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Abstract

La synovite villonodulaire (SVN) est une maladie rare avec une incidence de 1,8 cas pour 1 000 000 d’habitants. La SVN de cheville est peu décrite et évaluée car très rare (2,5 % des cas de SVN). Elle présente un taux de récidive de 11 %. Nous rapportons une série rétrospective continue avec pour objectif principal d’évaluer cliniquement et radiologiquement ces chevilles à la recherche d’éventuels facteurs de risque de récidive. À la révision, le critère principal d’étude était l’existence d’une récidive locale (radioclinique) et le critère secondaire l’existence d’une arthrose tibiotalienne. L’hypothèse de travail était qu’une éventuelle récidive pouvait être infraclinique justifiant une imagerie systématique dans le suivi.

Both optical and electrochemical graphene-based sensors have gone through rapid development, reaching high sensitivity at low cost and with fast response time. However, the complex validating biochemical operations, needed for their consistent use, currently limits their effective application. We propose an integration strategy for optoelectrochemical detection that overcomes previous limitations of these sensors used separately. We develop an optoelectrochemical sensor for aptamer-mediated protein detection based on few-layer graphene immobilization on selectively modified fluorine-doped tin oxide (FTO) substrates. Our results show that the electrochemical properties of graphene-modified FTO samples are suitable for complex biological detection due to the stability and inertness of the engineered electrodic interface. In addition, few-layer immobilization of graphene sheets through electrostatic linkage with an electrochemically grafted FTO surface allows obtaining an optically accessible and highly conductive platform. As a proof of concept, we used insulin as the target molecule to reveal in solution. Because of its transparency and low sampling volume (a few microliters), our sensing unit can be easily integrated in lab-on-a-chip cell culture systems for effectively monitoring subnanomolar concentrations of proteins relevant for biomedical applications.

Cellulose nanocrystal (CNC) is a promising building block for the bottom-up assembly of novel lightweight renewable materials. The ability to engineer the interfacial properties of CNC is of paramount importance to develop assembled materials for various applications; yet it remains a challenge to manipulate the supramolecular interactions within the cellulosic nanomaterials in a controlled manner. In this context, we demonstrate in this article how the assembly and mechanical properties of cellulose thin films can be controlled by manipulating the interfacial interactions of TEMPO-oxidized cellulose nanocrystals (TOCNCs) grafted with two different amino acids, arginine and tryptophan. The amino acid grafting onto the cellulose scaffold was confirmed in aqueous solutions by 1H NMR spectroscopy and in solid form by FTIR and XPS techniques. The surface functionalization of TOCNCs with simple cationic and aromatic groups provides a strategy for tuning the assembly of the nanostructures based on different supramolecular cross-linking interactions, including hydrogen bonds, π–π stacking, and cation–π interactions. In particular, we show that nanocellulose chains cross-linked by the non-covalent cation–π interactions lead to the formation of a laminated superstructure with high deformation and load standing capabilities. Our work provides a versatile strategy for tuning the surface properties of nanocellulose and represents an important step toward the development of sustainable materials with tailored mechanical properties, which will enable a wider application range of this building block all the way from tissue-engineering scaffolds to flexible devices.

This paper presents a diamond gammavoltaic cell – a solid state device which converts gamma radiation into electricity - with a novel design and promising capabilities. Gammavoltaics pose a unique challenge among radiovoltaics due to the highly penetrating nature of gamma rays. Adapting existing radiovoltaic and dosimeter designs by increasing their thickness risks throttling the flowing current, due to an attendant increase in series resistance. The presented design partially decouples this relationship, by creating a low-coverage hydrogen-terminated collection volume around the device, exploiting the transfer doping effect. This paper proves that hydrogen termination is necessary for the gammavoltaism exhibited. Data are then presented from current-voltage curves taken using synchrotron radiation, over the range 50 – 150 keV. A drop in series resistance over the range is discovered, and linked to the transition from the photoelectric effect to Compton scattering. The cell produces an open-circuit voltage VOC= 0.8 V. Its short-circuit current ISCand maximum power Pmaxare found to also depend on photon energy, reaching maxima at ∼ 150 keV, where ISC> 10 μA and Pmax> 3 μW, normalised in flux to 2 × 1011γ.s-1. Groundwork is hence laid for developing this type of cell for micropower applications.