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Sample records for osmium 186 target

  1. Accelerator Production and Separations for High Specific Activity Rhenium-186

    SciTech Connect

    Jurisson, Silvia S.; Wilbur, D. Scott

    2016-04-01

    Tungsten and osmium targets were evaluated for the production of high specific activity rhenium-186. Rhenium-186 has potential applications in radiotherapy for the treatment of a variety of diseases, including targeting with monoclonal antibodies and peptides. Methods were evaluated using tungsten metal, tungsten dioxide, tungsten disulfide and osmium disulfide. Separation of the rhenium-186 produced and recycling of the enriched tungsten-186 and osmium-189 enriched targets were developed.

  2. Sources of osmium to the modern oceans: New evidence from the 190Pt-186Os system

    USGS Publications Warehouse

    McDaniel, D.K.; Walker, R.J.; Hemming, S.R.; Horan, M.F.; Becker, H.; Grauch, R.I.

    2004-01-01

    High precision Os isotope analysis of young marine manganese nodules indicate that whereas the composition of modern seawater is radiogenic with respect to 187Os/188Os, it has 186Os/188Os that is within uncertainty of the chondritic value. Marine Mn nodule compositions thus indicate that the average continental source of Os to modern seawater had long-term high Re/Os compared to Pt/Os. Analyses of loess and freshwater Mn nodules support existing evidence that average upper continental crust (UCC) has resolvably suprachondritic 186Os/188Os, as well as radiogenic 187Os/188Os. Modeling the composition of seawater as a two-component mixture of oceanic/cosmic Os with chondritic Os compositions and continentally-derived Os demonstrates that, insofar as estimates for the composition of average UCC are accurate, congruently weathered average UCC cannot be the sole continental source of Os to seawater. Our analysis of four Cambrian black shales confirm that organic-rich sediments can have 187Os/188Os ratios that are much higher than average UCC, but 186Os/188Os compositions that are generally between those of chondrites and average-UCC. Preferential weathering of black shales can result in dissolved Os discharged to the ocean basins that has a much lower 186Os/188Os than does average upper crust. Modeling the available data demonstrates that augmentation of estimated average UCC compositions with less than 0.1% additional black shale and 1.4% additional ultramafic rock can produce a continental end-member Os isotopic composition that satisfies the requirements imposed by the marine Mn nodule data. The interplay of these two sources provides a mechanism by which the 187Os/188Os of seawater can change as sources and weathering conditions change, yet seawater 186Os/188Os varies only minimally. ?? 2004 Elsevier Ltd.

  3. Osmium in the rivers

    SciTech Connect

    Sharma, M. |; Wasserburg, G.J.

    1997-12-01

    There is a large uncertainty in our understanding of the behavior of osmium during weathering and transport into deep oceans and the osmium budget of the oceans. The problem stems chiefly from the lack of osmium data on the dissolved load in the rivers and in the estuaries. In this study, the concentration and isotopic composition of osmium have been determined in three North American rivers (the Mississippi, the Columbia, and the Connecticut) and one river draining central Europe and flowing into the Baltic Sea (the Vistula). Osmium concentration in the Mississippi and the Vistula is about 45 femto mol kg{sup -1}; it is about 14 and 15 femto mol kg{sup -1} for the Connecticut and the Columbia, respectively. The {sup 187}Os/{sup 186}Os ratios estimated for the Mississippi and the Vistula are 10.4 and 10.7, respectively. For the Connecticut and the Columbia {sup 187}Os/{sup 186}Os = 8.8 and 14.4, respectively. Of all the rivers examined, the Mississippi is by far the largest, supplying {approximately}1.6% of the total annual world river flow. Its osmium isotopic composition is identical to the upper Mississippi valley loesses indicating (1) congruent dissolution of the bedrock and (2) little or no impact of anthropogenic sources on the osmium isotopic composition of the dissolved load. The latter observation indicates that the upper limit of the anthropogenic input in the dissolved osmium load of the Mississippi outflow is about 250 g yr{sup -1}. While the osmium concentration of the Vistula is high the isotopic composition does not appear to have been affected by substantial pollution. The river data can be used to put limits on the mean residence time of osmium in the oceans ({bar {tau}}{sub Os}) and on the osmium budget of the oceans. 17 refs., 1 fig., 1 tab.

  4. MiR-186 Inhibited Migration of NSCLC via Targeting cdc42 and Effecting EMT Process

    PubMed Central

    Dong, Ying; Jin, Xintian; Sun, Zhiqiang; Zhao, Yueming; Song, Xianjing

    2017-01-01

    In this study, qRT-PCR was employed to identify that miR-186 expression level in NSCLC tissues are highly associated with lymph node metastasis. In addition, through the application of western blotting, luciferase assay and qRT-PCR, it was found that miR-186 targeted 3′UTR of cdc42 mRNA and down-regulated cdc42 protein level in a post-transcriptional manner. Transwell assay indicated that cdc42 partially reversed the effect of miR-186 mimics. Besides, miR-186 was proved to regulate EMT by influencing biomarkers of this process and cell adhesion ability. Thus, miR-186 is a potential target for NSCLC therapy. miR-186 is proposed to be one of tumor-suppressors and may serve as a therapeutic target in NSCLC treatment. PMID:28317368

  5. Bulk production and evaluation of high specific activity 186g Re for cancer therapy using enriched 186 WO 3 targets in a proton beam

    DOE PAGES

    Mastren, Tara; Radchenko, Valery; Bach, Hong T.; ...

    2017-06-01

    Rhenium-186 g (t1/2 = 3.72 d) is a β– emitting isotope suitable for theranostic applications. Current production methods rely on reactor production by way of the reaction 185Re(n,γ)186gRe, which results in low specific activities limiting its use for cancer therapy. Production via charged particle activation of enriched 186W results in a 186gRe product with a much specific activity, allowing it to be used more broadly for targeted radiotherapy applications. Furthermore, this targets the unmet clinical need for more efficient radiotherapeutics.

  6. Bulk production and evaluation of high specific activity 186gRe for cancer therapy using enriched 186WO3 targets in a proton beam

    DOE PAGES

    Mastren, Tara; Radchenko, Valery; Bach, Hong Thu; ...

    2017-03-03

    Rhenium-186 g (t1/2 = 3.72 d) is a β– emitting isotope suitable for theranostic applications. Current production methods rely on reactor production by way of the reaction 185Re(n,γ)186gRe, which results in low specific activities limiting its use for cancer therapy. Production via charged particle activation of enriched 186W results in a 186gRe product with a much specific activity, allowing it to be used more broadly for targeted radiotherapy applications. Furthermore, this targets the unmet clinical need for more efficient radiotherapeutics.

  7. miR186 suppresses prostate cancer progression by targeting Twist1

    PubMed Central

    Deng, Rong; Zhang, Hailong; Dou, Jinzhuo; Yuan, Haihua; Hou, Guofang; Du, Yuzhang; Chen, Qin; Yu, Jianxiu

    2016-01-01

    Prostate cancer (PCa) is the second leading cause of cancer-related deaths in north American men, and most its related deaths are due to advanced and metastatic PCa. However, the molecular mechanisms underlying PCa progression are still unclear. Here we use a pair of prostate cell lines P69/M12, which have the same genetic background and the highly metastatic cell line M12 is a subline derived from P69, to identify the pathogenesis of PCa. We find that a key miRNA--miR186 is significantly reduced in M12 compared to that in P69. Further, we validate that miR186 is also downregulated in human PCa specimens, most significantly in the metastatic patient specimens. The low miR186 expression is correlated with poor patient survival. Through knockdown or overexpression of miR186 in PCa cell lines, we discover that miR186 strongly inhibits cell motility, invasive, soft-agar colony formation, 3D culture growth and vasculogenic mimicry (VM) formation capacity, as well as the epithelial-to-mesenchymal transition (EMT) process by downregulation of its target Twist1. Moreover, the inverse relationship between the expression levels of miR186 and Twist1 is confirmed in vivo tumor metastasis experiment and clinical specimens. Taken together, our findings demonstrate an important role of miR186/Twist1 axis in the regulation of PCa progression, suggesting a potential application of miR186/Twist1 in PCa treatment. PMID:27121312

  8. The concentration and isotopic composition of osmium in the oceans

    SciTech Connect

    Sharma, M.; Papanastassiou, D.A.; Wasserburg, G.J.

    1997-08-01

    Osmium is one of the rarer elements in seawater. Analytical difficulties have previously prevented the direct measurement of the osmium concentration and isotopic composition in seawater. We report a chemical separation procedure that yields quantitative extraction of osmium standard and of osmium tracer by iron hydroxide precipitation from seawater doped with osmium standard, osmium tracer, and FeCl{sub 3}. The iron hydroxide precipitate is processed to extract osmium, using techniques developed for iron meteorites. Utilizing this procedure, water samples from the Pacific and Atlantic oceans were analyzed for osmium concentration and isotopic composition. Direct determination of the osmium concentration of seawater gives between 15 and 19 fM kg{sup -1}. Detailed experiments on different aliquots of one seawater sample from the North Atlantic Ocean, keeping the amounts of reagents constant, yield concentrations from 16 to 19 fM kg{sup -1}. The variability in concentration is outside the uncertainty introduced because of blanks and indicates a lack of full equilibration between the osmium tracer and seawater osmium. The most reliable osmium concentration of the North Atlantic deep ocean water is 19 fM kg {sup -1} with the {sup 187}Os/{sup 186}Os ratio being 8.7{+-}2 (2{sigma}). Detailed experiments on one seawater sample from the Central Pacific Ocean indicate that the most reliable osmium concentration of the deep ocean water from the Central Pacific is 19 fM kg{sup -1} with the {sup 187}Os/{sup 186}Os ratio being 8.7{+-}0.3 (2{sigma}). The directly measured osmium isotopic composition of the oceans is in good agreement with that obtained from the analysis of some rapidly accumulating organic rich sediments. A sample of ambient seawater around the Juan de Fuca Ridge gave {sup 187}Os/{sup 186}Os = 6.9{+-} 0.4. 42 refs., 6 figs., 4 tabs.

  9. Bidentate ligands on osmium(VI) nitrido complexes control intracellular targeting and cell death pathways.

    PubMed

    Suntharalingam, Kogularamanan; Johnstone, Timothy C; Bruno, Peter M; Lin, Wei; Hemann, Michael T; Lippard, Stephen J

    2013-09-25

    The cellular response evoked by antiproliferating osmium(VI) nitrido compounds of general formula OsN(N^N)Cl3 (N^N = 2,2'-bipyridine 1, 1,10-phenanthroline 2, 3,4,7,8-tetramethyl-1,10-phenanthroline 3, or 4,7-diphenyl-1,10-phenanthroline 4) can be tuned by subtle ligand modifications. Complex 2 induces DNA damage, resulting in activation of the p53 pathway, cell cycle arrest at the G2/M phase, and caspase-dependent apoptotic cell death. In contrast, 4 evokes endoplasmic reticulum (ER) stress leading to the upregulation of proteins of the unfolded protein response pathway, increase in ER size, and p53-independent apoptotic cell death. To the best of our knowledge, 4 is the first osmium compound to induce ER stress in cancer cells.

  10. National Ignition Facility subsystem design requirements target area auxiliary subsystem SSDR 1.8.6

    SciTech Connect

    Reitz, T.

    1996-10-20

    This Subsystem Design Requirement (SSDR) establishes the performance, design, development, and test requirements for the Target Area Auxiliary Subsystems (WBS 1.8.6), which is part of the NIF Target Experimental System (WBS 1.8). This document responds directly to the requirements detailed in NIF Target Experimental System SDR 003 document. Key elements of the Target Area Auxiliary Subsystems include: WBS 1.8.6.1 Local Utility Services; WBS 1.8.6.2 Cable Trays; WBS 1.8.6.3 Personnel, Safety, and Occupational Access; WBS 1.8.6.4 Assembly, Installation, and Maintenance Equipment; WBS 1.8.6.4.1 Target Chamber Service System; WBS 1.8.6.4.2 Target Bay Service Systems.

  11. Towards Water Soluble Mitochondria-Targeting Theranostic Osmium(II) Triazole-Based Complexes.

    PubMed

    Omar, Salem A E; Scattergood, Paul A; McKenzie, Luke K; Bryant, Helen E; Weinstein, Julia A; Elliott, Paul I P

    2016-10-18

    The complex [Os(btzpy)₂][PF₆]₂ (1, btzpy = 2,6-bis(1-phenyl-1,2,3-triazol-4-yl)pyridine) has been prepared and characterised. Complex 1 exhibits phosphorescence (λem = 595 nm, τ = 937 ns, φem = 9.3% in degassed acetonitrile) in contrast to its known ruthenium(II) analogue, which is non-emissive at room temperature. The complex undergoes significant oxygen-dependent quenching of emission with a 43-fold reduction in luminescence intensity between degassed and aerated acetonitrile solutions, indicating its potential to act as a singlet oxygen sensitiser. Complex 1 underwent counterion metathesis to yield [Os(btzpy)₂]Cl₂ (1(Cl)), which shows near identical optical absorption and emission spectra to those of 1. Direct measurement of the yield of singlet oxygen sensitised by 1(Cl) was carried out (φ (¹O₂) = 57%) for air equilibrated acetonitrile solutions. On the basis of these photophysical properties, preliminary cellular uptake and luminescence microscopy imaging studies were conducted. Complex 1(Cl) readily entered the cancer cell lines HeLa and U2OS with mitochondrial staining seen and intense emission allowing for imaging at concentrations as low as 1 μM. Long-term toxicity results indicate low toxicity in HeLa cells with LD50 >100 μM. Osmium(II) complexes based on 1 therefore present an excellent platform for the development of novel theranostic agents for anticancer activity.

  12. A novel Osmium-based compound targets the mitochondria and triggers ROS-dependent apoptosis in colon carcinoma.

    PubMed

    Maillet, A; Yadav, S; Loo, Y L; Sachaphibulkij, K; Pervaiz, S

    2013-06-06

    Engagement of the mitochondrial-death amplification pathway is an essential component in chemotherapeutic execution of cancer cells. Therefore, identification of mitochondria-targeting agents has become an attractive avenue for novel drug discovery. Here, we report the anticancer activity of a novel Osmium-based organometallic compound (hereafter named Os) on different colorectal carcinoma cell lines. HCT116 cell line was highly sensitive to Os and displayed characteristic features of autophagy and apoptosis; however, inhibition of autophagy did not rescue cell death unlike the pan-caspase inhibitor z-VAD-fmk. Furthermore, Os significantly altered mitochondrial morphology, disrupted electron transport flux, decreased mitochondrial transmembrane potential and ATP levels, and triggered a significant increase in reactive oxygen species (ROS) production. Interestingly, the sensitivity of cell lines to Os was linked to its ability to induce mitochondrial ROS production (HCT116 and RKO) as HT29 and SW620 cell lines that failed to show an increase in ROS were resistant to the death-inducing activity of Os. Finally, intra-peritoneal injections of Os significantly inhibited tumor formation in a murine model of HCT116 carcinogenesis, and pretreatment with Os significantly enhanced tumor cell sensitivity to cisplatin and doxorubicin. These data highlight the mitochondria-targeting activity of this novel compound with potent anticancer effect in vitro and in vivo, which could have potential implications for strategic therapeutic drug design.

  13. MicroRNA-186 targets Yes-associated protein 1 to inhibit Hippo signaling and tumorigenesis in hepatocellular carcinoma.

    PubMed

    Ruan, Tingyan; He, Xiaoting; Yu, Jun; Hang, Zhiqiang

    2016-04-01

    Liver cancer, particularly hepatocellular carcinoma (HCC), is one of leading causes of cancer-related mortality worldwide. Upregulation of the evolutionary conserved Hippo signaling pathway has been observed in HCC patients, and Yes-associated protein 1 (YAP1) has been reported to play a key role in HCC tumorigenesis. microRNAs (miRNAs) are a family of small non-coding RNAs, usually 21-25 nucleotides in length, and are essential in the regulation of gene expression. Abnormal miRNA expression has been implicated in the initiation and progression of numerous forms of cancers, including liver cancer. Here, we report the identification of a novel miRNA, miR-186, and its functions as an HCC tumor suppressor. We observed that miR-186 was downregulated in several HCC cell lines, and that it directly targets YAP1 mRNA. Overexpression of miR-186 in HCC cells significantly downregulates YAP1 mRNA and protein levels, leading to downregulation of the Hippo signaling pathway, which in turn severely inhibits HCC cell migration, invasion and proliferation. Our study is the first to report the direct involvement of miR-186 in downregulating YAP1 and, more significantly, inhibiting HCC tumorigenesis, and supports the role miR-186 as a potential therapeutic target in treating liver cancer.

  14. The concentration and isotopic composition of osmium in the oceans

    NASA Astrophysics Data System (ADS)

    Sharma, M.; Papanastassiou, D. A.; Wasserburg, G. J.

    1997-08-01

    Osmium is one of the rarer elements in seawater. Analytical difficulties have previously prevented the direct measurement of the osmium concentration and isotopic composition in seawater. We report a chemical separation procedure that yields quantitative extraction of osmium standard and of osmium tracer by iron hydroxide precipitation from seawater doped with osmium standard, osmium tracer, and FeCl 3. The iron hydroxide precipitate is processed to extract osmium, using techniques developed for iron meteorites. Utilizing this procedure, water samples from the Pacific and Atlantic oceans were analyzed for osmium concentration and isotopic composition. Direct determination of the osmium concentration of seawater gives between 15 and 19 fM kg -1. Detailed experiments on different aliquots of one seawater sample from the North Atlantic Ocean, keeping the amounts of reagents constant, yield concentrations from 16 to 19 fM kg -1. The variability in concentration is outside the uncertainty introduced because of blanks and indicates a lack of full equilibration between the osmium tracer and seawater osmium. The most reliable osmium concentration of the North Atlantic deep ocean water is 19 fM kg -1 with the 187Os 186Os ratio being 8.7 ± 0.2 (2σ). Detailed experiments on one seawater sample from the Central Pacific Ocean indicate that the most reliable osmium concentration of the deep ocean water from the Central Pacific is 19 fM kg -1 with the 187Os 186Os ratio being 8.7 ± 0.3 (2σ). The directly measured osmium isotopic composition of the oceans is in good agreement with that obtained from the analysis of some rapidly accumulating organic rich sediments ( Ravizza and Turekian, 1992). A sample of ambient seawater around the Juan de Fuca Ridge gave 187Os 186Os= 6.9 ± 0.4. This is distinctly lower than the deep-sea water value and may reflect local hydrothermal activity or some analytical difficulty with this sample. The osmium isotopic composition of the deep oceans

  15. Deuteron irradiation of W and WO3 for production of high specific activity 186Re: Challenges associated with thick target preparation

    DOE PAGES

    Balkin, Ethan R.; Gagnon, Katherine; Strong, Kevin T.; ...

    2016-06-28

    This investigation evaluated target fabrication and beam parameters for scale-up production of high specific activity 186Re using deuteron irradiation of enriched 186W via the 186W(d,2n)186Re reaction. Thick W and WO3 targets were prepared, characterized and evaluated in deuteron irradiations. Full-thickness targets, as determined using SRIM, were prepared by uniaxi-ally pressing powdered natural abundance W and WO3, or 96.86% enriched 186W, into Al target supports. Alternatively, thick targets were prepared by pressing 186W between two layers of graphite powder or by placing pre-sintered (1105°C, 12 hours) natural abundance WO3 pellets into an Al target support. Assessments of structural integrity were mademore » on each target pre-pared. Prior to irradiation, material composition analyses were conducted using SEM, XRD, and Raman spectroscopy. With-in a minimum of 24 hours post irradiation, gamma-ray spectroscopy was performed on all targets to assess production yields and radionuclidic byproducts. Problems were encountered with the structural integrity of some pressed W and WO3 pellets before and during irradiation, and target material characterization results could be correlated with the structural integrity of the pressed target pellets. Under the conditions studied, the findings suggest that all WO3 targets prepared and studied were unacceptable. By contrast, 186W metal was found to be a viable target material for 186Re production. Lastly, thick targets prepared with powdered 186W pressed between layers of graphite provided a particularly robust target configuration.« less

  16. Deuteron irradiation of W and WO3 for production of high specific activity 186Re: Challenges associated with thick target preparation

    SciTech Connect

    Balkin, Ethan R.; Gagnon, Katherine; Strong, Kevin T.; Smith, Bennett E.; Dorman, Eric F.; Emery, Robert C.; Pauzauskie, Peter J.; Fassbender, Michael E.; Cutler, Cathy S.; Ketring, Alan R.; Jurisson, Silvia S.; Wilbur, D. Scott

    2016-06-28

    This investigation evaluated target fabrication and beam parameters for scale-up production of high specific activity 186Re using deuteron irradiation of enriched 186W via the 186W(d,2n)186Re reaction. Thick W and WO3 targets were prepared, characterized and evaluated in deuteron irradiations. Full-thickness targets, as determined using SRIM, were prepared by uniaxi-ally pressing powdered natural abundance W and WO3, or 96.86% enriched 186W, into Al target supports. Alternatively, thick targets were prepared by pressing 186W between two layers of graphite powder or by placing pre-sintered (1105°C, 12 hours) natural abundance WO3 pellets into an Al target support. Assessments of structural integrity were made on each target pre-pared. Prior to irradiation, material composition analyses were conducted using SEM, XRD, and Raman spectroscopy. With-in a minimum of 24 hours post irradiation, gamma-ray spectroscopy was performed on all targets to assess production yields and radionuclidic byproducts. Problems were encountered with the structural integrity of some pressed W and WO3 pellets before and during irradiation, and target material characterization results could be correlated with the structural integrity of the pressed target pellets. Under the conditions studied, the findings suggest that all WO3 targets prepared and studied were unacceptable. By contrast, 186W metal was found to be a viable target material for 186Re production. Lastly, thick targets prepared with powdered 186W pressed between layers of graphite provided a particularly robust target configuration.

  17. Ligand-incorporation site in 5-methylcytosine-detection probe modulating the site of osmium complexation with the target DNA.

    PubMed

    Sugizaki, Kaori; Nakamura, Akiko; Yanagisawa, Hiroyuki; Okamoto, Akimitsu

    2012-09-01

    ICON Probes, short DNA strands containing an adenine linked to a bipyridine ligand, formed an interstrand cross-link with 5-methylcytosine located opposite the modified adenine in the presence of an osmium oxidant. The location of a bipyridine-tethered adenine in the probes varied the selectivity of the reactive base. An ICON probe where the modified adenine was located at the probe center showed a 5-methylcytosine-selective osmium complexation, whereas an ICON probe with the modified adenine at the strand end exhibited high reactivity towards thymine as well as 5-methylcytosine. The modulation of reactive bases by the incorporation of a bipyridine-tethered adenine site made facilitates design of ICON probes for the fluorometric detection of 5-methylcytosine.

  18. Development of anticancer agents: wizardry with osmium.

    PubMed

    Hanif, Muhammad; Babak, Maria V; Hartinger, Christian G

    2014-10-01

    Platinum compounds are one of the pillars of modern cancer chemotherapy. The apparent disadvantages of existing chemotherapeutics have led to the development of novel anticancer agents with alternative modes of action. Many complexes of the heavy metal osmium (Os) are potent growth inhibitors of human cancer cells and are active in vivo, often superior or comparable to cisplatin, as the benchmark metal-based anticancer agent, or clinically tested ruthenium (Ru) drug candidates. Depending on the choice of ligand system, osmium compounds exhibit diverse modes of action, including redox activation, DNA targeting or inhibition of protein kinases. In this review, we highlight recent advances in the development of osmium anticancer drug candidates and discuss their cellular mechanisms of action.

  19. Contactin-1 and Neurofascin-155/-186 Are Not Targets of Auto-Antibodies in Multifocal Motor Neuropathy.

    PubMed

    Doppler, Kathrin; Appeltshauser, Luise; Krämer, Heidrun H; Ng, Judy King Man; Meinl, Edgar; Villmann, Carmen; Brophy, Peter; Dib-Hajj, Sulayman D; Waxman, Stephen G; Weishaupt, Andreas; Sommer, Claudia

    2015-01-01

    Multifocal motor neuropathy is an immune mediated disease presenting with multifocal muscle weakness and conduction block. IgM auto-antibodies against the ganglioside GM1 are detectable in about 50% of the patients. Auto-antibodies against the paranodal proteins contactin-1 and neurofascin-155 and the nodal protein neurofascin-186 have been detected in subgroups of patients with chronic inflammatory demyelinating polyneuropathy. Recently, auto-antibodies against neurofascin-186 and gliomedin were described in more than 60% of patients with multifocal motor neuropathy. In the current study, we aimed to validate this finding, using a combination of different assays for auto-antibody detection. In addition we intended to detect further auto-antibodies against paranodal proteins, specifically contactin-1 and neurofascin-155 in multifocal motor neuropathy patients' sera. We analyzed sera of 33 patients with well-characterized multifocal motor neuropathy for IgM or IgG anti-contactin-1, anti-neurofascin-155 or -186 antibodies using enzyme-linked immunosorbent assay, binding assays with transfected human embryonic kidney 293 cells and murine teased fibers. We did not detect any IgM or IgG auto-antibodies against contactin-1, neurofascin-155 or -186 in any of our multifocal motor neuropathy patients. We conclude that auto-antibodies against contactin-1, neurofascin-155 and -186 do not play a relevant role in the pathogenesis in this cohort with multifocal motor neuropathy.

  20. Osmium Recycling in Subduction Zones

    PubMed

    Brandon; Creaser; Shirey; Carlson

    1996-05-10

    Peridotite xenoliths from the Cascade arc in the United States and in the Japan arc have neodymium and osmium isotopic compositions that are consistent with addition of 5 to 15 percent of subducted material to the present-day depleted mantle. These observations suggest that osmium can be partitioned into oxidized and chlorine-rich slab-derived fluids or melts. These results place new constraints on the behavior of osmium (and possibly other platinum group elements) during subduction of oceanic crust by showing that osmium can be transported into the mantle wedge.

  1. Applications of the 190Pt-186Os isotope system to geochemistry and cosmochemistry

    USGS Publications Warehouse

    Walker, R.J.; Morgan, J.W.; Beary, E.S.; Smoliar, M.I.; Czamanske, G.K.; Horan, M.F.

    1997-01-01

    Platinum is fractionated from osmium primarily as a consequence of processes involving sulfide and metal crystallization. Consequently, the 190Pt-186Os isotope system (190Pt ??? 186Os + ??) shows promise for dating some types of magmatic sulfide ores and evolved iron meteorites. The first 190Pt-186Os isochrons are presented here for ores from the ca. 251 Ma Noril'sk, Siberia plume, and for group IIAB magmatic iron meteorites. Given the known age of the Noril'sk system, a decay constant for 190Pt is determined to be 1.542 ?? 10-12a-1, with ??1% uncertainty. The isochron generated for the IIAB irons is consistent with this decay constant and the known age of the group. The 186Os/188Os ratios of presumably young, mantle-derived osmiridiums and also the carbonaceous chondrite Allende were measured to high-precision to constrain the composition of the modern upper mantle. These compositions overlap, indicating that the upper mantle is chondritic within the level of resolution now available. Our best estimate for this 186Os/188Os ratio is 0.119834 ?? 2 (2??M). The 190Pt/186Os ratios determined for six enstatite chondrites average 0.001659 ?? 75, which is very similar to published values for carbonaceous chondrites. Using this ratio and the presumed composition of the modern upper mantle and chondrites, a solar system initial 186Os/188Os ratio of 0.119820 is calculated. In comparison to the modern upper mantle composition, the 186Os/188Os ratio of the Noril'sk plume was approximately 0.012% enriched in 186Os. Possible reasons for this heterogeneity include the recycling of Pt-rich crust into the mantle source of the plume and derivation of the osmium from the outer core. Derivation of the osmium from the outer core is our favored model. Copyright ?? 1997 Elsevier Science Ltd.

  2. New method for the measurement of osmium isotopes applied to a New Zealand Cretaceous/Tertiary boundary shale

    USGS Publications Warehouse

    Lichte, F.E.; Wilson, S.M.; Brooks, R.R.; Reeves, R.D.; Holzbecher, J.; Ryan, D.E.

    1986-01-01

    The determination of osmium content and isotopic abundances in geological materials has received increasing attention in recent years following the proposal of Alvarez et al.1 that mass extinctions at the end of the Cretaceous period were caused by the impact of a large (???10km) meteorite which left anomalously high iridium levels as a geochemical signature in the boundary shales. Here we report a new and simple method for measuring osmium in geological materials, involving fusion of the sample with sodium peroxide, distillation of the osmium as the tetroxide using perchloric acid, extraction into chloroform, and absorption of the chloroform extract onto graphite powder before instrumental neutron activation analysis. In a variant of this technique, the chloroform extract is back-extracted into an aqueous phase and the osmium isotopes are determined by plasma-source mass spectrometry (ICPMS). We have used this method on the Woodside Creek (New Zealand) Cretaceous/Tertiary boundary clay and have obtained the first osmium content (6g ng g-1) for this material. The 187Os/186Os ratio is 1.12??0.16, showing a typical non-crustal signature. This combined distillation-extraction- ICPMS method will prove to be useful for measuring osmium isotopes in other geological materials. ?? 1986 Nature Publishing Group.

  3. An osmium-DNA interstrand complex: application to facile DNA methylation analysis.

    PubMed

    Tanaka, Kazuo; Tainaka, Kazuki; Umemoto, Tadashi; Nomura, Akiko; Okamoto, Akimitsu

    2007-11-21

    Nucleic acids often acquire new functions by forming a variety of complexes with metal ions. Osmium, in an oxidized state, also reacts with C5-methylated pyrimidines. However, control of the sequence specificity of osmium complexation with DNA is still immature, and the value of the resulting complexes is unknown. We have designed a bipyridine-attached adenine derivative for sequence-specific osmium complexation. Sequence-specific osmium complexation was achieved by hybridization of a short DNA molecule containing this functional nucleotide to a target DNA sequence and resulted in the formation of a cross-linked structure. The interstrand cross-link clearly distinguished methylated cytosines from unmethylated cytosines and was used to quantify the degree of methylation at a specific cytosine in the genome.

  4. The causes for geographical variations in OS187/OS186 at the Cretaceous-Tertiary boundary

    NASA Technical Reports Server (NTRS)

    Turekian, K. K.; Esser, B. K.; Ravizza, G. E.

    1988-01-01

    Researchers at Yale has approached the problem of the osmium isotopic composition of marine deposits formed in contact with both oxidized and reduced bottom waters. The measured (187) Os/(186) Os ratios of modern bulk sediment can be explained using mixing equations involving continental detrital, volcaniclastic, cosmogenic and hydrogeneous components. These studies show that sediments deposited under reducing marine conditions contain a hydrogenous component which is enriched in Re and has a radiogenic (187) Os/(186) Os ratio. The presence of such a hydrogenous component in the marine fish clay at Stevns Klint can account for the elevation of its (187) Os/(186) Os ration above the expected meteoritic value. Mass balance considerations require the Re/Os ratio of the phase precipitated from the terminal Cretaceous sea at Stevns Klint to have been about one tenth the value observed in contemporary deposits in the Black Sea, assuming Re has not been lost (or Os gained) subsequent to precipitation. In continental sections, the elevation of the (187) Os/(186) Os ratio in boundary layers may be due to precipitation from continental waters of crustally-derived radiogenic osmium either contemporaneous with the meteoritic (or mantle) osmium deposition or later during diagenesis.

  5. New osmium-based reagent for the dihydroxylation of alkenes.

    PubMed

    Donohoe, Timothy J; Harris, Robert M; Butterworth, Sam; Burrows, Jeremy N; Cowley, Andrew; Parker, Jeremy S

    2006-06-09

    The cis dihydroxylation of alkenes is most efficiently accomplished by reaction with osmium tetroxide. Recently, the expense and toxicity of osmium tetroxide have led to a number of attempts to harness alternative osmium-based reagents, including microencapsulation and solid support techniques. We describe here the development of a new nonvolatile, stable, and recoverable osmium-based reagent devised for the stoichiometric cis dihydroxylation of alkenes. Although attempts to make this new dihydroxylation work with catalytic amounts of this reagent were unsuccessful, we did develop a sensitive test for free osmium tetroxide leached from the reagent in situ: this test may well have uses in probing future applications of derivatized osmium reagents.

  6. Microencapsulation of osmium tetroxide in polyurea.

    PubMed

    Ley, Steven V; Ramarao, Chandrashekar; Lee, Ai-Lan; Østergaard, Niels; Smith, Stephen C; Shirley, Ian M

    2003-01-23

    [reaction: see text] Osmium tetroxide has been microencapsulated in a polyurea matrix using an in situ interfacial polymerization approach. These microcapsules have been effectively used as recoverable and reusable catalysts in the dihydroxylation of olefins

  7. Rhenium-osmium isotope systematics of carbonaceous chondrites

    USGS Publications Warehouse

    Walker, R.J.; Morgan, J.W.

    1989-01-01

    Rhenium and osmium concentrations and Os isotopic compositions of eight carbonaceous chondrites, one LL3 ordinary chondrite, and two iron meteorites were determined by resonance ionization mass spectrometry. Iron meteorite 187Re/186Os and 187OS/186Os ratios plot on the previously determined iron meteorite isochron, but most chondrite data plot 1 to 2 percent above this meteorite isochron. This suggests either that irons have significantly younger Re-Os closure ages than chondrites or that chondrites were formed from precursor materials with different chemical histories from the precursors of irons. Some samples of Semarkona (LL3) and Murray (C2M) meteorites plot 4 to 6 percent above the iron meteorite isochron, well above the field delineated by other chondrites. Murray may have lost Re by aqueous leaching during its preterrestrial history. Semarkona could have experienced a similar loss of Re, but only slight aqueous alteration is evident in the meteorite. Therefore, the isotopic composition of Semarkona could reflect assembly of isotopically heterogeneous components subsequent to 4.55 billion years ago or Os isotopic heterogeneities in the primordial solar nebula.

  8. Antagonizing STAT5B dimerization with an osmium complex

    PubMed Central

    Liu, Li-Juan; Wang, Wanhe; Kang, Tian-Shu; Liang, Jia-Xin; Liu, Chenfu; Kwong, Daniel W. J.; Wong, Vincent Kam Wai; Ma, Dik-Lung; Leung, Chung-Hang

    2016-01-01

    Targeting STAT5 is an appealing therapeutic strategy for the treatment of hematologic malignancies and inflammation. Here, we present the novel osmium(II) complex 1 as the first metal-based inhibitor of STAT5B dimerization. Complex 1 exhibited superior inhibitory activity against STAT5B DNA binding compared to STAT5A DNA binding. Moreover, 1 repressed STAT5B transcription and blocked STAT5B dimerization via binding to the STAT5B protein, thereby inhibiting STAT5B translocation to the nucleus. Furthermore, 1 was able to selectively inhibit STAT5B phosphorylation without affecting the expression level of STAT5B. PMID:27853239

  9. Osmium isotopes in Ivory Coast tektites: Confirmation of a meteoritic component and rhenium depletion

    NASA Technical Reports Server (NTRS)

    Koeberl, Christian; Shirey, Steven B.

    1993-01-01

    The sensitive negative thermal ionization mass spectrometry method was used for the measurement of concentrations and isotopic ratios of osmium and rhenium in four Ivory Coast tektites. These tektites have crustal major and trace element composition, as well as large negative epsilon(sub Nd)(-20) and positive epsilon(sub Sr)(+260 to +300) which are characteristic for old continental crust. Os concentrations ranging from 0.09 to 0.30 ppb were found, clearly much higher than average crustal values, Os-187/Os-186 ratios of about 1.2-1.7, and low Re-187/Os-186 ratios. These results show unambiguously the existence of a meteoritic component (on the order of 0.06%) in the Ivory Coast tektites. Low Re abundances are the result of fractionation of Re during the impact.

  10. Osmium-191/iridium-191m radionuclide

    DOEpatents

    Knapp, Jr., Furn F.; Butler, Thomas A.; Brihaye, Claude

    1987-01-01

    A generator system to provide iridium-191m for clinical imaging applications comprises an activated carbon adsorbent loaded with a compound containing the parent nuclide, osmium-191. The generator, which has a shelf-life in excess of two weeks and does not require a scavenger column, can be eluted with physiologically compatible saline.

  11. Osmium-191/iridium-191m radionuclide

    DOEpatents

    Knapp, F.F. Jr.; Butler, T.A.; Brihaye, C.

    1985-08-26

    A generator system to provide iridium-191m for clinical imaging applications comprises an activated carbon adsorbent loaded with a compound containing the parent nuclide, osmium-191. The generator, which has a shelf-life in excess of two weeks and does not require a scavenger column, can be eluted with physiologically compatible saline. 4 figs. 3 tabs.

  12. DNA-osmium complexes: recent developments in the operative chemical analysis of DNA epigenetic modifications.

    PubMed

    Okamoto, Akimitsu

    2014-09-01

    The development of a reaction for the detection of one epigenetic modification in a long DNA strand is a chemically and biologically challenging research subject. Herein, we report and discuss the formation of 5-methylcytosine-osmium complexes that are used as the basis for a bisulfite-free chemical assay for DNA methylation analysis. Osmium in the oxidized state reacts with C5-methylated pyrimidines in the presence of a bipyridine ligand to give a stable ternary complex. On the basis of this reaction, an adenine derivative with a tethered bipyridine moiety has been designed for sequence-specific osmium complex formation. Osmium complexation is then achieved by hybridization of a short DNA molecule containing this functional nucleotide to a target DNA sequence and results in the formation of a cross-linked structure. This novel concept of methylation-specific reaction, based on a straightforward chemical process, expands the range of methods available for the analysis of epigenetic modifications. Advantages of the described method include amplification-insensitive detection, 5-hydroxymethylcytosine complexation, and visualization through methylation-specific in situ hybridization.

  13. Rhenium-osmium isotope systematics of carbonaceous chondrites.

    PubMed

    Walker, R J; Morgan, J W

    1989-01-27

    Rhenium and osmium concentrations and Os isotopic compositions of eight carbonaceous chondrites, one LL3 ordinary chondrite, and two iron meteorites were determined by resonance ionization mass spectrometry. Iron meteorite (187)Re/(186)Os and (l87)Os/(l86)Os ratios plot on the previously determined iron meteorite isochron, but most chondrite data plot 1 to 2 percent above this meteorite isochron. This suggests either that irons have significantly younger Re-Os closure ages than chondrites or that chondrites were formed from precursor materials with different chemical histories from the precursors of irons. Some samples of Semarkona (LL3) and Murray (C2M) meteorites plot 4 to 6 percent above the iron meteorite isochron, well above the field delineated by other chondrites. Murray may have lost Re by aqueous leaching during its preterrestrial history. Semarkona could have experienced a similar loss of Re, but only slight aqueous alteration is evident in the meteorite. Therefore, the isotopic composition of Semarkona could reflect assembly of isotopically heterogeneous components subsequent to 4.55 billion years ago or Os isotopic heterogeneities in the primordial solar nebula.

  14. Osmium complex binding to mismatched methylcytosine: effect of adjacent bases.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-01-01

    We investigated the efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes depended on the 5'-neighboring base of the 5-methylcytosine. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique side reaction was observed. However, the mismatched base pairs did not influence the selectivity of osmium complexation with methylated DNA.

  15. Osmium isotopes and silver as tracers of anthropogenic metals in sediments from Massachusetts and Cape Cod bays

    USGS Publications Warehouse

    Ravizza, G.E.; Bothner, Michael H.

    1996-01-01

    High concentrations of osmium (Os) and silver (Ag) and low 187Os/186Os ratios in Boston sewage make these elements sensitive tracers of the influence of sewage on marine sediments in Massachusetts and Cape Cod bays. Pristine marine sediments have Ag concentrations more than 200 times lower than sewage sludge, Os concentrations 10-40 times lower, and 187Os/186Os ratios six times higher. Surface sediments from both Massachusetts and Cape Cod bays exhibit both high Ag concentrations and low 187Os/186Os ratios indicating the influence of sewage particles on marine sediments in this region extends some 70 km from the point of sewage release. In detail, the distribution of Os and Ag do not support a model of simple physical mixing of sewage particles with normal marine sediments. Deviations from the mixing model may be the result of fractionation of Os and Ag in the marine environment, and [or] independent temporal variations in the Os and Ag content of the waste stream. The results of this investigation suggest that osmium isotopes may be widely applicable as tracers of the influence of sewage on sediments in estuarine environments and that subtle variations in the isotopic composition of Os in the waste stream may help constrain the sources of Os and other metals delivered to the environment.

  16. Osmium isotopes and silver as tracers of anthropogenic metals in sediments from Massachusetts and Cape Cod bays

    NASA Astrophysics Data System (ADS)

    Ravizza, G. E.; Bothner, M. H.

    1996-08-01

    High concentrations of osmium (Os) and silver (Ag) and low 187Os/ 186Os ratios in Boston sewage make these elements sensitive tracers of the influence of sewage on marine sediments in Massachusetts and Cape Cod bays. Pristine marine sediments have Ag concentrations more than 200 times lower than sewage sludge, Os concentrations 10-40 times lower, and 187OS/ 186Os ratios six times higher. Surface sediments from both Massachusetts and Cape Cod bays exhibit both high Ag concentrations and low 187OS/ 186Os ratios indicating the influence of sewage particles on marine sediments in this region extends some 70 km from the point of sewage release. In detail, the distribution of Os and Ag do not support a model of simple physical mixing of sewage particles with normal marine sediments. Deviations from the mixing model may be the result of fractionation of Os and Ag in the marine environment, and [or] independent temporal variations in the Os and Ag content of the waste stream. The results of this investigation suggest that osmium isotopes may be widely applicable as tracers of the influence of sewage on sediments in estuarine environments and that subtle variations in the isotopic composition of Os in the waste stream may help constrain the sources of Os and other metals delivered to the environment.

  17. The role of lysine 186 in HIV-1 integrase multimerization

    SciTech Connect

    Berthoux, Lionel; Sebastian, Sarah; Muesing, Mark A.; Luban, Jeremy . E-mail: luban@irb.unisi.ch

    2007-07-20

    HIV-1 integrase (IN) catalyzes biochemical reactions required for viral cDNA insertion into host cell chromosomal DNA, an essential step in the HIV-1 replication cycle. In one of these reactions, the two ends of the linear viral cDNA are believed to be simultaneously ligated to chromosomal DNA by a tetrameric form of IN. The structure of the full-length IN tetramer is not known but a model consisting of the N-terminal domain and the catalytic core revealed basic residues 186 to 188 at the interface between the two IN dimers. We found that alteration of these residues, in particular changing IN lysine residue 186 to glutamate (K186Q), impairs IN oligomerization in the yeast two-hybrid system and decreases oligomeric forms of IN within virions. When expressed independently of other viral proteins in human cells, IN-K186Q did not concentrate in the nucleus as did wild-type IN. Co-expression of wild-type IN restored the multimerization defects of IN-K186Q, in both the two-hybrid system and in virions, and also rescued the nuclear targeting defects. Virions bearing IN-K186Q were not infectious in a single cycle of replication but when mixed virions containing two different IN mutants were produced, IN-K186Q was capable of complementing the catalytically inactive mutant IN-D116A. Our biochemical and functional data support the crystallographic model in which IN residue K186 lies at the interface between IN dimers and suggest that tetramerization is important, not only for concerted integration, but also for IN nuclear targeting.

  18. Anthropogenic forcings on the surficial osmium cycle.

    PubMed

    Rauch, Sebastien; Peucker-Ehrenbrink, Bernhard; Kylander, Malin E; Weiss, Dominik J; Martinez-Cortizas, Antonio; Heslop, David; Olid, Carolina; Mighall, Tim M; Hemond, Harold F

    2010-02-01

    Osmium is among the least abundant elements in the Earth's continental crust. Recent anthropogenic Os contamination of the environment from mining and smelting activities, automotive catalytic converter use, and hospital discharges has been documented. Here we present evidence for anthropogenic overprinting of the natural Os cycle using a ca. 7000-year record of atmospheric Os deposition and isotopic composition from an ombrotrophic peat bog in NW Spain. Preanthropogenic Os accumulation in this area is 0.10 +/- 0.04 ng m(-2) y(-1). The oldest strata showing human influence correspond to early metal mining and processing on the Iberian Peninsula (ca. 4700-2500 cal. BP). Elevated Os accumulation rates are found thereafter with a local maximum of 1.1 ng m(-2) y(-1) during the Roman occupation of the Iberian Peninsula (ca. 1930 cal. BP) and a further increase starting in 1750 AD with Os accumulation reaching 30 ng m(-2) y(-1) in the most recent samples. Osmium isotopic composition ((187)Os/(188)Os) indicates that recent elevated Os accumulation results from increased input of unradiogenic Os from industrial and automotive sources as well as from enhanced deposition of radiogenic Os through increased fossil fuel combustion and soil erosion. We posit that the rapid increase in catalyst-equipped vehicles, increased fossil fuel combustion, and changes in land-use make the changes observed in NW Spain globally relevant.

  19. Anticancer activity of osmium metalla-rectangles.

    PubMed

    Barry, Nicolas P E; Edafe, Fabio; Dyson, Paul J; Therrien, Bruno

    2010-03-21

    A series of cationic metalla-rectangles of the general formula [(p-cymene)(4)Os(4)(OO[intersection]OO)(2)(N[intersection]N)(2)](4+) have been obtained in methanol from the dinuclear arene osmium precursors [(p-cymene)(2)Os(2)(OO[intersection]OO)(2)Cl(2)] (OO[intersection]OO = 2,5-dioxydo-1,4-benzoquinonato (dhbq), 2,5-dichloro-1,4-benzoquinonato (dcbq)) by reaction with bipyridine linkers (N[intersection]N = 4,4'-bipyridine, 1,2-bis(4-pyridyl)ethylene) in the presence of AgCF(3)SO(3). All complexes were isolated as triflate salts and characterised by NMR, IR and UV-visible spectroscopy. The cytotoxicities of the dinuclear and tetranuclear osmium complexes were established using ovarian A2780 cancer cell lines. The most active metalla-rectangle, [(p-cymene)(4)Os(4)(dhbq)(2)(4,4'-bipyridine)(2)](4+), shows an IC(50) value of 5.7 microM (comparable to cisplatin) against A2780 cancer cells and 7.5 microM against the cisplatin resistant A2780cisR cells.

  20. 21 CFR 186.1557 - Tall oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Tall oil. 186.1557 Section 186.1557 Food and Drugs... Substances Affirmed as GRAS § 186.1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap... consists mainly of tall oil resin acids and tall oil fatty acids. (b) In accordance with § 186.1(b)(1),...

  1. 21 CFR 186.1557 - Tall oil.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Tall oil. 186.1557 Section 186.1557 Food and Drugs... Substances Affirmed as GRAS § 186.1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap... consists mainly of tall oil resin acids and tall oil fatty acids. (b) In accordance with § 186.1(b)(1),...

  2. 21 CFR 186.1557 - Tall oil.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Tall oil. 186.1557 Section 186.1557 Food and Drugs... Substances Affirmed as GRAS § 186.1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap... consists mainly of tall oil resin acids and tall oil fatty acids. (b) In accordance with § 186.1(b)(1),...

  3. 21 CFR 186.1557 - Tall oil.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Tall oil. 186.1557 Section 186.1557 Food and Drugs... Substances Affirmed as GRAS § 186.1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap... consists mainly of tall oil resin acids and tall oil fatty acids. (b) In accordance with § 186.1(b)(1),...

  4. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 49 Transportation 7 2013-10-01 2013-10-01 false Abdomen assembly. 572.186 Section 572.186... Test Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000...(e). When subjected to tests procedures specified in paragraph (b) of this section, the...

  5. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Abdomen assembly. 572.186 Section 572.186... Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is...). When subjected to tests procedures specified in paragraph (b) of this section, the abdomen...

  6. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 49 Transportation 7 2014-10-01 2014-10-01 false Abdomen assembly. 572.186 Section 572.186... Test Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000...(e). When subjected to tests procedures specified in paragraph (b) of this section, the...

  7. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 49 Transportation 7 2012-10-01 2012-10-01 false Abdomen assembly. 572.186 Section 572.186... Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is...). When subjected to tests procedures specified in paragraph (b) of this section, the abdomen...

  8. 49 CFR 572.186 - Abdomen assembly.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Abdomen assembly. 572.186 Section 572.186... Dummy, 50th Percentile Adult Male § 572.186 Abdomen assembly. (a) The abdomen assembly (175-5000) is...). When subjected to tests procedures specified in paragraph (b) of this section, the abdomen...

  9. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  10. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  11. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  12. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS Reg. No. 7758-19-2) exists as... solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient is used at levels from 125 to...

  13. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  14. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium sulfate. 186.1797 Section 186.1797 Food and... Substances Affirmed as GRAS § 186.1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6... crystalline powder. It is prepared by the neutralization of sulfuric acid with sodium hydroxide. (b)...

  15. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  16. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium chlorite. 186.1750 Section 186.1750 Food... of Specific Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS... passing chlorine dioxide into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient...

  17. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  18. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  19. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Japan wax. 186.1555 Section 186.1555 Food and... Substances Affirmed as GRAS § 186.1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan... fruits of the oriental sumac, Rhus succedanea (Japan, Taiwan, and Indo-China), R. vernicifera...

  20. Rhenium-osmium and samarium-neodymium isotopic systematics of the stillwater complex

    USGS Publications Warehouse

    Lambert, D.D.; Morgan, J.W.; Walker, R.J.; Shirey, S.B.; Carlson, R.W.; Zientek, M.L.; Koski, M.S.

    1989-01-01

    Isotopic data for the Stillwater Complex, Montana , which formed about 2700 Ma (million years ago), were obtained to evaluate the role of magma mixing in the formation of strategic platinum-group element (PGE) ore deposits. Neodymium and osmium isotopic data indicate that the intrusion formed from at least two geochemically distinct magmas. Ultramafic affinity (U-type) magmas had initial ??Nd of -0.8 to -3.2 and a chondritic initial 187Os/186Os ratio of ???0.88, whereas anorthositic affinity (A-type) magmas had ??Nd of -0.7 to +1.7 and an initial 187Os/186Os ratio of ???1.13. These data suggest that U-type magmas were derived from a lithospheric mantle source containing recycled crustal materials whereas A-type magmas originated either by crustal contamination of basaltic magmas or by partial melting of basalt in the lower crust. The Nd and Os isotopic data also suggest that Os, and probably the other PGEs in ore horizons such as the J-M Reef, was derived from A-type magmas. The Nd and Os isotopic heterogeneity observed in rocks below the J-M Reef also suggests that A-type magmas were injected into the Stillwater U-type magma chamber at several stages during the development of the Ultramafic series.

  1. Anthropogenic Osmium in Airborne Particles from Woods Hole, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Sen, I. S.; Geboy, N.

    2012-12-01

    The global geochemical cycle of osmium has been significantly disturbed by the introduction of automobile exhaust catalysts to convert noxious gas emissions into more benign forms. Anthropogenic osmium has been reported in rainwater, snow, and in the urban airborne particles from around the world to reveal global-scale osmium pollution [1, 2]. In this study, we report on the platinum group element (PGE) concentrations and osmium isotope ratios of airborne particles (PM10) collected in Woods Hole, a small coastal town in Massachusetts to better understand inputs of anthropogenic osmium to rural environments. We further investigate the use of osmium isotopes to track sources of airborne particles and support source apportionment studies on a continental scale. The samples used in this study were collected at Woods Hole Oceanographic Institution over one year (2008-2009). From this collection twelve samples for which the backward air mass trajectories have been determined were selected for osmium isotope analyses. Our results show that the osmium and platinum concentrations are an order of magnitude lower when compared to downtown Boston [2]. The average Os, Pt and Ir concentrations are 0.006±0.012, 0.019±0.023, and 0.685±0.634 pg m-3, respectively. The 187Os/188Os of the aerosols range from 0.275 to 0.788. As continental crust is radiogenic (187Os/188Os >1) and PGE ore bodies generally have unradiogenic 187Os/188Os (~0.2), the unradiogenic 187Os/188Os signature of the aerosols indicates anthropogenic contributions. With 95% of the total osmium mobilization on land being attributed to human activities [3], it is clear that human imprint on airborne particles is not restricted to urban centers with high traffic flows, but also affects rural environments. Aerosol particles that have backward air mass trajectories from the Southwest, the densely populated and industrialized Eastern seaboard, are characterized by unradiogenic osmium, while air masses from the North

  2. Dicarba-closo-dodecarborane-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium: biological relevance and synthetic strategies.

    PubMed

    Barry, Nicolas P E; Sadler, Peter J

    2012-04-21

    This review describes how the incorporation of dicarba-closo-dodecarboranes into half-sandwich complexes of ruthenium, osmium, rhodium and iridium might lead to the development of a new class of compounds with applications in medicine. Such a combination not only has unexplored potential in traditional areas such as Boron Neutron Capture Therapy agents, but also as pharmacophores for the targeting of biologically important proteins and the development of targeted drugs. The synthetic pathways used for the syntheses of dicarba-closo-dodecarboranes-containing half-sandwich complexes of ruthenium, osmium, rhodium and iridium are also reviewed. Complexes with a wide variety of geometries and characteristics can be prepared. Examples of addition reactions on the metal centre, B-H activation, transmetalation reactions and/or direct formation of metal-metal bonds are discussed (103 references).

  3. 21 CFR 186.1750 - Sodium chlorite.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium chlorite. 186.1750 Section 186.1750 Food and... Substances Affirmed as GRAS § 186.1750 Sodium chlorite. (a) Sodium chlorite (NaCLO2, CAS Reg. No. 7758-19-2... into a solution of sodium hydroxide and hydrogen peroxide. (b) the ingredient is used at levels...

  4. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  5. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium oleate. 186.1770 Section 186.1770 Food and... Substances Affirmed as GRAS § 186.1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic acid (cis-9-octadecenoic acid). It exists as a white to yellowish...

  6. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium oleate. 186.1770 Section 186.1770 Food and... Substances Affirmed as GRAS § 186.1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic acid (cis-9-octadecenoic acid). It exists as a white to yellowish...

  7. 21 CFR 186.1771 - Sodium palmitate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium palmitate. 186.1771 Section 186.1771 Food... of Specific Substances Affirmed as GRAS § 186.1771 Sodium palmitate. (a) Sodium palmitate (C16H31O2Na, CAS Reg. No. 408-35-5) is the sodium salt of palmitic acid (hexadecanoic acid). It exists as a...

  8. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  9. 21 CFR 186.1771 - Sodium palmitate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium palmitate. 186.1771 Section 186.1771 Food... GRAS § 186.1771 Sodium palmitate. (a) Sodium palmitate (C16H31O2Na, CAS Reg. No. 408-35-5) is the sodium salt of palmitic acid (hexadecanoic acid). It exists as a white to yellow powder....

  10. 21 CFR 186.1771 - Sodium palmitate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium palmitate. 186.1771 Section 186.1771 Food... of Specific Substances Affirmed as GRAS § 186.1771 Sodium palmitate. (a) Sodium palmitate (C16H31O2Na, CAS Reg. No. 408-35-5) is the sodium salt of palmitic acid (hexadecanoic acid). It exists as a...

  11. 21 CFR 186.1771 - Sodium palmitate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium palmitate. 186.1771 Section 186.1771 Food... of Specific Substances Affirmed as GRAS § 186.1771 Sodium palmitate. (a) Sodium palmitate (C16H31O2Na, CAS Reg. No. 408-35-5) is the sodium salt of palmitic acid (hexadecanoic acid). It exists as a...

  12. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  13. 21 CFR 186.1771 - Sodium palmitate.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sodium palmitate. 186.1771 Section 186.1771 Food... of Specific Substances Affirmed as GRAS § 186.1771 Sodium palmitate. (a) Sodium palmitate (C16H31O2Na, CAS Reg. No. 408-35-5) is the sodium salt of palmitic acid (hexadecanoic acid). It exists as a...

  14. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium oleate. 186.1770 Section 186.1770 Food and... Substances Affirmed as GRAS § 186.1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic acid (cis-9-octadecenoic acid). It exists as a white to yellowish...

  15. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sodium oleate. 186.1770 Section 186.1770 Food and... Substances Affirmed as GRAS § 186.1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic acid (cis-9-octadecenoic acid). It exists as a white to yellowish...

  16. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and... Substances Affirmed as GRAS § 186.1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with...

  17. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Iron oxides. 186.1374 Section 186.1374 Food and... Substances Affirmed as GRAS § 186.1374 Iron oxides. (a) Iron oxides (oxides of iron, CAS Reg. No. 1332-37-2) are undefined mixtures of iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron...

  18. 21 CFR 186.1256 - Clay (kaolin).

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin)...

  19. 21 CFR 186.1256 - Clay (kaolin).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin)...

  20. 21 CFR 186.1256 - Clay (kaolin).

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin)...

  1. 21 CFR 186.1256 - Clay (kaolin).

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Clay (kaolin). 186.1256 Section 186.1256 Food and... Substances Affirmed as GRAS § 186.1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin)...

  2. 21 CFR 186.1316 - Formic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and...

  3. 21 CFR 186.1093 - Sulfamic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Sulfamic acid. 186.1093 Section 186.1093 Food and... Substances Affirmed as GRAS § 186.1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble...

  4. 21 CFR 186.1316 - Formic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and...

  5. 21 CFR 186.1316 - Formic acid.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and...

  6. 21 CFR 186.1316 - Formic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Formic acid. 186.1316 Section 186.1316 Food and... Substances Affirmed as GRAS § 186.1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and...

  7. 21 CFR 186.1093 - Sulfamic acid.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Sulfamic acid. 186.1093 Section 186.1093 Food and... Substances Affirmed as GRAS § 186.1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble...

  8. 21 CFR 186.1093 - Sulfamic acid.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Sulfamic acid. 186.1093 Section 186.1093 Food and... Substances Affirmed as GRAS § 186.1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble...

  9. 21 CFR 186.1093 - Sulfamic acid.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Sulfamic acid. 186.1093 Section 186.1093 Food and... Substances Affirmed as GRAS § 186.1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble...

  10. Osmium coated diffraction grating in the Space Shuttle environment - Performance

    NASA Technical Reports Server (NTRS)

    Torr, M. R.

    1985-01-01

    Samples coated with osmium were flown on the early Shuttle test flights, and on the return of these samples, the osmium coating was found to have disappeared, evidently due to the oxidation of the material in the atomic oxygen atmosphere. An instrument flown on the Spacelab 1 mission comprised an array of five spectrometers covering the extreme ultraviolet (EUV) to near-IR wavelengths. The EUV spectrometer contained an osmium-coated reflective grating located fairly deep within the instruments. Here, results of an assessment of the reflectivity and stability of the osmium surface over the course of the ten-day mission are reported. It is concluded that the osmium reflective coating remained stable relative to the spectrometer coated with MgF2 over the course of the mission. In addition, the ratio of sensitivity of these two spectrometers did not change in any major way from the time of the laboratory calibration until the time of flight two years later. Any changes are within the 50-percent calibration uncertainty.

  11. 27 CFR 19.186 - Package scales.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Package scales. 19.186... Package Scale and Pipeline Requirements § 19.186 Package scales. Proprietors must ensure that scales used.... However, if a scale is not used during a 6-month period, it is only necessary to test the scale prior...

  12. 27 CFR 19.186 - Package scales.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Package scales. 19.186... Package Scale and Pipeline Requirements § 19.186 Package scales. Proprietors must ensure that scales used.... However, if a scale is not used during a 6-month period, it is only necessary to test the scale prior...

  13. 27 CFR 19.186 - Package scales.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Package scales. 19.186... Package Scale and Pipeline Requirements § 19.186 Package scales. Proprietors must ensure that scales used.... However, if a scale is not used during a 6-month period, it is only necessary to test the scale prior...

  14. 27 CFR 19.186 - Package scales.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Package scales. 19.186... Package Scale and Pipeline Requirements § 19.186 Package scales. Proprietors must ensure that scales used.... However, if a scale is not used during a 6-month period, it is only necessary to test the scale prior...

  15. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 42 Public Health 4 2014-10-01 2014-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  16. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 42 Public Health 4 2011-10-01 2011-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  17. 42 CFR 460.186 - PACE premiums.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 42 Public Health 4 2013-10-01 2013-10-01 false PACE premiums. 460.186 Section 460.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY (PACE) PROGRAMS OF ALL-INCLUSIVE CARE FOR THE ELDERLY...

  18. 21 CFR 186.1756 - Sodium formate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium formate. 186.1756 Section 186.1756 Food and....1756 Sodium formate. (a) Sodium formate (CHNaO2, CAS Reg. No. 141-53-7) is the sodium salt of formic acid. It is produced by the reaction of carbon monoxide with sodium hydroxide. (b) The ingredient...

  19. 21 CFR 186.1797 - Sodium sulfate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium sulfate. 186.1797 Section 186.1797 Food and....1797 Sodium sulfate. (a) Sodium sulfate (Na2SO4, CAS Reg. No. 7757-82-6), also known as Glauber's salt... by the neutralization of sulfuric acid with sodium hydroxide. (b) The ingredient is used as...

  20. 21 CFR 186.1555 - Japan wax.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Japan wax. 186.1555 Section 186.1555 Food and....1555 Japan wax. (a) Japan wax (CAS Reg. No. 8001-39-6), also known as Japan tallow or sumac wax, is a... succedanea (Japan, Taiwan, and Indo-China), R. vernicifera (Japan), and R. trichocarpa (China,...

  1. 36 CFR 223.186 - Definitions.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 2 2010-07-01 2010-07-01 false Definitions. 223.186 Section 223.186 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER The Forest Resources Conservation and Shortage Relief Act of...

  2. 36 CFR 223.186 - Definitions.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 36 Parks, Forests, and Public Property 2 2013-07-01 2013-07-01 false Definitions. 223.186 Section 223.186 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE SALE AND DISPOSAL OF NATIONAL FOREST SYSTEM TIMBER, SPECIAL FOREST PRODUCTS, AND FOREST BOTANICAL PRODUCTS...

  3. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  4. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  5. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  6. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  7. 21 CFR 186.1673 - Pulp.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... food packaging containers. (c) The ingredient is used in paper and paperboard made by conventional... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Pulp. 186.1673 Section 186.1673 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT...

  8. 21 CFR 186.1275 - Dextrans.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Dextrans. 186.1275 Section 186.1275 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of...

  9. 15 CFR 922.186 - Penalties; appeals.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 922.186 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Hawaiian Islands Humpback Whale National Marine Sanctuary § 922.186 Penalties; appeals. (a) Pursuant to section 307 of the NMSA, each violation of either...

  10. 15 CFR 922.186 - Penalties; appeals.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 922.186 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Hawaiian Islands Humpback Whale National Marine Sanctuary § 922.186 Penalties; appeals. (a) Pursuant to section 307 of the NMSA, each violation of either...

  11. 15 CFR 922.186 - Penalties; appeals.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 922.186 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Hawaiian Islands Humpback Whale National Marine Sanctuary § 922.186 Penalties; appeals. (a) Pursuant to section 307 of the NMSA, each violation of either...

  12. 15 CFR 922.186 - Penalties; appeals.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 922.186 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Hawaiian Islands Humpback Whale National Marine Sanctuary § 922.186 Penalties; appeals. (a) Pursuant to section 307 of the NMSA, each violation of either...

  13. 15 CFR 922.186 - Penalties; appeals.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 922.186 Commerce and Foreign Trade Regulations Relating to Commerce and Foreign Trade (Continued... MANAGEMENT NATIONAL MARINE SANCTUARY PROGRAM REGULATIONS Hawaiian Islands Humpback Whale National Marine Sanctuary § 922.186 Penalties; appeals. (a) Pursuant to section 307 of the NMSA, each violation of either...

  14. Accretion rate of extraterrestrial particles determined from osmium isotope systematics of pacific pelagic clay and manganese nodules

    SciTech Connect

    Esser, B.K.; Turekian, K.K. )

    1988-06-01

    Pelagic clay and Mn nodules from DOMES sites in the North Pacific and a varved glacial lake deposit from Connecticut were analyzed for Os concentration and isotopic composition by isotope-dilution secondary ion mass spectrometry after treatment by NiS fusion of oxalic acid leaching. Bulk pelagic clay from DOMES site C has {sup 187}Os/{sup 186}Os = 6.5 and Os = 0.14 ng/g. Oxalic acid leaches of this same sediment and of Mn nodules for DOMES sites A and C have more radiogenic {sup 187}Os/{sup 186}Os ratios which average 8.3. Bulk glacial Lake Hitchcock sediment has {sup 187}Os/{sup 186}Os = 12.5 and Os = 0.06 ng/g. The total Os flux to North Pacific pelagic clay is 7 to 10 ng Os/cm{sup 2}/10{sup 6} y. Lake Hitchcock sediment provides an integrated value for the local crustal {sup 187}Os/{sup 186}Os ratio. The oxalic acid leaches are assumed to attack hydrogenous phases selectively. A simple model in which the only sources of Os to the ocean are continental crust with the isotopic composition of Lake Hitchcock and extraterrestrial particles with {sup 187}Os/{sup 186}Os = 1.1 results in a cosmic flux of osmium to the sediment of 4.9 ng Os/cm{sup 2}/10{sub 6} y of which 20% is hydrogenous. A model in which the sources of Os to the ocean are continental crust with an {sup 187}Os/{sup 186}Os ratio of 30, oceanic mantle or crust with {sup 187}Os/{sup 186}Os = 1.04 and extraterrestrial particles with {sup 187}Os/{sup 186}Os = 1.1 results in a cosmic flux of Os to the sediment of 5.7 ng Os/cm{sup 2}/10{sup 6} y of which none is hydrogenous. These extraterrestrial Os fluxes correspond to maximum C-1 chondrite accretion rates of between 4.9 {times} 10{sub 4} and 5.6 {times}10{sub 4} tonnes/y.

  15. Osmium-labeled polynucleotides: reaction of osmium tetraoxide, with poly-1,N6-ethenoadenylic acid.

    PubMed

    Marzilli, L G; Hanson, B E; Kapili, L; Rose, S D; Beer, M

    1978-06-01

    Osmium tetraoxide, in the presence of ligands such as pyridine and bipyridine, adds across the etheno bridge of 1,N6-etheno-9-methyladenine and poly-1,N6-ethenoadenylic acid. The Os:P ratio in the labeled polynucleotide was approximately equal to 1 when bipyridine was used as the stabilizing ligand. A similar study with polycytidylic acid, which had been partially modified with chloroacetaldehyde so that some bases were converted to 3,N4-ethenocytosine, gave an OS:P ratio of approximately equal to 1.3. Calf-thymus DNA, in which the adenine and cytosine bases were modified by chloroacetaldehyde, gave an Os:P ratio of approximately equal to 1 after 24 h. These results suggest that 3,N4-ethenocytosine will add two Os labels.

  16. Mechanism Elucidation of the cis–trans Isomerization of an Azole Ruthenium–Nitrosyl Complex and Its Osmium Counterpart

    PubMed Central

    2013-01-01

    Synthesis and X-ray diffraction structures of cis and trans isomers of ruthenium and osmium metal complexes of general formulas (nBu4N)[cis-MCl4(NO)(Hind)], where M = Ru (1) and Os (3), and (nBu4N)[trans-MCl4(NO)(Hind)], where M = Ru (2) and Os (4) and Hind = 1H-indazole are reported. Interconversion between cis and trans isomers at high temperatures (80–130 °C) has been observed and studied by NMR spectroscopy. Kinetic data indicate that isomerizations correspond to reversible first order reactions. The rates of isomerization reactions even at 110 °C are very low with rate constants of 10–5 s–1 and 10–6 s–1 for ruthenium and osmium complexes, respectively, and the estimated rate constants of isomerization at room temperature are of ca. 10–10 s–1. The activation parameters, which have been obtained from fitting the reaction rates at different temperatures to the Eyring equation for ruthenium [ΔHcis-trans‡= 122.8 ± 1.3; ΔHtrans-cis‡= 138.8 ± 1.0 kJ/mol; ΔScis-trans‡= −18.7 ± 3.6; ΔStrans-cis‡= 31.8 ± 2.7 J/(mol·K)] and osmium [ΔHcis-trans‡= 200.7 ± 0.7; ΔHtrans-cis‡= 168.2 ± 0.6 kJ/mol; ΔScis-trans‡= 142.7 ± 8.9; ΔStrans-cis‡= 85.9 ± 3.9 J/(mol·K)] reflect the inertness of these systems. The entropy of activation for the osmium complexes is highly positive and suggests the dissociative mechanism of isomerization. In the case of ruthenium, the activation entropy for the cis to trans isomerization is negative [−18.6 J/(mol·K)], while being positive [31.0 J/(mol·K)] for the trans to cis conversion. The thermodynamic parameters for cis to trans isomerization of [RuCl4(NO)(Hind)]−, viz. ΔH° = 13.5 ± 1.5 kJ/mol and ΔS° = −5.2 ± 3.4 J/(mol·K) indicate the low difference between the energies of cis and trans isomers. The theoretical calculation has been carried out on isomerization of ruthenium complexes with DFT methods. The dissociative, associative, and intramolecular twist isomerization mechanisms have

  17. Mechanism elucidation of the cis-trans isomerization of an azole ruthenium-nitrosyl complex and its osmium counterpart.

    PubMed

    Gavriluta, Anatolie; Büchel, Gabriel E; Freitag, Leon; Novitchi, Ghenadie; Tommasino, Jean Bernard; Jeanneau, Erwann; Kuhn, Paul-Steffen; González, Leticia; Arion, Vladimir B; Luneau, Dominique

    2013-06-03

    Synthesis and X-ray diffraction structures of cis and trans isomers of ruthenium and osmium metal complexes of general formulas (nBu4N)[cis-MCl4(NO)(Hind)], where M = Ru (1) and Os (3), and (nBu4N)[trans-MCl4(NO)(Hind)], where M = Ru (2) and Os (4) and Hind = 1H-indazole are reported. Interconversion between cis and trans isomers at high temperatures (80-130 °C) has been observed and studied by NMR spectroscopy. Kinetic data indicate that isomerizations correspond to reversible first order reactions. The rates of isomerization reactions even at 110 °C are very low with rate constants of 10(-5) s(-1) and 10(-6) s(-1) for ruthenium and osmium complexes, respectively, and the estimated rate constants of isomerization at room temperature are of ca. 10(-10) s(-1). The activation parameters, which have been obtained from fitting the reaction rates at different temperatures to the Eyring equation for ruthenium [ΔH(cis-trans)‡ = 122.8 ± 1.3; ΔH(trans-cis)‡ = 138.8 ± 1.0 kJ/mol; ΔS(cis-trans)‡ = -18.7 ± 3.6; ΔS(trans-cis)‡ = 31.8 ± 2.7 J/(mol·K)] and osmium [ΔH(cis-trans)‡ = 200.7 ± 0.7; ΔH(trans-cis)‡ = 168.2 ± 0.6 kJ/mol; ΔS(cis-trans)‡ = 142.7 ± 8.9; ΔS(trans-cis)‡ = 85.9 ± 3.9 J/(mol·K)] reflect the inertness of these systems. The entropy of activation for the osmium complexes is highly positive and suggests the dissociative mechanism of isomerization. In the case of ruthenium, the activation entropy for the cis to trans isomerization is negative [-18.6 J/(mol·K)], while being positive [31.0 J/(mol·K)] for the trans to cis conversion. The thermodynamic parameters for cis to trans isomerization of [RuCl4(NO)(Hind)]-, viz. ΔH° = 13.5 ± 1.5 kJ/mol and ΔS° = -5.2 ± 3.4 J/(mol·K) indicate the low difference between the energies of cis and trans isomers. The theoretical calculation has been carried out on isomerization of ruthenium complexes with DFT methods. The dissociative, associative, and intramolecular twist isomerization

  18. Discovery of tantalum, rhenium, osmium, and iridium isotopes

    SciTech Connect

    Robinson, R.; Thoennessen, M.

    2012-09-15

    Currently, thirty-eight tantalum, thirty-eight rhenium, thirty-nine osmium, and thirty-eight iridium isotopes have been observed and the discovery of these isotopes is described here. For each isotope a brief synopsis of the first refereed publication, including the production and identification method, is presented.

  19. Improved microbial electrocatalysis with osmium polymer modified electrodes.

    PubMed

    Patil, Sunil A; Hasan, Kamrul; Leech, Dónal; Hägerhäll, Cecilia; Gorton, Lo

    2012-10-21

    Using the well-known exoelectrogen Shewanella oneidensis MR-1, an osmium redox polymer modified anode exhibited ca. 4-fold increase in current generation. Additionally, a significant decrease in the start-up time for electrocatalysis was observed. The findings suggest that the inherent extracellular electron transfer capabilities of electrogens coupled with such polymers could enhance electrocatalysis.

  20. Osmium isotopic tracing of atmospheric emissions from an aluminum smelter

    NASA Astrophysics Data System (ADS)

    Gogot, Julien; Poirier, André; Boullemant, Amiel

    2015-09-01

    We present for the first time the use of osmium isotopic composition as a tracer of atmospheric emissions from an aluminum smelter, where alumina (extracted from bauxite) is reduced through electrolysis into metallic aluminum using carbonaceous anodes. These anodes are consumed in the process; they are made of petroleum coke and pitch and have high Re/Os elementary ratio. Due to the relatively large geological age of their source material, their osmium shows a high content of radiogenic 187Os produced from in situ187Re radioactive decay. The radiogenic isotopic composition (187Os/188Os ∼ 2.5) of atmospheric particulate emissions from this smelter is different from that of other typical anthropogenic osmium sources (that come from ultramafic geological contexts with unradiogenic Os isotopes, e.g., 187Os/188Os < 0.2) and also different from average eroding continental crust 187Os/188Os ratios (ca. 1.2). This study demonstrates the capacity of osmium measurements to monitor particulate matter emissions from the Al-producing industry.

  1. 40 CFR 61.186 - Reporting requirements.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... alternative arsenic trioxide production processes. Conclusions and recommendations of the studies shall...

  2. 40 CFR 61.186 - Reporting requirements.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... alternative arsenic trioxide production processes. Conclusions and recommendations of the studies shall...

  3. 40 CFR 61.186 - Reporting requirements.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... alternative arsenic trioxide production processes. Conclusions and recommendations of the studies shall...

  4. 40 CFR 61.186 - Reporting requirements.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... alternative arsenic trioxide production processes. Conclusions and recommendations of the studies shall...

  5. 40 CFR 61.186 - Reporting requirements.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...) NATIONAL EMISSION STANDARDS FOR HAZARDOUS AIR POLLUTANTS National Emission Standard for Inorganic Arsenic Emissions From Arsenic Trioxide and Metallic Arsenic Production Facilities § 61.186 Reporting requirements... alternative arsenic trioxide production processes. Conclusions and recommendations of the studies shall...

  6. Osmium-Isotope and Platinum-Group-Element Systematics of Impact-Melt Rocks, Chesapeake Bay Impact Structure, Virginia, USA

    NASA Technical Reports Server (NTRS)

    Lee, Seung Ryeol; Wright Horton, J., Jr.; Walker, Richard J.

    2005-01-01

    Osmium (Os) isotopes and platinum-group elements (PGEs) are useful for geochemically identifying a meteoritic component within impact structures, because meteorites are typically characterized by low (187)Os/(188)Os ratios and high PGE concentrations. In contrast, most types of crustal target rocks have high radiogenic Os and very low PGE concentrations. We have examined Os isotope and PGE systematics of impact-melt rocks and pre-impact target rocks from a 2004 test hole in the late Eocene Chesapeake Bay impact structure and from nearby coreholes. Our goal is to determine the proportion of the projectile component in the melt rock Additional information is included in the original extended abstract.

  7. 21 CFR 186.1770 - Sodium oleate.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sodium oleate. 186.1770 Section 186.1770 Food and....1770 Sodium oleate. (a) Sodium oleate (C18H33O2Na, CAS Reg. No. 143-19-1) is the sodium salt of oleic.... Commercially, sodium oleate is made by mixing and heating flaked sodium hydroxide and oleic acid. (b)...

  8. 21 CFR 186.1557 - Tall oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Tall oil. 186.1557 Section 186.1557 Food and Drugs....1557 Tall oil. (a) Tall oil (CAS Reg. No. 8002-26-4) is essentially the sap of the pine tree. It is obtained commercially from the waste liquors of pinewood pulp mills and consists mainly of tall oil...

  9. 21 CFR 186.1256 - Clay (kaolin).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Clay (kaolin). 186.1256 Section 186.1256 Food and....1256 Clay (kaolin). (a) Clay (kaolin) Al2O3.2SiO2.nH2O, Cas Reg. No. 1332-58-7) consists of hydrated aluminum silicate. The commercial products of clay (kaolin) contain varying quantities of alkalies...

  10. 21 CFR 186.1093 - Sulfamic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Sulfamic acid. 186.1093 Section 186.1093 Food and....1093 Sulfamic acid. (a) Sulfamic acid (H3NO3S, CAS Reg. No. 5329-14-6) is a white crystalline solid manufactured from urea, sulfur trioxide, and sulfuric acid. It is soluble and highly ionized in water. (b)...

  11. 21 CFR 186.1316 - Formic acid.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Formic acid. 186.1316 Section 186.1316 Food and....1316 Formic acid. (a) Formic acid (CH2O2, CAS Reg. No. 64-18-6) is also referred to as methanoic acid or hydrogen carboxylic acid. It occurs naturally in some insects and is contained in the free...

  12. MiR-186 inhibited aerobic glycolysis in gastric cancer via HIF-1α regulation

    PubMed Central

    Liu, L; Wang, Y; Bai, R; Yang, K; Tian, Z

    2016-01-01

    Deregulation of microRNAs in human malignancies has been well documented, among which microRNA-186 (miR-186) has an antiproliferative role in some carcinomas. Here we demonstrate that low expression of miR-186 facilitates aerobic glycolysis in gastric cancer. MiR-186 suppresses cell proliferation induced by hypoxia inducible factor 1 alpha (HIF-1α) in gastric cancer cell lines MKN45 and SGC7901. Cellular glycolysis, including cellular glucose uptake, lactate, ATP/ADP and NAD+/NADH ratios, are also inhibited by miR-186. The negative regulation of miR-186 on HIF-1α effects its downstream targets, including programmed death ligand 1 and two glycolytic key enzymes, hexokinase 2 and platelet-type phosphofructokinase. The antioncogenic effects of miR-186 are proved by in vivo xenograft tumor experiment. The results demonstrate that the miR-186/HIF-1α axis has an antioncogenic role in gastric cancer. PMID:27159677

  13. A breast cancer stem cell-selective, mammospheres-potent osmium(VI) nitrido complex.

    PubMed

    Suntharalingam, Kogularamanan; Lin, Wei; Johnstone, Timothy C; Bruno, Peter M; Zheng, Yao-Rong; Hemann, Michael T; Lippard, Stephen J

    2014-10-15

    The effect of a newly developed osmium(VI) nitrido complex, 1, on breast cancer stem cells (CSCs) is reported. The complex displays selective toxicity for HMLER breast cancer cells enriched with CD44-positive, CSC-like cells over the same cells having reduced CSC character. Remarkably, 1 also reduces the proportion of CSCs within a heterogeneous breast cancer cell population and irreversibly inhibits the formation of free-floating mammospheres to an extent similar to that of salinomycin, a natural product that targets CSCs. Detailed mechanistic studies reveal that in breast cancer cells 1 induces DNA damage and endoplasmic reticulum stress, the latter being responsible for the CSC selectivity. The anti-CSC properties of 1 provide a strong impetus for the development of new metal-based compounds to target CSCs and to treat chemotherapy-resistant and relapsed tumors.

  14. miR-186 affects the proliferation, invasion and migration of human gastric cancer by inhibition of Twist1

    PubMed Central

    Cao, Chunhong; Sun, Deguang; Zhang, Liang; Song, Lei

    2016-01-01

    Recent evidence shows that miRNAs are dysregulated in a variety of cancers including gastric cancer (GC), and emerging as key oncogenes or tumor suppressors. In this study, qRT-PCR was used to analyze the expression of miR-186 in GC tissues and adjacent non-cancerous tissues, and then more in-vitro experiments were used to investigate the role of miR-186 in GC cells. Here, we identified miR-186 was generally down-regulated in GC tissues; however, Twist1 was generally up-regulated in GC tissues. Moreover, miR-186 and Twist1 were associated with larger tumor size and advanced clinical stage of GC. In-vitro experiments demonstrated that ectopic overexpression of miR-186 inhibited GC cell proliferation, invasion and migration; however, inhibited expression of miR-186 enhanced cell proliferation, invasion and migration. Furthermore, the luciferase reporter assay demonstrated Twist1 as a direct target of miR-186. Finally, over-expression of Twist1 abrogated inhibitory impact of miR-186 on cell proliferation, invasion and migration. In conclusion, miR-186 affects the proliferation, invasion and migration of human gastric cancer by inhibition of Twist1, and could be a tumor suppressor in GC development. Thus, miR-186 may be served as a candidate prognostic biomarker and target for new therapies in human gastric cancer. PMID:27835599

  15. Osmium-187 enrichment in some plumes: Evidence for core-mantle interaction?

    USGS Publications Warehouse

    Walker, R.J.; Morgan, J.W.; Horan, M.F.

    1995-01-01

    Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the chondritic upper mantle, potentially leading to an outer core with an osmium-187/osmium-188 ratio at least 8 percent greater than that of chondrites. Because of the much greater abundance of osmium in the outer core relative to the mantle, even a small addition of metal to a plume ascending from the D??? layer would transfer the enriched isotopic signature to the mixture. Sources of certain plume-derived systems seem to have osmium-187/osmium-188 ratios 5 to 20 percent greater than that for chondrites, consistent with the ascent of a plume from the core-mantle boundary.

  16. Osmium-187 Enrichment in Some Plumes: Evidence for Core-Mantle Interaction?

    NASA Astrophysics Data System (ADS)

    Walker, Richard J.; Morgan, John W.; Horan, Mary F.

    1995-08-01

    Calculations with data for asteroidal cores indicate that Earth's outer core may have a rhenium/osmium ratio at least 20 percent greater than that of the chondritic upper mantle, potentially leading to an outer core with an osmium-187/osmium-188 ratio at least 8 percent greater than that of chondrites. Because of the much greater abundance of osmium in the outer core relative to the mantle, even a small addition of metal to a plume ascending from the D'' layer would transfer the enriched isotopic signature to the mixture. Sources of certain plume-derived systems seem to have osmium-187/osmium-188 ratios 5 to 20 percent greater than that for chondrites, consistent with the ascent of a plume from the core-mantle boundary.

  17. Osmium Isotopic Evolution in Cumulate Piles at the Core-Mantle Boundary

    NASA Astrophysics Data System (ADS)

    Humayun, M.

    2009-12-01

    Osmium isotopic and Fe/Mn elemental tracers imply that chemical signals originating from the core are observed in some mantle plumes, particularly Hawaii. The discovery of radiogenic Os-186 in Hawaii requires a reservoir with time-integrated high Pt/Os ratios and Pt/Re ratios, proposed to be the Earth’s outer core. The radiogenic in-growth of Os-186 is directly proportional to time and Pt/Os ratio, so that any process acting more recently than the Hadean must create even larger Pt/Os fractionations. In the iron meteorite-analog model proposed to-date, the high Pt/Os ratio of the outer core is acquired by fractional crystallization of the inner core. To create sufficient Pt/Os fractionation, this model requires that: 1) substantial inner core growth had occurred prior to 3.5 Ga, and 2) the partition coefficients have extremely high values requiring the maximum amount of sulfur, or other light elements, possible in the core. The need for such extreme values is a vulnerability of the iron meteorite-analog model. The time constraint is in conflict with inner core growth models inferred from core heat flow requiring alternative heat sources for the core. Further, high Fe/Mn ratios are observed in every major Hawaiian volcano while these volcanoes exhibit a wide range of Os isotopic compositions from unradiogenic to radiogenic. Seismically observed features termed core rigidity zones at the core-mantle boundary have been interpreted to be flotation cumulate piles of FeO-rich material. Such features are not necessarily permanent, but may lose mass to the mantle by incorporation into plumes originating at the CMB. Here, I propose an alternative model for obtaining radiogenic Os-186, correlated with Os-187, from the core by examining the likely chemical evolution of a flotation cumulate pile of FeO-rich material. Fractional crystallization of trapped intercumulus metallic liquid in the cumulate pile produces solid metal with low Pt/Os ratios, and a residual liquid with

  18. 76 FR 49755 - Revision to the Standard Forms 76, 76A, 186, and 186A

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-11

    ... Defense for Personnel and Readiness, Federal Voting Assistance Program, Department of Defense. ACTION... Voting Assistance Program, revised the SF 76, Federal Post Card Application (FPCA), SF 76A, Federal Post Card Application (Electronic), SF 186, Federal Write-in Absentee Ballot (FWAB), and SF 186A,...

  19. Osmium isotope constraints on Earth's late accretionary history

    USGS Publications Warehouse

    Morgan, J.W.

    1985-01-01

    Osmium isotope measurements reported by Alle??gre and Luck 1,2 indicate that terrestrial osmiridiums evolved in a mantle source region in which the osmium/rhenium ratio falls strictly within the range found in chondrites. This suggests that the highly siderophile elements in the Earth's mantle were introduced by a late influx of chondritic material and are not a result of endogenous processes. I have now examined the available data in more detail and conclude that the inferred Os/Re ratio of the Earth's mantle matches the E group and C3 chondrites, but that C1 and probably C2 chondrites were not major components of the material accreted in the late stages of mantle formation. ?? 1985 Nature Publishing Group.

  20. Elongated Dihydrogen versus Compressed Dihydride in Osmium Complexes.

    PubMed

    Eguillor, Beatriz; Esteruelas, Miguel A; Lezáun, Virginia; Oliván, Montserrat; Oñate, Enrique

    2017-01-31

    Small modifications on the co-ligands of complexes containing two coordinated hydrogen atoms can determine the elongated dihydrogen versus compressed dihydride nature of these species and therefore their chemical behavior. 2,6-diphenylpyridine favors the formation of the osmium(IV) cation [OsH2 (C6 H4 pyPh)(PiPr3 )2 ](+) , whereas 2-phenoxy-6-phenylpyridine, which contains an oxygen atom between the heterocycle and one of the phenyl groups, stabilizes the osmium(II) elongated dihydrogen species [Os(C6 H4 pyOPh)(η(2) -H2 )(PiPr3 )2 ](+) . In contrast to the latter, the former shows a marked tendency to undergo reductive elimination of the heterocycle.

  1. Anticancer Organometallic Osmium(II)-p-cymene Complexes.

    PubMed

    Păunescu, Emilia; Nowak-Sliwinska, Patrycja; Clavel, Catherine M; Scopelliti, Rosario; Griffioen, Arjan W; Dyson, Paul J

    2015-09-01

    Osmium compounds are attracting increasing attention as potential anticancer drugs. In this context, a series of bifunctional organometallic osmium(II)-p-cymene complexes functionalized with alkyl or perfluoroalkyl groups were prepared and screened for their antiproliferative activity. Three compounds from the series display selectivity toward cancer cells, with moderate cytotoxicity observed against human ovarian carcinoma (A2780) cells, whereas no cytotoxicity was observed on non-cancerous human embryonic kidney (HEK-293) cells and human endothelial (ECRF24) cells. Two of these three cancer-cell-selective compounds induce cell death largely via apoptosis and were also found to disrupt vascularization in the chicken embryo chorioallantoic membrane (CAM) model. Based on these promising properties, these compounds have potential clinical applications.

  2. Isotopic determinations of rhenium and osmium in meteorites by using fusion, distillation and ion-exchange separations

    USGS Publications Warehouse

    Morgan, J.W.; Walker, R.J.

    1989-01-01

    A stable isotope-dilution method using resonance ionization mass spectrometry is suitable for the determination of rhenium and osmium abundances and osmium isotopic composition in carbonaceous chondrites and iron meteorites. The chemical procedure involves sodium peroxide fusion, followed by distillation of osmium from sulfuric acid/hydrogen peroxide and subsequent anion-exchange separation of rhenium from the same solution. ?? 1989.

  3. 21 CFR 186.1374 - Iron oxides.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... iron (II) oxide (CAS Reg. No. 1345-25-1, black cubic crystals) and iron (III) oxide (CAS Reg. No. 1309-37-1, red-brown to black trigonal crystals). (b) In accordance with § 186.1(b)(1), the ingredient...

  4. 38 CFR 18.6 - Compliance information.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 38 Pensions, Bonuses, and Veterans' Relief 2 2010-07-01 2010-07-01 false Compliance information... THE CIVIL RIGHTS ACT OF 1964 General § 18.6 Compliance information. (a) Cooperation and assistance... compliance reports at such times, and in such form and containing such information, as the responsible...

  5. Methods for the separation of rhenium, osmium and molybdenum applicable to isotope geochemistry

    USGS Publications Warehouse

    Morgan, J.W.; Golightly, D.W.; Dorrzapf, A.F.

    1991-01-01

    Effective methods are described for the chemical separation of rhenium, osmium and molybdenum. The methods are based on distillation and anion-exchange chromatography, and have been the basis for rhenium-osmium isotope studies of ore deposits and meteorites. Successful anion-exchange separation of osmium requires both recognition and careful control of the osmium species in solution; thus, distillation of osmium tetroxide from a mixture of sulfuric acid and hydrogen peroxide is preferred to anion-exchange. Distribution coefficients measured for perrhenate in sulfuric acid media are sufficiently high (Kd > 500) for rhenium to be directly loaded onto an ion-exchange column from a distillation residue and subsequently eluted with nitric acid. Polymerization of molybdenum species during elution is prevented by use of a solution that is 1M in hydrochloric acid and 1M in sodium chloride. ?? 1991.

  6. Structure-activity relationships for organometallic osmium arene phenylazopyridine complexes with potent anticancer activity.

    PubMed

    Fu, Ying; Habtemariam, Abraha; Basri, Aida M B H; Braddick, Darren; Clarkson, Guy J; Sadler, Peter J

    2011-10-28

    We report the synthesis and characterisation of 32 half sandwich phenylazopyridine Os(II) arene complexes [Os(η(6)-arene)(phenylazopyridine)X](+) in which X is chloride or iodide, the arene is p-cymene or biphenyl and the pyridine and phenyl rings contain a variety of substituents (F, Cl, Br, I, CF(3), OH or NO(2)). Ten X-ray crystal structures have been determined. Cytotoxicity towards A2780 human ovarian cancer cells ranges from high potency at nanomolar concentrations to inactivity. In general the introduction of an electron-withdrawing group (e.g. F, Cl, Br or I) at specific positions on the pyridine ring significantly increases cytotoxic activity and aqueous solubility. Changing the arene from p-cymene to biphenyl and the monodentate ligand X from chloride to iodide also increases the activity significantly. Activation by hydrolysis and DNA binding appears not to be the major mechanism of action since both the highly active complex [Os(η(6)-bip)(2-F-azpy)I]PF(6) (9) and the moderately active complex [Os(η(6)-bip)(3-Cl-azpy)I]PF(6) (23) are very stable and inert towards aquation. Studies of octanol-water partition coefficients (log P) and subcellular distributions of osmium in A2780 human ovarian cancer cells suggested that cell uptake and targeting to cellular organelles play important roles in determining activity. Although complex 9 induced the production of reactive oxygen species (ROS) in A2780 cells, the ROS level did not appear to play a role in the mechanism of anticancer activity. This class of organometallic osmium complexes has new and unusual features worthy of further exploration for the design of novel anticancer drugs.

  7. Potent organo-osmium compound shifts metabolism in epithelial ovarian cancer cells.

    PubMed

    Hearn, Jessica M; Romero-Canelón, Isolda; Munro, Alison F; Fu, Ying; Pizarro, Ana M; Garnett, Mathew J; McDermott, Ultan; Carragher, Neil O; Sadler, Peter J

    2015-07-21

    The organometallic "half-sandwich" compound [Os(η(6)-p-cymene)(4-(2-pyridylazo)-N,N-dimethylaniline)I]PF6 is 49× more potent than the clinical drug cisplatin in the 809 cancer cell lines that we screened and is a candidate drug for cancer therapy. We investigate the mechanism of action of compound 1 in A2780 epithelial ovarian cancer cells. Whole-transcriptome sequencing identified three missense mutations in the mitochondrial genome of this cell line, coding for ND5, a subunit of complex I (NADH dehydrogenase) in the electron transport chain. ND5 is a proton pump, helping to maintain the coupling gradient in mitochondria. The identified mutations correspond to known protein variants (p.I257V, p.N447S, and p.L517P), not reported previously in epithelial ovarian cancer. Time-series RNA sequencing suggested that osmium-exposed A2780 cells undergo a metabolic shunt from glycolysis to oxidative phosphorylation, where defective machinery, associated with mutations in complex I, could enhance activity. Downstream events, measured by time-series reverse-phase protein microarrays, high-content imaging, and flow cytometry, showed a dramatic increase in mitochondrially produced reactive oxygen species (ROS) and subsequent DNA damage with up-regulation of ATM, p53, and p21 proteins. In contrast to platinum drugs, exposure to this organo-osmium compound does not cause significant apoptosis within a 72-h period, highlighting a different mechanism of action. Superoxide production in ovarian, lung, colon, breast, and prostate cancer cells exposed to three other structurally related organo-Os(II) compounds correlated with their antiproliferative activity. DNA damage caused indirectly, through selective ROS generation, may provide a more targeted approach to cancer therapy and a concept for next-generation metal-based anticancer drugs that combat platinum resistance.

  8. POX 186: A Dwarf Galaxy Under Construction?

    NASA Astrophysics Data System (ADS)

    Corbin, M. R.; Vacca, W. D.

    2000-12-01

    We have obtained deep images of the ultracompact ( ~ 3'') blue compact dwarf galaxy POX 186 in the F336W, F555W, and F814W filters of the Planetary Camera of the Hubble Space Telescope. We have additionally obtained a low-resolution near ultraviolet spectrum of the object with STIS and combine this with a ground-based spectrum covering the visible continuum and emission lines. Our images confirm this object to be highly compact, with a maximum projected size of only ~ 240 pc, making it one of the smallest galaxies known. We also confirm that the outer regions of the galaxy consist of an evolved stellar population, ruling out earlier speculations that POX 186 is a protogalaxy. However, the PC images reveal the galaxy to have a highly irregular morphology, with a pronounced tidal arm on its western side. This morphology is strongly suggestive of a recent collision between two smaller components which has in turn triggered the central starburst. The F336W image also shows that the material in this tidal stream is actively star forming. Given the very small ( ~ 100 pc) sizes of the colliding components, POX 186 may be a dwarf galaxy in the early stages of formation, which would be consistent with current ``downsizing'' models of galaxy formation in which the least massive objects are the last to form. This work is supported by NASA and the Space Telescope Science Institute.

  9. Incompressibility of osmium metal at ultrahigh pressures and temperatures

    SciTech Connect

    Armentrout, Matt M.; Kavner, Abby

    2010-07-23

    Osmium is one of the most incompressible elemental metals, and is used as a matrix material for synthesis of ultrahard materials. To examine the behavior of osmium metal under extreme conditions of high pressure and temperature, we measured the thermal equation of state of osmium metal at pressures up to 50 GPa and temperatures up to 3000 K. X-ray diffraction measurements were conducted in the laser heated diamond anvil cell at GeoSoilEnviroCARS and the High Pressure at the Advanced Photon Source and beamline 12.2.2 at the advanced light source. Ambient temperature data give a zero pressure bulk modulus of 421 (3) GPa with a first pressure derivative fixed at 4. Fitting to a high temperature Birch-Murnaghan equation of state gives a room pressure thermal expansion of 1.51(0.06) x 10{sup -5} K{sup -1} with a first temperature derivative of 4.9(0.7) x 10{sup -9} K{sup -2} and the first temperature derivative of bulk modulus of be dK{sub 0}/dT = -0.055 (0.004). Fitting to a Mie-Grueneisen-Debye equation of state gives a Grueneisen parameter of 2.32 (0.08) with a q of 7.2 (1.4). A comparison of the high pressure, temperature behavior among Re, Pt, Os, shows that Os has the highest bulk modulus and lowest thermal expansion of the three, suggesting that Os-based ultrahard materials may be especially mechanically stable under extreme conditions.

  10. Osmium Metal Studied under High Pressure and Nonhydrostatic Stress

    SciTech Connect

    Weinberger,M.; Tolbert, S.; Kavner, A.

    2008-01-01

    Interest in osmium as an ultra-incompressible material and as an analog for the behavior of iron at high pressure has inspired recent studies of its mechanical properties. We have measured elastic and plastic deformation of Os metal at high pressures using in situ high pressure x-ray diffraction in the radial geometry. We show that Os has the highest yield strength observed for any pure metal, supporting up to 10 GPa at a pressure of 26 GPa. Furthermore, our data indicate changes in the nonhydrostatic apparent c/a ratio and clear lattice preferred orientation effects at pressures above 15 GPa.

  11. Organometallic osmium arene complexes with potent cancer cell cytotoxicity.

    PubMed

    Fu, Ying; Habtemariam, Abraha; Pizarro, Ana M; van Rijt, Sabine H; Healey, David J; Cooper, Patricia A; Shnyder, Steven D; Clarkson, Guy J; Sadler, Peter J

    2010-11-25

    Iodido osmium(II) complexes [Os(η(6)-arene)(XY)I](+) (XY = p-hydroxy or p-dimethylaminophenylazopyridine, arene = p-cymene or biphenyl) are potently cytotoxic at nanomolar concentrations toward a panel of human cancer cell lines; e.g., IC(50) = 140 nM for [Os(η(6)-bip)(azpy-NMe(2))I](+) toward A2780 ovarian cancer cells. They exhibit low toxicity and negligible deleterious effects in a colon cancer xenograft model, giving rise to the possibility of a broad therapeutic window. The most active complexes are stable and inert toward aquation. Their cytotoxic activity appears to involve redox mechanisms.

  12. New modes for the osmium-catalyzed oxidative cyclization.

    PubMed

    Donohoe, Timothy J; Lindsay-Scott, Peter J; Parker, Jeremy S; Callens, Cedric K A

    2010-03-05

    The osmium-catalyzed oxidative cyclization of amino alcohol initiators formally derived from 1,4-dienes is an effective method for the construction of pyrrolidines, utilizing a novel reoxidant (4-nitropyridine N-oxide = NPNO). The cyclization of enantiopure syn- and anti-amino alcohols gives rise to enantiopure cis- and trans-2,5-disubstituted pyrrolidines, respectively. Moreover, the cyclization of bis-homoallylic amines bearing an exocyclic chelating group is shown to be a complementary method for trans-pyrrolidine formation.

  13. Osmium isotope constraints on ore metal recycling in subduction zones

    PubMed

    McInnes; McBride; Evans; Lambert; Andrew

    1999-10-15

    Veined peridotite xenoliths from the mantle beneath the giant Ladolam gold deposit on Lihir Island, Papua New Guinea, are 2 to 800 times more enriched in copper, gold, platinum, and palladium than surrounding depleted arc mantle. Gold ores have osmium isotope compositions similar to those of the underlying subduction-modified mantle peridotite source region, indicating that the primary origin of the metals was the mantle. Because the mantle is relatively depleted in gold, copper, and palladium, tectonic processes that enhance the advective transport and concentration of these fluid soluble metals may be a prerequisite for generating porphyry-epithermal copper-gold deposits.

  14. A quantitative link between recycling and osmium isotopes.

    PubMed

    Sobolev, Alexander V; Hofmann, Albrecht W; Brügmann, Gerhard; Batanova, Valentina G; Kuzmin, Dmitry V

    2008-07-25

    Recycled subducted ocean crust has been traced by elevated 187Os/188Os in some studies and by high nickel and low manganese contents in others. Here, we show that these tracers are linked for Quaternary lavas of Iceland, strengthening the recycling model. An estimate of the osmium isotopic composition of both the recycled crust and the mantle peridotite implies that Icelandic Quaternary lavas are derived in part from an ancient crustal component with model ages between 1.1 _ 109 and 1.8 _ 109 years and from a peridotitic end-member close to present-day oceanic mantle.

  15. Osmium complexation of mismatched DNA: effect of the bases adjacent to mismatched 5-methylcytosine.

    PubMed

    Nomura, Akiko; Tainaka, Kazuki; Okamoto, Akimitsu

    2009-03-18

    The efficiency of osmium complex formation at 5-methylcytosine in mismatched DNA duplexes is a key point for the design of sequence-specific detection of DNA methylation. Osmium complexation was not observed in fully matched duplexes, whereas the complexation site and efficiency in mismatched duplexes changed depending on the type of 5'-neighboring base of the 5-methylcytosine forming a mismatched base pair. In particular, when the base adjacent to the 5' side of the mismatched base pair was thymine, a unique "side reaction" was observed. However, the nature of the mismatched base pairs in the reaction site did not influence the selectivity of osmium complex formation with methylated DNA.

  16. 21 CFR 820.186 - Quality system record.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Quality system record. 820.186 Section 820.186...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Records § 820.186 Quality system record. Each manufacturer shall maintain a quality system record (QSR). The QSR shall include, or refer to the location of, procedures...

  17. 21 CFR 820.186 - Quality system record.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Quality system record. 820.186 Section 820.186...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Records § 820.186 Quality system record. Each manufacturer shall maintain a quality system record (QSR). The QSR shall include, or refer to the location of, procedures...

  18. 21 CFR 820.186 - Quality system record.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Quality system record. 820.186 Section 820.186...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Records § 820.186 Quality system record. Each manufacturer shall maintain a quality system record (QSR). The QSR shall include, or refer to the location of, procedures...

  19. 21 CFR 820.186 - Quality system record.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Quality system record. 820.186 Section 820.186...) MEDICAL DEVICES QUALITY SYSTEM REGULATION Records § 820.186 Quality system record. Each manufacturer shall maintain a quality system record (QSR). The QSR shall include, or refer to the location of, procedures...

  20. 46 CFR 502.186 - Contents of memoranda.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 9 2013-10-01 2013-10-01 false Contents of memoranda. 502.186 Section 502.186 Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS RULES OF PRACTICE AND PROCEDURE Shortened Procedure § 502.186 Contents of memoranda. The memorandum should contain concise arguments and fact, the same as would be offered if a...

  1. 33 CFR 110.186 - Port Everglades, Florida.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 33 Navigation and Navigable Waters 1 2012-07-01 2012-07-01 false Port Everglades, Florida. 110.186 Section 110.186 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.186 Port Everglades, Florida. (a) The anchorage grounds. The anchorage grounds, the center of...

  2. 33 CFR 110.186 - Port Everglades, Florida.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 33 Navigation and Navigable Waters 1 2014-07-01 2014-07-01 false Port Everglades, Florida. 110.186 Section 110.186 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.186 Port Everglades, Florida. (a) The anchorage grounds. The anchorage grounds, the center of...

  3. 33 CFR 110.186 - Port Everglades, Florida.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 33 Navigation and Navigable Waters 1 2013-07-01 2013-07-01 false Port Everglades, Florida. 110.186 Section 110.186 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY ANCHORAGES ANCHORAGE REGULATIONS Anchorage Grounds § 110.186 Port Everglades, Florida. (a) The anchorage grounds. The anchorage grounds, the center of...

  4. 46 CFR 502.186 - Contents of memoranda.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Contents of memoranda. 502.186 Section 502.186 Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS RULES OF PRACTICE AND PROCEDURE Shortened Procedure § 502.186 Contents of memoranda. The memorandum should contain concise arguments and fact, the same as would be offered if a...

  5. 21 CFR 820.186 - Quality system record.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Quality system record. 820.186 Section 820.186 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES QUALITY SYSTEM REGULATION Records § 820.186 Quality system record. Each manufacturer...

  6. Osmium tetroxide as a probe of RNA structure.

    PubMed

    Zhang, Jing; Li, Danbin; Zhang, Jun; Chen, Dongrong; Murchie, Alastair I H

    2017-04-01

    Structured RNAs have a central role in cellular function. The capability of structured RNAs to adopt fixed architectural structures or undergo dynamic conformational changes contributes to their diverse role in the regulation of gene expression. Although numerous biophysical and biochemical tools have been developed to study structured RNAs, there is a continuing need for the development of new methods for the investigation of RNA structures, especially methods that allow RNA structure to be studied in solution close to its native cellular conditions. Here we use osmium tetroxide (OsO4) as a chemical probe of RNA structure. In this method, we have used fluorescence-based sequencing technologies to detect OsO4 modified RNA. We characterized the requirements for OsO4 modification of RNA by investigating three known structured RNAs: the M-box, glycine riboswitch RNAs, and tRNA(asp) Our results show that OsO4 predominantly modifies RNA at uracils that are conformationally exposed on the surface of the RNA. We also show that changes in OsO4 reactivity at flexible positions in the RNA correlate with ligand-driven conformational changes in the RNA structure. Osmium tetroxide modification of RNA will provide insights into the structural features of RNAs that are relevant to their underlying biological functions.

  7. Investigation of 186Re via radiative thermal-neutron capture on 185Re

    NASA Astrophysics Data System (ADS)

    Matters, D. A.; Lerch, A. G.; Hurst, A. M.; Szentmiklósi, L.; Carroll, J. J.; Detwiler, B.; Révay, Zs.; McClory, J. W.; McHale, S. R.; Firestone, R. B.; Sleaford, B. W.; Krtička, M.; Belgya, T.

    2016-05-01

    Partial γ -ray production cross sections and the total radiative thermal-neutron capture cross section for the 185Re(n ,γ ) 186Re reaction were measured using the Prompt Gamma Activation Analysis facility at the Budapest Research Reactor with an enriched 185Re target. The 186Re cross sections were standardized using well-known 35Cl(n ,γ )36Cl cross sections from irradiation of a stoichiometric natReCl3 target. The resulting cross sections for transitions feeding the 186Re ground state from low-lying levels below a cutoff energy of Ec=746 keV were combined with a modeled probability of ground-state feeding from levels above Ec to arrive at a total cross section of σ0=111 (6 ) b for radiative thermal-neutron capture on 185Re. A comparison of modeled discrete-level populations with measured transition intensities led to proposed revisions for seven tentative spin-parity assignments in the adopted level scheme for 186Re. Additionally, 102 primary γ rays were measured, including 50 previously unknown. A neutron-separation energy of Sn=6179.59 (5 ) keV was determined from a global least-squares fit of the measured γ -ray energies to the known 186Re decay scheme. The total capture cross section and separation energy results are comparable to earlier measurements of these values.

  8. Recent advances in osmium-catalyzed hydrogenation and dehydrogenation reactions.

    PubMed

    Chelucci, Giorgio; Baldino, Salvatore; Baratta, Walter

    2015-02-17

    CONSPECTUS: A current issue in metal-catalyzed reactions is the search for highly efficient transition-metal complexes affording high productivity and selectivity in a variety of processes. Moreover, there is also a great interest in multitasking catalysts that are able to efficiently promote different organic transformations by careful switching of the reaction parameters, such as temperature, solvent, and cocatalyst. In this context, osmium complexes have shown the ability to catalyze efficiently different types of reactions involving hydrogen, proving at the same time high thermal stability and simple synthesis. In the catalytic reduction of C═X (X = O, N) bonds by both hydrogenation (HY) and transfer hydrogenation (TH) reactions, the most interest has been focused on homogeneous systems based on rhodium, iridium, and in particular ruthenium catalysts, which have proved to catalyze chemo- and stereoselective hydrogenations with remarkable efficiency. By contrast, osmium catalysts have received much less attention because they are considered less active on account of their slower ligand exchange kinetics. Thus, this area remained almost neglected until recent studies refuted these prejudices. The aim of this Account is to highlight the impressive developments achieved over the past few years by our and other groups on the design of new classes of osmium complexes and their applications in homogeneous catalytic reactions involving the hydrogenation of carbon-oxygen and carbon-nitrogen bonds by both HY and TH reactions as well as in alcohol deydrogenation (DHY) reactions. The work described in this Account demonstrates that osmium complexes are emerging as powerful catalysts for asymmetric and non-asymmetric syntheses, showing a remarkably high catalytic activity in HY and TH reactions of ketones, aldehydes, imines, and esters as well in DHY reactions of alcohols. Thus, for instance, the introduction of ligands with an NH function, possibly in combination with a

  9. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    DOEpatents

    Corbea, Javier Jesus Concepcion; Chen, Zoufeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2016-06-07

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  10. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    SciTech Connect

    Concepcion Corbea, Javier Jesus; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L; Hoertz, Paul; Meyer, Thomas J

    2014-10-28

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  11. Ruthenium or osmium complexes and their uses as catalysts for water oxidation

    SciTech Connect

    Corbea, Javier Jesus Concepcion; Chen, Zuofeng; Jurss, Jonah Wesley; Templeton, Joseph L.; Hoertz, Paul; Meyer, Thomas J.

    2013-09-03

    The present invention provides ruthenium or osmium complexes and their uses as a catalyst for catalytic water oxidation. Another aspect of the invention provides an electrode and photo-electrochemical cells for electrolysis of water molecules.

  12. Organometallic osmium(II) arene anticancer complexes containing picolinate derivatives.

    PubMed

    van Rijt, Sabine H; Peacock, Anna F A; Johnstone, Russell D L; Parsons, Simon; Sadler, Peter J

    2009-02-16

    Chlorido osmium(II) arene [(eta(6)-biphenyl)Os(II)(X-pico)Cl] complexes containing X = Br (1), OH (2), and Me (3) as ortho, or X = Cl (4), CO(2)H (5), and Me (6) as para substituents on the picolinate (pico) ring have been synthesized and characterized. The X-ray crystal structures of 1 and 6 show typical "piano-stool" geometry with intermolecular pi-pi stacking of the biphenyl outer rings of 6. At 288 K the hydrolysis rates follow the order 2 > 6 > 4 > 3 > 5 > 1 with half-lives ranging from minutes to 4.4 h illustrating the influence of both electronic and steric effects of the substituents. The pK(a) values of the aqua adducts 3A, 4A, 5A, and 6A were all in the range of 6.3-6.6. The para-substituted pico complexes 4-6 readily formed adducts with both 9-ethyl guanine (9EtG) and 9-ethyl adenine (9EtA), but these were less favored for the ortho-substituted complexes 1 and 3 showing little reaction with 9EtG and 9EtA, respectively. Density-functional theory calculations confirmed the observed preferences for nucleobase binding for complex 1. In cytotoxicity assays with A2780, cisplatin-resistant A2780cis human ovarian, A549 human lung, and HCT116 colon cancer cells, only complexes 4 (p-Cl) and 6 (p-Me) exhibited significant activity (IC(50) values < 25 microM). Both of these complexes were as active as cisplatin in A2780 (ovarian) and HCT116 (colon) cell lines, and even overcome cisplatin resistance in the A2780cis (ovarian) cell line. The inactivity of 5 is attributed to the negative charge on its para carboxylate substituent. These data illustrate how the chemical reactivity and cancer cell cytotoxicity of osmium arene complexes can be controlled and "fine-tuned" by the use of steric and electronic effects of substituents on a chelating ligand to give osmium(II) arene complexes which are as active as cisplatin but have a different mechanism of action.

  13. Neutronic effects on tungsten-186 double neutron capture

    NASA Astrophysics Data System (ADS)

    Garland, Marc Alan

    Rhenium-188, a daughter product of tungsten-188, is an isotope of great interest in therapeutic nuclear medicine, being used in dozens of laboratory and clinical investigations worldwide. Applications include various cancer therapy strategies, treatment of rheumatoid arthritis, prevention of restenosis following coronary artery angioplasty, and palliation of bone pain associated with cancer metastases. With its half-life of 17 hours, 2.12 MeV (maximum) beta-particle emission, chemical similarity to technetium-99m (the most widely used diagnostic radioisotope), and its availability in a convenient tungsten-188/rhenium-188 generator system, rhenium-188 is a superb candidate for a broad range of applications. Production of 188W is typically via double neutron capture by 186W in a high flux nuclear reactor, predominantly the High Flux Isotope Reactor at the Oak Ridge National Laboratory in Tennessee. Experience at HFIR has shown that production yields (measured in Ci of 188W produced per g of 186W target) decrease considerably as target size increases. While the phenomenon of neutron resonance self-shielding would be expected to produce such an effect, temperature effects on neutron flux distribution and neutron capture rates may also be involved. Experimental investigations of these phenomena have not been previously performed. The work presented in this thesis evaluates the factors that contribute to the decrease in 188W yield from both theoretical and experimental standpoints. Neutron self-shielding and temperature effects were characterized to develop a strategy for target design that would optimize production yield, an important factor in minimizing health care costs. It was determined that decrease in yield due to neutron self-shielding can be attributed to depletion of epithermal neutrons at resonant energies, most significantly within the initial 0.4 mm depth of the target. The results from these studies further show that 188W yield in the interior of the

  14. Analysis of the Nuclear Structure of 186 Re Using Neutron-Induced Reactions

    NASA Astrophysics Data System (ADS)

    Matters, David; McClory, John; Carroll, James; Chiara, Chris; Fotiades, Nikolaos; Devlin, Matt; Nelson, Ron O.

    2015-04-01

    Evaluated nuclear structure data for 186 Re identifies the majority of spin-parity assignments as tentative, with approximate values associated with the energies of several levels and transitions. In particular, the absence of known transitions that feed the Jπ =8+ isomer motivates their discovery, which would have astrophysical implications and a potential application in the development of an isomer power source. Using the GErmanium Array for Neutron Induced Excitations (GEANIE) spectrometer at the Los Alamos Neutron Science Center (LANSCE) Weapons Neutron Research (WNR) facility, the (n,2n γ) and (n,n' γ) reactions in a 99.52% enriched 187 Re target were used to measure γ-ray excitation functions in 186 Re and 187 Re, respectively. A preliminary analysis of the data obtained from the experiment reveals several new transitions in 186 Re and 187 Re.

  15. Similar Biological Activities of Two Isostructural Ruthenium and Osmium Complexes

    SciTech Connect

    Maksimoska,J.; Williams, D.; Atilla-Gokcumen, G.; Smalley, K.; Carroll, P.; Webster, R.; Filippakopoulos, P.; Knapp, S.; Herlyn, M.; Meggers, E.

    2008-01-01

    In this study, we probe and verify the concept of designing unreactive bioactive metal complexes, in which the metal possesses a purely structural function, by investigating the consequences of replacing ruthenium in a bioactive half-sandwich kinase inhibitor scaffold by its heavier congener osmium. The two isostructural complexes are compared with respect to their anticancer properties in 1205?Lu melanoma cells, activation of the Wnt signaling pathway, IC50 values against the protein kinases GSK-3? and Pim-1, and binding modes to the protein kinase Pim-1 by protein crystallography. It was found that the two congeners display almost indistinguishable biological activities, which can be explained by their nearly identical three-dimensional structures and their identical mode of action as protein kinase inhibitors. This is a unique example in which the replacement of a metal in an anticancer scaffold by its heavier homologue does not alter its biological activity.

  16. PNP pincer osmium polyhydrides for catalytic dehydrogenation of primary alcohols.

    PubMed

    Bertoli, Marcello; Choualeb, Aldjia; Gusev, Dmitry G; Lough, Alan J; Major, Quinn; Moore, Brandon

    2011-09-21

    This paper reports the synthesis, structure, and properties of a series of PNP pincer complexes of osmium OsH(3)Cl[HN(C(2)H(4)P(i)Pr(2))(2)] (1), OsH(3)[N(C(2)H(4)P(i)Pr(2))(2)] (2), OsH(4)[HN(C(2)H(4)P(i)Pr(2))(2)] (3), and OsH(2)(PMe(3))[HN(C(2)H(4)P(i)Pr(2))(2)] (4). The tetrahydride 3 operates as an efficient catalyst at 0.1 mol% loading for the reactions of amination and dehydrogenative coupling of primary alcohols, producing secondary amines and symmetrical esters, respectively. The catalyst 3 is distinguished by outstanding stability, and it can be used in an aqueous environment at temperatures as high as 200 °C.

  17. Confirmation of a meteoritic component in impact-melt rocks of the Chesapeake Bay impact structure, Virginia, USA - Evidence from osmium isotopic and PGE systematics

    USGS Publications Warehouse

    Lee, S.R.; Horton, J.W.; Walker, R.J.

    2006-01-01

    The osmium isotope ratios and platinum-group element (PGE) concentrations of impact-melt rocks in the Chesapeake Bay impact structure were determined. The impact-melt rocks come from the cored part of a lower-crater section of suevitic crystalline-clast breccia in an 823 m scientific test hole over the central uplift at Cape Charles, Virginia. The 187Os/188Os ratios of impact-melt rocks range from 0.151 to 0.518. The rhenium and platinum-group element (PGE) concentrations of these rocks are 30-270?? higher than concentrations in basement gneiss, and together with the osmium isotopes indicate a substantial meteoritic component in some impact-melt rocks. Because the PGE abundances in the impact-melt rocks are dominated by the target materials, interelemental ratios of the impact-melt rocks are highly variable and nonchondritic. The chemical nature of the projectile for the Chesapeake Bay impact structure cannot be constrained at this time. Model mixing calculations between chondritic and crustal components suggest that most impact-melt rocks include a bulk meteoritic component of 0.01-0.1% by mass. Several impact-melt rocks with lowest initial 187Os/188Os ratios and the highest osmium concentrations could have been produced by additions of 0.1%-0.2% of a meteoritic component. In these samples, as much as 70% of the total Os may be of meteoritic origin. At the calculated proportions of a meteoritic component (0.01-0.1% by mass), no mixtures of the investigated target rocks and sediments can reproduce the observed PGE abundances of the impact-melt rocks, suggesting that other PGE enrichment processes operated along with the meteoritic contamination. Possible explanations are 1) participation of unsampled target materials with high PGE abundances in the impact-melt rocks, and 2) variable fractionations of PGE during syn- to post-impact events. ?? The Meteoritical Society, 2006.

  18. 21 CFR 133.186 - Sap sago cheese.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Sap sago cheese. 133.186 Section 133.186 Food and... Products § 133.186 Sap sago cheese. (a) Description. (1) Sap sago cheese is the food prepared by the... method described in § 133.5. Sap sago cheese is not less than 5 months old. (2) One or more of the...

  19. 21 CFR 133.186 - Sap sago cheese.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Sap sago cheese. 133.186 Section 133.186 Food and... Products § 133.186 Sap sago cheese. (a) Description. (1) Sap sago cheese is the food prepared by the... method described in § 133.5. Sap sago cheese is not less than 5 months old. (2) One or more of the...

  20. 21 CFR 133.186 - Sap sago cheese.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Sap sago cheese. 133.186 Section 133.186 Food and... Products § 133.186 Sap sago cheese. (a) Description. (1) Sap sago cheese is the food prepared by the... method described in § 133.5. Sap sago cheese is not less than 5 months old. (2) One or more of the...

  1. 21 CFR 133.186 - Sap sago cheese.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Sap sago cheese. 133.186 Section 133.186 Food and... Products § 133.186 Sap sago cheese. (a) Description. (1) Sap sago cheese is the food prepared by the... method described in § 133.5. Sap sago cheese is not less than 5 months old. (2) One or more of the...

  2. Osmium isotope variations in the oceans recorded by Fe-Mn crusts

    USGS Publications Warehouse

    Burton, K.W.; Bourdon, B.; Birck, J.-L.; Allegre, C.J.; Hein, J.R.

    1999-01-01

    This study presents osmium (Os) isotope data for recent growth surfaces of hydrogenetic ferromanganese (Fe-Mn) crusts from the Pacific, Atlantic and Indian Oceans. In general, these data indicate a relatively uniform Os isotopic composition for modern seawater, but suggest that North Atlantic seawater is slightly more radiogenic than that of the Pacific and Indian Oceans. The systematic difference in the Os isotopic composition between the major oceans probably reflects a greater input of old continental material with a high Re/Os ratio in the North Atlantic Ocean, consistent with the distribution of Nd and Pb isotopes. This spatial variation in the Os isotope composition in seawater is consistent with a residence time for Os of between 2 and 60 kyr. Indian Ocean samples show no evidence of a local source of radiogenic Os, which suggests that the present-day riverine input from the Himalaya-Tibet region is not a major source for Os. Recently formed Fe-Mn crusts from the TAG hydrothermal field in the North Atlantic yield an Os isotopic composition close to that of modern seawater, which indicates that, in this area, the input of unradiogenic Os from the hydrothermal alteration of oceanic crust is small. However, some samples from the deep Pacific (???4 km) possess a remarkably unradiogenic Os isotope composition (187Os/186Os ratios as low as 4.3). The compositional control of Os incorporation into the crusts and mixing relationships suggest that this unradiogenic composition is most likely due to the direct incorporation of micrometeoritic or abyssal peridotite particles, rather than indicating the presence of an unradiogenic deep-water mass. Moreover, this unradiogenic signal appears to be temporary, and local, and has had little apparent effect on the overall evolution of seawater. These results confirm that input of continental material through erosion is the dominant source of Os in seawater, but it is not clear whether global Os variations are due to the input

  3. Anticancer osmium complex inhibitors of the HIF-1α and p300 protein-protein interaction

    PubMed Central

    Yang, Chao; Wang, Wanhe; Li, Guo-Dong; Zhong, Hai-Jing; Dong, Zhen-Zhen; Wong, Chun-Yuen; Kwong, Daniel W. J.; Ma, Dik-Lung; Leung, Chung-Hang

    2017-01-01

    The hypoxia inducible factor (HIF) pathway has been considered to be an attractive anti-cancer target. One strategy to inhibit HIF activity is through the disruption of the HIF-1α–p300 protein-protein interaction. We report herein the identification of an osmium(II) complex as the first metal-based inhibitor of the HIF-1α–p300 interaction. We evaluated the effect of complex 1 on HIF-1α signaling pathway in vitro and in cellulo by using the dual luciferase reporter assay, co-immunoprecipitation assay, and immunoblot assay. Complex 1 exhibited a dose-dependent inhibition of HRE-driven luciferase activity, with an IC50 value of 1.22 μM. Complex 1 interfered with the HIF-1α–p300 interaction as revealed by a dose-dependent reduction of p300 co-precipitated with HIF-1α as the concentration of complex 1 was increased. Complex 1 repressed the phosphorylation of SRC, AKT and STAT3, and had no discernible effect on the activity of NF-κB. We anticipate that complex 1 could be utilized as a promising scaffold for the further development of more potent HIF-1α inhibitors for anti-cancer treatment. PMID:28225008

  4. Search for a meteoritic component in impact-melt rocks from the Lonar crater, India - Evidence from osmium isotope systematics

    NASA Astrophysics Data System (ADS)

    Schulz, T.; Luguet, A.; Koeberl, C.

    2013-12-01

    Introduction: The Lonar crater in western India (Maharashtra) is a bowl-shaped simple impact structure of 1830 m diameter and a depth of 120 m below the rim crest. The crater formed 0.656 × 0.081 Ma ago on the 65 Ma old basaltic lava flows of the Deccan Traps (Jourdan et al. 2010) and is one of the few terrestrial impact structures to have formed in basaltic host-rocks. In the absence of actual meteorite fragments, the impact origin of this structure was supported by the identification of a variety of shock metamorphic features (e.g. Fredriksson et al. 1973). However, clear indications of an extraterrestrial component in impactites based on geochemical studies are absent or remained ambiguous so far (e.g. Osae et al. 2005). As the Os isotope tool has the potential to provide firm constraints on the presence or absence of even very small (<<1%) contributions of meteoritic matter to impactite lithologies (e.g. Koeberl et al. 2002), we conduct a detailed Os isotope study of a variety of unshocked host-basalts (target rocks) and impactites (impact-melt rocks) from the Lonar crater. Samples and Method: All samples analyzed in this study were collected in 2000 and 2001 and were geochemically characterized by Osae et al. (2005). Osmium (and additional PGE) analyses were performed on about 2 g whole rock powders, which were spiked with a mixed 190Os,185Re,191Ir,194Pt tracer, and digested via high pressure Asher using inverse aqua regia. Osmium solvent extraction and microdistillation were performed as described by Cohen and Waters (1996). Osmium isotopic compositions were measured using a TRITON N-TIMS at the Department of Lithospheric Research in Vienna. Results and Discussion: Osmium data on seven target and nine impact melt rocks reveal 187Os/188Os ratios ranging from ~0.38 to ~2.23 for the target rocks and from ~0.22 to ~0.59 for the nine analyzed impact melt rocks, whereas Os concentrations range from ~7.1 to ~31.6 ppt and ~7.2 to ~134 ppt, respectively. Although in

  5. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance with... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Method of Application. 18.6 Section...

  6. 21 CFR 186.1551 - Hydrogenated fish oil.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Hydrogenated fish oil. 186.1551 Section 186.1551 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS SAFE Listing of Specific Substances...

  7. 21 CFR 186.1551 - Hydrogenated fish oil.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Hydrogenated fish oil. 186.1551 Section 186.1551 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS...

  8. 21 CFR 186.1551 - Hydrogenated fish oil.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 3 2011-04-01 2011-04-01 false Hydrogenated fish oil. 186.1551 Section 186.1551 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS...

  9. 21 CFR 186.1551 - Hydrogenated fish oil.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 3 2012-04-01 2012-04-01 false Hydrogenated fish oil. 186.1551 Section 186.1551 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS...

  10. 21 CFR 186.1551 - Hydrogenated fish oil.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 3 2013-04-01 2013-04-01 false Hydrogenated fish oil. 186.1551 Section 186.1551 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION (CONTINUED) INDIRECT FOOD SUBSTANCES AFFIRMED AS GENERALLY RECOGNIZED AS...

  11. 27 CFR 555.186 - Seizure or forfeiture.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2010-04-01 2010-04-01 false Seizure or forfeiture. 555.186 Section 555.186 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND... Seizure or forfeiture. Any plastic explosive that does not contain a detection agent in violation of 18...

  12. 27 CFR 555.186 - Seizure or forfeiture.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 3 2011-04-01 2010-04-01 true Seizure or forfeiture. 555.186 Section 555.186 Alcohol, Tobacco Products, and Firearms BUREAU OF ALCOHOL, TOBACCO, FIREARMS, AND... Seizure or forfeiture. Any plastic explosive that does not contain a detection agent in violation of 18...

  13. 27 CFR 44.186 - Tax classification for cigars.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2012-04-01 2011-04-01 true Tax classification for cigars. 44.186 Section 44.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE... PAPERS AND TUBES, WITHOUT PAYMENT OF TAX, OR WITH DRAWBACK OF TAX Removal of Shipments of...

  14. 5 CFR 550.186 - Relationship to other payments.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Section 550.186 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.186 Relationship to other payments... retirement benefits; and (8) For any other purposes explicitly provided for by law or as the Office...

  15. 5 CFR 550.186 - Relationship to other payments.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Section 550.186 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.186 Relationship to other payments... retirement benefits; and (8) For any other purposes explicitly provided for by law or as the Office...

  16. 5 CFR 550.186 - Relationship to other payments.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Section 550.186 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.186 Relationship to other payments... retirement benefits; and (8) For any other purposes explicitly provided for by law or as the Office...

  17. 5 CFR 550.186 - Relationship to other payments.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Section 550.186 Administrative Personnel OFFICE OF PERSONNEL MANAGEMENT CIVIL SERVICE REGULATIONS PAY ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.186 Relationship to other payments... retirement benefits; and (8) For any other purposes explicitly provided for by law or as the Office...

  18. 27 CFR 53.186 - Accounting procedures for like articles.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... like articles. 53.186 Section 53.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Accounting procedures for like articles. (a) Identification of manufacturer. In applying section 6416 of the Code and the regulations thereunder, a person who has purchased like articles from...

  19. 27 CFR 53.186 - Accounting procedures for like articles.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... like articles. 53.186 Section 53.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Accounting procedures for like articles. (a) Identification of manufacturer. In applying section 6416 of the Code and the regulations thereunder, a person who has purchased like articles from...

  20. 27 CFR 53.186 - Accounting procedures for like articles.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... like articles. 53.186 Section 53.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Accounting procedures for like articles. (a) Identification of manufacturer. In applying section 6416 of the Code and the regulations thereunder, a person who has purchased like articles from...

  1. 27 CFR 53.186 - Accounting procedures for like articles.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... like articles. 53.186 Section 53.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND... Accounting procedures for like articles. (a) Identification of manufacturer. In applying section 6416 of the Code and the regulations thereunder, a person who has purchased like articles from...

  2. 31 CFR 103.186 - Special measures against Burma.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Special measures against Burma. 103.186 Section 103.186 Money and Finance: Treasury Regulations Relating to Money and Finance FINANCIAL RECORDKEEPING AND REPORTING OF CURRENCY AND FOREIGN TRANSACTIONS Anti-Money Laundering Programs Law...

  3. 40 CFR 60.186 - Test methods and procedures.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 7 2014-07-01 2014-07-01 false Test methods and procedures. 60.186... Smelters § 60.186 Test methods and procedures. (a) In conducting the performance tests required in § 60.8, the owner or operator shall use as reference methods and procedures the test methods in appendix A...

  4. 40 CFR 60.186 - Test methods and procedures.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Test methods and procedures. 60.186... Smelters § 60.186 Test methods and procedures. (a) In conducting the performance tests required in § 60.8, the owner or operator shall use as reference methods and procedures the test methods in appendix A...

  5. 40 CFR 60.186 - Test methods and procedures.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Test methods and procedures. 60.186... Smelters § 60.186 Test methods and procedures. (a) In conducting the performance tests required in § 60.8, the owner or operator shall use as reference methods and procedures the test methods in appendix A...

  6. 21 CFR 211.186 - Master production and control records.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Master production and control records. 211.186... Reports § 211.186 Master production and control records. (a) To assure uniformity from batch to batch, master production and control records for each drug product, including each batch size thereof, shall...

  7. Single-Site Osmium Catalysts on MgO: Reactivity and Catalysis of CO Oxidation.

    PubMed

    Yang, Dong; Zhang, Shengjie; Xu, Pinghong; Browning, Nigel D; Dixon, David A; Gates, Bruce C

    2017-02-21

    MgO-supported osmium dioxo species, described as Os(=O)2 {-Osupport }1 or 2 (the brackets denote O atoms of the MgO surface), formed from Os3 (CO)12 via supported Os(CO)2 , and characterized by spectroscopy, microscopy, and theory, react with ethylene at 298 K to form osmium glycol species or with CO to give osmium mono- and di-carbonyls. Os(=O)2 {-Osupport }1 or 2 is the precursor of a CO oxidation catalyst characterized by a turnover frequency of 4.0×10(-3) (molecules of CO)/(Os atom×s) at 473 K; the active species are inferred to be osmium monocarbonyls. The structures and frequencies calculated at the level of density functional theory with the B3LYP functional bolster the experimental results and facilitate structural assignments. The lowest-energy structures have various osmium oxidation and spin states. The results demonstrate not only new chemistry of the supported single-site catalysts but also their complexity and the value of complementary techniques used in concert to unravel the chemistry.

  8. Sequential separation and spectrophotometric determination of osmium and platinum with 5-chloro-2-hydroxythiobenzhydrazide.

    PubMed

    Sawant, Shakuntala S

    2009-06-01

    Osmium was determined spectrophotometrically after coprecipitation with 5-chloro-2-hydroxythiobenzhydrazide at room temperature in the pH range 2.5-5.0 and collection on microcrystalline naphthalene. Beer's law was obeyed in the concentration range 1.8-14.4 ppm of osmium in a chloroform solution at 510 nm. The molar absorptivity and Sandell sensitivity were 1.056 x 10(4) l mol(-1) cm(-1) and 0.018 ppm, respectively. Six replicate analyses of a solution containing 7.2 ppm of osmium gave a mean absorbance of 0.405 with a standard deviation of 0.013 and a relative standard deviation of 0.92%. The complex was stable for over 72 h. The metal-to-ligand ratio in the complex was 1:2. Interference from various ions was studied, and the method was applied to the determination of osmium in various synthetic mixtures containing commonly associated metals and corresponding to the alloy composition. The sequential separation and determination of osmium and platinum is reported.

  9. Osmium isotope evidence for a large Late Triassic impact event

    PubMed Central

    Sato, Honami; Onoue, Tetsuji; Nozaki, Tatsuo; Suzuki, Katsuhiko

    2013-01-01

    Anomalously high platinum group element concentrations have previously been reported for Upper Triassic deep-sea sediments, which are interpreted to be derived from an extraterrestrial impact event. Here we report the osmium (Os) isotope fingerprint of an extraterrestrial impact from Upper Triassic chert successions in Japan. Os isotope data exhibit a marked negative excursion from an initial Os isotope ratio (187Os/188Osi) of ∼0.477 to unradiogenic values of ∼0.126 in a platinum group element-enriched claystone layer, indicating the input of meteorite-derived Os into the sediments. The timing of the Os isotope excursion coincides with both elevated Os concentrations and low Re/Os ratios. The magnitude of this negative Os isotope excursion is comparable to those found at Cretaceous–Paleogene boundary sites. These geochemical lines of evidence demonstrate that a large impactor (3.3–7.8 km in diameter) produced a global decrease in seawater 187Os/188Os ratios in the Late Triassic. PMID:24036603

  10. Osmium isotope stratigraphy of a marine ferromanganese crust

    USGS Publications Warehouse

    Klemm, V.; Levasseur, S.; Frank, M.; Hein, J.R.; Halliday, A.N.

    2005-01-01

    Ferromanganese crusts provide records of long term change in ocean circulation and continental weathering. However, calibrating their age prior to 10 Ma has been entirely based on empirical growth rate models using Co concentrations, which have inherently large uncertainties and fail to detect hiatuses and erosional events. We present a new method for dating these crusts by measuring their osmium (Os) isotope record and matching it to the well-known marine Os isotope evolution of the past 80 Ma. The well-characterised crust CD29-2 from the central Pacific, was believed to define a record of paleooceanographic change from 50 Ma. Previous growth rate estimates based on the Co method are consistent with the new Os isotope stratigraphy but the dating was grossly inaccurate due to long hiatuses that are now detectable. The new chronology shows that it in fact started growing prior to 70 Ma in the late Cretaceous and stopped growing or was eroded between 13.5 and 47 Ma. With this new technique it is now possible to exploit the full potential of the oceanographic and climatic records stored in Fe-Mn crusts. ?? 2005 Elsevier B.V. All rights reserved.

  11. Osmium isotope evidence for a large Late Triassic impact event.

    PubMed

    Sato, Honami; Onoue, Tetsuji; Nozaki, Tatsuo; Suzuki, Katsuhiko

    2013-01-01

    Anomalously high platinum group element concentrations have previously been reported for Upper Triassic deep-sea sediments, which are interpreted to be derived from an extraterrestrial impact event. Here we report the osmium (Os) isotope fingerprint of an extraterrestrial impact from Upper Triassic chert successions in Japan. Os isotope data exhibit a marked negative excursion from an initial Os isotope ratio ((187)Os/(188)Osi) of ~0.477 to unradiogenic values of ~0.126 in a platinum group element-enriched claystone layer, indicating the input of meteorite-derived Os into the sediments. The timing of the Os isotope excursion coincides with both elevated Os concentrations and low Re/Os ratios. The magnitude of this negative Os isotope excursion is comparable to those found at Cretaceous-Paleogene boundary sites. These geochemical lines of evidence demonstrate that a large impactor (3.3-7.8 km in diameter) produced a global decrease in seawater (187)Os/(188)Os ratios in the Late Triassic.

  12. Rhenium-osmium-isotope constraints on the age of iron meteorites

    NASA Technical Reports Server (NTRS)

    Horan, M. F.; Morgan, J. W.; Walker, R. J.; Grossman, J. N.

    1992-01-01

    Rhenium and osmium concentrations and the osmium isotopic compositions of iron meteorites were determined by negative thermal ionization mass spectrometry. Data for the IIA iron meteorites define an isochron with an uncertainty of approximately +/-31 million years for meteorites about 4500 million years old. Although an absolute rhenium-osmium closure age for this iron group cannot be as precisely constrained because of uncertainty in the decay constant of Re-187, an age of 4460 million years ago is the minimum permitted by combined uncertainties. These age constraints imply that the parent body of the IIAB magmatic irons melted and subsequently cooled within 100 million years after the formation of the oldest portions of chondrites. Other iron meteorites plot above the IIA isochron, indicating that the planetary bodies represented by these iron groups may have cooled significantly later than the parent body of the IIA irons.

  13. Rhenium-osmium isotope constraints on the age of iron meteorites

    USGS Publications Warehouse

    Horan, M.F.; Morgan, J.W.; Walker, R.J.; Grossman, J.N.

    1992-01-01

    Rhenium and osmium concentrations and the osmium isotopic compositions of iron meteorites were determined by negative thermal ionization mass spectrometry. Data for the IIA iron meteorites define an isochron with an uncertainty of approximately ??31 million years for meteorites ???4500 million years old. Although an absolute rhenium-osmium closure age for this iron group cannot be as precisely constrained because of uncertainty in the decay constant of 187Re, an age of 4460 million years ago is the minimum permitted by combined uncertainties. These age constraints imply that the parent body of the IIAB magmatic irons melted and subsequently cooled within 100 million years after the formation of the oldest portions of chondrites. Other iron meteorites plot above the IIA isochron, indicating that the planetary bodies represented by these iron groups may have cooled significantly later than the parent body of the IIA irons.

  14. Conduction electron g-factors in ruthenium and osmium from de Haas-van Alphen measurements

    NASA Astrophysics Data System (ADS)

    Startsev, V. E.; Coleridge, P. T.; Templeton, I. M.; Fawcett, E.; Muir, C.; Perz, J. M.

    1984-04-01

    Conduction electron g-factors have been deduced from de Haas-van Alphen line shapes in the hexagonal group VIII 4 d transition metal ruthenium and the electronically analogous 5 d metal osmium. The values for orbits normal to [0001] are 1.8±0.1 and 1.3±0.1 for the ellipsoids centered on the line LM in ruthenium and osmium, respectively, and 1.9±0.2 for the Γ-centered ellipsoid in ruthenium. The more marked suppression of the g-factor in osmium, where spin-orbit coupling is stronger, is consistent with recent theoretical studies of transition metal g-factor trends.

  15. Measurement of 230Pa and 186Re Production Cross Sections Induced by Deuterons at Arronax Facility

    NASA Astrophysics Data System (ADS)

    Duchemin, Charlotte; Guertin, Arnaud; Metivier, Vincent; Haddad, Ferid; Michel, Nathalie

    2014-02-01

    A dedicated program has been launched on production of innovative radionuclides for PET imaging and for β- and α targeted radiotherapy using proton or α particles at the ARRONAX cyclotron. Since the accelerator is also able to deliver deuteron beams up to 35 MeV, we have reconsidered the possibility of using them to produce medical isotopes. Two isotopes dedicated to targeted therapy have been considered: 226Th, a decay product of 230Pa, and 186Re. The production cross sections of 230Pa and 186Re, as well as those of the contaminants created during the irradiation, have been determined by the stacked-foil technique using deuteron beams. Experimental values have been quantified using a referenced cross section. The measured cross sections have been used to determine expected production yields and compared with the calculated values obtained using the Talys code with default parameters.

  16. Spectrophotometric determination of hydrogen peroxide with osmium(VIII) and m-carboxyphenylfluorone

    NASA Astrophysics Data System (ADS)

    Hoshino, Mitsuru; Kamino, Shinichiro; Doi, Mitsunobu; Takada, Shingo; Mitani, Shota; Yanagihara, Rika; Asano, Mamiko; Yamaguchi, Takako; Fujita, Yoshikazu

    2014-01-01

    Spectrophotometric determination of hydrogen peroxide was accomplished with osmium(VIII) and m-carboxyphenylfluorone (MCPF) in the presence of cetyltrimethylammonium chloride (CTAC). In the determination of hydrogen peroxide based on the fading of the color of osmium(VIII)-MCPF complex, Beer's law was obeyed in the range 20-406 ng mL-1, with an effective molar absorption coefficient (at 580 nm) of 5.21 × 104 L mol-1 cm-1 and a relative standard deviation of 0.33% (n = 6). Further, we performed the characterization of MCPF and obtained the crystal structure.

  17. Chitosan-cross-linked osmium polymer composites as an efficient platform for electrochemical biosensors.

    PubMed

    Jirimali, Harishchandra Digambar; Nagarale, Rajaram Krishna; Lee, Jong Myung; Saravanakumar, Durai; Shin, Woonsup

    2013-07-22

    A new family of chitosan-cross-linked osmium polymer composites was prepared and its electrochemical properties were examined. The composites were prepared by quaternization of the poly(4-vinylpyridine) osmium bipyridyl polymer (PVP-Os) which was then cross-linked with chitosan, yielding PVP-Os/chitosan. Films made of the composites showed improved mass and electron transport owing to the porous and hydrophilic structure which is derived from the cross-links between the Os polymer and chitosan. The rate for glucose oxidation was enhanced four times when glucose oxidase (GOx) was immobilized on PVP-Os/chitosan compared immobilization on PVP-Os.

  18. Low earth orbit environmental effects on osmium and related optical thin-film coatings

    NASA Technical Reports Server (NTRS)

    Gull, T. R.; Herzig, H.; Osantowski, J. F.; Toft, A. R.

    1985-01-01

    A number of samples of optical thin film materials were flown on Shuttle flight STS-8 as part of an experiment to evaluate their interaction with residual atomic oxygen in low earth orbit. Osmium was selected because of its usefulness as a reflective optical coating for far-UV instruments and for confirmation of results from previous Shuttle flights in which such coatings disappeared. Reflectance data and photographic evidence are presented to support the hypothesis that the osmium disappearance is due to reaction with oxygen to form a volatile oxide. Platinum and iridium, which were included for comparison, fared much better.

  19. Spectrophotometric determination of hydrogen peroxide with osmium(VIII) and m-carboxyphenylfluorone.

    PubMed

    Hoshino, Mitsuru; Kamino, Shinichiro; Doi, Mitsunobu; Takada, Shingo; Mitani, Shota; Yanagihara, Rika; Asano, Mamiko; Yamaguchi, Takako; Fujita, Yoshikazu

    2014-01-03

    Spectrophotometric determination of hydrogen peroxide was accomplished with osmium(VIII) and m-carboxyphenylfluorone (MCPF) in the presence of cetyltrimethylammonium chloride (CTAC). In the determination of hydrogen peroxide based on the fading of the color of osmium(VIII)-MCPF complex, Beer's law was obeyed in the range 20-406 ng mL(-1), with an effective molar absorption coefficient (at 580 nm) of 5.21×10(4) L mol(-1) cm(-1) and a relative standard deviation of 0.33% (n=6). Further, we performed the characterization of MCPF and obtained the crystal structure.

  20. Wiring of pyranose dehydrogenase with osmium polymers of different redox potentials.

    PubMed

    Zafar, Muhammad Nadeem; Tasca, Federico; Boland, Susan; Kujawa, Magdalena; Patel, Ilabahen; Peterbauer, Clemens K; Leech, Dónal; Gorton, Lo

    2010-11-01

    In this study, five different flexible osmium based redox polymers were investigated for their ability to efficiently "wire" the oxidoreductase pyranose dehydrogenase (PDH, EC 1.1.99.29) from Agaricus meleagris, on graphite electrodes for possible applications in biofuel cells. A series of newly synthesised osmium based redox polymers covering the potential range between -270 and +160 mV vs. Ag|AgCl (0.1M KCl) was used. The performance of the redox polymers for enzyme wiring was investigated using glucose as substrate. The optimal operational conditions such as pH and potential were investigated.

  1. Conductive polymers derived from iron, ruthenium, and osmium metalloporphyrins: The shish-kebab approach

    PubMed Central

    Collman, James P.; McDevitt, John T.; Yee, Gordon T.; Leidner, Charles R.; McCullough, Laughlin G.; Little, William A.; Torrance, Jerry B.

    1986-01-01

    The synthesis and characterization of pyrazine-bridged polymers of iron(II/III), ruthenium(II/III), and osmium(II/III) octaethylporphyrin (dubbed “shish-kebab” polymers) are presented. Optical and dc conductivity measurements reveal that the ruthenium and osmium polymers, when partially oxidized, are highly conductive. Electrochemical and ESR results are presented that indicate the existence of an interesting metal-centered conduction pathway. Unlike most of the previously reported porphyrinic molecular metals in which the conduction electrons are macrocyclic-based, electron transport in these materials proceeds exclusively along the metal-pyrazine backbone. PMID:16593717

  2. Osmium isotopic evidence for ancient subcontinental lithospheric mantle beneath the kerguelen islands, southern indian ocean

    PubMed

    Hassler; Shimizu

    1998-04-17

    Upper mantle xenoliths found in ocean island basalts are an important window through which the oceanic mantle lithosphere may be viewed directly. Osmium isotopic data on peridotite xenoliths from the Kerguelen Islands, an archipelago that is located on the northern Kerguelen Plateau in the southern Indian Ocean, demonstrate that pieces of mantle of diverse provenance are present beneath the Islands. In particular, peridotites with unradiogenic osmium and ancient rhenium-depletion ages (to 1.36 x 10(9) years old) may be pieces of the Gondwanaland subcontinental lithosphere that were incorporated into the Indian Ocean lithosphere as a result of the rifting process.

  3. Optimization of sedimentation of tungsten on copper substrate for production of 186gRe via 186W(p,n) nuclear reaction: Feasibility of using high current, long irradiation

    NASA Astrophysics Data System (ADS)

    Kakavand, T.; Mirzaii, M.; Khaleghi, M.; Eslami, M.

    2016-01-01

    Tungsten is recognized as one of the important metals used in cyclotron targets for production of several vital radioisotopes. Adequate adhesion of the prepared targets to its substrate is a significant parameter that makes them optimized for high current beam collisions. The target morphology should be paid special attention as another important parameter. In this work, a rather thick layer of tungsten is deposited on a copper substrate by sedimentation technique to produce 186gRe radionuclide via 186W(p,n) reaction. Consecutive sedimentation experiments are carried out to determine the best suspension solution. The prepared targets are evaluated in morphology by scanning electron microscope. A mixture of 1 g tungsten powder, 250 mg ethyl cellulose and 5 mL acetone is concluded for desirable target adhesion. Irradiation of the targets by 20 μA proton current (15 MeV energy) for 5 h shows that they can withstand the proton beam.

  4. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  5. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  6. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  7. 40 CFR 18.6 - Method of Application.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ....6 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL ENVIRONMENTAL PROTECTION RESEARCH FELLOWSHIPS AND SPECIAL RESEARCH CONSULTANTS FOR ENVIRONMENTAL PROTECTION § 18.6 Method of Application. Application for an Environmental Protection Research fellowship shall be made in accordance...

  8. 18 CFR 367.1860 - Account 186, Miscellaneous deferred debits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... NATURAL GAS ACT Balance Sheet Chart of Accounts Deferred Debits § 367.1860 Account 186, Miscellaneous... ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE PUBLIC UTILITY HOLDING...

  9. 40 CFR 417.186 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.186 Pretreatment standards for new sources. Any new source subject to...

  10. 40 CFR 417.186 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.186 Pretreatment standards for new sources. Any new source subject to...

  11. 40 CFR 417.186 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.186 Pretreatment standards for new sources. Any new source subject to...

  12. 40 CFR 417.186 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.186 Pretreatment standards for new sources. Any new source subject to...

  13. 40 CFR 417.186 - Pretreatment standards for new sources.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... GUIDELINES AND STANDARDS SOAP AND DETERGENT MANUFACTURING POINT SOURCE CATEGORY Manufacture of Drum Dried Detergents Subcategory § 417.186 Pretreatment standards for new sources. Any new source subject to...

  14. Evidence for an ancient osmium isotopic reservoir in Earth.

    PubMed

    Meibom, Anders; Frei, Robert

    2002-04-19

    Iridosmine grains from placer deposits associated with peridotite-bearing ophiolites in the Klamath mountains have extremely radiogenic 186Os/188Os ratios and old Re-Os minimum ages, from 256 to 2644 million years. This indicates the existence of an ancient platinum group element reservoir with a supra-chondritic Pt/Os ratio. Such a ratio may be produced in the outer core as a result of inner core crystallization that fractionates Os from Pt. However, if the iridosmine Os isotopic compositions are a signature of the outer core, then the inner core must have formed very early, within several hundred million years after the accretion of Earth.

  15. Facile synthesis of hydroxymethylcytosine-containing oligonucleotides and their reactivity upon osmium oxidation.

    PubMed

    Sugizaki, Kaori; Ikeda, Shuji; Yanagisawa, Hiroyuki; Okamoto, Akimitsu

    2011-06-07

    DNA strands containing a 5-hydroxymethylcytosine ((hm)C), which have recently been found in neuron cells and embryonic stem cells, were synthesized through a facile synthetic technique. The (hm)C-containing strands were efficiently oxidized at (hm)C using an osmium oxidation assay. The (hm)C was oxidized as easily as 5-methylcytosine, which can be distinguished from unmethylated cytosine.

  16. Synthesis and antitumor activity of a series of osmium(VI) nitrido complexes bearing quinolinolato ligands.

    PubMed

    Tang, Quan; Ni, Wen-Xiu; Leung, Chi-Fai; Man, Wai-Lun; Lau, Kenneth King-Kwan; Liang, Yimin; Lam, Yun-Wah; Wong, Wai-Yeung; Peng, Shie-Ming; Liu, Gui-Jian; Lau, Tai-Chu

    2013-11-04

    A series of osmium(VI) nitrido complexes supported by quinolinolato ligands have been prepared and they exhibit promising in vitro anti-cancer activities. These results establish that Os(VI)≡N is a potentially versatile and promising platform for the design of a variety of high-valent anti-cancer drugs.

  17. Electrical wiring of live, metabolically enhanced Bacillus subtilis cells with flexible osmium-redox polymers.

    PubMed

    Coman, Vasile; Gustavsson, Tobias; Finkelsteinas, Arnonas; von Wachenfeldt, Claes; Hägerhäll, Cecilia; Gorton, Lo

    2009-11-11

    The present study explores genetic engineering of the respiratory chain and the application of two different flexible osmium redox polymers to achieve efficient electric communication between the gram-positive organism Bacillus subtilis and an electrode. Poly(1-vinylimidazole)(12)-[Os-(4,4'-dimethyl-2,2'-bipyridyl)(2)Cl(2)](+/2+) (osmium redox polymer I) and poly(vinylpyridine)-[Os-(N,N'-methylated-2,2'-biimidazole)(3)](2+/3+) (osmium redox polymer II) were investigated for efficient electrical "wiring" of viable gram-positive bacterial cells to electrodes. Using a B. subtilis strain that overproduces succinate/quinone oxidoreductase (respiratory complex II), we were able to improve the current response several fold using succinate as substrate, in both batch and flow analysis modes, and using gold and graphite electrodes. The efficiency of the osmium redox polymer, working as electron transfer mediator between the cells and the electrode, was compared with that of a soluble mediator (hexacyanoferrate). The results demonstrated that mediators did not have to pass the cytosolic membrane to bring about an efficient electronic communication between bacterial cells with a thick cell wall and electrodes.

  18. Osmium-catalyzed vicinal oxyamination of alkenes by N-(4-toluenesulfonyloxy)carbamates.

    PubMed

    Masruri; Willis, Anthony C; McLeod, Malcolm D

    2012-10-05

    N-(4-toluenesulfonyloxy)carbamates based on a range of common amine protecting groups serve as preformed nitrogen sources in the intermolecular osmium-catalyzed oxyamination reaction of a variety of mono-, di-, and trisubstituted alkenes. The reactions occur with low catalyst loadings and good yields and afford high regioselectivity for unsymmetrically substituted alkenes.

  19. Anthropogenic osmium in rain and snow reveals global-scale atmospheric contamination.

    PubMed

    Chen, Cynthia; Sedwick, Peter N; Sharma, Mukul

    2009-05-12

    Osmium is one of the rarer elements in seawater, with typical concentration of approximately 10 x 10(-15) g g(-1) (5.3 x 10(-14) mol kg(-1)). The osmium isotope composition ((187)Os/(188)Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (approximately 1.3) and mantle/cosmic dust (approximately 0.13). Here, we show that the (187)Os/(188)Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (approximately 0.2) that are processed to extract platinum and other metals to be used primarily in automobile catalytic converters. Present-day surface seawater has a lower (187)Os/(188)Os ratio (approximately 0.95) than deep waters, suggesting that human activities have altered the isotope composition of the world's oceans and impacted the global geochemical cycle of osmium. The contamination of the surface ocean is particularly remarkable given that osmium has few industrial uses. The pollution may increase with growing demand for platinum-based catalysts.

  20. Anthropogenic osmium in rain and snow reveals global-scale atmospheric contamination

    PubMed Central

    Chen, Cynthia; Sedwick, Peter N.; Sharma, Mukul

    2009-01-01

    Osmium is one of the rarer elements in seawater, with typical concentration of ≈10 × 10−15 g g−1 (5.3 × 10−14 mol kg−1). The osmium isotope composition (187Os/188Os ratio) of deep oceans is 1.05, reflecting a balance between inputs from continental crust (≈1.3) and mantle/cosmic dust (≈0.13). Here, we show that the 187Os/188Os ratios measured in rain and snow collected around the world range from 0.16 to 0.48, much lower than expected (>1), but similar to the isotope composition of ores (≈0.2) that are processed to extract platinum and other metals to be used primarily in automobile catalytic converters. Present-day surface seawater has a lower 187Os/188Os ratio (≈0.95) than deep waters, suggesting that human activities have altered the isotope composition of the world's oceans and impacted the global geochemical cycle of osmium. The contamination of the surface ocean is particularly remarkable given that osmium has few industrial uses. The pollution may increase with growing demand for platinum-based catalysts. PMID:19416862

  1. Structure of the K{sup {pi}} = 4{sup +} bands in {sup 186,188}Os

    SciTech Connect

    Phillips, A. A.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Schumaker, M. A.; Svensson, C. E.; Wong, J.; Bettermann, L.; Braun, N.; Burke, D. G.; Faestermann, T.; Kruecken, R.; Wirth, H.-F.; Hertenberger, R.

    2009-01-28

    The structures of {sub 3}{sup +} states in Os have been debated over several decades. Based on measured B(E2) values they were interpreted in {sup 186-192}Os as K{sup {pi}} = 4{sup +} two-phonon vibrations, whereas inelastic scattering, and (t,{alpha}) work imply a hexadecapole phonon description. To clarify the nature of these K{sup {pi}} = 4{sup +} bands in {sup 186,188}Os, we performed a ({sup 3}He,d) reaction on {sup 185,187}Re targets using 30 MeV {sup 3}He beams and a Q3D spectrograph. Absolute cross sections were obtained for excited states up to 3 MeV at 9 angles from 5 deg. to 50 deg. Results indicate a significant (5/2){sup +}[402]{sub {pi}}+(3/2){sup +}[402]{sub {pi}} component in agreement with quasiparticle phonon model predictions for a single hexadecapole phonon structure.

  2. Dinuclear osmium(II) probes for high-resolution visualisation of cellular DNA structure using electron microscopy.

    PubMed

    Wragg, Ashley; Gill, Martin R; Hill, Christopher J; Su, Xiaodi; Meijer, Anthony J H M; Smythe, Carl; Thomas, Jim A

    2014-12-04

    Two dinuclear osmium polypyridyl complexes function as convenient, easy to handle TEM contrast agents and facilitate the high-resolution visualisation of intracellular structure, particularly sub-nuclear detail.

  3. On line vapor generation of osmium based on solution cathode glow discharge for the determination by ICP-OES.

    PubMed

    Zhu, Zhenli; Huang, Chunying; He, Qian; Xiao, Qing; Liu, Zhifu; Zhang, Suicheng; Hu, Shenghong

    2013-03-15

    A novel plasma induced vapor generation method is proposed to determine osmium in solutions. Without any chemical oxidizing agents, osmium ion can be readily converted to volatile osmium tetraoxide vapor in the solution cathode glow discharge (SCGD) system. The generated osmium vapor is then transported to inductively coupled plasma for determination by optical emission spectrometry. The influences of background electrolyte, carrier gas flow rate, sample flow rate, ICP power and discharge current were investigated. The analytical performances of this proposed technique were evaluated under optimized conditions. The detection limit of Os was calculated to be 0.51 ng mL(-1). The reproducibility, expressed as the relative standard deviation (n=11) of a 2.0 μg mL(-1) standard solution, was 1.9%. This SCGD induced vapor generation is sensitive and simple, oxidation reagents free, providing an alternative analytical method for measuring Os in geological or environmental water samples.

  4. An Entry to Stable Mixed Phosphine-Osmium-NHC Polyhydrides.

    PubMed

    Buil, María L; Cardo, Juan J F; Esteruelas, Miguel A; Fernández, Israel; Oñate, Enrique

    2016-05-16

    An entry to mixed phosphine-osmium-NHC polyhydride complexes is described, starting from the five-coordinate hydrido-alkylidyne compounds [OsHCl(≡CPh)(IPr)(PR3)]OTf (IPr = 1,3-bis(2,6-disopropylphenyl)imidazolylidene; OTf = CF3SO3; PR3 = P(i)Pr3 (1), PPh3 (2)). The experimental procedure involves the borylation of the Os-C triple bond of 1 and 2 with NaBH4 and the subsequent alcoholysis of the borylation products OsH2Cl(η(2)-H-BCH2Ph)(IPr)(PR3) (PR3 = P(i)Pr3 (3), PPh3 (4)) or OsH2(η(2):η(2):H2BCH2Ph)(IPr)(P(i)Pr3) (5). Stirring of 3 in 2-propanol affords the five coordinate chloride-trihydride OsH3Cl(IPr)(P(i)Pr3)2 (6), which reacts with NaBH4 to give OsH3(κ(2)-H2BH2)(IPr)(P(i)Pr3) (7). This trihydride-tetrahydrideborate derivative and its PPh3 counterpart OsH3(κ(2)-H2BH2)(IPr)(PPh3) (8) can be also obtained in a one-pot procedure, starting from 1 and 2 and using methanol at -60 °C instead of 2-propanol as alcoholysis agent. The bonding situation in 7 and 8, analyzed by DFT calculations using AIM and NBO methods, resembles that found in B2H6 and contrasts with the bonding situation in the bis-σ-borane derivative 5. Stirring of 7 and 8 in 2-propanol leads to the corresponding d(2)-hexahydride derivatives OsH6(IPr)(PR3) (PR3 = P(i)Pr3 (9), PPh3 (10)), which reduce the C≡N triple bond of benzonitrile and promote the subsequent chelate-assisted ortho-CH bond activation of the resulting phenylmethanimine, to form the trihydride compounds OsH3{κ(2)-N,C-(NH═CH-C6H4)}(IPr)(PR3)2 (PR3 = P(i)Pr3 (11), PPh3 (12)), containing a stabilized orthometalated aldimine.

  5. Level Structure Above the T1/2 = 2 . 0 ×105 yr Isomer in 186Re

    NASA Astrophysics Data System (ADS)

    Matters, D. A.; McClory, J. W.; Kondev, F. G.; Carpenter, M. P.; Carroll, J. J.; Chiara, C. J.; Lane, G. J.; Kibédi, T.; Ideguchi, E.; Fang, Y.; Watanabe, H.; E435 Cagra Collaboration

    2016-03-01

    The level structure above the Kπ = (8+) , 149-keV isomer in 186Re is largely undeveloped. The isomer could play a role in the s-process nucleosynthesis of 187Os and 187Re and affect the accuracy of the Re-Os cosmochronometer. An experiment was conducted at the Research Center for Nuclear Physics (RCNP) at Osaka University, Japan, using the Clover Array Gamma-ray spectrometer at RCNP/RIBF for Advanced research (CAGRA) to measure γ-ray coincidences from (d , 2 n) reactions on an enriched 186W target. The γ - γ coincidence data obtained from the CAGRA array were analyzed along with data from a similar experiment performed in 2006 at the Australian National University. A preliminary analysis of the data reveals several new levels and transitions feeding the 186mRe isomer.

  6. Evidence for homogeneous distribution of osmium in the protosolar nebula

    NASA Astrophysics Data System (ADS)

    Walker, Richard J.

    2012-10-01

    Separate s-, r-, and possibly p-process enriched and depleted components have been shown to host Os in low metamorphic grade chondrites, although no measureable Os isotopic anomalies have yet been discovered for bulk chondrites. Here, iron meteorites from groups IAB, IIAB, IIIAB, IVA and IVB, as well as the main group pallasites are examined. Many of these meteorites show well-resolved anomalies in ɛ190Os, ɛ189Os and ɛ186Osi. The anomalies, however, differ from those observed in chemically extracted components from chondrites, and are interpreted to reflect long-term exposure of the meteorites to cosmic rays, rather than nucleosynthetic effects. A neutron capture model is presented that can well account for observed isotopic variations in 190Os and 189Os. The same model predicts greater enrichment in 186Osi than is observed for at least one iron, suggesting as yet unaccounted for effects, or failings of the model. Despite the variable anomalies resulting from cosmic ray exposure, each of the major meteorite groups examined contains at one member with normal Os isotopic compositions that are unresolved from chondritic compositions. This indicates that some domains within these meteorites were little affected by cosmic rays. These domains are excellent candidates for application of the 182Hf-182W system for dating metal-silicate segregation on their parent bodies. The normal Os also implies that Os was homogeneously distributed throughout the protosolar nebula on the scale of planetesimal accretion, within the current level of analytical resolution. The homogeneity in Os contrasts with isotopic heterogeneity present for other siderophile elements, including Mo, Ru and W. The contrast in the scale of anomalies may reflect a late stage-injection of s- and p- process rich material into the coalescing nebula. Alternately, nebular thermal processing and destruction of some presolar host phases of Mo, Ru and W may also be responsible.

  7. Formation, tidal evolution, and habitability of the Kepler-186 system

    SciTech Connect

    Bolmont, Emeline; Raymond, Sean N.; Selsis, Franck; Hersant, Franck; Von Paris, Philip; Quintana, Elisa V.; Barclay, Thomas

    2014-09-20

    The Kepler-186 system consists of five planets orbiting an early M dwarf. The planets have physical radii of 1.0-1.50 R {sub ⊕} and orbital periods of 4-130 days. The 1.1 R {sub ⊕} Kepler-186f with a period of 130 days is of particular interest. Its insolation of roughly 0.32 S {sub ⊕} places it within the surface liquid water habitable zone (HZ). We present a multifaceted study of the Kepler-186 system, using two sets of parameters which are consistent with the data and also self-consistent. First, we show that the distribution of planet masses can be roughly reproduced if the planets were accreted from a high surface density disk presumably sculpted by an earlier phase of migration. However, our simulations predict the existence of one to two undetected planets between planets e and f. Next, we present a dynamical analysis of the system including the effect of tides. The timescale for tidal evolution is short enough that the four inner planets must have small obliquities and near-synchronous rotation rates. The tidal evolution of Kepler-186f is slow enough that its current spin state depends on a combination of its initial spin state, its dissipation rate, and the stellar age. Finally, we study the habitability of Kepler-186f with a one-dimensional climate model. The planet's surface temperature can be raised above 273 K with 0.5-5 bars of CO{sub 2}, depending on the amount of N{sub 2} present. Kepler-186f represents a case study of an Earth-sized planet in the cooler regions of the HZ of a cool star.

  8. 50 CFR 622.186 - Landing fish intact.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...-Grouper Fishery of the South Atlantic Region § 622.186 Landing fish intact. (a) South Atlantic snapper-grouper in or from the South Atlantic EEZ must be maintained with head and fins intact, except as..., snapper-grouper lawfully harvested in Bahamian waters are exempt from the requirement that they...

  9. 50 CFR 622.186 - Landing fish intact.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...-Grouper Fishery of the South Atlantic Region § 622.186 Landing fish intact. (a) South Atlantic snapper-grouper in or from the South Atlantic EEZ must be maintained with head and fins intact, except as..., snapper-grouper lawfully harvested in Bahamian waters are exempt from the requirement that they...

  10. 27 CFR 25.186 - Record of beer transferred.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY LIQUORS BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred...

  11. 27 CFR 25.186 - Record of beer transferred.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2013-04-01 2013-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY ALCOHOL BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred...

  12. 27 CFR 25.186 - Record of beer transferred.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2011-04-01 2011-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY LIQUORS BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred...

  13. 27 CFR 25.186 - Record of beer transferred.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2014-04-01 2014-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY ALCOHOL BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred...

  14. 27 CFR 555.186 - Seizure or forfeiture.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... EXPLOSIVES, DEPARTMENT OF JUSTICE EXPLOSIVES COMMERCE IN EXPLOSIVES Marking of Plastic Explosives § 555.186 Seizure or forfeiture. Any plastic explosive that does not contain a detection agent in violation of 18 U... of this chapter for regulations on summary destruction of plastic explosives that do not contain...

  15. 18.6-year Earth tide regulates geyser activity.

    PubMed

    Rinehart, J S

    1972-07-28

    Over 40 years of records from Yellowstone National Park, Wyoming, show that the 18.6-year tidal component strongly regulates the frequencies of eruption of Grand and Steamboat geysers. The frequency of Grand Geyser increases with increasing tidal force and that of Steamboat Geyser decreases, which suggests that tidal dilatation is one factor affecting heat flow to a geyser.

  16. 5 CFR 550.186 - Relationship to other payments.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... ADMINISTRATION (GENERAL) Premium Pay Law Enforcement Availability Pay § 550.186 Relationship to other payments... does not affect an investigator's entitlement to other types of premium pay (including overtime pay... receiving availability pay may not be paid any other premium pay based on unscheduled duty hours....

  17. 27 CFR 25.186 - Record of beer transferred.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Record of beer transferred..., DEPARTMENT OF THE TREASURY LIQUORS BEER Removals Without Payment of Tax Transfer to Another Brewery of Same Ownership § 25.186 Record of beer transferred. (a) Preparation of invoice. When beer is transferred...

  18. 186. Photocopy of drawing (1975 demolition drawing by the Ralph ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    186. Photocopy of drawing (1975 demolition drawing by the Ralph M. Parsons Company) DEMOLITION AND REMOVAL PLANS FOR THE MST; NORTH, SOUTH, AND EAST, TOWER ELEVATIONS, SHEET D-3 - Vandenberg Air Force Base, Space Launch Complex 3, Launch Pad 3 East, Napa & Alden Roads, Lompoc, Santa Barbara County, CA

  19. First-principles study of structural and thermodynamic properties of osmium

    NASA Astrophysics Data System (ADS)

    Liu, Ke; He, Duan-Wei; Zhou, Xiao-Lin; Chen, Hai-Hua

    2011-08-01

    We employ the first-principles plane wave pseudopotential density functional theory method to calculate the equilibrium lattice parameters of osmium and the thermodynamic properties of hcp structure osmium. The obtained lattice parameters are in good agreement with the experimental data investigated up to 58.2 GPa using radial X-ray diffraction (RXRD) together with lattice strain theory in a diamond-anvil cell and the available theoretical data of others. Through the quasi-harmonic Debye model, the dependencies of the normalized lattice parameters a/ a0 and c/ c0 on pressure P, the normalized primitive volume V/V0 on pressure P, the Debye temperature ΘD and the heat capacity CV on pressure P and temperature T, as well as the variation of the thermal expansion α with temperature and pressure are obtained successfully.

  20. Use of an osmium complex as a universal luminescent probe for enzymatic reactions.

    PubMed

    Virel, Ana; Sanchez-Lopez, Jose; Saa, Laura; García, Ana Carla; Pavlov, Valeri

    2009-06-15

    The water-soluble bis(bipyridine)chloro(4-picolinic acid) osmium complex, [Os(III)(bpy)2Cl(PyCOOH)]2+ (bpy=2,2'-bipyridine, Py=pyridine), is fluorescent in aqueous solution, whereas the reduced form of the complex, [Os(II)(bpy)2Cl(PyCOOH)]+, shows no significant fluorescence under the same conditions. Such reversible redox control of the fluorescence of the complex can be easily adapted to follow any enzymatic reaction to yield oxidising or reducing products that are capable of interacting with [Os(III)(bpy)2Cl(PyCOOH)]2+ or [Os(II)(bpy)2Cl(PyCOOH)]+. Based on the redox reaction between products of biocatalytic reactions and the osmium complex, we have designed a simple bioanalytical assay for the detection of nerve gases, alpha-ketoglutarate, hydrogen peroxide and glucose.

  1. Electrochemical communication between microbial cells and electrodes via osmium redox systems.

    PubMed

    Hasan, Kamrul; Patil, Sunil A; Leech, Dónal; Hägerhäll, Cecilia; Gorton, Lo

    2012-12-01

    Electrochemical communication between micro-organisms and electrodes is the integral and fundamental part of BESs (bioelectrochemical systems). The immobilization of bacterial cells on the electrode and ensuring efficient electron transfer to the electrode via a mediator are decisive features of mediated electrochemical biosensors. Notably, mediator-based systems are essential to extract electrons from the non-exoelectrogens, a major group of microbes in Nature. The advantage of using polymeric mediators over diffusible mediators led to the design of osmium redox polymers. Their successful use in enzyme-based biosensors and BFCs (biofuel cells) paved the way for exploring their use in microbial BESs. The present mini-review focuses on osmium-bound redox systems used to date in microbial BESs and their role in shuttling electrons from viable microbial cells to electrodes.

  2. Rhenium-osmium concentration and isotope systematics in group IIAB iron meteorites

    USGS Publications Warehouse

    Morgan, J.W.; Horan, M.F.; Walker, R.J.; Grossman, J.N.

    1995-01-01

    Rhenium and osmium abundances, and osmium isotopic compositions were measured by negative thermal ionization mass spectrometry in thirty samples, including replicates, of five IIA and eight IIB iron meteorites. Log plots of Os vs. Re abundances for IIA and IIB irons describe straight lines that approximately converge on Lombard, which has the lowest Re and Os abundances and highest 187Re/188Os measured in a IIA iron to date. The linear IIA trend may be exactly reproduced by fractional crystallization, but is not well fitted using variable partition coefficients. The IIB iron trend, however, cannot be entirely explained by simple fractional crystallization. One explanation is that small amounts of Re and Os were added to the asteroid core during the final stages of crystallization. Another possibility is that diffusional enrichment of Os may have occurred in samples most depleted in Re and Os. -from Authors

  3. Osmium polypyridyl complexes and their applications to dye-sensitized solar cells.

    PubMed

    Swetha, T; Reddy, K Raveendranath; Singh, Surya Prakash

    2015-04-01

    Dye-sensitized solar cells (DSSCs) have received much attention in recent years owing to their efficient conversion of sunlight to electricity. DSSCs became successful alternatives to silicon photovoltaic devices by virtue of their low fabrication costs and easy preparation methods. In DSSCs the dye plays the key role. This review summarizes the applications of osmium sensitizers in DSSCs. We also briefly discussed their synthesis and the effect of various electrolyte systems on device efficiencies.

  4. MCDHF calculations of isotope shifts of even-parity fine-structure levels in neutral osmium

    NASA Astrophysics Data System (ADS)

    Palmeri, P.; Quinet, P.; Bouazza, S.

    2016-12-01

    Ab initio multiconfiguration Dirac-Hartree-Fock (MCDHF) calculations have been carried out in order to determine the isotope shifts of all the fine-structure levels belonging to the even-parity configurations (5d+6s)8 in neutral osmium, Os I. The theoretical predictions have been compared to laser spectroscopy measurements available in the literature showing a good agreement between theory and experiment.

  5. DNA photocleavage by an osmium(II) complex in the PDT window.

    PubMed

    Sun, Yujie; Joyce, Lauren E; Dickson, Nicole M; Turro, Claudia

    2010-09-28

    The extended pi-delocalization of dppn (benzo[i]dipyrido[3,2-a:2,3-c]phenazine) results in a (3)pipi* state as the lowest triplet excited state in [Os(bpy)(2)(dppn)](2+) (bpy = 2,2'-bipyridine), which generates a (1)O(2) quantum yield of 0.42. Together with its (3)MLCT absorption, this new osmium complex shows efficient DNA cleavage under irradiation of lambda(irr) > or = 645 nm.

  6. Isotopic signature and impact of car catalysts on the anthropogenic osmium budget.

    PubMed

    Poirier, André; Gariépy, Clement

    2005-06-15

    Higher osmium concentrations and lower 187Os/188Os ratios in sediments from urban areas have been linked to anthropogenic osmium sources. Automobile catalytic converters that use platinum group metals (PGM) are a potential source for this Os pollution. We present the first direct Os concentrations and isotopic measurements of catalytic converters for major automobile brands to test the assumption that car catalysts release Os with a distinct signature in the environment. The analysis of four new catalytic converters yields similar low 187Os/188Os ratios (0.1-0.2), suggesting a similar source for the PGM. The Os concentrations measured are in the ppt range (6-228 ppt). From our results, the osmium contribution of the car catalysts to the environment through attrition (wearing and grinding down of the catalyst by friction) is predicted to be low, <0.2 pg Os/m2/year in highly urbanized environment. We show that Os loss from catalysts as volatile OsO4 is important at car catalyst operating temperatures. Moreover, we estimate that car catalysts may be responsible for up to approximately 120 pg Os/m2 deposited per year in urban areas and that part of it may be exported to sedimentary sinks. Car catalytic converters are thus an important anthropogenic osmium source in densely populated areas. The NIST car catalyst standard (SRM-2557, made from recycled used catalysts) yields higher concentrations (up to 721 ppt Os) and a more radiogenic isotopic composition (approximately 0.38), perhaps indicative of Os contamination during its preparation.

  7. Ligand-free osmium clusters supported on MgO. A density functional study

    SciTech Connect

    Goellner, J.F.; Neyman, K.M.; Mayer, M.; Noertemann, F.; Gates, B.C.; Roesch, N.

    2000-03-21

    The interactions of Os{sub 4}, Os{sub 5}, and Os{sub 5}C clusters with various sites of a MgO(001) support were investigated theoretically with the aid of a scalar-relativistic density functional cluster model method. Adsorption geometries of C{sub 4{upsilon}} clusters centered above a magnesium cation and the Os atoms oriented either to the nearest surface oxygen anions (A) or between them (B) were considered. The influence of surface V{sub s} and V{sub s}{sup 2{minus}} defects on the adsorption of the clusters was also investigated. The calculated base Os-Os distances in supported Os{sub 5} and Os{sub 5}C square-pyramidal clusters are at most 0.1 {angstrom} longer (2.5--2.6{angstrom}) than the values calculated for the corresponding free osmium cluster but about 0.4{angstrom} (or more) shorter than the values determined by EXAFS spectroscopy for MgO-powder-supported clusters formed by decarbonylation of [Os{sub 5}C(CO){sub 14}]{sup 2{minus}} and shown to retains the Os{sub 5}C frame. The experimental Os-Os distances characterizing the supported clusters are close to the experimental and calculated bond lengths for coordinatively saturated osmium carbonyl clusters; the result favors the suggestion that the supported clusters characterized by EXAFS spectroscopy were not entirely ligand-free. The models reported here are inferred to be too simplified to capture all the pertinent structural details of MgO-powder-supported osmium clusters, but they are sufficient to indicate a significant role of defect sites in the adsorption of supported osmium clusters and, the authors infer, other transition metal clusters.

  8. Osmium isotope and highly siderophile element systematics of the lunar crust

    USGS Publications Warehouse

    Day, J.M.D.; Walker, R.J.; James, O.B.; Puchtel, I.S.

    2010-01-01

    Coupled 187Os/188Os and highly siderophile element (HSE: Os, Ir, Ru, Pt, Pd, and Re) abundance data are reported for pristine lunar crustal rocks 60025, 62255, 65315 (ferroan anorthosites, FAN) and 76535, 78235, 77215 and a norite clast in 15455 (magnesian-suite rocks, MGS). Osmium isotopes permit more refined discrimination than previously possible of samples that have been contaminated by meteoritic additions and the new results show that some rocks, previously identified as pristine, contain meteorite-derived HSE. Low HSE abundances in FAN and MGS rocks are consistent with derivation from a strongly HSE-depleted lunar mantle. At the time of formation, the lunar floatation crust, represented by FAN, had 1.4 ?? 0.3 pg g- 1 Os, 1.5 ?? 0.6 pg g- 1 Ir, 6.8 ?? 2.7 pg g- 1 Ru, 16 ?? 15 pg g- 1 Pt, 33 ?? 30 pg g- 1 Pd and 0.29 ?? 0.10 pg g- 1 Re (??? 0.00002 ?? CI) and Re/Os ratios that were modestly elevated (187Re/188Os = 0.6 to 1.7) relative to CI chondrites. MGS samples are, on average, characterised by more elevated HSE abundances (??? 0.00007 ?? CI) compared with FAN. This either reflects contrasting mantle-source HSE characteristics of FAN and MGS rocks, or different mantle-crust HSE fractionation behaviour during production of these lithologies. Previous studies of lunar impact-melt rocks have identified possible elevated Ru and Pd in lunar crustal target rocks. The new results provide no supporting evidence for such enrichments. If maximum estimates for HSE in the lunar mantle are compared with FAN and MGS averages, crust-mantle concentration ratios (D-values) must be ??? 0.3. Such D-values are broadly similar to those estimated for partitioning between the terrestrial crust and upper mantle, with the notable exception of Re. Given the presumably completely different mode of origin for the primary lunar floatation crust and tertiary terrestrial continental crust, the potential similarities in crust-mantle HSE partitioning for the Earth and Moon are somewhat

  9. Osmium(II)--versus ruthenium(II)--arene carbohydrate-based anticancer compounds: similarities and differences.

    PubMed

    Hanif, Muhammad; Nazarov, Alexey A; Hartinger, Christian G; Kandioller, Wolfgang; Jakupec, Michael A; Arion, Vladimir B; Dyson, Paul J; Keppler, Bernhard K

    2010-08-21

    The synthesis and in vitro anticancer activity of Os(II)-arene complexes with carbohydrate-derived phosphite co-ligands are reported. The compounds were characterized by standard methods and the molecular structure of dichlorido(eta(6)-p-cymene)(3,5,6-bicyclophosphite-1,2-O-isopropylidene-alpha-D-glucofuranoside)osmium(II) was determined by X-ray diffraction analysis. Complexes with chlorido leaving groups undergo hydrolysis by consecutive formation of aqua compounds, followed by cleavage of a P-O bond of sugar phosphite ligands, as demonstrated by NMR studies. These observations are similar to those of analogous Ru(II)-arene complexes; however the rate of hydrolysis is very slow for osmium compounds. The complexes with oxalato leaving groups resist hydrolysis; no hydrolytic species were detected by (31)P{(1)H} NMR spectroscopy over several days. Within this series of Os compounds, in vitro anticancer activity is highest for the most lipophilic chlorido complex dichlorido(eta(6)-p-cymene)(3,5,6-bicyclophosphite-1,2-O-cyclohexylidene-alpha-D-glucofuranoside)osmium(II).

  10. Osmium and neodymium isotopic constraints on the temporal and spatial evolution of Siberian flood basalt sources

    USGS Publications Warehouse

    Horan, M.F.; Walker, R.J.; Fedorenko, V.A.; Czamanske, G.K.

    1995-01-01

    Picrites from the Gudchikhinsky suite, the oldest rocks examined, have ??Os of +5.3 to +6.1 and ??Nd of +3.7 to +4.0. The osmium and neodymium isotopic compositions of these rocks are similar to some modern ocean-island basalts (OIB), consistent with their derivation from an mantle plume. Picrites from the stratigraphically higher Tuklonsky suite have similar ??Os of +3.4 to +6.5, but ??Nd of -0.9 to -2.6. The similar ??Os, but lower ??Nd , suggest that some magmas from the same OIB-type, mantle source were contaminated by lithospheric components. A differentiated ankaramite flow, associated with the top of the stratigraphically higher Morongovsky suite, has ??Os of +9.8 to +10.2 and ??Nd of +1.3 to +1.4. The higher ??Os may indicate that the plume source was heterogeneous with respect to osmium isotopic composition, consistent with osmium isotopic measurements in rocks from other plume sources. Mg-rich, alkaline rocks (meymechites) from the Guli area that erupted much nearer the end of the flood-basalt event have ??Os of -1.2 to -2.6 and ??Nd of +3.7 to +4.9. These rocks were probably produced by low degrees of partial melting of mantle after the main stages of flood-basalt production. -from Authors

  11. Osmium-isotope ratios of platinum-group minerals associated with ultramafic intrusions: Os-isotopic evolution of the oceanic mantle

    NASA Astrophysics Data System (ADS)

    Hattori, Keiko; Hart, Stanley R.

    1991-12-01

    Osmium-isotope ratios were determined by an ion microprobe on the individual platinum-group minerals (PGM) from placers, which are associated with ultramafic intrusions of late Precambrian to Tertiary age. Unlike Os-isotope ratios in large layered mafic intrusions, these 187Os/ 186Os ratios are low, and within a narrow range from 0.99 to 1.12, which is attributed to the occurrences of the intrusions. There was no opportunity to incorporate old crustal Os because of the small sizes of the intrusions and the mode of emplacement into the upper crustal level. In addition, the interaction with the host volcanic rocks of similar age, if any, would not have seriously affected the 187Os/ 86Os ratios of the peridotites. While different phases of PGM in one grain have similar 187Os/ 186Os ratios, there is a significant variation in a given district. The variation is attributed to a long-term heterogeneity in Re/Os ratios of the oceanic upper mantle. The lowest value in each area is lower than the value expected from the evolution of bulk Earth composition. The lowering may be due to primordially low Re/Os ratios in the mantle or preferential removal of Re by partial melting to form the continental crust. The former model is rejected because most chondrites have higher Re/Os ratios than type C1 and the core-mantle separation would not have lowered Re/Os ratios. The low 187Os/ 186Os ratios are, therefore attributed to the extraction of continental crust by preferential removal of Re from the mantle through partial melting. The model is consistent with the depleted nature of oceanic peridotites (positive ɛ Nd, negative ɛ Sr, and low Re/Os ratios). Calculations of 187Os/ 186Os ratios of the mantle residue suggest that the observed data are in accordance with a model involving the extraction of ˜ 2% melt by fractional fusion from the mantle of C1 chondritic composition at ˜ 2.0 Ga. If the bulk Earth has higher Re/Os ratios, as proposed by Martin [1], then the observed data

  12. Coliphage 186 genetic switch: a single molecule study

    NASA Astrophysics Data System (ADS)

    Wang, Haowei; Dodd, Ian B.; Shearwin, Keith; Dunlap, David; Finzi, Laura

    2009-11-01

    It is increasingly clear that in most cases genes are regulated by wrapping or looping of DNA on large, cooperatively assembled protein complexes. In most eukaryotic organisms, 150 bp of DNA are wrapped twice around histone octamers (nucleosomes). Furthermore, interaction between proteins bound at distant sites on the DNA may cause looping out of the intervening DNA with regulatory significance. The mechanism by which these DNA- protein nanostructures are formed is not clear. It is tantalizing how little information is available about the energetics, kinetics and equilibrium between DNA wrapping and looping given the crucial role they play on gene regulation and DNA physiology. The interaction between the bacteriophage repressor 186CI and its DNA is an ideal model system to study DNA wrapping and looping and to reveal fundamental principles of long-range interactions and regulation by nucleoprotein complexes. Here we report on AFM work aimed at elucidating the 186CI-DNA interaction.

  13. Upregulation of kazrin F by miR-186 suppresses apoptosis but promotes epithelial-mesenchymal transition to contribute to malignancy in human cervical cancer cells

    PubMed Central

    Liu, Chang; Wang, Jinghua; Hu, Yang; Xie, Hong; Liu, Min; Tang, Hua

    2017-01-01

    Objective Previous studies have identified that kazrin is a constituent of desmosome and influences intercellular adhesion, growing development and morphology. We previously cloned another new isoform, kazrin F and found that it has anti-apoptotic effects on human glioma cell line. To further explore whether kazrin F is involved in tumorigenesis, we investigated its expression and role in cervical cancer (CC) cells. Methods The role of kazrin F and miR-186 in CC was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, colony formation, transwell, and apoptosis assays. Using enhanced green fluorescent protein (EGFP) reporter assays, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and western blot analysis, we identified kazrin F post-transcriptional regulation by miR-186. Results We demonstrate that kazrin F is highly expressed in CC tissues compared with the adjacent noncancerous tissues and promotes cell proliferation, colony formation, migration and invasion in HeLa and C33A cells by suppressing apoptosis and facilitating epithelial-to-mesenchymal transition (EMT). Furthermore, miR-186 was confirmed as a regulator of kazrin F dysregulation. An EGFP reporter assay proved that miR-186 directly targets the 3’-untranslated region (3’UTR) of kazrin F and downregulates its expression, and miR-186 expression showed an inverse correlation with kazrin F levels in CC tissues. In addition, overexpression of miR-186 suppressed the malignant behaviors of CC cells. The ectopic expression of kazrin F rescued the inhibitory effects of miR-186. Conclusions Our findings indicate that the upregulation of kazrin F due to downregulated miR-186 levels contributes to malignancy, and highlight the significance of kazrin F in CC tumorigenesis. PMID:28373753

  14. A protein-truncating R179X variant in RNF186 confers protection against ulcerative colitis

    PubMed Central

    Rivas, Manuel A.; Graham, Daniel; Sulem, Patrick; Stevens, Christine; Desch, A. Nicole; Goyette, Philippe; Gudbjartsson, Daniel; Jonsdottir, Ingileif; Thorsteinsdottir, Unnur; Degenhardt, Frauke; Mucha, Sören; Kurki, Mitja I.; Li, Dalin; D'Amato, Mauro; Annese, Vito; Vermeire, Severine; Weersma, Rinse K.; Halfvarson, Jonas; Paavola-Sakki, Paulina; Lappalainen, Maarit; Lek, Monkol; Cummings, Beryl; Tukiainen, Taru; Haritunians, Talin; Halme, Leena; Koskinen, Lotta L. E.; Ananthakrishnan, Ashwin N.; Luo, Yang; Heap, Graham A.; Visschedijk, Marijn C.; Barrett, J; de Lange, K; Edwards, C; Hart, A; Hawkey, C; Jostins, L; Kennedy, N; Lamb, C; Lee, J; Lees, C; Mansfield, J; Mathew, C; Mowatt, C; Newman, W; Nimmo, E; Parkes, M; Pollard, M; Prescott, N; Randall, J; Rice, D; Satsangi, J; Simmons, A; Tremelling, M; Uhlig, H; Wilson, D; Abraham, C; Achkar, J.P; Bitton, A; Boucher, G; Croitoru, K; Fleshner, P; Glas, J; Kugathasan, S; Limbergen, J.V; Milgrom, R; Proctor, D; Regueiro, M; Schumm, P.L; Sharma, Y; Stempak, J.M; Targan, S.R; Wang, M.H; MacArthur, Daniel G.; Neale, Benjamin M.; Ahmad, Tariq; Anderson, Carl A.; Brant, Steven R.; Duerr, Richard H.; Silverberg, Mark S.; Cho, Judy H; Palotie, Aarno; Saavalainen, Päivi; Kontula, Kimmo; Färkkilä, Martti; McGovern, Dermot P. B.; Franke, Andre; Stefansson, Kari; Rioux, John D.; Xavier, Ramnik J.; Daly, Mark J.; Barrett, J.; de Lane, K.; Edwards, C.; Hart, A.; Hawkey, C.; Jostins, L.; Kennedy, N.; Lamb, C.; Lee, J.; Lees, C.; Mansfield, J.; Mathew, C.; Mowatt, C.; Newman, B.; Nimmo, E.; Parkes, M.; Pollard, M.; Prescott, N.; Randall, J.; Rice, D.; Satsangi, J.; Simmons, A.; Tremelling, M.; Uhlig, H.; Wilson, D.; Abraham, C.; Achkar, J. P.; Bitton, A.; Boucher, G.; Croitoru, K.; Fleshner, P.; Glas, J.; Kugathasan, S.; Limbergen, J. V.; Milgrom, R.; Proctor, D.; Regueiro, M.; Schumm, P. L.; Sharma, Y.; Stempak, J. M.; Targan, S. R.; Wang, M. H.

    2016-01-01

    Protein-truncating variants protective against human disease provide in vivo validation of therapeutic targets. Here we used targeted sequencing to conduct a search for protein-truncating variants conferring protection against inflammatory bowel disease exploiting knowledge of common variants associated with the same disease. Through replication genotyping and imputation we found that a predicted protein-truncating variant (rs36095412, p.R179X, genotyped in 11,148 ulcerative colitis patients and 295,446 controls, MAF=up to 0.78%) in RNF186, a single-exon ring finger E3 ligase with strong colonic expression, protects against ulcerative colitis (overall P=6.89 × 10−7, odds ratio=0.30). We further demonstrate that the truncated protein exhibits reduced expression and altered subcellular localization, suggesting the protective mechanism may reside in the loss of an interaction or function via mislocalization and/or loss of an essential transmembrane domain. PMID:27503255

  15. Short review of high-pressure crystal growth and magnetic and electrical properties of solid-state osmium oxides

    SciTech Connect

    Yamaura, Kazunari

    2016-04-15

    High-pressure crystal growth and synthesis of selected solid-state osmium oxides, many of which are perovskite-related types, are briefly reviewed, and their magnetic and electrical properties are introduced. Crystals of the osmium oxides, including NaOsO{sub 3}, LiOsO{sub 3}, and Na{sub 2}OsO{sub 4}, were successfully grown under high-pressure and high-temperature conditions at 6 GPa in the presence of an appropriate amount of flux in a belt-type apparatus. The unexpected discovery of a magnetic metal–insulator transition in NaOsO{sub 3}, a ferroelectric-like transition in LiOsO{sub 3}, and high-temperature ferrimagnetism driven by a local structural distortion in Ca{sub 2}FeOsO{sub 6} may represent unique features of the osmium oxides. The high-pressure and high-temperature synthesis and crystal growth has played a central role in the development of solid-state osmium oxides and the elucidation of their magnetic and electronic properties toward possible use in multifunctional devices. - Graphical Abstract: Flux-grown crystals of NaOsO{sub 3} under high-pressure and high-temperature conditions in a belt-type apparatus. The crystal shows a magnetically driven metal–insulator transition at a temperature of 410 K. - Highlights: • Short review of high-pressure crystal growth of solid-state osmium oxides. • Wide variety of magnetic properties of solid-state osmium oxides. • Perovskite and related dense structures stabilized at 3–17 GPa.

  16. 16 CFR 18.6 - Plants collected from the wild state.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 16 Commercial Practices 1 2011-01-01 2011-01-01 false Plants collected from the wild state. 18.6 Section 18.6 Commercial Practices FEDERAL TRADE COMMISSION GUIDES AND TRADE PRACTICE RULES GUIDES FOR THE NURSERY INDUSTRY § 18.6 Plants collected from the wild state. It is an unfair or deceptive act or...

  17. 42 CFR 413.186 - Payment exception: Self-dialysis training costs in pediatric facilities.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... pediatric facilities. 413.186 Section 413.186 Public Health CENTERS FOR MEDICARE & MEDICAID SERVICES... NURSING FACILITIES Payment for End-Stage Renal Disease (ESRD) Services and Organ Procurement Costs § 413.186 Payment exception: Self-dialysis training costs in pediatric facilities. (a) Qualification....

  18. 77 FR 21538 - Announcing DRAFT Revisions to Federal Information Processing Standard (FIPS) 186-3, Digital...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-10

    ... algorithm (DSA) to generate and verify digital signatures. Later revisions (FIPS 186-1, FIPS 186-2, and FIPS 186-3, adopted in 1998, 1999 and 2009, respectively) adopted two additional algorithms: The Elliptic Curve Digital Signature Algorithm (ECDSA) and the RSA digital signature algorithm. NIST is...

  19. Osmium-catalyzed tethered aminohydroxylation of glycals: a stereodirected access to 2- and 3-aminosugars.

    PubMed

    Mirabella, Stefania; Cardona, Francesca; Goti, Andrea

    2015-02-06

    The osmium-catalyzed aminohydroxylation of glycals has been achieved with complete regio- and stereocontrol by taking advantage of the Donohoe tethering approach. Glucals and galactals showed complementary reactivity in dependence of the stage at which the reaction was performed, i.e., directly or after double-bond shift consequent to a Ferrier rearrangement (that is, on the 1,2 or 2,3-unsaturated sugar), allowing access to both classes of 2-amino (mannosamine) and 3-amino (talosamine) sugar derivatives, respectively.

  20. Features of the band structure for semiconducting iron, ruthenium, and osmium monosilicides

    SciTech Connect

    Shaposhnikov, V. L. Migas, D. B.; Borisenko, V. E.; Dorozhkin, N. N.

    2009-02-15

    The pseudopotential method has been used to optimize the crystal lattice and calculate the energy band spectra for iron, ruthenium and, osmium monosilicides. It is found that all these compounds are indirect-gap semiconductors with band gaps of 0.17, 0.22, and 0.50 eV (FeSi, RuSi, and OsSi, respectively). A distinctive feature of their band structure is the 'loop of extrema' both in the valence and conduction bands near the center of the cubic Brillouin zone.

  1. Photocurrent generation from thylakoid membranes on osmium-redox-polymer-modified electrodes.

    PubMed

    Hamidi, Hassan; Hasan, Kamrul; Emek, Sinan Cem; Dilgin, Yusuf; Åkerlund, Hans-Erik; Albertsson, Per-Åke; Leech, Dónal; Gorton, Lo

    2015-03-01

    Thylakoid membranes (TMs) are uniquely suited for photosynthesis owing to their distinctive structure and composition. Substantial efforts have been directed towards use of isolated photosynthetic reaction centers (PRCs) for solar energy harvesting, however, few studies investigate the communication between whole TMs and electrode surfaces, due to their complex structure. Here we report on a promising approach to generate photosynthesis-derived bioelectricity upon illumination of TMs wired with an osmium-redox-polymer modified graphite electrode, and generate a photocurrent density of 42.4 μA cm(-2).

  2. Proton-coupled electron transfer and multielectron oxidations in complexes of ruthenium and osmium

    SciTech Connect

    Dovletoglou, A.

    1992-01-01

    This doctoral research concerns the mechanism of proton-coupled electron transfer over an extended pH range. These processes between ruthenium and osmium complexes and hydroquinones have been studied using spectrophotometric methods and cyclic voltammetry. Elucidation of the mechanistic details has been attempted by using isotopic labelling, kinetic analysis, and numerical simulation of complex kinetic schemes. The coordination and redox chemistry of polypyridyl-acetylacetonato and -oxalato complexes of ruthenium and the role of ancillary ligands in defining the properties of Ru[sup IV]O complexes were explored. These studies represent the first attempt to probe possible 2e[sup [minus

  3. Direct radiometric dating of hydrocarbon deposits using rhenium-osmium isotopes.

    PubMed

    Selby, David; Creaser, Robert A

    2005-05-27

    Rhenium-osmium (Re-Os) data from migrated hydrocarbons establish the timing of petroleum emplacement for the giant oil sand deposits of Alberta, Canada, at 112 +/- 5.3 million years ago. This date does not support models that invoke oil generation and migration for these deposits in the Late Cretaceous. Most Re-Os data from a variety of deposits within the giant hydrocarbon system show similar characteristics, supporting the notion of a single source for these hydrocarbons. The Re-Os data disqualify Cretaceous rocks as the primary hydrocarbon source but suggest an origin from older source rocks. This approach should be applicable to dating oil deposits worldwide.

  4. Osmium(II) polypyridyl polyarginine conjugate as a probe for live cell imaging; a comparison of uptake, localization and cytotoxicity with its ruthenium(II) analogue.

    PubMed

    Byrne, Aisling; Dolan, Ciarán; Moriarty, Roisin D; Martin, Aaron; Neugebauer, Ute; Forster, Robert J; Davies, Anthony; Volkov, Yuri; Keyes, Tia E

    2015-08-28

    A first investigation into the application of a luminescent osmium(ii) bipyridine complex to live cell imaging is presented. Osmium(ii) (bis-2,2-bipyridyl)-2(4-carboxylphenyl) imidazo[4,5f][1,10]phenanthroline was prepared and conjugated to octaarginine, a cell penetrating peptide. The photophysics, cell uptake and cytotoxicity of this osmium complex conjugate were performed and compared with its ruthenium analogue. Cell uptake and distribution of both ruthenium and osmium conjugates were very similar with rapid transmembrane transport of the osmium probe (complete within approx. 20 min) and dispersion throughout the cytoplasm and organelles. The near-infrared (NIR) emission of the osmium complex (λmax 726 nm) coincides well with the biological optical window and this facilitated luminescent and luminescence lifetime imaging of the cell which was well resolved from cell autofluorescence. The large Stokes shift of the emission also permitted resonance Raman mapping of the dye within CHO cells. Rather surprisingly, the osmium conjugate exhibited very low cytotoxicity when incubated both in the dark and under visible irradiation. This was attributed to the remarkable stability of this complex which was reflected by the complete absence of photo-bleaching of the complex even under extended continuous irradiation. In addition, when compared to its ruthenium analogue its luminescence was short-lived in water therefore rendering it insensitive to O2.

  5. C-H bond activation of the methyl group of the supporting ligand in an osmium(III) complex upon reaction with H2O2: formation of an organometallic osmium(IV) complex.

    PubMed

    Sugimoto, Hideki; Ashikari, Kenji; Itoh, Shinobu

    2013-01-18

    Oxidation of the hydroxoosmium(III) complex resulted in C-H bond activation of the methyl group of the supporting ligand (N,N'-dimethyl-2,11-diaza[3.3](2,6)pyridinophane). The product was an osmium(IV) complex exhibiting a seven-coordinate structure with an additional Os-CH(2) bond.

  6. Regulation of intestinal homeostasis by the ulcerative colitis-associated gene RNF186.

    PubMed

    Fujimoto, Kosuke; Kinoshita, Makoto; Tanaka, Hiroo; Okuzaki, Daisuke; Shimada, Yosuke; Kayama, Hisako; Okumura, Ryu; Furuta, Yoki; Narazaki, Masashi; Tamura, Atsushi; Hatakeyama, Shigetsugu; Ikawa, Masahito; Tsuchiya, Kiichiro; Watanabe, Mamoru; Kumanogoh, Atsushi; Tsukita, Sachiko; Takeda, Kiyoshi

    2017-03-01

    Genome-wide association studies and subsequent deep sequencing analysis have identified susceptible loci for inflammatory bowel diseases (IBDs) including ulcerative colitis (UC). A gene encoding RING finger protein 186 (RNF186) is located within UC-susceptible loci. However, it is unclear whether RNF186 is involved in IBD pathogenesis. Here, we show that RNF186 controls protein homeostasis in colonic epithelia and regulates intestinal inflammation. RNF186, which was highly expressed in colonic epithelia, acted as an E3 ligase mediating polyubiquitination of its substrates. Permeability of small organic molecules was augmented in the intestine of Rnf186(-/-) mice. Increased expression of several RNF186 substrates, such as occludin, was found in Rnf186(-/-) colonic epithelia. The disturbed protein homeostasis in Rnf186(-/-) mice correlated with enhanced endoplasmic reticulum (ER) stress in colonic epithelia and increased sensitivity to intestinal inflammation after dextran sulfate sodium (DSS) treatment. Introduction of an UC-associated Rnf186 mutation led to impaired E3 ligase activity and increased sensitivity to DSS-induced intestinal inflammation in mice. Thus, RNF186 maintains gut homeostasis by controlling ER stress in colonic epithelia.

  7. Ruthenium- and osmium-arene-based paullones bearing a TEMPO free-radical unit as potential anticancer drugs.

    PubMed

    Arion, Vladimir B; Dobrov, Anatolie; Göschl, Simone; Jakupec, Michael A; Keppler, Bernhard K; Rapta, Peter

    2012-09-04

    A modified paullone ligand bearing a TEMPO free-radical unit (HL) and its ruthenium(II) and osmium(II)-arene complexes [M(p-cymene)(HL)Cl]Cl·nH(2)O (M = Ru, Os) exhibit high antiproliferative activity in human cancer cell lines.

  8. Three-Dimensional Structural Analysis of MgO-Supported Osmium Clusters by Electron Microscopy with Single-Atom Sensitivity

    SciTech Connect

    Aydin, C.; Kulkarni, Apoorva; Chi, Miaofang; Browning, Nigel D.; Gates, Bruce C.

    2013-05-10

    Size, shape, nuclearity: Aberration-corrected scanning transmission electron microscopy was used to determine the 3D structures of MgO-supported Os3, Os4, Os5, and Os10 clusters, which have structures nearly matching those of osmium carbonyl compounds with known crystal structures. The samples are among the best-defined supported catalysts.

  9. Short review of high-pressure crystal growth and magnetic and electrical properties of solid-state osmium oxides

    NASA Astrophysics Data System (ADS)

    Yamaura, Kazunari

    2016-04-01

    High-pressure crystal growth and synthesis of selected solid-state osmium oxides, many of which are perovskite-related types, are briefly reviewed, and their magnetic and electrical properties are introduced. Crystals of the osmium oxides, including NaOsO3, LiOsO3, and Na2OsO4, were successfully grown under high-pressure and high-temperature conditions at 6 GPa in the presence of an appropriate amount of flux in a belt-type apparatus. The unexpected discovery of a magnetic metal-insulator transition in NaOsO3, a ferroelectric-like transition in LiOsO3, and high-temperature ferrimagnetism driven by a local structural distortion in Ca2FeOsO6 may represent unique features of the osmium oxides. The high-pressure and high-temperature synthesis and crystal growth has played a central role in the development of solid-state osmium oxides and the elucidation of their magnetic and electronic properties toward possible use in multifunctional devices.

  10. Homogeneous electrochemical detection of hippuric acid in urine based on the osmium-antigen conjugate.

    PubMed

    Jeon, Won-Yong; Choi, Young-Bong; Kim, Hyug-Han

    2013-07-22

    A homogeneous electrochemical immunoassay is based on the interaction of osmium-antigen conjugate with its antibody. The novelty presented herein is the direct conjugation of the osmium complex to a small antigen and the application of the quantitative analysis of the antigen and its antibody as the electrical signal for homogeneous immunoassay. The small antigen chosen is hippuric acid (HA), a major urinary metabolite in toluene-exposed humans. As a redox mediator, [Os(4,4'-dimethoxy-2,2'-bipyridine)2(4-aminomethylpyridine-HA)Cl](+/2+) (Os-HA antigen) has been synthesized and characterized on screen-printed carbon electrodes. The synthesized Os-HA antigen shows reversible redox peaks at E(½)=0.056 V versus Ag/AgCl. The homogeneous competitive immunoassay relies on the interaction between Os-HA antigen conjugate and free antigen to its antibody, which can generate electrical signals linearly proportional to the free antigen monitored by cyclic voltammetry and differential pulse voltammetry in the range of 10 μg mL(-1) to 5.12 mg mL(-1). The cutoff concentration of HA in urine samples is 2.0 mg mL(-1), so the method can be used to develop a HA immunosensor. Moreover, the proposed homogeneous electrochemical immunoassay method can be applied to detect low concentrations of small antigens found in the healthcare area.

  11. Electrochemical communication between heterotrophically grown Rhodobacter capsulatus with electrodes mediated by an osmium redox polymer.

    PubMed

    Hasan, Kamrul; Patil, Sunil A; Górecki, Kamil; Leech, Dónal; Hägerhäll, Cecilia; Gorton, Lo

    2013-10-01

    The metabolically versatile purple bacteria Rhodobacter capsulatus was investigated to check its possible applicability in biofuel cells and electrochemical microbial biosensors. The wild type strain ATCC 17015 and mutant strain 37b4 lacking the lipopolysaccharide capsule was compared for their ability to communicate with electrodes modified with an osmium redox polymer. In this work, aerobic heterotrophically grown R. capsulatus were used to screen for efficient cell-electrode communication for later implementation using photoheterotrophically grown bacteria. The bacterial cells embedded in the osmium polymer matrix demonstrated efficient electrical "wiring" with the electrodes and were able to generate a noticeable current with succinate as substrate. Interestingly, at 2mM succinate the wild type strain showed much better bioelectrocatalytic current generation (4.25 μA/cm(2)) than the strain lacking capsule (1.55 μA/cm(2)). The wild type strain also exhibited a stable current response for longer time, demonstrating that the bacterial lipopolysaccharide in fact enhances the stability of the polymer matrix layer of the modified electrode. Control experiments with R. capsulatus without any mediator did not show any current irrespective of the capsule presence. This demonstrates that development of photosensors and other light driven bioelectrochemical devices could be feasible using R. capsulatus and will be at focus for future studies.

  12. Osmium-Based Pyrimidine Contrast Tags for Enhanced Nanopore-Based DNA Base Discrimination.

    PubMed

    Henley, Robert Y; Vazquez-Pagan, Ana G; Johnson, Michael; Kanavarioti, Anastassia; Wanunu, Meni

    2015-01-01

    Nanopores are a promising platform in next generation DNA sequencing. In this platform, an individual DNA strand is threaded into nanopore using an electric field, and enzyme-based ratcheting is used to move the strand through the detector. During this process the residual ion current through the pore is measured, which exhibits unique levels for different base combinations inside the pore. While this approach has shown great promise, accuracy is not optimal because the four bases are chemically comparable to one another, leading to small differences in current obstruction. Nucleobase-specific chemical tagging can be a viable approach to enhancing the contrast between different bases in the sequence. Herein we show that covalent modification of one or both of the pyrimidine bases by an osmium bipyridine complex leads to measureable differences in the blockade amplitudes of DNA molecules. We qualitatively determine the degree of osmylation of a DNA strand by passing it through a solid-state nanopore, and are thus able to gauge T and C base content. In addition, we show that osmium bipyridine reacts with dsDNA, leading to substantially different current blockade levels than exhibited for bare dsDNA. This work serves as a proof of principle for nanopore sequencing and mapping via base-specific DNA osmylation.

  13. Hydrolysis and cytotoxic properties of osmium(II)/(III)-DMSO-azole complexes. Short communication.

    PubMed

    Egger, Alexander; Cebrián-Losantos, Berta; Stepanenko, Iryna N; Krokhin, Artem A; Eichinger, Rene; Jakupec, Michael A; Arion, Vladimir B; Keppler, Bernhard K

    2008-08-01

    The antiproliferative properties of the osmium(II) complexes cis,fac-[Os(II)Cl(2)(DMSO)(3)(L)] and trans,cis,cis-[Os(II)Cl(2)(DMSO)(2)(L)(2)] (L = 1H-pyrazole, 1H-imidazole) were studied in three human cancer cell lines, namely 41M (ovary), SK-BR-3 (breast), and SW480 (colon). Their activities were compared with those of osmium(III) and ruthenium(III) NAMI-A type complexes on HT-29 (colon) and SK-BR-3 cancer cell lines. While IC(50) values of all the Os(II) complexes were found to be >1000 microM in all cell lines, Os and Ru-NAMI-A type complexes showed remarkable antiproliferative activity. The marginal in vitro cytotoxicity of the Os(II) compounds is presumably attributed to their resistance to hydrolysis. However, the Os-NAMI-A complexes, which are also kinetically stable in aqueous solution, showed reasonable antiproliferative activity in vitro when compared with the analogous Ru compounds and with the Os(II)-DMSO-azole species, indicating that hydrolysis might be not a prerequisite for the antitumor activity of Os-NAMI-A type complexes.

  14. Magneto-Transport Studies of Molecular Beam Epitaxial Grown Osmium Silicides

    NASA Astrophysics Data System (ADS)

    Cottier, Ryan; Zhao, Wei; Amir, Fatima; Hossain, Khalid; Anibou, Noureddine; Donner, Wolfgang; Golding, Terry

    2006-03-01

    Semiconducting transition metal silicides present a possible solution to on-chip integration of optical and electronic Si-based circuitry. Two phases of osmium silicide (OsSi2 and Os2Si3) are predicted to have promising optical characteristics but require additional development to fully determine their feasibility for high-quality devices. This study has been motivated by reports that OsSi2 has a bandgap between 1.4--1.8eV [1, 2] and Os2Si3 may have a direct bandgap of 0.95 eV [3] or 2.3 eV [1]. In this paper we will present temperature dependent (20 < T < 300 K) magneto Hall measurements of molecular beam epitaxial grown osmium silicide thin films. Os and Si were coevaporated onto Si(100) substrates at varying growth rates and temperatures. XRD was performed in order to identify the silicide phases present. We will discuss our results in relation to the known phase diagrams and our growth parameters. [1] L. Schellenberg et al., J. Less-Common Met. 144, 341 (1988). [2] K. Mason and G. Müller-Vogt, J. Appl. Phys. 63, 34 (1983). [3] A. B. Filonov et al., Phys. Rev. B 60(24), 16494 (1999).

  15. Iridium- and Osmium-decorated Reduced Graphenes as Promising Catalysts for Hydrogen Evolution.

    PubMed

    Lim, Chee Shan; Sofer, Zdeněk; Toh, Rou Jun; Eng, Alex Yong Sheng; Luxa, Jan; Pumera, Martin

    2015-06-22

    Renewable energy sources are highly sought after as a result of numerous worldwide problems concerning the environment and the shortage of energy. Currently, the focus in the field is on the development of catalysts that are able to provide water splitting catalysis and energy storage for the hydrogen evolution reaction (HER). While platinum is an excellent material for HER catalysis, it is costly and rare. In this work, we investigated the electrocatalytic abilities of various graphene-metal hybrids to replace platinum for the HER. The graphene materials were doped with 4f metals, namely, iridium, osmium, platinum and rhenium, as well as 3d metals, namely, cobalt, iron and manganese. We discovered that a few hybrids, in particular iridium- and osmium-doped graphenes, have the potential to become competent electrocatalysts owing to their low costs and-more importantly-to their promising electrochemical performances towards the HER. One of the more noteworthy observations of this work is the superiority of these two hybrids over MoS2 , a well-known electrocatalyst for the HER.

  16. Coupling osmium complexes to epoxy-functionalised polymers to provide mediated enzyme electrodes for glucose oxidation.

    PubMed

    Ó Conghaile, Peter; Pöller, Sascha; MacAodha, Domhnall; Schuhmann, Wolfgang; Leech, Dónal

    2013-05-15

    Newly synthesised osmium complex-modified redox polymers were tested for potential application as mediators in glucose oxidising enzyme electrodes for application to biosensors or biofuel cells. Coupling of osmium complexes containing amine functional groups to epoxy-functionalised polymers of variable composition provides a range of redox polymers with variation possible in redox potential and physicochemical properties. Properties of the redox polymers as mediators for glucose oxidation were investigated by co-immobilisation onto graphite with glucose oxidase or FAD-dependent glucose dehydrogenase using a range of crosslinkers and in the presence and absence of multiwalled carbon nanotubes. Electrodes prepared by immobilising [P20-Os(2,2'-bipyridine)2(4-aminomethylpyridine)Cl].PF6, carbon nanotubes and glucose oxidase exhibit glucose oxidation current densities as high as 560μAcm(-2) for PBS containing 100mM glucose at 0.45V vs. Ag/AgCl. Films prepared by crosslinking [P20-Os(4,4'-dimethoxy-2,2'-bipyridine)2(4-aminomethylpyridine)Cl].PF6, an FAD-dependent glucose dehydrogenase, and carbon nanotubes achieve current densities of 215μAcm(-2) in 5mM glucose at 0.2V vs. Ag/AgCl, showing some promise for application to glucose oxidising biosensors or biofuel cells.

  17. Structure of the K{sup {pi}=}4{sup +} bands in {sup 186,188}Os

    SciTech Connect

    Phillips, A. A.; Garrett, P. E.; Demand, G. A.; Finlay, P.; Green, K. L.; Leach, K. G.; Schumaker, M. A.; Svensson, C. E.; Wong, J.; Lo Iudice, N.; Sushkov, A. V.; Bettermann, L.; Braun, N.; Burke, D. G.; Faestermann, T.; Kruecken, R.; Wirth, H.-F.; Hertenberger, R.

    2010-09-15

    The ({sup 3}He, d) single-proton stripping reaction has been performed on targets of {sup 185,187}Re to investigate the structures of the 4{sub 3}{sup +} states in {sup 186,188}Os. The experiment employed 30 MeV {sup 3}He beams, and the reaction products were analyzed with a Q3D spectrograph. Absolute cross sections were determined at nine angles between 5 deg. and 50 deg. for states up to approximately 3 MeV in excitation energy. Large (5/2){sup +}[402]{sub {pi}+}(3/2){sup +}[402]{sub {pi}}two-quasiparticle components are deduced for the 4{sub 3}{sup +} levels of both isotopes. Their magnitudes are in agreement with calculations performed using the quasiparticle phonon model, which predicts a coexistence of a large hexadecapole with a smaller, but sizable, {gamma}-{gamma} component in the 4{sub 3}{sup +}.

  18. A New Lifshitz Transition and the Equation of State of Osmium

    SciTech Connect

    Occelli, F; Aracne, C M; Teter, D M; Hanfland, M; Canny, B; Couzinet, B; Chervin, J; Badro, J; Farber, D L

    2003-11-05

    We have measured the equation of state (EoS) of osmium to 75 GPa under hydrostatic conditions at room temperature using angle dispersive x-ray diffraction. A least-squares fit of the data using a third order Birch-Murnaghan EoS yields K{sub 0} = 411 {+-} 6 GPa and K'{sub 0} = 4.0 {+-} 0.2, showing osmium is in fact more compressible than diamond. Most importantly, we have documented an anomaly in the compressibility at 20.3 GPa associated with a large discontinuity in the first pressure derivative of the c/a ratio. This discontinuity likely arises from the collapse of the small hole-ellipsoid in the Fermi surface near the L point. There has been much interest in the possibility of a Lifshitz [1] or electronic topological transition (ETT) in zinc at high-pressure near 10 GPa. Interestingly, while the experimental data remain somewhat ambiguous [2-5], most simulations suggest the ETT exists in this pressure range [6-8]. Recently, Steinle-Neumann et al. [8] have shown that the transition arises from changes in the band structure near the high-symmetry point K where three bands cross the Fermi surface upon compression. Thus one might expect that other hcp metals should exhibit similar phenomena. The hcp 4d and 5d transition elements Re, Os and Ru are known to be among the densest and stiffest metals [9,10] suggesting that these might in fact be poor candidates in which to look for such effects. In osmium however, experimental and theoretical results [11,12] have shown the existence of small local maxima in the band structure just above the Fermi energy near the high-symmetry point L on the zone boundary [11]. These structures might potentially fall below the Fermi energy upon compression and give rise to an ETT. Osmium is of further interest as recent EoS measurements by Cynn et al. [13] have suggested that Os (K{sub 0} = 462 GPa and K'{sub 0} = 2.4) has the lowest known compressibility, lower even than diamond (K{sub 0} = 446 GPa and K'{sub 0} = 3) [14]. This

  19. Rhenium-osmium isotope systematics of ordinary chondrites and iron meteorites

    NASA Technical Reports Server (NTRS)

    Walker, R. J.; Morgan, J. W.; Horan, M. F.; Grossman, J. N.

    1993-01-01

    Using negative thermal ionization mass spectrometry, Re and Os abundances were determined by isotope dilution and Os-187/Os-186 measured in 11 ordinary chondrites, and also in 1 IIB and 3 IIIB irons. In addition, Os-186/Os-188 and Os-189/Os-188 ratios were precisely determined for 3 unspiked ordinary chondrites as a means of constraining the intensity of any neutron irradiation these meteorites may have experienced.

  20. POX 186: A Dwarf Galaxy in the Process of Formation?

    NASA Astrophysics Data System (ADS)

    Corbin, Michael R.; Vacca, William D.

    2002-12-01

    We present deep U-, V-, and I-band images of the ``ultracompact'' blue dwarf galaxy POX 186 obtained with the Planetary Camera 2 of the Hubble Space Telescope. We have also obtained a near-ultraviolet spectrum of the object with the Space Telescope Imaging Spectrograph and combine this with a new ground-based optical spectrum. The images confirm the galaxy to be extremely small, with a maximum extent of only 300 pc, a luminosity of ~10-4L*, and an estimated mass of ~107 Msolar. Its morphology is highly asymmetric, with a tail of material on its western side that may be tidal in origin. The U-band image shows this tail to be part of a stream of material in which stars have recently formed. Most of the star formation in the galaxy is, however, concentrated in a central, compact (d~10-15 pc) star cluster. We estimate this cluster to have a total mass of ~105 Msolar, to be forming stars at a rate of less than 0.05 yr-1, and to have a maximum age of a few million years. The outer regions of the galaxy are significantly redder than the cluster, with V-I colors consistent with a population dominated by K and M stars. From our analysis of the optical spectrum we find the galaxy to have a metallicity Z~=0.06 Zsolar and to contain a significant amount of internal dust [E(B-V)~=0.28] both values agree with previous estimates. While these results rule out earlier speculation that POX 186 is a protogalaxy, its morphology, mass, and active star formation suggest that it represents a recent (within ~108 yr) collision between two clumps of stars of subgalactic size (~100 pc). POX 186 may thus be a very small dwarf galaxy that, dynamically speaking, is still in the process of formation. This interpretation is supported by the fact that it resides in a void, so its morphology cannot be explained as the result of an encounter with a more massive galaxy. Clumps of stars this small may represent the building blocks required by hierarchical models of galaxy formation, and these results

  1. Polynuclear ruthenium, osmium and gold complexes. The quest for innovative anticancer chemotherapeutics.

    PubMed

    Hartinger, Christian G; Phillips, Andrew D; Nazarov, Alexey A

    2011-01-01

    Polynuclear compounds are a relatively new and successful approach in metal-based cancer chemotherapy as typified by the trinuclear Pt compound BBR3464 which was evaluated in clinical trials. In this review, we discuss newer developments of polynuclear ruthenium, osmium and gold complexes, focusing on their anticancer activity. The compounds presented are often supposed to exert their anticancer activity by different modes of action as compared to established drugs, including newly proposed mechanisms such as enzyme inhibition, crosslinking of biomacromolecules or through photo-activation, though many of the examples are also capable of binding to DNA nucleobases. Important metabolization and chemical characteristics of such compounds are discussed, and if the appropriate data is available, molecular modes of action are highlighted.

  2. Striking difference in antiproliferative activity of ruthenium- and osmium-nitrosyl complexes with azole heterocycles.

    PubMed

    Büchel, Gabriel E; Gavriluta, Anatolie; Novak, Maria; Meier, Samuel M; Jakupec, Michael A; Cuzan, Olesea; Turta, Constantin; Tommasino, Jean-Bernard; Jeanneau, Erwann; Novitchi, Ghenadie; Luneau, Dominique; Arion, Vladimir B

    2013-06-03

    Ruthenium nitrosyl complexes of the general formulas (cation)(+)[cis-RuCl4(NO)(Hazole)](-), where (cation)(+) = (H2ind)(+), Hazole = 1H-indazole (Hind) (1c), (cation)(+) = (H2pz)(+), Hazole = 1H-pyrazole (Hpz) (2c), (cation)(+) = (H2bzim)(+), Hazole = 1H-benzimidazole (Hbzim) (3c), (cation)(+) = (H2im)(+), Hazole = 1H-imidazole (Him) (4c) and (cation)(+)[trans-RuCl4(NO)(Hazole)](-), where (cation)(+) = (H2ind)(+), Hazole = 1H-indazole (1t), (cation)(+) = (H2pz)(+), Hazole = 1H-pyrazole (2t), as well as osmium analogues of the general formulas (cation)(+)[cis-OsCl4(NO)(Hazole)](-), where (cation)(+) = (n-Bu4N)(+), Hazole =1H-indazole (5c), 1H-pyrazole (6c), 1H-benzimidazole (7c), 1H-imidazole (8c), (cation)(+) = Na(+); Hazole =1H-indazole (9c), 1H-benzimidazole (10c), (cation)(+) = (H2ind)(+), Hazole = 1H-indazole (11c), (cation)(+) = H2pz(+), Hazole = 1H-pyrazole (12c), (cation)(+) = (H2im)(+), Hazole = 1H-imidazole (13c), and (cation)(+)[trans-OsCl4(NO)(Hazole)](-), where (cation)(+) = n-Bu4N(+), Hazole = 1H-indazole (5t), 1H-pyrazole (6t), (cation)(+) = Na(+), Hazole = 1H-indazole (9t), (cation)(+) = (H2ind)(+), Hazole = 1H-indazole (11t), (cation)(+) = (H2pz)(+), Hazole = 1H-pyrazole (12t), have been synthesized. The compounds have been comprehensively characterized by elemental analysis, ESI mass spectrometry, spectroscopic techniques (IR, UV-vis, 1D and 2D NMR) and X-ray crystallography (1c·CHCl3, 1t·CHCl3, 2t, 3c, 6c, 6t, 8c). The antiproliferative activity of water-soluble compounds (1c, 1t, 3c, 4c and 9c, 9t, 10c, 11c, 11t, 12c, 12t, 13c) in the human cancer cell lines A549 (nonsmall cell lung carcinoma), CH1 (ovarian carcinoma), and SW480 (colon adenocarcinoma) has been assayed. The effects of metal (Ru vs Os), cis/trans isomerism, and azole heterocycle identity on cytotoxic potency and cell line selectivity have been elucidated. Ruthenium complexes (1c, 1t, 3c, and 4c) yielded IC50 values in the low micromolar concentration range. In contrast to most

  3. A Crossover from High Stiffness to High Hardness: The Case of Osmium and Its Borides

    NASA Astrophysics Data System (ADS)

    Bian, Yongming; Liu, Xiaomei; Li, Anhu; Liang, Yongcheng

    2016-09-01

    Transition-metal light-element compounds are currently raising great expectations for hard and superhard materials. Using the widely attracting osmium (Os) and its borides (OsB, Os2B3 and OsB2) as prototypes, we demonstrate by first-principles calculations that heavy transition metals, which possess high stiffness but low hardness, can be converted into highly hard materials by incorporating of light elements to form compounds. Such a crossover is a manifestation that the underlying sources of high stiffness and high hardness are fundamentally different. The stiffness is related to elastic deformation that is closely associated with valence electron density, whereas the hardness depends strongly on plastic deformation that is determined by bonding nature. Therefore, the incorporation of light atoms into transition metal should be a valid pathway of designing hard and superhard materials. This strategy is in principle also applicable to other transition-metal borides, carbides, and nitrides.

  4. Borinium cations as sigma-B-H ligands in osmium complexes.

    PubMed

    Esteruelas, Miguel A; Fernández-Alvarez, Francisco J; López, Ana M; Mora, Malka; Oñate, Enrique

    2010-04-28

    The complex OsH(2)Cl(2)(P(i)Pr(3))(2) reacts with pinacolborane, Me(2)NH-BH(3), and (t)BuNH(2)-BH(3) to give the complexes OsH(2)Cl{eta(2)-HBOC(CH(3))(2)C(CH(3))(2)OBpin}(P(i)Pr(3))(2) and OsH(2)Cl(eta(2)-HBNR(1)R(2))(P(i)Pr(3))(2) (R(1) = R(2) = Me; R(1) = H, R(2) = (t)Bu) containing monosubstituted alkoxy- and amidoborinium cations coordinated as sigma-B-H ligands. The process is proposed to take place via the electrophilic 14-valence-electron fragment OsHCl(P(i)Pr(3))(2), which promotes hydride transfer from the corresponding borane to the osmium atom.

  5. Osmium, ruthenium, iridium and uranium in silicates and chromite from the eastern Bushveld Complex, South Africa

    USGS Publications Warehouse

    Gijbels, R.h.; Millard, H.T.; Desborough, G.A.; Bartel, A.J.

    1974-01-01

    Osmium, ruthenium, iridium and uranium contents were determined in eight ortho pyroxene, seven plagioclase, and three chromite mineral separates from the eastern Bushveld Complex. Neutron activation analysis was used to measure the platinum metals, and uranium was determined by a fission track technique. The platinum metals were found to be present within each mine??ral in the proportions Os:Ru:Ir = 1:7:1, while the concentrations of these metals in the minerals are in the ratios orthopyroxene:plagioclase:chromite = 1:16:700. The concentration of uranium was found to range from 11 to 66 ppb (parts per billion) and not to vary significantly from mineral to mineral. The data for the platinum metals are consistent with a model in which the eastern Bushveld Complex was formed by the fractional crystallization of two separately injected magmas. A computer fit of this model to these data indicates that the initial concentrations of Os, Ru and Ir in the first magma were 0.24, 2.0 and 0.21 ppb and in the second magma were 0.16, 1.1 and 0.18 ppb, respectively. The fit also yields the distribution coefficients for the partitioning between the liquid and cumulus orthopyroxene, cumulus plagioclase and cumulus chromite. These coefficients (mineral/liquid) for osmium are 4.5, 66 and 2700; for ruthenium, they are 5, 65 and 2700; and for iridium, they are 4, 60 and 1600. To make this fit, it was necessary to hypothesize the existence of two types of chromite: one type with a large distribution coefficient, presumably formed as a cumulus phase at high temperature, and another, more prevalent type with a smaller distribution coefficient, which may have been formed by postcumulus growth at a lower temperature. This hypothesis is supported by data for coexisting chromite-silicate pairs, which indicate that the chromite grains expelled these platinum metals as they cooled. ?? 1974.

  6. An osmium(III)/osmium(V) redox couple generating Os(V)(O)(OH) center for cis-1,2-dihydroxylation of alkenes with H2O2: Os complex with a nitrogen-based tetradentate ligand.

    PubMed

    Sugimoto, Hideki; Kitayama, Kazuhiro; Mori, Seiji; Itoh, Shinobu

    2012-11-21

    For the synthesis of the 1,2-diols, cis-1,2-dihydroxylation of alkenes catalyzed by osmium(VIII) tetroxide (OsO(4)) is a powerful method. However, OsO(4) is quite toxic due to its highly volatile and sublimable nature. Thus, the development of alternative catalysts for cis-1,2-dihydroxylation of alkenes is highly challenging. Our approach involves the use of a nitrogen-based tetradentate ligand, tris(2-pyridylmethyl)amine (tpa), for an osmium center to develop a new osmium catalyst and hydrogen peroxide (H(2)O(2)) as a cheap and environmentally benign oxidant. The new Os-tpa complex acts as a very efficient turnover catalyst for syn-selective dihydroxylation of various alkenes (turnover number ∼1000) in aqueous media, and H(2)O(2) oxidant is formally incorporated into the products quantitatively (100% atom efficiency). The reaction intermediates involved in the catalytic cycle have been isolated and characterized crystallographically as [Os(III)(OH)(H(2)O)(tpa)](2+) and [Os(V)(O)(OH)(tpa)](2+) complexes. The observed syn-selectivity, structural characteristics of the intermediates, and kinetic studies have suggested a concerted [3 + 2]-cycloaddition mechanism between [Os(V)(O)(OH)(tpa)](2+) and alkenes, which is strongly supported by DFT calculations.

  7. An osmium-free method of epon embedment that preserves both ultrastructure and antigenicity for post-embedding immunocytochemistry.

    PubMed

    Phend, K D; Rustioni, A; Weinberg, R J

    1995-03-01

    Immunocytochemistry for amino acids with post-embedding gold is compatible with glutaraldehyde fixation, osmication, and embedding in epoxy-based plastics, but immunogold detection of larger molecules in the central nervous system commonly requires special procedures, e.g. minimizing exposure to glutaraldehyde, eliminating osmium, cryosectioning, and/or embedding in acrylic plastics. These make samples more difficult to prepare and view and may compromise structural preservation. We report a new technique, fixing with high levels of glutaraldehyde, replacing osmium with tannic acid followed by other heavy metals and p-phenylenediamine, and embedding in Epon. This method optimizes antigenicity while retaining the structural preservation and convenient handling of standard embedding techniques. Compared to standard Epon embedment, labeling for neuropeptides in brain and spinal cord is improved. Moreover, the present method yields excellent labeling of glutamate receptors (difficult to identify with traditional post-embedding techniques) and enables simultaneous visualization of associated neurotransmitters.

  8. Observation of 18.6-year modulation tide at the South Pole

    NASA Astrophysics Data System (ADS)

    Rydelek, P. A.; Knopoff, L.; Zürn, W.

    1982-07-01

    We have observed long-period variations in the amplitudes of the diurnal and semidiurnal gravity tides at the South Pole which we attribute to the tidal effects of the 18.6-year regression of the nodes of the lunar orbit. The observations are in agreement with theoretical values of the 18.6-year amplitude modulation of these tides.

  9. 27 CFR 17.186 - Transfer of distilled spirits to other containers.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2012-04-01 2012-04-01 false Transfer of distilled spirits to other containers. 17.186 Section 17.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND... package to other containers at any time for the purpose of facilitating the manufacture of products...

  10. 19 CFR 122.186 - Presentation of Customs access seal by other person.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 19 Customs Duties 1 2010-04-01 2010-04-01 false Presentation of Customs access seal by other person. 122.186 Section 122.186 Customs Duties U.S. CUSTOMS AND BORDER PROTECTION, DEPARTMENT OF HOMELAND... Presentation of Customs access seal by other person. If an approved Customs access seal is presented by...

  11. 30 CFR 250.186 - What reporting information and report forms must I submit?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... must I submit? 250.186 Section 250.186 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, REGULATION... may use your own computer-generated forms that are equal in size to MMS's forms. You must arrange the data on your form identical to the MMS form. If you generate your own form and it omits terms...

  12. 30 CFR 550.186 - What reporting information and report forms must I submit?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... must I submit? 550.186 Section 550.186 Mineral Resources BUREAU OF OCEAN ENERGY MANAGEMENT, DEPARTMENT... the Regional Supervisor, you may use your own computer-generated forms that are equal in size to BOEM's forms. You must arrange the data on your form identical to the BOEM form. If you generate your...

  13. Sensitive voltammetric detection of DNA damage at carbon electrodes using DNA repair enzymes and an electroactive osmium marker.

    PubMed

    Havran, Ludek; Vacek, Jan; Cahová, Katerina; Fojta, Miroslav

    2008-07-01

    This paper presents a new approach to electrochemical sensing of DNA damage, using osmium DNA markers and voltammetric detection at the pyrolytic graphite electrode. The technique is based on enzymatic digestion of DNA with a DNA repair enzyme exonuclease III (exoIII), followed by single-strand (ss) selective DNA modification by a complex of osmium tetroxide with 2,2'-bipyridine. In double-stranded DNA possessing free 3'-ends, the exoIII creates ss regions that can accommodate the electroactive osmium marker. Intensity of the marker signal measured at the pyrolytic graphite electrode responded well to the extent of DNA damage. The technique was successfully applied for the detection of (1) single-strand breaks (ssb) introduced in plasmid DNA by deoxyribonuclease I, and (2) apurinic sites generated in chromosomal calf thymus DNA upon treatment with the alkylating agent dimethyl sulfate. The apurinic sites were converted into the ssb by DNA repair endonuclease activity of the exoIII enzyme. We show that the presented technique is capable of detection of one lesion per approximately 10(5) nucleotides in supercoiled plasmid DNA.

  14. Atomically Resolved Site-Isolated Catalyst on MgO: Mononuclear Osmium Dicarbonyls formed from Os3(CO)12

    SciTech Connect

    Aydin, Ceren; kulkarni, Apoorva; Chi, Miaofang; Browning, Nigel D.; Gates, Bruce C.

    2012-01-01

    Supported triosmium clusters, formed from Os{sub 3}(CO){sub 12} on MgO, were treated in helium at 548 K for 2 h, causing fragmentation of the cluster frame and the formation of mononuclear osmium dicarbonyls. The cluster breakup and the resultant fragmented species were characterized by infrared and X-ray absorption spectroscopies, and the fragmented species were imaged by scanning transmission electron microscopy. The spectra identify the surface osmium complexes as Os(CO){sub 2}{l_brace}O{sub support}{r_brace}{sub n} (n = 3 or 4) (where the braces denote support surface atoms). The images show site-isolated Os atoms in mononuclear osmium species on MgO. The intensity analysis on the images of the MgO(110) face showed that the Os atoms were located atop Mg columns. This information led to a model of the Os(CO){sub 2} on MgO(110), with the distances approximated as those determined by EXAFS spectroscopy, which are an average over the whole MgO surface; the results imply that these complexes were located at Mg vacancies.

  15. Wiring microbial biofilms to the electrode by osmium redox polymer for the performance enhancement of microbial fuel cells.

    PubMed

    Yuan, Yong; Shin, Hyosul; Kang, Chan; Kim, Sunghyun

    2016-04-01

    An osmium redox polymer, PAA-PVI-[Os(4,4'-dimethyl-2,2'-bipyridine)2Cl]+/2+ that has been used in enzymatic fuel cells and microbial sensors, was applied for the first time to the anode of single-chamber microbial fuel cells with the mixed culture inoculum aiming at enhancing performance. Functioning as a molecular wire connecting the biofilm to the anode, power density increased from 1479 mW m(-2) without modification to 2355 mW m(-2) after modification of the anode. Evidence from cyclic voltammetry showed that the catalytic activity of an anodic biofilm was greatly enhanced in the presence of an osmium redox polymer, indicating that electrons were more efficiently transferred to the anode via co-immobilized osmium complex tethered to wiring polymer chains at the potential range of -0.3 V-+0.1 V (vs. SCE). The optimum amount of the redox polymer was determined to be 0.163 mg cm(-2).

  16. Atomically Resolved Site-Isolated Catalyst on MgO: Mononuclear Osmium Dicarbonyls formed from Os3(CO)12.

    PubMed

    Aydin, Ceren; Kulkarni, Apoorva; Chi, Miaofang; Browning, Nigel D; Gates, Bruce C

    2012-07-19

    Supported triosmium clusters, formed from Os3(CO)12 on MgO, were treated in helium at 548 K for 2 h, causing fragmentation of the cluster frame and the formation of mononuclear osmium dicarbonyls. The cluster breakup and the resultant fragmented species were characterized by infrared and X-ray absorption spectroscopies, and the fragmented species were imaged by scanning transmission electron microscopy. The spectra identify the surface osmium complexes as Os(CO)2{Osupport}n (n = 3 or 4) (where the braces denote support surface atoms). The images show site-isolated Os atoms in mononuclear osmium species on MgO. The intensity analysis on the images of the MgO(110) face showed that the Os atoms were located atop Mg columns. This information led to a model of the Os(CO)2 on MgO(110), with the distances approximated as those determined by EXAFS spectroscopy, which are an average over the whole MgO surface; the results imply that these complexes were located at Mg vacancies.

  17. The cyro-thermochromatographic separator (CTS): A new detectionand separation system for highly volatile osmium and hassium (element108) tetroxides

    SciTech Connect

    Kirbach, U.W.; Folden III, C.M.; Ginter, T.N.; Gregorich, K.E.; Lee, D.M.; Ninov, V.; Omtvedt, J.P.; Patin, J.B.; Seward, N.K.; Strellis,D.A.; Sudowe, R.; Wilk, P.A.; Zielinski, P.M.; Hoffman, D.C.; Nitsche, H.

    2002-03-08

    We implemented a new concept for heavy element chemistry research using an ion separator to separate the desired products from the beam, transfer products and other undesirable by-products prior to chemical studies. First, a Recoil product Transfer Chamber (RTC) was designed and attached to the Berkeley Gas-filled Separator (BGS) to collect and transfer the recoiling products to the chemical separation system. The RTC consists of a wire-grid-supported thin mylar foil ({le}) 200 {micro}g/cm{sup 2} that separates the BGS detector chamber, at 1.3 mbar pressure, from the chemistry system at different pressures ranging from 480 mbar to 2000 mbar. The overall transport efficiency ranged between 30% and 15%, compared to the activity measured in the focal plane detector of the BGS. The CTS was designed as a separation and {alpha}-decay detection system for the highly volatile tetroxides of osmium and hassium, element 108. The CTS, shown in figure 1, consists of two rows of 32-{alpha} detectors arranged along a negative temperature gradient. The tetroxides adsorb on the surface of one of the silicone photodiodes at a certain deposition temperature, and the nuclide is then identified by the {alpha}-decay. To test the CTS with the expected hassium homologue osmium, different {alpha}-active osmium isotopes were produced using the nuclear reactions {sup 118}Sn({sup 56}Fe, 4,5n) {sup 170,169}Os and {sup 120}Sn({sup 56}Fe, 4,5n) {sup 172,171}Os. After preseparation in the BGS, a mixture of 90% helium and 10% oxygen was used to transport the osmium to a quartz tube heated to 1225 K, where OsO{sub 4} was formed. The negative temperature gradient in the CTS ranged from 248 K to 173 K. Using a flow rate of 500 mL/min, most of the osmium activity was adsorbed at a temperature of about 203 K. From the measured {alpha}-activity distribution, an adsorption enthalpy of 40 {+-} 1 kJ/mol for OsO{sub 4} on the detector surface was calculated using Monte Carlo simulations. The results show

  18. Backscattered electron image of osmium-impregnated/macerated tissues as a novel technique for identifying the cis-face of the Golgi apparatus by high-resolution scanning electron microscopy.

    PubMed

    Koga, D; Bochimoto, H; Watanabe, T; Ushiki, T

    2016-07-01

    The osmium maceration method with scanning electron microscopy (SEM) enabled to demonstrate directly the three-dimensional (3D) structure of membranous cell organelles. However, the polarity of the Golgi apparatus (that is, the cis-trans axis) can hardly be determined by SEM alone, because there is no appropriate immunocytochemical method for specific labelling of its cis- or trans-faces. In the present study, we used the osmium impregnation method, which forms deposits of reduced osmium exclusively in the cis-Golgi elements, for preparation of specimens for SEM. The newly developed procedure combining osmium impregnation with subsequent osmium maceration specifically visualised the cis-elements of the Golgi apparatus, with osmium deposits that were clearly detected by backscattered electron-mode SEM. Prolonged osmication by osmium impregnation (2% OsO4 solution at 40°C for 40 h) and osmium maceration (0.1% OsO4 solution at 20°C for 24 h) did not significantly impair the 3D ultrastructure of the membranous cell organelles, including the Golgi apparatus. This novel preparation method enabled us to determine the polarity of the Golgi apparatus with enough information about the surrounding 3D ultrastructure by SEM, and will contribute to our understanding of the global organisation of the entire Golgi apparatus in various differentiated cells.

  19. Minimum 186 Basin levels required for operation of ECS and CWS pumps

    SciTech Connect

    Reeves, K.K.; Barbour, K.L.

    1992-10-01

    Operation of K Reactor with a cooling tower requires that 186 Basin loss of inventory transients be considered during Design Basis Accident analyses requiring ECS injection, such as the LOCA and LOPA. Since the cooling tower systems are not considered safety systems, credit is not taken for their continued operation during a LOPA or LOCA even though they would likely continue to operate as designed. Without the continued circulation of cooling water to the 186 Basin by the cooling tower pumps, the 186 Basin will lose inventory until additional make-up can be obtained from the river water supply system. Increasing the make-up to the 186 Basin from the river water system may require the opening of manually operated valves, the starting of additional river water pumps, and adjustments of the flow to L Area. In the time required for these actions a loss of basin inventory could occur. The ECS and CWS pumps are supplied by the 186 Basin. A reduction in the basin level will result in decreased pump suction head. This reduction in suction head will result in decreased output from the pumps and, if severe enough, could lead to pump cavitation for some configurations. The subject of this report is the minimum 186 Basin level required to prevent ECS and CWS pump cavitation. The reduction in ECS flow due to a reduced 186 Basin level without cavitation is part of a separate study.

  20. Origin of platinum-group mineral assemblages in a mantle tectonite at Unst deduced from mineral chemistry and osmium isotopes

    NASA Astrophysics Data System (ADS)

    Badanina, Inna Yu.; Lord, Richard A.; Malitch, Kreshimir N.; Meisel, Thomas C.

    2013-04-01

    This study assesses textural and mineral chemistry data, whole-rock and mineral separate Os-isotope compositions for distinct platinum-group mineral (PGM) inclusion assemblages in an isolated chromitite pod at Harold's Grave, which occurrs in a mantle tectonite at Unst in the Shetland Ophiolite Complex, Scotland. The investigation employed a multi-technique approach and utilized a number of analytical techniques, including electron microprobe analysis, ID ICP-MS after high pressure acid digestion, and LA MC-ICP-MS. Two distinct PGM assemblages have been recognized. They comprise a 'primary' euhedrally shaped (up to 15 μm in size) PGM assemblage, which occur as inclusions in chromite, and a modified 'secondary' subeuhedral to anhedral PGM assemblage (up to 100 μm) associated with Ru-rich pentlandite observed in cracks filled by chlorite or serpentine, interstitially to chromite grains. A 'primary' PGM assemblage is represented by solitary grains of laurite or iridian osmium and composite grains that display well defined phase boundaries between two or three distinct PGM. The latter are dominated by laurite and iridian osmium, with subordinate laurite + osmian iridium + iridian osmium and rare laurite + Ir-Rh alloy + Rh-rich sulphide (possibly prassoite). The compositional variability of associated laurite and Os-rich alloys at Harold's Grave fit the predicted compositions of experiment W-1200-0.37 of Andrews and Brenan (2002) providing unequivocal information on conditions of their genesis, with the upper thermal stability of laurite in equilibrium with Os-rich alloys estimated at 1200 - 1250° C and f(S2) of 10-0.39-10-0.07. The inconsistent grouping of different primary PGM grains argues against an origin by subsolidus exsolution from the chromite host, providing useful information on conditions of their genesis. The 'secondary' PGM assemblage is polyphase, with dominant laurite, intimately intergrown with native osmium, irarsite and Ru-rich pentlandite. This

  1. Development of a reliable analytical method for the precise extractive spectrophotometric determination of osmium(VIII) with 2-nitrobenzaldehydethiocarbohydrazone: Analysis of alloys and real sample

    NASA Astrophysics Data System (ADS)

    Zanje, Sunil B.; Kokare, Arjun N.; Suryavanshi, Vishal J.; Waghmode, Duryodhan P.; Joshi, Sunil S.; Anuse, Mansing A.

    2016-12-01

    The proposed method demonstrates that the osmium(VIII) forms complex with 2-NBATCH from 0.8 mol L- 1 HCl at room temperature. The complex formed was extracted in 10 mL of chloroform with a 5 min equilibration time. The absorbance of the red colored complex was measured at 440 nm against the reagent blank. The Beer's law was obeyed in the range of 5-25 μg mL- 1, the optimum concentration range was 10-20 μg mL- 1 of osmium(VIII) as evaluated by Ringbom's plot. Molar absorptivity and Sandell's sensitivity of osmium(VIII)-2NBATCH complex in chloroform is 8.94 × 103 L mol- 1 cm- 1 and 0.021 μg cm- 2, respectively. The composition of osmium(VIII)-2NBATCH complex was 1:2 investigated from Job's method of continuous variation, Mole ratio method and slope ratio method. The interference of diverse ions was studied and masking agents were used wherever necessary. The present method was successfully applied for determination of osmium(VIII) from binary, ternary and synthetic mixtures corresponding to alloys and real samples. The validity of the method was confirmed by finding the relative standard deviation for five determinations which was 0.29%.

  2. Development of a reliable analytical method for the precise extractive spectrophotometric determination of osmium(VIII) with 2-nitrobenzaldehydethiocarbohydrazone: Analysis of alloys and real sample.

    PubMed

    Zanje, Sunil B; Kokare, Arjun N; Suryavanshi, Vishal J; Waghmode, Duryodhan P; Joshi, Sunil S; Anuse, Mansing A

    2016-12-05

    The proposed method demonstrates that the osmium(VIII) forms complex with 2-NBATCH from 0.8molL(-1) HCl at room temperature. The complex formed was extracted in 10mL of chloroform with a 5min equilibration time. The absorbance of the red colored complex was measured at 440nm against the reagent blank. The Beer's law was obeyed in the range of 5-25μgmL(-1), the optimum concentration range was 10-20μgmL(-1) of osmium(VIII) as evaluated by Ringbom's plot. Molar absorptivity and Sandell's sensitivity of osmium(VIII)-2NBATCH complex in chloroform is 8.94×10(3)Lmol(-1)cm(-1) and 0.021μgcm(-2), respectively. The composition of osmium(VIII)-2NBATCH complex was 1:2 investigated from Job's method of continuous variation, Mole ratio method and slope ratio method. The interference of diverse ions was studied and masking agents were used wherever necessary. The present method was successfully applied for determination of osmium(VIII) from binary, ternary and synthetic mixtures corresponding to alloys and real samples. The validity of the method was confirmed by finding the relative standard deviation for five determinations which was 0.29%.

  3. Osmium isotope anomalies in chondrites: Results for acid residues and related leachates

    NASA Astrophysics Data System (ADS)

    Yokoyama, Tetsuya; O'D. Alexander, Conel M.; Walker, Richard J.

    2010-03-01

    We have investigated Os isotope anomalies in acid residues enriched in insoluble organic matter (IOM) extracted from ten primitive chondrites, acid leachates and residues of these fractions, as well as acid leachates of bulk chondrites. Osmium isotopic compositions of bulk carbonaceous, ordinary and enstatite chondrites are also reported. Consistent with prior results, bulk chondrites have homogeneous Os isotope compositions for s-, r-, and p-process nuclides that are indistinguishable from terrestrial, at the current level of resolution. In contrast, nearly all the IOM-rich residues are enriched in s-process Os, evidently due to the preferential incorporation of s-process enriched presolar grains (most likely presolar SiC). Presolar silicate grains that formed in red giant branch (RGB) or asymptotic giant branch (AGB) stars are also likely hosts of additional s-process Os in chondrites. Consistent with one prior study, Os released by weak acid leaching of bulk chondrites is slightly to strongly enriched in r-process nuclides, of which the carrier may be fine-grained presolar silicates formed in supernovae or unidentified solar phases. Collectively, the different, chemically concentrated components in these meteorites are variably enriched in s-, r-, and possibly p-process Os, of which the individual carriers must have been produced in multiple stellar environments. The lack of evidence for Os isotopic heterogeneity among bulk chondrites contrasts with evidence for isotopic heterogeneities for various other elements at approximately the same levels of resolution (e.g., Cr, Mo, Ru, Ba, Sm, and Nd). One possible explanation for this is that the heterogeneities for some elements in bulk materials reflect selective removal of some types of presolar grains as a result of nebular processes, and that because of the strong chemical differences between Os and the other elements, the Os was not significantly affected. Another possible explanation is that late-stage injection

  4. Amide-Directed Formation of Five-Coordinate Osmium Alkylidenes from Alkynes

    PubMed Central

    2015-01-01

    The amide-directed synthesis of five-coordinate osmium alkylidene derivatives from alkynes is reported. These types of complexes, which have been elusive until now because of the tendency of osmium to give hydride alkylidyne species, are prepared by reaction of the dihydride OsH2Cl2(PiPr3)2 (1) with terminal alkynes containing a distal amide group. Complex 1 reacts with N-phenylhex-5-ynamide and N-phenylhepta-6-ynamide to give OsCl2{=C(CH3)(CH2)nNH(CO)Ph}(PiPr3)2 (n = 3 (2), 4 (3)). The relative position of carbonyl and NH groups in the organic substrates has no influence on the reaction. Thus, treatment of 1 with N-(pent-4-yn-1-yl)benzamide leads to OsCl2{=C(CH3)(CH2)3NHC(O)Ph}(PiPr3)2 (4). The new compounds are intermediate species in the cleavage of the C–C triple bond of the alkynes. Under mild conditions, they undergo the rupture of the Cα–CH3 bond of the alkylidene, which comes from the alkyne triple bond, to afford six-coordinate hydride–alkylidyne derivatives. In dichloromethane, complex 2 gives a 10:7 mixture of OsHCl2{≡C(CH2)3C(O)NHPh}(PiPr3)2 (5) and OsHCl2{≡CCH(CH3)(CH2)2C(O)NHPh}(PiPr3)2 (6). The first complex contains a linear separation between the alkylidyne Cα atom and the amide group, whereas the spacer is branched in the second complex. In contrast to the case for 2, complex 4 selectively affords OsHCl2{≡C(CH2)3NHC(O)Ph}(PiPr3)2 (7). In spite of their instability, these compounds give the alkylidene–allene metathesis, being a useful entry to five-coordinate vinylidene complexes, including the dicarbon-disubstituted OsCl2(=C=CMe2)(PiPr3)2 (8) and the monosubstituted OsCl2(=C=CHCy)(PiPr3)2 (9). PMID:26877575

  5. 187Os/186Os in Lunar and Meteoritic Materials

    NASA Astrophysics Data System (ADS)

    Birck, J. L.; Allegre, C. J.

    1993-07-01

    achondrites (Juvinas, Nuevo Laredo), diogenites (Roda, Tatahouine), lunar basalts (15555, 70017) and various terrestrial basalts were analyzed. So far all extraterrestrial basalts give ^187Os/^186Os ratios below 1.3 whereas old terrestrial basalts reach up to more than 100. The concentration of Os in extraterrestrial and terrestrial basalts are similar. There is no correlation with age. Re concentrations of terrestrial basalts are about 1000 times higher than extraterrestrial basalts. This difference in behavior of Re between terrestrial context and extraterrestrial context may have several origins: combined with pressure differences in the water content of the different planetary bodies may be one cause, but our preferred interpretation is that Re is present in a different oxidation state (ReVII) under terrestrial conditions. In contrast Re(IV) should be the dominant species in the Moon and in the basaltic achondrite parent body(ies). References: [1] Herr W. et al. (1961) Z. Naturforsch., 16a, 1053. [2] Luck J. M. and Allegre C. J. (1983) Nature, 302, 130. [3] Roy-Barman M. (1993) Ph.D. thesis, Paris. [4] Greaser R. A. et al. (1991) GCA, 55, 397. [5] Volkening J. et al. (1991) Int. J. Mass Spec. Ion Proc., 105, 147. [6] Gopel C. et al. (1985) Nature, 317, 341. [7] Burnett D. S. and Wasserburg G. J. (1967) EPSL, 2, 137. [8] Birck J. L. et al. (1991) Meteoritics, 26, 318.

  6. 12 CFR 303.186 - Exemptions from insurance requirements for a state branch of a foreign bank.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 4 2010-01-01 2010-01-01 false Exemptions from insurance requirements for a state branch of a foreign bank. 303.186 Section 303.186 Banks and Banking FEDERAL DEPOSIT INSURANCE CORPORATION PROCEDURE AND RULES OF PRACTICE FILING PROCEDURES International Banking § 303.186 Exemptions...

  7. High-pressure radial X-ray diffraction study of osmium to 58 GPa

    NASA Astrophysics Data System (ADS)

    Chen, H.; He, D.; Liu, J.; Li, Y.; Peng, F.; Li, Z.; Wang, J.; Bai, L.

    2010-02-01

    Nonhydrostatic compression behavior of osmium (Os) was investigated up to 58.2 GPa using radial X-ray diffraction (RXRD) together with lattice strain theory in a diamond-anvil cell. The apparent bulk modulus of Os derived from RXRD data varies from 262 GPa to 413 GPa, depending on Ψ, the orientation of the diffraction planes with respect to the loading axis. Fitting to the third-order Birch-Murnaghan equation of state, the RXRD data obtained at Ψ = 54.7° yields a bulk modulus K0 = 390 ± 6 GPa with pressure derivative K' 0 fixed at 4. The ratio of differential stress to shear modulus t/G ranges from 0.024 to 0.029 at the pressures of 15.7-58.2 GPa. The yield strength was observed to increase with compression and reach the value of 11.7 GPa at the highest pressure. This confirms that Os is the strongest known pure metallic material compared with the reported stiff elemental metals such as W, Mo and Re. It was found that the apparent c/a ratio changed with the nonhydrostatic compression, as well as the orientation Ψ in our experiments. Moreover, the aggregate moduli of Os at high pressure were determined from the RXRD measurements.

  8. Alkyl Chain Growth on a Transition Metal Center: How Does Iron Compare to Ruthenium and Osmium?

    PubMed

    Sainna, Mala A; de Visser, Sam P

    2015-09-28

    Industrial Fischer-Tropsch processes involve the synthesis of hydrocarbons usually on metal surface catalysts. On the other hand, very few homogeneous catalysts are known to perform a Fischer-Tropsch style of reaction. In recent work, we established the catalytic properties of a diruthenium-platinum carbene complex, [(CpRu)₂(μ²-H) (μ²-NHCH₃)(μ³-C)PtCH₃(P(CH₃)₃)₂](CO)n⁺ with n=0, 2 and Cp=η⁵-C₅(CH₃)₅, and showed it to react efficiently by initial hydrogen atom transfer followed by methyl transfer to form an alkyl chain on the Ru-center. In particular, the catalytic efficiency was shown to increase after the addition of two CO molecules. As such, this system could be viewed as a potential homogeneous Fischer-Tropsch catalyst. Herein, we have engineered the catalytic center of the catalyst and investigated the reactivity of trimetal carbene complexes of the same type using iron, ruthenium and osmium at the central metal scaffold. The work shows that the reactivity should increase from diosmium to diruthenium to diiron; however, a non-linear trend is observed due to multiple factors contributing to the individual barrier heights. We identified all individual components of these reaction steps in detail and established the difference in reactivity of the various complexes.

  9. Rapid adaptation of some phytoplankton species to osmium as a result of spontaneous mutations.

    PubMed

    Marvá, Fernando; García-Balboa, Camino; Baselga-Cervera, Beatriz; Costas, Eduardo

    2014-03-01

    To understand the vulnerability of individual species to anthropogenic contamination, it is important to evaluate the different abilities of phytoplankton to respond to environmental changes induced by pollution. The ability of a species to adapt, rather than its initial tolerance, is the basis for survival under rapidly increasing levels of anthropogenic contamination. High doses of osmium (Os) cause massive destruction of diverse phytoplankton groups. In this study, we found that the coastal chlorophyte Tetraselmis suecica and the continental chlorophyte Dictyosphaerium chlorelloides were able to adapt to a lethal dose of Os. In these species, Os-resistant cells arose as a result of rare spontaneous mutations (at rates of approximately 10(-6) mutants per cell division) that occurred before exposure to Os. The mutants remained in the microalgal populations by means of mutation-selection balance. The huge size of phytoplankton populations ensures that there are always enough Os-resistant mutants to guarantee the survival of the population under Os pollution. In contrast, we observed that neither a haptophyte species from open ocean regions nor a cyanobacterium from continental freshwater were able to adapt to the lethal Os dose. Adaptation of phytoplankton to Os contamination is relevant because industrial activities are leading to a rapid increase in Os pollution worldwide.

  10. Rapid and direct determination of fructose in food: a new osmium-polymer mediated biosensor.

    PubMed

    Antiochia, Riccarda; Vinci, Giuliana; Gorton, Lo

    2013-10-15

    This paper describes the development and performance of a new rapid amperometric biosensor for fructose monitoring in food analysis. The biosensor is based on the activity of fructose dehydrogenase (FDH) immobilised into a carbon nanotube paste electrode according to two different procedures. The direct wiring of the FDH in a highly original osmium-polymer hydrogel was found to offer a better enzyme entrapment compared to the immobilisation of the enzyme in an albumin hydrogel. The optimised biosensor required only 5U of FDH and kept the 80% of its initial sensitivity after 4months. During this time, the biosensor showed a detection limit for fructose of 1μM, a large linear range between 0.1 and 5mM, a high sensitivity (1.95μAcm(-2)mM), good reproducibility (RSD=2.1%) and a fast response time (4s). Finally, the biosensor was applied for specific determination of fructose in honey, fruit juices, soft and energy drinks. The results indicated a very good agreement with those obtained with a commercial reference kit. No significant interference was observed with the proposed biosensor.

  11. Lattice strain of osmium diboride under high pressure and nonhydrostatic stress

    SciTech Connect

    Kavner, Abby; Weinberger, Michelle B.; Shahar, Anat; Cumberland, Robert W.; Levine, Jonathan B.; Kaner, Richard B.; Tolbert, Sarah H.

    2012-01-01

    The lattice strain behavior of osmium diboride—a member of a group of third-row transition metal borides associated with hard/superhard behavior—has been studied using radial diffraction in a diamond anvil cell under high pressure and non-hydrostatic stress. We interpret the average values of the measured lattice strains as a lower-bound to the lattice-plane dependent yield strengths using existing estimates for the elastic constants of OsB2, with a yield strength of 11 GPa at 27.5 GPa of hydrostaticpressure. The measured differential lattice strains show significant plane-dependent anisotropy, with the (101) lattice plane showing the largest differential strain and the (001) lattice plane showing the least strain. At the highest pressure, the a-axis develops a larger compressive strain and supports a larger differential strain than either the b or c axes. This causes an increase in the c/a ratio and a decrease in the a/b ratio especially in the maximum stress direction. The large strength anisotropy of this material points to possible ways to modulate directional mechanical properties by taking advantage of the interplay between aggregate polycrystalline texture with directional mechanical properties.

  12. Emissive osmium(II) complexes with tetradentate bis(pyridylpyrazolate) chelates.

    PubMed

    Chang, Shih-Han; Chang, Chun-Fu; Liao, Jia-Ling; Chi, Yun; Zhou, Dong-Ying; Liao, Liang-Sheng; Jiang, Tzung-Ying; Chou, Tsao-Pei; Li, Elise Y; Lee, Gene-Hsiang; Kuo, Ting-Yi; Chou, Pi-Tai

    2013-05-20

    A tetradentate bis(pyridylpyrazolate) chelate, L, is assembled by connecting two bidentate 3-(trifluoromethyl)-5-(2-pyridyl)pyrazole chelates at the 6 position of the pyridyl fragment with a phenylamido appendage. This chelate was then utilized in the synthesis of three osmium(II) complexes, namely, [Os(L)(CO)2] (4), [Os(L)(PPh2Me)2] (5), and [Os(L)(PPhMe2)2] (6). Single-crystal X-ray structural analyses were executed on 4 and 5 to reveal the bonding arrangement of the L chelate. Phosphine-substituted derivatives 5 and 6 are highly emissive in both solution and the solid state, and their photophysical properties were measured and discussed on the basis of computational approaches. For application, fabrication and analysis of organic light-emitting diodes (OLEDs) were also carried out. The OLEDs using 5 and 6 as dopants exhibit saturated red emission with maximum external quantum efficiencies of 9.8% and 9.4%, respectively, which are higher than that of the device using [Ir(piq)3] as a red-emitting reference sample. Moreover, for documentation, 5 and 6 also achieve a maximum brightness of 19540 cd·m(-2) at 800 mA·cm(-2) (11.6 V) and 12900 cd·m(-2) at 500 mA·cm(-2) (10.5 V), respectively.

  13. Development of the osmium-191 yields iridium-191m radionuclide generator

    NASA Astrophysics Data System (ADS)

    Treves, S.; Packard, A. B.

    1985-04-01

    The use of Ir-191m in radionuclide angiography has been the subject of increasing interest in recent years. The Os-191-Ir-191m generator that has been used for these studies suffers, however, from Ir-191m yield (10%/ml) and higher than desirable Os-191 breakthrough (5 x 10 to the -3%). Ir generator has been developed that has higher yield (25 to 30%/ml) and lower breakthrough ( x 10 to the -4 power %) when eluted with an eluent (0.001 M oxalic acid/0.9% saline that does not require buffering prior to injection. Studies within the last year have shown the eluate of this generator to be nontoxic at up to 100 times the expected human dose and work is in progress to obtain approval for human use of this system. While a significant improvement over past generator designs, the yield of this generator is still modest and the evaluation of new osmium complexes for use on the generator has continued. Clinical studies involving the use of Ir-191m for first pass angiography in adults and children have continued.

  14. Coronary wall imaging in mice using osmium tetroxide and micro-computed tomography

    NASA Astrophysics Data System (ADS)

    Kozlowski, Megan; Donohue, Danielle; Chen, Marcus; Daniels, Mathew; Connelly, Patricia; Jeffries, Kenneth; Clevenger, Randall; Wen, Han H.; Pai, Vinay M.

    2011-07-01

    Coronary artery disease (CAD) is a major cause of death in the United States and results from the accumulation of atherosclerotic plaques in the arteries of the heart. Plaques accumulate as the result of the retention of low-density lipoprotein (LDL) particles in the sub-endothelium of the arterial wall. In mouse aorta, these lesions form primarily at the branching sites or bifurcations. However, in the coronary system, data has shown that late-stage plaque formation occurs throughout the proximal segments of the arteries. In order to better understand plaque formation in the coronary arteries, we have developed an osmium tetroxide (OsO4) stained coronary wall imaging protocol performed using microcomputed tomography (microCT). OsO4 is a heavy metal contrast agent that readily binds to lipids. Our data in 3- to 25-week old C57BL6 wild-type mice shows that the coronary vessel walls are highlighted by the use of the contrast agent. We expect that this combination of OsO4 and microCT will allow us to investigate the coronary artery wall in atherogenesis models of mice to characterize plaque formation.

  15. 40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual...

  16. 40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... (CONTINUED) AIR PROGRAMS (CONTINUED) NOX BUDGET TRADING PROGRAM AND CAIR NOX AND SO2 TRADING PROGRAMS FOR STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual...

  17. 34 CFR 403.186 - What are the administrative cost requirements applicable to a State?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... APPLIED TECHNOLOGY EDUCATION PROGRAM What Financial Conditions Must Be Met by a State? § 403.186 What are... Education Program, the Comprehensive Career Guidance and Counseling Program, and the...

  18. Rhenium-osmium isotope systematics in meteorites. I - Magmatic iron meteorite groups IIAB and IIIAB

    NASA Technical Reports Server (NTRS)

    Morgan, John W.; Walker, Richard J.; Grossman, Jeffery N.

    1992-01-01

    Resonance ionization mass spectrometry is used to determine the Re and Os abundances by isotope dilution (ID) and to measure Os-187/Os-186 ratios from 19 iron meteorites. Abundances range from 1.4 to 4800 ppb Re, and from 13 to 65,000 ppb Os, and generally agree well with previous ID and neutron activation results. The Re and Os data suggest that abundance trends in these iron groups may be entirely explained by fractional crystallization. Whole-rock isochrons for the IIAB and IIIAB groups are statistically indistinguishable. Pooled data yield an initial Os-187/Os-186 of 0.794 +/- 0.010 Ga. Given the errors in the slope and half life, this age does not differ significantly from the canonical chondrite age of 4.56 Ga, but could be as young as 4.46 Ga.

  19. Design study: A 186 kW lightweight diesel aircraft engine

    NASA Technical Reports Server (NTRS)

    Brouwers, A. P.

    1980-01-01

    The design of an aircraft engine capable of developing 186 kW shaft power at a 7620 m altitude is described. The 186 kW design takes into account expected new developments in aircraft designs resulting in a reassessment of the power requirements at the cruise mode operation. Based on the results of this analysis a three phase technology development program is projected resulting in production dates of 1985, 1992, and 2000.

  20. A Metallacycle Fragmentation Strategy for Vinyl Transfer from Enol Carboxylates to Secondary Alcohol C-H Bonds via Osmium- or Ruthenium-Catalyzed Transfer Hydrogenation.

    PubMed

    Park, Boyoung Y; Luong, Tom; Sato, Hiroki; Krische, Michael J

    2015-06-24

    A strategy for catalytic vinyl transfer from enol carboxylates to activated secondary alcohol C-H bonds is described. Using XPhos-modified ruthenium(0) or osmium(0) complexes, enol carboxylate-carbonyl oxidative coupling forms transient β-acyloxy-oxametallacycles, which eliminate carboxylate to deliver allylic ruthenium(II) or osmium(II) alkoxides. Reduction of the metal(II) salt via hydrogen transfer from the secondary alcohol reactant releases the product of carbinol C-H vinylation and regenerates ketone and zero-valent catalyst.

  1. Abundances and isotopic compositions of rhenium and osmium in pyrite samples from the Huaibei coalfield, Anhui, China

    USGS Publications Warehouse

    Liu, Gaisheng; Chou, C.-L.; Peng, Z.; Yang, G.

    2008-01-01

    Two pyrite samples from the Shihezi Formation (Lower Permian), Huaibei coalfield, Anhui, China, have been analyzed for abundances and isotopic compositions of rhenium and osmium using negative thermal ion mass spectrometry. The Re-Os ages of the pyrites are 64.4 and 226 Ma, which are younger than the formation age of the coal seam. The pyrite samples may consist of pyrite formed at various stages during the history of coal formation. The ??Osvalues of the two pyrite samples are +17 and +18, respectively. Such high ??Osvalues are reported for the first time for recycles crustal materials from a sedimentary basin. ?? Springer-Verlag 2007.

  2. POP-pincer osmium-polyhydrides: head-to-head (Z)-dimerization of terminal alkynes.

    PubMed

    Alós, Joaquín; Bolaño, Tamara; Esteruelas, Miguel A; Oliván, Montserrat; Oñate, Enrique; Valencia, Marta

    2013-05-20

    A wide range of osmium-polyhydride complexes stabilized by the POP-pincer ligand xant(P(i)Pr2)2 (9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene) have been synthesized through cis-OsCl2{κ-S-(DMSO)4} (1, DMSO = dimethyl sulfoxide). Treatment of toluene solutions of this adduct with the diphosphine, under reflux, leads to OsCl2{xant(P(i)Pr2)2}(κ-S-DMSO) (2). The reaction of 2 with H2 in the presence of Et3N affords OsH3Cl{xant(P(i)Pr2)2} (3), which can be also prepared by addition of xant(P(i)Pr2)2 to toluene solutions of the unsaturated d(4)-trihydride OsH3Cl(P(i)Pr3)2 (5). Complex 3 reductively eliminates H2 in toluene at 90 °C. In the presence of dimethyl sulfoxide, the resulting monohydride is trapped by the S-donor molecule to give OsHCl{xant(P(i)Pr2)2}(κ-S-DMSO) (6). The reaction of 2 with H2 is sensible to the Brønsted base. Thus, in contrast to Et3N, NaH removes both chloride ligands and the hexahydride OsH6{xant(P(i)Pr2)2} (7), containing a κ(2)-P-binding diphosphine, is formed under 3 atm of hydrogen at 50 °C. Complex 7 releases a H2 molecule to yield the tetrahydride OsH4{xant(P(i)Pr2)2} (8), which can be also prepared by reaction of OsH6(P(i)Pr3)2 (9) with xant(P(i)Pr2)2. Complex 8 reduces H(+) to give, in addition to H2, the oxidized OsH4-species [OsH4(OTf){xant(P(i)Pr2)2}](+) (10, OTf = trifluoromethanesulfonate). The redox process occurs in two stages via the OsH5-cation [OsH5{xant(P(i)Pr2)2}](+) (11). The metal oxidation state four can be recovered. The addition of acetonitrile to 10 leads to [OsH2(η(2)-H2)(CH3CN){xant(P(i)Pr2)2}](2+) (12). The deprotonation of 12 yields the osmium(IV) trihydride [OsH3(CH3CN){xant(P(i)Pr2)2}](+) (13), which is also formed by addition of HOTf to the acetonitrile solutions of 8. The latter is further an efficient catalyst precursor for the head-to-head (Z)-dimerization of phenylacetylene and tert-butylacetylene. During the activation process of the tetrahydride, the bis(alkynyl)vinylidene derivatives Os

  3. Seawater osmium isotope evidence for a middle Miocene flood basalt event in ferromanganese crust records

    USGS Publications Warehouse

    Klemm, V.; Frank, M.; Levasseur, S.; Halliday, A.N.; Hein, J.R.

    2008-01-01

    Three ferromanganese crusts from the northeast, northwest and central Atlantic were re-dated using osmium (Os) isotope stratigraphy and yield ages from middle Miocene to the present. The three Os isotope records do not show evidence for growth hiatuses. The reconstructed Os isotope-based growth rates for the sections older than 10??Ma are higher than those determined previously by the combined beryllium isotope (10Be/9Be) and cobalt (Co) constant-flux methods, which results in a decrease in the maximum age of each crust. This re-dating does not lead to significant changes to the interpretation of previously determined radiogenic isotope neodymium, lead (Nd, Pb) time series because the variability of these isotopes was very small in the records of the three crusts prior to 10??Ma. The Os isotope record of the central Atlantic crust shows a pronounced minimum during the middle Miocene between 15 and 12??Ma, similar to a minimum previously observed in two ferromanganese crusts from the central Pacific. For the other two Atlantic crusts, the Os isotope records and their calibration to the global seawater curve for the middle Miocene are either more uncertain or too short and thus do not allow for a reliable identification of an isotopic minimum. Similar to pronounced minima reported previously for the Cretaceous/Tertiary and Eocene/Oligocene boundaries, possible interpretations for the newly identified middle Miocene Os isotope minimum include changes in weathering intensity and/or a meteorite impact coinciding with the formation of the No??rdlinger Ries Crater. It is suggested that the eruption and weathering of the Columbia River flood basalts provided a significant amount of the unradiogenic Os required to produce the middle Miocene minimum. ?? 2008 Elsevier B.V.

  4. Osmium NAMI-A analogues: synthesis, structural and spectroscopic characterization, and antiproliferative properties.

    PubMed

    Cebrián-Losantos, Berta; Krokhin, Artem A; Stepanenko, Iryna N; Eichinger, Rene; Jakupec, Michael A; Arion, Vladimir B; Keppler, Bernhard K

    2007-06-11

    The osmium(III) complex [(DMSO)2H][trans-OsIIICl4(DMSO)2] (1) has been prepared via stepwise reduction of OsO4 in concentrated HCl using N2H(4).2HCl and SnCl(2).2H2O in DMSO. 1 reacts with a number of azole ligands, namely, indazole (Hind), pyrazole (Hpz), benzimidazole (Hbzim), imidazole (Him), and 1H-1,2,4-triazole (Htrz), in organic solvents, affording novel complexes (H2ind)[OsIIICl4(Hind)(DMSO)] (2), (H2pz)[OsIIICl4(Hpz)(DMSO)] (3), (H2bzim)[OsIIICl4(Hbzim)(DMSO)] (4), (H2im)[OsIIICl4(Him)(DMSO)] (6), and (H2trz)[OsIIICl4(Htrz)(DMSO)] (7), which are close analogues of the antimetastatic complex NAMI-A. Metathesis reaction of 4 with benzyltriphenylphosphonium chloride in methanol led to the formation of (Ph3PCH2Ph)[OsIIICl4(Hbzim)(DMSO)] (5). The complexes were characterized by IR, UV-vis, ESI mass spectrometry, 1H NMR spectroscopy, cyclic voltammetry, and X-ray crystallography. In contrast to NAMI-A, 2-4, 6, and 7 are kinetically stable in aqueous solution and resistant to hydrolysis. Surprisingly, they show reasonable antiproliferative activity in vitro in two human cell lines, HT-29 (colon carcinoma) and SK-BR-3 (mammary carcinoma), when compared with analogous ruthenium compounds. Structure-activity relationships and the potential of the prepared complexes for further development are discussed.

  5. In vivo tumour and metastasis reduction and in vitro effects on invasion assays of the ruthenium RM175 and osmium AFAP51 organometallics in the mammary cancer model.

    PubMed

    Bergamo, A; Masi, A; Peacock, A F A; Habtemariam, A; Sadler, P J; Sava, G

    2010-01-01

    We have compared the organometallic arene complexes [(eta(6)-biphenyl)M(ethylenediamine)Cl](+) RM175 (M=Ru(II)) and its isostructural osmium(II) analogue AFAP51 (M=Os(II)) for their ability to induce cell detachment resistance from fibronectin, collagen IV and poly-l-lysine, and cell re-adhesion after treatment, their effects on cell migration and cell viability, on matrix metalloproteinases production, and on primary tumour growth of MCa mammary carcinoma, the effect of human serum albumin on their cytotoxicity. There are differences between ruthenium and osmium. The Os complex is up to 6x more potent than RM175 towards highly-invasive breast MDA-MB-231, human breast MCF-7 and human epithelial HBL-100 cancer cells, but whereas RM175 was active against MCa mammary carcinoma in vivo and caused metastasis reduction, AFAP51 was not. Intriguingly the presence of human serum albumin in the growth medium enhanced the cytotoxicity of both compounds. RM175 increased the resistance of MDA-MB-231 cells to detachment from substrates and both compounds inhibited the production of MMP-2. These data confirm the key role of ruthenium itself in anti-metastatic activity. It will be interesting to explore the activity of osmium arene complexes in other tumour models and the possibility of changing the non-arene ligands to tune the anticancer activity of osmium in vivo.

  6. A SAR study of novel antiproliferative ruthenium and osmium complexes with quinoxalinone ligands in human cancer cell lines.

    PubMed

    Ginzinger, Werner; Mühlgassner, Gerhard; Arion, Vladimir B; Jakupec, Michael A; Roller, Alexander; Galanski, Markus; Reithofer, Michael; Berger, Walter; Keppler, Bernhard K

    2012-04-12

    A series of ruthenium(II) arene complexes with 3-(1H-benzimidazol-2-yl)-1H-quinoxalin-2-one, bearing pharmacophoric groups of known protein kinase inhibitors, and related benzoxazole and benzothiazole derivatives have been synthesized. In addition, the corresponding osmium complexes of the unsubstituted ligands have also been prepared. The compounds have been characterized by NMR, UV-vis, and IR spectroscopy, ESI mass spectrometry, elemental analysis, and by X-ray crystallography. Antiproliferative activity in three human cancer cell lines (A549, CH1, SW480) was determined by MTT assays, yielding IC(50) values of 6-60 μM for three unsubstituted metal-free ligands, whereas values for the metal complexes vary in a broad range from 0.3 to 140 μM. Complexation with osmium of quinoxalinone derivatives with benzimidazole or benzothiazole results in a more consistent increase in cytotoxicity than complexation with ruthenium. For selected compounds, the capacity to induce apoptosis was confirmed by fluorescence microscopy and flow-cytometric analysis, whereas cell cycle effects are only moderate.

  7. Distribution of coniferin in differentiating normal and compression woods using MALDI mass spectrometric imaging coupled with osmium tetroxide vapor treatment.

    PubMed

    Yoshinaga, Arata; Kamitakahara, Hiroshi; Takabe, Keiji

    2016-05-01

    Matrix-assisted laser desorption/ionization mass spectrometric imaging (MALDI-MSI) was employed to detect monolignol glucosides in differentiating normal and compression woods of two Japanese softwoods, Chamaecyparis obtusa and Cryptomeria japonica Comparison of matrix-assisted laser desorption/ionization time-of-flight mass spectrometry collision-induced dissociation fragmentation analysis and structural time-of-flight (MALDI-TOF CID-FAST) spectra between coniferin and differentiating xylem also confirmed the presence of coniferin in differentiating xylem. However, as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and MALDI-TOF CID-FAST spectra of sucrose were similar to those of coniferin, it was difficult to distinguish the distribution of coniferin and sucrose using MALDI-MSI and collision-induced dissociation measurement only. To solve this problem, osmium tetroxide vapor was applied to sections of differentiating xylem. This vapor treatment caused peak shifts corresponding to the introduction of two hydroxyl groups to the C=C double bond in coniferin. The treatment did not cause a peak shift for sucrose, and therefore was effective in distinguishing coniferin and sucrose. Thus, it was found that MALDI-MSI combined with osmium tetroxide vapor treatment is a useful method to detect coniferin in differentiating xylem.

  8. Electrochemical Properties of a Thiol Monolayers Coated Gold Electrode Modified with Osmium Gel Membrane as Enzyme Sensor

    NASA Astrophysics Data System (ADS)

    Yabutani, Tomoki; Okada, Nobuyuki; Maruyama, Kenichi; Motonaka, Junko

    The electrochemical behavior of an enzyme sensor for glucose using a gold electrode modified with thiol self-assembled membrane and osmium complex gel as an electron transferring mediator has further been investigated by electrochemical analysis. The gold electrode was initially coated with aminomethanethiol self assembling mono layer membrane(thiol-SAM) and then immobilized with glucose oxidase using poly(vinylpyridine-co-allylamine) (PVP-co-AA), gel coordinated with osmium bipyridine complexes (GOD/Os-PVP-co-AA gel). The cleaning condition of the surface of the Au electrode prior to coating thiol SAM was optimized for reduction of interference caused by concomitant compounds. It was found that interfering influence was most efficiently reduced in the case of use of the Au electrode immersed into nitric acid. The current ratio with a thiol coated gold electrode modified with Os-PVP-co-AA gel in glucose solution in the presence to absence of ascorbic acid, acetaminophen, and uric acid (ID+I/II) was 1.006, 1.014, and 1.018, respectively. The peak current response of glucose in the electrode modified with thiol SAM was dropped to 60 98% as compared with that without thiol SAM.

  9. Combined in-beam electron and {gamma}-ray spectroscopy of {sup 184,186}Hg

    SciTech Connect

    Scheck, M.; Butler, P. A.; Gaffney, L. P.; Carrol, R. J.; Cox, D.; Joss, D. T.; Herzberg, R.-D.; Page, R. D.; Papadakis, P.; Watkins, H. V.; Bree, N.; Huyse, M.; Van Duppen, P.; Grahn, T.; Greenlees, P. T.; Herzan, A.; Jakobsson, U.; Jones, P.; Julin, R.; Juutinen, S.

    2011-03-15

    By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and {gamma} rays emitted in the de-excitation of excited levels in the neutron-deficient nuclei {sup 184,186}Hg was performed. The light Hg isotopes under investigation were produced using the 4n channels of the fusion-evaporation reactions of {sup 40}Ar and {sup 148,150}Sm. The measured K- and L-conversion electron ratios confirmed the stretched E2 nature of several transitions of the yrast bands in {sup 184,186}Hg. Additional information on the E0 component of the 2{sub 2}{sup +}{yields}2{sub 1}{sup +} transition in {sup 186}Hg was obtained.

  10. Rhenium-osmium isotope systematics in meteorites I: Magmatic iron meteorite groups IIAB and IIIAB

    USGS Publications Warehouse

    Morgan, J.W.; Walker, R.J.; Grossman, J.N.

    1992-01-01

    Using resonance ionization mass spectrometry (RIMS), Re and Os abundances were determined by isotope dilution (ID) and 187Os 186Os ratios measured in nineteen iron meteorites: eight from group IIAB, ten from group IIIAB, and Treysa (IIIB anomalous). Abundances range from 1.4 to 4800 ppb Re, and from 13 to 65000 ppb Os, and generally agree well with previous ID and neutron activation (NAA) results. The Re and Os data suggest that abundance trends in these iron groups may be entirely explained by fractional crystallization. Addition of late-formed metal to produce ReOs variation in the B subgroups is not essential but cannot be excluded. Whole-rock isochrons for the IIAB and IIIAB groups are statistically indistinguishable. Pooled data yield an initial 187Os 186Os of 0.794 ?? 0.010, with a slope of (7.92 ?? 0.20) ?? 10-2 corresponding to a magmatic iron meteorite age of 4.65 ?? 0.11 Ga (using a decay constant of 1.64 ?? 10-11 a-1). Given the errors in the slope and half life, this age does not differ significantly from the canonical chondrite age of 4.56 Ga, but could be as young as 4.46 Ga. ?? 1992.

  11. Excitation Functions and Yields for RE-186G Production by Proton Cyclotron

    NASA Astrophysics Data System (ADS)

    Persico, E.; Bonardi, M. L.; Groppi, F.; Zona, C.; Canella, L.; Manenti, S.; Marchetti, M.; Abbas, K.; Holzwarth, U.; Simonelli, F.

    2008-06-01

    Excitation functions and yields for the 181-186Re radionuclides were measured by the activation method on natural tungsten foils for the proton energies up to 17 MeV. A new data sets have been given for the investigated radionuclides. These results are compared both with the experimental literature values and the ones calculated by EMPIRE II code (version 2.19). In particular, the attention is focused on Re-186g due to its remarkable applications in Nuclear Medicine for metabolic radiotherapy of tumours.

  12. Osmium pyme complexes for fast hydrogenation and asymmetric transfer hydrogenation of ketones.

    PubMed

    Baratta, Walter; Ballico, Maurizio; Del Zotto, Alessandro; Siega, Katia; Magnolia, Santo; Rigo, Pierluigi

    2008-01-01

    The osmium compound trans,cis-[OsCl2(PPh3)2(Pyme)] (1) (Pyme=1-(pyridin-2-yl)methanamine), obtained from [OsCl2(PPh3)3] and Pyme, thermally isomerizes to cis,cis-[OsCl2(PPh3)(2)(Pyme)] (2) in mesitylene at 150 degrees C. Reaction of [OsCl2(PPh3)3] with Ph2P(CH2)(4)PPh2 (dppb) and Pyme in mesitylene (150 degrees C, 4 h) leads to a mixture of trans-[OsCl2(dppb)(Pyme)] (3) and cis-[OsCl2(dppb)(Pyme)] (4) in about an 1:3 molar ratio. The complex trans-[OsCl2(dppb)(Pyet)] (5) (Pyet=2-(pyridin-2-yl)ethanamine) is formed by reaction of [OsCl2(PPh3)3] with dppb and Pyet in toluene at reflux. Compounds 1, 2, 5 and the mixture of isomers 3/4 efficiently catalyze the transfer hydrogenation (TH) of different ketones in refluxing 2-propanol and in the presence of NaOiPr (2.0 mol %). Interestingly, 3/4 has been proven to reduce different ketones (even bulky) by means of TH with a remarkably high turnover frequency (TOF up to 5.7 x 10(5) h(-1)) and at very low loading (0.05-0.001 mol %). The system 3/4 also efficiently catalyzes the hydrogenation of many ketones (H2, 5.0 atm) in ethanol with KOtBu (2.0 mol %) at 70 degrees C (TOF up to 1.5 x 10(4) h(-1)). The in-situ-generated catalysts prepared by the reaction of [OsCl2(PPh3)3] with Josiphos diphosphanes and (+/-)-1-alkyl-substituted Pyme ligands, promote the enantioselective TH of different ketones with 91-96 % ee (ee=enantiomeric excess) and with a TOF of up to 1.9 x 10(4) h(-1) at 60 degrees C.

  13. Mont Albert to Buck Mountain: Provenance of Appalachian Ophiolite Chromites Using Osmium Isotopes

    NASA Astrophysics Data System (ADS)

    Minarik, W. G.; Gale, A.; Booker, C.

    2003-12-01

    Osmium 187Os/188Os isotopic ratios have been determined for chrome-rich spinels from a suite of Appalachian ophiolites thought to represent Iapetus margin mantle formed and emplaced during the Ordovician. Because Re is incompatible during mantle melting while Os is compatible, non-radiogenic initial 187Os/188Os can constrain the average source and the timing of melt extraction, especially as Os is concentrated in chromite. Radiogenic ratios indicate contamination from aged sources with high Re/Os, such as mafic or continental crust. In rocks where spinel is the only remaining primary mineral, these properties can constrain the tectonic environment of formation as well as active-margin Os transport. There is little correction for 187Os in-growth since the Ordovician due to very low sample Re. Each ultramafic unit (from Mont Albert on the Gaspé Peninsula of Québec down to the Blue Ridge of North Carolina) forms a unique cluster of 187Os/188Os ratios, spanning 1 to 3%, but the whole range is about 10%. This corresponds to a range of initial γ Os of -1 to +9, where γ Os is the percent deviation from a chondritic source at the age of formation (roughly 500 Ma). Within ophiolites where detailed mapping and other geochemical information are available, there is a correlation between mantle-like Os and tholeiitic basalts; radiogenic Os and boninites (Thetford Mines). Continental arc-related mantle chromites (Baltimore Mafic Complex; γ Os +4 to +7) are the most radiogenic. The least radiogenic are chromites from the Staten Island serpentinite and Mont Albert (γ Os -1 and 0, respectively), either indicating formation from a previously depleted source or that they predate the other Taconic ophiolites. The restricted range of each ophiolite, compared to the whole of the data set, allow provenance links to be made between isolated bodies. For example, the Buck Creek, NC ultramafic complex, which has undergone granulite facies metamorphism, (Tenthorey et al., 1996) has a

  14. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium... Platinum, Iridium, Palladium, Ruthenium, Rhodium, and Osmium. (b) The following are examples of markings...

  15. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium... Platinum, Iridium, Palladium, Ruthenium, Rhodium, and Osmium. (b) The following are examples of markings...

  16. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium... Platinum, Iridium, Palladium, Ruthenium, Rhodium, and Osmium. (b) The following are examples of markings...

  17. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium... Platinum, Iridium, Palladium, Ruthenium, Rhodium, and Osmium. (b) The following are examples of markings...

  18. 16 CFR 23.7 - Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.”

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... § 23.7 Misuse of the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium,” and “osmium.” (a) It is unfair or deceptive to use the words “platinum,” “iridium,” “palladium,” “ruthenium,” “rhodium... Platinum, Iridium, Palladium, Ruthenium, Rhodium, and Osmium. (b) The following are examples of markings...

  19. Development of a rhenium-186-labeled MAG3-conjugated bisphosphonate for the palliation of metastatic bone pain based on the concept of bifunctional radiopharmaceuticals.

    PubMed

    Ogawa, Kazuma; Mukai, Takahiro; Arano, Yasushi; Ono, Masahiro; Hanaoka, Hirofumi; Ishino, Seigo; Hashimoto, Kazuyuki; Nishimura, Hiroshi; Saji, Hideo

    2005-01-01

    Rhenium-186-1-hydroxyethylidene-1,1-diphosphonate (186Re-HEDP) has been used for the palliation of metastatic bone pain. Delayed blood clearance and high gastric uptake of radioactivity have been observed upon injection, due to the instability of (186)Re-HEDP in vivo. In this study, on the basis of the concept of bifunctional radiopharmaceuticals, we designed a stable 186Re-mercaptoacetylglycylglycylglycine (MAG3) complex-conjugated bisphosphonate, [[[[(4-hydroxy-4,4-diphosphonobutyl)carbamoylmethyl]carbamoylmethyl]carbamoylmethyl]carbamoylmethanethiolate]oxorhenium(V) (186Re-MAG3-HBP). As a precursor, [1-hydroxy-1-phosphono-4-[2-[2-[2-(2-tritylmercaptoacetylamino)acetylamino]acetylamino]acetylamino]butyl]phosphonic acid (Tr-MAG3-HBP) was synthesized by the conjugation of N-[(tritylmercapto)acetyl]glycylglycylglycine (Tr-MAG3) with the bisphosphonate analogue. After deprotection of the trityl group of Tr-MAG3-HBP, 186Re-labeling was performed by reacting 186ReO4- with SnCl2 in citrate buffer. After purification by HPLC, 186Re-MAG3-HBP showed a radiochemical purity of over 95%. To compare the stability of 186Re-MAG3-HBP and 186Re-HEDP, these (186)Re complexes were incubated in phosphate buffer. No measurable decomposition of 186Re-MAG3-HBP occurred over a 24-h period, while only approximately 30% of 186Re-HEDP remained intact 24 h postincubation. In biodistribution experiments, the radioactivity level of 186Re-MAG3-HBP in bone was significantly higher than that of (186)Re-HEDP. Blood clearance of 186Re-MAG3-HBP was faster than that of 186Re-HEDP. In addition, the gastric accumulation of 186Re-MAG3-HBP radioactivity was lower than that of 186Re-HEDP. In conclusion, 186Re-MAG3-HBP is expected to be a useful radiopharmaceutical for the palliation of metastatic bone pain.

  20. The 18.6 yr nodal cycle and its impact on tidal sedimentation

    NASA Astrophysics Data System (ADS)

    Oost, A. P.; de Haas, H.; Ijnsen, F.; van den Boogert, J. M.; de Boer, P. L.

    1993-09-01

    The 18.6 yr nodal cycle modulates tidal amplitudes and currents, and consequently sedimentation in tide-influenced sedimentary environments. Data are presented which show that such effects are obvious along the coast of the Dutch barrier islands and in the sedimentary fill of abandoned channels.

  1. 10 CFR 72.186 - Change to physical security and safeguards contingency plans.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 2 2014-01-01 2014-01-01 false Change to physical security and safeguards contingency... GREATER THAN CLASS C WASTE Physical Protection § 72.186 Change to physical security and safeguards... may, without prior Commission approval, make changes to the physical security plan, guard...

  2. 10 CFR 72.186 - Change to physical security and safeguards contingency plans.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 2 2011-01-01 2011-01-01 false Change to physical security and safeguards contingency... GREATER THAN CLASS C WASTE Physical Protection § 72.186 Change to physical security and safeguards... may, without prior Commission approval, make changes to the physical security plan, guard...

  3. 10 CFR 72.186 - Change to physical security and safeguards contingency plans.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Change to physical security and safeguards contingency... GREATER THAN CLASS C WASTE Physical Protection § 72.186 Change to physical security and safeguards... may, without prior Commission approval, make changes to the physical security plan, guard...

  4. 10 CFR 72.186 - Change to physical security and safeguards contingency plans.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 2 2012-01-01 2012-01-01 false Change to physical security and safeguards contingency... GREATER THAN CLASS C WASTE Physical Protection § 72.186 Change to physical security and safeguards... may, without prior Commission approval, make changes to the physical security plan, guard...

  5. 10 CFR 72.186 - Change to physical security and safeguards contingency plans.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 2 2013-01-01 2013-01-01 false Change to physical security and safeguards contingency... GREATER THAN CLASS C WASTE Physical Protection § 72.186 Change to physical security and safeguards... may, without prior Commission approval, make changes to the physical security plan, guard...

  6. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  7. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 4 2012-10-01 2012-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  8. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 4 2014-10-01 2014-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  9. 47 CFR 73.186 - Establishment of effective field at one kilometer.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 4 2013-10-01 2013-10-01 false Establishment of effective field at one... RADIO SERVICES RADIO BROADCAST SERVICES AM Broadcast Stations § 73.186 Establishment of effective field at one kilometer. (a) Section 73.189 provides that certain minimum field strengths are acceptable...

  10. 40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Withdrawal from CAIR NOX Annual... STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual Trading... CAIR designated representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of...

  11. 40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Withdrawal from CAIR NOX Annual... STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual Trading... CAIR designated representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of...

  12. 40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 22 2013-07-01 2013-07-01 false Withdrawal from CAIR NOX Annual... CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided... representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of the CAIR NOX opt-in unit...

  13. 40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 21 2011-07-01 2011-07-01 false Withdrawal from CAIR NOX Annual... CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided... representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of the CAIR NOX opt-in unit...

  14. 40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Withdrawal from CAIR NOX Annual... CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided... representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of the CAIR NOX opt-in unit...

  15. 40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Withdrawal from CAIR NOX Annual... CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided... representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of the CAIR NOX opt-in unit...

  16. 40 CFR 96.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 22 2012-07-01 2012-07-01 false Withdrawal from CAIR NOX Annual... STATE IMPLEMENTATION PLANS CAIR NOX Opt-in Units § 96.186 Withdrawal from CAIR NOX Annual Trading... CAIR designated representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of...

  17. 40 CFR 97.186 - Withdrawal from CAIR NOX Annual Trading Program.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 21 2014-07-01 2014-07-01 false Withdrawal from CAIR NOX Annual... CAIR NOX Opt-In Units § 97.186 Withdrawal from CAIR NOX Annual Trading Program. Except as provided... representative of the CAIR NOX opt-in unit of the acceptance of the withdrawal of the CAIR NOX opt-in unit...

  18. 9 CFR 381.186 - Cooperation of States and other jurisdictions in Federal programs.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 2 2010-01-01 2010-01-01 false Cooperation of States and other... Cooperation With States and Territories; Certification of State and Territorial Programs as at Least Equal to Federal Program § 381.186 Cooperation of States and other jurisdictions in Federal programs. Under...

  19. Bone marrow adsorbed dose of rhenium-186-HEDP and the relationship with decreased platelet counts

    SciTech Connect

    Klerk, J.M.H. de; Dieren, E.B. van; Schip, A.D. van het

    1996-01-01

    Rhenium-186(Sn)-1,1-hydroxyethylidene diphosphonate ({sup 186}Re-HEDP) has been used for palliation of metastatic bone pain. The purpose of this study was to find a relationship between the bone marrow absorbed dose and the toxicity, expressed as the percentage decrease in the peripheral blood platelet count. The bone marrow absorbed dose was calculated according to the MIRD model using data obtained from ten treatments of patients suffering from metastatic prostate cancer; noninvasive and pharmacokinetic method were used. The bone marrow doses were related to toxicity using the pharmacodynamic sigmoid E{sub max} model. The mean bone marrow absorbed doses using the noninvasive and pharmacokinetic methods were in a close range to each other (1.07 mGy/MBq and 1.02 mGy/MBq, respectively). There was a good relationship between the toxicity and the bone marrow absorbed dose (r = 0.80). Furthermore, the EDrm{sub 50} (i.e., the bone marrow absorbed dose producing a 50% platelet decrease) to bone marrow for {sup 186}Re-HEDP was on the order of 2 Gy. Although the function of normal bone marrow is affected by metastases in patients with metastatic bone disease, the MIRD model can be used to relate toxicity to the bone marrow absorbed dose after a therapeutic dosage of {sup 186}Re-HEDP. 33 refs., 1 fig., 1 tab.

  20. 187Os-186Os and He Isotope Systematics of Iceland Picrites

    NASA Astrophysics Data System (ADS)

    Brandon, A. D.; Brandon, A. D.; Graham, D.; Gautason, B.

    2001-12-01

    Iceland is one of the longest-lived modern plumes, and seismic imaging supports a model where the roots of this plume are at the base of the lower mantle. Hence, Os isotopic data for lavas from this plume are ideal for further testing the role of core-mantle chemical exchange at the site of plume generation in the lower mantle, and for addressing the origin of Os-He isotopic variation in plumes. Recent work has shown that lavas from some plume systems (Hawaii, Noril'sk-Siberia, Gorgona) show coupled enrichments in 186Os/188Os and 187Os/188Os, not observed in upper mantle materials including abyssal peridotites. Picrites from Hawaii display a positive correlation between 186Os/188Os and He isotopes (R/Ra), where range in 186Os/188Os of 0.119834+/-28 to 0.1198475+/-29 and corresponding R/Ra from +7 to +25. These systematics are consistent with a lower mantle source for the radiogenic 186Os signal in the Hawaiian plume. The coupled Os enrichments in these plumes has been attributed to core-mantle chemical exchange, consistent with generation of the Hawaiian plume at the base of the lower mantle in D". Other potentially viable models await additional scrutiny. New He isotope and high precision 186Os/188Os and 187Os/188Os measurements for Iceland picrites show unique systematics compared to Hawaii. These picrites have 187Os/188Os ranging from 0.1297 to 0.1381 and R/Ra of +9 to +18, with generally higher R/Ra correlating with higher 187Os/188Os. Unlike the Hawaiian picrites from Hualalai and Loihi, which have coupled enrichments in 186Os/188Os and 187Os/188Os, the Iceland picrites show no enrichment 186Os/188Os - 0.1198363+/-28 (2s, n=14). Such Os-He isotopic variations require one end-member source that has high R/Ra, coupled with a long term elevated Re/Os and Pt/Os similar to that of the upper mantle. These systematics are inconsistent with either known upper mantle materials or those purported for ancient recycled slabs and may be a previously unidentified component

  1. High Precision Osmium Isotope Measurements Using New Generation Thermal Ionization Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Brandon, A.

    2006-12-01

    The technique for measuring Os isotopes to high precision (e.g. +/-30-50 ppm on the 186/188 ratio, 2 sigma) via negative thermal ionization mass spectrometry (NTIMS) was established a decade ago at the University of Maryland. Recent technical advances have resulted in the production of a new generation of TIMS that allows isotopic measurements with substantial improvement in accuracy and precision. Because of the improved capability, the new generation TIMS holds great potential to examine a variety of problems in geochemistry and cosmochemistry. Over the past 5 years, I have refined the technique for higher precision measurements of Os isotopes using the Triton TIMS from Thermo Electron. The measurements are made in static mode using 7 Faraday collectors. 70 or more nanograms of Os is loaded onto a Pt filament with barium hydroxide, the latter is an electron emitter that promotes efficient production of Os trioxide. Oxygen is bled into the source at constant pressures. Signal intensities of 120-180 mV 186Os trioxide are generated and measured as negative ions. Oxygen corrections to the raw data are made using the oxygen isotopic composition obtained for 2 ng loads of Re tetroxide measured on the Faraday cups. Multiple runs over the course of 3 years for the same lecture bottle used to bleed in oxygen to the source showed no change in the oxygen isotopic composition. Oxygen corrections are followed by instrumental mass fractionation corrections using 189/188, 192/189, or 192/188 using the exponential law. Both the internal and external precision for standard and unknown data are best when using 192/188, by a factor of 1.4 over 189/188, and 1.8 over 192/189. Replicate runs on 100 ng standard loads of a single filament shows no change in corrected values within external precision for all Os isotopic ratios over a wide range of fractionation, confirming adherence to the exponential law during emission. 39 runs for a standard solution gave +/-14 ppm (2 sigma) on the

  2. Osmium(IV) complexes with 1H- and 2H-indazoles: tautomer identity versus spectroscopic properties and antiproliferative activity.

    PubMed

    Büchel, Gabriel E; Stepanenko, Iryna N; Hejl, Michaela; Jakupec, Michael A; Keppler, Bernhard K; Heffeter, Petra; Berger, Walter; Arion, Vladimir B

    2012-08-01

    A one-pot synthesis of osmium(IV) complexes with two different tautomers of indazole, 1H-indazole and 2H-indazole, namely (H(2)ind)[Os(IV)Cl(5)(2H-ind)] (1) and (H(2)ind)[Os(IV)Cl(5)(1H-ind)] (2) is reported. Both compounds have been comprehensively characterized by NMR spectroscopy, ESI (electrospray ionization) mass spectrometry, electronic absorption spectroscopy, IR spectroscopy, cyclic voltammetry and tested for antiproliferative activity in vitro in three human cancer cell lines, CH1 (ovarian carcinoma), A549 (non-small cell lung cancer) and SW480 (colon carcinoma), as well as in vivo in a Hep3B SCID mouse xeno-transplantation model. 2H-Indazole tautomer stabilization in 1 has been confirmed by X-ray diffraction.

  3. Transmission electron microscopy staining methods for the cortex of human hair: a modified osmium method and comparison with other stains.

    PubMed

    Harland, D P; Vernon, J A; Walls, R J; Woods, J L

    2011-08-01

    For wool, superior staining of a wide range of ultrastructural components is achieved by en bloc treatment of fibres with a chemical reductant followed by osmium tetroxide. For human scalp hair, although staining quality is similar, the penetration of reagents is poor, resulting in large parts of the fibre cortex remaining unstained. Here we describe a modification to the reduction-osmication method in which reagents penetrate through a cut fibre end, allowing visualization of a wide range of features across the cortex. We compare the staining quality, artefacts and range of structure rendered visible using transmission electron microscopy for en bloc reduction-osmication to other staining alternatives including en bloc silver nitrate and section stains based on uranyl acetate and lead citrate, phosphotungstic acid, potassium permanganate, ammoniacal silver nitrate and some combinations of these stains. The effects of hair-care treatments are briefly examined.

  4. Structural Characterization of Semen Coagulum-Derived SEM1(86–107) Amyloid Fibrils That Enhance HIV-1 Infection

    PubMed Central

    2015-01-01

    SEM1(86–107) is a 22-residue peptide corresponding to residues 86–107 in the semenogelin I protein. SEM1(86–107) is an abundant component of freshly liquefied semen and forms amyloid fibrils capable of enhancing HIV infection. To probe the factors affecting fibril formation and gain a better understanding of how differences in pH between semen and vaginal fluid affect fibril stability, this study determined the effect of pH on SEM1(86–107) fibril formation and dissociation. The SEM1(86–107) fibril structure (i.e., residues that comprise the fibrillar core) was also probed using hydrogen–deuterium exchange mass spectrometry (HDXMS) and hydroxyl radical-mediated protein modification. The average percent exposure to hydroxyl radical-mediated modification in the SEM1(86–107) fibrils was determined without requiring tandem mass spectrometry spectral acquisition or complete separation of modified peptides. It was found that the residue exposures calculated from HDXMS and hydroxyl radical-mediated modification were similar. These techniques demonstrated that three regions of SEM1(86–107) comprise the amyloid fibril core and that positively charged residues are exposed, suggesting that electrostatic interactions between SEM1(86–107) and HIV or the cell surface may be responsible for mediating HIV infection enhancement by the SEM1(86–107) fibrils. PMID:24811874

  5. 21 CFR 186.1 - Substances added indirectly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... of food-contact surface(s), the functional use(s) of the ingredient, and the level(s) of use. Any use... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Substances added indirectly to human food affirmed as generally recognized as safe (GRAS). 186.1 Section 186.1 Food and Drugs FOOD AND...

  6. 27 CFR 70.186 - Legal effect of certificate of sale of personal property and deed of real property.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 2 2010-04-01 2010-04-01 false Legal effect of certificate of sale of personal property and deed of real property. 70.186 Section 70.186 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY (CONTINUED) PROCEDURES AND PRACTICES PROCEDURE...

  7. 43 CFR 30.186 - Are renunciations that predate the American Indian Probate Reform Act of 2004 valid?

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... American Indian Probate Reform Act of 2004 valid? 30.186 Section 30.186 Public Lands: Interior Office of... renunciations that predate the American Indian Probate Reform Act of 2004 valid? Any renunciation filed and included as part of a probate decision or order issued before the effective date of the American...

  8. 43 CFR 30.186 - Are renunciations that predate the American Indian Probate Reform Act of 2004 valid?

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... American Indian Probate Reform Act of 2004 valid? 30.186 Section 30.186 Public Lands: Interior Office of... renunciations that predate the American Indian Probate Reform Act of 2004 valid? Any renunciation filed and included as part of a probate decision or order issued before the effective date of the American...

  9. TFIIB/SUA7(E202G) is an allele-specific suppressor of TBP1(E186D)

    PubMed Central

    Chew, Boon Shang; Lehming, Norbert

    2007-01-01

    The TBP (TATA-box-binding protein), Tbp1p, plays a vital role in all three classes of transcription by RNA polymerases I–III. A TBP1(E186D) mutation had been described that affected interaction of Tbp1p with TFIIB (transcription factor IIB) and that caused slow-growth, temperature-sensitivity, 3-aminotriazole-sensitivity as well as a gal− phenotype. We used the TBP1(E186D) mutant for suppressor screens, and we isolated TFIIB/SUA7(E202G) as an allele-specific suppressor of all phenotypes caused by the TBP1(E186D) mutation. Our results show that the SUA7(E202G) mutation restored binding of TFIIB to Tbp1(E186D)p. In addition, we observed that Tbp1(E186D)p was expressed at a lower level than wild-type Tbp1p, and that SUA7(E202G) restored the protein level of Tbp1(E186D)p. This suggested that the TBP1(E186D) mutation might have generated its phenotypes by making Tbp1p the limiting factor for activated transcription. DNA microarray analysis indicated that the TBP1(E186D) temperature-sensitivity and slow-growth phenotypes might have been caused by insufficient amounts of Tbp1p for efficient transcription of the rRNA genes by RNA polymerase I. PMID:17680779

  10. Electronic structures of ruthenium and osmium complexes of 9,10-phenanthrenequinone.

    PubMed

    Biswas, Manas Kumar; Patra, Sarat Chandra; Maity, Amarendra Nath; Ke, Shyue-Chu; Adhikary, Nirmal Das; Ghosh, Prasanta

    2012-06-18

    The reaction of 9,10-phenanthrenequinone (PQ) with [M(II)(H)(CO)(X)(PPh(3))(3)] in boiling toluene leads to the homolytic cleavage of the M(II)-H bond, affording the paramagnetic trans-[M(PQ)(PPh(3))(2)(CO)X] (M = Ru, X = Cl, 1; M = Os, X = Br, 3) and cis-[M(PQ)(PPh(3))(2)(CO)X] (M = Ru, X = Cl, 2; M = Os, X = Br, 4) complexes. Single-crystal X-ray structure determinations of 1, 2·toluene, and 4·CH(2)Cl(2), EPR spectra, and density functional theory (DFT) calculations have substantiated that 1-4 are 9,10-phenanthrenesemiquinone radical (PQ(•-)) complexes of ruthenium(II) and osmium(II) and are defined as trans-[Ru(II)(PQ(•-))(PPh(3))(2)(CO)Cl] (1), cis-[Ru(II)(PQ(•-))(PPh(3))(2)(CO)Cl] (2), trans-[Os(II)(PQ(•-))(PPh(3))(2)(CO) Br] (3), and cis-[Os(II)(PQ(•-))(PPh(3))(2)(CO)Br] (4). Two comparatively longer C-O [average lengths: 1, 1.291(3) Å; 2·toluene, 1.281(5) Å; 4·CH(2)Cl(2), 1.300(8) Å] and shorter C-C lengths [1, 1.418(5) Å; 2·toluene, 1.439(6) Å; 4·CH(2)Cl(2), 1.434(9) Å] of the OO chelates are consistent with the presence of a reduced PQ(•-) ligand in 1-4. A minor contribution of the alternate resonance form, trans- or cis-[M(I)(PQ)(PPh(3))(2)(CO)X], of 1-4 has been predicted by the anisotropic X- and Q-band electron paramagnetic resonance spectra of the frozen glasses of the complexes at 25 K and unrestricted DFT calculations on 1, trans-[Ru(PQ)(PMe(3))(2)(CO)Cl] (5), cis-[Ru(PQ)(PMe(3))(2)(CO)Cl] (6), and cis-[Os(PQ)(PMe(3))(2)(CO)Br] (7). However, no thermodynamic equilibria between [M(II)(PQ(•-))(PPh(3))(2)(CO)X] and [M(I)(PQ)(PPh(3))(2)(CO)X] tautomers have been detected. 1-4 undergo one-electron oxidation at -0.06, -0.05, 0.03, and -0.03 V versus a ferrocenium/ferrocene, Fc(+)/Fc, couple because of the formation of PQ complexes as trans-[Ru(II)(PQ)(PPh(3))(2)(CO)Cl](+) (1(+)), cis-[Ru(II)(PQ)(PPh(3))(2)(CO)Cl](+) (2(+)), trans-[Os(II)(PQ)(PPh(3))(2)(CO)Br](+) (3(+)), and cis-[Os(II)(PQ)(PPh(3))(2)(CO)Br](+) (4(+)). The trans

  11. Thermally Activated Site Exchange and Quantum Exchange Coupling Processes in Unsymmetrical Trihydride Osmium Compounds.

    PubMed

    Castillo, Amaya; Barea, Guada; Esteruelas, Miguel A.; Lahoz, Fernando J.; LLedós, Agustí; Maseras, Feliu; Modrego, Javier; Oñate, Enrique; Oro, Luis A.; Ruiz, Natividad; Sola, Eduardo

    1999-04-19

    Reaction of the hexahydride complex OsH(6)(P(i)Pr(3))(2) (1) with pyridine-2-thiol leads to the trihydride derivative OsH(3){kappa-N,kappa-S-(2-Spy)}(P(i)Pr(3))(2) (2). The structure of 2 has been determined by X-ray diffraction. The geometry around the osmium atom can be described as a distorted pentagonal bipyramid with the phosphine ligands occupying axial positions. The equatorial plane contains the pyridine-2-thiolato group, attached through a bite angle of 65.7(1) degrees, and the three hydride ligands. The theoretical structure determination of the model complex OsH(3){kappa-N,kappa-S-(2-Spy)}(PH(3))(2) (2a) reveals that the hydride ligands form a triangle with sides of 1.623, 1.714, and 2.873 Å, respectively. A topological analysis of the electron density of 2a indicates that there is no significant electron density connecting the hydrogen atoms of the OsH(3) unit. In solution, the hydride ligands of 2 undergo two different thermally activated site exchange processes, which involve the central hydride with each hydride ligand situated close to the donor atoms of the chelate group. The activation barriers of both processes are similar. Theoretical calculations suggest that the transition states have a cis-hydride-dihydrogen nature. In addition to the thermally activated exchange processes, complex 2 shows quantum exchange coupling between the central hydride and the one situated close to the sulfur atom of the pyridine-2-thiolato group. The reactions of 1 with L-valine and 2-hydroxypyridine afford OsH(3){kappa-N,kappa-O-OC(O)CH[CH(CH(3))(2)]NH(2)}(P(i)Pr(3))(2) (3) and OsH(3){kappa-N,kappa-O-(2-Opy)}(P(i)Pr(3))(2) (4) respectively, which according to their spectroscopic data have a similar structure to that of 2. In solution, the hydride ligands of 3 and 4 also undergo two different thermally activated site exchange processes. However, they do not show quantum exchange coupling. The tetranuclear complexes [(P(i)Pr(3))(2)H(3)Os(&mgr;-biim)M(TFB)](2) [M = Rh

  12. Proto-Pacific OAE2 osmium isotope records revealed: global correlation and basin dynamics

    NASA Astrophysics Data System (ADS)

    Du Vivier, A.; Selby, D. S.; Takashima, R.; Condon, D. J.; Nishi, H.

    2013-12-01

    Globally the marine realm across the Cenomanian-Turonian boundary interval records the oceanic anoxic event (OAE) 2. This event has been studied using several geochemical proxies at several sites from the proto-Atlantic. In contrast, there are limited studies from the proto-Pacific. We present initial osmium isotope stratigraphy (Osi) from two proto-Pacific sites: the Yezo Group (YG) section, Hokkaido, Japan, and the Great Valley Sequence (GVS), California, USA; to evaluate the Os seawater chemistry of the proto-Pacific with that of the proto-Atlantic. For the YG section the Osi prior to OAE2 are moderately radiogenic and heterogeneous. Synchronous with OAE2 onset the Osi abruptly become unradiogenic and remain homogenous before showing a gradual return to more radiogenic Osi throughout the middle to late OAE2. The Osi profile from the YG is analogous to the record from the Portland #1 core of the Western Interior Seaway (WIS). In contrast, the Osi profile from the GVS is disparate to the YG profile and those of several proto-Atlantic locations. The Osi for the GVS oscillate from radiogenic to unradiogenic values across the OAE2. We suggest the Osi of the GVS was influenced interchangeably by both unradiogenic and radiogenic Os; where radiogenic Osi is associated with weathered evolved continental rocks and unradiogenic Osi is derived from a submarine hydrothermal input associated with the Caribbean Large Igneous Province (CLIP). All proto-Atlantic sections show a synchronous correlation between Osi and δ13Corg excursions. However, this is not the case for the YG. As such we infer that the OAE2 excursion has been misidentified in the δ13Cwood analysis for the YG and thus the onset is ~24 m higher in the section. In order to further facilitate correlation we identified a number of zircon bearing tuff horizons throughout the YG for U-Pb ID-TIMS zircon geochronology. The Osi data and U-Pb age(s) combined, improves the correlation and the identification of the OAE2

  13. Marine osmium isotopic record of cherts across the Triassic-Jurassic boundary: implications for environmental change

    NASA Astrophysics Data System (ADS)

    Suzuki, K.; Kuroda, J.; Hori, R. S.; Ohkouchi, N.; Grocke, D. R.

    2010-12-01

    Attention has long been focused on relationships between massive volcanisms and major environmental change such as large mass extinctions (e.g., Wignall, 2001). The Triassic-Jurassic (T-J) boundary at c.a. 200 Ma has been regarded as one of the five biggest mass extinction events in the Phanerozoic when a substantial proportion of marine and terrestrial species became extinct. This period also marks extensive magmatic activities associated with the emplacement of the Central Atlantic Magmatic Province (CAMP). These magmatic activities are likely to be a possible forcing mechanism for the climatic changes in the T-J transition. However, the mechanism triggering the T-J mass extinction is still under debate, because there are remarkable difficulties in correlating the timing of the widespread CAMP volcanic activity with the environmental events, and in estimating the environmental impact of large-scale igneous activity. Since seawater Os isotopic composition varies in response to change in balance of Os supply from continental, mantle and extraterrestrial sources, Os isotopic record from hydrogenous fraction of marine sediments is useful to reconstruct secular changes in the relative contribution from these sources (Ravizza and Peucker-Ehrenbrink, 2003; Tugeon and Creaser, 2008; Tejada et al., 2009). Such information possibly provides us important constraints on the mechanism of the environmental change and mass extinction. Although Cohen and Coe (2007) have reported Os isotopic records across the T-J boundary from southern England, no data have been reported from the Paleo-Pacific (Panthalassa) pelagic basin that covered approximately half of the Earth’s surface. Here we present a high-resolution isotopic record of osmium extracted from bedded chert successions across the T-J boundary in Kurusu section, central Japan, deposited on a Panthalassa deep basin. Our new dataset show a gradual decrease in seawater 187Os/188Os values through the Rhaetian and subsequent

  14. Coding region variant 186H/R in Exon 4 of APOBEC3G among individuals of Western India.

    PubMed

    Singh, Hariom; Marathe, Shruti; Nain, Sumitra; Nema, Vijay; Angadi, Mansa; Bapat, Shradha; Pawar, Jyoti; Ghate, Manisha; Sahay, Seema; Gangakhedkar, Raman R

    2016-05-01

    The allelic variations in the AIDS restriction genes have been associated with the acquisition of HIV-1 and its progression. The distribution of antiviral gene variants significantly differs between populations. Therefore, we aimed to evaluate the distribution of variant allele of 186H/R in exon4 of APOBEC3G between HIV infected individuals and healthy controls among western Indian.In the present cross-sectional study, we enrolled a total of 153 HIV-infected patients confirmed and 156 unrelated healthy individuals. Polymorphism for 186H/R in exon4 of APOBEC3G gene was genotyped by PCR-RFLP. With the frequency of 186HR heterozygous genotype of APOBEC3G was found to be 13% in healthy controls and none in HIV infected cases. The frequency of 186HH common genotype of APOBEC3G was observed higher in HIV infected individuals compared with healthy controls (100% vs 91.7%). The variant genotype 186RR in APOBEC3G was not found in both the groups. The frequency of 186R allele of APOBEC3G was found 4.16% in healthy controls and nil in HIV-infected cases. The frequency of 186H allele of APOBEC3G was found to be higher in HIV-infected cases compared with healthy controls (100% vs 95.83%). The frequency of 186R allele in exon4 of APOBEC3G was found to be 4.16% in healthy controls. This observation differs from the previous report published from North India stating the absence of 186R allele of APOBEC3G in the North Indian individuals. The variant 186H/R in exon4 of APOBEC3G was neither associated with risk of acquisition of HIV-1 nor its progression.

  15. A simple osmium post-fixation paraffin-embedment technique to identify lipid accumulation in fish liver using medaka (Oryziaslatipes) eggs and eleutheroembryos as lipid rich models.

    PubMed

    Mondon, J A; Howitt, J; Tosiano, M; Kwok, K W H; Hinton, D E

    2011-01-01

    Hepatic lipidosis is a non-specific biomarker of effect from pollution exposure in fish. Fatty liver is often misdiagnosed or overlooked in histological assessments due to the decreasing application of specific fat procedures and stains. For example, ethanol dehydration in standard paraffin processing removes lipids, leaving vacuoles of which the precise nature is unknown. Lipids can be identified using osmium post-fixation in semi-thin resin sections or transmission electron microscopy. However, both are expensive and technically demanding procedures, often not available for routine environmental risk assessment and monitoring programs. The current emphasis to reduce and refine animal toxicity testing, requires refinement of the suite of histopathological techniques currently available to maximize information gained from using fish for toxicity testing and as bio-indicators of environmental quality. This investigation has successfully modified an osmium post-fixation technique to conserve lipids in paraffin-embedded tissues using medaka (Oryzias latipes) eleutheroembryos and eggs (embryos) as lipid rich models.

  16. Electrical Wiring of the Aldehyde Oxidoreductase PaoABC with a Polymer Containing Osmium Redox Centers: Biosensors for Benzaldehyde and GABA

    PubMed Central

    Badalyan, Artavazd; Dierich, Marlen; Stiba, Konstanze; Schwuchow, Viola; Leimkühler, Silke; Wollenberger, Ulla

    2014-01-01

    Biosensors for the detection of benzaldehyde and γ−aminobutyric acid (GABA) are reported using aldehyde oxidoreductase PaoABC from Escherichia coli immobilized in a polymer containing bound low potential osmium redox complexes. The electrically connected enzyme already electrooxidizes benzaldehyde at potentials below −0.15 V (vs. Ag|AgCl, 1 M KCl). The pH-dependence of benzaldehyde oxidation can be strongly influenced by the ionic strength. The effect is similar with the soluble osmium redox complex and therefore indicates a clear electrostatic effect on the bioelectrocatalytic efficiency of PaoABC in the osmium containing redox polymer. At lower ionic strength, the pH-optimum is high and can be switched to low pH-values at high ionic strength. This offers biosensing at high and low pH-values. A “reagentless” biosensor has been formed with enzyme wired onto a screen-printed electrode in a flow cell device. The response time to addition of benzaldehyde is 30 s, and the measuring range is between 10–150 µM and the detection limit of 5 µM (signal to noise ratio 3:1) of benzaldehyde. The relative standard deviation in a series (n = 13) for 200 µM benzaldehyde is 1.9%. For the biosensor, a response to succinic semialdehyde was also identified. Based on this response and the ability to work at high pH a biosensor for GABA is proposed by coimmobilizing GABA-aminotransferase (GABA-T) and PaoABC in the osmium containing redox polymer. PMID:25587431

  17. High-latitude oceanic variability associated with the 18.6-year nodal tide

    NASA Technical Reports Server (NTRS)

    Royer, Thomas C.

    1993-01-01

    Water column temperature variations which indicate that the upper ocean is responding to 18.6-yr tidal forcing are presented. An enhanced high-latitude response to this forcing is predicted by equilibrium tide theory, and it should be most evident at latitudes poleward of about 50 deg. Critical information on regional climate variations might be found in the subsurface waters of the North Pacific and possibly other high-latitude oceans. The 18.6-yr nodal tidal cycle must be considered in circulation models of the ocean and atmosphere that examine time scales of decades or longer. Because the temperature range associated with the cycle is 0.5-1 C, short-term climate and biological populations could be affected.

  18. UV induction of coliphage 186: Prophage induction as an SOS function

    SciTech Connect

    Lamont, I.; Brumby, A.M.; Egan, J.B.

    1989-07-01

    Our results show that UV induction of the 186 prophage depends upon the phage function Tum, with the mutant phenotype of turbid plaques on mitomycin plates and the expression of which is controlled by the host LexA protein. Tum function, encoded near the right-hand end of the coliphage 186 chromosome, is under the control of promoter p95. This promoter is overlapped by a sequence closely related to the consensus sequence of the LexA-binding site. It is proposed that inactivation of LexA after UV irradiation (or by genetic means) leads to prophage induction by permitting expression of Tum which, by unknown means, induces prophage. This mechanism is basically different from that seen with the UV-inducible lambdoid coliphages, which are not regulated by LexA.

  19. Zn1.86Cd0.14(OH)VO4

    PubMed Central

    Đorđević, Tamara; Stojanović, Jovica; Karanović, Ljiljana

    2010-01-01

    The title compound, dizinc cadmium hydroxide tetraoxido­vanadate, Zn1.86Cd0.14(OH)VO4, was prepared under low-temperature hydro­thermal conditions. It is isostructural with Zn2(OH)VO4 and Cu2(OH)VO4. In the crystal structure, chains of edge-sharing [ZnO6] octahedra are inter­connected by VO4 tetra­hedra (site symmetries of both V atoms and their coordination polyhedra are .m.) to form a three-dimensional [Zn(OH)VO4]2− framework with channels occupied by Zn and Zn/Cd cations adopting trigonal–bipyramidal and distorted octa­hedral coordinations, respectively. Zn1.86Cd0.14(OH)VO4 is topologically related to adamite-type phases, and descloizite- and tsumcorite-type structures. PMID:21589202

  20. Photocatalytic performance of nitrogen, osmium co-doped TiO2 for removal of eosin yellow in water under simulated solar radiation.

    PubMed

    Kuvarega, Alex T; Krause, Rui W M; Mamba, Bhekie B

    2013-07-01

    Nitrogen, osmium co-doped TiO2 photocatalysts were prepared by a modified sol-gel method using ammonia as the nitrogen source and osmium tetroxide as the source of osmium. The role of rutile phase OsO2 in enhancing the photocatalytic activity of rutile TiO2 towards the degradation of Eosin Yellow was investigated. The materials were characterised by various techniques that include FTIR, Raman, XRD, SEM, EDS, TEM, TGA and DRUV-Vis. The amorphous, oven dried sample was transformed to the anatase and then the rutile phase with increasing calcination temperature. DRUV-Vis analysis revealed a red shift in absorption with increasing calcination temperature, confirmed by a decrease in the band gap of the material. The photocatalytic activity of N, Os co-doped TiO2 was evaluated using eosin yellow degradation and activity increased with increase in calcination temperature under simulated solar irradiation. The rutile phase of the co-doped TiO2 was found to be more effective in degrading the dye (k(a) = 1.84 x 10(-2) min(-1)) compared to the anatase co-doped phase (k(a) = 9.90 x 10(-3) min(-1)). The enhanced photocatalytic activity was ascribed to the synergistic effects of rutile TiO2 and rutile OsO2 in the N, Os co-doped TiO2.

  1. Rhenium and osmium isotopes in black shales and Ni-Mo-PGE-rich sulfide layers, Yukon Territory, Canada, and Hunan and Guizhou provinces, China

    USGS Publications Warehouse

    Horan, M.F.; Morgan, J.W.; Grauch, R.I.; Coveney, R.M.; Murowchick, J.B.; Hulbert, L.J.

    1994-01-01

    Rhenium and osmium abundances and osmium isotopic compositions were determined by negative thermal ionization mass spectrometry for samples of Devonian black shale and an associated Ni-enriched sulfide layer from the Yukon Territory, Canada. The same composition information was also obtained for samples of early Cambrian Ni-Mo-rich sulfide layers hosted in black shale in Guizhou and Hunan provinces, China. This study was undertaken to constrain the origin of the PGE enrichment in the sulfide layers. Samples of the Ni sulfide layer from the Yukon Territory are highly enriched in Re, Os, and other PGE, with distinctly higher Re/192Os but similar Pt/Re, compared to the black shale host. Re-Os isotopic data of the black shale and the sulfide layer are approximately isochronous, and the data plot close to reference isochrons which bracket the depositional age of the enclosing shales. Samples of the Chinese sulfide layers are also highly enriched in Re, Os, and the other PGE. Re/192Os are lower than in the Yukon sulfide layer. Re-Os isotopic data for the sulfide layers lie near a reference isochron with an age of 560 Ma, similar to the depositional age of the black shale host. The osmium isotopic data suggest that Re and PGE enrichment of the brecciated sulfide layers in both the Yukon Territory and in southern China may have occurred near the time of sediment deposition or during early diagenesis, during the middle to late Devonian and early Cambrian, respectively. ?? 1994.

  2. High-latitude oceanic variability associated with the 18.6-year nodal tide

    NASA Astrophysics Data System (ADS)

    Royer, Thomas C.

    1993-03-01

    Ocean temperatures in the upper 250 m in the northern North Pacific (60°N, 149°W) increased by more than 1°C from 1972 to 1986 but are now decreasing. Subsurface temperature anomalies are well correlated (˜0.58) with the air temperature anomalies at Sitka, Alaska; hence the coastal air temperatures can be used as a proxy data set to extend the ocean temperature time series back to 1828. Up to 30% of the low-frequency variance can be accounted for with the 18.6-year nodal signal. Additionally, spectral analysis of these air temperature variations indicates a significant low-frequency peak in the range of the 18.6-year signal. Similar low-frequency signals have been reported for Hudson Bay air temperatures since 1700, for sea surface temperatures in the North Atlantic from 1876 to 1939, and for sea level in the high-latitude southern hemisphere. The water column temperature variations presented here are the first evidence that the upper ocean is responding to this very long period tidal forcing. An enhanced high-latitude response to the 18.6-year forcing is predicted by equilibrium tide theory, and it should be most evident at latitudes poleward of about 50°. These low-frequency ocean-atmosphere variations must be considered in high-latitude assessments of global climate change, since they are of the same magnitude as many of the predicted global changes.

  3. Evaluation of thrombocytopenia in patients treated with rhenium-186-HEDP: Guidelines for individual dosage recommendations

    SciTech Connect

    Klerk, J.M.H. de; Schip, A.D. van het; Zonnenberg, B.A

    1994-09-01

    A potential limitation of rhenium-186-1,1-hydroxyethylidene diphosphonate ({sup 186}Re-HEDP) therapy in patients with painful bone metastases is thrombocytopenia. Given the palliative character of this therapy, it is essential to be able to predict the degree of thrombocytopenia before therapy. Thus far, 39 prostatic cancer patients with multiple painful bone metastases were treated. Twenty-one patients underwent the therapy twice, resulting in 60 therapies. From the pre-therapy {sup 99m}Tc-HDP scintigram, the bone scan index (BSI) was determined as an index of the extent of bone involvement. The administered activity ranged from 1104 to 3479 MBq {sup 186}Re-HEDP. The platelet count was lowest 4 wk following therapy. From this value and the pretreatment level, the percentage decrease in the platelet count was determined (47%{+-}19%, range 14%-89%). The BSI ranged from 8 to 93. Regression analysis showed a functional relation (R = 0.78; p < 0.001) of the percentage of platelet decrease with BSI and administered activity normalized to standard body surface area. Using this relation, it is possible to predict thrombocytopenia by pretreatment bone scintigraphy and to adjust the dosage to each patient to avoid unacceptable toxicity. 27 refs., 4 figs., 1 tab.

  4. Rhenium-186 liposomes as convection-enhanced nanoparticle brachytherapy for treatment of glioblastoma.

    PubMed

    Phillips, William T; Goins, Beth; Bao, Ande; Vargas, Daniel; Guttierez, Juan E; Trevino, Abram; Miller, Jessica R; Henry, James; Zuniga, Richard; Vecil, Giacomo; Brenner, Andrew J

    2012-04-01

    Although external beam radiation is an essential component to the current standard treatment of primary brain tumors, its application is limited by toxicity at doses more than 80 Gy. Recent studies have suggested that brachytherapy with liposomally encapsulated radionuclides may be of benefit, and we have reported methods to markedly increase the specific activity of rhenium-186 ((186)Re)-liposomes. To better characterize the potential delivery, toxicity, and efficacy of the highly specific activity of (186)Re-liposomes, we evaluated their intracranial application by convection-enhanced delivery in an orthotopic U87 glioma rat model. After establishing an optimal volume of 25 µL, we observed focal activity confined to the site of injection over a 96-hour period. Doses of up to 1850 Gy were administered without overt clinical or microscopic evidence of toxicity. Animals treated with (186)Re-liposomes had a median survival of 126 days (95% confidence interval [CI], 78.4-173 days), compared with 49 days (95% CI, 44-53 days) for controls. Log-rank analysis between these 2 groups was highly significant (P = .0013) and was even higher when 100 Gy was used as a cutoff (P < .0001). Noninvasive luciferase imaging as a surrogate for tumor volume showed a statistically significant separation in bioluminescence by 11 days after 100 Gy or less treatment between the experimental group and the control animals (χ(2)[1, N= 19] = 4.8; P = .029). MRI also supported this difference in tumor size. Duplication of tumor volume differences and survival benefit was possible in a more invasive U251 orthotopic model, with clear separation in bioluminescence at 6 days after treatment (χ(2)[1, N= 9] = 4.7; P = .029); median survival in treated animals was not reached at 120 days because lack of mortality, and log-rank analysis of survival was highly significant (P = .0057). Analysis of tumors by histology revealed minimal areas of necrosis and gliosis. These results support the potential

  5. Linking microsomal prostaglandin E Synthase-1/PGE-2 pathway with miR-15a and −186 expression: Novel mechanism of VEGF modulation in prostate cancer

    PubMed Central

    Finetti, Federica; Nesi, Gabriella; Villari, Donata; Hanaka, Hiromi; Radmark, Olof; Giachetti, Antonio; Ziche, Marina

    2016-01-01

    Prostaglandin E-2 (PGE-2) promotes tumor angiogenesis via paracrine secretion of pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF). Since miRNAs regulate several cell processes, including angiogenesis, we sought to determine whether they would influence PGE-2-induced VEGF. We compared DU145 and PC3 prostate cancer cells bearing the mPGES-1 enzyme (mPGES-1+/+) and producing PGE-2, with those in which the enzyme was silenced or deleted (mPGES-1−/−). We demonstrated that mPGES-1/PGE-2 signaling decreased Dicer expression and miRNA biogenesis. Genome-wide sequencing of miRNAs revealed that miR-15a and miR-186, associated with expression of VEGF and hypoxia inducible factor-1α (HIF-1α), were down-regulated in mPGES-1+/+ cells. As a consequence, mPGES-1+/+ tumor cells expressed high levels of VEGF and HIF-1α, induced endothelial cells activation and formed highly vascularized tumors. Mir-186 mimic inhibited VEGF expression in mPGES-1+/+ tumor xenografts and reduced tumor growth. In human prostate cancer specimens, mPGES-1 was over-expressed in tumors with high Gleason score, elevated expression of VEGF and HIF-1α, high microvessel density and decreased expression of Dicer, miR15a and miR-186. Thus, clear evidence for regulating miRNA processing and VEGF output by intrinsic PGE-2 production provides a means to distinguish between aggressive and indolent prostate tumors and suggests a potential target for controlling tumor progression. PMID:27322147

  6. Linking microsomal prostaglandin E Synthase-1/PGE-2 pathway with miR-15a and -186 expression: Novel mechanism of VEGF modulation in prostate cancer.

    PubMed

    Terzuoli, Erika; Donnini, Sandra; Finetti, Federica; Nesi, Gabriella; Villari, Donata; Hanaka, Hiromi; Radmark, Olof; Giachetti, Antonio; Ziche, Marina

    2016-07-12

    Prostaglandin E-2 (PGE-2) promotes tumor angiogenesis via paracrine secretion of pro-angiogenic growth factors, such as vascular endothelial growth factor (VEGF). Since miRNAs regulate several cell processes, including angiogenesis, we sought to determine whether they would influence PGE-2-induced VEGF. We compared DU145 and PC3 prostate cancer cells bearing the mPGES-1 enzyme (mPGES-1+/+) and producing PGE-2, with those in which the enzyme was silenced or deleted (mPGES-1-/-). We demonstrated that mPGES-1/PGE-2 signaling decreased Dicer expression and miRNA biogenesis. Genome-wide sequencing of miRNAs revealed that miR-15a and miR-186, associated with expression of VEGF and hypoxia inducible factor-1α (HIF-1α), were down-regulated in mPGES-1+/+ cells. As a consequence, mPGES-1+/+ tumor cells expressed high levels of VEGF and HIF-1α, induced endothelial cells activation and formed highly vascularized tumors. Mir-186 mimic inhibited VEGF expression in mPGES-1+/+ tumor xenografts and reduced tumor growth. In human prostate cancer specimens, mPGES-1 was over-expressed in tumors with high Gleason score, elevated expression of VEGF and HIF-1α, high microvessel density and decreased expression of Dicer, miR15a and miR-186. Thus, clear evidence for regulating miRNA processing and VEGF output by intrinsic PGE-2 production provides a means to distinguish between aggressive and indolent prostate tumors and suggests a potential target for controlling tumor progression.

  7. Non-carrier-added 186, 188Re labeled 17a-ethynylestradiol : a potential breast cancer imaging and therapy agent

    SciTech Connect

    Fassbender, M. E.; Phillips, Dennis R.; Peterson, E. J.; Ott, K. C.; Arterburn, J. B.

    2001-01-01

    Receptor-targeted radiopharmaceuticals constitute potential agents for the diagnosis and therapy of cancer. Breast cancer is the most prevalent form of diagnosed cancer in women in the United States, and it accounts for the second highest number of cases of cancer fatalities (1). In Approximately two-thirds of the breast tumors, estrogen and progesterone steroid hormone receptors can be found. Such tumors can often be treated successfully with anti-estrogen hormone therapy (2). Hence, the ability to determine the estrogen receptor (ER) contend of the breast tumor is essential for making the most appropriate choice of treatment for the patient. Along with this diagnostic aspect, steroid-based radiopharmaceuticals with high specific activity offer an encouraging prospect for therapeutic applications: {sup 186,188}Re labeled steroids binding to receptors expressed by cancer cells appear to be potential agents for the irradiation of small to medium-sized tumors. {sup 186}Re has been regarded as an ideal radionuclide for radiotherapy due to its appropriate half-live of 90 h and {beta}-energy of 1.07 MeV. Moreover, the {gamma}-emission of 137 keV that allows in vivo imaging while in therapy is an additional bonus. {sup 188}Re is obtained from a {sup 188}W/{sup 188}Re radionuclide generator system, representing an advantage for availability at radiopharmacy laboratory by daily elution. In addition, {sup 188}Re emits high energy beta particles with an average energy of 769 keV, and the emission of the 155 keV allows simultaneous imaging for biodistribution evaluation in vivo. In order to avoid competitive saturation of the binding sites of the ligand receptor, Re labeled steroids with high specific activity are required, and the removal of all excess unlabeled ligands is mandatory. {sup 188}Re is eluted from a {sup 188}W/{sup 188}Re generator produced and provided by Oak Ridge National Laboratory (3). This paper outlines the solid phase-supported preparation of an n

  8. 76 FR 22160 - Fifty-Fourth Meeting: RTCA Special Committee 186: Automatic Dependent Surveillance-Broadcast (ADS-B)

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-04-20

    ... Meeting New Business Other Business Review Action Items/Work Programs Adjourn Plenary Attendance is open..., RTCA Paper No. 035-11/SC186-307 FAA Surveillance and Broadcast Services (SBS) Program Status...

  9. cis-1,2-Aminohydroxylation of Alkenes Involving a Catalytic Cycle of Osmium(III) and Osmium(V) Centers: Os(V)(O)(NHTs) Active Oxidant with a Macrocyclic Tetradentate Ligand.

    PubMed

    Sugimoto, Hideki; Mikami, Akine; Kai, Kenichiro; Sajith, P K; Shiota, Yoshihito; Yoshizawa, Kazunari; Asano, Kaori; Suzuki, Takeyuki; Itoh, Shinobu

    2015-07-20

    Catalytic activity of [Os(III)(OH)(H2O)(L-N4Me2)](PF6)2 (1: L-N4Me2 = N,N'-dimethyl-2,11-diaza-[3,3](2,6)pyridinophane) in 1,2-cis-aminohydroxylation of alkenes with sodium N-chloro-4-methylbenzenesulfonamide (chloramine-T) is explored. Simple alkenes as well as those containing several types of substituents are converted to the corresponding 1,2-aminoalcohols in modest to high yields. The aminoalcohol products have exclusively cis conformation with respect to the introduced -OH and -NHTs groups. The spectroscopic measurements including cold mass spectroscopic study of the reaction product of complex 1 and chloromine-T as well as density functional theory (DFT) calculations indicate that an oxido-aminato-osmium(V) species [Os(V)(O)(NHTs)(L-N4Me2)](PF6)2 (2) is an active oxidant for the aminohydroxylation. The DFT calculations further indicate that the reaction involves a [3 + 2] cycloaddition between 2 and alkene, and the regioselectivity in the aminohydroxylation of unsymmetrical alkenes is determined by the orientation that bears less steric hindrance from the tosylamino group, which leads to the energetically more preferred product isomer.

  10. Radiosynoviorthesis in hemophilic joints with yttrium-90 citrate and rhenium-186 sulfide and long term results.

    PubMed

    Teyssler, Petr; Taborska, Katerina; Kolostova, Katarina; Bobek, Vladimir

    2013-01-01

    Repeated bleeding in the joint cavities is the most annoying symptom and often has disabling effects in patients with hemophilia (PWH). Our aim was to study the effect of radiosynovectomy (RSO) with beta particle-emitting radiocolloids in the treatment of hemorhagic arthropathy. We have treated 22 joints from 18 patients with hemophilia A, from April 2008 to February 2012, 5 knees, 11 elbows and 6 ankles. Joints were divided into two Groups, those treated with yttrium-90-citrate ((90)Y-C) (5 knees, 2 of them twice)-Group I and those with rhenium-186-sulfide ((186)Re-S) (11 elbows, 1 of them treated twice and 6 ankles)-Group II. A total of 25 treatments. Follow-up period was 3 months, 1 year and 3 years. Results showed a favourable subjective and a better objective result in all 5 joints of Group I and in 15/17 joints of Group II, respectively. Follow-up after 3 months showed significant improvement in Hemophilia Join Health Score (HJHS) after 20 treatments and steady score after 5 treatments. After 1 year, 19 treated joints had improved for the first time, 3 remained steady and 3 were not examined. After 3 years, 9 treated joints were HJHS steady, while 16 were not examined. One year after treatment, 13/14 joints of patients, aged 6-23 years showed better HJHS score, while 9/11 joints of patients aged 26-51 years, showed better HJHS. Synovial membrane thickness as measured by MRI in 8 joints, before and 3 months after treatment was not related to prognosis. In conclusion, in a small group of hemophilic patients with hemorrhagic arthropathy treated with (90)Y-C and with (186)Re-S, our study showed good results irrespective of age in 22/25 treatments after 3 months or 1 year. The thickness of synovial membrane in the 8 joints studied was not related to prognosis.

  11. Detection of 18.6 year nodal induced drought in the Patagonian Andes

    NASA Astrophysics Data System (ADS)

    Currie, Robert G.

    1983-11-01

    Analysis of tree-ring chronologies from the Patagonian Andes yields evidence for the 18.6 yr lunar nodal term in drought/flood. The mean discrepancy between epochs of drought/flood and the nodal tide since AD 1600 is 0.7 ± 2.2 yr, but the polarity of the signal is apparently bimodal. From nodal epoch 1750.0 through 1898.9 drought and tide were in phase, whereas prior to 1750.0 and subsequent to 1898.9 drought and tide were out of phase. There is evidence also for the solar cycle drought signal in the data.

  12. On bistable phasing of 18.6 year nodal induced flood in India

    NASA Astrophysics Data System (ADS)

    Currie, Robert G.

    1984-01-01

    In agreement with Campbell (1983), Flood Area Indices (FAI) for India are interpreted as being modulated by tidal forcing at the 18.6 yr lunar nodal period. There is evidence maximum flood was approximately out of phase with nodal epoch 1898.9 whereas at epochs 1917.5, 1936,1, 1954.7, and 1973.3 maximum flood was approximately in phase. This interpretation implies that India should be experiencing widespread dryness in an interval ±2 to 3 years centered at mid-epoch 1982.6.

  13. Physical properties of metallic antiferromagneticCaCo1.86As2 single crystals

    SciTech Connect

    Anand, V. K.; Dhaka, Rajendra S.; Lee, Yongbin; Harmon, Bruce N.; Kaminski, Adam; Johnston, David C.

    2014-06-01

    X-ray powder diffraction (XRD), magnetic susceptibility χ, isothermal magnetization M, heat capacity Cp, and in-plane electrical resistivity ρ measurements as a function of temperature T and magnetic field H are presented for CaCo1.86As2 single crystals. The electronic structure is probed by angle-resolved photoemission spectroscopy (ARPES) measurements of CaCo1.86As2 and by full-potential linearized augmented-plane-wave calculations for the supercell Ca8Co15As16 (CaCo1.88As2). Our XRD crystal structure refinement is consistent with the previous combined refinement of x-ray and neutron powder diffraction data showing a collapsed-tetragonal ThCr2Si2-type structure with 7(1)% vacancies on the Co sites corresponding to the composition CaCo1.86As2 [D. G. Quirinale et al., Phys. Rev. B 88, 174420 (2013)]. The anisotropic χ(T) data are consistent with the magnetic neutron diffraction data of Quirianale et al. that demonstrate the presence of A-type collinear antiferromagnetic order below the Néel temperature TN=52(1) K with the easy axis being the tetragonal c axis. However, no clear evidence from the ρ(T) and Cp(T) data for a magnetic transition at TN is observed. A metallic ground state is demonstrated from the band calculations and the ρ(T), Cp(T), and ARPES data, and spin-polarized calculations indicate a competition between the A-type AFM and FM ground states. The Cp(T) data exhibit a large Sommerfield electronic coefficient reflecting a large density of states at the Fermi energy D(EF) that is enhanced compared with the band structure calculation where the bare D(EF) arises from Co 3d bands. At 1.8 K, the M(H) data for H∥c exhibit a well-defined first-order spin-flop transition at an applied field of 3.5 T. The small ordered moment of ≈0.3μB/Co obtained from the M(H) data at low T, the large exchange enhancement of χ and the lack of a self-consistent interpretation of the χ(T) and M(H,T) data in terms of a local moment Heisenberg model together

  14. A novel copper(II) coordination at His186 in full-length murine prion protein

    SciTech Connect

    Watanabe, Yasuko; Hiraoka, Wakako; Igarashi, Manabu; Ito, Kimihito; Shimoyama, Yuhei; Horiuchi, Motohiro; Yamamori, Tohru; Yasui, Hironobu; Kuwabara, Mikinori; Inagaki, Fuyuhiko; Inanami, Osamu

    2010-04-09

    To explore Cu(II) ion coordination by His{sup 186} in the C-terminal domain of full-length prion protein (moPrP), we utilized the magnetic dipolar interaction between a paramagnetic metal, Cu(II) ion, and a spin probe introduced in the neighborhood of the postulated binding site by the spin labeling technique (SDSL technique). Six moPrP mutants, moPrP(D143C), moPrP(Y148C), moPrP(E151C), moPrP(Y156C), moPrP(T189C), and moPrP(Y156C,H186A), were reacted with a methane thiosulfonate spin probe and a nitroxide residue (R1) was created in the binding site of each one. Line broadening of the ESR spectra was induced in the presence of Cu(II) ions in moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) but not moPrP(D143R1). This line broadening indicated the presence of electron-electron dipolar interaction between Cu(II) and the nitroxide spin probe, suggesting that each interspin distance was within 20 A. The interspin distance ranges between Cu(II) and the spin probes of moPrP(Y148R1), moPrP(Y151R1), moPrP(Y156R1), and moPrP(T189R1) were estimated to be 12.1 A, 18.1 A, 10.7 A, and 8.4 A, respectively. In moPrP(Y156R1,H186A), line broadening between Cu(II) and the spin probe was not observed. These results suggest that a novel Cu(II) binding site is involved in His186 in the Helix2 region of the C-terminal domain of moPrP{sup C}.

  15. Proposal of a neotype strain (A1-86) for Eubacterium rectale. Request for an opinion.

    PubMed

    Duncan, Sylvia H; Flint, Harry J

    2008-07-01

    Eubacterium rectale is one of the most abundant bacterial species recovered from human faeces. E. rectale (Hauduroy et al. 1937) appears in the 'List of Bacterial Names with Standing in Nomenclature', but it is noted that the originally proposed type strain, VPI 0989(T), has been lost and its possible replacement by another strain (VPI 0990) from the same faecal sample has never been formally proposed. It is therefore proposed that strain A1-86 (=DSM 17629=NCIMB 14373), isolated from human adult faeces, be formally recognized as the neotype strain of Eubacterium rectale.

  16. Discovery and Classification of the z=1.86 SLSNe: DES15E2mlf

    NASA Astrophysics Data System (ADS)

    Pan, Y.-C.; Foley, R. J.; Galbany, L.; Gonzalez-Gaitan, S.; Forster, F.; Hamuy, M.; Prieto, J. L.; Yuan, F.; Tucker, B. E.; Lidman, C.; Martini, P.; Gshwend, Julia; Moller, A.; Zhang, B.; Desai, S.; Paech, K.; Smith, R. C.; Schubnell, M.; Kessler, R.; Lasker, J.; Scolnic, D.; Brout, D. J.; Gladney, L.; Sako, M.; Wolf, R. C.; Brown, P. J.; Krisciunas, K.; Suntzeff, N.; Nichol, R.; Papadopoulos, A.; Childress, M.; D'Andrea, C.; Prajs, S.; Smith, M.; Sullivan, M.; Maartens, R.; Gupta, R.; Kovacs, E.; Kuhlmann, S.; Spinka, H.; Ahn, E.; Finley, D. A.; Frieman, J.; Marriner, J.; Wester, W.; Aldering, G.; Kim, A. G.; Thomas, R. C.; Barbary, K.; Bloom, J. S.; Goldstein, D.; Nugent, P.; Perlmutter, S.; Casas, R.; Castander, F. J.

    2015-12-01

    We report the spectroscopic classification of DES15E2mlf as a superluminous supernova (SLSN) discovered by the Dark Energy Survey (ATEL #4668). DES15E2mlf was discovered on 7 November 2015 at R.A. = 00:41:33.40, Decl = -43:27:17.2 with r = 24.1 mag. We obtained spectra using GMOS on Gemini-South (520-990nm) on 06 December 2015 which indicated a redshift of z = 1.86 from Mg II 2800 absorption.

  17. God's punishment and public goods : A test of the supernatural punishment hypothesis in 186 world cultures.

    PubMed

    Johnson, Dominic D P

    2005-12-01

    Cooperation towards public goods relies on credible threats of punishment to deter cheats. However, punishing is costly, so it remains unclear who incurred the costs of enforcement in our evolutionary past. Theoretical work suggests that human cooperation may be promoted if people believe in supernatural punishment for moral transgressions. This theory is supported by new work in cognitive psychology and by anecdotal ethnographic evidence, but formal quantitative tests remain to be done. Using data from 186 societies around the globe, I test whether the likelihood of supernatural punishment-indexed by the importance of moralizing "high gods"-is associated with cooperation.

  18. Description of 0.186-scale model of high-speed duct of national transonic facility

    NASA Technical Reports Server (NTRS)

    Gentry, C. L., Jr.; Igoe, W. B.; Fuller, D. E.

    1981-01-01

    The National Transonic Facility (NTF) is a pressurized cryogenic wind tunnel with a 2.5 m square test section. A 0.186-scale model of the NTF was used to simulate the aerodynamic performance of the components of the high-speed duct of the NTF. These components consist of a wide-angle diffuser, settling chamber, contraction section, test section, model support section, and high-speed diffuser. The geometry of the model tunnel, referred to as the diffuser flow apparatus is described, and some of its operating characteristics are presented.

  19. Mediated glucose enzyme electrodes by cross-linking films of osmium redox complexes and glucose oxidase on electrodes.

    PubMed

    Ó Conghaile, Peter; Kamireddy, Sirisha; MacAodha, Domhnall; Kavanagh, Paul; Leech, Dónal

    2013-04-01

    Here, we report on a novel, versatile approach for the preparation of mediated enzyme electrodes, demonstrated using cross-linked films of glucose oxidase and a range of functionalised osmium complexes on graphite electrodes. Response of enzyme electrodes are optimised by evaluation of glucose response as a function of variation in ratios of [Os(2,2'-bipyridine)2(4-aminomethyl pyridine)Cl](+) redox mediator, polyallylamine support and glucose oxidase enzyme cross-linked using a di-epoxide reagent in films on graphite. Lowering of the redox potential required to mediate glucose oxidation is achieved by synthesis of complexes using (4,4'-dimethyl-2,2'-bipyridine) or (4,4'-dimethoxy-2,2'-bipyridine) as a ligand instead of (2,2'-bipyridine). Enzyme electrodes prepared using the complexes based on dimethoxy- or dimethyl-substituted bipyridines provide glucose oxidation current densities of 30 and 70 μA cm(-2) at 0.2 and 0.35 V applied potential compared to 120 μA cm(-2) at 0.45 V for the initial enzyme electrode, under pseudo-physiological conditions in 5 mM glucose, with stability of signals proving inadequate for long-term operation. Current output and stability may be improved by selection of alternate anchoring and cross-linking methodology, to provide enzyme electrodes capable for application to long-term glucose biosensors and anodes in enzymatic fuel cells.

  20. Matrix infrared spectroscopic and computational studies on the reactions of osmium and iron atoms with carbon monoxide and dinitrogen mixtures.

    PubMed

    Lu, Zhang-Hui; Xu, Qiang

    2011-10-06

    Reactions of laser-ablated osmium and iron atoms with CO and N(2) mixtures in excess neon have been investigated using matrix isolation infrared spectroscopy. The (NN)(x)MCO (M = Os, Fe; x = 1, 2) complexes are formed as reaction products during sample deposition and on annealing. These reaction products are characterized on the basis of the results of isotopic substitution, mixed isotopic splitting patterns, stepwise annealing, broad-band irradiation, and change of reagent concentration and laser energy. Density functional theory calculations have been performed on these products. Overall agreement between the experimental and calculated results supports the identification of these species from the matrix infrared spectra. The bonding characteristics and reaction mechanisms have been discussed. The M-C bonds are stronger than the M-N bonds in the same molecules. The formation of metal carbonyl dinitrogen complexes from the addition of CO to metal dinitrogen complexes is found to be more energetically favorable than that from the reactions of N(2) with metal carbonyls.

  1. Evaluation of performance and stability of biocatalytic redox films constructed with different copper oxygenases and osmium-based redox polymers.

    PubMed

    Jenkins, Peter A; Boland, Susan; Kavanagh, Paul; Leech, Dónal

    2009-09-01

    We are interested in investigating the applications of biocatalytic mediated reduction of oxygen by oxygenases in films on electrode surfaces, as such reactions can form the basis for biosensors or biocatalytic fuel cell development. Here we present approaches aimed at improving the stability and signal output of such films. These include selection of oxygen reducing biocatalysts which are active under physiological conditions and development of redox mediators which offer the opportunity to tailor the mediator to each enzyme. It was found that for each enzyme Melanocarpus albomyces laccase (MaL), Trametes hirsutus laccase (ThL) or bilirubin oxidase (MvBOD) it was the biocatalytic films mediated by Os(2,2'-bipyridine)(2)Cl.PVI that not only generated the highest current densities compared to Os(4,4'-dimethyl-2,2'-bipyridine)(2)Cl.PVI and Os(4,4'-dichloro-2,2'-bipyridine)(2)Cl.PVI, but also proved to be the most stable over 48 h. Under physiological conditions electrodes constructed from MvBOD generated the highest initial current densities for each of the osmium redox polymers, however these films proved to be the least stable over 48 h. Stability could be improved using surface pre-treatment.

  2. Synthesis, structure, spectroscopic properties, and antiproliferative activity in vitro of novel osmium(III) complexes with azole heterocycles.

    PubMed

    Stepanenko, Iryna N; Krokhin, Artem A; John, Roland O; Roller, Alexander; Arion, Vladimir B; Jakupec, Michael A; Keppler, Bernhard K

    2008-08-18

    Reactions of (H 2azole) 2[OsCl 6], where Hazole = pyrazole, Hpz, ( 1), indazole, Hind, ( 2), imidazole, Him, ( 3) and benzimidazole, Hbzim, ( 4) with the corresponding azole heterocycle in 1:4 molar ratio in boiling isoamyl alcohol or hexanol-1 afforded novel water-soluble osmium(III) complexes of the type trans-[OsCl 2(Hazole) 4]Cl, where Hazole = Hpz ( 5a), Hind ( 6a), Him ( 7a), and Hbzim ( 9a) in 50-70% ( 5a, 7a, 9a) and 5% ( 6a) yields. The synthesis of 7a was accompanied by a concurrent reaction which led to minor formation (<4%) of cis-[OsCl 2(Him) 4]Cl ( 8). The complexes were characterized by elemental analysis, IR spectroscopy, UV-vis spectroscopy, ESI mass spectrometry, cyclic voltammetry, and X-ray crystallography. 5a, 7a, and 9a were found to possess remarkable antiproliferative activity in vitro against A549 (non-small cell lung carcinoma), CH1 (ovarian carcinoma), and SW480 (colon carcinoma) cells, which was compared with that of related ruthenium compounds trans-[RuCl 2(Hazole) 4]Cl, where Hazole = Hpz (5b), Hind (6b), Him (7b), and Hbzim (9b).

  3. High-resolution spectroscopy and structure of osmium tetroxide. A benchmark study on 192OsO4.

    PubMed

    Louviot, Maud; Boudon, Vincent; Manceron, Laurent; Roy, Pascale; Bermejo, Dionisio; Martínez, Raúl Z

    2012-10-01

    Osmium tetroxide (OsO(4)) is a heavy tetrahedral molecule that constitutes a benchmark for quantum chemistry calculations. Its favorable spin statistics (due to the zero nuclear spin of oxygen atoms) is such that only A(1) and A(2) (T(d) symmetry) rovibrational levels are allowed, leading to a dense but quite easily resolvable spectrum. We reinvestigate here the ν(1)/ν(3) stretching fundamental (940-980 cm(-1)) dyad region and perform new assignments and effective Hamiltonian parameter fits for the main isotopologue ((192)OsO(4)). We also investigate the ν(2)/ν(4) bending fundamental dyad (300-360 cm(-1)) for the first time and perform a preliminary analysis. New experimental data have been obtained at 0.001 cm(-1) resolution using an isotopically pure (192)OsO(4) sample and the Synchrotron SOLEIL light source. Assignments and analyses were performed using SPVIEW and XTDS software, respectively. We provide precise effective Hamiltonian parameters, including the band centers for all of the fundamental levels and rotational constants for the ground state and for all four fundamental levels. We discuss isotopic shifts, estimate the equilibrium rotational constant B(e), and derive a precise value for the equilibrium bond length r(e)(Os-O) = 1.70919(16) Å. We also performed experiments to measure for the first time the IR integrated intensities for the ν(2)/ν(4) bending fundamental dyad. These new data are compared to current ab initio predictions.

  4. Tracking millennial-scale Holocene glacial advance and retreat using Osmium isotopes: Insights from the Greenland Ice Sheet

    NASA Astrophysics Data System (ADS)

    Rooney, Alan; Selby, David; Lloyd, Jeremy; Roberts, David; Lückge, Andreas; Sageman, Bradley; Prouty, Nancy

    2016-04-01

    Using new high-resolution osmium (Os) isotope stratigraphy from cores adjacent to the Greenland ice sheet we highlight the potential for chemostratigraphy to contribute to our understanding of ice sheet dynamics. This study utilizes sediment cores that have excellent chronological controls and demonstrates the role of local and regional weathering fluxes on the marine Os residence time. Distal to the Greenland ice streams core MSM-520 displays a steady lowering of the Os isotope composition during the Holocene. In contrast, proximal to the calving front of Jakobshavn Isbræ (core DA00-06), the Os isotope stratigraphy highlights four stages of ice stream retreat and advance. Our chemostratigraphic records provide vital benchmarks as we attempt to better constrain the future response of major ice sheets to climate change. Variations in Os isotope composition from sediment and macro-algae (seaweed) sourced from both near-field and far-field settings emphasize the overwhelming effect local weathering sources have on seawater Os isotope composition.

  5. Geodetic Constraints on Mantle Q at Periods from a Fortnight to 18.6 Years

    NASA Astrophysics Data System (ADS)

    Benjamin, D.; Wahr, J.; Desai, S.

    2002-12-01

    Seismic observations have provided numerous constraints on the earth's spherically-averaged mantle anelasticity at periods of tens of minutes and shorter. Meanwhile, post-glacial rebound and other geodynamic studies provide information at periods of a few thousand years and longer. However, constraints at intermediate periods are scarce. Such constraints could be useful in trying to connect the seismic anelastic models with the longer-period visco-elastic behavior. Here we will describe constraints on anelasticity in this intermediate range of periods as obtained from earth tide and earth rotation observations. We discuss results from: (1) VLBI observations of the monthly and fortnightly tidal variations in rotation rate; (2) satellite laser ranging observations of the 18.6-year tidal variations in the earth's gravitational field; and (3) astrometric and geodetic observations of the 14-month Chandler Wobble period and damping. We find that these observations are consistent with a nearly frequency-independent mantle Q stretching from seismic periods all the way out to the 14-month Chandler Wobble period; but that Q appears to decrease significantly between 14-months and 18.6-years.

  6. Significant contribution of the 18.6 year tidal cycle to regional coastal changes

    NASA Astrophysics Data System (ADS)

    Gratiot, N.; Anthony, E. J.; Gardel, A.; Gaucherel, C.; Proisy, C.; Wells, J. T.

    2008-03-01

    Although rising global sea levels will affect the shape of coastlines over the coming decades, the most severe and catastrophic shoreline changes occur as a consequence of local and regional-scale processes. Changes in sediment supply and deltaic subsidence, both natural or anthropogenic, and the occurrences of tropical cyclones and tsunamis have been shown to be the leading controls on coastal erosion. Here, we use satellite images of South American mangrove-colonized mud banks collected over the past twenty years to reconstruct changes in the extent of the shoreline between the Amazon and Orinoco rivers. The observed timing of the redistribution of sediment and migration of the mud banks along the 1,500km muddy coast suggests the dominant control of ocean forcing by the 18.6 year nodal tidal cycle. Other factors affecting sea level such as global warming or El Niño and La Niña events show only secondary influences on the recorded changes. In the coming decade, the 18.6 year cycle will result in an increase of mean high water levels of 6cm along the coast of French Guiana, which will lead to a 90m shoreline retreat.

  7. Configuration assignments to isomers in the neutron-rich 186Ta (Z =73 ) nucleus

    NASA Astrophysics Data System (ADS)

    Sood, P. C.; Gowrishankar, R.

    2014-12-01

    Though the neutron-rich odd-odd nucleus Ta18673113 was first produced in 1955, even after 60 years its ground state (g.s.) and both of its two other isomers remain undefined. We use the well-tested two-quasiparticle rotor model, which explicitly includes residual neutron-proton n -p interaction and other contributing factors, to evaluate the bandhead energies of the physically admissible low-lying two-particle structures in 186Ta with inputs from experimentally observed structures in neighboring isotopes and isotones to characterize these levels. Our analysis assigns Kπ = 5-{p :7 /2 [404 ]⊗n :3 /2 [512 ]} configuration to the 10.5 min 186Ta (g.s.) and the antiparallel-spin Kπ=2- of the same configuration to the 1.54 min isomer with Ex = 90(10) keV. We further assign Kπ=8-{p :7 /2 [404 ]⊗n :9 /2 [505 ]} configuration to the recently identified 3.0 min isomer with Ex=336 (20) keV. These assignments are shown to be consistent with all the available experimental data. Further, they are seen to fit nicely as another instance of highly hindered Δ I =3 isomeric transitions, and also of low-lying long-lived isomer triplets, frequently observed in numerous odd-odd Z =61 (2 )75 nuclides.

  8. Improving accuracy and reliability of 186-keV measurements for unattended enrichment monitoring

    SciTech Connect

    Ianakiev, Kiril D; Boyer, Brian D; Swinhoe, Martyn T; Moss, Calvin E; Goda, Joetta M; Favalli, Andrea; Lombardi, Marcie; Paffett, Mark T; Hill, Thomas R; MacArthur, Duncan W; Smith, Morag K

    2010-04-13

    Improving the quality of safeguards measurements at Gas Centrifuge Enrichment Plants (GCEPs), whilst reducing the inspection effort, is an important objective given the number of existing and new plants that need to be safeguarded. A useful tool in many safeguards approaches is the on-line monitoring of enrichment in process pipes. One aspect of this measurement is a simple, reliable and precise passive measurement of the 186-keV line from {sup 235}U. (The other information required is the amount of gas in the pipe. This can be obtained by transmission measurements or pressure measurements). In this paper we describe our research efforts towards such a passive measurement system. The system includes redundant measurements of the 186-keV line from the gas and separately from the wall deposits. The design also includes measures to reduce the effect of the potentially important background. Such an approach would practically eliminate false alarms and can maintain the operation of the system even with a hardware malfunction in one of the channels. The work involves Monte Carlo modeling and the construction of a proof-of-principle prototype. We will carry out experimental tests with UF{sub 6} gas in pipes with and without deposits in order to demonstrate the deposit correction.

  9. Photodisintegration of the isotopes {sup 186,188,189,190,192}Os: Similarities and distinctions

    SciTech Connect

    Varlamov, V. V.; Makarov, M. A.; Peskov, N. N.; Stepanov, M. E.

    2015-09-15

    In addition to the results obtained earlier for the isotopes {sup 188,189}Os, experimental data on the photodisintegration of the isotopes {sup 186,190,192}Os are analyzed on the basis of specially introduced objective criteria of reliability of data on the cross sections for partial photoneutron reactions. It is found that the (γ, 1n), (γ, 2n), and (γ, 3n) cross sections for each isotope satisfy differently or, on the contrary, do not satisfy the data-reliability criteria. In many cases, the multiplicity transition functions specified as the ratios F{sub i} = σ(γ, in)/σ(γ, xn) of the cross sections for the (γ, in) partial reactions to the neutron-yield reaction cross section σ(γ, xn) = σ(γ, 1n) + 2σ(γ, 2n) + 3σ(γ, 3n) +... have values that are physically unreliable by definition. It is shown that ambiguities in the dependence of significant systematic uncertainties in experimentally determined neutron multiplicities on the measured kinetic energies is the reason for this. The dependence of these uncertainties on the energy spectra of neutrons is analyzed. For the isotopes {sup 186,190,192}Os, new evaluated data satisfying the data-reliability criteria are obtained for the cross sections for partial and total photoneutron reactions.

  10. Home Sweet Home?: Determining Habitability From the Eccentricities of Kepler-186

    NASA Astrophysics Data System (ADS)

    McTier, Moiya; Kipping, David M.

    2016-01-01

    In the search for habitable exoplanets, astronomers' primary criterion has historically been that the planet's equilibrium temperature be suitable for liquid water. Equilibrium temperature is often determined assuming a circular orbit and, therefore, a constant star-planet separation, especially for low-mass transiting exoplanets. Using photometric data from the first Kepler mission, we analyze the transit light curves of Kepler 186, an exoplanetary system located approximately 150pc from Earth. In this poster, we report new lower limits on the eccentricities of the system found using the astrodensity profiling method and discuss how those values effect habitabilty. We also report other orbital, stellar, and planetary properties, which are consistent with, though slightly more precise than, the values reported in Quintana et al, 2014. We assert that, with an eccentricity of 0.092, a semimajor axis of 0.35 AU, and a radius of 1.06 Earth radii, Kepler 186f is an Earth-sized exoplanet that spends its entire orbit in the habitable zone of its star.

  11. Fast-neutron interactions with /sup 182/W, /sup 184/W and /sup 186/W

    SciTech Connect

    Guenther, P.T.; Smith, A.B.; Whalen, J.F.

    1981-06-01

    Neutron total cross sections of /sup 182/W, /sup 184/W and /sup 186/W are measured from approx. = 0.3 to 5.0 MeV at intervals of less than or equal to 50 keV to accuracies of 1 to 3%. Differential neutron elastic- and inelastic-scattering cross sections of the same three isotopes are measured at scattering angles in the range 20 to 160/sup 0/ and at incident-neutron energy intervals of approx. = 100 keV from 1.5 to 4.0 MeV. Approximately thirty scattered-neutron groups are observed for each of the isotopes. Prominent of these are excitations attributed to collective rotational and vibrational bands. The experimental results are interpreted in terms of optical-statistical and coupled-channels models with particular attention to the direct excitation of ground-state-rotational and ..beta..- and ..gamma..-vibrational bands. The strengths of the direct interactions and the magnitudes of the collective deformations are inferred from the interpretations and compared with similar values previously reported elsewhere. The experimental results are used to deduce experimentally-based evaluated data sets for /sup 182/W, /sup 184/W and /sup 186/W over the energy range 0.1 - approx. = 5.0 MeV.

  12. Histamine H3 receptor antagonist OUP-186 attenuates the proliferation of cultured human breast cancer cell lines.

    PubMed

    Tanaka, Satoshi; Sakaguchi, Minoru; Yoneyama, Hiroki; Usami, Yoshihide; Harusawa, Shinya

    2016-11-18

    Histamine is involved in various physiological functions, including its neurotransmitter actions in the central nervous system and its action as a causative agent of inflammation, allergic reactions, and gastric acid secretions. Histamine expression and biosynthesis have been detected in breast cancer cells. It was recently suggested that the histamine H3 receptor (H3R) plays a role in the proliferation of breast cancer cells. We recently developed the non-imidazole H3R antagonist OUP-186 which exhibited a potent and selective human H3R antagonistic activity as well as no activity against the human histamine H4 receptor (H4R). In this study, we compared the effects of OUP-186 on the proliferation of estrogen receptor negative (ER-) breast cancer cells (MDA-MB-231) and ER+ breast cancer cells (MCF7) to the effects of clobenpropit (potent imidazole-containing H3R antagonist). OUP-186 and clobenpropit suppressed the proliferation of breast cancer cells. The IC50 values at 48 h for OUP-186 and clobenpropit were approximately 10 μM and 50 μM, respectively. Furthermore, OUP-186 potently induced cell death by activating caspase-3/7, whereas cell death was only slightly induced by clobenpropit. In addition, OUP-186 treatment blocked the proliferation increase triggered by 100 μM (R)-(-)-α-methylhistamine (H3R agonist). The use of 4-methylhistamine (H4R agonist) and JNJ10191584 (selective H4R antagonist) did not affect breast cancer proliferation. These results indicate that OUP-186 potently suppresses proliferation and induces caspase-dependent apoptotic death in both ER+ and ER-breast cancer cells.

  13. Potent organometallic osmium compounds induce mitochondria-mediated apoptosis and S-phase cell cycle arrest in A549 non-small cell lung cancer cells.

    PubMed

    van Rijt, Sabine H; Romero-Canelón, Isolda; Fu, Ying; Shnyder, Steve D; Sadler, Peter J

    2014-05-01

    The problems of acquired resistance associated with platinum drugs may be addressed by chemotherapeutics based on other transition metals as they offer the possibility of novel mechanisms of action. In this study, the cellular uptake and induction of apoptosis in A549 human non-small cell lung cancer cells of three promising osmium(II) arene complexes containing azopyridine ligands, [Os(η(6)-arene)(p-R-phenylazopyridine)X]PF6, where arene is p-cymene or biphenyl, R is OH or NMe2, and X is Cl or I, were investigated. These complexes showed time-dependent (4–48 h) potent anticancer activity with highest potency after 24 h (IC50 values ranging from 0.1 to 3.6 μM). Cellular uptake of the three compounds as quantified by ICP-MS, was independent of their logP values (hydrophobicity). Furthermore, maximum cell uptake was observed after 24 h, with evident cell efflux of the osmium after 48 and 72 h of exposure, which correlated with the corresponding IC50 values. The most active compound 2, [Os(η(6)-p-cymene)(NMe2-phenylazopyridine)I]PF6, was taken up by lung cancer cells predominately in a temperature-dependent manner indicating that energy-dependent mechanisms are important in the uptake of 2. Cell fractionation studies showed that all three compounds accumulated mainly in cellular membranes. Furthermore, compound 2 induced apoptosis and caused accumulation in the S-phase of the cell cycle. In addition, 2 induced cytochrome c release and alterations in mitochondrial membrane potential even after short exposure times, indicating that mitochondrial apoptotic pathways are involved. This study represents the first steps towards understanding the mode of action of this promising class of new osmium-based chemotherapeutics.

  14. Enhancement of Near-IR Photoelectric Conversion in Dye-Sensitized Solar Cells Using an Osmium Sensitizer with Strong Spin-Forbidden Transition.

    PubMed

    Kinoshita, Takumi; Fujisawa, Jun-Ichi; Nakazaki, Jotaro; Uchida, Satoshi; Kubo, Takaya; Segawa, Hiroshi

    2012-02-02

    A new osmium (Os) complex of the [Os(tcterpy)-(4,4'-bis(p-butoxystyryl)-2,2'-bipyridine)Cl]PF6 (Os-stbpy) has been synthesized and characterized for dye-sensitized solar cells (DSSCs). The Os-stbpy dye shows enhanced spin-forbidden absorptions around 900 nm. The DSSCs with Os-stbpy show a wide-band spectral response up to 1100 nm with high overall conversion efficiency of 6.1% under standard solar illumination.

  15. Evidence for [gamma] vibrations and shape evolutions through the transitional [sup 184,186,188,190]Hg nuclei

    SciTech Connect

    Delaroche, J.P.; Girod, M. ); Bastin, G.; Deloncle, I.; Hannachi, F.; Libert, J.; Porquet, M.G. ); Bourgeois, C.; Hojman, D.; Kilcher, P.; Korichi, A.; Le Blanc, F.; Perrin, N.; Roussiere, B.; Sauvage, J.; Sergolle, H. )

    1994-11-01

    Constrained Hartree-Fock-Bogoliubov calculations based on Gogny's force have been performed to determine the potential energy surfaces, collective masses, and moments of inertia used to build a five-dimension collective Hamiltonian treating quadrupole motion in the [sup 184,186,188,190]Hg isotopes. Many collective states have been predicted at low excitation energy, some of them forming [gamma]-vibrational bands. To expand experimental information on [gamma] bands, high statistics measurements on the [beta][sup +] and electron capture decay of [sup 190]Tl[sup [ital g],][ital m] and [sup 186]Tl[sup [ital g],][ital m] have been performed at the ISOCELE facility. For the first time, [gamma] bands have been identified in [sup 190]Hg and [sup 186]Hg. These new results together with previous experimental information available on the ground state and [ital K]=0 excited bands in [sup 184,186,188,190]Hg form a database which has been analyzed and discussed in the present theoretical framework. It is argued that the first [ital K]=0 excited band in [sup 190]Hg is a [beta]-vibrational band, and that [sup 186]Hg is a nucleus in which shape coexistence occurs not only for the [ital K]=0 bands but also for the [gamma] bands.

  16. Unveiling the sodium intercalation properties in Na1.86□0.14Fe3(PO4)3

    NASA Astrophysics Data System (ADS)

    Essehli, R.; Ben Yahia, H.; Maher, K.; Sougrati, M. T.; Abouimrane, A.; Park, J.-B.; Sun, Y.-K.; Al-Maadeed, M. A.; Belharouak, I.

    2016-08-01

    The new compound Na1.86□0.14Fe3(PO4)3 was successfully synthesized via hydrothermal synthesis and its crystal structure was determined using powder X-ray diffraction data. Na1.86Fe3(PO4)3 was also characterized by operando XRD and Mössbauer spectroscopy, cyclic voltammetry, and galvanostatic cycling. Na1.86Fe3(PO4)3 crystallizes with the alluaudite-type structure with the eight coordinated Na1 and Na2 sodium atoms located within the channels. The combination of the Rietveld- and Mössbauer-analyses confirms that the sodium vacancies in the Na1 site are linked to a partial oxidation of Fe2+ during synthesis. The electrochemical tests indicated that Na1.86Fe3(PO4)3 is a 3 V sodium intercalating cathode. At the current densities of 5, 10, and 20 mA g-1, the material delivers the specific capacities of 109, 97, and 80 mA h g-1, respectively. After 100 charge and discharge cycles, Na1.86Fe3(PO4)3 exhibited good sodium removal and uptake behavior although no optimizations of particle size, morphology, and carbon coating were performed.

  17. Osmium isotope perturbations during the Pliensbachian-Toarcian (Early Jurassic): Relationships between volcanism, weathering, and climate change

    NASA Astrophysics Data System (ADS)

    Percival, Lawrence; Cohen, Anthony; Davies, Marc; Dickson, Alexander; Jenkyns, Hugh; Hesselbo, Stephen; Mather, Tamsin; Xu, Weimu; Storm, Marisa

    2016-04-01

    The Mesozoic Era marked a time of greenhouse conditions on Earth, punctuated by a number of abrupt perturbations to the carbon cycle, such as Ocean Anoxic Events (OAEs). OAEs are typically marked in the stratigraphic record by the appearance of organic-rich shales, and excursions in carbon-isotope ratios registered in carbonates and organic matter. A range of geochemical evidence indicates changes to global temperatures, typically featuring abrupt warming possibly caused by CO2 emissions resulting from Large Igneous Province (LIP) volcanism. A warmer atmosphere is thought to have led to changes in the global hydrological cycle, which would likely have enhanced global weathering rates. The Toarcian OAE (T-OAE) is inferred, from osmium isotope ratios in organic-rich mudrocks from Yorkshire and western North America, to have been a time of such increased weathering rates. However, it is likely that the sediments at these locations were deposited in relatively hydrographically restricted environments, potentially more susceptible to the influence of local input; consequently, they may not offer the best representation of the global seawater Os-isotope composition at that time. In this study, we have measured the osmium isotope composition of siciliclastic mudrocks in a core from the Mochras borehole (Llanbedr Farm, Cardigan Bay Basin, Wales), which constitutes a sedimentary record for a fully open-marine seaway that connected Tethys to the Boreal ocean during the Toarcian. We analysed samples from strata including both the T-OAE and preceding Pliensbachian-Toarcian boundary (Pl-To), both of which record multiple geochemical excursions and records of elevated extinction amongst benthic fauna. We find that the latest Pliensbachian records seawater 187Os/188Os of ~0.35-0.4, rising to ~0.5 at the Pl-To boundary, before a further rise to ~0.7 during the T-OAE. We conclude that such increases in radiogenic Os flux to the ocean system resulted from enhanced continental

  18. Collectivity and Configuration Mixing in {sup 186,188}Pb and {sup 194}Po

    SciTech Connect

    Grahn, T.; Julin, R.; Eeckhaudt, S.; Greenlees, P. T.; Jones, P.; Juutinen, S.; Kettunen, H.; Leino, M.; Leppaenen, A.-P.; Nieminen, P.; Nyman, M.; Rahkila, P.; Sandzelius, M.; Saren, J.; Scholey, C.; Uusitalo, J.; Dewald, A.; Moeller, O.; Christen, S.; Jolie, J.

    2006-08-11

    Lifetimes of prolate intruder states in {sup 186}Pb and oblate intruder states in {sup 194}Po have been determined by employing, for the first time, the recoil-decay tagging technique in recoil distance Doppler-shift lifetime measurements. In addition, lifetime measurements of prolate states in {sup 188}Pb up to the 8{sup +} state were carried out using the recoil-gating method. The B(E2) values have been deduced from which deformation parameters vertical bar {beta}{sub 2} vertical bar =0.29(5) and vertical bar {beta}{sub 2} vertical bar =0.17(3) for the prolate and the oblate bands, respectively, have been extracted. The results also shed new light on the mixing between different shapes.

  19. Updated Peach Bottom Model for MELCOR 1.8.6: Description and Comparisons

    SciTech Connect

    Robb, Kevin R

    2014-09-01

    A MELCOR 1.8.5 model of the Peach Bottom Unit 2 or 3 has been updated for MELCOR 1.8.6. Primarily, this update involved modification of the lower head modeling. Three additional updates were also performed. First, a finer nodalization of the containment wet well was employed. Second, the pressure differential used by the logic controlling the safety relief valve actuation was modified. Finally, an additional stochastic failure mechanism for the safety relief valves was added. Simulation results from models with and without the modifications were compared. All the analysis was performed by comparing key figures of merit from simulations of a long-term station blackout scenario. This report describes the model changes and the results of the comparisons.

  20. Thermal neutron radiative capture cross-section of 186W(n, γ)187W reaction

    NASA Astrophysics Data System (ADS)

    Tan, V. H.; Son, P. N.

    2016-06-01

    The thermal neutron radiative capture cross section for 186W(n, γ)187W reaction was measured by the activation method using the filtered neutron beam at the Dalat research reactor. An optimal composition of Si and Bi, in single crystal form, has been used as neutron filters to create the high-purity filtered neutron beam with Cadmium ratio of Rcd = 420 and peak energy En = 0.025 eV. The induced activities in the irradiated samples were measured by a high resolution HPGe digital gamma-ray spectrometer. The present result of cross section has been determined relatively to the reference value of the standard reaction 197Au(n, γ)198Au. The necessary correction factors for gamma-ray true coincidence summing, and thermal neutron self-shielding effects were taken into account in this experiment by Monte Carlo simulations.

  1. Luni-solar 18.6-year signal in tree-rings from Argentina and Chile

    NASA Astrophysics Data System (ADS)

    Cùrrie, Robert G.

    1991-09-01

    Spectrum analysis of 32 tree-ring chronologies from Argentina and Chile yields evidence for two peaks with periods 19.2±1.6 years (30 out of 32 records) and 10.5±0.4 years in 22 instances. Tests by the t-statistic show that the long-period peak is significant at a confidence level of 99%. This signal is identified as the luni-solar 18.6-year M n term reported earlier by Currie (1983) in two treering chronologies from the same region, and later in tree-rings from North America, Tasmania, New Zealand, and South Africa ( Currie, 1991a-c). Amplitude and phase of the M n signal are nonstationary with respect to both time and geography. In particular, abrupt 180° phase changes in wave polarity are often observed.

  2. 186 K Operation of Terahertz Quantum-Cascade Lasers Based on a Diagonal Design

    NASA Technical Reports Server (NTRS)

    Kumar, Sushil; Hu, Qing; Reno, John L.

    2009-01-01

    Resonant-phonon terahertz quantum-cascade lasers operating up to a heat-sink temperature of 186 K are demonstrated. This record temperature performance is achieved based on a diagonal design, with the objective to increase the upper-state lifetime and therefore the gain at elevated temperatures. The increased diagonality also lowers the operating current densities by limiting the flow of parasitic leakage current. Quantitatively, the diagonality is characterized by a radiative oscillator strength that is smaller by a factor of two from the least of any previously published designs. At the lasing frequency of 3.9 THz, 63 mW of peak optical power was measured at 5 K, and approximately 5 mW could still be detected at 180 K.

  3. Complex Förster energy transfer interactions between semiconductor quantum dots and a redox-active osmium assembly.

    PubMed

    Stewart, Michael H; Huston, Alan L; Scott, Amy M; Efros, Alexander L; Melinger, Joseph S; Gemmill, Kelly Boeneman; Trammell, Scott A; Blanco-Canosa, Juan B; Dawson, Philip E; Medintz, Igor L

    2012-06-26

    The ability of luminescent semiconductor quantum dots (QDs) to engage in diverse energy transfer processes with organic dyes, light-harvesting proteins, metal complexes, and redox-active labels continues to stimulate interest in developing them for biosensing and light-harvesting applications. Within biosensing configurations, changes in the rate of energy transfer between the QD and the proximal donor, or acceptor, based upon some external (biological) event form the principle basis for signal transduction. However, designing QD sensors to function optimally is predicated on a full understanding of all relevant energy transfer mechanisms. In this report, we examine energy transfer between a range of CdSe-ZnS core-shell QDs and a redox-active osmium(II) polypyridyl complex. To facilitate this, the Os complex was synthesized as a reactive isothiocyanate and used to label a hexahistidine-terminated peptide. The Os-labeled peptide was ratiometrically self-assembled to the QDs via metal affinity coordination, bringing the Os complex into close proximity of the nanocrystal surface. QDs displaying different emission maxima were assembled with increasing ratios of Os-peptide complex and subjected to detailed steady-state, ultrafast transient absorption, and luminescence lifetime decay analyses. Although the possibility exists for charge transfer quenching interactions, we find that the QD donors engage in relatively efficient Förster resonance energy transfer with the Os complex acceptor despite relatively low overall spectral overlap. These results are in contrast to other similar QD donor-redox-active acceptor systems with similar separation distances, but displaying far higher spectral overlap, where charge transfer processes were reported to be the dominant QD quenching mechanism.

  4. Coronary artery wall imaging in mice using osmium tetroxide and micro-computed tomography (micro-CT)

    SciTech Connect

    Pai, Vinay M.; Kozlowski, Megan; Donahue, Danielle; Miller, Elishiah; Xiao, Xianghui; Chen, Marcus Y.; Yu, Zu-Xi; Connelly, Patricia; Jeffries, Kenneth; Wen, Han

    2012-05-10

    The high spatial resolution of micro-computed tomography (micro-CT) is ideal for 3D imaging of coronary arteries in intact mouse heart specimens. Previously, micro-CT of mouse heart specimens utilized intravascular contrast agents that hardened within the vessel lumen and allowed a vascular cast to be made. However, for mouse coronary artery disease models, it is highly desirable to image coronary artery walls and highlight plaques. For this purpose, we describe an ex vivo contrast-enhanced micro-CT imaging technique based on tissue staining with osmium tetroxide (OsO{sub 4}) solution. As a tissue-staining contrast agent, OsO{sub 4} is retained in the vessel wall and surrounding tissue during the fixation process and cleared from the vessel lumens. Its high X-ray attenuation makes the artery wall visible in CT. Additionally, since OsO{sub 4} preferentially binds to lipids, it highlights lipid deposition in the artery wall. We performed micro-CT of heart specimens of 5- to 25-week-old C57BL/6 wild-type mice and 5- to 13-week-old apolipoprotein E knockout (apoE{sup -/-}) mice at 10 {mu}m resolution. The results show that walls of coronary arteries as small as 45 {mu}m in diameter are visible using a table-top micro-CT scanner. Similar image clarity was achieved with 1/2000th the scan time using a synchrotron CT scanner. In 13-week-old apoE mice, lipid-rich plaques are visible in the aorta. Our study shows that the combination of OsO{sub 4} and micro-CT permits the visualization of the coronary artery wall in intact mouse hearts.

  5. Electron transfer across multiple hydrogen bonds: the case of ureapyrimidinedione-substituted vinyl ruthenium and osmium complexes.

    PubMed

    Pichlmaier, Markus; Winter, Rainer F; Zabel, Manfred; Zális, Stanislav

    2009-04-08

    Ruthenium and osmium complexes 2a,b and 3a,b featuring the N-4,6-dioxo-5,5-dibutyl- or the N-4,6-dioxo-5,5-di-(2-propenyl)-1,4,5,6-tetrahydropyrimidin-2-yl-N'(4-ethenylphenyl)-urea ligand dimerize by a self-complementary quadruply hydrogen-bonding donor/donor/acceptor/acceptor (DDAA) motif. We provide evidence that the dimeric structures are maintained in nonpolar solvents and in 0.1 M NBu(4)PF(6)/CH(2)Cl(2) supporting electrolyte solution. All complexes are reversibly oxidized in two consecutive two-electron oxidations (DeltaE(1/2) approximately = 500 mV) without any discernible potential splitting for the oxidation of the individual hydrogen-bridged redox active moieties. IR and UV/vis/NIR spectroelectrochemistry show a one-step conversion of the neutral to the dication without any discernible features of an intermediate monooxidized radical cation. Oxidation-induced IR changes of the NH and CO groups that are involved in hydrogen bonding are restricted to the styryl-bonded urea NH function. IR band assignments are aided by quantum chemical calculations. Our experimental findings clearly show that, at least in the present systems, the ureapyrimidinedione (Upy) DDAA hydrogen-bonding motif does not support electron transfer. The apparent reason is that neither of the hydrogen-bonding functionalities contributes to the occupied frontier levels. This results in nearly degenerate pairs of MOs representing the in-phase and out-of-phase combinations of the individual monomeric building blocks.

  6. Pharmacokinetics and normal organ dosimetry following intraperitoneal rhenium-186-labeled monoclonal antibody

    SciTech Connect

    Breitz, H.B.; Durham, J.S.; Fisher, D.R. |||

    1995-05-01

    Pharmacokinetics, biodistribution and radiation dose estimates following intraperitoneal administration of a {sup 186}Re-labeled murine antibody, NR-LU-10, were assessed in 27 patients with advanced ovarian cancer. Quantitative gamma camera imaging and gamma counting of serum and intraperitoneal fluid radioactivity were used to obtain data for dosimetry estimation. The MIRD intraperitoneal model was used to estimate dose to normal organs from radioactivity within the peritoneal cavity. The absorbed dose to normal peritoneum was estimated in two ways: from the gamma camera activity and peritoneal fluid samples. Serum activity peaked at 44 hr and depended on the concentration of radioactivity in the peritoneal fluid. Mean cumulative urinary excretion of {sup 186}Re was 50% by 140 hr. Estimates of radiation absorbed dose to normal organs in rad/mCi administered (mean {plus_minus} s.d.) were whole body 0.7 {plus_minus} 0.3; marrow 0.4 {plus_minus}0.1; liver 1.9 {plus_minus}0.9; lungs 1.3 {plus_minus} 0.7; kidneys 0.2 {plus_minus} 0.2; intestine 0.2 {plus_minus}0.2. Peritoneal surface dose estimates varied depending on the volume of fluid infused and the method of dose determination. Using gamma camera data, the peritoneal dose ranged for 7 to 36 rad/mCi. Using peritoneal fluid sample data, the dose ranged from 2 to 25 rad/mCi. Significant myelosuppression was observed at marrow doses above 100 rad. Noninvasive methods of dose estimation for intraperitoneal administration of radioimmunoconjugates provide reasonable estimates when compared with previously described methods. 31 refs., 6 figs., 2 tabs.

  7. En route to osmium analogues of KP1019: synthesis, structure, spectroscopic properties and antiproliferative activity of trans-[Os(IV)Cl4(Hazole)2].

    PubMed

    Büchel, Gabriel E; Stepanenko, Iryna N; Hejl, Michaela; Jakupec, Michael A; Keppler, Bernhard K; Arion, Vladimir B

    2011-08-15

    By controlled Anderson type rearrangement reactions complexes of the general formula trans-[Os(IV)Cl(4)(Hazole)(2)], where Hazole = 1H-pyrazole, 2H-indazole, 1H-imidazole, and 1H-benzimidazole, have been synthesized. Note that 2H-indazole tautomer stabilization in trans-[Os(IV)Cl(4)(2H-indazole)(2)] is unprecedented in coordination chemistry of indazole. The metal ion in these compounds possesses the same coordination environment as ruthenium(III) in (H(2)ind)[Ru(III)Cl(4)(Hind)(2)], where Hind = 1H-indazole, (KP1019), an investigational anticancer drug in phase I clinical trials. These osmium(IV) complexes are appropriate precursors for the synthesis of osmium(III) analogues of KP1019. In addition the formation of an adduct of trans-[Os(IV)Cl(4)(Hpz)(2)] with cucurbit[7]uril is described. The compounds have been comprehensively characterized by elemental analysis, EI and ESI mass spectrometry, spectroscopy (IR, UV-vis, 1D and 2D NMR), cyclic voltammetry, and X-ray crystallography. Their antiproliferative acitivity in the human cancer cell lines CH1 (ovarian carcinoma), A549 (nonsmall cell lung carcinoma), and SW480 (colon carcinoma) is reported.

  8. Antiferromagnetic transitions of osmium-containing rare earth double perovskites Ba{sub 2}LnOsO{sub 6} (Ln=rare earths)

    SciTech Connect

    Hinatsu, Yukio Doi, Yoshihiro; Wakeshima, Makoto

    2013-10-15

    The perovskite-type compounds containing both rare earth and osmium Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm–Lu) have been prepared. Powder X-ray diffraction measurements and Rietveld analysis show that Ln{sup 3+} and Os{sup 5+} ions are structurally ordered at the M site of the perovskite BaMO{sub 3}. Magnetic susceptibility and specific heat measurements show that an antiferromagnetic ordering of Os{sup 5+} ions has been observed for Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm, Eu, Gd, Lu) at 65–71 K. Magnetic ordering of Ln{sup 3+} moments occurs when the temperature is furthermore decreased. - Graphical abstract: The perovskite-type compounds containing both rare earth and osmium Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm–Lu) have been prepared. An antiferromagnetic ordering of Os{sup 5+} ions has been observed for Ba{sub 2}LnOsO{sub 6} (Ln=Pr, Nd, Sm, Eu, Gd, Lu) at 65–71 K. Measurements and analysis of the specific heat for Ba{sub 2}PrOsO{sub 6} show that magnetic ordering of the Pr{sup 3+} moments should have occurred at ∼20 K. Display Omitted.

  9. Luminescence response of an osmium(II) complex to macromolecular polyanions for the detection of heparin and chondroitin sulfate in biomedical preparations.

    PubMed

    Wu, Hao; Wu, Jain; Saez, Christopher; Campana, Maria; Megehee, Elise G; Wang, Enju

    2013-12-04

    Heparin, dextran sulfate (DS), chondroitin sulfate (CS), and carrageenan are found to enhance the luminescence intensity of an osmium(II) carbonyl complex with phenanthroline (phen) and 4-phenylpyridine (4-phpy) ligands in aqueous and ethanol solutions. The enhancing effect of the polyanions on the luminescence of the complex is heavily dependent on the sulfate content and other factors such as structure, solubility, and counter ions of the polyanion. The highly sulfated dextran and ι-carrageenan have the most profound effect, while the low charged κ-carrageenan and CS have the least response in aqueous solution. All polyanions exhibited enhanced luminescence intensity of the complex in ethanol solutions, and even the low charged CS and κ-carrageenan enhanced the luminescence more than 4 times. DS contamination of the sodium heparin at 5% can show a significant increase in luminescence response. The osmium complex is found to be highly successful in the fast and sensitive detection of heparin in commercial injectable samples with various backgrounds as well as the detection of CS in over the counter food supplement tablets.

  10. 21 CFR 186.1 - Substances added indirectly to human food affirmed as generally recognized as safe (GRAS).

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 3 2014-04-01 2014-04-01 false Substances added indirectly to human food affirmed... GENERALLY RECOGNIZED AS SAFE General Provisions § 186.1 Substances added indirectly to human food affirmed... use of such substance for the purpose of adding the ingredient to the food through extraction from...

  11. 36 CFR 18.6 - Are there limitations on the use of property leased under this part?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Director determines in accordance with 36 CFR part 51 and park area planning documents and related... PARK SERVICE, DEPARTMENT OF THE INTERIOR LEASING OF PROPERTIES IN PARK AREAS § 18.6 Are there... the Director determines in accordance with park area planning documents and related guidelines...

  12. Chemical Abundances of M-dwarfs from the APOGEE Survey. I. The Exoplanet Hosting Stars Kepler-138 and Kepler-186

    NASA Astrophysics Data System (ADS)

    Souto, D.; Cunha, K.; García-Hernández, D. A.; Zamora, O.; Allende Prieto, C.; Smith, V. V.; Mahadevan, S.; Blake, C.; Johnson, J. A.; Jönsson, H.; Pinsonneault, M.; Holtzman, J.; Majewski, S. R.; Shetrone, M.; Teske, J.; Nidever, D.; Schiavon, R.; Sobeck, J.; García Pérez, A. E.; Gómez Maqueo Chew, Y.; Stassun, K.

    2017-02-01

    We report the first detailed chemical abundance analysis of the exoplanet-hosting M-dwarf stars Kepler-138 and Kepler-186 from the analysis of high-resolution (R ∼ 22,500) H-band spectra from the SDSS-IV–APOGEE survey. Chemical abundances of 13 elements—C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe—are extracted from the APOGEE spectra of these early M-dwarfs via spectrum syntheses computed with an improved line list that takes into account H2O and FeH lines. This paper demonstrates that APOGEE spectra can be analyzed to determine detailed chemical compositions of M-dwarfs. Both exoplanet-hosting M-dwarfs display modest sub-solar metallicities: [Fe/H]Kepler-138 = ‑0.09 ± 0.09 dex and [Fe/H]Kepler-186 = ‑0.08 ± 0.10 dex. The measured metallicities resulting from this high-resolution analysis are found to be higher by ∼0.1–0.2 dex than previous estimates from lower-resolution spectra. The C/O ratios obtained for the two planet-hosting stars are near-solar, with values of 0.55 ± 0.10 for Kepler-138 and 0.52 ± 0.12 for Kepler-186. Kepler-186 exhibits a marginally enhanced [Si/Fe] ratio.

  13. mer, fac, and Bidentate Coordination of an Alkyl-POP Ligand in the Chemistry of Nonclassical Osmium Hydrides.

    PubMed

    Esteruelas, Miguel A; García-Yebra, Cristina; Martín, Jaime; Oñate, Enrique

    2017-01-03

    Nonclassical and classical osmium polyhydrides containing the diphosphine 9,9-dimethyl-4,5-bis(diisopropylphosphino)xanthene (xant(P(i)Pr2)2), coordinated in κ(3)-mer, κ(3)-fac, and κ(2)-P,P fashions, have been isolated during the cyclic formation of H2 by means of the sequential addition of H(+) and H(-) or H(-) and H(+) to the classical trihydride OsH3Cl{xant(P(i)Pr2)2} (1). This complex adds H(+) to form the compressed dihydride dihydrogen complex [OsCl(H···H)(η(2)-H2){xant(P(i)Pr2)2}](+) (2). Under argon, cation 2 loses H2 and the resulting unsaturated fragment dimerizes to give [(Os(H···H){xant(P(i)Pr2)2})2(μ-Cl)2](2+) (3). During the transformation the phosphine changes its coordination mode from mer to fac. The benzofuran counterpart of 1, OsH3Cl{dbf(P(i)Pr2)2} (4; dbf(P(i)Pr2)2 = 4,6-bis(diisopropylphosphino)dibenzofuran), also adds H(+) to afford the benzofuran counterpart of 2, [OsCl(H···H)(η(2)-H2){xant(P(i)Pr2)2}](+) (5), which in contrast to the latter is stable and does not dimerize. Acetonitrile breaks the chloride bridge of 3 to form the dihydrogen [OsCl(η(2)-H2)(CH3CN){xant(P(i)Pr2)2}](+) (6), regenerating the mer coordination of the diphosphine. The hydride ion also breaks the chloride bridge of 3. The addition of KH to 3 leads to 1, closing a cycle for the formation of H2. Complex 1 reacts with a second hydride ion to give OsH4{xant(P(i)Pr2)2} (7) as consequence of the displacement of the chloride. Similarly to the latter, the oxygen atom of the mer-coordinated diphosphine of 7 has a tendency to be displaced by the hydride ion. Thus, the addition of KH to 7 yields [OsH5{xant(P(i)Pr2)2}](-) (8), containing a κ(2)-P,P-diphosphine. Complex 8 is easily protonated to afford OsH6{xant(P(i)Pr2)2} (9), which releases H2 to regenerate 7, closing a second cycle for the formation of molecular hydrogen.

  14. Substituent directed selectivity in anion recognition by a new class of simple osmium-pyrazole derived receptors.

    PubMed

    Das, Ankita; Mondal, Prasenjit; Dasgupta, Moumita; Kishore, Nand; Lahiri, Goutam Kumar

    2016-02-14

    The present article deals with the structurally, spectroscopically and electrochemically characterised osmium-bipyridyl derived complexes [(bpy)2Os(II)(HL1)Cl]ClO4 [1]ClO4 and [(bpy)2Os(II)(HL2)Cl]ClO4 [2]ClO4 incorporating neutral and monodentate pyrazole derivatives (HL) with one free NH function (bpy = 2,2'-bipyridine, HL1 = pyrazole, HL2 = 3,5-dimethylpyrazole). The crystal structures of [1]ClO4 and [2]ClO4 reveal intramolecular hydrogen bonding interactions between the free NH proton of HL and the equatorially placed Cl(-) ligand (N-HCl) with donor-acceptor distances of 3.114(7) Å and 3.153(6) Å as well as intermolecular hydrogen bonding interactions between the NH proton and one of the oxygen atoms of ClO4(-) (N-HO) with donor-acceptor distances of 2.870(10) Å and 3.024(8) Å, respectively. The effect of hydrogen bonding interactions has translated into the less acidic nature of the NH proton of the coordinated HL with estimated pKa > 12. 1(+) and 2(+) exhibit reversible Os(II)/(III) and irreversible Os(III)/(IV) processes in CH3CN within ± 2.0 V versus SCE. The effect of 3,5-dimethyl substituted HL2 on 2(+) has been reflected in the appreciable lowering (40 mV) of the Os(II/III) potential, along with the further decrease in the acidity of the NH proton (pKa > 13.0) with regard to HL1 coordinated 1(+) (pKa: ∼ 12.3). The electronic spectral features of Os(ii) (1(+)/2(+)) and electrochemically generated Os(III) (1(2+)/2(2+)) derived complexes have been analysed by TD-DFT calculations. The efficacy of the 1(+) and 2(+) encompassing free NH proton towards the anion recognition process has been evaluated by different experimental investigations using a wide variety of anions. It however establishes that receptor 1(+) can recognise both F(-) and OAc(-) in acetonitrile solution, while 2(+) is exclusively selective for the F(-) ion.

  15. A rise of atmospheric oxygen triggered by the Paleoproterozoic deglaciations: Insights from redox-sensitive elements and osmium isotopes

    NASA Astrophysics Data System (ADS)

    Goto, K. T.; Sekine, Y.; Suzuki, K.; Tajika, E.; Senda, R.; Nozaki, T.; Tada, R.; Goto, K.; Yamamoto, S.

    2010-12-01

    Paleoproterozoic is one of the most interesting periods in Earth’s history for our understanding of the interactions between the evolution of Earth’s system and early life. A number of geological evidence suggest that atmospheric oxygen rose dramatically during the Paleoproterozoic as a result of the photosynthetic production of oxygen (the Great Oxidation Event (GOE)). Because repeated severe glaciations occurred at the time of the GOE, climate change in the aftermath of these glaciations would have played a key role for the rise of atmospheric oxygen. However, because of lack of detailed geochemical records constraining the redox conditions in the atmosphere and oceans during and after the glaciations, the relationship between the GOE and the Paleoproterozoic glaciations is still poorly understood. Here we investigate the evolution of the redox conditions in the atmosphere and oceans based on both the isotopic compositions of osmium (Os) and the abundances of redox-sensitive elements such as rhenium (Re), molybdenum (Mo), uranium (U) and vanadium (V) in the sedimentary rocks deposited during and immediately after the first and second glaciations in the Huronian Supergroup, Canada. We found the remarkable enrichments of Re and Os in the sedimentary rocks deposited in the both glacial aftermath, suggesting that the redox conditions in the oceans were drastically changed in response to climate recovery. We also found the high initial 187Os/188Os ratios, up to 1.2, in the sedimentary rocks characterized by the enrichments of Os, suggesting that significant increases in the input of radiogenic Os from the continents. Taking into account that mobilization of Re and Os in the hydrological cycle requires moderately oxic conditions, our findings suggest that the atmosphere and shallow oceans have become moderately oxic immediately after both of the glaciations, possibly due to high levels of photosynthetic production. Although the similar nature of oxidation is

  16. Osmium Isotope Constraints on the Proportion of Bolide Component in Chicxulub Impact Melts

    NASA Technical Reports Server (NTRS)

    Gelinas, A.; Walker, R. J.; Kring, D. A.; Zurcher, L.

    2003-01-01

    Recent drilling has produced the samples of impact melt breccias examined here. All samples examined here are from the YAX-1 borehole [7]. Two main types of impact breccias have been studied. The first type is a green altered impact meltrock found in the lower portion of the impact sequence. The texture of the rock is microcrystalline and is composed of pyroxene, plagioclase, and alkali feldspars. Its composition is consistent with continental margin rocks. It is generally massive with some flow structure. The rock was brecciated and altered after solidfication and contains small amounts of both shocked and unshocked clasts of the impacted lithologies. These lithologies include lithic quartzite, and isolated feldspar crystals. The compositions of these rocks are similar to those seen in meltrocks sampled by the Yucatan-6 borehole [8-9]. Our study includes samples YAX-1_861.4, YAX-1_863.51, and YAX- 1_876.46, which represent both the top and lower portion of the green impact meltrock. The middle sample in the sequence has the least amount of (mineralogical) alteration [10]. The second type of melt breccia under study is a brown altered impact meltrock. It also has a microcrystalline texture and both shocked and unshocked clasts of the target material. Even though this rock type has been altered, remnant schleiren, metaquartzite, and micritic calcite have been identified. Sample YAX-1_841.32 is representative of this type of rock. It was recovered from a polymict breccia in the middle of the impact sequence.

  17. The 18.6-year lunar nodal cycle and surface temperature variability in the northeast Pacific

    NASA Astrophysics Data System (ADS)

    McKinnell, Stewart M.; Crawford, William R.

    2007-02-01

    The 18.6-year lunar nodal cycle (LNC) is a significant feature of winter (January) air and sea temperatures along the North American west coast over a 400-year period. Yet much of the recent temperature variation can also be explained by wind patterns associated with the PNA teleconnection. At Sitka, Alaska, (57°N) and nearby stations in northern British Columbia, the January PNA index accounts for over 70% of average January air temperatures in lengthy meteorological records. It appears that the LNC signal in January air temperatures in this region is not independent of the PNA, but is a component of it. The Sitka air temperature record, along with SSTs along the British Columbia coast and the PNA index have significant cross-correlations with the LNC that appear at a 2-year lag, LNC leading. The influence of the PNA pattern declines in winter with decreasing latitude but the LNC component does not. It appears as a significant feature of long-term SST variation at Scripps Pier and the California Current System. The LNC also appears over centennial-scales in proxy temperatures along western North America. The linkage of LNC-moderated surface temperatures to processes involving basin-scale teleconnections expands the possibility that the proximate mechanism may be located remotely from its expression in the northeast Pacific. Some of the largest potential sources of a diurnal tidal signal in the atmosphere are located in the western Pacific; the Sea of Okhotsk and the Indonesian archipelago.

  18. Triaxial rotor model description of E2 properties in {sup 186,188,190,192}Os

    SciTech Connect

    Allmond, J. M.; Zaballa, R.; Oros-Peusquens, A. M.; Kulp, W. D.; Wood, J. L.

    2008-07-15

    The triaxial rotor model with independent inertia and electric quadrupole tensors is applied to the description of the extensive set of E2 matrix elements available for {sup 186,188,190,192}Os. Most large and medium transition E2 matrix elements can be reproduced to within {approx}10%, and most diagonal elements to within {approx}30%. Most small transition matrix elements can be reproduced to within {approx}30%, and they support the interference effect exhibited by the model between the inertia and E2 tensors: this is a new feature of quantum rotor models. The diagonal E2 matrix elements at higher spins in the K=2 band are extremely sensitive to admixtures of higher K values: the low experimental values in {sup 190,192}Os indicate significant admixtures of K=4 components. Attention is given to the K{sup {pi}}=4{sup +} bands in these nuclei and the controversial issue of whether they are of quadrupole or hexadecapole nature.

  19. A triplet of differently shaped spin-zero states in the atomic nucleus 186Pb

    PubMed

    Andreyev; Huyse; Van Duppen P; Weissman; Ackermann; Gerl; Hessberger; Hofmann; Kleinbohl; Munzenberg; Reshitko; Schlegel; Schaffner; Cagarda; Matos; Saro; Keenan; Moore; O'Leary; Page; Taylor; Kettunen; Leino; Lavrentiev; Wyss; Heyde

    2000-05-25

    Understanding the fundamental excitations of many-fermion systems is of significant current interest. In atomic nuclei with even numbers of neutrons and protons, the low-lying excitation spectrum is generally formed by nucleon pair breaking and nuclear vibrations or rotations. However, for certain numbers of protons and neutrons, a subtle rearrangement of only a few nucleons among the orbitals at the Fermi surface can result in a different elementary mode: a macroscopic shape change. The first experimental evidence for this phenomenon came from the observation of shape coexistence in 16O (ref. 4). Other unexpected examples came with the discovery of fission isomers and super-deformed nuclei. Here we find experimentally that the lowest three states in the energy spectrum of the neutron deficient nucleus 186Pb are spherical, oblate and prolate. The states are populated by the alpha-decay of a parent nucleus; to identify them, we combine knowledge of the particular features of this decay with sensitive measurement techniques (a highly efficient velocity filters with strong background reduction, and an extremely selective recoil-alpha-electron coincidence tagging methods). The existence of this apparently unique shape triplet is permitted only by the specific conditions that are met around this particular nucleus.

  20. The fusion-fission process in the reaction 34S +186W near the interaction barrier

    NASA Astrophysics Data System (ADS)

    Harca, I. M.; Dmitriev, S.; Itkis, J.; Kozulin, E. M.; Knyazheva, G.; Loktev, T.; Novikov, K.; Azaiez, F.; Gottardo, A.; Matea, I.; Verney, D.; Chubarian, G.; Hanappe, F.; Piot, J.; Schmitt, C.; Trzaska, W. H.; Vardaci, E.

    2015-02-01

    The reaction 34S +186W at Elab=160 MeV was investigated with the aim of diving into the features of the fusion-fission process. Gamma rays in coincidence with binary reaction fragments were measured using the high efficiency gamma-ray spectrometer ORGAM at the TANDEM Accelerator facility of I.P.N., Orsay, and the time-of-flight spectrometer for fission fragments (FF) registration CORSET of the Flerov Laboratory of Nuclear Reactions (FLNR), Dubna. The coupling of the ORGAM and CORSET setups offers the unique opportunity of extracting details for characterizing the fusion-fission process and gives information regarding production of neutron-rich heavy nuclei. The FF-γ coincidence method is of better use then the γ - γ coincidence method when dealing with low statistic measurements and also offers the opportunity to precisely correct the Dopler shift for in-flight emitted gamma rays. Evidence of symmetric and asymmetric fission modes were observed in the mass and TKE distributions, occurring due to shell effects in the fragments. Coincident measurements allow for discrimination between the gamma rays by accepting a specific range within the mass distribution of the reaction products. Details regarding the experimental setup, methods of processing the acquisitioned data and preliminary results are presented.

  1. A high stellar velocity dispersion for a compact massive galaxy at redshift z = 2.186.

    PubMed

    van Dokkum, Pieter G; Kriek, Mariska; Franx, Marijn

    2009-08-06

    Recent studies have found that the oldest and most luminous galaxies in the early Universe are surprisingly compact, having stellar masses similar to present-day elliptical galaxies but much smaller sizes. This finding has attracted considerable attention, as it suggests that massive galaxies have grown in size by a factor of about five over the past ten billion years (10 Gyr). A key test of these results is a determination of the stellar kinematics of one of the compact galaxies: if the sizes of these objects are as extreme as has been claimed, their stars are expected to have much higher velocities than those in present-day galaxies of the same mass. Here we report a measurement of the stellar velocity dispersion of a massive compact galaxy at redshift z = 2.186, corresponding to a look-back time of 10.7 Gyr. The velocity dispersion is very high at km s(-1), consistent with the mass and compactness of the galaxy inferred from photometric data. This would indicate significant recent structural and dynamical evolution of massive galaxies over the past 10 Gyr. The uncertainty in the dispersion was determined from simulations that include the effects of noise and template mismatch. However, we cannot exclude the possibility that some subtle systematic effect may have influenced the analysis, given the low signal-to-noise ratio of our spectrum.

  2. Challenging fission dynamics around the barrier: The case of 34S + 186W

    NASA Astrophysics Data System (ADS)

    Kozulin, E. M.; Vardaci, E.; Harca, I. M.; Schmitt, C.; Itkis, I.; Knyazheva, G.; Novikov, K.; Bogachev, A.; Dmitriev, S.; Loktev, T.; Azaiez, F.; Matea, I.; Verney, D.; Gottardo, A.; Dorvaux, O.; Piot, J.; Chubarian, G.; Trzaska, W. H.; Hanappe, F.; Borcea, C.; Calinescu, S.; Petrone, C.

    2016-09-01

    The current status of fission dynamics studies in heavy-ion collisions around the Coulomb barrier is illustrated with the 34S + 186W reaction. The fission-fragment mass and total kinetic energy were measured at the ALTO facility at IPN Orsay, France, with a dedicated set-up using the ( v, E) approach. The measurement reveals the presence of an asymmetric fission component on top of a predominantly symmetric distribution. The asymmetric structure, pointed out for the first time, is discussed along with results of previous experiments studying the same reaction. While these analyses suggested the contribution from either quasi-fission or pre-equilibrium fission, we offer an alternative interpretation, in terms of shell-driven compound-nucleus fission. The present measurement demonstrates the critical influence of resolution when addressing puzzling cases, situated at the crossroads of the various channels opened in a heavy-ion collision. Current status in the field clearly calls for innovative measurements involving manifold correlations and new observables. The outcome of the attempt done in this work in this direction, based on the coincident measurement of prompt γ-rays is reported, and encouraging perspectives are discussed.

  3. Monometallic osmium(II) complexes with bis(N-methylbenzimidazolyl)benzene or -pyridine: a comparison study with ruthenium(II) analogues.

    PubMed

    Shao, Jiang-Yang; Zhong, Yu-Wu

    2013-06-03

    Seven bis-tridentate osmium complexes with Mebib or Mebip (Mebib is the 2-deprotonated form of 1,3-bis(N-methylbenzimidazolyl)benzene and Mebip is bis(N-methylbenzimidazolyl)pyridine) have been prepared, and their electrochemical and spectroscopic properties are compared with ruthenium structural analogues. Among them, four complexes have the [Os(NCN)(NNN)]-type coordination, including [Os(Mebib)(Mebip)](PF6)2 (1(PF6)2), [Os(dpb)(Mebip)](PF6) (2(PF6), dpb is the 2-deprotonated form of 1,3-di(pyrid-2-yl)benzene), [Os(Mebib)(ttpy)](PF6) (3(PF6), ttpy = 4'-tolyl-2,2':6',2"-terpyridine), and [Os(dpb)(ttpy)](PF6) (4(PF6)). The other three complexes are [Os(Mebip)2](PF6)2 (5(PF6)2), [Os(Mebip)(tpy)](PF6)2 (6(PF6)2, tpy = 2,2':6',2"-terpyridine), and [Os(ttpy)2](PF6)2 (7(PF6)2) with the [Os(NNN)(NNN)]-type coordination. Single crystals of 2(PF6) and 6(PF6)2 have been obtained, and their structures are studied by X-ray crystallographic analysis. The Os(II/III) redox potentials of 1(PF6)2 to 7(PF6)2 progressively increase from +0.04, +0.23, +0.24, +0.36, +0.56, +0.79 to +0.94 V vs Ag/AgCl, which are 200-300 mV less positive relative to the Ru(II/III) potentials of their ruthenium counterparts. The highest occupied molecular orbital energy levels of 1(+)-7(2+) are calculated to vary in a descending order. The ruthenium and osmium complexes have singlet metal-to-ligand charge-transfer (MLCT) transitions of similar energies and band shapes, while the osmium complexes display additional (3)MLCT transitions in the lower-energy region. Complexes 6(PF6)2 and 7(PF6)2 emit weakly at 780 and 740 nm, respectively. Complex 1(PF6)2 was synthesized as the oxidized Os(III) salt because of the low Os(II/III) potential. The transformation of 1(2+) to 1(+) by chemical reduction or electrolysis led to the emergence of the (1)MLCT transitions in the visible region.

  4. Escape of unradiogenic osmium during sub-aerial lava degassing: Evidence from fumarolic deposits, Piton de la Fournaise, Réunion Island

    NASA Astrophysics Data System (ADS)

    Gannoun, Abdelmouhcine; Vlastélic, Ivan; Schiano, Pierre

    2015-10-01

    This study presents new Re-Os isotope and elemental data in gas condensates and corresponding lavas in order to examine the geochemical behavior of these two elements during magma degassing at Piton de la Fournaise, Réunion Island. Gas sublimates formed between 2007 and 2011 at temperature ranging from 400 to ca. 100 °C include Na-K sulfate (aphthitalite), Na sulfate (thenardite), Ca-Cu sulfate (e.g. gypsum), Ca-Mg-Al-Fe fluoride (e.g. ralstonite) and native sulfur. The high temperature deposits show trace element typical of volcanic gas with high enrichment in Re (24 to 79 ppb), almost two order of magnitude higher than the corresponding lavas but with Os abundances similar to those of the lavas (14-132 ppt). In contrast the Os contents of the low temperature fluoride deposits (13-77 ppb) are higher than any of the other condensates. The fluorides are also enriched in Re, albeit to lesser extent than Os (2.9-15.3 ppb). Based on high-temperature samples, the fluid/melt partition coefficients estimated for Re and Os are 100 ± 80 and 1 ± 2, respectively. Considering 1% of fluid loss, these partition coefficients translate into emanation coefficients of 0.50 (0.17-0.65) for Re and 0.01 (0-0.03) for Os. These results indicate that Re, unlike Os, is highly volatile at Piton de la Fournaise. Osmium isotopic compositions of samples collected at medium and low temperature (<350 °C) are very uniform and unfractionated (187Os/188Os between 0.130-0.135) and plot within the range of the April 2007 lava flow and the historical lavas of Piton de la Fournaise (i.e. 0.130-0.137). However the highest temperature condensates (Na-K sulfates with T of 384-400°C) yield lower 187Os/188Os ratios (i.e. 0.124-0.129) within the field of mantle signal. Such unradiogenic compositions are best explained if old mantle sulfides occur in lavas and contribute to volcanic gases. Within the general frame of osmium mantle geochemistry, loss of unradiogenic Os during magmas degassing could help

  5. A Comparison of Modifications to MELCOR versions 1.8.2 and 1.8.6 for ITER Safety Analysis

    SciTech Connect

    B. J. Merrill; P. W. Humrickhouse

    2010-06-01

    During the Engineering Design Activity of the International Thermonuclear Experimental Reactor (ITER), the MELCOR 1.8.2 code was selected as one of several codes to be used to perform ITER safety analyses [1]. MELCOR was chosen because it has the capability of predicting coolant pressure, temperature, mass flow rate, and radionuclide and aerosol transport in nuclear facilities and reactor cooling systems. MELCOR can also predict structural temperatures (e.g. first wall, blanket, divertor, and vacuum vessel) resulting from energy produced by radioactive decay heat and/or chemical reactions (oxidation). The Idaho National Laboratory (INL) Fusion Safety Program (FSP) made fusion specific modifications to the MELCOR 1.8.2 code [2-6], including models for water freezing, air condensation, beryllium, carbon, and tungsten oxidation in steam and air environments, flow boiling in coolant loops, and radiation in enclosures, that allowed MELCOR to assess the thermal hydraulic response of ITER cooling systems and the transport of radionuclides as aerosols during accident conditions. Recently, the ITER International Organization (IO) used a “pedigreed” version of MELCOR 1.8.2 [7] to perform accident analyses for ITER’s “Rapport Préliminaire de Sûreté” (Report Preliminary on Safety - RPrS). The MELCOR thermal-hydraulics code [8] is currently under development at the Sandia National Laboratory (SNL) for the US Nuclear Regulatory Commission (NRC). MELCOR is used to model the progression of severe accidents in light water fission reactors. Because MELCOR has undergone many improvements between version 1.8.2 and 1.8.6, the INL FSP decided to introduce fusion modifications into MELCOR 1.8.6, and thereby produce a version of MELCOR 1.8.6 with similar capabilities to the pedigreed version of MELCOR 1.8.2 used for the ITER RPrS. We have applied this version of MELCOR 1.8.6 to the same set of problems used in the MELCOR 1.8.2 pedigree analysis [7]. Section 2 describes a non

  6. Oxidative Cyclization of 1,5-Dienes with Hydrogen Peroxide Catalyzed by an Osmium(III) Complex: Synthesis of cis-Tetrahydrofurans.

    PubMed

    Sugimoto, Hideki; Kanetake, Takayuki; Maeda, Kazuki; Itoh, Shinobu

    2016-03-18

    Stereoselective oxidative cyclization of 1,5-dienes with hydrogen peroxide catalyzed by [Os(III)(OH)(H2O)(L-N4Me2)](PF6)2 (1: L-N4Me2 = N,N'-dimethyl-2,11-diaza-[3,3](2,6)pyridinophane) is explored. 1,5-Dienes involving geraniol derivatives are converted to the corresponding tetrahydrofurans in modest to high yields. The products exclusively have the cis-conformation with respect to the substituents at the 2- and 5-positions of the tetrahydrofuran ring. The products also have a syn-conformation with respect to the furan oxygen atom and the hydroxyl groups. Mechanistic studies including a direct reaction of the oxo-hydroxo-osmium(V) complex, 2, with a dihydroxylated geraniol derivative are performed.

  7. Studies on the fine structural localization of zinc iodide-osmium reaction in the brain. III. Some characteristics of localization in the synaptosomes.

    PubMed

    Halász, N; Joó, F; Karnushina, I

    1978-02-01

    Synaptosomes from rat cerebral cortex were impregnated in the zinc iodide--osmium (ZIO) solution. The fine structural localization of the ZIO impregnation product was studied and, in addition, the function-dependent features of the reaction were examined after electrical stimulation or potassium chloride treatment. It was revealed that: (i) Aldehyde prefixation resulted in an increase in the number of reactive synaptic vesicles in all types of synaptosomes; (ii) Electrical stimulation decreased the number of reactive vesicles in a voltage dependent manner; (iii) Potassium chloride treatment also reduced the reactivity of vesicles; the reduction was dependent on the concentration of potassium and duration of treatment; (iv) Experimental interventions leading to the release of neurotransmitters from the synaptic vesicles and to fatigue of the nerve terminals also resulted in a decrease of the ZIO-reaction product of synaptic vesicles in a manner proportional to the strength of stimuli.

  8. Osmium(III) analogues of KP1019: electrochemical and chemical synthesis, spectroscopic characterization, X-ray crystallography, hydrolytic stability, and antiproliferative activity.

    PubMed

    Kuhn, Paul-Steffen; Büchel, Gabriel E; Jovanović, Katarina K; Filipović, Lana; Radulović, Siniša; Rapta, Peter; Arion, Vladimir B

    2014-10-20

    A one-electron reduction of osmium(IV) complexes trans-[Os(IV)Cl4(Hazole)2], where Hazole = 1H-pyrazole ([1](0)), 2H-indazole ([2](0)), 1H-imidazole ([3](0)), and 1H-benzimidazole ([4](0)), afforded a series of eight new complexes as osmium analogues of KP1019, a lead anticancer drug in clinical trials, with the general formula (cation)[trans-Os(III)Cl4(Hazole)2], where cation = H2pz(+) (H2pz[1]), H2ind(+) (H2ind[2]), H2im(+) (H2im[3]), Ph4P(+) (Ph4P[3]), nBu4N(+) (nBu4N[3]), H2bzim(+) (H2bzim[4]), Ph4P(+) (Ph4P[4]), and nBu4N(+) (nBu4N[4]). All complexes were characterized by elemental analysis, (1)H NMR spectroscopy, electrospray ionization mass spectrometry, UV-vis spectroscopy, cyclic voltammetry, while H2pz[1], H2ind[2], and nBu4[3], in addition, by X-ray diffraction. The reduced species [1](-) and [4](-) are stable in aqueous media in the absence of air oxygen and do not react with small biomolecules such as amino acids and the nucleotide 5'-dGMP. Cell culture experiments in five different human cancer cell lines (HeLa, A549, FemX, MDA-MB-453, and LS-174) and one noncancerous cell line (MRC-5) were performed, and the results were discussed and compared to those for KP1019 and cisplatin. Benzannulation in complexes with similar structure enhances antitumor activity by several orders of magnitude, implicating different mechanisms of action of the tested compounds. In particular, complexes H2ind[2] and H2bzim[4] exhibited significant antiproliferative activity in vitro when compared to H2pz[1] and H2im[3].

  9. Tris-bipyridine based dinuclear ruthenium(ii)-osmium(iii) complex dyads grafted onto TiO2 nanoparticles for mimicking the artificial photosynthetic Z-scheme.

    PubMed

    Favereau, Ludovic; Makhal, Abhinandan; Provost, David; Pellegrin, Yann; Blart, Errol; Göransson, Erik; Hammarström, Leif; Odobel, Fabrice

    2017-02-08

    The Z-Scheme function within molecular systems has been rarely reported for solar energy conversion although it offers the possibility to achieve higher efficiency than single photon absorber photosystems due to the use of a wider range of visible light. In this study, we synthesized and investigated the electrochemical and spectroscopic properties of two new dyads based on ruthenium and osmium tris-bipyridine complexes covalently linked via a butane bridge to explore their ability to realize the Z-scheme function once immobilized on TiO2. These dyads can be grafted onto a nanocrystalline TiO2 film via the osmium complex bearing two dicarboxylic acid bipyridine ligands, while the ruthenium complex contains either two unsubstituted bipyridine ancillary ligands (RuH-Os) or two (4,4'-bis-trifluoromethyl-bipyridine) ancillary ligands (RuCF3-Os). Transient absorption spectroscopy studies of the Ru(ii)-Os(iii) dyads with femtosecond and nanosecond lasers were conducted both in solution and on TiO2. For both conditions, the photophysical studies revealed that the MLCT excited state of the ruthenium complex is strongly quenched and predominantly decays by energy transfer to the LMCT of the adjacent Os(iii) complex, in spite of the high driving force for electron transfer. This unexpected result, which is in sharp contrast to previously reported Ru(ii)-Os(iii) dyads, precluded us to achieve the expected Z-scheme function. However, the above results may be a guide for designing new artificial molecular systems reproducing the complex function of a Z-scheme with molecular systems grafted onto a TiO2 mesoporous film.

  10. Evidence for 18.6 year Mn signal in temperature and drought conditions in North America since AD 1800

    NASA Astrophysics Data System (ADS)

    Currie, R. G.

    1981-11-01

    It is found that, since 1800, the mean discrepancy in epoch between maxima in temperature and maxima in the Drought Area Index (DAI) for the western United States with respect to maxima in the lunar modal tide is 0.9 and 0.1 year, respectively. It is suggested, in light of the fact that a cluster of nine stations in western Canada yields the 18.6-year lunar nodal term out of phase with 30 stations in eastern North America, that (1) enhanced drought conditions in the western United States are neither recurrent nor rhythmic on a time scale of 20 years, but rather periodic with a period of 18.6 years, and (2) the Rocky Mountain system is an influence for atmospheric tidal phenomena at epochs of maximum in the lunar nodal tide as well as for maxima in the temperature records of the DAI.

  11. Evidence for 18.6 year Mn signal in temperature and drought conditions in North America since AD 1800

    NASA Technical Reports Server (NTRS)

    Currie, R. G.

    1981-01-01

    It is found that, since 1800, the mean discrepancy in epoch between maxima in temperature and maxima in the Drought Area Index (DAI) for the western United States with respect to maxima in the lunar modal tide is 0.9 and 0.1 year, respectively. It is suggested, in light of the fact that a cluster of nine stations in western Canada yields the 18.6-year lunar nodal term out of phase with 30 stations in eastern North America, that (1) enhanced drought conditions in the western United States are neither recurrent nor rhythmic on a time scale of 20 years, but rather periodic with a period of 18.6 years, and (2) the Rocky Mountain system is an influence for atmospheric tidal phenomena at epochs of maximum in the lunar nodal tide as well as for maxima in the temperature records of the DAI.

  12. Rhenium - osmium heterogeneity of enriched mantle basalts explained by composition and behaviour of mantle-derived sulfides

    NASA Astrophysics Data System (ADS)

    Harvey, J.; Dale, C. W.; Gannoun, A.; Burton, K. W.

    2010-12-01

    Analyses of enriched mantle (EM) -basalts, using lithophile element-based isotope systems have long provided evidence for discrete, but variable mantle reservoirs [1]. Upon partial melting, the isotopic fingerprint of each reservoir is imparted upon the partial melt produced. However, recent work involving the Re-Os isotope systematics of EM-basalts [2] suggests that it may not be so simple to delimit these previously well defined mantle reservoirs; the “mantle zoo” [3] may contain more reservoirs than previously envisaged. However, a simple model, with varying contributions from two populations of compositionally distinct mantle sulfides can readily account for the observed heterogeneities in Re-Os isotope systematics of such basalts without additional mantle reservoirs. Rhenium-osmium elemental and isotopic analyses of individual sulfide grains separated from spinel lherzolites from Kilbourne Hole, NM, USA demonstrate that two discrete populations of mantle sulfide exist in terms of both Re-Os systematics and textural relationship with co-existing silicates. One population, with a rounded morphology, is preserved in silicate grains and typically possesses high [Os], low [Re] with unradiogenic, typically sub-chondritic, 187Os/188Os attributable to long term isolation in a low-Re environment. By contrast, irregular-shaped sulfides, preserved along silicate grain boundaries, possess low [Os], higher [Re] and a wider range of, but generally supra-chondritic, 187Os/188Os ([Os] typically ≤ 1-2 ppm, 187Os/188Os ≤ 0.3729; this study). This population is thought to represent metasomatic sulfide (e.g. [4,5]). Uncontaminated silicate phases contain negligible Os (<100 ppt) therefore the Os elemental and isotope composition of basalts is dominated by volumetrically insignificant sulfide ([Os] ≤ 37 ppm, this study). During the early stages of partial melting, supra-chondritic interstitial sulfides are mobilized and incorporated into the melt, adding their radiogenic

  13. Evaluation of the rhenium-osmium geochronometer in the Phosphoria petroleum system, Bighorn Basin of Wyoming and Montana, USA

    NASA Astrophysics Data System (ADS)

    Lillis, Paul G.; Selby, David

    2013-10-01

    Rhenium-osmium (Re-Os) geochronometry is applied to crude oils derived from the Permian Phosphoria Formation of the Bighorn Basin in Wyoming and Montana to determine whether the radiogenic age reflects the timing of petroleum generation, timing of migration, age of the source rock, or the timing of thermochemical sulfate reduction (TSR). The oils selected for this study are interpreted to be derived from the Meade Peak Phosphatic Shale and Retort Phosphatic Shale Members of the Phosphoria Formation based on oil-oil and oil-source rock correlations utilizing bulk properties, elemental composition, δ13C and δ34S values, and biomarker distributions. The δ34S values of the oils range from -6.2‰ to +5.7‰, with oils heavier than -2‰ interpreted to be indicative of TSR. The Re and Os isotope data of the Phosphoria oils plot in two general trends: (1) the main trend (n = 15 oils) yielding a Triassic age (239 ± 43 Ma) with an initial 187Os/188Os value of 0.85 ± 0.42 and a mean square weighted deviation (MSWD) of 1596, and (2) the Torchlight trend (n = 4 oils) yielding a Miocene age (9.24 ± 0.39 Ma) with an initial 187Os/188Os value of 1.88 ± 0.01 and a MSWD of 0.05. The scatter (high MSWD) in the main-trend regression is due, in part, to TSR in reservoirs along the eastern margin of the basin. Excluding oils that have experienced TSR, the regression is significantly improved, yielding an age of 211 ± 21 Ma with a MSWD of 148. This revised age is consistent with some studies that have proposed Late Triassic as the beginning of Phosphoria oil generation and migration, and does not seem to reflect the source rock age (Permian) or the timing of re-migration (Late Cretaceous to Eocene) associated with the Laramide orogeny. The low precision of the revised regression (±21 Ma) is not unexpected for this oil family given the long duration of generation from a large geographic area of mature Phosphoria source rock, and the possible range in the initial 187Os/188Os

  14. Evaluation of the rhenium-osmium geochronometer in the Phosphoria petroleum system, Bighorn Basin of Wyoming and Montana, USA

    USGS Publications Warehouse

    Lillis, Paul G.; Selby, David

    2013-01-01

    Rhenium-osmium (Re-Os) geochronometry is applied to crude oils derived from the Permian Phosphoria Formation of the Bighorn Basin in Wyoming and Montana to determine whether the radiogenic age reflects the timing of petroleum generation, timing of migration, age of the source rock, or the timing of thermochemical sulfate reduction (TSR). The oils selected for this study are interpreted to be derived from the Meade Peak Phosphatic Shale and Retort Phosphatic Shale Members of the Phosphoria Formation based on oil-oil and oil-source rock correlations utilizing bulk properties, elemental composition, δ13C and δ34S values, and biomarker distributions. The δ34S values of the oils range from -6.2‰ to +5.7‰, with oils heavier than -2‰ interpreted to be indicative of TSR. The Re and Os isotope data of the Phosphoria oils plot in two general trends: (1) the main trend (n = 15 oils) yielding a Triassic age (239 ± 43 Ma) with an initial 187Os/188Os value of 0.85 ± 0.42 and a mean square weighted deviation (MSWD) of 1596, and (2) the Torchlight trend (n = 4 oils) yielding a Miocene age (9.24 ± 0.39 Ma) with an initial 187Os/188Os value of 1.88 ± 0.01 and a MSWD of 0.05. The scatter (high MSWD) in the main-trend regression is due, in part, to TSR in reservoirs along the eastern margin of the basin. Excluding oils that have experienced TSR, the regression is significantly improved, yielding an age of 211 ± 21 Ma with a MSWD of 148. This revised age is consistent with some studies that have proposed Late Triassic as the beginning of Phosphoria oil generation and migration, and does not seem to reflect the source rock age (Permian) or the timing of re-migration (Late Cretaceous to Eocene) associated with the Laramide orogeny. The low precision of the revised regression (±21 Ma) is not unexpected for this oil family given the long duration of generation from a large geographic area of mature Phosphoria source rock, and the possible range in the initial 187Os/188Os

  15. Fibrin glue system for adjuvant brachytherapy of brain tumors with 188Re and 186Re-labeled microspheres.

    PubMed

    Häfeli, Urs O; Pauer, Gayle J; Unnithan, Jaya; Prayson, Richard A

    2007-03-01

    Brain tumors such as glioblastoma reappear in their original location in almost 50% of cases. To prevent this recurrence, we developed a radiopharmaceutical system that consists of a gel applied immediately after surgical resection of a brain tumor to deliver local radiation booster doses. The gel, which strongly adheres to tissue in the treatment area, consists of fibrin glue containing the beta-emitters rhenium-188 and rhenium-186 in microsphere-bound form. Such microspheres can be prepared by short (2 h or less) neutron activation even in low neutron flux reactors, yielding a mixture of the two beta-emitters rhenium-188 (E(max)=2.1 MeV, half life=17 h) and rhenium-186 (E(max)=1.1 MeV, half life=90.6h). The dosimetry of this rhenium-188/rhenium-186 fibrin glue system was determined using gafchromic film measurements. The treatment efficacy of the radioactive fibrin glue was measured in a 9L-glioblastoma rat model. All animals receiving the non-radioactive fibrin glue died within 17+/-3 days, whereas 60% of the treated animals survived 36 days, the final length of the experiment. Control animals that were treated with the same amount of radioactive fibrin glue, but had not received a previous tumor cell injection, showed no toxic effects over one year. The beta-radiation emitting rhenium-188/rhenium-186-based gel thus provides an effective method of delivering high doses of local radiation to tumor tissue, particularly to wet areas where high adhesive strength and long-term radiation (with or without drug) delivery are needed.

  16. Why the 18.6 year tide cannot explain the change of sign observed in j2

    NASA Astrophysics Data System (ADS)

    Deleflie, F.; Exertier, P.; Metris, G.; Berio, P.; Laurain, O.; Lemoine, J.-M.; Biancale, R.

    2003-06-01

    Recent studies show a change, starting in 1998, in the behavior of the variation of the dynamical flattening of the Earth (J2), supposed to be constant (secular), and mainly due to the post glacial rebound effect. In this paper, we study to what extent this behavior can be correlated or not with the 18.6 year tide: with more than twenty years of tracking data on LAGEOS-1, that is to say more than a period of 18.6 years, this effect can now be separated from the secular variation. We use our theory of mean orbital motion, dedicated to studies of the long period effects on the orbital motion. We build one single arc of LAGEOS-1 from 1980 to 2002, which provides a continuous description of the orbital parameters. This is the great originality of our approach. We focus our attention on the ascending node of LAGEOS-1, and we show that the change observed in j2 cannot be attributed to a statistical error due to a correlation, in short arcs results, between the secular variation of J2 and the 18.6 year tide. The proof is based on the adjustment of amplitudes and phases of the long period tides, and on the shape of the residuals.

  17. A DPYD variant (Y186C) in individuals of african ancestry is associated with reduced DPD enzyme activity.

    PubMed

    Offer, S M; Lee, A M; Mattison, L K; Fossum, C; Wegner, N J; Diasio, R B

    2013-07-01

    5-Fluorouracil (5-FU) is used to treat many aggressive cancers, such as those of the colon, breast, and head and neck. The responses to 5-FU, with respect to both toxicity and efficacy, vary among racial groups, potentially because of variability in the activity levels of the enzyme dihydropyrimidine dehydrogenase (DPD, encoded by the DPYD gene). In this study, the genetic associations between DPYD variations and circulating mononuclear-cell DPD enzyme activity were evaluated in 94 African-American and 81 European-American volunteers. The DPYD-Y186C variant was unique to individuals of African ancestry, and DPD activity was 46% lower in carriers as compared with noncarriers (279 ± 35 vs. 514 ± 168 pmol 5-FU min(-1) mg(-1); P = 0.00029). In this study, 26% of the African Americans with reduced DPD activity were carriers of Y186C. In the African-American cohort, after excluding Y186C carriers, homozygous carriers of C29R showed 27% higher DPD activity as compared with noncarriers (609 ± 152 and 480 ± 152 pmol 5-FU min(-1) mg(-1), respectively; P = 0.013).

  18. Cross sections for (n, 2n), (n, p) and (n, ) reactions on osmium isotopes in the neutron energy range of 13.5-14.8 MeV.

    PubMed

    Zhao, Liangyong; Yuan, Jilong; Tuo, Fei; Zhang, Yanbin; Kong, Xiangzhong; Liu, Rong; Jiang, Li

    2008-10-01

    Cross sections for (n, 2n), (n, p) and (n, alpha) reactions on the osmium isotopes were measured in the neutron energies 13.5-14.8 MeV by the activation technique with the monitor reaction (93)Nb(n, 2n)(92 m)Nb. Our measurements were carried out by gamma-detection using a coaxial high-purity germanium (HPGe) detector. Natural high-purity osmium powder (99.9%) was fabricated as the samples. The neutron energies were determined by the cross-section ratios for (93)Nb(n, 2n)(92 m)Nb and (90)Zr(n, 2n)(89 m+g)Zr reactions. The fast neutrons were produced by the T(d, n)(4)He reaction. The results obtained were compared with previous data.

  19. Binding of an organo-osmium(II) anticancer complex to guanine and cytosine on DNA revealed by electron-based dissociations in high resolution Top-Down FT-ICR mass spectrometry.

    PubMed

    Wootton, Christopher A; Sanchez-Cano, Carlos; Liu, Hong-Ke; Barrow, Mark P; Sadler, Peter J; O'Connor, Peter B

    2015-02-28

    The Os(II) arene anticancer complex [(η(6)-bip)Os(en)Cl](+) (Os1-Cl; where bip = biphenyl, and en = ethylenediamine) binds strongly to DNA. Here we investigate reactions between Os1-Cl and the self-complementary 12-mer oligonucleotide 5'-TAGTAATTACTA-3' (DNA12) using ultra high resolution Fourier Transform-Ion Cyclotron Resonance Mass Spectrometry (FT-ICR MS). Identification of the specific sites of DNA osmiation with {(η(6)-bip)Os(en)}(2+) was made possible by the use of Electron Detachment Dissociation (EDD) which produced a wide range of assignable osmiated MS/MS fragments. In contrast, the more commonly used CAD and IRMPD techniques produced fragments which lose the bound osmium. These studies reveal that not only is guanine G3 a strong binding site for {(η(6)-bip)Os(en)}(2+) but, unexpectedly, so too is cytosine C10. Interestingly, the G3/C10 di-osmiated adduct of DNA12 also formed readily but did not undergo such facile fragmentation by EDD, perhaps due to folding induced by van der Waal's interactions of the bound osmium arene species. These new insights into osmium arene DNA adducts should prove valuable for the design of new organometallic drugs and contribute to understanding the lack of cross resistance of this organometallic anticancer complex with cisplatin.

  20. Synthesis, crystal structure, and magnetic properties of Li3Mg2OsO6, a geometrically frustrated osmium(V) oxide with an ordered rock salt structure: comparison with isostructural Li3Mg2RuO6.

    PubMed

    Nguyen, Phuong-Hieu T; Ramezanipour, Farshid; Greedan, John E; Cranswick, Lachlan M D; Derakhshan, Shahab

    2012-11-05

    The novel osmium-based oxide Li(3)Mg(2)OsO(6) was synthesized in polycrystalline form by reducing Li(5)OsO(6) by osmium metal and osmium(IV) oxide in the presence of stoichiometric amounts of magnesium oxide. The crystal structure was refined using powder X-ray diffraction data in the orthorhombic Fddd space group with a = 5.88982(5) Å, b = 8.46873(6) Å, and c = 17.6825(2) Å. This compound is isostructural and isoelectronic with the ruthenium-based system Li(3)Mg(2)RuO(6). The magnetic ion sublattice Os(5+) (S = 3/2) consists of chains of interconnected corner- and edge-shared triangles, which brings about the potential for geometric magnetic frustration. The Curie-Weiss law holds over the range 80-300 K with C = 1.42(3) emu·K/mol [μ(eff) = 3.37(2) μ(B)] and θ(C) = -105.8(2) K. Below 80 K, there are three anomalies at 75, 30, and 8 K. Those at 75 and 30 K are suggestive of short-range antiferromagnetic correlations, while that at 8 K is a somewhat sharper maximum showing a zero-field-cooled/field-cooled divergence suggestive of perhaps spin freezing. The absence of magnetic Bragg peaks at 3.9 K in the neutron diffraction pattern supports this characterization, as does the absence of a sharp peak in the heat capacity, which instead shows only a very broad maximum at ∼12 K. A frustration index of f = 106/8 = 13 indicates a high degree of frustration. The magnetic properties of the osmium phase differ markedly from those of the isostructural ruthenium material, which shows long-range antiferromagnetic order below 17 K, f = 6, and no unusual features at higher temperatures. Estimates of the magnetic exchange interactions at the level of spin-dimer analysis for both the ruthenium and osmium materials support a more frustrated picture for the latter. Errors in the calculation and assignment of the exchange pathways in the previous report on Li(3)Mg(2)RuO(6) are identified and corrected.

  1. The CORM ALF-186 Mediates Anti-Apoptotic Signaling via an Activation of the p38 MAPK after Ischemia and Reperfusion Injury in Retinal Ganglion Cells

    PubMed Central

    Ulbrich, Felix; Kaufmann, Kai B.; Meske, Alexander; Lagrèze, Wolf A.; Augustynik, Michael; Buerkle, Hartmut; Ramao, Carlos C.; Biermann, Julia

    2016-01-01

    Purpose Ischemia and reperfusion injury may induce apoptosis and lead to sustained tissue damage and loss of function, especially in neuronal organs. While carbon monoxide is known to exert protective effects after various harmful events, the mechanism of carbon monoxide releasing molecules in neuronal tissue has not been investigated yet. We hypothesize that the carbon monoxide releasing molecule (CORM) ALF-186, administered after neuronal ischemia-reperfusion injury (IRI), counteracts retinal apoptosis and its involved signaling pathways and consecutively reduces neuronal tissue damage. Methods IRI was performed in rat´s retinae for 1 hour. The water-soluble CORM ALF-186 (10 mg/kg) was administered intravenously via a tail vein after reperfusion. After 24 and 48 hours, retinal tissue was harvested to analyze mRNA and protein expression of Bcl-2, Bax, Caspase-3, ERK1/2, p38 and JNK. Densities of fluorogold pre-labeled retinal ganglion cells (RGC) were analyzed 7 days after IRI. Immunohistochemistry was performed on retinal cross sections. Results ALF-186 significantly reduced IRI mediated loss of RGC. ALF-186 treatment differentially affected mitogen-activated protein kinases (MAPK) phosphorylation: ALF-186 activated p38 and suppressed ERK1/2 phosphorylation, while JNK remained unchanged. Furthermore, ALF-186 treatment affected mitochondrial apoptosis, decreasing pro-apoptotic Bax and Caspase-3-cleavage, but increasing anti-apoptotic Bcl-2. Inhibition of p38-MAPK using SB203580 reduced ALF-186 mediated anti-apoptotic effects. Conclusion In this study, ALF-186 mediated substantial neuroprotection, affecting intracellular apoptotic signaling, mainly via MAPK p38. CORMs may thus represent a promising therapeutic alternative treating neuronal IRI. PMID:27764224

  2. High-resolution spectroscopy and analysis of the ν1/ν3 stretching dyad of osmium tetroxide

    NASA Astrophysics Data System (ADS)

    Louviot, M.; Boudon, V.; Manceron, L.; Roy, P.; Balcon, D.

    2012-01-01

    OsO4 is a heavy tetrahedral molecule that may constitute a benchmark for quantum chemistry calculations. Its favorable spin statistics (due to the zero nuclear spin of oxygen atoms) is such that only A1 and A2 rovibrational levels are allowed, leading to a dense, but quite easily resolved spectrum. Most lines are single ones, instead of complex line clusters as in the case of other heavy spherical-tops like SF6, for instance. It is thus possible to fully assign and fit the spectrum and to obtain precise experimental effective molecular parameters. The strong ν3 stretching fundamental has been studied a long time ago as an isolated band [McDowell RS, Radziemski LJ, Flicker H, Galbraith HW, Kennedy RC, Nereson NG, et al. Journal of Chemical Physics 1978;88:1513-21; Bobin B, Valentin A, Henry L. Journal of Molecular Spectroscopy 1987;122:229-41]. We reinvestigate here this region and perform new assignments and effective Hamiltonian parameter fits for the four main isotopologues (192OsO4, 190OsO4, 189OsO4, 188OsO4), by considering the ν1/ν3 stretching dyad. A new experimental spectrum has been recorded at room temperature, thanks to a Bruker IFS 125 HR interferometer and using a natural abundance OsO4 sample. Assignments and analyses were performed thanks to the SPVIEW and XTDS softwares, respectively [Wenger Ch, Boudon V, Rotger M, Sanzharov M, Champion J-P. Journal of Molecular Spectroscopy 2008;251:102-13]. We provide precise effective Hamiltonian parameters, including band centers and Coriolis interaction parameters. We discuss isotopic shifts and estimate the band centers for the three minor isotopologues (187OsO4, 186OsO4, 184OsO4). The Q branches of the first two of them are clearly identified in the experimental spectrum.

  3. Evidence for 18.6-year lunar nodal drought in Western North America during the past millennium

    NASA Astrophysics Data System (ADS)

    Currie, Robert G.

    1984-02-01

    Analysis of 38 tree ring chronologies yields evidence for enhanced drought conditions every 18.6 years in the North American interior for the past millenium. Cross spectra between a drought area index and 26 temperature records confirm the analysis of Currie (1979, 1981d) as regards a lunar nodal MN term in these data. Discussion of the MN tidal constituent, which appreciably modulate amplitude and phase of four main constituents (M2, K1, O1, Mf), is presented, and implications for agriculture are surveyed.

  4. Flight evaluation of HL-10 lifting body handling qualities at Mach numbers from 0.30 to 1.86

    NASA Technical Reports Server (NTRS)

    Kempel, R. W.; Manke, J. A.

    1974-01-01

    The longitudinal and lateral-directional handling qualities of the HL-10 lifting body vehicle were evaluated in flight at Mach numbers up to 1.86 and altitudes up to approximately 27,450 meters (90,000 feet). In general, the vehicle's handling qualities were considered to be good. Approximately 91 percent of the pilot ratings were 3.5 or better, and 42.4 percent were 2.0. Handling qualities problems were encountered during the first flight due to problems with the control system and vehicle aerodynamics. Modifications of the flight vehicle corrected all deficiencies, and no other significant handling qualities problems were encountered.

  5. Installation Restoration Program. Preliminary Assessment: 186th Tactical Reconnaissance Group, Mississippi Air National Guard, Meridian Airport, Key Field, Meridian, Mississippi

    DTIC Science & Technology

    1988-10-01

    INSTALLATION RESTORATION PROGRAM 040 In PRELIMINARY ASSESSMENTMvGo 186th Tactical Reconnaissance Group * Mississippi Air National Guard Meridian...Martin Marietta &Mergy py~sti, Inc. for the purpose of aiding in the inplsentation for the Air Force Installationi Restoration Program- Copies of the... Techinical Inforviation Center Cammron Station Alexandria, Virginia 22314 BPAz am= "EORT OCjQc E TA,’ ,., J :AGE , ,r.oo. * ,,wr~:Th.C~~t. S r ’.tArO .0’r~l

  6. Remote impacts of the 18.6 year period modulation of localized tidal mixing in the North Pacific

    NASA Astrophysics Data System (ADS)

    Osafune, S.; Yasuda, I.

    2013-06-01

    The impact of the 18.6 year period modulation of the localized strong tidal mixing on the annual mean sea surface temperature (SST) in the open North Pacific Ocean is analyzed in a numerical experiment using an ocean general circulation model. Oscillatory SST anomalies induced in this model move eastward along the boundary between the subarctic and the subtropical gyres from the western boundary to the central Pacific in about 10 years, with a speed slower than that of the surface currents. Anomalous currents in the upper 300 m play an important role in inducing SST anomalies. These anomalous currents are coupled to subsurface density anomalies and could be related to eastward moving, low-mode (second or higher), baroclinic long Rossby waves. These results suggest that the 18.6 year modulation of localized strong tidal mixing can influence large-scale SST and/or heat flux, and thus climate, as a result of remote impacts associated with changes in the mid-depth density structure, induced locally where mixing is strong, that move horizontally into the open ocean.

  7. Observations of the 18.6-year cycle effects on the sea-level oscillations in the North Atlantic Ocean

    NASA Astrophysics Data System (ADS)

    Capuano, P.; De Lauro, E.; De Martino, S.; Falanga, M.

    2012-11-01

    We investigate the physical processes that generate the ocean tides, whose understanding has important influence on the marine activities. We analyze historical sea-level oscillations, continuously recorded from six stations in the North Atlantic Ocean spanning a time period of eighty years from 1926. In this paper, an Independent-Component-Analysis-based approach is adopted to obtain a clear identification of the main tidal constituents in term of waveform in time domain from the simultaneously recorded signals. This technique separates at most six nonlinear tidal components which are weakly superimposed. The fundamental objective is to extract information on the degree of complexity of the involved dynamics and on the very long-term tidal constituents. This is particularly significant to understand the response of the ocean to the tidal forcing. We put the emphasis on the near-bidecadal time scale and its influence on the short-periods tides. In details the Moon 18.6 y nodal cycle modulation acts in the ocean in quite an analogous manner to the fortnightly modulation in many shallow seas. Our results give new insights into the evidence for an 18.6 y effect in the climate/ocean variation whose physical mechanism details remain murky.

  8. Periodic (18.6-year) and cyclic (11-year) induced drought and flood in western North America

    NASA Astrophysics Data System (ADS)

    Currie, Robert Guinn

    1984-08-01

    Analysis of 102 reent tree-ring chronologies confirms earlier evidence for 18.6-year tidal drought/flood induction (Currie, 1981d, 1984b) and led to discovery of 11-year solar cycle induced drought/flood for western North America. Bistable phasing in terms of geography is found with epohs of maximum in lunar nodal 18.6-year drought in western Canada out of phase with those in the western United States and northern Mexico the past two centuries. Solar drought/flood induction provides one mechanism that appears to have modulated the intensity of nodal drought/flood induction in the latter region, most recently at epoch 1936.1. The above results were confirmed by analysis of yet more voluminous data, and they le to discovery of an example of bistable phasing with respect to time in western Canada during the 17th century. The implications for agriculture of such phenomena, which occur worldwide (Currie, 1984c), are surveyed.

  9. Covariances of Evaluated Nuclear Cross Section Data for (232)Th, (180,182,183,184,186)W and (55)Mn

    SciTech Connect

    Trkov, A.; Capote, R.; Soukhovitskii, E; Leal, Luiz C; Sin, M; Kodeli, I.; Muir, D W

    2011-01-01

    The EMPIRE code system is a versatile package for nuclear model calculations that is often used for nuclear data evaluation. Its capabilities include random sampling of model parameters, which can be utilized to generate a full covariance matrix of all scattering cross sections, including cross-reaction correlations. The EMPIRE system was used to prepare the prior covariance matrices of reaction cross sections of (232)Th, (180,182,183,184,186)W and (55)Mn nuclei for incident neutron energies up to 60 MeV. The obtained modeling prior was fed to the GANDR system, which is a package for a global assessment of nuclear data, based on the Generalized Least-Squares method. By introducing experimental data from the EXFOR database into GANDR, the constrained covariance matrices and cross section adjustment functions were obtained. Applying the correction functions on the cross sections and formatting the covariance matrices, the final evaluations in ENDF-6 format including covariances were derived. In the resonance energy range, separate analyses were performed to determine the resonance parameters with their respective covariances. The data files thus obtained were then subjected to detailed testing and validation. Described evaluations with covariances of (232)Th, (180,182,183,184,186)W and (55)Mn nuclei are included into the ENDF/B-VII.1 library release.

  10. Evaluated 182,183,184,186W Neutron Cross Sections and Covariances in the Resolved Resonance Region

    SciTech Connect

    Pigni, Marco T; Leal, Luiz C

    2015-01-01

    Oak Ridge National Laboratory (ORNL) has recently completed the resonance parameter evaluation of four tungsten isotopes, i.e., 182,183,184,186W, in the neutron energy range of thermal up to several keV. This nuclear data work was performed with support from the US Nuclear Criticality Safety Program (NCSP) in an effort to provide improved tungsten cross section and covariance data for criticality safety analyses. The evaluation methodology uses the Reich-Moore approximation of the R-matrix formalism of the code SAMMY to fit high-resolution measurements performed in 2010 and 2012 at the Geel linear accelerator facility (GELINA), as well as other experimental data sets on natural tungsten available in the EXFOR library. In the analyzed energy range, this work nearly doubles the resolved resonance region (RRR) present in the latest US nuclear data library ENDF/B-VII.1. In view of the interest in tungsten for distinct types of nuclear applications and the relatively homogeneous distribution of the isotopic tungsten—namely, 182W(26.5%), 183W(14.31%), 184W(30.64%), and 186W(28.43%) - the completion of these four evaluations represents a significant contribution to the improvement of the ENDF library. This paper presents an overview of the evaluated resonance parameters and related covariances for total and capture cross sections on the four tungsten isotopes.

  11. Dosimetric comparison of {sup 90}Y, {sup 32}P, and {sup 186}Re radiocolloids in craniopharyngioma treatments

    SciTech Connect

    Sadeghi, Mahdi; Karimi, Elham; Hosseini, S. Hamed

    2009-11-15

    Purpose: In the radionuclide treatment of some forms of brain tumors such as craniopharyngiomas, the selection of the appropriate radionuclide for therapy is a key element in treatment planning. The aim was to study the influence by considering the beta-emitter radionuclide dose rate in an intracranial cyst. Methods: Dosimetry was performed using the MCNP4C radiation transport code. Analytical dosimetry was additionally performed using the Loevinger and the Berger formulas in the MATLAB software. Each result was compared under identical conditions. The advantages and disadvantages of using {sup 90}Y versus {sup 32}P and {sup 186}Re were investigated. Results: The dose rate at the inner surface of the cyst wall was estimated to be 400 mGy/h for a 1 MBq/ml concentration of {sup 90}Y. Under identical conditions of treatment, the corresponding dose rates were 300 mGy/h for {sup 32}P and 160 mGy/h for {sup 186}Re. For a well-defined cyst radius and identical wall thickness, higher dose rates resulted for {sup 90}Y. Conclusions: To achieve the same radiological burden, the required amount of physical activity of injectable solution is lower for {sup 32}P. This is found to be a consequence of both the radionuclide physical half-life and the pattern of energy deposition from the emitted radiation. According to the half-life and dose-rate results, {sup 90}Y would be a good substitute for {sup 32}P.

  12. Covariances of Evaluated Nuclear Cross Section Data for 232Th, 180,182,183,184,186W and 55Mn

    NASA Astrophysics Data System (ADS)

    Trkov, A.; Capote, R.; Soukhovitskii, E. Sh.; Leal, L. C.; Sin, M.; Kodeli, I.; Muir, D. W.

    2011-12-01

    The EMPIRE code system is a versatile package for nuclear model calculations that is often used for nuclear data evaluation. Its capabilities include random sampling of model parameters, which can be utilised to generate a full covariance matrix of all scattering cross sections, including cross-reaction correlations. The EMPIRE system was used to prepare the prior covariance matrices of reaction cross sections of 232Th, 180,182,183,184,186W and 55Mn nuclei for incident neutron energies up to 60 MeV. The obtained modelling prior was fed to the GANDR system, which is a package for a global assessment of nuclear data, based on the Generalised Least-Squares method. By introducing experimental data from the EXFOR database into GANDR, the constrained covariance matrices and cross section adjustment functions were obtained. Applying the correction functions on the cross sections and formatting the covariance matrices, the final evaluations in ENDF-6 format including covariances were derived. In the resonance energy range, separate analyses were performed to determine the resonance parameters with their respective covariances. The data files thus obtained were then subjected to detailed testing and validation. Described evaluations with covariances of 232Th, 180,182,183,184,186W and 55Mn nuclei are included into the ENDF/B-VII.1 library release.

  13. Electron transfer from Proteus vulgaris to a covalently assembled, single walled carbon nanotube electrode functionalised with osmium bipyridine complex: application to a whole cell biosensor.

    PubMed

    Rawson, Frankie J; Garrett, David J; Leech, Donal; Downard, Alison J; Baronian, Keith H R

    2011-01-15

    We report the fabrication and use of electrodes constructed from single walled carbon nanotubes (SWCNTs) chemically assembled on a carbon surface and functionalised with an osmium(II) bipyridine complex (Osbpy). The ability of the electrodes to transduce biologically generated currents from Proteus vulgaris has been established. Our investigations show that there are two contributions to the current: one from electroactive species secreted into solution and another from cell redox sites. The modified electrode can be used to monitor cell metabolism, thereby acting as a whole cell biosensor. The biosensor was used in a 1-h assay to investigate the toxicity of ethanol, sodium azide and the antibiotic ampicillin and gave quantitative data that were closely correlated with standard cell plate viability assays. The results provide proof of principle that the whole cell biosensor could be used for high throughput screening of antimicrobial activity. One of the modified electrodes was used for approximately 1000 measurements over four months demonstrating the robustness of the system.

  14. Three-dimensional shape of the Golgi apparatus in different cell types: serial section scanning electron microscopy of the osmium-impregnated Golgi apparatus.

    PubMed

    Koga, Daisuke; Kusumi, Satoshi; Ushiki, Tatsuo

    2016-04-01

    Although many studies of the Golgi apparatus structure have been performed by light and electron microscopy, the full shape of the Golgi apparatus remained unclear due to the technical limitations of the previously applied microscopy techniques. In this study, we used serial section scanning electron microscopy (SEM) for the morphological study of the Golgi apparatus. This method is useful for three-dimensional (3D) reconstruction of cellular structures without requiring specialized instruments, unlike focused ion beam SEM (FIB-SEM) and serial block face SEM (SBF-SEM). Using the serial section SEM method developed by our laboratory, we investigate the 3D shape of the osmium-impregnated Golgi apparatus in rat epididymal cells, pancreatic acinar cells and gonadotropes. The combination of serial section SEM and a 3D reconstruction technique enabled us to elucidate the entire shape of the Golgi apparatus in these cells. The full shape of the Golgi apparatus in epididymal cells formed a basket-like structure with oval-shaped cisterns, while the Golgi apparatus in an acinar cell from the pancreas was composed of elongated ribbon-like structures that were connected to each other, making a coarse network. The overall image of the Golgi apparatus cisterns from a gonadotrope looked like a spherical cage. This study has clearly shown that entire 3D shape of the Golgi apparatus varies depending on the cell type and that the Golgi cisterns network appears as a single mass located in the large region of the cytoplasm.

  15. Layer-by-layer self-assembled osmium polymer-mediated laccase oxygen cathodes for biofuel cells: the role of hydrogen peroxide.

    PubMed

    Scodeller, Pablo; Carballo, Romina; Szamocki, Rafael; Levin, Laura; Forchiassin, Flavia; Calvo, Ernesto J

    2010-08-18

    High potential purified Trametes trogii laccase has been studied as a biocatalyst for oxygen cathodes composed of layer-by-layer self-assembled thin films by sequential immersion of mercaptopropane sulfonate-modified Au electrode surfaces in solutions containing laccase and osmium-complex bound to poly(allylamine), (PAH-Os). The polycation backbone carries the Os redox relay, and the polyanion is the enzyme adsorbed from a solution of a suitable pH so that the protein carries a net negative charge. Enzyme thin films were characterized by quartz crystal microbalance, ellipsometry, cyclic voltammetry, and oxygen reduction electrocatalysis under variable oxygen partial pressures with a rotating disk electrode. New kinetic evidence relevant to biofuel cells is presented on the detection of traces of H(2)O(2), intermediate in the O(2) reduction, with scanning electrochemical microscopy (SECM). Furthermore the inhibitory effect of peroxide on the biocatalytic current resulted in abnormal current dependence on the O(2) partial pressure and peak shape with hysteresis in the polarization curves under stagnant conditions, which is offset upon stirring with the RDE. The new kinetic evidence reported in the present work is very relevant for the operation of biofuel cells under stagnant conditions of O(2) mass transport.

  16. Reversible Redox-Based Optical Sensing of Parts per Million Levels of Nitrosyl Cation in Organic Solvents by Osmium Chromophore-Based Monolayers

    SciTech Connect

    Gupta,T.; Cohen, R.; Evmenenko, G.; Dutta, P.; van der Boom, M.

    2007-01-01

    Exposure of an osmium(II)-based monolayer on glass to organic solvents containing 0.36-116 ppm of NOBF{sub 4} results in one-electron transfer from the covalently immobilized complexes to the inorganic analyte with concurrent optical changes. The NO{sup +} induced oxidation of the monolayer can be detected optically with an off-the-self-UV/vis spectrophotometer (260-800 nm). The redox-based NO{sup +} detection and quantification system can be reset with water within {approx}20 s for at least 40 times. The reaction of the monolayer with a THF solution containing 5 ppm of NOBF{sub 4} follows pseudo first-order kinetics in the monolayer with {Delta}G{sup {double_dagger}}{sub 298K} = 21.5 {+-} 0.7 kcal/mol, {Delta}H{sup {double_dagger}} = 9.5 {+-} 0.3 kcal/mol, and {Delta}S{sup {double_dagger}} = -40.6 {+-} 1.1 eu. The monolayer structure and properties have been resolved by electrochemical measurements and synchrotron X-ray reflectivity measurements in combination with density functional theory calculations (B3LYP/SDD level of theory).

  17. Electrochemical detection of DNA binding by tumor suppressor p53 protein using osmium-labeled oligonucleotide probes and catalytic hydrogen evolution at the mercury electrode.

    PubMed

    Němcová, Kateřina; Sebest, Peter; Havran, Luděk; Orság, Petr; Fojta, Miroslav; Pivoňková, Hana

    2014-09-01

    In this paper, we present an electrochemical DNA-protein interaction assay based on a combination of protein-specific immunoprecipitation at magnetic beads (MBIP) with application of oligonucleotide (ON) probes labeled with an electroactive oxoosmium complex (Os,bipy). We show that double-stranded ONs bearing a dT20 tail labeled with Os,bipy are specifically recognized by the tumor suppressor p53 protein according to the presence or absence of a specific binding site (p53CON) in the double-stranded segment. We demonstrate the applicability of the Os,bipy-labeled probes in titration as well as competition MBIP assays to evaluate p53 relative affinity to various sequence-specific or structurally distinct unlabeled DNA substrates upon modulation of the p53-DNA binding by monoclonal antibodies used for the immunoprecipitation. To detect the p53-bound osmium-labeled probes, we took advantage of a catalytic peak yielded by Os,bipy-modified DNA at the mercury-based electrodes, allowing facile determination of subnanogram quantities of the labeled oligonucleotides. Versatility of the electrochemical MBIP technique and its general applicability in studies of any DNA-binding protein is discussed.

  18. Ultraviolet Spectroscopy of Metal-Poor Stars: New Detections of Phosphorus, Germanium, Arsenic, Selenium, Cadmium, Tellurium, Lutetium, Osmium, Iridium, Platinum, Gold, and More!

    NASA Astrophysics Data System (ADS)

    Roederer, Ian U.

    2015-01-01

    Ultraviolet spectroscopy with HST/STIS provides a 30% increase in the number of elements that can be detected in metal-poor stars. Although nearly every element from hydrogen through bismuth is probably present in most metal-poor stars, not all elements can be detected. The resonance lines of the dominant species of some elements are only found in the UV in late-type stars. The chemical compositions of these stars reflect the history of stellar nucleosynthesis from the first stars to today. Here, I present a summary of recent work that has expanded the chemical inventory in metal-poor stars using UV spectroscopy conducted using HST/STIS. The highlights include new detections of phosphorus, germanium, arsenic, selenium, cadmium, tellurium, lutetium, osmium, iridium, platinum, and gold in metal-poor stars. These detections reveal new insights into stellar nucleosynthesis in the earliest generations of massive stars, provide new constraints on the r-process, and open new channels for chemically-tagging stars that have assembled to form the Milky Way stellar halo.

  19. Long-lifetime and long-wavelength osmium (II) metal complexes containing polypyridine ligands: excellent red fluorescent dyes for biophysics and for sensors

    NASA Astrophysics Data System (ADS)

    Murtaza, Zakir; Lakowicz, Joseph R.

    1999-05-01

    Several luminescent complexes of osmium (II) containing polypyridine ligands have been prepared. The syntheses, photophysical and fluorescence polarization properties of [Os(phen)2(aphen)]2+, [Os(tpy)(mcbpy)(py)]2+, [Os(ttpy)2]2+, [Os(tpy)(triphos)]2+ and [Os(tppz)2]2+ are reported. Where phen is 1,10-phenanthroline, aphen is 5-amino-1,10-phenanthroline, tpy is 2,2':6,2'-terpyridine, mcbpy is 4-methyl-2,2'- bipyridine-4'-carboxylic, py is pyridine, triphos is bis(2-diphenylphosphinoethyl)-phenyl phosphine, ttpy is 4- tolyl,2,2':6,2'-terpyridine, and tppz is 2,3,5,6- tetrakis(2-pyridyl)pyrazine. The complexes absorb light at above 550 nm, emit above 700 nm, and have emission lifetimes longer than 50 ns in water. The emission of all the complexes is polarized, so they can have applications as red light excitable dyes for biophysical studies of macromolecules and for polarization immunoassays. The complexes can also be used for lifetime-based oxygen sensing using low-cost phase fluorometry and a LED light source.

  20. Intraepidermal free nerve fiber endings in the hairless skin of the rat as revealed by the zinc iodide-osmium tetroxide technique.

    PubMed

    Müller, T

    2000-04-01

    The nerve fiber distribution in the epidermis of the hairless rat skin was studied light microscopically by means of zinc iodide-osmium tetroxide staining. Two different morphological types of free nerve fiber endings could be detected: clusters of relatively thick nerve fibers stretched up through the spinous layer up to the granular layer sending off terminal branches. In addition, many solitary thin varicose nerve fibers were seen within the epidermis. The observed discrepancies in nerve fiber diameters appeared to be larger than those reported for human intraepidermal nerve fibers in recent immunohistochemical studies. Moreover, dendritic cells, most probably representing Langerhans cells, could be selectively stained. These cells appeared to be in a close location to thin varicose nerve fibers. Both types of demonstrated free nerve endings have to be functionally connected with different sensoric functions. Possibly, a subpopulation of the thin nerve fibers might possess primarily a nociceptive task, whereas the thick ones have most probably to be regarded as mechanoreceptive. The nerve fibers innervating dendritic cells appear to be identical to the peptidergic ones which may regulate the antigen-presenting capacity of these cells. Due to its selectivity for intraepidermal nerve fibers, the used method might supplement immunohistochemical procedures in a helpful manner.