23 research outputs found

    Degree of Pyritization and Methylmercury Analysis, Weeks Bay Alabama

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    Methylmercury (MeHg) production is magnified in the natural environment by geochemical influxes and an active sulfate reducing bacteria community. It has been found that the presence of sulfides, excess nutrients, and the type of depositional environment (normal marine or euxinic) greatly influences MeHg production and degree of pyritization (DOP). The aim of this research is to investigate a possible connection between MeHg accumulation and the DOP in Weeks Bay sediment. Collected sediment samples have confirmed a significant presence of total reduced sulfides, inorganic mercury, reactive iron, and total organic carbon. Pyritization results indicate a normal marine environment and, of the three measured elements (S, Fe, and C,) carbon and sulfur are the dominant limiting factors to the DOP in Weeks Bay. Current geochemical and pH/redox conditions favor MeHg and pyrite production. The quantified pyrite greatly exceeds that of MeHg indicating DOP inhibits MeHg precipitation

    Silicon carbide - graphene nano-gratings on 4H and 6H semi-insulating SiC

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    A technical methodology of fabrication of hierarchically scaled multitude graphene nanogratings with varying pitches ranging from the micrometer down to sub 40 nm scale combined with sub 10 nm step heights on 4H and 6H semi-insulating SiC for length scale measurements is proposed. The nanogratings were fabricated using electron-beam lithography combined with dry etching of graphene, incorporating a standard semiconductor processing technology. A scientific evaluation of critical dimension, etching step heights, and surface characterization of graphene nanograting on both polytypes were compared and evaluated

    Evaluation of Proclarix in the diagnostic work‐up of prostate cancer

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    Objectives: The use of multiparametric magnetic resonance imaging (mpMRI) has been widely adopted in the diagnostic work‐up for suspicious prostate cancer (PCa) and is recommended in most current guidelines. However, mpMRI lesions are often indeterminate and/or turn out to be false‐positive on prostate biopsy. The aim of this work was to evaluate Proclarix, a biomarker test for the detection of relevant PCa, regarding its diagnostic value in all men before biopsy and in men with indeterminate lesions on mpMRI (PI‐RADS 3) during work‐up for PCa. Materials and Methods: Men undergoing mpMRI‐targeted and systematic biopsy of the prostate were prospectively enrolled. The Proclarix test was evaluated for the detection accuracy of clinically significant PCa (csPCa) defined as Grade Group ≥ 2 and its association to mpMRI results. Further, Proclarix's performance was also tested when adapted to prostate volume (Proclarix density) and performance compared to PSA density (PSAD). Results: A total of 150 men with a median age of 65 years and median PSA of 5.8 ng/mL were included in this study. CsPCa was diagnosed in 65 (43%) men. Proclarix was significantly associated with csPCa and higher PI‐RADS score (p < 0.001). At the pre‐defined cut‐off of 10%, Proclarix's sensitivity for csPCa was 94%, specificity 19%, negative predictive value 80% and positive predictive value 47%. Proclarix density showed the highest AUC for the detection of csPCa of 0.77 (95%CI: 0.69–0.85) compared to PSA, PSAD and Proclarix alone. Proclarix was able to identify all six csPCa in men with PI‐RADS 3 lesions (n = 28), whereas PSAD missed two out of six. At optimized cut‐offs, Proclarix density outperformed PSAD by potentially avoiding 41% of unnecessary biopsies. Conclusion: Proclarix demonstrates high sensitivity in detecting csPCa but may still result in unnecessary biopsies. However, Proclarix density was able to outperform PSAD and Proclarix and was found to be useful in men with PI‐RADS 3 findings by safely avoiding unnecessary biopsies without missing csPCa
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