The MoS2 Nanotubes with Defect-Controlled Electric Properties

We describe a two-step synthesis of pure multiwall MoS2 nanotubes with a high degree of homogeneity in size. The Mo6S4I6 nanowires grown directly from elements under temperature gradient conditions in hedgehog-like assemblies were used as precursor material. Transformation in argon-H2S/H2 mixture leads to the MoS2 nanotubes still grouped in hedgehog-like morphology. The described method enables a large-scale production of MoS2 nanotubes and their size control. X-ray diffraction, optical absorption and Raman spectroscopy, scanning electron microscopy with wave dispersive analysis, and transmission electron microscopy were used to characterize the starting Mo6S4I6 nanowires and the MoS2 nanotubes. The unit cell parameters of the Mo6S4I6 phase are proposed. Blue shift in optical absorbance and metallic behavior of MoS2 nanotubes in two-probe measurement are explained by a high defect concentration

MBaaS-based Authentication service for handicraft products traceability system

International audienceCounterfeiting is copying a product without having the right. It affects all manufacturing sectors, mainly, the craft sector. Authentication is a solution to prevent handicraft products from counterfeiting. According to ISO (international organization for standardization) 27001, authentication is defined as the process used to conform that a claimed characteristics or attributes that appears to be true is in fact true. With the aim of guaranteeing the authenticity of product, various methodological approaches have been devised over the past years and several authentication schemes have been proposed. Although it is a widely discussed and studied topic, authentication remains a crucial issue.More specifically, the main issue that the craft sector is facing is the lack of a structure for communicating a product information requested by the customer (e.g. tourist) due to the organization of the craft industry. As a result, several questions are emerging which authentication system for the craft industry. How to collect the product data and make it available to this system while guaranteeing its quality? How to guarantee a real time answer to the user (e.g. tourist)?Thereby, the project we are developing is oriented towards the management of data related to the product manufactured by Moroccan artisans to preserve its authenticity. Our objective is to conceive a traceability system to manage the information of handicraft product throughout its life cycle based on smartest authentication technologies and features.The Mobile Backend as a service (MBaaS) will help for sharing authentication information about goods in real time, as the request of the customer, in other way, this service will provide the answer about the product authenticity

Diffusion in phthalocyanine thin film layers: study by AES, EELS, EPES and electrical measurements

Diffusion studies are necessary to the feasibility of molecular pn junctions. Electrical and spectroscopic measurements have been done in two superimposed phthalocyanine thin layers: Zinc phthaiocyanine (PcZn) (p material) and Lutetium bisphthalocyanine (PC$_2$Lu) (n material). These measurements are in a good agreement. In spite of the very large dimensions of these molecules, diffusion and doping of PcZn by PC$_2$Lu occur. Moreover, elastic peak electron spectroscopy (EPES) seems more available than Auger electron spectroscopy (AES) to follow the diffusion in such samples.Les études de diffusion sont nécessaires pour utiliser pratiquement les semiconducteurs organiques – en particulier pour la réalisation de jonctions pn. Des mesures électriques et spectroscopiques ont été faites sur des couches minces de phtalocyanines superposées : phtalocyanine de Zinc(PcZn) (matériau de type p) et bisphtalocyanine de Lutetium (PC$_2$Lu) (matériau de type n). L'ensemble de ces mesures est en bon accord, la diffusion et le dopage de PcZn par PC$_2$Lu se produisent malgré la taille importante de ces molécules. De plus la spectroscopie de pic élastique (EPES) semble être plus adaptée à ces mesures que la spectroscopie d'électrons Auger (AES) pour suivre la diffusion dans ces échantillons

Tampering with springs: phosphorylation of titin affecting the mechanical function of cardiomyocytes

Reversible post-translational modifications of various cardiac proteins regulate the mechanical properties of the cardiomyocytes and thus modulate the contractile performance of the heart. The giant protein titin forms a continuous filament network in the sarcomeres of striated muscle cells, where it determines passive tension development and modulates active contraction. These mechanical properties of titin are altered through post-translational modifications, particularly phosphorylation. Titin contains hundreds of potential phosphorylation sites, the functional relevance of which is only beginning to emerge. Here, we provide a state-of-the-art summary of the phosphorylation sites in titin, with a particular focus on the elastic titin spring segment. We discuss how phosphorylation at specific amino acids can reduce or increase the stretch-induced spring force of titin, depending on where the spring region is phosphorylated. We also review which protein kinases phosphorylate titin and how this phosphorylation affects titin-based passive tension in cardiomyocytes. A comprehensive overview is provided of studies that have measured altered titin phosphorylation and titin-based passive tension in myocardial samples from human heart failure patients and animal models of heart disease. As our understanding of the broader implications of phosphorylation in titin progresses, this knowledge could be used to design targeted interventions aimed at reducing pathologically increased titin stiffness in patients with stiff hearts