Reactive plasma cleaning and restoration of transition metal dichalcogenide monolayers

The cleaning of two-dimensional (2D) materials is an essential step in the fabrication of future devices, leveraging their unique physical, optical, and chemical properties. Part of these emerging 2D materials are transition metal dichalcogenides (TMDs). So far there is limited understanding of the cleaning of “monolayer” TMD materials. In this study, we report on the use of downstream H2 plasma to clean the surface of monolayer WS2 grown by MOCVD. We demonstrate that high-temperature processing is essential, allowing to maximize the removal rate of polymers and to mitigate damage caused to the WS2 in the form of sulfur vacancies. We show that low temperature in situ carbonyl sulfide (OCS) soak is an efficient way to resulfurize the material, besides high-temperature H2S annealing. The cleaning processes and mechanisms elucidated in this work are tested on back-gated field-effect transistors, confirming that transport properties of WS2 devices can be maintained by the combination of H2 plasma cleaning and OCS restoration. The low-damage plasma cleaning based on H2 and OCS is very reproducible, fast (completed in a few minutes) and uses a 300 mm industrial plasma etch system qualified for standard semiconductor pilot production. This process is, therefore, expected to enable the industrial scale-up of 2D-based devices, co-integrated with silicon technology

Mapping the Spatial Distribution of Charge Carriers in LaAlO3/SrTiO3 Heterostructures

At the interface between complex insulating oxides, novel phases with interesting properties may occur, such as the metallic state reported in the LaAlO3/SrTiO3 system. While this state has been predicted and reported to be confined at the interface, some works indicate a much broader spatial extension, thereby questioning its origin. Here we provide for the first time a direct determination of the carrier density profile of this system through resistance profile mappings collected in cross-section LaAlO3/SrTiO3 samples with a conducting-tip atomic force microscope (CT-AFM). We find that, depending upon specific growth protocols, the spatial extension of the high-mobility electron gas can be varied from hundreds of microns into SrTiO3 to a few nanometers next to the LaAlO3/SrTiO3 interface. Our results emphasize the potential of CT-AFM as a novel tool to characterize complex oxide interfaces and provide us with a definitive and conclusive way to reconcile the body of experimental data in this system.Comment: This updated version contains new experimental dat

Fluoxetine targets an allosteric site in the enterovirus 2C AAA+ ATPase and stabilizes a ring-shaped hexameric complex

Enteroviruses are globally prevalent human pathogens responsible for many diseases. The nonstructural protein 2C is a AAA+ helicase and plays a key role in enterovirus replication. Drug repurposing screens identified 2C-targeting compounds such as fluoxetine and dibucaine, but how they inhibit 2C is unknown. Here, we present a crystal structure of the soluble and monomeric fragment of coxsackievirus B3 2C protein in complex with (S)-fluoxetine (SFX), revealing an allosteric binding site. To study the functional consequences of SFX binding, we engineered an adenosine triphosphatase (ATPase)-competent, hexameric 2C protein. Using this system, we show that SFX, dibucaine, HBB [2-(α-hydroxybenzyl)-benzimidazole], and guanidine hydrochloride inhibit 2C ATPase activity. Moreover, cryo-electron microscopy analysis demonstrated that SFX and dibucaine lock 2C in a defined hexameric state, rationalizing their mode of inhibition. Collectively, these results provide important insights into 2C inhibition and a robust engineering strategy for structural, functional, and drug-screening analysis of 2C proteins

ADDovenom: Thermostable Protein-Based ADDomer Nanoparticles as New Therapeutics for Snakebite Envenoming

Snakebite envenoming can be a life-threatening medical emergency that requires prompt medical intervention to neutralise the effects of venom toxins. Each year up to 138,000 people die from snakebites and threefold more victims suffer life-altering disabilities. The current treatment of snakebite relies solely on antivenom—polyclonal antibodies isolated from the plasma of hyperimmunised animals—which is associated with numerous deficiencies. The ADDovenom project seeks to deliver a novel snakebite therapy, through the use of an innovative protein-based scaffold as a next-generation antivenom. The ADDomer is a megadalton-sized, thermostable synthetic nanoparticle derived from the adenovirus penton base protein; it has 60 high-avidity binding sites to neutralise venom toxins. Here, we outline our experimental strategies to achieve this goal using state-of-the-art protein engineering, expression technology and mass spectrometry, as well as in vitro and in vivo venom neutralisation assays. We anticipate that the approaches described here will produce antivenom with unparalleled efficacy, safety and affordability

Divergent selection for residual food intake in Rhode Island Red egg-laying lines : gross carcase composition, carcase adiposity and lipid contents of tissues

Chantier qualité spécifique "Auteurs Externes" département de Génétique animale : uniquement liaison auteur au référentiel HR-AccessInternational audienc

Value of Gilliatt's pneumatic tourniquet test for diagnosis of carpal tunnel syndrome.

In 1953, Gilliatt and Wilson described the pneumatic-tourniquet test to diagnose the carpal tunnel syndrome (CTS). It was originally carried out by inflating a brachial cuff at suprasystolic pressure, looking for the appearance of dysesthesiae; several authors later proposed to perform it at infrasystolic pressure, arguing that it would better reflect the elevated venous pressure supposed to be present in CTS. The purpose of this study was to compare both methods.Journal ArticleRandomized Controlled TrialSCOPUS: ar.jinfo:eu-repo/semantics/publishe

Formation of epitaxial strontium oxide and silicate on silicon (001)

International audienc

Hetero-epitaxy of SrTiO3 on Si and control of the interface

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Two dimensional Sr silicate grown on Si(001) studied using X-ray Photoelectron Spectroscopy

We used X-ray Photoemission Spectroscopy (XPS) to study the structural and chemical properties of SrO grown by Molecular Beam Epitaxy (MBE) on Si(001) substrates in the following conditions: (i) low temperature growth at 30°C and (ii) high temperature growth at 500°C. The crystalline quality of the film deposit was controlled in-situ by Reflection High-Energy Electron Diffraction (RHEED). The results show the growth, at low temperature of epitaxial SrO; and at high temperature the formation of crystalline silicate

Improvement of the electrochemical performance by partial chemical substitution into the lithium site of titanium phosphate-based electrode materials for lithium-ion batteries: LiNi0.25Ti1.5 Fe0.5(PO4)3

Partial lithium substitution with nickel (0.25 of Ni2+ ion) in the previously reported Li1.5Fe0.5Ti1.5(PO4)3/C (LFTP@C) was performed to improve its structural and electrochemical properties. The new LiNi0.25Fe0.5Ti1.5(PO4)3/C (LNFTP@C) material was then tested as electrode for lithium ion batteries. In the voltage window 1.85V–3.0 V vs. Li+/Li, attractive electrochemical performances were obtained, mostly in terms of rate capability performance. At a current rate of 0.1C (6.6 mAg−1), the material delivered a capacity of around 120 mAhg−1, while at 5C, we observed a slight drop of the specific capacity reaching a value of 108 mAhg−1. Long-term cycling performance stability was also tested demonstrating a remarkable capacity decrease during the last 500 cycles. The capacity retention decreased from 94% to 91% after 500 cycles to about 77% and 74% after 1000 cycles at fast current rates of 5C (329.8 mAg−1) and 10C (659.6 mAg−1), respectively. In the wider voltage window, an average specific capacity of around 380 mAhg−1 was attained at a slow current rate of 0.1C