Removal of Sulfate Ion From AN-107 by Evaporation

Hanford low-activity waste solutions contain sulfate, which can cause accelerated corrosion of the vitrification melter and unacceptable operating conditions. A method is needed to selectively separate sulfate from the waste. An experiment was conducted to evaluate evaporation for removing sulfate ion from Tank AN-107 low-activity waste. Two evaporation steps were performed. In the first step, the volume was reduced by 55% while in the second step, the liquid volume was reduced another 22%. Analysis of the solids precipitated during these evaporations revealed that large amounts of sodium nitrate and nitrite co-precipitated with sodium sulfate. Many other waste components precipitated as well. It can be concluded that sulfate removal by precipitation is not selective, and thus, evaporation is not a viable option for removing sulfate from the AN-107 liquid

Patient Barriers to Follow-Up Care for Breast and Cervical Cancer Abnormalities

BACKGROUND: Women with breast or cervical cancer abnormalities can experience barriers to timely follow-up care, resulting in delays in cancer diagnosis. Patient navigation programs that identify and remove barriers to ensure timely receipt of care are proliferating nationally. The study used a systematic framework to describe barriers, including differences between African American and Latina women; to determine recurrence of barriers; and to examine factors associated with barriers to follow-up care. METHODS: Data originated from 250 women in the intervention arm of the Chicago Patient Navigation Research Program (PNRP). The women had abnormal cancer screening findings and navigator encounters. Women were recruited from a community health center and a publicly owned medical center. After describing proportions of African American and Latina women experiencing particular barriers, logistic regression was used to explore associations between patient characteristics, such as race/ethnicity, and type of barriers. RESULTS: The most frequent barriers occurred at the intrapersonal level (e.g., insurance issues and fear), while institutional-level barriers such as system problems with scheduling care were the most commonly recurring over time (29%). The majority of barriers (58%) were reported in the first navigator encounter. Latinas (81%) reported barriers more often than African American women (19%). Differences in race/ethnicity and employment status were associated with types of barriers. Compared to African American women, Latinas were more likely to report an intrapersonal level barrier. Unemployed women were more likely to report an institutional level barrier. CONCLUSION: In a sample of highly vulnerable women, there is no single characteristic (e.g., uninsured) that predicts what kinds of barriers a woman is likely to have. Nevertheless, navigators appear able to easily resolve intrapersonal-level barriers, but ongoing navigation is needed to address system-level barriers. Patient navigation programs can adopt the PNRP barriers framework to assist their efforts in assuring timely follow-up care

An alternative mode of microRNA target recognition

MicroRNAs (miRNAs) regulate mRNA targets through perfect pairing with their seed region (positions 2-7). Recently, a precise genome-wide map of miRNA interaction sites in mouse brain was generated by high-throughput sequencing and analysis of clusters of ∼50-nucleotide mRNA tags cross-linked to Argonaute (Ago HITS-CLIP). By analyzing Ago HITS-CLIP 'orphan clusters'-Ago binding regions from HITS-CLIP that cannot be explained by canonical seed matches-we have now identified an alternative binding mode used by miRNAs. Specifically, G-bulge sites (positions 5-6) are often bound and regulated by miR-124 in brain. More generally, bulged sites comprise ≥15% of all Ago-miRNA interactions in mouse brain and are evolutionarily conserved. We call position 6 the 'pivot' nucleotide and suggest a model in which a transitional 'nucleation bulge' leads to functional bulge mRNA-miRNA interactions, expanding the number of potential miRNA regulatory sites. © 2012 Nature America, Inc. All rights reserved

A post-transcriptional mechanism pacing expression of neural genes with precursor cell differentiation status

Nervous system (NS) development relies on coherent upregulation of extensive sets of genes in a precise spatiotemporal manner. How such transcriptome-wide effects are orchestrated at the molecular level remains an open question. Here we show that 3′-untranslated regions (3′ UTRs) of multiple neural transcripts contain AU-rich cis-elements (AREs) recognized by tristetraprolin (TTP/Zfp36), an RNA-binding protein previously implicated in regulation of mRNA stability. We further demonstrate that the efficiency of ARE-dependent mRNA degradation declines in the neural lineage because of a decrease in the TTP protein expression mediated by the NS-enriched microRNA miR-9. Importantly, TTP downregulation in this context is essential for proper neuronal differentiation. On the other hand, inactivation of TTP in non-neuronal cells leads to dramatic upregulation of multiple NS-specific genes. We conclude that the newly identified miR-9/TTP circuitry limits unscheduled accumulation of neuronal mRNAs in non-neuronal cells and ensures coordinated upregulation of these transcripts in neurons