Neutronic characterization of the MEGAPIE target

The MEGAPIE project aimed to design, build and operate a liquid metal spallation neutron target of about 1 MW beam power in the SINQ facility at the Paul Scherrer Institut (Villigen, Switzerland). This project is an important step in the roadmap towards the demonstration of the accelerator driven system (ADS) concept and high power liquid metal targets in general. Following the design phase, an experimental program was defined to provide a complete characterization of the facility by performing a “mapping” of the neutron flux at different points, from the center of the target to the beam lines. The neutronic performance of the target was studied using different experimental techniques with the goals of validating the Monte Carlo codes used in the design of the target; additionally, the performance was compared with the solid lead targets used before and after the MEGAPIE experiment.     

Deep defect determination by the constant photocurrent method (CPM) in annealed or light soaked amorphous hydrogenated silicon (a-Si:H)

We present systematic measurements of CPM on two independent series of slightly phosphorous and boron doped films. For “n-type” samples of both series, the CPM deep defect absorption is proportional to the square root of the gas dopant ratio. For these samples we discuss the influence of Fermi level on the CPM spectra. For slightly “p-type” samples, CPM deep defect absorption as evaluated by CPM becomes higher than the corresponding PDS-values. This fundamental problem can be traced back to the violation of two basic conditions necessary for a correct evaluation of the absorption from CPM measurements: (1) the power law exponent γ (Rose factor) of the photoconductivity must be spectrally independent, and (2) the generation rate G, which corresponds to the CPM photocurrent, also has to be spectrally independent. Further, we compare the annealed and the “saturated” light soaked states of selected slightly doped samples and an undoped sample: the variations in the CPM deep defect absorption and in photoconductivity due to light-soaking are discussed.     

A novel method for elimination of aflatoxin M1 in milk using Lactobacillus rhamnosus GG biofilm

This study aimed to develop a new method for detoxification of milk from aflatoxin M1 (AFM1) by using Lactobacillus rhamnosus GG biofilm. After inoculation of milk contaminated with AFM1 into L. rhamnosus GG biofilm, the unbound AFM1 was extracted and quantified by HPLC. The stability of the formed AFM1/biofilm complex using different AFM1 contamination levels of milk was also studied. We found that the percentages of bound AFM1 by L. rhamnosus GG biofilm reached up to 60.74%. While no significant difference in milk proteins content was observed after AFM1 binding, some changes in total dry matter and fat content were noticed.     

Experimental investigation in the TOSQAN facility of heat and mass transfers in a spray for containment application

TOSQAN is an experimental program undertaken by the Institut de Radioprotection et de Sûreté Nucléaire (IRSN) in order to perform thermal hydraulic containment studies. The TOSQAN facility is a large enclosure devoted to simulate typical accidental thermal hydraulic flow conditions in nuclear-pressurized water reactor (PWR) containment. The TOSQAN facility which is highly instrumented with non-intrusive optical diagnostics is particularly adapted to nuclear safety CFD code validation. The present work is devoted to studying the interaction of a water spray injection used as a mitigation means in order to reduce the gas pressure and temperature in the containment, to produce gases mixing and washout of fission products. In order to have a better understanding of heat and mass transfers between spray droplets and the gas mixture, and to analyze mixing effects due to spray activation, we perform detailed characterization of the two-phase flow.     

Finite difference transmission line model for the design of safe multi-section cables in MRI

Magnetic Resonance Materials in Physics, Biology and Medicine - To show the relevance of a simple finite difference transmission line model to help design safe implanted cables in 1.5T MRI’s...     

Mineralocorticoid hormone receptor and the epithelial sodium channel in a human leukemic cell line

A Cell extract from the HEL (human erythroblastic leukemia) cell line was positive for both the epithelial sodium channel (ENaC) and the mineralocorticoid receptor (MCR) as glycosylated 82-84 kDa bands, and a single 102 kDa band, respectively, in Western blots using polyclonal antibodies raised against these proteins. The immunofluorescent labeling of the MCR in all cell lines showed a nucleocytoplasmic localization of the receptor whereas the ENaC was exclusively membrane-bound. These results were confirmed by confocal microscopy. The expression of the MCR in HEL cells was evident as a predicted band of 843 bp (234 amino acids) after total RNA from HEL cells had been reverse transcribed and then amplified by PCR; the ENaC was similarly evident as a predicted band of 520 bp. In both cases, near 100% identity was observed between the deduced amino acid sequences of the PCR products and those from known human sources. The multiplication of HEL cells was influenced by antagonists (RU 26752, ZK 91587) targeted for specificity to the MCR and this was reversed by the natural hormone aldosterone. These steroids also provoked chromatin condensation in the HEL population.     

Interaction between a coke and a tar. 2. Limit of tar penetration in coke porosity

The limit of penetration of a given coal-tar pitch into two cokes during mixing of the coke and liquid tar has been studied. It was shown that tar penetration is limited by compression of gas occluded in pores. Mercury porosimetry of cokes and pyrolysed coke-tar mixtures as well as micrographs of cokes impregnated with tar allow one to estimate the limiting pore diameter of tar penetration into coke at ca. 6 μm for the system considered.     

Myelinosome Organelles in the Retina of R6/1 Huntington Disease (HD) Mice: Ubiquitous Distribution and Possible Role in Disease Spreading

Visual deficit is one of the complications of Huntington disease (HD), a fatal neurological disorder caused by CAG trinucleotide expansions in the Huntingtin gene, leading to the production of mutant Huntingtin (mHTT) protein. Transgenic HD R6/1 mice expressing human HTT exon1 with 115 CAG repeats recapitulate major features of the human pathology and exhibit a degeneration of the retina. Our aim was to gain insight into the ultrastructure of the pathological HD R6/1 retina by electron microscopy (EM). We show that the HD R6/1 retina is enriched with unusual organelles myelinosomes, produced by retinal neurons and glia. Myelinosomes are present in all nuclear and plexiform layers, in the synaptic terminals of photoreceptors, in the processes of retinal neurons and glial cells, and in the subretinal space. In vitro study shows that myelinosomes secreted by human retinal glial Müller MIO-M1 cells transfected with EGFP-mHTT-exon1 carry EGFP-mHTT-exon1 protein, as revealed by immuno-EM and Western-blotting. Myelinosomes loaded with mHTT-exon1 are incorporated by naive neuronal/neuroblastoma SH-SY5Y cells. This results in the emergence of mHTT-exon1 in recipient cells. This process is blocked by membrane fusion inhibitor MDL 28170. Conclusion: Incorporation of myelinosomes carrying mHTT-exon1 in recipient cells may contribute to HD spreading in the retina. Exploring ocular fluids for myelinosome presence could bring an additional biomarker for HD diagnostics.     

Inhibitory activity of plumbagin produced by Drosera intermedia on food spoilage fungi

BACKGROUND: The aim of this study was to investigate the growth‐inhibiting efficacy of Drosera intermedia extracts (water, methanol and n‐hexane) against four food spoilage yeasts and five filamentous fungi strains responsible for food deterioration and associated with mycotoxin production, in order to identify potential antimycotic agents. RESULTS: The n‐hexane extract showed a broad activity spectrum against all tested microorganisms, followed, in activity, by the methanol and water extracts. The major component of the n‐hexane extract was purified using a solid‐phase extraction column and identified as plumbagin. Results show that high‐purity plumbagin can be produced from D. intermedia cultures following a simple and effective isolation procedure. A sample of purified plumbagin was tested against the same panel of microorganisms and high growth‐inhibiting capacity was observed. Minimum inhibitory concentrations less than 2 µg mL^?1 were obtained against the filamentous fungi. In the case of the species Aspergillus fumigatus, A. niger and A. flavus , activities comparable to miconazole were obtained. CONCLUSION: The results obtained provided evidence of the antimycotic activity of plumbagin, suggesting that D. intermedia could be the source of an interesting compound for the food industry as an alternative to preservatives. Copyright © 2011 Society of Chemical Industry