SURFACE-TEMPERATURE CONTROL OF SILICON NANOWIRES IN DRY AND LIQUID CONDITIONS

In this paper we present the results of surface temperature control of silicon nanowires by using fluorescent thermometry at the nanometer scale. Rhodamine B is one of the stable fluorescent molecules, which rely on the characteristic of temperature-dependent change in fluorescent intensity, and it was used for nano-scale surface temperature sensing interface. The resistive heating on Si nanowires was carried out with applying voltage potential of 6 12 V. Surface-temperature measurement was performed by converting the changes in fluorescent intensity with calibration curve of Rhodamine B. The temperature at the central line along nanowires increasing from 30 degrees to 35-70 degrees was observed

Scalable Batch Fabrication of Ultrathin Flexible Neural Probes using Bioresorbable Silk Layer

International audienceFlexible deep brain probes have been the focus of many research works and aims at achieving better compliance with the surrounding brain tissue while maintaining minimal rejection. Strategies have been explored to find the best way to implant a flexible probe in the brain, while maintaining its flexibility once positioned in the cortex. Here, we present a novel and versatile scalable batch fabrication approach to deliver ultra-thin and flexible penetrating neural probe consisting of a silk-parylene bilayer. The biodegradable silk layer provides a temporary and programmable stiffener to ensure ease of insertion of the ultrathin parylene-based flexible devices. The innovative and yet robust batch fabrication technology allows complete design freedom of the neural probe in terms of materials, size, shape and thickness. These results provide a novel technological solution for implanting ultra-flexible and ultrathin devices, which possesses great potential for brain research

Spray-coated carbon nanotube carpets for creeping reduction of conducting polymer based artificial muscles

International audienceIt is often observed that during cyclic actuation conducting polymer based artificial muscles are continuously creeping from the initial movement range. One of the likely reasons of such behaviour is unbalanced charging during conducting polymer oxidation and reduction. In order to improve the actuation reversibility and subsequently the long time performance of ionic actuators, we suggest to use spray-coated carbon nanotube (CNT) carpets on the surface of the conducting polymer electrodes. We show that carbon nanotubes facilitate conducting polymer redox reaction and improve its reversibility. Consequently, in the long term, charge accumulation in the polymer film is avoided leading to significantly improved long term performance during cycling actuation

Silk and PEG as means to stiffen a parylene probe for insertion in the brain: toward a double time-scale tool for local drug delivery

International audienceThe use of soft materials as substrate for neural probes aims at achieving better compliance with the surrounding neurons while maintaining minimal rejection. Many strategies have emerged to enable such probes to penetrate the cortex, among which the use of resorbable polymers. We performed several tests involving two resorbable polymers considered most promising: polyethylene glycol (PEG) and silk fibroin (SF) from Bombyx Mori silkworms. Our coating method provides a repeatable, uniform structure optimized for a stress-reduced insertion of a parylene-C neural probe. Standard compression tests as well as in vitro and in vivo insertion assessments show that both SF and PEG-coated probes are stiff enough to avoid the buckling effect during insertion in the cortex. However, with a buckling force of 300 mN and a mechanical holding in vitro of tens of minutes, we assess silk fibroin to be more reliable for practical handling. In vivo first try-outs in mouse brain showed neither buckling issues of the probe nor undesired alteration of the signal recording. Moreover, we evidenced two distinct time scales in the bioresorption of our polymer coatings: silk fibroin degrades itself in a matter of weeks and PEG dissolves itself within seconds in the presence of water. We then present a hybrid PEG and SF coating that could be used as a drug delivery system with different time scales to reduce both the acute and the chronic body reaction

Tixagevimab-cilgavimab (AZD7442) for the treatment of patients hospitalized with COVID-19 (DisCoVeRy): A phase 3, randomized, double-blind, placebo-controlled trial

This work received funding from several sources: the European Commission (EU-Response, Grant 101015736), the DIM One Health Île-de-France (R20117HD) and Astra-Zeneca. We thank all participants who consented to enroll in the trial, as well as all study and site staff whose indispensable assistance made the conduct of the DisCoVeRy trial possible (all listed in the appendix, pp 27-36