[en] This plan describes the process for managing research generated medical waste at Sandia National Laboratories/California. It applies to operations at the Chemical and Radiation Detection Laboratory (CRDL), Building 968, and other biosafety level 1 or 2 activities at the site. It addresses the accumulation, storage, treatment and disposal of medical waste and sharps waste. It also describes the procedures to comply with regulatory requirements and SNL policies applicable to medical waste

[en] Separation and pre-concentration of the desired analyte is often a critical step in many radioanalytical methods. Current procedures for separating and concentrating analytes for detection are complex, and can be both expensive and time consuming. Therefore, the purpose of this research is to develop an alternative method of separating lanthanide ions through the use of an extraction chromatography resin containing a Klaui ligand salt. This research is a continuation of a concerted effort to develop new methods of detecting small concentrations of radionuclides and lanthanides using Klaui ligands. The Klaui ligands, C5Me5Co(OP(OR)2)3- (R=Me, Et, n-Pr) (LOR-), have unique affinity for lanthanide and actinide ions in the presence of competing metal ions. The use of 1 wt% NaLOR (R=Et or n-Pr) adsorbed onto resin support has been shown to extract lanthanide ions from aqueous nitric acid solutions of different concentrations. In order to further evaluate the utility of these materials in radiochemical separation, the selectivity of the resins for the different lanthanide ions was examined by measuring the distribution coefficients (Kd) for a series of lanthanides over a range of solution conditions. Based on prior research with actinide ions, it was hypothesized that the lanthanide ions would bond strongly with the Klaui ligands. The success of this research is important, because it will assist in expanding and improving current automated radiochemical methods, which will decrease the cost of developing and implementing radiochemical methods. To date, Kd values have been determined for Eu+3, Nd+3 and Pr+3 under varying nitric acid (HNO3) concentration, using a resin consisting of 1.0 wt% NaLOPr on Amberlite XAD-7HP. The dependence of the Kd values for Eu+3 has also been examined as a function of the ligand-to-europium ratio and the nitrate concentration. Decreasing Kd values were obtained upon increasing the nitric acid concentration, indicating protonation of the ligand, which competes with binding of the lanthanide ions. As expected, increasing the Klaui ligand-to-europium ratio results in increasing Kd, but no conclusions could be made from these data regarding stoichiometry of the complex formed on the resin. No dependence of the Kd on the nitrate concentration was observed, supporting the notion that the HNO3 dependence is dominated by the presence of the acidic hydronium ion (as opposed to the nitrate ion). Future work will involve the determination of the Kd values for the remainder of the lanthanide series to further assess the potential of the Klaui ligand for intra-group lanthanide separations.

[en] Acute myeloid leukemia and chronic lymphocytic leukemia are associated with benzene exposure. In mice, benzene induces chromosomal breaks as a primary mode of genotoxicity in the bone marrow (BM). Benzene-induced DNA lesions can lead to changes in hematopoietic stem cells (HSC) that give rise to leukemic clones. To gain insight into the mechanism of benzene-induced leukemia, we investigated the DNA damage repair and response pathways in total bone marrow and bone marrow fractions enriched for HSC from male 129/SvJ mice exposed to benzene by inhalation. Mice exposed to 100 ppm benzene for 6 h per day, 5 days per week for 2 week showed significant hematotoxicity and genotoxicity compared to air-exposed control mice. Benzene exposure did not alter the level of apoptosis in BM or the percentage of HSC in BM. RNA isolated from total BM cells and the enriched HSC fractions from benzene-exposed and air-exposed mice was used for microarray analysis and quantitative real-time RT-PCR. Interestingly, mRNA levels of DNA repair genes representing distinct repair pathways were largely unaffected by benzene exposure, whereas altered mRNA expression of various apoptosis, cell cycle, and growth control genes was observed in samples from benzene-exposed mice. Differences in gene expression profiles were observed between total BM and HSC. Notably, p21 mRNA was highly induced in BM but was not altered in HSC following benzene exposure. The gene expression pattern suggests that HSC isolated immediately following a 2 weeks exposure to 100 ppm benzene were not actively proliferating. Understanding the toxicogenomic profile of the specific target cell population involved in the development of benzene-associated diseases may lead to a better understanding of the mechanism of benzene-induced leukemia and may identify important interindividual and tissue susceptibility factors

[en] Soil is an essential component of all terrestrial ecosystems and is under increasing threat from human activity. Techniques available for removing radioactive contamination from soil and aquatic substrates are limited and often costly to implement; particularly over large areas. Frequently, bulk soil removal, with its attendant consequences, is a significant component of the majority of contamination incidents. Alternative techniques capable of removing contamination or exposure pathways without damaging or removing the soil are therefore of significant interest. An increasing number of old nuclear facilities are entering 'care and maintenance', with significant ground contamination issues. Phyto-remediation - the use of plants' natural metabolic processes to remediate contaminated sites is one possible solution. Its key mechanisms include phyto-extraction and phyto-stabilisation. These are analogues of existing remedial techniques. Further, phyto-remediation can improve soil quality and stability and restore functionality. Information on the application of phyto-remediation in the nuclear industry is widely distributed over an extended period of time and sources. It is therefore difficult to quickly and effectively identify which plants would be most suitable for phyto-remediation on a site by site basis. In response, a phyto-remediation tool has been developed to address this issue. Existing research and case studies were reviewed to understand the mechanisms of phyto-remediation, its effectiveness and the benefits and limitations of implementation. The potential for cost recovery from a phyto-remediation system is also briefly considered. An overview of this information is provided here. From this data, a set of matrices was developed to guide potential users through the plant selection process. The matrices take the user through a preliminary screening process to determine whether the contamination present at their site is amenable to phyto-remediation, and to give a rough indication as to what plants might be suitable. The second two allow the user to target specific plant species that would be most likely to successfully establish based on prevailing site conditions. The outcome of this study is a phyto-remediation tool that can facilitate the development of phyto-remediation projects, avoiding the need for in-depth research to identify optimal plant species on a case-by-case basis. (authors)

[en] Results are presented indicating a linear relationship between irradiation dose (10–60 kGy) and the quantity of 2-dodecylcyclobutanone produced in irradiated frozen (-46°C) chicken meat. 2-Dodecylcyclobutanone was found in chicken meat sterilized (at -40°C) by gamma and electron beam irradiation 12 years previously and used for toxicity clearance. After freeze-drying the irradiated chicken samples still contained 2-dodecylcyclobutanone indicating that it was present in the diets tested. The compound was not detected in chicken meat sterilized by thermal processing 13 years ago. In addition, there was evidence that 2-tetradecylcyclobutanone was also present in the irradiation sterilized samples

[en] Proteins can use aromatic side-chains to stabilize bound cationic ligands through cation-π interactions. The first example of the reciprocal process, termed π-cation, is reported in which a cationic protein side-chain stabilizes a neutral aromatic ligand. Site-directed mutagenesis revealed that an arginine side-chain located in the deep binding pocket of a monoclonal antibody (4D5) is essential for binding the neutral polynuclear aromatic hydrocarbon benzo[a]pyrene. This Arg was very likely selected for in the primary response, furhter underscoring the importance of the π-cation interaction for ligand binding, which should be considered in protein analysis and design when ligands include aromatic groups

[en] A local geometric error correction method is developed for a metrological scanning probe microscope. The method corrects geometric errors in stage displacements using the interferometric measurements of angular position and known geometric offsets. Local and global error correction methods are considered and general scaling dependences on the number of measured steps or points are derived and compared. For the local method, the total uncertainty scales the same or decreases with a sufficient number of measurement steps compared with the global method. Implementation of the local geometric error correction method is demonstrated on measurements of a three-dimensional height standard artefact. The applied error correction method reduces the contribution of geometric errors to the uncertainty budget by two orders of magnitude. The presented approach can be extended to any scanning technique where a measurement translation mechanism can be identified and accurately quantified by relating the measured values with a measurand. (paper)

[en] Experimental ¹⁵N-¹H and ¹H-¹H residual dipolar couplings (RDCs) for the asparagine (Asn) and glutamine (Gln) side chains of hen egg-white lysozyme are measured and analysed in conjunction with ¹N relaxation data, information about χ¹ torsion angles in solution and molecular dynamics simulations. The RDCs are compared to values predicted from 16 high-resolution crystal structures. Two distinct groups of Asn and Gln side chains are identified. The first contains residues whose side chains show a fixed, relatively rigid, conformation in solution. For these residues there is good agreement between the experimental and predicted RDCs. This agreement improves when the experimental order parameter, S, is included in the calculation of the RDCs from the crystal structures. The comparison of the experimental RDCs with values calculated from the X-ray structures shows that the similarity between the oxygen and nitrogen electron densities is a limitation to the correct assignment of the Asn and Gln side-chain orientation in X-ray structures. In the majority of X-ray structures a 180 deg. rotation about χ² or χ³, leading to the swapping of N^δε2 and O^δε1, is necessary for at least one Asn or Gln residue in order to achieve good agreement between experimental and predicted RDCs. The second group contains residues whose side chains do not adopt a single, well-defined, conformation in solution. These residues do not show a correlation between the experimental and predicted RDCs. In many cases the family of crystal structures shows a range of orientations for these side chains, but in others the crystal structures show a well-defined side-chain position. In the latter case, this is found to arise from crystallographic contacts and does not represent the behaviour of the side chain in solution

[en] Purpose: The clinical late effects of intraoperative radiotherapy (IORT) on peripheral nerve were investigated in a foxhound model. Methods and Materials: Between 1982 and 1987, 40 animals underwent laparotomy with intraoperative radiotherapy of doses from 0-75 Gy administered to the right lumbosacral plexus. Subsequently, all animals were monitored closely and sacrificed to assess clinical effects to peripheral nerve. This analysis reports final clinical results of all animals, with follow-up to 5 years. Results: All animals treated with ≥ 25 Gy developed ipsilateral neuropathy. An inverse relationship was noted between intraoperative radiotherapy dose and time to neuropathy, with an effective dose for 50% paralysis (ED₅₀) of 17.2 Gy. One of the animals treated with 15 Gy IORT developed paralysis, after a much longer latency than the other animals. Conclusions: Doses of 15 Gy delivered intraoperatively may be accompanied by peripheral neuropathy with long-term follow-up. This threshold is less than that reported with shorter follow-up. The value of ED₅₀ determined here is in keeping with data from other animal trials, and from clinical trials in humans

[en] The paper presents the study of the possibilities of optical monitoring of the fluid flow velocity. An optical fiber with an array of Bragg fiber gratings, the central wavelengths of which varied depending on the velocity of the transmitted stream, was used as a sensitive element. The advantage of the developed method lies in the possibility of additional simultaneous measurement of the temperature of the liquid—which allows us to produce hot-wire anemometers, or to exclude the influence of temperature on measurements of the flow velocity. The sensitivity of the developed method was 697 pm/(m/s).