High-performance liquid chromatographic separation of C-15-epimers of 15-methylprostaglandin E2 methyl ester and 15-methylprostaglandin E2

A high-performance liquid chromatographic system that permits quantitation of 15-methylprostaglandin E2 and its methyl ester is described. Separation from the corresponding C-15 epimers is effected by adsorption chromatography on microparticulate silica with refractive index detection.     

Fractures of the femoral shaft: a prospective study of closed intramedullary nailing, modified open intramedullary nailing, and cast-bracing

One hundred twelve consecutive fractures of the femoral diaphysis were treated in a prospective study at Grady Memorial Hospital, a designated trauma center, during the three-year period 1978 through 1980. Fifty of these were treated by closed intramedullary nailing; all united. Of the rest, 20 were treated by modified open intramedullary nailing, and 42 by cast-bracing. Closed intramedullary nailing offered a significant reduction in hospitalization and healing times compared to the other two methods; however, the high cost of equipment, along with the added cost of reoperation to remove the nail, rendered cast-bracing economically superior. Fractures treated by modified open intramedullary nailing developed no infections, but these patients lost significantly more blood during operation than those treated by closed nailing. Because of the decreased hospitalization and healing times, we prefer the closed intramedullary nailing technic for use in selected femoral fractures treated during the acute phase by an experienced surgical team.     

Selftuning control of some pilot plant processes

This paper reviews the results of some experimental tests carried out to evaluate the performance of selftuning (ST) controllers for temperature control of a continuous stirred tank heater, composition control of a binary distillation column and pH control of an acidic effluent. All the pilot plant units have been controlled using a single variant selftuning control, and a newly developed multivariant ST controller was used for simultaneous control of the terminal compositions of the distillation column. The control performance of the units operating under ST control is compared to that obtained using very well tuned proportional plus integral (PI) or proportional plus integral plus derivative (PID) conventional controllers. Control of pH is shown using a technique of electrochemical neutralisation coupled with a single variant ST controller. The control algorithms have been programmed on a number of microprocessor- and minicomputer-based systems. Z80 for stirred tank heater control, LS1-11 for pH control and HP1000 distributed computer system for distillation control.     

Influence of human chorionic gonadotropin on pregnancy rates in lactating dairy and beef cows

Single subcutaneous injection of 1500 IU human chorionic gonadotropin or placebo injections were given at the time of insemination in lactating dairy and beef cows to determine their effects on rates of pregnancy. Pregnancy rates at first service in 161 control and 145 treated dairy cows were 52.8% and 44.8%, respectively. Similar rates for 136 control and 145 treated beef cows were 54.4% and 54.5%. Injections of human chorionic gonadotropin were not effective in stimulating conception rates in lactating dairy or beer cows under field conditions.