12,194 research outputs found
Current-Induced Resonant Motion of a Magnetic Vortex Core: Effect of Nonadiabatic Spin Torque
The current-induced resonant excitation of a magnetic vortex core is
investigated by means of analytical and micromagnetic calculations. We find
that the radius and the phase shift of the resonant motion are not correctly
described by the analytical equations because of the dynamic distortion of a
vortex core. In contrast, the initial tilting angle of a vortex core is free
from the distortion and determined by the nonadiabaticity of the spin torque.
It is insensitive to experimentally uncontrollable current-induced in-plane
Oersted field. We propose that a time-resolved imaging of the very initial
trajectory of a core is essential to experimentally estimate the
nonadiabaticity.Comment: 4 pages, 4 figure
Ray class invariants over imaginary quadratic fields
Let be an imaginary quadratic field of discriminant less than or equal to
-7 and be its ray class field modulo for an integer greater
than 1. We prove that singular values of certain Siegel functions generate
over by extending the idea of our previous work. These generators
are not only the simplest ones conjectured by Schertz, but also quite useful in
the matter of computation of class polynomials. We indeed give an algorithm to
find all conjugates of such generators by virtue of Gee and Stevenhagen
EFFECTS OF CELLULAR HETEROGENEITY AND IMMUNE CELLS IN ANGIOTENSIN II-INFUSED HEMORRHAGED ASCENDING AORTAS
A previous thoracic aortic aneurysm time course study from our laboratory determined that ascending aortic dilation was significantly increased by day 5, and reached a plateau by day 28 of angiotensin II (AngII) infusion. We also found that mice had hemorrhage localized to the ascending aortas by day 5 of AngII infusion. The purpose of these studies was to provide mechanistic insight into the development of AngII-induced ascending aortic hemorrhage.
Male C57BL/6 mice fed normal diet were subcutaneously infused with either AngII (1000 ng/kg/min) or saline for 5 days. To examine cellular heterogeneity, hemorrhaged ascending aortas were collected and sectioned serially for histological staining and immunostaining. I was unable to identify an entry point for blood into the media of the aortic root and ascending aorta. However, I found incomplete intimo-medial dissection near the hemorrhaged regions that may potentially be contiguous with the blood. To investigate infiltration of immune cells during AngII infusion, immunohistochemistry of hemorrhaged ascending aortas was performed. The numbers of macrophages and neutrophils in AngII-infused aortas were increased in both medial and adventitial areas when compared with saline-infused aortas.
Therefore, infiltration of immune cells at the point of dissection is associated with aortic hemorrhage during AngII infusion
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