Coupled calculation of the radiological release and the thermal-hydraulic behaviour of a 3-loop PWR after a SGTR by means of the code RELAP5

To enable a more realistic and accurate calculation of the radiological consequences of a steam generator tube rupture (SGTR), a fission product transport model was developed. As the radiological releases strongly depend on the thermal-hydraulic transient, the model was included in the RELAP5 input decks of the Belgian Nuclear Power Plants. This enables the coupled calculation of the thermal-hydraulic transient and the radiological release. The fission product transport model tracks the concentration of the fission products in the primary circuit, in each of the SGs as well as in the condenser. This leads to a system of six coupled, first order ordinary differential equations with time dependent coefficients. Flashing, scrubbing, atomisation and dry out of the break how are accounted for. Coupling with the thermal-hydraulic calculation and correct modelling of the break position enables an accurate calculation of the mixture level above the break. Pre-and post-accident spiking in the primary circuit are introduced. The transport times in the FW-system and the SG blowdown system are also taken into account, as is the decontaminating effect of the primary make-up system and of the SG blowdown system. Physical input parameters such as the partition coefficients, half life times and spiking coefficients are explicitly introduced so that the same model can be used for iodine, caesium and noble gases. (C) 1997 Elsevier Science S.A

Psychometric Validation of the FACE-Q Craniofacial Module for Facial Nerve Paralysis

Background: Systematic reviews have identified the need for a patient-reported outcome measure for facial nerve paralysis (FNP). The aim of this study was to determine the psychometric properties of FACE-Q Craniofacial module scales when used in a combined sample of children and older adults with FNP. Methods: Data were collected between December 2016 and December 2019. We conducted qualitative interviews with children and adults with FNP. FACE-Q data were collected from patients aged 8 years and older with FNP. Rasch measurement theory analysis was used to examine the reliability and validity of the relevant scales in the FNP sample. Results: Twenty-five patients provided 2052 qualitative codes related to appearance, physical, psychological, and social function. Many patient concerns were common across age. The field-test sample included 235 patients aged 8-81 years. Of the 13 scales examined, all 122 items had ordered thresholds and good item fit to the Rasch model. For 12 scales, person separation index values were ≥0.79 and Cronbach's alpha values were ≥0.82. The 13th scale's reliability values were ≥0.71. Conclusion: The FACE-Q Craniofacial module scales described in this study can be used to collect and compare evidence-based outcome data from children and adults with FNP

Connexin 43 hemichannels contribute to the propagation of apoptotic cell death in a rat C6 glioma cell model

Gap junctions (GJs) have been demonstrated to communicate cell death signals from apoptotic to healthy cells, thereby spatially extending apoptosis. Before being incorporated into GJs, hemichannels (hemi-GJs) are normally closed but recent evidence suggests that they can be opened by various messengers and conditions, thereby forming a pore through which molecules can enter or leave the cell potentially leading to cell death. The aim of this study was to determine the contribution of GJs and hemichannels in the communication of apoptosis toward surrounding cells. We induced apoptosis in C6 glioma cells stably transfected with connexin (Cx)43, with cytochrome C (cytC) using in situ electroporation and found that healthy surrounding cells underwent apoptotic transformation. Work with various cell death markers, wild-type (WT) and Cx43-expressing cells, inhibitors of GJs and/or hemichannels, and Cx43 gene silencing showed that GJs contribute to the spread of apoptosis in a zone next to where apoptosis was triggered whereas hemichannels also promoted cell death beyond this area. Buffering cytoplasmic Ca2+ changes inhibited the spread of apoptosis in both cases. We conclude that Cx43 hemichannels, in concert with their GJ counterparts, play a role in communicating cytC-induced apoptotic cell death messages