Neonatal Screening for Cystic Fibrosis in Hungary—First-Year Experiences

The aim of this study is to evaluate the strategy of the cystic fibrosis newborn screening (CFNBS) programme in Hungary based on the results of the first year of screening. A combined immunoreactive trypsinogen (IRT) and pancreatitis-associated protein (PAP) CFNBS protocol (IRT/IRT×PAP/IRT) was applied with an IRT-dependent safety net (SN). Out of 88,400 newborns, 256 were tested screen-positive. Fourteen cystic fibrosis (CF) and two cystic fibrosis-positive inconclusive diagnosis (CFSPID) cases were confirmed from the screen-positive cases, and two false-negative cases were diagnosed later. Based on the obtained results, a sensitivity of 88% and a positive predictive value (PPV) of 5.9% were calculated. Following the recognition of false-negative cases, the calculation method of the age-dependent cut-off was changed. In purely biochemical CFNBS protocols, a small protocol change, even after a short period, can have a significant positive impact on the performance. CFNBS should be monitored continuously in order to fine-tune the screening strategy and define the best local practices

Crossover from ionic hopping to nearly constant loss in the fast ionic conductor Li_(0.18)La_(0.61)TiO_(3)

Electrical conductivity measurements of the fast ionic conductor Li_(0.18)La_(0.61)TiO_(3) have been conducted at temperatures ranging from 8 to 300 K and frequencies between 20 Hz and 5 MHz. A detailed analysis of the ac conductivity shows the existence of a crossover between two different regimes. At high temperatures and/or low frequencies correlated ion hopping is responsible for a power-law frequency dependent and thermally activated ac conductivity. On the other hand, at sufficiently low temperatures and/or high frequencies, the ions do not have enough thermal energy or time to hop between neighboring sites, and remain caged. The ac conductivity is then characterized by a linear frequency dependence (i.e., the equivalent of a nearly constant loss) and by a weak exponential temperature dependence of the form exp(T/T_(0)). A crossover between the two regimes is found, which is thermally activated with an activation energy E50.17 eV, significantly lower than that observed for the dc conductivity, E_(δ)50.4 eV. From this result, it is shown that the so-called "augmented Jonscher expression" fails to describe the ac conductivity in the whole frequency and temperature ranges. All these findings suggest that the nearly constant loss originates from electrical loss occurring during the time regime while the ion is still confined in the potential-energy minimum. Further, it is proposed that the loss mechanism involves some type of process where the potential-energy minimum relaxes in time on a time scale much shorter than the ionic hopping time scale. At longer times, as soon as the ion has significant probability of being thermally activated out of the potential well, the nearly constant loss terminates and correlated ion hopping becomes the only contribution to the ac conductivity