Application of the U-N method to the reflected critical slab problem for one-speed neutrons with forward and backward scattering

WOS: 000245230000010The U-N method is used to solve the critical slab problem for reflecting boundary conditions in one-speed neutron transport theory. The isotropic scattering kernel with the combination of forward and backward scattering is chosen for the neutrons in a uniform finite slab. It is shown that the method converges rapidly with easily executable equations. The presented numerical results are compared with the results available in the literature

The Effects of Nitric Oxide Donor Molsidomine on Skeletal Muscle Damage in a Rat Hind Limb Model of Ischemia-Reperfusion

Background: In this experimental study, we aimed to examine the protective effect of molsidomine (MS), a nitric oxide (NO) donor, against ischemia-reperfusion (I-R) injury in a rat skeletal muscle model. Methods: Ischemia was achieved by application of an elastic rubber band as high as possible on the left thigh of the rats. Group 1: the control group received a sham operation. Group 2: the I-R group received I-R injury to the left hind limbs. Group 3: the I-R/MS group underwent the same model of I-R injury and received MS. Group 4: the I-R/L -NAME (N-omega-nitro-L-arginine-methyl ester) group underwent the same model of I-R injury and received L -NAME, an inhibitor of NO synthase. Results: In groups 2 and 4, malondialdehyde increased significantly when compared to groups 1 and 3. Superoxide dismutase, catalase and glutathione peroxidase increased significantly in group 3 compared to groups 2 and 4. The NO levels were significantly elevated in group 3 compared to groups 2 and 4. In addition, the histopathological score was considerably lower in group 3 than in group 4. The number of necrotic muscle fibers and infiltration of neutrophils were significantly reduced in the MS-treated group. Conclusions: These findings suggest that MS can exert a protective effect against skeletal muscle injury caused by I-R in the rats. Copyright (C) 2008 S. Karger AG, Base

T-N approximation to reflected slab and computation of the critical half thicknesses

WOS: 000238203000011The criticality solution to one-speed neutron transport equation using the T-N approximation is described for reflected slab. In the solution, Marshak type boundary condition is used. The critical half thicknesses are computed for different values of c and reflection coefficients. Computations are made by using the both T-N and P-N approximation for the comparison. (C) 2005 Elsevier Ltd. All rights reserved

Oxidative stress in human in sustained and white coat hypertension

Oxidative stress is thought to play a critical role in the pathogenesis of hypertension. Protein oxidation is defined here as the covalent modification of a protein induced either directly by reactive oxygen species or indirectly by reaction with secondary by-products of oxidative stress. The aim of our study was to evaluate the protein oxidation and to examine the function of the antioxidative system in sustained and white coat hypertensives (WCH) and compare with normotensives. This study was designed to investigate the protein oxidation parameters [protein carbonyls (PCOs)] in sustained hypertensives (17 males and 20 females) and WCH (18 males and 19 females). PCO and the endogenous antioxidant components protein thiol (P-SH), CuZn-superoxide dismutase (CuZn-SOD) and glutathione (GSH) were analysed using spectrophotometric and kinetic methods. Sustained hypertensive and WCH groups exhibited higher protein oxidation and lower P-SH, CuZn-SOD and GSH activities than normotensives. With regard to these parameters, there was no significant difference between sustained hypertensive and WCH groups. Blood pressure correlates positively with PCO groups and negatively with others. There exists an imbalance between oxidants and antioxidants in WCH because of the increase of oxidants associated with the decrease of antioxidant capacity. This may cause endothelial dysfunction just like in sustained hypertension. It may be necessary to add antioxidants to conventional antihypertensive therapy to balance the oxidative status in WCH