Sub-terahertz, microwaves and high energy emissions during the December 6, 2006 flare, at 18:40 UT

The presence of a solar burst spectral component with flux density increasing with frequency in the sub-terahertz range, spectrally separated from the well-known microwave spectral component, bring new possibilities to explore the flaring physical processes, both observational and theoretical. The solar event of 6 December 2006, starting at about 18:30 UT, exhibited a particularly well-defined double spectral structure, with the sub-THz spectral component detected at 212 and 405 GHz by SST and microwaves (1-18 GHz) observed by the Owens Valley Solar Array (OVSA). Emissions obtained by instruments in satellites are discussed with emphasis to ultra-violet (UV) obtained by the Transition Region And Coronal Explorer (TRACE), soft X-rays from the Geostationary Operational Environmental Satellites (GOES) and X- and gamma-rays from the Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The sub-THz impulsive component had its closer temporal counterpart only in the higher energy X- and gamma-rays ranges. The spatial positions of the centers of emission at 212 GHz for the first flux enhancement were clearly displaced by more than one arc-minute from positions at the following phases. The observed sub-THz fluxes and burst source plasma parameters were found difficult to be reconciled to a purely thermal emission component. We discuss possible mechanisms to explain the double spectral components at microwaves and in the THz ranges.Comment: Accepted version for publication in Solar Physic

Alveolar echinococcosis in solid organ transplant recipients: a case series from two national cohorts

Alveolar echinococcosis (AE) is a severe parasitic infection caused by the ingestion of Echinococcus multilocularis eggs. While higher incidence and faster evolution have been reported in immunosuppressed patients, no studies have been performed specifically on AE in transplant patients. We searched for all de novo AE cases diagnosed between January 2008 and August 2018 in solid organ transplant (SOT) recipients included in the Swiss Transplant Cohort Study and the FrancEchino Registry. Eight cases were identified (kidney = 5, lung = 2, heart = 1, liver = 0), half of which were asymptomatic at diagnosis. AE diagnosis was difficult due to the low sensitivity (60%) of the standard screening serology (Em2+) and the frequently atypical radiological presentations. Conversely, Echinococcus Western blot retained good diagnostic performances and was positive in all eight cases. Five patients underwent surgery, but complete resection could only be achieved in one case. Moreover, two patients died of peri-operative complications. Albendazole was initiated in seven patients and was well tolerated. Overall, AE regressed in one, stabilized in three, and progressed in one case, and had an overall mortality of 37.5% (3/8 patients). Our data suggest that AE has a higher mortality and a faster clinical course in SOT recipients; they also suggest that the parasitic disease might be due to the reactivation of latent microscopic liver lesions through immune suppression. Western blot serology should be preferred in this population. Finally, surgery should be considered with caution, because of its low success rate and high mortality, and conservative treatment with albendazole is well tolerated

Action de l'oxaliplatine sur le cycle cellulaire et son incorporation dans les lignées cancéreuses humaines

L oxaliplatine (L-OHP) est utilisé pour le traitement du cancer colorectal. Nous avons utilisé quatre lignées tumorales humaines : HT29, MCF7, Hela et A549. L étude de cytotoxicité a montré que les lignées HT29, Hela et MCF7 sont plus sensibles que la lignée A549. L effet principal du L-OHP sur le cycle cellulaire est un arrêt des cellules en G2/M sauf pour la lignée A549, les cellules sont bloquées en G0/G1. Après 12 h de traitement ; seules les lignées MCF7 et Hela ont montré une induction de l apoptose. Après 72 h de traitement l apoptose a été induite pour toutes les lignées. La fixation du platine dans les compartiments cellulaires augmente avec le temps.Les études pharmacologiques que nous avons présentées suggèrent que la perfusion de l oxaliplatine doit être prolongée au moins 6 h plutôt que 2 h, pour permettre au médicament de mieux pénétrer la tumeur, de modifier efficacement le cycle cellulaire et d induire l apoptose. Les études cliniques sont en faveur de cette hypothèse.L oxaliplatin (L-OHP) is used for treatment of colorectal cancer. We have used four human cancer cell lines: HT29, MCF7, Hela and A549. The study of cytotoxicity has showed that HT29, MCF7 and Hela are more sensitive to treatment than A549.The principal effect of L-OHP on the cell cycle is an arrest of cells in G2/M phase except for A549, which is arrested in G0/G1.After 12 h of treatment, only MCF7 and Hela have showed induction of apoptosis. After 72 h of treatment apoptosis was induced for all cell lines. The accumulation of platinum in all cellular compartments increased with time.The pharmacological studies that we have presented suggest that L-OHP perfusion should be extended at least 6 h than 2 h, in order that drug penetrate better the tumour, to modify effectively the cell cycle and induce apoptosis. The recent clinical studies are in favour of this hypothesis.PARIS-BIUP (751062107) / SudocSudocFranceF

Synthesis, structural characterization and biological activity against several human tumor cell lines of four rhenium(I) diseleno-ethers complexes: Re(CO)3Cl(PhSe(CH2)2SePh), Re(CO)3Cl(PhSe(CH2)3SePh), Re(CO)3Cl(HO2C–CH2Se(CH2)2SeCH2–CO2H) and Re(CO)3Cl(HO2C–CH2Se(CH2)3SeCH2–CO2H)

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PbS-based active photon cages

11-15 mai 2015International audienceno abstrac