High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) there is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups

Valorisation par voie hydrométallurgique de Matières Premières Secondaires

Cet exposé s'intéressera à la récupération par voie hydrométallurgique de métaux contenus dans les Matières Premières Secondaires. Dans un premier temps seront abordées des généralités sur les Métaux Critiques, leur taux de recyclage et les gisements identifiés. Deux exemples de traitement seront ensuite développés : le traitement de catalyseurs d'hydrotraitement et le traitement de poudres métallifères issues de broyats d'accumulateurs par couplage électrolixiviation/électrodéposition

Valorisation par voie hydrométallurgique de Matières Premières Secondaires

Cet exposé s'intéressera à la récupération par voie hydrométallurgique de métaux contenus dans les Matières Premières Secondaires. Dans un premier temps seront abordées des généralités sur les Métaux Critiques, leur taux de recyclage et les gisements identifiés. Deux exemples de traitement seront ensuite développés : le traitement de catalyseurs d'hydrotraitement et le traitement de poudres métallifères issues de broyats d'accumulateurs par couplage électrolixiviation/électrodéposition

Hydrodemetallation and Hydrodesulfurization Spent Catalysts Elemental Analysis: Comparison of Wavelength Dispersive X-ray Fluorescence and Atomic Emission Spectrometries

International audienc

Glutathionyl-hydroquinone reductases from poplar are plastidial proteins that deglutathionylate both reduced and oxidized glutathionylated quinones

International audienceGlutathionyl-hydroquinone reductases (GHRs) catalyze the deglutathionylation of quinones via a catalytic cysteine. The two GHR genes in the Populus trichocarpa genome, Pt-GHR1 and Pt-GHR2, are primarily expressed in reproductive organs. Both proteins are localized in plastids. More specifically, Pt-GHR2 localizes in nucleoids. At the structural level, Pt-GHR1 adopts a typical GHR fold, with a dimerization interface comparable to that of the bacterial and fungal GHR counterparts. Pt-GHR1 catalyzes the deglutathionylation of both reduced and oxidized glutathionylated quinones, but the enzyme is more catalytically efficient with the reduced forms

Flexible metal-oxide thin film transistor circuits for RFID and health patches

We discuss in this paper the present state and future perspectives of thin-film oxide transistors for flexible electronics. The application case that we focus on is a flexible health patch containing an analog sensor interface as well as digital electronics to transmit the acquired data wirelessly to a base station. We examine the electronic performance of amorphous Indium-Gallium-Zinc-Oxide (a-IGZO) during mechanical bending. We discuss several ways to further boost the electronic transistor performance of n-type amorphous oxide semiconductors, by modifying the semiconductor or by improving the transistor architecture. We show analog and digital circuits constructed with several architectures, all based on n-type-only amorphous oxide technology. From circuit point of view, the discovery of a p-type amorphous semiconductor matching known n-type amorphous semiconductors would be of great importance. The present best-suited p-type is SnO, but it is poly-crystalline in nature and shows some ambipolarity due to the presence of n-type SnO2. In search of a better p-type semiconductor, preferably amorphous, we present recent insights into the band structure of potential amorphous oxide p-type semiconductors