Concentration-dependent viscosity and thermal radiation effects on MHD peristaltic motion of Synovial Nanofluid: Applications to rheumatoid arthritis treatment.

BACKGROUND AND OBJECTIVE: The biomedical fluid which fills the Synovial joint cavity is called Synovial fluid which behaves as in the fluid classifications to Non-Newtonian fluids. Also it's described as a several micrometers thick layer among the interstitial cartilages with very low friction coefficient. Consequently, the present paper opts to investigate the influence of the concentration-dependent viscosity on Magnetohydrodynamic peristaltic flow of Synovial Nanofluid in an asymmetric channel in presence of thermal radiation effect. METHOD: Our problem is solved for two models, in the first model which referred as Model-(I), viscosity is considered exponentially dependent on the concentration. Model-(2), Shear thinning index is considered as a function of concentration. Those models are introduced for the first time in peristaltic or Nanofluid flows literature. The governing problem is reformulated under the assumption of low Reynolds number and long wavelength. The resulting system of equations is solved numerically with the aid of Parametric ND Solve. RESULTS: Detailed comparisons have been made between Model-(I) and Model-(2) and found unrealistic results between them. Results for velocity, temperature and nanoparticle concentration distributions as well as pressure gradient and pressure rise are offered graphically for different values of various physical parameters. CONCLUSIONS: Such models are applicable to rheumatoid arthritis (RA) treatment. Rheumatoid arthritis patients can be treated by applying the magnetic field on an electrically conducting fluid, due to the movement of the ions within the cell which accelerates the metabolism of fluids.

The effects of local X-irradiation on the distensibility of the rectum in rats.

Proctometry was performed on female Wistar rats following irradiation of the rectum with single doses of 15, 18 and 22 Gy of X-rays. The results indicated a progressive increase in distensibility until week 29 after irradiation which was attributed to degenerative changes in the intestinal wall. A major factor which determines colorectal pressure is the neuromuscular activity, however, neuromuscular transmission was not affected by irradiation.

Gross morphologic and functional effects of postoperative radiation on free jejunal autografts.

Twenty adult mongrel dogs underwent free jejunal transplants to the neck; 10 either died of or had to be sacrificed as a result of postoperative complications, 5 received a 55-Gy-equivalent dose of radiation after 3 weeks, and 5 were followed as controls. Serial manometric and endoscopic evaluations were performed over a 9-month period. Progressive deterioration of the quality and amplitude of peristalsis of the jejunal autografts was observed only in the radiated group. In addition, all dogs in the radiated group developed severe jejunal circumferential constriction and stricture formation. These delayed effects of irradiation on revascularized jejunal autografts should be considered in planning the method of pharyngoesophageal reconstruction as well as the timing of adjuvant radiotherapy.

The opossum as an animal model for studying radiation esophagitis.

Six opossums were evaluated as a possible animal model of radiation esophagitis. In a single exposure to the esophagus, four animals received 60Co radiation of various doses; two served as controls. Pre- and postirradiation evaluations using fiberoptic endoscopy, mucosal biopsy, barium esophagography, and manometry were performed. Esophagitis developed at one week in irradiated animals. Opossums receiving 17.5, 20, and 22.5 Gy (1,750; 2,000; and 2,250 rad) became anorexic one week postirradiation, and abnormal motility subsequently developed. The controls and the animal receiving 15 Gy (1,500 rad) remained normal. Histological changes in the irradiated opossum esophagus resembled those found in humans.