Study on effect of hydrogen treatment on amorphous carbon film using scanning probe microscopy.

Amorphous carbon film was treated by hydrogen plasma. The change of surface structure, conductivity, and work function distribution is characterized by scanning probe microscope technique and local electron emission is also analyzed. We find that chemical effect of hydrogen plasma on the a-C film is small, but the etching effect is strong and the surface morphology and conductance are obviously changed after hydrogen treatment. Electron emission enhancement is not due to the decrease of work function or existence of sp(2) conductive channels, but from the mutual effect between sp(2) and sp(3) phase. We suggest that the enhancement is due to the internal electron injection from the sp(2)-rich interface layer into the surface sp(3)-rich grains.

Prediction of caesarean section from ultrasound and clinical assessment of fetal size.

One hundred and five women with singleton pregnancies and cephalic presentation were assessed. Fundal height and a clinical estimate of fetal weight were recorded. The fetal biparietal diameter, abdominal circumference and femur length were measured with ultrasound. Ultrasound estimated fetal weight was calculated using 3 different formulas (Shepard, Campbell and CUHK). The liquor volume was assessed using the amniotic fluid index. Ultrasound was able to predict Caesarean section with more reliability than clinical assessment of fetal size or weight. The biparietal diameter, fundal height and amniotic fluid index were poor predictors of mode of delivery. The measurements which best predicted the mode of delivery were the fetal femur length and abdominal circumference. Femur length, but not abdominal circumference, was a statistically better predictor of Caesarean section than clinical estimation of fetal weight. There was no improvement in prediction using ultrasound estimated fetal weight.

Randomized, double blind, placebo controlled comparison of ritodrine and hexoprenaline for tocolysis prior to external cephalic version at term.

External cephalic versions in the study period were performed in a double blind design by 2 experienced practitioners. Sixty-three patients were allocated to treatment with either placebo, ritodrine or hexoprenaline. The main outcome measure studied was successful completion of external cephalic version. Hexoprenaline, but not ritodrine, was statistically more likely to be associated with successful version than placebo (p = 0.04 versus p = 0.22).