5 research outputs found
Anomalous behaviour of thermoluminescence from quartz: a case of glow peaks from a Nigerian quartz
Anomalous behaviour displayed by a thermoluminescence (TL) glow peak as radiation dose increases in a Nigerian quartz is presented. The glow curves of the phosphor have four clear glow peaks. The peak temperatures of the first three glow peaks were found to be constant with change in radiation dose at 82, 148 and 200ÂșC for the sample readout at a heating rate of 1ÂșCs[superscript (-1)]. The peak temperature of the fourth peak, which is at around 320ÂșC for a sample irradiated to a dose of 63 Gy and heated at 1ÂșCs[superscript (-1)], displays anomalous behaviour with increase in dose relative to the first three peaks. The temperature at which this peak occurs increases with dose to about 335ÂșC for 177 Gy and then decreases thereafter as dose is further increased. The change is explained on the assumption that the peak may be complex consisting of several overlapping first-order glow peaks each with different TL behaviour
Dependence of NaI(Tl) detector intrinsic efficiency on source-detector distance, energy and off-axis distance: Their implications for radioactivity measurements
Diagnostic exome-based preconception carrier testing in consanguineous couples: results from the first 100 couples in clinical practice
Purpose: Consanguineous couples are at increased risk of being heterozygous for the same autosomal recessive (AR) disorder(s), with a 25% risk of affected offspring as a consequence. Until recently, comprehensive preconception carrier testing (PCT) for AR disorders was unavailable in routine diagnostics. Here we developed and implemented such a test in routine clinical care. Methods: We performed exome sequencing (ES) for 100 consanguineous couples. For each couple, rare variants that could give rise to biallelic variants in offspring were selected. These variants were subsequently filtered against a gene panel consisting of ~2,000 genes associated with known AR disorders (OMIM-based). Remaining variants were classified according to American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) guidelines, after which only likely pathogenic and pathogenic (class IV/V) variants, present in both partners, were reported. Results: In 28 of 100 tested consanguineous couples (28%), likely pathogenic and pathogenic variants not previously known in the couple or their family were reported conferring 25% risk of affected offspring. Conclusion: ES-based PCT provides a powerful diagnostic tool to identify AR disease carrier status in consanguineous couples. Outcomes provided significant reproductive choices for a higher proportion of these couples than previous tests