235 research outputs found
PIC methods in astrophysics: Simulations of relativistic jets and kinetic physics in astrophysical systems
The Particle-In-Cell (PIC) method has been developed by Oscar Buneman,
Charles Birdsall, Roger W. Hockney, and John Dawson in the 1950s and, with the
advances of computing power, has been further developed for several fields such
as astrophysical, magnetospheric as well as solar plasmas and recently also for
atmospheric and laser-plasma physics. Currently more than 15 semi-public PIC
codes are available which we discuss in this review. Its applications have
grown extensively with increasing computing power available on high performance
computing facilities around the world. These systems allow the study of various
topics of astrophysical plasmas, such as magnetic reconnection, pulsars and
black hole magnetosphere, non-relativistic and relativistic shocks,
relativistic jets, and laser-plasma physics. We review a plethora of
astrophysical phenomena such as relativistic jets, instabilities, magnetic
reconnection, pulsars, as well as PIC simulations of laser-plasma physics
(until 2021) emphasizing the physics involved in the simulations. Finally, we
give an outlook of the future simulations of jets associated to neutron stars,
black holes and their merging and discuss the future of PIC simulations in the
light of petascale and exascale computing.Comment: 117 pages, 44 figures, Invited review article for Living Reviews in
Computational Astrophysics, comments are welcomed, Living Reviews in
Computational Astrophysics, submitted, 2020, the revised version resubmitted
in December 2020, the second revised revision resubmitted in April, 2021,
publishe
Electromagnetically levitated vibration isolation system for the manufacturing process of silicon monocrystals
This paper introduces a study on an Electromagnetically Levitated Vibration Isolation System (ELVIS) for isolation control of large-scale vibration. This system features no mechanical contact between the isolation table and the installation floor, using a total of four electromagnetic actuators which generate magnetic levitation force in the vertical and horizontal directions. The configuration of the magnet for the vertical direction is designed to prevent any generation of restoring vibratory force in the horizontal direction. The isolation system is set so that vibration control effects due to small earthquakes can be regulated to below 5(gal) versus horizontal vibration levels of the installation floor of up t 25(gal), and those in the horizontal relative displacement of up to 30 (mm) between the floor and levitated isolation table. In particular, studies on the relative displacement between the installation floor and the levitated isolation table have been made for vibration control in the horizontal direction. In case of small-scale earthquakes (Taft wave scaled: max. 25 gal), the present system has been confirmed to achieve a vibration isolation to a level below 5 gal. The vibration transmission ratio of below 1/10 has been achieved versus continuous micro-vibration (approx. one gal) in the horizontal direction on the installation floor
A randomized, double-blind, placebo-controlled phase III trial of duloxetine in Japanese fibromyalgia patients
Generalised Acanthosis Nigricans in Childhood with Short Stature Associated with Poor Response to Growth Hormone Provocation
Acanthosis nigricans (AN) is a skin disorder characterised by skin hyperpigmentation and thickening, especially in the intertriginous regions. AN is usually classified as either malignant, benign, obesity-associated, syndromic, unilateral, acral, drug-induced and mixed (1). A generalised form of AN frequently occurs together with internal malignancy in adult patients, but it is rare in childhood (2-7). Here, we report a paediatric case of generalised AN associated with short stature accompanied with decreased growth hormone levels.ArticleACTA DERMATO-VENEREOLOGICA. 94(4):486-487 (2014)journal articl
Rashba-Dresselhaus spin-orbit coupling and polarization-coupled luminescence in an organic single crystal microcavity
Spin-orbit coupling (SOC) of light plays a fundamental photophysics that is
important for various fields such as materials science, optics, and quantum
technology, contributing to the elucidation of new physical phenomena and the
development of innovative applications. In this study, we investigate the
impact of SOC in a microcavity system using the highly oriented molecular
crystal. The unique molecular alignment of our crystal creates substantial
optical anisotropy, enabling the observation of significant SOC effects within
a microcavity form. Through angle-resolved photoluminescence measurements and
theoretical calculations, the presence of Rashba-Dresselhaus (RD) SOC in the
lower branch of polariton modes is revealed. We have observed for the first
time polarization-coupled emission from polariton modes due to the RD-SOC
effect in a microcavity with a medium having both strong light-matter coupling
and strong optical anisotropy. Theoretical investigations further elucidate the
intricate interplay between the RD-SOC effect and anisotropic light-matter
coupling, leading to the emergence of both circularly and diagonally polarized
mode splittings. This study not only advances our understanding of optical SOC
in microcavities but also highlights the potential of highly oriented molecular
crystals in manipulating SOC effects without external electric or magnetic
fields. These findings offer greatly promising platforms for developing
topological photonics and quantum technologies
Optimizing Charge Switching in Membrane Lytic Peptides for Endosomal Release of Biomacromolecules.
Endocytic pathways are practical routes for the intracellular delivery of biomacromolecules. Along with this, effective strategies for endosomal cargo release into the cytosol are desired to achieve successful delivery. Focusing on compositional differences between the cell and endosomal membranes and the pH decrease within endosomes, we designed the lipid-sensitive and pH-responsive endosome-lytic peptide HAad. This peptide contains aminoadipic acid (Aad) residues, which serve as a safety catch for preferential permeabilization of endosomal membranes over cell membranes, and His-to-Ala substitutions enhance the endosomolytic activity. The ability of HAad to destabilize endosomal membranes was supported by model studies using large unilamellar vesicles (LUVs) and by increased intracellular delivery of biomacromolecules (including antibodies) into live cells. Cerebral ventricle injection of Cre recombinase with HAad led to Cre/loxP recombination in a mouse model, thus demonstrating potential applicability of HAad in vivo
Preliminary reports of the Quaternary sediment core drilled in Nakatokushima-cho Tokushima City, West Japan
A 80 m-long borehole core (TK-B-1) drilled in the Tokushima Plain was examined. Based on the sedimentary facies, volcanic ash layers, pollen fossils and radiocarbon dates, this core was divided into the following 13 units. Unit 1 is a metamorphic rock that forms the base of the Tokushima Plain. Units 3 to 8 are Pleistocene and consist of marine and fluvial strata. Units 12-10 are considered to be Alluvium based on radiocarbon dates, and K-Ah tephra found in Unit 11. In Unit 10, we found a volcanic glass concentration derived from AT tephra, but the concentration is a possibility of rework. We intend to reveal the subsurface geological structure of the Tokushima Plain based on the database of borehole data, lithologic stratigraphy, volcanic ash stratigraphy and biostratigraphy
State- and water repellency-controllable molecular glass of pillar[5]arenes with fluoroalkyl groups by guest vapors
Molecular glasses are low-molecular-weight organic compounds that are stable in the amorphous state at room temperature. Herein, we report a state- and water repellency-controllable molecular glass by n-alkane guest vapors. We observed that a macrocyclic host compound pillar[5]arene with the C₂F₅ fluoroalkyl groups changes from the crystalline to the amorphous state (molecular glass) by heating above its melting point and then cooling to room temperature. The pillar[5]arene molecular glass shows reversible transitions between amorphous and crystalline states by uptake and release of the n-alkane guest vapors, respectively. Furthermore, the n-alkane guest vapor-induced reversible changes in the water contact angle were also observed: water contact angles increased and then reverted back to the original state by the uptake and release of the n-alkane guest vapors, respectively, along with the changes in the chemical structure and roughness on the surface of the molecular glass. The water repellency of the molecular glass could be controlled by tuning the uptake ratio of the n-alkane guest vapor
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