Red-emitting liquid and plastic scintillators with nanosecond time response

International audienceDue to the extreme experimental conditions encountered, the Laser Megajoule facility (LMJ) needs to develop and characterize new organic scintillators with unseen features: a fast decay time, in the order of one nanosecond with almost no afterglow, and an emission wavelength in the red region, typically more than 600 nm. Thus, various compositions have been evaluated, prepared and tested. The materials are composed of a matrix (either liquid or plastic) embedding two fluorophores and a light quencher. Time-Correlated Single Photon Counting was used to assess the main criteria of the materials, which is their photoluminescence decay. In the liquid state, ultra-fast materials were successfully prepared. One liquid scintillator formulation showed the following characteristics: an emission wavelength > 600 nm, a mean decay time of 0.84 ns with a FWHM pulse width of 1.92 ns. In the plastic state the preparation was less straightforward. A plastic scintillator with emission wavelength > 600 nm, a decay time < 7 ns with a FWHM of 8.60 ns was obtained. We have verified that the best plastic sample does not present any afterglow. A light yield around 200 ph/MeV has been estimated from relative radioluminescence measurements, this value being around 4 times lower than the BC-422Q 2%, quenched plastic scintillator

Light recycling in LED-pumped Ce:YAG luminescent concentrators

International audienceWe report the development of a high-brightness, high-power Ce:YAG luminescent concentrator pumped by 2240 blue LEDs in quasi-continuous wave operation (10 µs, 10 Hz). Using light confinement and recycling in the three space dimensions, the parallelepiped (1mm×14×mm×200mm) Ce:YAG emits a power of 145 W from a square output surface (1 × 1mm 2) corresponding to a brightness of 4.6 kW/cm 2 /sr. This broadband yellow source has a unique combination of luminous flux (7.6 10 4 lm) and brightness (2.4 10 4 cd/mm 2) and overcomes many other visible incoherent sources by one order of magnitude. This paper also proposes a deep understanding of the performance drop compared to a linear behavior when the pump power increases. Despite excited state absorption was unexpected for this low doped Ce:YAG pumped at a low irradiance level, we demonstrated that it affects the performance by tripling the losses in the concentrator. This effect is particularly important for small output surfaces corresponding to strong light recycling in the concentrator and to average travel distances inside the medium reaching meters

Systematic Comparison of Uremic Toxin Removal Using Different Hemodialysis Modes: A Single-Center Crossover Prospective Observational Study

Many hypotheses could explain the mortality decrease observed using hemodiafiltration, such as reduction of intradialytic hypotension and more efficient toxin removal. We led a systematic analysis of representative uremic toxin removal with hemodialysis (HD), online postdilution hemodiafiltration (postHDF) and online predilution hemodiafiltration (preHDF), in a single-center crossover and prospective observational study. The primary outcome was the reduction ratio of uremic toxins of the three categories defined by the Eutox group. Twenty-six patients were treated by those three techniques of extra renal epuration. Mean Kt/Vurea was not different between the treatment methods. Mean reduction ratio of beta2microglobulin was significantly higher for both HDF treatments than for HD (p &lt; 0.001). Myoglobin, kappa, and lambda free light chain reduction ratio was significantly different between the modes: 37.75 &plusmn; 11.95%, 45.31 &plusmn; 11% and 61.22 &plusmn; 10.56%/57.21 &plusmn; 12.5%, 63.53 &plusmn; 7.93%, and 68.40 &plusmn; 11.79%/29.12 &plusmn; 8.44%, 34.73 &plusmn; 9.01%, and 45.55 &plusmn; 12.31% HD, preHDF, and postHDF, respectively (p &lt; 0.001). Mean protein-bound solutes reduction ratio was not different between the different treatments except for PCS with a higher reduction ratio during HDF treatments. Mean albumin loss was always less than 2 g. HDF improved removal of middle molecules but had no effect on indoles concentration without any difference between synthetic dialysis membranes

Systematic Comparison of Uremic Toxin Removal Using Different Hemodialysis Modes: A Single-Center Crossover Prospective Observational Study

Many hypotheses could explain the mortality decrease observed using hemodiafiltration, such as reduction of intradialytic hypotension and more efficient toxin removal. We led a systematic analysis of representative uremic toxin removal with hemodialysis (HD), online postdilution hemodiafiltration (postHDF) and online predilution hemodiafiltration (preHDF), in a single-center crossover and prospective observational study. The primary outcome was the reduction ratio of uremic toxins of the three categories defined by the Eutox group. Twenty-six patients were treated by those three techniques of extra renal epuration. Mean Kt/Vurea was not different between the treatment methods. Mean reduction ratio of beta2microglobulin was significantly higher for both HDF treatments than for HD (p p < 0.001). Mean protein-bound solutes reduction ratio was not different between the different treatments except for PCS with a higher reduction ratio during HDF treatments. Mean albumin loss was always less than 2 g. HDF improved removal of middle molecules but had no effect on indoles concentration without any difference between synthetic dialysis membranes

Genome project of the meat born lactic acid bacterium Lactobacillus sakei 23K: understanding bacterial adaptation to meat and paving the way to the development of biopreservative cultures

International audienc

La séquence complète du génome de la bactérie de la viande Lactobacillus sakei

National audienc

The complete genome sequence of the meat-borne lactic acid bacterium Lactobacillus sakei 23K

The sequence reported in this paper has been deposited in the EMBL database as Accession No. CR936503. The annotated genome sequence and the relevant AGMIAL database (Genome navigator, BLAST server and Metabolic comparison) are available at http://migale.jouy.inra.fr/sakei/.International audienceLactobacillus sakei is a psychrotrophic lactic acid bacterium found naturally on fresh meat and fish. This microorganism is widely used in the manufacture of fermented meats and has biotechnological potential in biopreservation and food safety. We have explored the 1,884,661-base-pair (bp) circular chromosome of strain 23K encoding 1,883 predicted genes. Genome sequencing revealed a specialized metabolic repertoire, including purine nucleoside scavenging that may contribute to an ability to successfully compete on raw meat products. Many genes appear responsible for robustness during the rigors of food processing – particularly resilience against changing redox and oxygen levels. Genes potentially responsible for biofilm formation and cellular aggregation that may assist the organism to colonize meat surfaces were also identified. This genome project is an initial step for investigating new biotechnological approaches to meat and fish processing and for exploring fundamental aspects of bacterial adaptation to these specific environments

French recommendations for the management of systemic necrotizing vasculitides (polyarteritis nodosa and ANCA-associated vasculitides)

International audienceSystemic necrotizing vasculitis comprises a group of diseases resembling polyarteritis nodosa and anti-neutrophil cytoplasmic antibody-associated vasculitis (ANCA): granulomatosis with polyangiitis, eosinophilic granulomatosis with polyangiitis, and microscopic polyangiitis. The definitive diagnosis is made in cooperation with a reference center for autoimmune diseases and rare systemic diseases or a competency center. The management goals are: to obtain remission and, in the long term, healing; to reduce the risk of relapses; to limit and reduce the sequelae linked to the disease; to limit the side effects and the sequelae linked to the treatments; to improve or at least maintain the best possible quality of life; and to maintain socio-professional integration and/or allow a rapid return to school and/or professional activity. Information and therapeutic education of the patients and those around them are an integral part of the care. All health professionals and patients should be informed of the existence of patient associations. The treatment of vasculitis is based on variable combinations of glucocorticoids and immunosuppressants, chosen and adapted according to the disease concerned, the severity and/or extent of the disease, and the underlying factors (age, kidney function, etc.). Follow-up clinical and paraclinical examinations must be carried out regularly to clarify the progression of the disease, detect and manage treatment failures and possible relapses early on, and limit sequelae and complications (early then late) related to the disease or treatment. A distinction is made between the induction therapy, lasting approximately 3-6 months and aimed at putting the disease into remission, and the maintenance treatment, lasting 12-48 months, or even longer. The role of the increase or testing positive again for ANCA as a predictor of a relapse, which has long been controversial, now seems to have greater consensus: Anti-myeloperoxidase ANCAs are less often associated with a relapse of vasculitis than anti-PR3 ANCA