28 research outputs found
An integral transform on a cylinder and the twistor correspondence
Twistor correspondences for R-invariant indefinite self-dual conformal
structures on R^4 are established explicitly. These correspondences are written
down by using a natural integral transform from functions on a two dimensional
cylinder to functions on the flat Lorentz space R^{1,2} which is related to the
wave equation and the Radon transform. A general method on the twistor
construction of indefinite self-dual 4-spaces and indefinite Einstein-Weyl
3-spaces are also summarized.Comment: 15 page
Singular Self-dual Zollfrei Metrics and Twistor Correspondence
We construct examples of singular self-dual Zollfrei metrics explicitly, by
patching a pair of Petean's self-dual split-signature metrics. We prove that
there is a natural one-to-one correspondence between these singular metrics and
a certain set of embeddings of to which has one singular point.
This embedding corresponds to an odd function on that is rapidly decreasing
and pure imaginary valued. The one-to-one correspondence is explicitly given by
using the Radon transform.Comment: 25page
Acute superior mesenteric venous thrombosis with advanced gastric cancer: a case report
Although the advanced stages of neoplasms have a risk of superior mesenteric venous thrombosis (MVT), an initial clinical diagnosis of MVT is sometimes difficult and it can be treated as a cancer-related pain using NSAIDs and/or opioids