Characterisation of Nd-doped calcium aluminosilicate parent glasses designed for the preparation of zirconolite-based glass-ceramic waste forms

4 pagesZirconolite-based (nominally CaZrTi2O7) glass-ceramics belonging to the SiO2-Al2O3-CaO-ZrO2-TiO2 system are good waste forms for the specific immobilisation of actinides. The understanding of their crystallisation processes implies to investigate the structure of the glass. Thus, the environment around Ti, Zr (nucleating agents) and Nd (trivalent actinides surrogate) was characterised in parent glasses. Electron spin resonance (ESR) study of the small amount of Ti3+ occurring in the glass enabled to identify two types of sites for titanium: the main one is of C4v or D4h symmetry. EXAFS showed that Zr occupied a quite well defined 6-7-fold coordinated site with second neighbours which could correspond to Ca/Ti and Zr. Nd environment was probed by optical spectroscopies (absorption, fluorescence), ESR and EXAFS. All these techniques demonstrated that the environment around Nd was very constrained by the glassy network. Notably, Nd occupies a highly distorted 8-9-fold coordinated site in the parent glass

Development of Vitrification Process and Glass Formulation for Nuclear Waste Conditioning

The vitrification of high-level waste is the internationally recognized standard to minimize the impact to the environment resulting from waste disposal as well as to minimize the volume of conditioned waste to be disposed of. COGEMA has been vitrifying high-level waste industrially for over 20 years and is currently operating three commercial vitrification facilities based on a hot metal crucible technology, with outstanding records of safety, reliability and product quality. To further increase the performance of vitrification facilities, CEA and COGEMA have been developing the cold crucible melter technology since the beginning of the 1980s. This type of melter is characterized by a virtually unlimited equipment service life and a great flexibility in dealing with various types of waste and allowing development of high temperature matrices. In complement of and in parallel with the vitrification process, a glass formulation methodology has been developed by the CEA in order to tailor matrices for the wastes to be conditioned while providing the best adaptation to the processing technology. The development of a glass formulation is a trade-off between material properties and qualities, technical feasibility, and disposal safety criteria. It involves non-radioactive and radioactive laboratories in order to achieve a comprehensive matrix qualification. Several glasses and glass ceramics have thus been studied by the CEA to be compliant with industrial needs and waste characteristics: glasses or other matrices for a large spectrum of fission products, or for high contents of specifics elements such as sodium, phosphate, iron, molybdenum, or actinides. New glasses or glass-ceramics designed to minimize the final wasteform volume for solutions produced during the reprocessing of high burnup fuels or to treat legacy wastes are now under development and take benefit from the latest CEA hot-laboratories and technology development. The paper presents the CEA state-of-the-art in developing matrices or glasses and provides several examples

Diffuse large B-cell lymphoma of Waldeyer's ring has distinct clinicopathologic features: a GELA study

Background Diffuse large B-cell lymphomas (DLBCLs) arising in specific extranodal sites have peculiar clinicopathologic features. Patients and methods We analyzed a cohort of 187 primary Waldeyer's ring (WR) DLBCLs retrieved from GELA protocols using anthracyclin-based polychemotherapy. Results Most patients (92%) had stage I-II disease. A germinal center B-cell-like (GCB) immunophenotype was observed in 61%, and BCL2 expression in 55%, of WR DLBCLs. BCL2, BCL6, IRF4 and MYC breakpoints were observed in, respectively, 3 of 42 (7%), 9 of 36 (25%), 2 of 26 (8%) and 4 of 40 (10%) contributive cases. A variable follicular pattern was evidenced in 30 of 68 (44%) large biopsy specimens. The 5-year progression-free survival (PFS) and the overall survival (OS) of 153 WR DLBCL patients with survival information were 69.5% and 77.8%, respectively. The GCB immunophenotype correlated with a better OS (P=0.0015), while BCL2 expression predicted a worse OS (P=0.037), an effect overcome by the GCB/non-GCB classification. Compared with matched nodal DLBCLs, WR DLBCLs with no age-adjusted international prognostic index factor disclosed a better 5-year PFS rate (77.5% versus 70.7%; P=0.03). Conclusions WR DLBCLs display distinct clinicopathologic features compared with conventional DLBCLs, with usual localized-stage disease, common follicular features and a high frequency of GCB immunophenotype contrasting with a low rate of BCL2 rearrangements. In addition, they seem to be associated with a better outcome than their nodal counterpar

Exploring the Nexus of Alzheimer’s Disease and Related Dementias with Cancer and Cancer Therapies

Recent population studies suggest an intriguing inverse relationship between several types of cancer and neurodegenerative diseases, including Alzheimer’s disease. Understanding the intersection of the underlying biology for these two distinct families of diseases with one another may offer novel approaches to identify new therapeutic approaches and possible opportunities to repurpose existing drug candidates. The Alzheimer’s Association and the Alzheimer’s Drug Discovery Foundation convened a one day workshop to delve into this discussion. Workshop participants outlined research focus areas, potential collaborations and partnerships for future action

Long-term follow-up of patients treated with radiotherapy alone for early-stage histologically aggressive non-Hodgkin's lymphoma

Historically localised aggressive non-Hodgkin's lymphoma (NHL) has been treated with involved field radiotherapy (RT), chemotherapy, or a combination of both modalities. The current weight of evidence supports a preference for combined modality treatment (CMT). Increased patient age at diagnosis is well recognised as a poor prognostic indicator in NHL, but despite this some perceive CMT as too toxic for use in the elderly. As a result, some older patients continue to be offered RT alone. Here, we present long-term follow-up of 377 adults of all ages treated with RT alone for early-stage diffuse large-cell lymphoma on British National Lymphoma Investigation trials between 1974 and 1997. 10-year cause-specific survival in patients older than 60 years was poor and significantly inferior to that in younger patients (47 and 75% respectively; P<0.001). There is growing evidence that short-course chemotherapy, with or without RT, is superior to RT alone in early-stage aggressive NHL, in elderly as well as in younger patients. Increased age alone should not exclude patients from systemic treatment for early-stage aggressive NHL