Radiation stability of sodium titanate ion exchange materials

Sodium titanate and sodium titanate loaded macroreticular resin are being considered as ion exchangers to remove /sup 90/Sr and actinides from the large volume of defense waste stored at Hanford Site in Washington. Preliminary studies to determine the radiation effect on Sr/sup +2/ and I/sup -/ capacity of these ion-exchange materials were conducted. Samples of sodium titanate powder, sodium titanate loaded macroreticular resin, as well as the nitrate form of macroreticular anion resin were irradiated with up to 2 x 10/sup 9/ Rads of /sup 60/Co gamma rays. Sodium titanate cation capacity decreased about 50% while the sodium titanate loaded macroeticular resin displayed a dramatic decrease in cation capacity when irradiated with 10/sup 8/-10/sup 9/ Rad. The latter decrease is tentatively ascribed to radiation damage to the organic portion which subsequently inhibits interaction with the contained sodium titanate. The anion capacity of both macroreticular resin and sodium titanate loaded macroreticular resin exhibited significant decreases with increasing radiation exposure. These results suggest that consideration should be given to the potential effects of radiation degradation if column regeneration is to be used. 5 figures, 2 tables

Characterization of an aged WESF capsule

A joint effort by SNLA and ORNL was initiated for a detailed characterization of an 18-year-old WESF /sup 137/Cs source which has been used in the Sandia Irradiator for Dried Sewage Solids. The study included evaluation of the inner and outer stainless steel capsules by optical metallography, electron microprobe, and physical testing. Analysis of the residual atmospheres within the two containers was also done. The CsCl was analyzed for isotopic content and impurities. No potential problem areas, including corrosion, were found

Genome-wide study of DNA methylation shows alterations in metabolic, inflammatory, and cholesterol pathways in ALS

Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease with an estimated heritability between 40 and 50%. DNA methylation patterns can serve as proxies of (past) exposures and disease progression, as well as providing a potential mechanism that mediates genetic or environmental risk. Here, we present a blood-based epigenome-wide association study meta-analysis in 9706 samples passing stringent quality control (6763 patients, 2943 controls). We identified a total of 45 differentially methylated positions (DMPs) annotated to 42 genes, which are enriched for pathways and traits related to metabolism, cholesterol biosynthesis, and immunity. We then tested 39 DNA methylation–based proxies of putative ALS risk factors and found that high-density lipoprotein cholesterol, body mass index, white blood cell proportions, and alcohol intake were independently associated with ALS. Integration of these results with our latest genome-wide association study showed that cholesterol biosynthesis was potentially causally related to ALS. Last, DNA methylation at several DMPs and blood cell proportion estimates derived from DNA methylation data were associated with survival rate in patients, suggesting that they might represent indicators of underlying disease processes potentially amenable to therapeutic interventions