416 research outputs found
Gravitational Fragmentation of Expanding Shells. I. Linear Analysis
We perform a linear perturbation analysis of expanding shells driven by
expansions of HII regions. The ambient gas is assumed to be uniform. As an
unperturbed state, we develop a semi-analytic method for deriving the time
evolution of the density profile across the thickness. It is found that the
time evolution of the density profile can be divided into three evolutionary
phases, deceleration-dominated, intermediate, and self-gravity-dominated
phases. The density peak moves relatively from the shock front to the contact
discontinuity as the shell expands. We perform a linear analysis taking into
account the asymmetric density profile obtained by the semi-analytic method,
and imposing the boundary conditions for the shock front and the contact
discontinuity while the evolutionary effect of the shell is neglected. It is
found that the growth rate is enhanced compared with the previous studies based
on the thin-shell approximation. This is due to the boundary effect of the
contact discontinuity and asymmetric density profile that were not taken into
account in previous works.Comment: 13 pages, 13 figures, to be published in the Astrophysical Journa
Charge Transfer Cross Sections for Multiply Charged Slow Ne, Ar, Kr and Xe Ions on Various Gas Targets : II. Molecular Gas Targets
Observed charge transfer cross sections are compiled, similarly to Part I, for multiply charged Ne, Ar, Kr and Xe ions on several molecular targets in an energy region from a few to tens keV. The projectiles are recoil ions produced by using our “ion-impact ion source” (IIIS). The values are compared with the results of other research workers
<Abstract of annual report>Inhibitory Effects of Glucocorticoids on Increased Vascular Permeability Caused by Passive Cutaneous Anaphylaxis and Some Chemical Mediators in Rats.
Auto-Luminescent Genetically-Encoded Ratiometric Indicator for Real-Time Ca2+ Imaging at the Single Cell Level
Background: Efficient bioluminescence resonance energy transfer (BRET) from a bioluminescent protein to a fluorescent protein with high fluorescent quantum yield has been utilized to enhance luminescence intensity, allowing single-cell imaging in near real time without external light illumination. Methodology/Principal Findings: We applied BRET to develop an autoluminescent Ca2+ indicator, BRAC, which is composed of Ca^[2+]-binding protein, calmodulin, and its target peptide, M13, sandwiched between a yellow fluorescent protein variant, Venus, and an enhanced Renilla luciferase, RLuc8. Adjusting the relative dipole orientation of the luminescent protein's chromophores improved the dynamic range of BRET signal change in BRAC up to 60%, which is the largest dynamic range among BRET-based indicators reported so far. Using BRAC, we demonstrated successful visualization of Ca2+ dynamics at the single-cell level with temporal resolution at 1 Hz. Moreover, BRAC signals were acquired by ratiometric imaging capable of canceling out Ca^[2+]-independent signal drifts due to change in cell shape, focus shift, etc. Conclusions/Significance: The brightness and large dynamic range of BRAC should facilitate high-sensitive Ca2+ imaging not only in single live cells but also in small living subjects
An External Beam Method for Multi-Elemental Analysis of Heavy Metals in Stream Water
An improvement has been made on a liquid target preparation for an external proton beam PIXE which is regarded as an excellent technique for multi-elemental analysis. A 2 MeV proton beam taken out to the atmosphere through an exit Kapton foil bombards an acidic solution target directly. Such direct bombardment enables the direct comparison of X-ray yields of a liquid sample with those of the standard solution so that one can determine the elemental concentration in a liquid sample more precisely and easily. An example is given for the analysis of heavy metals in stream water
<Abstract of published report>Effect of a Newly Synthesized Leukotriene Antagonist, (E)-2,2-Diethyl-3\u27-2-2-(4-Isopropyl)Thiazolyl Ethenyl Succinanilic Acid (MCI-826), on Immunological Liver Injury and Nephritis in Mice.
<Abstract of annual report>Inhibitory effect of β-adrenergic stimulants on increased vascular permeability caused by passive cutaneous anaphylaxis, allergic mediators, and mediator releasers in rats.
<Abstract of published report>Effects of a Newly Synthesized Leukotriene Antagonist, NZ-107,on Immediate-Type Hypersensitivity Reaction in Rats and Guinea-Pigs.
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