A randomised controlled trial on suture materials for skin closure at caesarean section: Do wound infection rates differ?

UNLABELLED: Objective.The aim of this study was to determine wound complication rates following the use of suture materials and staples for skin closure at caesarean section (CS). STUDY DESIGN: A randomised, controlled, prospective study was undertaken. Results. A total of 1 100 women was assigned randomly into 3 groups: polyglycolic acid (PGA) suture group (N=361), skin staple (SS) group (N=373) and nylon suture group (N=366). The overall wound infection rate was 7%. There was no difference in respect of number of patients, age, parity and gestation between the study groups. Those who had nylon sutures as opposed to PGA sutures were 9.5 times more likely to experience wound infection (p=0.055). Women who had SS were at 6.93 times higher risk of wound infection than those who had PGA sutures (p=0.014). Other factors influencing wound infection rates included: rupture of membranes >12 hours were 13.7 times (95% confidence interval (CI) 3.9 - 47.9, p<0.0001) more likely to have wound infection than those with rupture of membranes <12 hours. For every 1-minute increase of surgery duration, the risk of infection increased 1.094 times (95% CI 1.046 - 1.145; p<0.0001). HIV-infected women were 53.4% less likely to develop wound infection than their uninfected counterparts (odds ratio 0.466, 95% CI 0.238 - 0.913; p=0.026). As the time period of observation increased from baseline to day 3 and from day 3 to day 10, wound infection risk increased by 35 times (95% CI 8.155 - 150.868; p<0.001). Conclusion.The use of SS for CS wound closure is associated with a significantly greater risk of wound infections. SS for wound closure at CS is not recommended for use in South African district hospitals.

High yield fabrication of chemically reduced graphene oxide field effect transistors by dielectrophoresis.

We demonstrate high yield fabrication of field effect transistors (FET) using chemically reduced graphene oxide (RGO) sheets. The RGO sheets suspended in water were assembled between prefabricated gold source and drain electrodes using ac dielectrophoresis. With the application of a backgate voltage, 60% of the devices showed p-type FET behavior, while the remaining 40% showed ambipolar behavior. After mild thermal annealing at 200 degrees C, all ambipolar RGO FET remained ambipolar with increased hole and electron mobility, while 60% of the p-type RGO devices were transformed to ambipolar. The maximum hole and electron mobilities of the devices were 4.0 and 1.5 cm(2) V( - 1) s( - 1) respectively. High yield assembly of chemically derived RGO FET will have significant impact in scaled up fabrication of graphene based nanoelectronic devices.