Accelerating 4D image reconstruction for magnetic resonance-guided radiotherapy.

Background And Purpose: Physiological motion impacts the dose delivered to tumours and vital organs in external beam radiotherapy and particularly in particle therapy. The excellent soft-tissue demarcation of 4D magnetic resonance imaging (4D-MRI) could inform on intra-fractional motion, but long image reconstruction times hinder its use in online treatment adaptation. Here we employ techniques from high-performance computing to reduce 4D-MRI reconstruction times below two minutes to facilitate their use in MR-guided radiotherapy.

Layered materials as a platform for quantum technologies.

Layered materials are taking centre stage in the ever-increasing research effort to develop material platforms for quantum technologies. We are at the dawn of the era of layered quantum materials. Their optical, electronic, magnetic, thermal and mechanical properties make them attractive for most aspects of this global pursuit.

Distributed large-scale graph processing on FPGAs.

Processing large-scale graphs is challenging due to the nature of the computation that causes irregular memory access patterns. Managing such irregular accesses may cause significant performance degradation on both CPUs and GPUs. Thus, recent research trends propose graph processing acceleration with Field-Programmable Gate Arrays (FPGA).

Peer Support Specialist Work and Experiences During the COVID-19 Pandemic: A National Longitudinal Study.

Objective: The study followed up with peer support specialists (PSSs) responding to an earlier survey to assess the pandemic's continued employment and personal effects.

Methods: A December 2020 online survey was conducted with respondents to a May 2020 survey. Items on employment status, work tasks, challenges, support, and benefits were included.

Tuning the Optical Properties of a MoSe Monolayer Using Nanoscale Plasmonic Antennas.

Nanoplasmonic systems combined with optically active two-dimensional materials provide intriguing opportunities to explore and control light-matter interactions at extreme subwavelength length scales approaching the exciton Bohr radius. Here, we present room- and cryogenic-temperature investigations of a MoSe monolayer on individual gold dipole nanoantennas. By controlling nanoantenna size, the dipolar resonance is tuned relative to the exciton achieving a total tuning of ∼130 meV.

Impact of COVID-19 on Peer Support Specialists in the United States: Findings From a Cross-Sectional Online Survey.

Objective: Peer support specialists (PSS) are an integral part of the mental health workforce. The purpose of this study was to better understand how the COVID-19 pandemic affected their employment status and day-to-day work.

Methods: A cross-sectional, online survey was conducted (May-June 2020).

Room-Temperature Synthesis of 2D Janus Crystals and their Heterostructures.

Janus crystals represent an exciting class of 2D materials with different atomic species on their upper and lower facets. Theories have predicted that this symmetry breaking induces an electric field and leads to a wealth of novel properties, such as large Rashba spin-orbit coupling and formation of strongly correlated electronic states. Monolayer MoSSe Janus crystals have been synthesized by two methods, via controlled sulfurization of monolayer MoSe and via plasma stripping followed thermal annealing of MoS .

Charge-tuneable biexciton complexes in monolayer WSe.

Monolayer transition metal dichalcogenides have strong Coulomb-mediated many-body interactions. Theoretical studies have predicted the existence of numerous multi-particle excitonic states. Two-particle excitons and three-particle trions have been identified by their optical signatures.

Excitonic Emission of Monolayer Semiconductors Near-Field Coupled to High-Q Microresonators.

We present quantum yield measurements of single layer WSe (1L-WSe) integrated with high-Q ( Q > 10) optical microdisk cavities, using an efficient (η > 90%) near-field coupling scheme based on a tapered optical fiber. Coupling of the excitonic emission is achieved by placing 1L-WSe in the evanescent cavity field. This preserves the microresonator high intrinsic quality factor ( Q > 10) below the bandgap of 1L-WSe.

Large-scale quantum-emitter arrays in atomically thin semiconductors.

Quantum light emitters have been observed in atomically thin layers of transition metal dichalcogenides. However, they are found at random locations within the host material and usually in low densities, hindering experiments aiming to investigate this new class of emitters. Here, we create deterministic arrays of hundreds of quantum emitters in tungsten diselenide and tungsten disulphide monolayers, emitting across a range of wavelengths in the visible spectrum (610-680 nm and 740-820 nm), with a greater spectral stability than their randomly occurring counterparts.

p-wave triggered superconductivity in single-layer graphene on an electron-doped oxide superconductor.

Electron pairing in the vast majority of superconductors follows the Bardeen-Cooper-Schrieffer theory of superconductivity, which describes the condensation of electrons into pairs with antiparallel spins in a singlet state with an s-wave symmetry. Unconventional superconductivity was predicted in single-layer graphene (SLG), with the electrons pairing with a p-wave or chiral d-wave symmetry, depending on the position of the Fermi energy with respect to the Dirac point. By placing SLG on an electron-doped (non-chiral) d-wave superconductor and performing local scanning tunnelling microscopy and spectroscopy, here we show evidence for a p-wave triggered superconducting density of states in SLG.

Long Spin Diffusion Length in Few-Layer Graphene Flakes.

We report a spin valve with a few-layer graphene flake bridging highly spin-polarized La_{0.67}Sr_{0.33}MnO_{3} electrodes, whose surfaces are kept clean during lithographic definition.

Atomically thin quantum light-emitting diodes.

Transition metal dichalcogenides are optically active, layered materials promising for fast optoelectronics and on-chip photonics. We demonstrate electrically driven single-photon emission from localized sites in tungsten diselenide and tungsten disulphide. To achieve this, we fabricate a light-emitting diode structure comprising single-layer graphene, thin hexagonal boron nitride and transition metal dichalcogenide mono- and bi-layers.

High Responsivity, Large-Area Graphene/MoS2 Flexible Photodetectors.

We present flexible photodetectors (PDs) for visible wavelengths fabricated by stacking centimeter-scale chemical vapor deposited (CVD) single layer graphene (SLG) and single layer CVD MoS2, both wet transferred onto a flexible polyethylene terephthalate substrate. The operation mechanism relies on injection of photoexcited electrons from MoS2 to the SLG channel. The external responsivity is 45.

Science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems.

We present the science and technology roadmap for graphene, related two-dimensional crystals, and hybrid systems, targeting an evolution in technology, that might lead to impacts and benefits reaching into most areas of society. This roadmap was developed within the framework of the European Graphene Flagship and outlines the main targets and research areas as best understood at the start of this ambitious project. We provide an overview of the key aspects of graphene and related materials (GRMs), ranging from fundamental research challenges to a variety of applications in a large number of sectors, highlighting the steps necessary to take GRMs from a state of raw potential to a point where they might revolutionize multiple industries.

Older versus newer antidepressants: substance P or calcium antagonism?

Substance P (SP) is possibly involved in the pathophysiology of depression and anxiety. We investigated interactions between antidepressants on SP-induced effects and their potential calcium-blocking activity in the isolated guinea pig ileum. All the antidepressants tested, except pargyline, moclobemide, mianserin, and reboxetine, were able to inhibit in a concentration-dependent manner the contraction induced by 100 nmol/L SP.

Evaluation of gene expression in human lymphocytes activated in the presence of melatonin.

The effect of melatonin on the expression of genes previously correlated to T lymphocyte activation (HLA-DRB, thymosin beta 10 (beta-Tim)) and to Lymphokine Activated Killer (LAK) activity (beta-Tim, Tumour Rejection Antigen (TRA 1), nRap 2) was investigated in phytohemagglutinin (PHA)-stimulated human lymphocyte cultures. The aim was to find an enhancing effect of this substance on anti-tumoral immune defences as suggested by studies on tumour progression in mice and clinical immunotherapy trials in humans. mRNA obtained from melatonin-treated and -untreated PHA-stimulated lymphocytes was retrotranscribed and amplified by RT-PCR using primers based on the sequences of the selected genes.

[Andrenergic reactivity of the gastro-intestinal tract. I. Fundus of the rat's stomach].

The adrenergic receptors of the fundus of rat stomach are both type alpha and type beta. Activation of the alpha-adrenergic receptors gives a diphasic response in which inhibition precedes excitation. The beta-adrenergic receptors mediate exclusively inhibitory response; the beta-adrenergic component of the inhibitory response is clearly observed only when the alpha-adrenergic component is diminished.