22 research outputs found

    INDEPENDENT REVIEW OF THE X-701B GROUNDWATER REMEDY, PORTSMOUTH, OHIO: TECHNICAL EVALUATION AND RECOMMENDATIONS

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    The Department of Energy Portsmouth Paducah Project Office requested assistance from Department of Energy Office of Environmental Management (EM-22) to provide independent technical experts to evaluate past and ongoing remedial activities at the Portsmouth facility that were completed to address TCE contamination associated with the X-701B groundwater plume and to make recommendations for future efforts. The Independent Technical Review team was provided with a detailed and specific charter. The charter requested that the technical team first review the past and current activities completed for the X-701B groundwater remedy for trichloroethene (TCE) in accordance with a Decision Document that was issued by Ohio EPA on December 8, 2003 and a Work Plan that was approved by Ohio EPA on September 22, 2006. The remedy for X-701B divides the activities into four phases: Phase I - Initial Source Area Treatment, Phase II - Expanded Source Area Treatment, Phase III - Evaluation and Reporting, and Phase IV - Downgradient Remediation and Confirmation of Source Area Treatment. Phase I of the remedy was completed during FY2006, and DOE has now completed six oxidant injection events within Phase II. The Independent Technical Review team was asked to evaluate Phase II activities, including soil and groundwater results, and to determine whether or not the criteria that were defined in the Work Plan for the Phase II end point had been met. The following criteria are defined in the Work Plan as an acceptable Phase II end point: (1) Groundwater samples from the identified source area monitoring wells have concentrations below the Preliminary Remediation Goal (PRG) for TCE in groundwater, or (2) The remedy is no longer effective in removing TCE mass from the source area. In addition, the charter specifies that if the Review Team determines that the Phase II endpoint has not been reached, then the team should address the following issues: (1) If additional injection events are recommended, the team should identify the type of injection and target soil horizon for these injections; (2) Consider the feasibility of declaring Technical Impracticability and proceeding with the RCRA Cap for the X-701B; and (3) Provide a summary of other cost-effective technologies that could be implemented (especially for the lower Gallia). The Independent Technical Review team focused its evaluation solely on the X-701B source zone and contaminant plume. It did not review current or planned remedial activities at other plumes, waste areas, or landfills at the Portsmouth site, nor did it attempt to integrate such activities into its recommendations for X-701B. However, the ultimate selection of a remedy for X-701B by site personnel and regulators should take into account potentially synergistic efforts at other waste areas. Assessment of remedial alternatives in the context of site-wide management practices may reveal opportunities for leveraging and savings that would not otherwise be identified. For example, the cost of source-zone excavation or construction of a permeable reactive barrier at X-701B might be substantially reduced if contaminated soil could be buried on site at an existing or planned landfill. This allowance would improve the feasibility and competitiveness of both remedies. A comprehensive examination of ongoing and future environmental activities across the Portsmouth Gaseous Diffusion Plant is necessary to optimize the selection and timing of X-701B remediation with respect to cleanup efficiency, safety, and economics. A selected group of technical experts attended the technical workshop at the Portsmouth Gaseous Diffusion Plant from November 18 through 21, 2008. During the first day of the workshop, both contractor and DOE site personnel briefed the workshop participants and took them on a tour of the X-701B site. The initial briefing was attended by representatives of Ohio EPA who participated in the discussions. On subsequent days, the team reviewed baseline data and reports, were provided additional technical information from site personnel, evaluated work plans, determined critical issues and uncertainties, and recommended alternatives. This report documents the findings and recommendations of the independent technical review team

    High-resolution optoacoustic imaging of tissue responses to vascular-targeted therapies.

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    The monitoring of vascular-targeted therapies using magnetic resonance imaging, computed tomography or ultrasound is limited by their insufficient spatial resolution. Here, by taking advantage of the intrinsic optical properties of haemoglobin, we show that raster-scanning optoacoustic mesoscopy (RSOM) provides high-resolution images of the tumour vasculature and of the surrounding tissue, and that the detection of a wide range of ultrasound bandwidths enables the distinction of vessels of differing size, providing detailed insights into the vascular responses to vascular-targeted therapy. Using RSOM to examine the responses to vascular-targeted photodynamic therapy in mice with subcutaneous xenografts, we observed a substantial and immediate occlusion of the tumour vessels followed by haemorrhage within the tissue and the eventual collapse of the entire vasculature. Using dual-wavelength RSOM, which distinguishes oxyhaemoglobin from deoxyhaemoglobin, we observed an increase in oxygenation of the entire tumour volume immediately after the application of the therapy, and a second wave of oxygen reperfusion approximately 24 h thereafter. We also show that RSOM enables the quantification of differences in neoangiogenesis that predict treatment efficacy

    Identification of alternative protein targets of glutamate-ureido-lysine associated with PSMA tracer uptake in prostate cancer cells

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    Prostate-specific membrane antigen (PSMA) is highly overexpressed in most prostate cancers and is clinically visualized using PSMA-specific probes incorporating glutamate-ureido-lysine (GUL). PSMA is effectively absent from certain high-mortality, treatment-resistant subsets of prostate cancers, such as neuroendocrine prostate cancer (NEPC); however, GUL-based PSMA tracers are still reported to have the potential to identify NEPC metastatic tumors. These probes may bind unknown proteins associated with PSMA-suppressed cancers. We have identified the up-regulation of PSMA-like aminopeptidase NAALADaseL and the metabotropic glutamate receptors (mGluRs) in PSMA-suppressed prostate cancers and find that their expression levels inversely correlate with PSMA expression and are associated with GUL-based radiotracer uptake. Furthermore, we identify that NAALADaseL and mGluR expression correlates with a unique cell cycle signature. This provides an opportunity for the future study of the biology of NEPC and potential therapeutic directions. Computationally predicting that GUL-based probes bind well to these targets, we designed and synthesized a fluorescent PSMA tracer to investigate these proteins in vitro, where it shows excellent affinity for PSMA, NAALADaseL, and specific mGluRs associated with poor prognosis
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