69 research outputs found
The ILW hierarchy
In this paper, we present a new hierarchy which includes the intermediate
long wave (ILW) equation at the lowest order. This hierarchy is thought to be a
novel reduction of the 1st modified KP type hierarchy. The framework of our
investigation is Sato theory.Comment: 8 pages, LaTeX2
Periodic ILW equation with discrete Laplacian
We study an integro-differential equation which generalizes the periodic
intermediate long wave (ILW) equation. The kernel of the singular integral
involved is an elliptic function written as a second order difference of the
Weierstrass zeta-function. Using Sato's formulation, we show the integrability
and construct some special solutions. An elliptic solution is also obtained. We
present a conjecture based on a Poisson structure that it gives an alternative
description of this integrable hierarchy. We note that this Poisson algebra in
turn is related to a quantum algebra related with the family of Macdonald
difference operators.Comment: 17 pages. To appear in J. Phys. A: Math. Theo
Cancer of the Pancreas in 125 Patients
In this report, we did a retrospective study of 125 patients with cancer of the pancreas. Seventeen (36.2%) of the 47 patients with cancer of the pancreatic head underwent resection; 11.2% died within 30 days of surgery, 33.3 survived the first year, and 13.3 survived the first three years. The longest survival was for five years. Nine (23%) of the 39 patients with cancer of the pancreatic body and tail underwent resection; 11.1% died within 30 days, 37.5% survived the first year, and none survived more than three years. The longest survival was for 35 months. Important factors affecting the prognosis were invasion by the cancer of veins or lymph vessels in the surrounding tissues, and metastasis to regional lymph nodes. Lymphatic drainage of small cancers of the pancreatic head were established early. Invasion to the retroperitoneal tissue in cancer of the pancreatic body and tail was more common than in cancer of the pancreatic head. For the patient of early cancer of the pancreas, we strongly recommend total pancreatectomy over WHIPPLE\u27s pancreatoduodenectomy, based on results of our analysis of the outcome in our patients following these two operations. Key words: Cancer of the pancreas, Total pancreatectomy, WHIPPLE\u27s pancreatoduodenectom
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