Glucocorticoids Inhibit Sodium Depletion-induced Salt Appetite in Rat

Glucocorticoids, produced in adrenal cortex, exert potent natriuretic and diuretic actions in the kidney. Recently, it has been found that glucocorticoids could upregulate the expression of natriuretic peptide receptor A (NPR-A), the primary receptor of atrial natriuretic peptide, in the hypothalamus of the rat. Consequently, systemic administration of glucocorticoid could block dehydration-induced water intake by activation hypothalamic NPR-A. We describe here glucocorticoids could inhibit sodium intake when administrated systemically in conscious, salt-depleted rats; an effect which was strong and long-lasting. The study provided further evidence for the actions of glucocorticoids on central nervous system, which together with their established renal actions coordinated to normalize extracellular fluid volume

Creep fatigue life assessment of a pipe intersection with dissimilar material joint by linear matching method

As the energy demand increases the power industry has to enhance both efficiency and environmental sustainability of power plants by increasing the operating temperature. The accurate creep fatigue life assessment is important for the safe operation and design of current and future power plant stations. This paper proposes a practical creep fatigue life assessment case of study by the Linear Matching Method (LMM) framework. The LMM for extended Direct Steady Cycle Analysis (eDSCA) has been adopted to calculate the creep fatigue responses due to the cyclic loading under high temperature conditions. A pipe intersection with dissimilar material joint, subjected to high cycling temperature and constant pressure steam, is used as an example. The closed end condition is considered at both ends of main and branch pipes. The impact of the material mismatch, transitional thermal load, and creep dwell on the failure mechanism and location within the intersection is investigated. All the results demonstrate the capability of the method, and how a direct method is able to support engineers in the assessment and design of high temperature component in a complex loading scenario