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Stacking van der Waals crystals allows for the on-demand creation of a periodic potential landscape to tailor the transport of quasiparticle excitations. We investigate the diffusion of photoexcited electron-hole pairs, or excitons, at the interface of WS 2 /WSe 2 van der Waals heterostructure over a wide range of temperatures. We observe the appearance of distinct interlayer excitons for parallel and antiparallel stacking and track their diffusion through spatially and temporally resolved photoluminescence spectroscopy from 30 to 250 K. While the measured exciton diffusivity decreases with temperature, it surprisingly plateaus below 90 K. Our observations cannot be explained by classical models like hopping in the moiré potential. A combination of ab initio theory and molecular dynamics simulations suggests that low-energy phonons arising from the mismatched lattices of moiré heterostructures, also known as phasons, play a key role in describing and understanding this anomalous behavior of exciton diffusion. Our observations indicate that the moiré potential landscape is dynamic down to very low temperatures and that the phason modes can enable efficient transport of energy in the form of excitons.

Introduction: Physical activity is a major determinant in the prevention of chronic diseases, equally on the side effects of treatments and the consequences of the disease. It improves quality of life, but also reduces morbidity and mortality, and therefore health expenses. A sedentary lifestyle is the fourth cause of premature death in the world, in the context of chronic non-communicable diseases. In France, the prescription for adapted physical activity (APA) has been included in the law since 2016. With the development of "Maisons Sport santé", the Onco'sport program was developed to enable people affected by cancer to participate in adapted physical activity. The objective of our work is to explore the lived experience of cancer patients practicing adapted physical activity as part of the Onco'sport program., Methods: This is a qualitative study of 10 semi-directed individual interviews with patients participating in the Onco'sport program, recruited from the "Maison Sport Santé" from Nîmes and the association "Les Roses du Gard". A phenomenological analysis was carried out with a semiopragmatic approach., Results: For all participants, the APA through a program provides professional supervision of Physical Activity, influences adherence and builds confidence. This program is at the origin of changes in lifestyle habits and improves the relationship with illness and their cancer thanks to the physical and psychological benefits felt. Thus, APA appears as a full-fledged supportive care which requires informing patients and promoting it so that access is facilitated and becomes a standard. Health professionals including general practitioners do not currently have an important place in the promotion of APA, and patients most often obtain documentation on their own or through associations of patient., Conclusion: An APA program like Onco'sport is often the cause of a return to physical activity in patients, brings overall well-being and changes lifestyle habits. It seems important to promote physical activity to patients but also to the general population, given the benefits. This promotion involves easier access to this type of supervised program, financial support and better training of health professionals., (Copyright © 2024 Société Française du Cancer. Published by Elsevier Masson SAS. All rights reserved.)

Background: Long-term outcomes of patients with severe stroke remain poorly documented. We aimed to characterize one-year outcomes of patients with stroke requiring mechanical ventilation in the intensive care unit (ICU)., Methods: We conducted a prospective multicenter cohort study in 33 ICUs in France (2017-2019) on patients with consecutive strokes requiring mechanical ventilation for at least 24 hours. Outcomes were collected via telephone interviews by an independent research assistant. The primary end point was poor functional outcome, defined by a modified Rankin Scale score of 4 to 6 at 1 year. Multivariable mixed models investigated variables associated with the primary end point. Secondary end points included quality of life, activities of daily living, and anxiety and depression in 1-year survivors., Results: Among the 364 patients included, 244 patients (66.5% [95% CI, 61.7%-71.3%]) had a poor functional outcome, including 190 deaths (52.2%). After adjustment for non-neurological organ failure, age ≥70 years (odds ratio [OR], 2.38 [95% CI, 1.26-4.49]), Charlson comorbidity index ≥2 (OR, 2.01 [95% CI, 1.16-3.49]), a score on the Glasgow Coma Scale <8 at ICU admission (OR, 3.43 [95% CI, 1.98-5.96]), stroke subtype (intracerebral hemorrhage: OR, 2.44 [95% CI, 1.29-4.63] versus ischemic stroke: OR, 2.06 [95% CI, 1.06-4.00] versus subarachnoid hemorrhage: reference) remained independently associated with poor functional outcome. In contrast, a time between stroke diagnosis and initiation of mechanical ventilation >1 day was protective (OR, 0.56 [95% CI, 0.33-0.94]). A sensitivity analysis conducted after exclusion of patients with early decisions of withholding/withdrawal of care yielded similar results. We observed persistent physical and psychological problems at 1 year in >50% of survivors., Conclusions: In patients with severe stroke requiring mechanical ventilation, several ICU admission variables may inform caregivers, patients, and their families on post-ICU trajectories and functional outcomes. The burden of persistent sequelae at 1 year reinforces the need for a personalized, multi-disciplinary, prolonged follow-up of these patients after ICU discharge., Registration: URL: https://www., Clinicaltrials: gov; Unique identifier: NCT03335995., Competing Interests: Disclosures Dr Sonneville reports grants from the French Ministry of Health, outside the submitted work. Dr Mazighi reports compensation from Novo Nordisk for consultant services; compensation from Boerhinger-Ingelheim for consultant services; and compensation from Acticor Biotech for consultant services. Dr Cortier reports employment by Foch. Dr Geri reports compensation from BARD for consultant services. Dr Demoule reports compensation from Agence Européenne Informatique for other services; compensation from Fisher and Paykel Healthcare Limited for other services; compensation from Baxter Healthcare for other services; compensation from Lowenstein for other services; compensation from Getinge for other services; travel support from Lowenstein; compensation from AstraZeneca for other services; compensation from Lungpacer for other services; compensation from Liberate Medical for other services; compensation from Respinor for other services; and compensation from Mindray DS USA Inc. for other services. Dr Timsit reports grants from Merck; compensation from BD Biosciences for consultant services; and grants from Pfizer. The other authors report no conflicts.

Interlayer excitons, electron-hole pairs bound across two monolayer van der Waals semiconductors, offer promising electrical tunability and localizability. Because such excitons display weak electron-hole overlap, most studies have examined only the lowest-energy excitons through photoluminescence. We directly measured the dielectric response of interlayer excitons, which we accessed using their static electric dipole moment. We thereby determined an intrinsic radiative lifetime of 0.40 nanoseconds for the lowest direct-gap interlayer exciton in a tungsten diselenide/molybdenum diselenide heterostructure. We found that differences in electric field and twist angle induced trends in exciton transition strengths and energies, which could be related to wave function overlap, moiré confinement, and atomic reconstruction. Through comparison with photoluminescence spectra, this study identifies a momentum-indirect emission mechanism. Characterization of the absorption is key for applications relying on light-matter interactions.

Interlayer excitons (ILXs) - electron-hole pairs bound across two atomically thin layered semiconductors - have emerged as attractive platforms to study exciton condensation 1-4 , single-photon emission and other quantum information applications 5-7 . Yet, despite extensive optical spectroscopic investigations 8-12 , critical information about their size, valley configuration and the influence of the moiré potential remains unknown. Here, in a WSe 2 /MoS 2 heterostructure, we captured images of the time-resolved and momentum-resolved distribution of both of the particles that bind to form the ILX: the electron and the hole. We thereby obtain a direct measurement of both the ILX diameter of around 5.2 nm, comparable with the moiré-unit-cell length of 6.1 nm, and the localization of its centre of mass. Surprisingly, this large ILX is found pinned to a region of only 1.8 nm diameter within the moiré cell, smaller than the size of the exciton itself. This high degree of localization of the ILX is backed by Bethe-Salpeter equation calculations and demonstrates that the ILX can be localized within small moiré unit cells. Unlike large moiré cells, these are uniform over large regions, allowing the formation of extended arrays of localized excitations for quantum technology., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Moiré superlattices formed by van der Waals materials can support a wide range of electronic phases, including Mott insulators 1-4 , superconductors 5-10 and generalized Wigner crystals 2 . When excitons are confined by a moiré superlattice, a new class of exciton emerges, which holds promise for realizing artificial excitonic crystals and quantum optical effects 11-16 . When such moiré excitons are coupled to charge carriers, correlated states may arise. However, no experimental evidence exists for charge-coupled moiré exciton states, nor have their properties been predicted by theory. Here we report the optical signatures of trions coupled to the moiré potential in tungsten diselenide/molybdenum diselenide heterobilayers. The moiré trions show multiple sharp emission lines with a complex charge-density dependence, in stark contrast to the behaviour of conventional trions. We infer distinct contributions to the trion emission from radiative decay in which the remaining carrier resides in different moiré minibands. Variation of the trion features is observed in different devices and sample areas, indicating high sensitivity to sample inhomogeneity and variability. The observation of these trion features motivates further theoretical and experimental studies of higher-order electron correlation effects in moiré superlattices.

We report light emission around 1 eV (1240 nm) from heterostructures of MoS&#95;{2} and WSe&#95;{2} transition metal dichalcogenide monolayers. We identify its origin in an interlayer exciton (ILX) by its wide spectral tunability under an out-of-plane electric field. From the static dipole moment of the state, its temperature and twist-angle dependence, and comparison with electronic structure calculations, we assign this ILX to the fundamental interlayer transition between the K valleys in this system. Our findings gain access to the interlayer physics of the intrinsically incommensurate MoS&#95;{2}/WSe&#95;{2} heterostructure, including moiré and valley pseudospin effects, and its integration with silicon photonics and optical fiber communication systems operating at wavelengths longer than 1150 nm.

Naturally occurring benzoxanthenones, which belong to the vast family of lignans, are promising biologically relevant targets. They are biosynthetically produced by the oxidative dimerization of 2-propenyl phenols. In this manuscript, we disclose a powerful automated flow-based strategy for identifying and optimizing a cobalt-catalyzed oxidizing system for the bioinspired dimerization of 2-propenyl phenols. We designed a reconfigurable flow reactor associating online monitoring and process control instrumentation. Our machine was first configured as an automated screening platform to evaluate a matrix of 4 catalysts (plus the blank) and 5 oxidants (plus the blank) at two different temperatures, resulting in an array of 50 reactions. The automated screening was conducted on micromole scale at a rate of one fully characterized reaction every 26 min. After having identified the most promising cobalt-catalyzed oxidizing system, the automated screening platform was straightforwardly reconfigured to an autonomous self-optimizing flow reactor by implementation of an optimization algorithm in the closed-loop system. The optimization campaign allowed the determination of very effective experimental conditions in a limited number of experiments, which allowed us to prepare the natural products carpanone and polemannone B as well as synthetic analogues.

We investigate the valley Hall effect (VHE) in monolayer WSe 2 field-effect transistors using optical Kerr rotation measurements at 20 K. While studies of the VHE have so far focused on n -doped MoS 2 , we observe the VHE in WSe 2 in both the n - and p -doping regimes. Hole doping enables access to the large spin-splitting of the valence band of this material. The Kerr rotation measurements probe the spatial distribution of the valley carrier imbalance induced by the VHE. Under current flow, we observe distinct spin-valley polarization along the edges of the transistor channel. From analysis of the magnitude of the Kerr rotation, we infer a spin-valley density of 44 spins/μm, integrated over the edge region in the p -doped regime. Assuming a spin diffusion length less than 0.1 μm, this corresponds to a spin-valley polarization of the holes exceeding 1%.

A modular autonomous flow reactor combining monitoring technologies with a feedback algorithm is presented for the synthesis of the natural product carpanone. The autonomous self-optimizing system, controlled via MATLAB, was designed as a flexible platform enabling an adaptation of the experimental setup to the specificity of the chemical transformation to be optimized. The reaction monitoring uses either online high pressure liquid chromatography (HPLC) or in-line benchtop nuclear magnetic resonance (NMR) spectroscopy. The custom-made optimization algorithm derived from the Nelder-Mead and golden section search methods performs constrained optimizations of black-box functions in a multidimensional search domain, thereby assuming no a priori knowledge of the chemical reactions. This autonomous self-optimizing system allowed fast and efficient optimizations of the chemical steps leading to carpanone. This contribution is the first example of a multistep synthesis where all discrete steps were optimized with an autonomous flow reactor.