Automated circuit fabrication and direct characterization of carbon nanotube vibrations.

Since their discovery, carbon nanotubes have fascinated many researchers due to their unprecedented properties. However, a major drawback in utilizing carbon nanotubes for practical applications is the difficulty in positioning or growing them at specific locations. Here we present a simple, rapid, non-invasive and scalable technique that enables optical imaging of carbon nanotubes. The carbon nanotube scaffold serves as a seed for nucleation and growth of small size, optically visible nanocrystals. After imaging the molecules can be removed completely, leaving the surface intact, and thus the carbon nanotube electrical and mechanical properties are preserved. The successful and robust optical imaging allowed us to develop a dedicated image processing algorithm through which we are able to demonstrate a fully automated circuit design resulting in field effect transistors and inverters. Moreover, we demonstrate that this imaging method allows not only to locate carbon nanotubes but also, as in the case of suspended ones, to study their dynamic mechanical motion.

Antepartum management protocol. Timing and mode of delivery in gestational diabetes.

We sought to determine whether strict glycemic control during diabetic pregnancy combined with elective early induction of labor reduces the rate of cesarean delivery and fetal birth trauma. We used a population-based longitudinal design covering three periods corresponding to changes in the management protocol for diabetic pregnancy at our center: 1) 1980-1989: no set level of maternal glycemia, elective cesarean section when estimated fetal weight was 4,500 g or more, and no elective early induction; 2) 1990-1992: desired mean maternal glycemia < or = 5.8 mmol/l, elective cesarean section when estimated fetal weight was 4,000 g or more, and elective early induction at 40 weeks for large-for-gestational-age fetuses; 3) 1993-1995: desired mean maternal glycemia < or = 5.3 mmol/l, elective cesarean section when estimated fetal weight was 4,000 g or more, and elective early induction at 38 weeks for large-for-gestational-age fetuses. Outcome of diabetic pregnancies was compared for the three periods, relative to that of the normal population. There was a gradual, constant, and significant decline in the incidence of macrosomia (17.9, 14.9, and 8.8%, respectively; P < 0.05) and large-for-gestational-age fetuses (23.6, 21.0, and 11.7%; P < 0.05) coupled with a gradual, nonsignificant decrease in cesarean deliveries (20.6, 18.4, and 16.2%) and in cases of shoulder dystocia (1.5, 1.2, and 0.6%), to rates close to those of the normal population. Our data show that maintaining strict control of maternal diabetes and adhering to an active management protocol for early elective delivery based on the estimated fetal weight have a significant effect on reducing the rate of macrosomia, thereby affecting the incidence of both traumatic births and cesarean deliveries.