Anomaly in the dielectric response at the charge orbital ordering transition of crystalline Pr0.67Ca0.33MnO3

The complex impedance of a Pr0.67Ca0.33MnO3 crystal has been measured. The frequency dependence is studied for a wide range of temperatures (50K-403K) and is found to be characteristic of relaxation process with a single Debye time relaxation constant, which is interpreted as a dielectric constant of the material. A strong peak is observed in this dielectric constant (up to two millions) at the charge ordering transition suggesting an interpretation in terms of ordering of electric dipoles at TCO or in term of phase separation. Comparison with Pr0.63Ca0.37MnO3 - in which the phase separation is much smaller and the peak in the dielectric constant is absent - suggests an interpretation in term of phase separation between insulating and metallic states.Comment: pdf fil

A mediastinal seminoma

peer reviewe

Gastric antral vascular ectasia syndrome : clinical and endoscopic presentation and endoscopic treatment

Nous rapportons une série de dix patients chez lesquels un «syndrome d'Ectasies Vasculaires Antrales » a été découvert lors d'un bilan endoscopique. Sept patients présentaient une anémie ferriprive chronique et ont bénéficié d'un traitement endoscopique. Les aspects clinique, physiopathologique, histologique et endoscopique sont discutés à la lumière de la littérature

Comprehensive mapping of immune tolerance yields a regulatory TNF receptor 2 signature in a murine model of successful Fel d 1-specific immunotherapy using high-dose CpG adjuvant.

Background: The prevalence of allergy to cat is expanding worldwide. Allergen-specific immunotherapy (AIT) has advantages over symptomatic pharmacotherapy and promises long-lasting disease control in allergic patients. However, there is still a need to improve cat AIT regarding efficacy, safety, and adherence to the treatment. Here, we aim to boost immune tolerance to the major cat allergen Fel d 1 by increasing the anti-inflammatory activity of AIT with the established immunomodulatory adjuvant CpG, but at a higher dose than previously used in AIT. Methods: Together with CpG, we used endotoxin-free Fel d 1 as therapeutic allergen throughout the study in a BALB/c model of allergy to Fel d 1, thus mimicking the conditions of human AIT trials. Multidimensional immune phenotyping including mass cytometry (CyTOF) was applied to analyze AIT-specific immune signatures. Results: We show that AIT with high-dose CpG in combination with endotoxin-free Fel d 1 reverts all major hallmarks of allergy. High-dimensional CyTOF analysis of the immune cell signatures initiating and sustaining the AIT effect indicates the simultaneous engagement of both, the pDC-Treg and B-cell axis, with the emergence of a systemic GATA3+ FoxP3hi biTreg population. The regulatory immune signature also suggests the involvement of the anti-inflammatory TNF/TNFR2 signaling cascade in NK and B cells at an early stage and in Tregs later during AIT. Conclusion: Our results highlight the potential of CpG adjuvant in a novel formulation to be further exploited for inducing allergen-specific tolerance in patients with cat allergy or other allergic diseases

STAMS : New tools for monitoring flooded and nonflooded mine shaft

International audienceIn European coalmines, there are many unequipped, abandoned shafts (in Poland, Germany, France, Spain, UK and other countries) in which the long term stability is a cause of concern. The need for continuous assessment and monitoring of the stability of abandoned shafts present a real challenge particularly for deep shafts. The European STAMS research project (Long term STability Assessment and Monitoring of flooded Shafts), subsidized by the Research Fund for Coal and Steel programme (RFCS), is addressing this issue. The objective of the STAMS project is to implement Periodic Inspection Modules, and to design permanently installed monitoring systems, to achieve periodic and long term continuous monitoring and condition assessment of flooded mine shafts. The project proposes solutions to monitor and to assess the stability and the conditions of flooded shafts, including the non flooded portions of partially flooded shafts, for long periods of time. The Multi functional Monitoring Module is able to make periodic measurements in order to assess the stability of a flooded shaft. The Ultrasonic Inspection Module allows the detection of lining deformations with high precision between periodic inspections of shafts. In addition to monitoring, a modelling approach has been developed to assess the long term stability of shafts during and after flooding by coupling the hydro mechanical behaviour with the chemical reactions which occur between the mine water and the shaft lining components. A database of the flooded shafts has been established. Laboratory and trials tests are carried out by the partners of the project to check the tools and to test them under real conditions. This paper presents and describes the developed modules and the first obtained results