présentant une alliance de deux familles de matériaux semi-conducteurs: les tellurures et les séléniures. Il tend à montrer l'originalité des propriétés physique spécifiques de cette association en développant deux cas: les puits et les boîtes quantiques de type-II ZnTe/ZnSe et les centres isoélectroniques CdTe:Se. Pour ZnTe fortement contraint sur ZnSe, une transition morphologique de type Stranski-Krastanow non-standard a été observée. La formation d'îlots nanométriques a pu être obtenue grâce à un traitement de surface à base de Te amorphe. Lors de leur encapsulation, nous avons été confrontés à une disparition totale de ces îlots. Nous proposons de nouvelles conditions de croissance qui limitent les phénomènes de ségrégation, ou d'échange Se/Te, et préservent en partie les îlots. Cependant les nanostructures obtenues ne contiennent pas ZnTe sous forme binaire pure mais sous forme d'alliage ordonné ZnSeTe. Les propriétés de photoluminescence d'un plan de boîtes quantiques et celles d'un puits quantique ZnTe/ZnSe sont analysées et comparées. Nous proposons un modèle capable de décrire parfaitement les différents résultats optiques spécifiques d'un système où l'alignement de bande est de type-II. Ce modèle est basé sur des arguments statistiques et électrostatiques. La dernière partie traite de l'insertion d'atomes de sélénium dans CdTe sous forme d'un dopage planaire. Des centres isoélectroniques sélénium ont pu être isolés. Une mesure du dégroupement des photons émis montre que ces objets individuels se comportent comme des émetteurs de photons uniques.This work is based on the growth, by molecular beam epitaxy, of semiconductor heterostructures in which tellurium and selenium coexist. The goals are to develop optimized growth conditions and to study the specific physical properties due to this coexistence. More specifically, we worked on ZnTe/ZnSe type-II quantum wells and quantum dots, and on isoelectronic centers CdTe: Se. For ZnTe highly strained on ZnSe we observed a Stranski-Krastanov like relaxation and surface reorganization, but with large scale undulations. Nevertheless we managed to obtained nanometer scale islands thanks to a surface treatment based on amorphous tellurium deposition and sublimation. Then we were faced with difficulties regarding islands capping to form quantum dots. Under usual ZnSe growth conditions, the ZnTe islands are fully flattened and disappear. We propose new growth conditions to preserve the islands and obtain 0D confinement. We observe that the nanostructures we developed are never based on pure ZnTe in ZnSe but on ordered alloy ZnSeTe which forms spontaneously. We studied in details the photoluminescence and time resolved photoluminescence properties of thin ZnTe/ZnSe quantum wells and of ZnTe/ZnSe quantum dot planes. The huge difference observed between those two kinds of samples is fully explained by a model based on electrostatic and statistical peculiarity of confinement in the case of type-II band alignment. The last part of this manuscript is dedicated to the delta-doping of CdTe with selenium. We succeeded in isolating a single selenium based localization center and study the anti-bunching of photons emitted by such centers, proving that they behave as single photons emitters.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

A review on the current research on graphene-based aerogels and their applications

Graphene aerogels (GAs) are amongst the lightest materials in the world. They attracted increasing interest in academia and industry because of their exceptional and unique properties, like high mechanical strength, electrical conductivity, thermal resistance, and adsorption capacity. In this review, we describe advances in research and development of a variety of methods that lead to the synthesis of graphene-based aerogels. First, the main common methods for producing GAs are examined, such as chemical reduction, hydrothermal reduction, crosslinking, polymerization methods, and template-directed reduction. Furthermore, the advancement of the 3D printing of GAs is presented. These methods resulted in GAs with porous hierarchical textures, low densities, and improved electrical conductivities, robust mechanical properties, better stability, and excellent adsorption potential. Then, the promising potential applications of GAs in the domains of energy storage, energy conversion, and environmental protection are evaluated. Finally, the prospects and challenges associated with the manufacturing of GAs are discussed

Type-II excitons in ZnTe/ZnSe quantum dots

International audienc

Molecular beam epitaxy growth of ZnTe/ZnSe Type-II quantum dots

International audienc

Type-II ZnTe/ZnSe quantum dots and quantum wells

International audienc

Se-Se isoelectronic centers in high purity CdTe

International audienc