Radiation Monitoring in Mixed Environments at CERN: from the IRRAD6 Facility to the LHC Experiments

RadFET and p-i-n diode semiconductor dosimeters from different manufacturers will be used for radiation monitoring at the Experiments of the CERN LHC accelerator. In this work these sensors were exposed over three months in the CERN-IRRAD6 facility that provides mixed high-energy particles at low rates. The aim was to validate the operation of such sensors in a radiation field where the conditions are close to the ones expected inside full working LHC particle detectors. The results of this long-term irradiation campaign are presented, discussed and compared with measurements by other dosimetric means as well as Monte Carlo simulations. Finally, the integration of several dosimetric devices in one sensor carrier is also presented

MOSFET dosimetry for microbeam radiation therapy at the European Synchrotron Radiation Facility

Preclinical experiments are carried out with ~20–30 μm wide, ~10 mm high parallel microbeams of hard, broad-‘‘white’’-spectrum x rays (~50–600 keV) to investigate microbeam radiation therapy (MRT) of brain tumors in infants for whom other kinds of radiotherapy are inadequate and/or unsafe. Novel physical microdosimetry (implemented with MOSFET chips in the ‘‘edge-on’’ mode) and Monte Carlo computer-simulated dosimetry are described here for selected points in the peak and valley regions of a microbeam-irradiated tissue-equivalent phantom. Such microbeam irradiation causes minimal damage to normal tissues, possible because of rapid repair of their microscopic lesions. Radiation damage from an array of parallel microbeams tends to correlate with the range of peak-valley dose ratios (PVDR). This paper summarizes comparisons of our dosimetric MOSFET measurements with Monte Carlo calculations. Peak doses at depths \u3c22 mm are 18% less than Monte Carlo values, whereas those depths \u3e22 mm and valley doses at all depths investigated (2 mm–62 mm) are within 2–13% of the Monte Carlo values. These results lend credence to the use of MOSFET detector systems in edge-on mode for microplanar irradiation dosimetry

Association between maternal nutritional status in pregnancy and offspring cognitive function in childhood and adolescence; a systematic review

Background The mother is the only source of nutrition for fetal growth including brain development. Maternal nutritional status (anthropometry, macro- and micro-nutrients) before and/or during pregnancy is therefore a potential predictor of offspring cognitive function. The relationship of maternal nutrition to offspring cognitive function is unclear. This review aims to assess existing evidence linking maternal nutritional status with offspring cognitive function. Methods Exposures considered were maternal BMI, height and weight, micronutrient status (vitamins D, B12, folate and iron) and macronutrient intakes (carbohydrate, protein and fat). The outcome was any measure of cognitive function in children aged <18 years. We considered observational studies and trials with allocation groups that differed by single nutrients. We searched Medline/PubMed and the Cochrane Library databases and reference lists of retrieved literature. Two reviewers independently extracted data from relevant articles. We used methods recommended by the Centre for Reviews and Dissemination, University of York and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. Results Of 16,143 articles identified, 38 met inclusion criteria. Most studies were observational, and from high-income settings. There were few randomized controlled trials. There was consistent evidence linking maternal obesity with lower cognitive function in children; low maternal BMI has been inadequately studied. Among three studies of maternal vitamin D status, two showed lower cognitive function in children of deficient mothers. One trial of folic acid supplementation showed no effects on the children’s cognitive function and evidence from 13 observational studies was mixed. Among seven studies of maternal vitamin B12 status, most showed no association, though two studies in highly deficient populations suggested a possible effect. Four out of six observational studies and two trials (including one in an Iron deficient population) found no association of maternal iron status with offspring cognitive function. One trial of maternal carbohydrate/protein supplementation showed no effects on offspring cognitive function. Conclusions Current evidence that maternal nutritional status during pregnancy as defined by BMI, single micronutrient studies, or macronutrient intakes influences offspring cognitive function is inconclusive. There is a need for more trials especially in populations with high rates of maternal undernutrition. Systematic review registration Registered in PROSPERO CRD42013005702

Radiation monitoring in mixed environments at CERN: from the IRRAD6 facility to the LHC experiments

RadFET and p-i-n diode semiconductor dosimeters from different manufacturers will be used for radiation monitoring at the Experiments of the CERN LHC accelerator. In this work these sensors were exposed over three months in the CERN-IRRAD6 facility that provides mixed high-energy particles at low rates. The aim was to validate the operation of such sensors in a radiation field where the conditions are close to the ones expected inside full working LHC particle detectors. The results of this long-term irradiation campaign are presented, discussed and compared with measurements by other dosimetric means as well as Monte Carlo simulations. Finally, the integration of several dosimetric devices in one sensor carrier is also presented