Accurate High-Pressure Measurements of Carbon Monoxide's Electrical Properties

Accurate measurements of carbon monoxide's electrical properties were carried out at high pressure for the first time enabling stringent comparisons with theoretical values calculated ab initio. Dielectric permittivity measurements were conducted utilising a microwave re-entrant cavity resonator over the temperature range from (255 to 313) K and at pressures up to 8 MPa with a relative combined expanded uncertainty (k=2) less than or equal to 52 ppm. The new data enable carbon monoxide's molar polarizability to be correlated within 0.5 %, significantly improving upon existing literature data, which have a relative scatter of about 10 %. The measured molecular polarizability and electric dipole moment of carbon monoxide were determined to be 2.176×10^-40  C²  m²  J^-1 and 0.107 D. Literature values from ab initio calculations for these properties are within 0.28 % and 3.9 %, respectively, of the measured quantities. Moreover, our measurement of the electric dipole moment at finite temperature agrees within 2.2 % with the value derived from accurate spectroscopic measurements for the ground rovibrational state. The second dielectric virial coefficient of carbon monoxide was determined experimentally for the first time to be b_ϵ =(1.015±0.044) cm³  mol^-1 , which compares reasonably with ab initio estimates.

[Active screening for genetic pathology in newborns. I. Registration of congenital abnormalities]

Active screening for genetic pathology over a period of 12 years (1990-2001) involved examination of 29,629 newborns at the Clinic of Obstetrics and Gynaecology. Congenital anomalies were detected in 1244 cases (live-, stillbirths and terminated pregnancies) which gives an average incidence rate of 42.0 per 1000 among the studied population. Congenital cardiac anomalies and CA of the central nervous system were the most common types of isolated CA. They provided frequencies of 7.76 per 1000 and 6.85 per 1000 cases respectively. The incidence of the neural tube defects (NTD), particularly, varied throughout the years (t = 2.69; p < 0.01) but stated high--on average 2.12 per 1000 with the highest rate of 3.89 per 1000 in 1993. A reduction in the incidence of NTD is possible with a recommendation of periconceptional folic acid supplementation. Registration of CA is a strategy for identifying families at risk to give births of child with CA. This approach enabled us to provide more accurate genetic counselling and prenatal diagnosis for genetic pathology. Active screening of newborn population is likely to be an effective and necessary service.

[Postnatal screening for congenital anomalies--the possibility of detecting families at high genetic risk]

The aim of the study was to present out experience with the registration of congenital anomalies (CA) and to assess the effect of the preventive genetic-consultative activities in affected families. In the period 1990-1996, 19174 infants born or hospitalized at the Clinic of Obstetrics, Pleven were screened for CA, showing frequency of 26.1%. Structural analysis of the CA is presented. 226 out of 500 (45%) families with and affected child were consulted by a geneticist. Data an prenatal diagnosis (PD) offered to 142 families at high risk and their reproductive decision are submitted. The low rate of families made use of invasive PD is pointed out; the real benefits of ultrasonography as a screening test for detection of fetal anomalies has been recommended.