RESUMO
Thermo-responsive, biocompatible polyurethane (PU) with shape memory properties is highly desirable for biomedical applications. An innovative approach to producing wound closure strips using shape memory polymers (SMPs) is of significant interest. In this work, PU composed of polycaprolactone (PCL) and 1,4-butanediol (BDO) was synthesized using two-step polymerization. Palm oil (PO) was added to PU for enhancing the Young's modulus of the PU beyond the set criterion of 130 MPa. It was found that PU had the ability to crystallize at room temperature and the segments of individual PCL and BDO polyurethanes crystallized separately. The crystalline domains and hard segment of PU greatly affected the tensile properties. The reduction of crystalline domains by the addition of PO and deformation at the higher melting temperature of the crystalline PCL polyurethane phase improved the shape fixity and shape recovery ratios. The new irreversible phase, raised from the permanent deformation upon stretching at the between melting temperature of the crystalline PCL and BDO polyurethanes of 70 °C, resulted in a decrease in shape fixity ratio after the first thermomechanical stretching-recovering cycles. The demonstration of PU as a wound closure strip showed its efficiency and potential until the surgical wound healed.
RESUMO
OBJECTIVE: To assess associated factors of uncontrolled blood pressure and complications of hypertension in hypertensive rural Thai populations. MATERIAL AND METHOD: A cross-sectional study was conducted in hypertensive rural Thai people aged > or =35 years-old in Baan Nayao, Chachoengsao Province, Thailand. Blood pressure (BP) was measured and questionnaires were answered. After 12-hr fasting, blood samples were taken for determining plasma glucose, lipid profiles and serum creatinine. Morning urine samples were collected for microalbuminuria testing and electrocardiography (ECG) was performed to detect left ventricular hypertrophy (LVH). RESULTS: Of the 289 participants (97 males and 192 females) mean duration of hypertension was 4.29 +/- 4.95 years and 61.5% did not achieve target BP control. Among participants who had ECG performed and urine sample investigation, 15.7% demonstrated LVH and 25.3% had microalbuminuria. In uncontrolled BP participants, 20% had LVH and 24.8% had microalbuminuria whereas in controlled BP participants, 7.8% had LVH and 26.1% had microalbuminuria. Uncontrolled BP was associated with males, dyslipidemia, diabetes, abdominal obesity, metabolic syndrome, always having salty food and salts added for seasoning. The independent risks of uncontrolled BP were hypertensive male (OR = 2.48, 95% CI = 1.07-5.76) and metabolic syndrome (OR = 2.59, 95% CI = 1.24-5.40). Males were also at risk for LVH (OR = 2.86, 95% CI = 1.31-6.23) and history of lipid disorders was a risk of microalbuminuria (OR = 3.13, 95% CI = 1.47-6.67). CONCLUSION: Males and metabolic syndrome were independently associated with uncontrolled BP in hypertensive participants. Males had more risk than females to develop LVH and having history of lipid disorders lead to microalbuminuria occurrence. Thus, life style modification may prove beneficial to these rural hypertensive participants.
