Radio-oxidation ageing of XLPE containing different additives and fillers: effect on the gases emission and consumption

International audienceIn the lifetime extension of nuclear power plants (NPPs) context, aging of electric cables has to be very well understood in order to predict their end-of-life and thus to replace them on time. Therefore, evaluation and understanding of the ageing mechanism of the cable insulating material is mandatory under conditions as close as possible of those encountered in NPPs. In this context, different formulated crosslinked polyethylenes (XLPE)—one of the polymers used nowadays to manufacture the insulator layer—have been irradiated under oxidative conditions, at two different dose rates and at different aging doses. Gases emitted and consumed from the irradiated polymers were quantified to identify the primary processes happening in the materials and thus the interactions involved between the different molecules composing the formulated polymer

Sterilization Induced Changes in Polypropylene-Based Ffp2 Masks

International audienceIn the context of the SARS-CoV2 pandemic and because of the surgical and FFP2 mask (equivalent to the American N95 masks) shortages, studies on efficient sterilization protocols were initiated. As sterilization using irradiation is commonly used in the medical field, this method was among those that were evaluated. In this work, we tested irradiation under vacuum and under air (under both γ-rays and e-beams), but also, for acceptance purposes, undertook washing prior to the e-beam irradiation sterilization process. This article deals with the modifications induced by the sterilization processes at the molecular and the macromolecular scales on an FFP2 mask. Fourier transform infrared spectroscopy in attenuated total reflectance mode, size-exclusion chromatography and thermal-desorption-gas chromatography-mass spectrometry were used to characterize possible damage to the materials. It appeared that the modifications induced by the different sterilization processes under vacuum were relatively tenuous and became more significant when irradiation was performed using γ-rays under air

Optimal KI Prophylactic Dose Determination for Thyroid Radiation Protection After a Single Administration in Adult Rats

A dose–response study was performed in adult rats to select an optimal stable potassium iodide (KI) dose which could be implemented in repeated prophylaxis, in case of prolonged exposure to radioactive iodine. Increasing doses of KI were given orally to rats 1 hour before internal exposure simulated by I-125 injection. I-125 incorporation in the thyroid was measured by γ-spectrometry, and KI protection effect was modeled by pharmacological functions. The measurement method by inductively coupled plasma mass spectrometry previously developed for the quantification of stable iodine in urine was adapted to correlate KI effect with its distribution in the thyroid. More than 75% blockade of iodine I-125 incorporation in the thyroid was achieved for KI single doses above 0.5 to 0.7 mg/kg. Stable iodine content in the thyroid 24 hours after KI administration displayed a biphasic response, with a maximum level for a dose around 1 mg/kg. Besides, the urinary excretion of stable iodine is described by a sigmoid function. The change in the rate of iodine excretion for doses above 1 mg/kg KI suggests a body overload in iodine and corroborates a possible saturation of the thyroid. The results show that 1 mg/kg KI could be regarded as an optimal dose for thyroid protection

CLN3 deficiency leads to neurological and metabolic perturbations during early development.

peer reviewedJuvenile neuronal ceroid lipofuscinosis (or Batten disease) is an autosomal recessive, rare neurodegenerative disorder that affects mainly children above the age of 5 yr and is most commonly caused by mutations in the highly conserved CLN3 gene. Here, we generated cln3 morphants and stable mutant lines in zebrafish. Although neither morphant nor mutant cln3 larvae showed any obvious developmental or morphological defects, behavioral phenotyping of the mutant larvae revealed hyposensitivity to abrupt light changes and hypersensitivity to pro-convulsive drugs. Importantly, in-depth metabolomics and lipidomics analyses revealed significant accumulation of several glycerophosphodiesters (GPDs) and cholesteryl esters, and a global decrease in bis(monoacylglycero)phosphate species, two of which (GPDs and bis(monoacylglycero)phosphates) were previously proposed as potential biomarkers for CLN3 disease based on independent studies in other organisms. We could also demonstrate GPD accumulation in human-induced pluripotent stem cell-derived cerebral organoids carrying a pathogenic variant for CLN3 Our models revealed that GPDs accumulate at very early stages of life in the absence of functional CLN3 and highlight glycerophosphoinositol and BMP as promising biomarker candidates for pre-symptomatic CLN3 disease

CLN3 deficiency leads to neurological and metabolic perturbations during early development

AbstractJuvenile Neuronal Ceroid Lipofuscinosis (or Batten disease) is an autosomal recessive, rare neurodegenerative disorder that affects mainly children above the age of 5 years and is most commonly caused by mutations in the highly conservedCLN3gene. Here, we generatedcln3morphants and stable mutant lines in zebrafish. Although neither morphant nor mutantcln3larvae showed any obvious developmental or morphological defects, behavioral phenotyping of the mutant larvae revealed higher basal activity, hyposensitivity to abrupt light changes and hypersensitivity to pro-convulsive drugs. Importantly, in-depth metabolomics and lipidomics analyses revealed significant accumulation of several glycerophosphodiesters (GPDs) and a global decrease of bis(monoacylglycero)phosphate (BMP) species, two classes of molecules previously proposed as potential biomarkers forCLN3disease based on independent studies in other organisms. We could also demonstrate GPD accumulation in human-induced pluripotent stem cell-derived cerebral organoids carrying a pathogenic variant forCLN3. Our models revealed that GPDs accumulate at very early stages of life in the absence of functional CLN3 and highlight glycerophosphoinositol and BMP as promising biomarker candidates for pre-symptomaticCLN3disease

Identification of a transient state during the acquisition of temozolomide resistance in glioblastoma

International audienceDrug resistance limits the therapeutic efficacy in cancers and leads to tumor recurrence through ill-defined mechanisms. Glioblastoma (GBM) are the deadliest brain tumors in adults. GBM, at diagnosis or after treatment, are resistant to temozolomide (TMZ), the standard chemotherapy. To better understand the acquisition of this resistance, we performed a longitudinal study, using a combination of mathematical models, RNA sequencing, single cell analyses, functional and drug assays in a human glioma cell line (U251). After an initial response characterized by cell death induction, cells entered a transient state defined by slow growth, a distinct morphology and a shift of metabolism. Specific genes expression associated to this population revealed chromatin remodeling. Indeed, the histone deacetylase inhibitor trichostatin (TSA), specifically eliminated this population and thus prevented the appearance of fast growing TMZ-resistant cells. In conclusion, we have identified in glioblastoma a population with tolerant-like features, which could constitute a therapeutic target

The properties of hot household hygroscopic materials and their potential use for non-medical facemask decontamination

The wide use of facemasks through the population to prevent SARS-CoV-2 virus transmission, and its resulting mis- or even non-decontamination are challenging the management of the epidemic at a large scale. As a complement to machine-wash that wastes significant amount of water and energy, hot hygroscopic materials could be used to decontaminate non-medical facemasks in household settings. We report the inactivation of a viral load on a facial mask for an exposure of 15 minutes, with the combined effect of heat and humidity under a decaying pattern suggesting straight-forward general public deployment towards a reliable implementation by the population