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.

Superconductivity in hydrogen dominant materials: Silane

Abstract: The metallization of hydrogen directly would require pressure in excess of 400 gigapascals (GPa), out of the reach of present experimental techniques. The dense group IVa hydrides attract considerable attention because hydrogen in these compounds is chemically precompressed and a metallic state is expected to be achievable at experimentally accessible pressures. We report the transformation of insulating molecular silane to a metal at 50 GPa, becoming superconducting at a transition temperature of Tc = 17 kelvin at 96 and 120 GPa. The metallic phase has a hexagonal close-packed structure with a high density of atomic hydrogen, creating a three-dimensional conducting network. These experimental findings support the idea of modeling metallic hydrogen with hydrogen-rich alloy.

The development of disability in rheumatoid arthritis.

Abstract: Six hundred eighty-one consecutive patients with rheumatoid arthritis were followed for an average of 11.9 years to identify initial factors that predicted subsequent disability. Of 39 potentially predictive variables obtained at study onset and studied by stepwise regression methods, age was found to be the most powerful single predictor of disability, followed by radiologic grade, sex, and initial functional class. The worst prognosis for disability was found in patients who were older women and who showed radiologic worsening and developed functional impairment early in the disease course. Both disability and radiologic progression of disease were found to develop most rapidly during the first years after disease onset and to assume a slow, nearly linear rate of increase after 10 years. Approximately 10% of patients did not develop significant disability. This study suggests that it is possible to identify, early in the disease course, those patients who are likely to develop severe disability, and that "disease-modifying" therapy might well be initiated earlier in such patients and used consistently throughout the subsequent treatment.