Spectral and Texture Properties of Hydrophobic Aerogel Powders Obtained from Room Temperature Drying.

Attenuated Total Reflectance Infrared (ATR-IR) spectroscopy and texture measurements based on nitrogen adsorption-desorption isotherms are combined to characterize silica aerogel granules with different degrees of hydrophobicity. The aerogels were prepared from tetraethoxysilane via a room temperature hydrolysis-gelation process, solvent exchange, hydrophobization, and drying at subcritical conditions. The dependencies between the texture properties, pore architectures, surface fractal dimensions, and degree of hydrophobicity of the samples are extracted from the ATR-IR spectra and the adsorption-desorption isotherms. The IR absorption in the region of the Si-O-Si and Si-OH vibrations is used for a description of the structural and chemical changes in aerogel powders connected with their surface hydrophobization. The Frenkel-Halsey-Hill (FHH) theory is applied to determine the surface fractal dimension of the powder species.

Quantitative cardiotocography to improve fetal assessment during labor: a preliminary randomized controlled trial.

OBJECTIVE: To evaluate the effectiveness of a computerized decision support system, referred to as "quantitative cardiotocography" (qCTG), to reduce adverse birth outcomes compared to conventional CTG with fetal blood sampling. STUDY DESIGN: A preliminary parallel randomized control trial in a tertiary maternity hospital (Sofia, Bulgaria) was conducted with a sample size of 360 women per trial arm (N=720). Women in labor were recruited between March 2008 and March 2011. Unadjusted relative risks were derived to assess the effect of qCTG on outcomes of interest. A ROC curve was derived to determine the sensitivity and specificity of qCTG to detect acidemia (Clinical trial registration: Current Controlled Trials, http://www.controlled-trials.com/, ISRCTN46449237). MAIN OUTCOME MEASURES: Primary outcomes were hypoxia (cord-artery blood pH<7.20), acidemia (umbilical-artery blood pH<7.05), cesarean delivery, and forceps extraction. Secondary outcomes were Apgar score <7 at five minutes, neonatal seizures, and admission to the neonatal intensive care unit (NICU). RESULTS: Reduced risks were observed for all outcomes of interest in women monitored using qCTG. There was a significant reduction in hypoxia (RR: 0.53; 0.33, 0.84), acidemia (RR: 0.31; 95% CI: 0.12, 0.84), cesarean delivery (95% CI: 0.45, 0.85), and admission to the NICU (RR: 0.33; 95% CI: 0.14, 0.77) in women monitored using qCTG versus conventional CTG. CONCLUSION: qCTG may reduce risk of adverse birth outcomes; however, the small sample size and long recruitment period in this trial may overstate the benefits of this intervention. Further large-scale randomized control trials with sufficient sample size to detect rare adverse events are required prior to the adoption of qCTG in daily clinical practice.