This paper addresses the modification of poly(dimethylsiloxane), i.e. PDMS, using plasma surface treatment and a novel application of the membrane created. A set of model compounds were analysed to determine their permeation through PDMS, both with and without plasma treatment. It was found that plasma treatment reduced permeation for the majority of compounds but had little effect on some compounds, such as caffeine, with results indicating that polarity plays an important role in permeation, as is seen in human skin. Most importantly, a direct correlation was observed between plasma-modified permeation data and literature data through calculation of membrane permeability (Kp) values suggesting plasma-modified silicone membrane (PMSM) could be considered as a suitable in vivo replacement to predict clinical skin permeation.

This paper addresses the modification of poly(dimethylsiloxane), i.e. PDMS, using plasma surface treatment and a novel application of the membrane created. A set of model compounds were analysed to determine their permeation through PDMS, both with and without plasma treatment. It was found that plasma treatment reduced permeation for the majority of compounds but had little effect on some compounds, such as caffeine, with results indicating that polarity plays an important role in permeation, as is seen in human skin. Most importantly, a direct correlation was observed between plasma-modified permeation data and literature data through calculation of membrane permeability (Kp) values suggesting plasma-modified silicone membrane (PMSM) could be considered as a suitable in vivo replacement to predict clinical skin permeation.

Surveys of noncommunicable diseases were performed in six communities in Papua New Guinea during 1985-1986. Results are reported here with respect to blood pressure and associated factors in adults. Mean systolic and diastolic blood pressures were lowest, and hypertension was rarest (less than 2%), in three rural/semirural villages on Karkar Island, Madang Province. Intermediate values for blood pressure and moderate prevalence of hypertension (3-6%) were observed in rural and urban Tolai communities in East New Britain Province. A periurban village in the Eastern Highlands Province displayed the highest mean blood pressures and prevalence of hypertension (12% in men and 5% in women). There was a modest rise in mean systolic blood pressure with age in most groups, but the age-related rise in diastolic pressure was much less pronounced. Other cardiovascular risk factors--body mass index (BMI), and plasma cholesterol, glucose and insulin concentrations--were lowest in the least developed rural villages on Karkar Island and highest in the urban Tolai and periurban highland communities. Both systolic and diastolic blood pressures were significantly (and positively) related to age, male sex, BMI and speaking a non-Austronesian language. It is concluded that there is now a considerable variation in the prevalence of hypertension, and the levels of blood pressure and other cardiovascular risk factors, in different communities in Papua New Guinea.
Adult ; Blood Pressure ; Cardiovascular Diseases - etiology ; Diabetes Mellitus - epidemiology ; Hypertension - complications ; Obesity - epidemiology ; Papua New Guinea