The effect of external pressure on skin temperature distribution by thermography

1) Serial thermograms were taken after the application of various intensities and durations of localized pressure on the medial surface of the human forearm. 2) Thermal response of the body surface to localized pressure was quantified. 3) It was found that usually a time period of between 1 to 3 minutes elapsed before the body surface attained a maximum elevation of temperature from the time the localized pressure is removed. 4) It was found that increased intensity of pressure (5 psi vs. 3 psi) and longer duration (20 minutes vs. 10 minutes) caused larger thermal responses. 5) It is suggested that high resolution medical thermography may eventually become a useful tool in the fitting of prosthetic and orthotic devices and for the prediction of pressure sores formation so prophylactic measures can be started immediately on immobilized patients.     

DNA damage produced by povidone-iodine in cultured human diploid cells

Povidone-iodine is capable of selective altering the DNA of human diploid cells growing in culture. This finding extends to eukaryotic cells, the previously reported DNA-modifying activity of this agent for bacteria. In view of the known relationship between DNA-modifying activity and potential carcinogenicity, the results suggest that the potential hazards posed by the widespread use of this agent be evaluated.     

Rates of extraction of mercaptan sulfur from pentane by caustic solution

The interphase rate process for the extraction of mercaptan sulfur from n-pentane with a 10% caustic solution is examined. The system represents a case of mass transfer with an equilibrium chemical reaction occurring in one phase. Experimental studies were made with both a continuous flow stirred tank reactor (CFSTR) and an annular flow jet reactor (AFJR). The interphase volumetric mass transfer coefficient (K_La) was derived based on Olander's theory. The K_La data for each contactor was found to be a function of the power input per unit volume. The AFJR exhibited higher K_La values and equilibration of mercaptan sulfur was achieved in about three milliseconds.