University of Saskatchewan

About: University of Saskatchewan is a education organization based out in Saskatoon, Saskatchewan, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 25021 authors who have published 52579 publications receiving 1483049 citations. The organization is also known as: USask.

Occurrence and Removal of Antiviral Drugs in Environment: A Review

Abstract: Antiviral drugs have been recently recognized as one of the emerging contaminants in the environment. These are discharged after therapeutic use through human excretion. Effluent containing high concentration of antiviral drugs discharged from production facilities is also a cause of concern to nearby aquatic bodies. There is an increased interest in their removal because they are highly bioactive. Some antiviral drugs are resistant to conventional methods of degradation, and there is a risk of development of antiviral resistance in humans and animals if exposed repeatedly for long periods. To date, the potential human, animal, and ecological risks associated with the discharge of these antiviral compounds to the environment are not well documented. This study presents a brief summary on occurrence, ecotoxicological risks, and physicochemical properties of antiviral drugs in the environment. The needs regarding removal, disposal, and treatment of antiviral drugs are also addressed.

Increased oxidative stress in rat liver and pancreas during progression of streptozotocin-induced diabetes.

Abstract: 1. Oxygen free radicals have been suggested to be a contributory factor in complications of diabetes mellitus. There are many reports indicating the changes in parameters of oxidative stress in diabetes mellitus. In this study we aimed to identify whether oxidative stress occurs in the liver and pancreas in the initial stages of development of diabetes. 2. We therefore investigated the lipid peroxide level (thiobarbituric acid-reactive substances, TBARS) and activities of antioxidant enzymes [superoxide dismutase (SOD), catalase and glutathione peroxidase] in liver and pancreas of control and streptozotocin-induced diabetic rats at various stages of development of diabetes. 3. Male Sprague-Dawley rats were divided into two groups: group I, control (n = 42) and group II, diabetic (n = 42). Each group was further subdivided into seven groups consisting of six rats each. Rats in these subgroups were studied at weekly intervals (0 to 6 weeks). Plasma glucose levels, TBARS levels and activities of antioxidant enzymes were measured in liver and pancreas at various time intervals. 4. There was a significant (P < 0.05) and progressive increase in TBARS levels of liver and pancreas in the diabetic group. Total SOD and Cu-Zn-SOD activity increased (P < 0.05) with progression of diabetes while Mn-SOD activity showed no significant change in either tissue. Catalase and glutathione peroxidase activities increased significantly (P < 0.05) in liver and pancreas. 5. Immunohistochemical study of pancreatic islet revealed a decrease in the expression of insulin with progression of diabetes. However, glucagon and somatostatin showed an increase in immunoreactivity and a difference in their distribution pattern. 6. The findings of the present study suggest that oxidative stress starts at early onset of diabetes mellitus and increases progressively. In conclusion, the structural damage to these tissues or complications of diabetes mellitus may be due to oxidative stress.

Optimal switching device placement in radial distribution systems

Abstract: This paper presents a new formulation for power system sectionalizing device placement taking into consideration outage, maintenance and investments costs. The formulation of sectionalizing switches is a combinatorial constrained optimization problem with a nonlinear, nondifferentiable objective function. A solution methodology based on the optimization technique of simulated annealing, is proposed to determine: (i) the number of sectionalizing switches; and (ii) the locations of the switches. The proposed solution methodology can offer a global optimal solution for the sectionalizing device placement problem which includes the reliability, investment and maintenance costs.