Antioxidant activities of sulfated polysaccharides from brown and red seaweeds

The in vitro antioxidant activities of the following six sulfated polysaccharides were investigated: iota, kappa and lambda carrageenans, which are widely used in the food industry, fucoidan (homofucan) from the edible seaweed Fucus vesiculosus and fucans (heterofucans) F0.5 and F1.1 from the seaweed Padina gymnospora. With respect to the inhibition of superoxide radical formation, fucoidan had an IC50 (the half maximal inhibitory concentration) of 0.058 mg·mL−1, while the IC50 for the kappa, iota and lambda carrageenans were 0.112, 0.332 and 0.046 mg·mL−1, respectively. All of the samples had an inhibitory effect on the formation of hydroxyl radicals. The results of peroxidation tests showed that fucoidan had an IC50 of 1.250 mg·mL−1 and that the kappa, iota and lambda carrageenans had an IC50 of 2.753 and 2.338 and 0.323 mg·mL−1, respectively. Fucan fractions showed low antioxidant activity relative to fucoidan. These results clearly indicate the beneficial effect of algal polysaccharides as antioxidants

Capteurs à fibres optiques répartis pour la surveillance du corium en cas d'accident grave de réacteur nucléaire avec percement de la cuve : le projet ANR RSNR DISCOMS

International audienceUne technique de surveillance fondée sur les Capteurs à Fibres Optiques (CFO) répartis (réflectomètres optiques associés à des câbles munis de fibres monomodes rad-hard gainées carbone) est proposée pour la surveillance à distance du corium en cas d’Accident Grave de réacteur nucléaire, avec fusion du coeur et percement de la cuve du réacteur

Capteurs à fibres optiques répartis pour la surveillance du corium en cas d'accident grave de réacteur nucléaire avec percement de la cuve : le projet ANR RSNR DISCOMS

International audienceUne technique de surveillance fondée sur les Capteurs à Fibres Optiques (CFO) répartis (réflectomètres optiques associés à des câbles munis de fibres monomodes rad-hard gainées carbone) est proposée pour la surveillance à distance du corium en cas d’Accident Grave de réacteur nucléaire, avec fusion du coeur et percement de la cuve du réacteur

Capteurs à fibres optiques répartis pour la surveillance du corium en cas d'accident grave de réacteur nucléaire avec percement de la cuve : le projet ANR RSNR DISCOMS

International audienceUne technique de surveillance fondée sur les Capteurs à Fibres Optiques (CFO) répartis (réflectomètres optiques associés à des câbles munis de fibres monomodes rad-hard gainées carbone) est proposée pour la surveillance à distance du corium en cas d’Accident Grave de réacteur nucléaire, avec fusion du coeur et percement de la cuve du réacteur

DISCOMS : Capteurs Répartis pour le surveillance du corium et la sûreté

International audienceThe Fukushima-Daiichi nuclear disaster showed that the need for safety must always prevail. This paper discusses the development of remote monitoring technologies to improve Nuclear Power Plants (NPPs) safety, in operation (Pressurized Water Reactors), under construction (the EPR reactors, i.e. the GEN 3 PWR), or for any other next generations of reactors. At Fukushima, the total loss of electrical power supplies has quickly led most of the instrumentation inoperative and the operator (TEPCO) with no way to monitor the status and the evolution of the accident. To overcome these important drawbacks, advantage can be taken from the considerable potential of distributed sensing technologies based on both "Optical Fiber Sensors" (Raman, Brillouin, and Rayleigh Reflectometries) and long-length "Self Powered Neutron Detectors" (SPNDs). The goal consists in inquiring about the status of the third barrier of confinement and to define possible mitigation strategies in case of severe accident, namely: i) reactor pressure vessel breakthrough and corium relocation outside the vessel, ii) concrete basemat erosion and iii) corium cooling. Such monitoring should consist in "sensing cables" embedded in concrete basemat below the reactor vessel and interrogated from a rear base where operators can work safely. In this context, DISCOMS, which stands for "DIstributed Sensing for COrium Monitoring and Safety", is a five-year project, managed by the French National Research Agency (ANR), dealing with the NPP safety improvement, from normal situation to severe accidents. Monitoring phases include reactor vessel breaching, corium flow, along with post-accidental period (corium cooling ex-vessel). Thus, optical fibers selected for their resistance to ionizing radiations and long length SPNDs, both judiciously deployed within the reactor concrete basemat, and the structures around it, will provide a useful real-time or on-demand monitoring, in normal operation, and more important in accidental and post-accidental situations

Distributed corium monitoring in case of severe accident in a Nuclear Power Plant

article soumis à 26TH INTERNATIONAL CONFERENCE ON OPTICAL FIBRE SENSORS OFS-26 et refusé par la conférenceInternational audienceThe DISCOMS project and its issues, regarding current scientific challenges and potential benefits for nuclear plant safety in case of severe accident with reactor vessel failure, have been discussed. We claim such remote monitoring solution based on state-of-the-art of quasi-distributed OFS and specific long-length SPND should greatly contribute to enhance the quality of real time information during such event, providing first responders and nuclear safety people with direct data concerning both the corium location and the health of the 3rd barrier of confinement. In such context, the monitoring system developed in the scope of the DISCOMS project will enable the crisis teams in charge of handling the emergency situations on NPP to reduce the uncertainties associated to some tools currently used for severe accident mitigation (e.g. computations aids based on calculations of pre-defined Severe Accident scenarios). In particular, after the reactor pressure vessel failure, DISCOMS monitoring will provide the precise and real-time view of the progression front of core melt inside the reactor building basemat or the core catcher (if any). Based on this actual representation of the basemat ablation, the crisis team will be able to optimize the recommended mitigation actions, both for accident management on-site and population protection. In April 18, 2016 the International Atomic Energy Agency records 444 Nuclear Power Plants (NPPs) currently in operation and 64 under construction, located in 31 countries, which means the potential market for the DISCOMS solution is worldwide

Anti-proliferative and apoptotic effects of oleuropein and hydroxytyrosol on human breast cancer MCF-7 cells

Olive oil intake has been shown to induce significant levels of apoptosis in various cancer cells. These anti-cancer properties are thought to be mediated by phenolic compounds present in olive. These beneficial health effects of olive have been attributed, at least in part, to the presence of oleuropein and hydroxytyrosol. In this study, oleuropein and hydroxytyrosol, major phenolic compound of olive oil, was studied for its effects on growth in MCF-7 human breast cancer cells using assays for proliferation (MTT assay), cell viability (Guava ViaCount assay), cell apoptosis, cellcycle (flow cytometry). Oleuropein or hydroxytyrosol decreased cell viability, inhibited cell proliferation, and induced cell apoptosis in MCF-7 cells. Result of MTT assay showed that 200 μg/mL of oleuropein or 50 μg/mL of hydroxytyrosol remarkably reduced cell viability of MCF-7 cells. Oleuropein or hydroxytyrosol decrease of the number of MCF-7 cells by inhibiting the rate of cell proliferation and inducing cell apoptosis. Also hydroxytyrosol and oleuropein exhibited statistically significant block of G1 to S phase transition manifested by the increase of cell number in G0/G1 phase