Hyper-IgG4 disease: report and characterisation of a new disease

BACKGROUND: We highlight a chronic inflammatory disease we call 'hyper-IgG4 disease', which has many synonyms depending on the organ involved, the country of origin and the year of the report. It is characterized histologically by a lymphoplasmacytic inflammation with IgG4-positive cells and exuberant fibrosis, which leaves dense fibrosis on resolution. A typical example is idiopathic retroperitoneal fibrosis, but the initial report in 2001 was of sclerosing pancreatitis. METHODS: We report an index case with fever and severe systemic disease. We have also reviewed the histology of 11 further patients with idiopathic retroperitoneal fibrosis for evidence of IgG4-expressing plasma cells, and examined a wide range of other inflammatory conditions and fibrotic diseases as organ-specific controls. We have reviewed the published literature for disease associations with idiopathic, systemic fibrosing conditions and the synonyms: pseudotumour, myofibroblastic tumour, plasma cell granuloma, systemic fibrosis, xanthofibrogranulomatosis, and multifocal fibrosclerosis. RESULTS: Histology from all 12 patients showed, to varying degrees, fibrosis, intense inflammatory cell infiltration with lymphocytes, plasma cells, scattered neutrophils, and sometimes eosinophilic aggregates, with venulitis and obliterative arteritis. The majority of lymphocytes were T cells that expressed CD8 and CD4, with scattered B-cell-rich small lymphoid follicles. In all cases, there was a significant increase in IgG4-positive plasma cells compared with controls. In two cases, biopsies before and after steroid treatment were available, and only scattered plasma cells were seen after treatment, none of them expressing IgG4. Review of the literature shows that although pathology commonly appears confined to one organ, patients can have systemic symptoms and fever. In the active period, there is an acute phase response with a high serum concentration of IgG, and during this phase, there is a rapid clinical response to glucocorticoid steroid treatment. CONCLUSION: We believe that hyper-IgG4 disease is an important condition to recognise, as the diagnosis can be readily verified and the outcome with treatment is very good

First Industrial Tests of a Matrix Monitor Correction for the Differential Die-away Technique of Historic Waste Drums

International audienceAbstract The fissile mass in radioactive waste drums filled with compacted metallic residues (spent fuel hulls and nozzles) produced at AREVA NC La Hague reprocessing plant is measured by neutron interrogation with the Differential Die-away measurement Technique (DDT). In the next years, old hulls and nozzles mixed with Ion-Exchange Resins will be measured. The ion-exchange resins increase neutron moderation in the matrix, compared to the waste measured in the current process. In this context, the Nuclear Measurement Laboratory (LMN) of CEA Cadarache has studied a matrix effect correction method, based on a drum monitor, namely a $^3$He proportional counter located inside the measurement cavity. After feasibility studies performed with LMN's PROMETHEE 6 laboratory measurement cell and with MCNPX simulations, this paper presents first experimental tests performed on the industrial ACC (hulls and nozzles compaction facility) measurement system. A calculation vs. experiment benchmark has been achieved by performing dedicated calibration measurements with a representative drum and $^{235}$U samples. The comparison between calculation and experiment shows a satisfactory agreement for the drum monitor. The final objective of this work is to confirm the reliability of the modeling approach and the industrial feasibility of the method, which will be implemented on the industrial station for the measurement of historical wastes

Reduction of the uncertainty due to fissile clusters in radioactive waste characterization with the Differential Die-away Technique

International audienceAREVA NC is preparing to process, characterize and compact old used fuel metallic waste stored at La Hague reprocessing plant in view of their future storage (“Haute Activité Oxyde” HAO project). For a large part of these historical wastes, the packaging is planned in CSD-C canisters (“Colis Standard de Déchets Compacté s”) in the ACC hulls and nozzles compaction facility (“Atelier de Compactage des Coques et embouts”).. This paper presents a new method to take into account the possible presence of fissile material clusters, which may have a significant impact in the active neutron interrogation (Differential Die-away Technique) measurement of the CSD-C canisters, in the industrial neutron measurement station “P2-2”. A matrix effect correction has already been investigated to predict the prompt fission neutron calibration coefficient (which provides the fissile mass) from an internal “drum flux monitor” signal provided during the active measurement by a boron-coated proportional counter located in the measurement cavity, and from a “drum transmission signal” recorded in passive mode by the detection blocks, in presence of an AmBe point source in the measurement cell. Up to now, the relationship between the calibration coefficient and these signals was obtained from a factorial design that did not consider the potential for occurrence of fissile material clusters. The interrogative neutron self-shielding in these clusters was treated separately and resulted in a penalty coefficient larger than 20% to prevent an underestimation of the fissile mass within the drum. In this work, we have shown that the incorporation of a new parameter in the factorial design, representing the fissile mass fraction in these clusters, provides an alternative to the penalty coefficient. This new approach finally does not degrade the uncertainty of the original prediction, which was calculated without taking into consideration the possible presence of clusters. Consequently, the accuracy of the fissile mass assessment is improved by this new method, and this last should be extended to similar DDT measurement stations of larger drums, also using an internal monitor for matrix effect correctio

Performance assessment of amplification and discrimination electronic devices for passive neutron measurements

The knowledge of the fissile material mass is a key challenge to enhance radioactive waste management and to ensure a high level of safety in nuclear industry. Data is analyzed according to the principles of the neutron measurement techniques. As proportional counters filled with 3He gas display high neutron detection efficiency and a good gamma-ray discrimination, they are the reference detector for passive neutron coincidence counting. A charge preamplifier or a current amplifier, depending on applications, collects the electric pulse produced by neutron interaction in the 3He gas and a threshold discriminator produces a logic pulse used for neutron counting. This paper describes the performance assessment of different commercially available electronics from Mirion Technologies, Precision Data Technology (PDT), Mesytec, as well as MONACO electronics originally developed by CEA LIST for fission chamber measurements in experimental reactors. Comparative passive neutron measurements are carried out with these electronics at CEA/DEN Nuclear Measurement Laboratory in Cadarache. Overall, PDT and Mesytec electronics show similar detection efficiency as the ACH-NA98 charge amplifier, which is commonly used in our laboratory for such applications. However, MONACO electronics have a lower detection efficiency, similar to Mirion 7820 current amplifier used in specific high-count rate applications. An optimisation of MONACO settings would probably be necessary to adapt to 3He counters instead of fission chambers

Oxygen Reduction Catalysis at a Dicobalt Center: The Relationship of Faradaic Efficiency to Overpotential

The selective four electron, four proton, electrochemical reduction of O₂ to H₂O in the presence of a strong acid (TFA) is catalyzed at a dicobalt center. The faradaic efficiency of the oxygen reduction reaction (ORR) is furnished from a systematic electrochemical study by using rotating ring disk electrode (RRDE) methods over a wide potential range. We derive a thermodynamic cycle that gives access to the standard potential of O₂ reduction to H₂O in organic solvents, taking into account the presence of an exogenous proton donor. The difference in ORR selectivity for H₂O vs H₂O₂ depends on the thermodynamic standard potential as dictated by the p<i>K</i>_a of the proton donor. The model is general and rationalizes the faradaic efficiencies reported for many ORR catalytic systems

Implementation of a complex monitoring system to track people in the ATLAS detector

International audienceTLAS is one of the four large experiments at the Large Hadron Collider at CERN. The detector itself and the surrounding structures in the cavern of the experiment are accessible for people during maintenance periods. People can easily be isolated and difficult to localize in which case their safety may be compromised in this very complex environment. Therefore a dedicated system called ¿Finding Persons Inside ATLAS Areas¿ has been designed and implemented to track persons in the experimental cavern. It is based on a network of passive infrared sensors which are read out by specific front-end electronics. A complex software architecture provides active tracking of people in the cavern with the possibility to detect abnormal situations where people are possibly in danger. This paper describes the technological choices which have been made for this monitoring system and explains the implementation of the software components. This provides a tool for the operation in the control room of ATLAS to actively follow people in the cavern underground. As the system is data-driven, it can be easily adapted to other environments where similar safety problems exist

Status of the nuclear measurement stations for theprocess control of spent fuel reprocessing at AREVA NC/La Hague

International audienceNuclear measurements are used at AREVA NC/La Hague for the monitoring of spent fuel reprocessing. The process control is based on gamma-ray spectrometry, passive neutron counting and active neutron interrogation, and gamma transmission measurements. The main objectives are criticality-safety, online process monitoring, and the determination of the residual fissile mass and activities in the metallic waste remaining after fuel shearing and dissolution (empty hulls, grids, end pieces), which are put in radioactive waste drums before compaction in stainless steel containers. The whole monitoring system is composed of eight measurement stations which will be described in this paper. The main measurement stations n°1, 3 and 7 are needed for criticality control. Before fuel element shearing for dissolution, station n°1 allows determining the burn-up of the irradiated fuel by gamma-ray spectrometry with HP Ge (high purity germanium) detectors. The burn-up is correlated to the $^{137}$Cs and $^{134}$Cs gamma emission rates. The fuel maximal mass which can be loaded in one bucket of the dissolver is estimated from the lowest burn-up fraction of the fuel element. Station n°3 is dedicated to the control of the correct fuel dissolution, which is performed with a $^{137}$Cs gamma ray measurement with a HP Ge detector. Station n°7 allows estimating the residual fissile mass in the drums filled with the metallic residues, especially the hulls, from passive neutron counting (spontaneous fission and alpha-n reactions) and active interrogation (fission prompt neutrons induced by a pulsed neutron generator) with proportional $^3$He detectors. So far, large campaigns of reprocessing of the UOX fuels with a burn-up rate up to 60 GWd/t have been performed at AREVA/La Hague. This paper presents a brief overview of the current status of the nuclear measurement station

Hydrogen Evolution Catalysis by a Sparsely Substituted Cobalt Chlorin

A sparsely substituted chlorin macrocycle containing a Co­(II) center (<b>1-Co</b>) has been synthesized and structurally characterized. The Co­(II) atom resides in a square planar coordination environment and induces significant out-of-plane distortion of the chlorin macrocycle. The paramagnetic Co­(II) center resides in the macrocycle in a <i>S</i> = ¹/₂ spin state, which displays an axial doublet signal (<i>g</i>_⊥ ≈ 2.3 and <i>g</i>_∥ ≈ 2.03) in the X-band EPR spectrum. The open-shell d-orbital configuration is manifest in the transient absorption spectrum, which reveals an excited-state lifetime of 8.6 ± 0.2 ps for <b>1-Co</b>. The Co­(II) chlorin exhibits a rich oxidation–reduction chemistry with five reversible one-electron waves (three oxidative processes and two reductive processes) observed in the cyclic voltammogram. The reduction processes of <b>1-Co</b> drive hydrogen evolution catalysis. Electrochemical kinetics analysis of HER by <b>1-Co</b> in trifluoroacetic acid reveals a hydrogen evolution mechanism that proceeds by an ECEC mechanism. Benchmarking the catalytic activity, <b>1-Co</b> exhibits higher HER activity at low overpotentials, versus its porphyrin congeners

Hydrogen Evolution Catalysis by a Sparsely Substituted Cobalt Chlorin

A sparsely substituted chlorin macrocycle containing a Co­(II) center (<b>1-Co</b>) has been synthesized and structurally characterized. The Co­(II) atom resides in a square planar coordination environment and induces significant out-of-plane distortion of the chlorin macrocycle. The paramagnetic Co­(II) center resides in the macrocycle in a <i>S</i> = ¹/₂ spin state, which displays an axial doublet signal (<i>g</i>_⊥ ≈ 2.3 and <i>g</i>_∥ ≈ 2.03) in the X-band EPR spectrum. The open-shell d-orbital configuration is manifest in the transient absorption spectrum, which reveals an excited-state lifetime of 8.6 ± 0.2 ps for <b>1-Co</b>. The Co­(II) chlorin exhibits a rich oxidation–reduction chemistry with five reversible one-electron waves (three oxidative processes and two reductive processes) observed in the cyclic voltammogram. The reduction processes of <b>1-Co</b> drive hydrogen evolution catalysis. Electrochemical kinetics analysis of HER by <b>1-Co</b> in trifluoroacetic acid reveals a hydrogen evolution mechanism that proceeds by an ECEC mechanism. Benchmarking the catalytic activity, <b>1-Co</b> exhibits higher HER activity at low overpotentials, versus its porphyrin congeners