A functional differential equation which is nonlinear and involves forward and backward deviating arguments is solved numerically. The equation models conduction in a myelinated nerve axon in which the myelin completely insulates the membrane, so that the potential change jumps from node to node. The equation is of first order with boundary values given at t = +/- infinity. The problem is approximated via a difference scheme which solves the problem on a finite interval by utilizing an asymptotic representation at the endpoints, cubic interpolation and iterative techniques to approximate the delays, and a continuation method to start the procedure. The procedure is tested on a class of problems which are solvable analytically to access the scheme's accuracy and stability, then applied to the problem that models propagation in a myelinated axon. The solution's dependence on various model parameters of physical interest is studied. This is the first numerical study of myelinated nerve conduction in which the advance and delay terms are treated explicitly.

Animals↗

PubMed1983

[Study on berberine ion selective electrode].

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Berberine↗

PubMedDate not supplied

Pediatric Salmonella enterocolitis in a teaching hospital in Taitung: A four-year analysis.

In order to understand the childhood Salmonella enterocolitis in Taitung, we retrospectively collected the patients with the diagnosis of acute enterocolitis who were admitted to the pediatric wards of Taitung branch of Mackay Memorial Hospital from January 1, 1995 to December 31, 1998. Salmonella enterocolitis accounted for 16.8% of the total cases of acute enterocolitis. The mean age of the patients was 14.6 +/- 14.1 months old. Seventy-nine patients were male and 78 patients were female. Eighty-two patients lived in the urban area and 75 patients lived in the suburbs. The mean duration from onset of illness to admission was 2.6 +/- 1.9 days. The mean duration of hospitalization was 6.6 +/- 4.8 days. The peak incidence was in August and September. The most common clinical manifestations were fever (74.5%) and blood stool (46.5%). In 157 patients, Salmonella serogroup B was isolated from stool in 115 patients. The rate of bacteremia was 4.5%. Serogroup D accounted for 28.6% of the bacteremia. Two patients developed meningitis and one patient had osteomyelitis. Of 88 patients examined for rotavirus, 12 had positive results. There was neither bowel perforation nor mortality recorded in our study.

Bacteremia↗