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Sample records for cadmium isotopes probing

  1. Laser spectroscopy of cadmium isotopes: probing the nuclear structure between the neutron 50 and 82 shell closures

    CERN Multimedia

    Blaum, K; Stroke, H H; Krieger, A R

    We propose to study the isotopic chain of cadmium with high-resolution laser spectroscopy for the first time. Our goal is to determine nuclear spins, moments and root-mean-square charge radii of ground and isomeric states between the neutron 50 and 82 shell closures, contributing decisively to a better understanding of the nuclear structure in the vicinity of the doubly-magic $^{100}$Sn and $^{132}$Sn. On the neutron-rich side this is expected to shed light on a shell-quenching hypothesis and consequently on the duration of the r-process along the waiting-point nuclei below $^{130}$Cd. On the neutron-deficient side it may elucidate the role of the cadmium isotopes in the rp-process for rapidly accreting neutron stars.

  2. Intracellular Cadmium Isotope Fractionation

    Science.gov (United States)

    Horner, T. J.; Lee, R. B.; Henderson, G. M.; Rickaby, R. E.

    2011-12-01

    Recent stable isotope studies into the biological utilization of transition metals (e.g. Cu, Fe, Zn, Cd) suggest several stepwise cellular processes can fractionate isotopes in both culture and nature. However, the determination of fractionation factors is often unsatisfactory, as significant variability can exist - even between different organisms with the same cellular functions. Thus, it has not been possible to adequately understand the source and mechanisms of metal isotopic fractionation. In order to address this problem, we investigated the biological fractionation of Cd isotopes within genetically-modified bacteria (E. coli). There is currently only one known biological use or requirement of Cd, a Cd/Zn carbonic anhydrase (CdCA, from the marine diatom T. weissfloggii), which we introduce into the E. coli genome. We have also developed a cleaning procedure that allows for the treating of bacteria so as to study the isotopic composition of different cellular components. We find that whole cells always exhibit a preference for uptake of the lighter isotopes of Cd. Notably, whole cells appear to have a similar Cd isotopic composition regardless of the expression of CdCA within the E. coli. However, isotopic fractionation can occur within the genetically modified E. coli during Cd use, such that Cd bound in CdCA can display a distinct isotopic composition compared to the cell as a whole. Thus, the externally observed fractionation is independent of the internal uses of Cd, with the largest Cd isotope fractionation occurring during cross-membrane transport. A general implication of these experiments is that trace metal isotopic fractionation most likely reflects metal transport into biological cells (either actively or passively), rather than relating to expression of specific physiological function and genetic expression of different metalloenzymes.

  3. Quantitative microbial ecology through stable isotope probing.

    Science.gov (United States)

    Hungate, Bruce A; Mau, Rebecca L; Schwartz, Egbert; Caporaso, J Gregory; Dijkstra, Paul; van Gestel, Natasja; Koch, Benjamin J; Liu, Cindy M; McHugh, Theresa A; Marks, Jane C; Morrissey, Ember M; Price, Lance B

    2015-11-01

    Bacteria grow and transform elements at different rates, and as yet, quantifying this variation in the environment is difficult. Determining isotope enrichment with fine taxonomic resolution after exposure to isotope tracers could help, but there are few suitable techniques. We propose a modification to stable isotope probing (SIP) that enables the isotopic composition of DNA from individual bacterial taxa after exposure to isotope tracers to be determined. In our modification, after isopycnic centrifugation, DNA is collected in multiple density fractions, and each fraction is sequenced separately. Taxon-specific density curves are produced for labeled and nonlabeled treatments, from which the shift in density for each individual taxon in response to isotope labeling is calculated. Expressing each taxon's density shift relative to that taxon's density measured without isotope enrichment accounts for the influence of nucleic acid composition on density and isolates the influence of isotope tracer assimilation. The shift in density translates quantitatively to isotopic enrichment. Because this revision to SIP allows quantitative measurements of isotope enrichment, we propose to call it quantitative stable isotope probing (qSIP). We demonstrated qSIP using soil incubations, in which soil bacteria exhibited strong taxonomic variations in (18)O and (13)C composition after exposure to [(18)O]water or [(13)C]glucose. The addition of glucose increased the assimilation of (18)O into DNA from [(18)O]water. However, the increase in (18)O assimilation was greater than expected based on utilization of glucose-derived carbon alone, because the addition of glucose indirectly stimulated bacteria to utilize other substrates for growth. This example illustrates the benefit of a quantitative approach to stable isotope probing.

  4. Cadmium Isotope Fractionation in Seawater - A Signature of Nutrient Utilization

    Science.gov (United States)

    Wichtlhuber, S.; Rehkaemper, M.; Halliday, A. N.

    2005-12-01

    Cadmium displays a nutrient-like distribution akin to phosphorous in the oceans. This has been attributed to the assimilation of Cd by phytoplankton in surface waters and re-mineralization at depth. If biological uptake is associated with kinetic isotopic fractionation, as recently suggested by Lacan et al. (2005), then the Cd-depleted surface waters of the oceans (with Cd contents of Lacan et al., 2005). In this study, we have extended the search for Cd isotope variations in the oceans with analyses of two depth profiles and various additional seawater samples from the North Pacific, the Arctic, and the Southern Ocean. The Cd isotope measurements utilized a double spike technique in conjunction with multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS), to achieve a precision and accuracy of about ± 0.8 to 1.5 ɛ114/110Cd. This precision is about a factor of 3 to 4 better than that of previous studies, which did not utilize a double spike. The data collected for the samples display a clear co-variation of Cd isotope compositions with Cd concentrations. The most Cd-rich water samples (with ~1 nmol/kg Cd) display the "lightest" Cd isotope compositions with ɛ114/110Cd ~ +3, akin to results previously obtained for crustal and mantle rocks (Wombacher et. al, 2003). In contrast, samples from the upper water column of the North Pacific (with Lacan et al. (2005), because inorganic geological processes (other than evaporation/condensation) do not appear to generate isotope effects as large as those observed in the present study (Wombacher et. al, 2003). These preliminary results suggest that Cd isotopes have the potential to become a useful proxy of nutrient utilization, which could supplement the Cd/Ca and δ13C records of previous studies, if suitable sedimentary archives can be identified that preserve the Cd isotope signatures of past seawater. References: Lacan F., Francois R., Ji Y. and Sherrell R., 2005. Does oceanic productivity production

  5. Fractionation of Stable Cadmium Isotopes in the Cadmium Tolerant Ricinus communis and Hyperaccumulator Solanum nigrum

    Science.gov (United States)

    Wei, Rongfei; Guo, Qingjun; Wen, Hanjie; Liu, Congqiang; Yang, Junxing; Peters, Marc; Hu, Jian; Zhu, Guangxu; Zhang, Hanzhi; Tian, Liyan; Han, Xiaokun; Ma, Jie; Zhu, Chuanwei; Wan, Yingxin

    2016-04-01

    Cadmium (Cd) isotopes provide new insights into Cd uptake, transport and storage mechanisms in plants. Therefore, the present study adopted the Cd-tolerant Ricinus communis and Cd-hyperaccumulator Solanum nigrum, which were cultured under controlled conditions in a nutrient solution with variable Cd supply, to test the isotopic fractionation of Cd during plant uptake. The Cd isotope compositions of nutrient solutions and organs of the plants were measured by multiple collector inductively coupled plasma mass spectrometry (MC-ICPMS). The mass balance of Cd isotope yields isotope fractionations between plant and Cd source (δ114/110Cdorgans-solution) of ‑0.70‰ to ‑0.22‰ in Ricinus communis and ‑0.51‰ to ‑0.33‰ in Solanum nigrum. Moreover, Cd isotope fractionation during Cd transport from stem to leaf differs between the Cd-tolerant and -hyperaccumulator species. Based on these results, the processes (diffusion, adsorption, uptake or complexation), which may induce Cd isotope fractionation in plants, have been discussed. Overall, the present study indicates potential applications of Cd isotopes for investigating plant physiology.

  6. Fractionation of Stable Cadmium Isotopes in the Cadmium Tolerant Ricinus communis and Hyperaccumulator Solanum nigrum

    Science.gov (United States)

    Wei, Rongfei; Guo, Qingjun; Wen, Hanjie; Liu, Congqiang; Yang, Junxing; Peters, Marc; Hu, Jian; Zhu, Guangxu; Zhang, Hanzhi; Tian, Liyan; Han, Xiaokun; Ma, Jie; Zhu, Chuanwei; Wan, Yingxin

    2016-01-01

    Cadmium (Cd) isotopes provide new insights into Cd uptake, transport and storage mechanisms in plants. Therefore, the present study adopted the Cd-tolerant Ricinus communis and Cd-hyperaccumulator Solanum nigrum, which were cultured under controlled conditions in a nutrient solution with variable Cd supply, to test the isotopic fractionation of Cd during plant uptake. The Cd isotope compositions of nutrient solutions and organs of the plants were measured by multiple collector inductively coupled plasma mass spectrometry (MC-ICPMS). The mass balance of Cd isotope yields isotope fractionations between plant and Cd source (δ114/110Cdorgans-solution) of −0.70‰ to −0.22‰ in Ricinus communis and −0.51‰ to −0.33‰ in Solanum nigrum. Moreover, Cd isotope fractionation during Cd transport from stem to leaf differs between the Cd-tolerant and -hyperaccumulator species. Based on these results, the processes (diffusion, adsorption, uptake or complexation), which may induce Cd isotope fractionation in plants, have been discussed. Overall, the present study indicates potential applications of Cd isotopes for investigating plant physiology. PMID:27076359

  7. Cadmium isotope fractionation during adsorption to Mn-oxyhydroxide

    Science.gov (United States)

    Wasylenki, L. E.; Swihart, J. W.

    2013-12-01

    The heavy metal cadmium is of interest both as a toxic contaminant in groundwater and as a critical nutrient for some marine diatoms [1], yet little is known about the biogeochemistry of this element. Horner et al. [2] suggested that Cd stable isotopes could potentially enable reconstruction of biological use of Cd in the marine realm: since cultured diatoms fractionate Cd isotopes [3], and ferromanganese crusts appear to incorporate a faithful record of deepwater Cd isotopes [2], depth profiles in such crusts may yield information about the extent of Cd assimilation of isotopically light Cd by diatoms over time. Although no work has yet been published regarding the use of stable isotopes to track reactive transport of Cd in contaminated aquifers, others have recently demonstrated the potential of isotopes to track reactions affecting the mobility of other toxic metals (e.g., [4]). With both of these potential applications in mind, we conducted two sets of experiments, at low and high ionic strength, in which Cd partially adsorbed to potassium birnessite. Our goals are to quantify the fractionations and to constrain the mechanisms governing Cd isotope behavior during adsorption to an environmentally abundant scavenger of Cd. Suspensions of synthetic birnessite were doped with various amounts of dissolved Cd2+ at pH ~8.3. Following reaction, the dissolved and adsorbed pools of Cd were separated by filtration, purified by anion exchange chromatography, and analyzed by multicollector ICP-MS using a double-spike routine. In all cases, lighter isotopes preferentially adsorbed to the birnessite particles. At low ionic strength (ILacan et al. (2006) Geochim. Cosmochim. Acta. 70, 5104. [4] Berna et al. (2010) Env. Sci. & Tech. 44, 1043.

  8. Probing New Physics with Isotope Shift Spectroscopy

    CERN Document Server

    Delaunay, Cédric

    2016-01-01

    We investigate the potential to probe physics beyond the Standard Model with isotope shift measurements of optical atomic clock transitions. We first derive the reach for generic new physics above the GeV scale at the effective field theory level, as well as estimate the limits on possible new spin-independent forces mediated by sub-GeV states coupled to electrons and neutrons. We also study the weak force and show that isotope shifts could provide strong constraints on the $Z^0$ couplings to valence quarks, which complement precision observables at LEP and atomic parity violation experiments. Finally, motivated by recent experimental hints of a new 750 GeV resonance in diphotons, we also consider the potential to probe its parity-preserving couplings to electrons, quarks and gluons with this method. In particular, combining the diphoton signal with indirect constraints from $g_e-2$ and isotope shifts in Ytterbium allows to probe the resonance coupling to electrons with unprecedented precision.

  9. Cadmium isotope fractionation of materials derived from various industrial processes.

    Science.gov (United States)

    Martinková, Eva; Chrastný, Vladislav; Francová, Michaela; Šípková, Adéla; Čuřík, Jan; Myška, Oldřich; Mižič, Lukáš

    2016-01-25

    Our study represents ϵ(114/110) Cd NIST3108 values of materials resulting from anthropogenic activities such as coal burning, smelting, refining, metal coating, and the glass industry. Additionally, primary sources (ore samples, pigment, coal) processed in the industrial premises were studied. Two sphalerites, galena, coal and pigment samples exhibited ϵ(114/110) CdNIST3108 values of 1.0±0.2, 0.2±0.2, 1.3±0.1, -2.3±0.2 and -0.1±0.3, respectively. In general, all studied industrial processes were accompanied by Cd isotope fractionation. Most of the industrial materials studied were clearly distinguishable from the samples used as a primary source based on ϵ(114/110) Cd NIST3108 values. The heaviest ϵ(114/110) CdNIST3108 value of 58.6±0.9 was found for slag resulting from coal combustion, and the lightest ϵ(114/110) CdNIST3108 value of -23±2.5 was observed for waste material after Pb refinement. It is evident that ϵ(114/110) Cd NIST3108 values depend on technological processes, and in case of incomplete Cd transfer from source to final waste material, every industrial activity creates differences in Cd isotope composition. Our results show that Cd isotope analysis is a promising tool to track the origins of industrial waste products.

  10. A portable cadmium telluride multidetector probe for cardiac function monitoring

    CERN Document Server

    Arntz, Y; Dumitresco, B; Eclancher, B; Prat, V

    1999-01-01

    A new nuclear stethoscope based on a matrix of small CdTe semiconductor detectors has been developed for studying the cardiac performance by gamma ventriculography at the equilibrium, in rest and stress conditions, in the early and recovery phases of the coronary disease and to follow the long-term therapy. The light-weight probe consists of an array of 64 detectors 5x5x2 mm grouped in 16 independent units in a lead shielded aluminum box including 16 preamplifiers. The probe is connected to an electronic box containing DC power supply, 16 channel amplifiers, discriminators and counters, two analog-triggering ECG channels, and interface to a PC. The left ventricle activity is, preferentially, detected by using a low-resolution matching convergent collimator. A physical evaluation of the probe has been performed, both with static tests and dynamically with a hydraulic home-built model of beating heart ventricle paced by a rhythm simulator. The sum of the 16 detectors activity provided a radiocardiogram (RCG) wh...

  11. Using phylogenetic probes for quantification of stable isotope labeling and microbial community analysis

    Energy Technology Data Exchange (ETDEWEB)

    Brodie, Eoin L; DeSantis, Todd Z; Karaoz, Ulas; Andersen, Gary L

    2014-12-09

    Herein is described methods for a high-sensitivity means to measure the incorporation of stable isotope labeled substrates into RNA following stable isotope probing experiments (SIP). RNA is hybridized to a set of probes such as phylogenetic microarrays and isotope incorporation is quantified such as by secondary ion mass spectrometer imaging (NanoSIMS).

  12. Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Stoeppler, M. (Kernforschungsanlage Juelich G.m.b.H. (Germany, F.R.). Inst. fuer Angewandte Physikalische Chemie); Piscator, M. (Karolinska Inst., Stockholm (Sweden). Dept. of Environmental Hygiene) (eds.)

    1988-01-01

    The proceedings contain the 18 papers presented at the workshop. They are dealing with the following themes: Toxicity, carcinogenesis and metabolism of cadmium, epidemiology; environmental occurrence; quantitative analysis and quality assessment. (MG) With 57 figs., 79 tabs.

  13. Cadmium-free quantum dots as time-gated bioimaging probes in highly-autofluorescent human breast cancer cells.

    Science.gov (United States)

    Mandal, Gopa; Darragh, Molly; Wang, Y Andrew; Heyes, Colin D

    2013-01-21

    We report cadmium-free, biocompatible (Zn)CuInS(2) quantum dots with long fluorescence lifetimes as superior bioimaging probes using time-gated detection to suppress cell autofluorescence and improve the signal : background ratio by an order of magnitude. These results will be important for developing non-toxic fluorescence imaging probes for ultrasensitive biomedical diagnostics.

  14. The isotopic composition of dissolved cadmium in the water column of the West Philippine Sea

    Directory of Open Access Journals (Sweden)

    Shun-Chung eYang

    2014-11-01

    Full Text Available The dissolved concentration and isotopic compositions of cadmium (Cd in the seawater of the West Philippine Sea were determined. In general, Cd isotopic composition in the water column decreased with depth, with ε114/110Cd (ε114/110Cd = [(114Cd/110Cdsample / (114Cd/110CdNIST 3108 - 1]×10000 ranging from +7.2 to +10.1 in the top 60 m, from +4.8 to +5.1 between 100 and 150 m, peaking at +8.2 at 200 m, decreasing from +4.5 to +3.3 from 400 to 1000 m, and remaining constant at +3.0 from 1000 m and deeper. Different to a Rayleigh fractionation model, the isotopic composition and log scale concentrations of Cd do not exhibit a linear relationship. However, from the deep water to thermocline, the variations in Cd concentration and ε114/110Cd are relevant to the variations of temperature and salinity, indicating that water mixing is the dominant processes determining the concentration and isotopic composition in the interval. At 200 m where North Pacific Tropic Water dominates the water mass, the elevated ε114/110Cd could be linked to the composition in the upper portions of the water mass. In the top 150 m, the ε114/110Cd varies similarly to the phytoplankton community structures, implying that Cd uptake by various phytoplankton species may be associated with the isotopic variation. However, the effects of atmospheric inputs to the ε114/110Cd in the surface water cannot be excluded. A box model calculation is used to constrain the contributions of various processes to the Cd isotopes of surface water, and the results indicate that the Cd concentration and isotopic composition in most of the water body of the region are controlled by physical mixing, while the effects of biological fractionation and atmospheric inputs are limited in the euphotic zone.

  15. Cadmium-isotopic evidence for increasing primary productivity during the Late Permian anoxic event

    Science.gov (United States)

    Georgiev, Svetoslav V.; Horner, Tristan J.; Stein, Holly J.; Hannah, Judith L.; Bingen, Bernard; Rehkämper, Mark

    2015-01-01

    Earth's most extreme extinction event near the end of the Late Permian decimated more than 90% of all extant marine species. Widespread and intensive oceanic anoxia almost certainly contributed to the catastrophe, though the driving mechanisms that sustained such conditions are still debated. Of particular interest is whether water column anoxia was a consequence of a 'stagnant ocean', or if it was controlled by increases in nutrient supply, primary productivity, and subsequent heterotrophic respiration. Testing these competing hypotheses requires deconvolving sedimentary/bottom water redox conditions from changes in surface water productivity in marine sediments. We address this issue by studying marine shales from East Greenland and the mid-Norwegian shelf and combining sedimentary redox proxies with cadmium-isotopic analyses. Sedimentary nitrogen-isotopic data, pyrite framboid analyses, and organic and inorganic shale geochemistry reveal sulfidic conditions with vigorous upwelling, and increasingly anoxic conditions with a strengthening upwelling in the Greenland and Norwegian sections, respectively. Detailed analysis of sedimentary metal budgets illustrates that Cd is primarily associated with organic carbon and records primary geochemical signatures, thus enabling reconstruction of surface water nutrient utilization. Cadmium-isotopic analyses of the authigenic shale fraction released by inverse aqua regia digestion yield an average δ114Cd110 of + 0.15 ± 0.01 ‰ (2 SE, n = 12; rel. NIST SRM 3108), indicative of incomplete surface water nutrient utilization up-section. The constant degree of nutrient utilization combined with strong upwelling requires increasing primary productivity - and not oceanic stagnation - to balance the larger nutrient fluxes to both study sites during the development of the Late Permian water column anoxia. Overall, our data illustrate that if bottom water redox and upwelling can be adequately constrained, Cd-isotopic analyses of

  16. Concurrent reduction and distillation: an improved technique for the recovery and chemical refinement of the isotopes of cadmium and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Caudill, H.H.; McBride, L.E.; McDaniel, E.W.

    1982-01-01

    The Electromagnetic Isotope Separations Program of the Oak Ridge National Laboratory has been involved in the separation, chemical recovery, and refinement of the stable isotopes of cadmium and zinc since 1946. Traditionally, the chemical refinement procedures for these elements consisted of ion exchange separations using anion exchange resins followed by pH-controlled hydrogen sulfide precipitations. The procedures were quite time-consuming and made it difficult to remove trace quantities of sulfur which interferes in subsequent attempts to prepare rolled metal foils. As demands for /sup 113/Cd and /sup 68/Zn (a precursor for the production of the radiopharmaceutical /sup 67/Ga) increased, it became evident that a quicker, more efficient refinement procedure was needed. Details of an improved method, which employs concurrent hydrogen reduction and distillation in the recovery and refinement of isotopically enriched zinc, are described. Modifications of the procedure suitable for the refinement of cadmium isotopes are also described. 3 figures, 1 table.

  17. Tracing industrial heavy metal inputs to topsoils using using cadmium isotopes

    Science.gov (United States)

    Huang, Y.; Ma, L.; Ni, S.; Lu, H.; Liu, Z.; Zhang, C.; Guo, J.; Wang, N.

    2015-12-01

    Anthropogenic activities have dominated heavy metal (such as Cd, Pb, and Zn) cycling in many environments. The extent and fate of these metal depositions in topsoils, however, have not been adequately evaluated. Here, we utilize an innovative Cadmium (Cd) isotope tool to trace the sources of metal pollutants in topsoils collected from surrounding a Vanadium Titanium Magnetite smelting plant in Sichuan, China. Topsoil samples and possible pollution end-members such as fly ashes, bottom ashes, ore materials, and coal were also collected from the region surrounding the smelting plant and were analyzed for Cd isotope ratios (d114Cd relative to Cd NIST 3108). Large Cd isotope fractionation (up to 3 ‰) was observed in these industrial end-members: fly ashes possessed higher δ114Cd values ranging from +0.03 to +0.19‰; bottom fly ashes have lower δ114Cd values ranging from -0.35 to -2.46‰; and unprocessed ore and coal samples has δ114Cd value of -0.40‰. This fractionation can be attributed to the smelting processes during which bottom ashes acquired lighter Cd isotope signatures while fly ashes were mainly characterized by heavy isotope ratios, in comparison to the unprocessed ore and coal samples. Indeed, δ114Cd values of topsoils in the smelting area range from 0.29 to -0.56‰, and more than half of the soils analyzed have distinct δ114Cd values > 0‰. Cd isotopes and concentrations measured in topsoils suggested that processed materials (fly and bottom ashes from ore and coal actually used by the smelting plant) were the major source of Cd in soils. In a δ114Cd vs 1/Cd mixing diagram, the soils represent a mixture of three identified end members (fly ash, bottom ash and deep unaffected soil) with distinct Cd isotopic compositions and concentrations. Deep soils have the same δ114Cd values range as the unprocessed ore and coal, which indicated the Cd isotope fractionation did occur during evaporation and condensation processes inside the smelting plant

  18. Bioavailability of xenobiotics in unsaturated soils – implications for nucleic acid based stable isotope probing

    Science.gov (United States)

    The use of stable isotopes to label phylogenetically informative biomolecules (phospholipid fatty acids, DNA, or RNA), typically referred to as stable isotope probing (SIP) has the potential of providing definitive evidence that a detected population is active in a specific process, if that process ...

  19. Synthesis of cadmium, lead and copper alginate nanobeads as immunosensing probes for the detection of AFP, CEA and PSA.

    Science.gov (United States)

    Wang, Zifeng; Liu, Na; Feng, Feng; Ma, Zhanfang

    2015-08-15

    A double-water-in-oil-emulsion procedure was designed to synthesize cadmium, lead and copper alginate nanobeads less than 200n m diameter under mild conditions. The cadmium, lead and copper alginate nanobeads can be activated to immobilize biomacromolecules and can directly produce distinctive electrochemical signals. Using the novel alginate nanobeads labeled with antibodies as electrochemical probes, a sandwich-type immunosensor was constructed using AFP, CEA and PSA as model analytes. This proposed immunosensor shows wide linear range with detection limits of 0.01, 0.0086 and 0.0075 ng mL(-1) for AFP, CEA and PSA, respectively. Analysis of clinical serum samples using this immunosensor was well consistent with the data determined by the enzyme-linked immunosorbent assay (ELISA). It suggested that the alginate nanobeads electrochemical probes could be generally extended to other multiple analytes detection.

  20. Isotopic zirconium as a probe of AGB nucleosynthesis theory

    Science.gov (United States)

    Malaney, R. A.

    Nuclear reaction network calculations of the zirconium relative isotope abundances in AGB stars are presented. It is shown how these isotopic abundances depend on the AGB stellar mass and on the uncertain neutron absorption cross section for Zr-96. With regard to observations of the zirconium isotopes in S stars, it is shown how the many neutron exposure mechanisms associated with AGB thermal pulses cannot be operating in these stars. A less predictable scheme in which only a few neutron exposures take place appears to be more consistent with the reported S star observations.

  1. Probing isotope effects in chemical reactions using single ions

    CERN Document Server

    Staanum, Peter F; Wester, Roland; Drewsen, Michael

    2008-01-01

    Isotope effects in reactions between Mg+ in the 3p 2P3/2 excited state and molecular hydrogen at thermal energies are studied through single reaction events. From only ~250 reactions with HD, the branching ratio between formation of MgD+ and MgH+ is found to be larger than 5. From additional 65 reactions with H2 and D2 we find that the overall decay probability of the intermediate MgH2+, MgHD+ or MgD2+ complexes is the same. Our study shows that few single ion reactions can provide quantitative information on ion-neutral reactions. Hence, the method is well-suited for reaction studies involving rare species, e.g., rare isotopes or short-lived unstable elements.

  2. Nanometer-scale isotope analysis of bulk diamond by atom probe tomography

    NARCIS (Netherlands)

    Schirhagl, R.; Raatz, N.; Meijer, J.; Markham, M.; Gerstl, S. S. A.; Degen, C. L.

    2015-01-01

    Atom-probe tomography (APT) combines field emission of atoms with mass spectrometry to reconstruct three-dimensional tomograms of materials with atomic resolution and isotope specificity. Despite significant recent progress in APT technology, application to wide-bandgap materials with strong covalen

  3. Identification of triclosan-degrading bacteria using stable isotope probing, fluorescence in situ hybridization and microautoradiography

    DEFF Research Database (Denmark)

    Lolas, Ihab Bishara Lolas; Chen, Xijuan; Bester, Kai

    2012-01-01

    -based stable isotope probing (DNA-SIP) combined with microautoradiography-fluorescence in situ hybridization (MAR-FISH) was applied to identify active triclosan degraders in an enrichment culture inoculated with activated sludge. Clone library sequences of 16S rRNA genes derived from the heavy DNA fractions...

  4. EPR of Cu(II) in sarcosine cadmium chloride: probe into dopant site - symmetry and copper-sarcosine interaction

    CERN Document Server

    Pathinettam-Padiyan, D; Murugesan, R

    2000-01-01

    The electron paramagnetic resonance spectra of Cu(II) doped sarcosine cadmium chloride single crystals have been investigated at room temperature. Experimental results reveal that the Cu(II) ion enters the lattice interstitially. The observed superhyperfine lines indicate the superposition of two sets of quintet structure with interaction of nitrogen atoms and the two isotopes of copper. The spin Hamiltonian parameters are evaluated by Schonland method and the electric field symmetry around the copper ion is rhombic. An admixture of d sub z sup 2 orbital with the d sub x sub sup 2 sub - sub y sub sup 2 ground state is observed. Evaluation of MO coefficients reveals that the in-plane interaction between copper and nitrogen is strong in this lattice.

  5. Hydrogen isotope composition of mantle-derived mica megacryst from ion micro probe analysis

    Institute of Scientific and Technical Information of China (English)

    夏群科; 陈道公; 支霞臣

    1999-01-01

    The hydrogen isotope composition of a mantle-derived mica megacryst from Cenozoic basanite from NUshan, Anhui Province has been determined by ion micro probe. The results demonstrate that δD and water content of the megacryst were heterogeneous on the micro scale, which resulted from reaction with meteoric water after being brought to the surface. The primary δD of mica megacrysts was about-23‰, suggesting the recycled crustal materials in its source. By combining these values with those of other researchers, it is believed that the hydrogen isotope composition of the mantle is heterogeneous at least on the large scale.

  6. Precision mass measurements for studies of nucleosynthesis via the rapid neutron-capture process. Penning-trap mass measurements of neutron-rich cadmium and caesium isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Atanasov, Dinko

    2016-07-06

    Although the theory for the rapid neutron-capture process (r-process) was developed more than 55 years ago, the astrophysical site is still under a debate. Theoretical studies predict that the r-process path proceeds through very neutron-rich nuclei with very asymmetric proton-to-neutron ratios. Knowledge about the properties of neutron-rich isotopes found in similar regions of the nuclear chart and furthermore suitable for r-process studies is still little or even not existing. The basic nuclear properties such as binding energies, half-lives, neutron-induced or neutron-capture reaction cross-sections, play an important role in theoretical simulations and can vary or even drastically alternate results of these studies. Therefore, a considerable effort was put forward to access neutron-rich isotopes at radioactive ion-beam facilities like ISOLDE at CERN. The goal of this PhD thesis is to describe the experimental work done for the precision mass measurements of neutron-rich cadmium ({sup 129-131}Cd) and caesium ({sup 132,146-148}Cs) isotopes. Measurements were done at the on-line radioactive ion-beam facility ISOLDE by using the four-trap mass spectrometer ISOLTRAP. The cadmium isotopes are key nuclides for the synthesis of stable isotopes around the mass peak A = 130 in the Solar System abundance.

  7. Zn/Cd ratios and cadmium isotope evidence for the classification of lead-zinc deposits.

    Science.gov (United States)

    Wen, Hanjie; Zhu, Chuanwei; Zhang, Yuxu; Cloquet, Christophe; Fan, Haifeng; Fu, Shaohong

    2016-04-28

    Lead-zinc deposits are often difficult to classify because clear criteria are lacking. In recent years, new tools, such as Cd and Zn isotopes, have been used to better understand the ore-formation processes and to classify Pb-Zn deposits. Herein, we investigate Cd concentrations, Cd isotope systematics and Zn/Cd ratios in sphalerite from nine Pb-Zn deposits divided into high-temperature systems (e.g., porphyry), low-temperature systems (e.g., Mississippi Valley type [MVT]) and exhalative systems (e.g., sedimentary exhalative [SEDEX]). Our results showed little evidence of fractionation in the high-temperature systems. In the low-temperature systems, Cd concentrations were the highest, but were also highly variable, a result consistent with the higher fractionation of Cd at low temperatures. The δ(114/110)Cd values in low-temperature systems were enriched in heavier isotopes (mean of 0.32 ± 0.31‰). Exhalative systems had the lowest Cd concentrations, with a mean δ(114/110)Cd value of 0.12 ± 0.50‰. We thus conclude that different ore-formation systems result in different characteristic Cd concentrations and fraction levels and that low-temperature processes lead to the most significant fractionation of Cd. Therefore, Cd distribution and isotopic studies can support better understanding of the geochemistry of ore-formation processes and the classification of Pb-Zn deposits.

  8. Quinone-based stable isotope probing for assessment of 13C substrate-utilizing bacteria

    Science.gov (United States)

    Kunihiro, Tadao; Katayama, Arata; Demachi, Toyoko; Veuger, Bart; Boschker, Henricus T. S.; van Oevelen, Dick

    2015-04-01

    In this study, we attempted to establish quinone-stable-isotope probing (SIP) technique to link substrate-utilizing bacterial group to chemotaxonomic group in bacterial community. To identify metabolically active bacterial group in various environments, SIP techniques combined with biomarkers have been widely utilized as an attractive method for environmental study. Quantitative approaches of the SIP technique have unique advantage to assess substrate-incorporation into bacteria. As a most major quantitative approach, SIP technique based on phospholipid-derived fatty acids (PLFA) have been applied to simultaneously assess substrate-incorporation rate into bacteria and microbial community structure. This approach is powerful to estimate the incorporation rate because of the high sensitivity due to the detection by a gas chromatograph-combustion interface-isotope ratio mass spectrometer (GC-c-IRMS). However, its phylogenetic resolution is limited by specificity of a compound-specific marker. We focused on respiratory quinone as a biomarker. Our previous study found a good correlation between concentrations of bacteria-specific PLFAs and quinones over several orders of magnitude in various marine sediments, and the quinone method has a higher resolution (bacterial phylum level) for resolving differences in bacterial community composition more than that of bacterial PLFA. Therefore, respiratory quinones are potentially good biomarkers for quantitative approaches of the SIP technique. The LC-APCI-MS method as molecular-mass based detection method for quinone was developed and provides useful structural information for identifying quinone molecular species in environmental samples. LC-MS/MS on hybrid triple quadrupole/linear ion trap, which enables to simultaneously identify and quantify compounds in a single analysis, can detect high molecular compounds with their isotope ions. Use of LC-MS/MS allows us to develop quinone-SIP based on molecular mass differences due to

  9. Comparative study between probe focussed sonication and conventional stirring in the evaluation of cadmium and copper in plants

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Sara; Fonseca, Luis P. [Technical University of Lisbon, Centro de Engenharia Quimica e Biologica, Instituto Superior Tecnico, Lisbon (Portugal); Capelo, Jose L. [University of Vigo at Ourense Campus, Analytical and Food Chemistry Department, Science Faculty, Ourense (Spain); Armas, Teresa; Vilhena, Fernanda; Goncalves, Maria L.S.; Mota, A.M. [Technical University of Lisbon, Centro de Quimica Estrutural, Instituto Superior Tecnico, Lisbon (Portugal); Pinto, Ana P. [University of Evora, Herdade Experimental da Mitra, ICAAM-Instituto de Ciencias Agrarias e Ambientais Mediterranicas, Evora (Portugal)

    2010-11-15

    Ultrasound (US)-assisted extraction has been widely used for metal ion extraction in plants due to its unique properties of decreased extraction time, minimal contamination, low reagent consumption and low cost. However, very few papers present a sound comparison between probe-focussed sonication and conventional stirring in the evaluation of metal ion extraction in plants. In this study, ultrasonic-assisted digestion has been evaluated and compared to magnetic stirring for total copper and cadmium determination by atomic absorption spectrometry in biological samples (plants, plankton and mussels). The same experimental conditions of sample amount and particle size, extractant solution and extraction time were applied for both ultrasound and magnetic stirring-assisted extraction methods in order to truly compare their effect on metal ion solubilisation. To gain further insight in this issue, dried and fresh plants were tested. The results obtained indicated that osmotic tension in cell walls, produced when dried and powdered samples were immersed in the extractant solution, had an important contribution to metal ion solubilisation, the enhancement due to US for the same purpose being negligible. (orig.)

  10. Comparative study between probe focussed sonication and conventional stirring in the evaluation of cadmium and copper in plants.

    Science.gov (United States)

    Pereira, Sara; Fonseca, Luís P; Capelo, José L; Armas, Teresa; Vilhena, Fernanda; Pinto, Ana P; Gonçalves, Maria L S; Mota, A M

    2010-11-01

    Ultrasound (US)-assisted extraction has been widely used for metal ion extraction in plants due to its unique properties of decreased extraction time, minimal contamination, low reagent consumption and low cost. However, very few papers present a sound comparison between probe-focussed sonication and conventional stirring in the evaluation of metal ion extraction in plants. In this study, ultrasonic-assisted digestion has been evaluated and compared to magnetic stirring for total copper and cadmium determination by atomic absorption spectrometry in biological samples (plants, plankton and mussels). The same experimental conditions of sample amount and particle size, extractant solution and extraction time were applied for both ultrasound and magnetic stirring-assisted extraction methods in order to truly compare their effect on metal ion solubilisation. To gain further insight in this issue, dried and fresh plants were tested. The results obtained indicated that osmotic tension in cell walls, produced when dried and powdered samples were immersed in the extractant solution, had an important contribution to metal ion solubilisation, the enhancement due to US for the same purpose being negligible.

  11. Cadmium phytoavailability in soils and evaluation of extractant effectiveness using an isotope technique

    Directory of Open Access Journals (Sweden)

    Fernando Guerra

    2014-10-01

    Full Text Available Large areas of land are nowadays contaminated by heavy metals and, it is therefore, important to monitor their levels in soils. Vegetables act as transfer mechanisms of such contaminants from soils to higher levels in the food chain. In this study, we aimed to evaluate the effectiveness of chemical extractants by the L-value method for Cd phytoavailability using the 109Cd radionuclide. In a greenhouse experiment, rocket plants (Eruca sativa L. were cultivated in pots with samples from Typic Hapludox and Typic Quartzipsamment soils. Cadmium concentrations ranging from 0 to 16 mg kg-1 were added to a 200 mL solution containing 148 kBq 109Cd. The available Cd in the soil was extracted by DTPA, Mehlich-1, Mehlich-3, and a mixture of organic acids (acetic, citric, lactic, and oxalic acids. Cd concentrations were determined by atomic absorption spectrophotometry, and 109Cd radionuclide activity was measured by low-level β-counting. The dry matter yield was not influenced by Cd rates, but the Cd content and accumulation in shoots had a positive linear correlation. Generally, Cd was extracted in higher quantities by Mehlich-1 followed by DTPA, Mehlich-3, and organic acids. A linear correlation was found between the chemical extractants and Cd accumulation in shoots for both soils. According to the L Ratio, the extractants based on strong acids and chelating agents presented low efficiency regarding Cd phytoavailability. The organic acids, which presented values close to the L-value, may provide a promising method for evaluating environmental contaminants.

  12. Visualizing Microbial Biogeochemistry: NanoSIMS and Stable Isotope Probing (Invited)

    Science.gov (United States)

    Pett-Ridge, J.; Weber, P. K.

    2009-12-01

    Linking phylogenetic information to function in microbial communities is a key challenge for microbial ecology. Isotope-labeling experiments provide a useful means to investigate the ecophysiology of microbial populations and cells in the environment and allow measurement of nutrient transfers between cell types, symbionts and consortia. The combination of Nano-Secondary Ion Mass Spectrometry (NanoSIMS) analysis, in situ labeling and high resolution microscopy allows isotopic analysis to be linked to phylogeny and morphology and holds great promise for fine-scale studies of microbial systems. In NanoSIMS analysis, samples are sputtered with an energetic primary beam (Cs+, O-) liberating secondary ions that are separated by the mass spectrometer and detected in a suite of electron multipliers. Five isotopic species may be analyzed concurrently with spatial resolution as fine as 50nm. A high sensitivity isotope ratio ‘map’ can then be generated for the analyzed area. NanoSIMS images of 13C, 15N and Mo (a nitrogenase co-factor) localization in diazotrophic cyanobacteria show how cells differentially allocate resources within filaments and allow calculation of nutrient uptake rates on a cell by cell basis. Images of AM fungal hyphae-root and cyanobacteria-rhizobia associations indicate the mobilization and sharing (stealing?) of newly fixed C and N. In a related technique, “El-FISH”, stable isotope labeled biomass is probed with oligonucleotide-elemental labels and then imaged by NanoSIMS. In microbial consortia and cyanobacterial mats, this technique helps link microbial structure and function simultaneously even in systems with unknown and uncultivated microbes. Finally, the combination of re-engineered universal 16S oligonucleotide microarrays with NanoSIMS analyses may allow microbial identity to be linked to functional roles in complex systems such as mats and cellulose degrading hindgut communities. These newly developed methods provide correlated

  13. Probing reversible chemistry in coenzyme B12 -dependent ethanolamine ammonia lyase with kinetic isotope effects.

    Science.gov (United States)

    Jones, Alex R; Rentergent, Julius; Scrutton, Nigel S; Hay, Sam

    2015-06-08

    Coenzyme B12 -dependent enzymes such as ethanolamine ammonia lyase have remarkable catalytic power and some unique properties that enable detailed analysis of the reaction chemistry and associated dynamics. By selectively deuterating the substrate (ethanolamine) and/or the β-carbon of the 5'-deoxyadenosyl moiety of the intrinsic coenzyme B12 , it was possible to experimentally probe both the forward and reverse hydrogen atom transfers between the 5'-deoxyadenosyl radical and substrate during single-turnover stopped-flow measurements. These data are interpreted within the context of a kinetic model where the 5'-deoxyadenosyl radical intermediate may be quasi-stable and rearrangement of the substrate radical is essentially irreversible. Global fitting of these data allows estimation of the intrinsic rate constants associated with CoC homolysis and initial H-abstraction steps. In contrast to previous stopped-flow studies, the apparent kinetic isotope effects are found to be relatively small.

  14. An ultrasensitive method for the determination of melamine using cadmium telluride quantum dots as fluorescence probes

    Energy Technology Data Exchange (ETDEWEB)

    Li, Xiafei; Li, Jin; Kuang, Huiyan; Feng, Lei; Yi, Shoujun; Xia, Xiaodong; Huang, Haowen [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, Hunan University of Science and Technology, Xiangtan 411201 (China); Chen, Yong; Tang, Chunran [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Zeng, Yunlong, E-mail: yunlongzeng1955@126.com [School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201 (China); Key Laboratory of Theoretical Chemistry and Molecular Simulation of Ministry of Education of China, Hunan University of Science and Technology, Xiangtan 411201 (China); State Key Laboratory for Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)

    2013-11-13

    Graphical abstract: Melamine takes place of the TGA on the surface of TGA-CdTe QDs with negative charge to form melamine coated QDs changing the surface charge of the QDs, resulting the fluorescence quenched as the QDs aggregation occurred by electrostatic attraction of the two opposite charged nanocrystals. -- Highlights: •An ultrasensitive and selective method for the determination of melamine was developed at pH 11.0. •The selectivity of the method was improved. •The sensitivity of the method enhanced obviously as the CdTe QDs have higher QYs at pH 11. •The sensitivity and linear range for the analysis are size dependent using QDs PL probes. •Melamine takes the place of TGA resulting fluorescence quenched of QDs. -- Abstract: An ultrasensitive and simple method for the determination of melamine was developed based on the fluorescence quenching of thioglycolic acid (TGA) capped CdTe quantum dots (QDs) at pH 11.0. In strong alkaline aqueous solution, the selectivity of the method has been greatly improved due to most heavy metal ions show no interference as they are in the precipitation form or in their anion form. Furthermore, CdTe quantum dots have higher quantum yields at higher pH. The method has a wider concentration range and lower detection limit. The influence factors on the determination of melamine were investigated and the optimum conditions were determined. Under optimum conditions, the fluorescence intensity change of TGA coated CdTe quantum dots was linearly proportional to melamine over a concentration range from 1.0 × 10{sup −11} to 1.0 × 10{sup −5} mol L{sup −1} with a correlation coefficient of 0.9943 and a detection limit of 5 × 10{sup −12} mol L{sup −1}. The mechanism of fluorescence quenching of the QDs has been proposed based on the infrared spectroscopy information and electrophoresis experiments in presence of melamine under alkaline condition. The proposed method was employed to detect trace melamine in milk powder

  15. Proteomic Stable Isotope Probing Reveals Taxonomically Distinct Patterns in Amino Acid Assimilation by Coastal Marine Bacterioplankton.

    Science.gov (United States)

    Bryson, Samuel; Li, Zhou; Pett-Ridge, Jennifer; Hettich, Robert L; Mayali, Xavier; Pan, Chongle; Mueller, Ryan S

    2016-01-01

    Heterotrophic marine bacterioplankton are a critical component of the carbon cycle, processing nearly a quarter of annual primary production, yet defining how substrate utilization preferences and resource partitioning structure microbial communities remains a challenge. In this study, proteomic stable isotope probing (proteomic SIP) was used to characterize population-specific assimilation of dissolved free amino acids (DFAAs), a major source of dissolved organic carbon for bacterial secondary production in aquatic environments. Microcosms of seawater collected from Newport, Oregon, and Monterey Bay, California, were incubated with 1 µM (13)C-labeled amino acids for 15 and 32 h. The taxonomic compositions of microcosm metaproteomes were highly similar to those of the sampled natural communities, with Rhodobacteriales, SAR11, and Flavobacteriales representing the dominant taxa. Analysis of (13)C incorporation into protein biomass allowed for quantification of the isotopic enrichment of identified proteins and subsequent determination of differential amino acid assimilation patterns between specific bacterioplankton populations. Proteins associated with Rhodobacterales tended to have a significantly high frequency of (13)C-enriched peptides, opposite the trend for Flavobacteriales and SAR11 proteins. Rhodobacterales proteins associated with amino acid transport and metabolism had an increased frequency of (13)C-enriched spectra at time point 2. Alteromonadales proteins also had a significantly high frequency of (13)C-enriched peptides, particularly within ribosomal proteins, demonstrating their rapid growth during incubations. Overall, proteomic SIP facilitated quantitative comparisons of DFAA assimilation by specific taxa, both between sympatric populations and between protein functional groups within discrete populations, allowing an unprecedented examination of population level metabolic responses to resource acquisition in complex microbial communities

  16. Multiple effects of cadmium on the photosynthetic apparatus of Avicennia germinans L. as probed by OJIP chlorophyll fluorescence measurements

    Energy Technology Data Exchange (ETDEWEB)

    Gonzales-Mendoza, D.; Zapata-Perez, O. [Cinvestav Unidad Merida, Yucatan (Mexico). Dept. de Recursos del Mar; Espadas y Gil, F.; Santamaria, J.M. [Unidad de Biotecnologia, CICY, Yucatan (Mexico)

    2007-03-15

    The toxic effects of cadmium on the photosynthetic apparatus of Avicennia germinans were evaluated by means of the chlorophyll fluorescence transient O-J-I-P. The chlorophyll fluorescence transients were recorded in vivo with high time resolution and analyzed according to the OJIP-test that can quantify the performance of photosystem II. Cadmium-treated plants showed a decrease in yield for primary photochemistry, TR{sup 0}/ABS. The performance index of photosystem II (PSII), PI{sub ABS}, decreased due to cadmium treatment. This performance index is the combination of the indexes of three independent parameters: (1) total number of active reaction centers per absorption (RC/ABS), (2) yield of primary photochemistry (TR{sup 0}/ABS), and (3) efficiency with which a trapped exciton can move an electron into the electron transport chain (ET{sup 0}/TR{sup 0}). Additionally, the F{sub 0}/F{sub v} registered the highest sensitivity to the metal, thus indicating that the water-splitting apparatus of the oxidizing side of PSII is the primary site of action of cadmium. In summary, cadmium affects several targets of photosystem II. More specifically the main targets of cadmium, according to the OJIP-test, can be listed as a decrease in the number of active reaction centers and damage to the activity of the water-splitting complex. (orig.)

  17. Probing the metabolic water contribution to intracellular water using oxygen isotope ratios of PO4

    Science.gov (United States)

    Li, Hui; Yu, Chan; Wang, Fei; Chang, Sae Jung; Yao, Jun; Blake, Ruth E.

    2016-05-01

    Knowledge of the relative contributions of different water sources to intracellular fluids and body water is important for many fields of study, ranging from animal physiology to paleoclimate. The intracellular fluid environment of cells is challenging to study due to the difficulties of accessing and sampling the contents of intact cells. Previous studies of multicelled organisms, mostly mammals, have estimated body water composition—including metabolic water produced as a byproduct of metabolism—based on indirect measurements of fluids averaged over the whole organism (e.g., blood) combined with modeling calculations. In microbial cells and aquatic organisms, metabolic water is not generally considered to be a significant component of intracellular water, due to the assumed unimpeded diffusion of water across cell membranes. Here we show that the 18O/16O ratio of PO4 in intracellular biomolecules (e.g., DNA) directly reflects the O isotopic composition of intracellular water and thus may serve as a probe allowing direct sampling of the intracellular environment. We present two independent lines of evidence showing a significant contribution of metabolic water to the intracellular water of three environmentally diverse strains of bacteria. Our results indicate that ˜30-40% of O in PO4 comprising DNA/biomass in early stationary phase cells is derived from metabolic water, which bolsters previous results and also further suggests a constant metabolic water value for cells grown under similar conditions. These results suggest that previous studies assuming identical isotopic compositions for intracellular/extracellular water may need to be reconsidered.

  18. Identification of the autotrophic denitrifying community in nitrate removal reactors by DNA-stable isotope probing.

    Science.gov (United States)

    Xing, Wei; Li, Jinlong; Cong, Yuan; Gao, Wei; Jia, Zhongjun; Li, Desheng

    2017-04-01

    Autotrophic denitrification has attracted increasing attention for wastewater with insufficient organic carbon sources. Nevertheless, in situ identification of autotrophic denitrifying communities in reactors remains challenging. Here, a process combining micro-electrolysis and autotrophic denitrification with high nitrate removal efficiency was presented. Two batch reactors were fed organic-free nitrate influent, with H(13)CO3(-) and H(12)CO3(-) as inorganic carbon sources. DNA-based stable-isotope probing (DNA-SIP) was used to obtain molecular evidence for autotrophic denitrifying communities. The results showed that the nirS gene was strongly labeled by H(13)CO3(-), demonstrating that the inorganic carbon source was assimilated by autotrophic denitrifiers. High-throughput sequencing and clone library analysis identified Thiobacillus-like bacteria as the most dominant autotrophic denitrifiers. However, 88% of nirS genes cloned from the (13)C-labeled "heavy" DNA fraction showed low similarity with all culturable denitrifiers. These findings provided functional and taxonomical identification of autotrophic denitrifying communities, facilitating application of autotrophic denitrification process for wastewater treatment.

  19. Identification of triclosan-degrading bacteria in a triclosan enrichment culture using stable isotope probing.

    Science.gov (United States)

    Lee, Do Gyun; Cho, Kun-Ching; Chu, Kung-Hui

    2014-02-01

    Triclosan, a widely used antimicrobial agent, is an emerging contaminant in the environment. Despite its antimicrobial character, biodegradation of triclosan has been observed in pure cultures, soils and activated sludge. However, little is known about the microorganisms responsible for the degradation in mixed cultures. In this study, active triclosan degraders in a triclosan-degrading enrichment culture were identified using stable isotope probing (SIP) with universally (13)C-labeled triclosan. Eleven clones contributed from active microorganisms capable of uptake the (13)C in triclosan were identified. None of these clones were similar to known triclosan-degraders/utilizers. These clones distributed among α-, β-, or γ-Proteobacteria: one belonging to Defluvibacter (α-Proteobacteria), seven belonging to Alicycliphilus (β-Proteobacteria), and three belonging to Stenotrophomonas (γ-Proteobacteria). Successive additions of triclosan caused a significant shift in the microbial community structure of the enrichment culture, with dominant ribotypes belonging to the genera Alicycliphilus and Defluvibacter. Application of SIP has successfully identified diverse uncultivable triclosan-degrading microorganisms in an activated sludge enrichment culture. The results of this study not only contributed to our understanding of the microbial ecology of triclosan biodegradation in wastewater, but also suggested that triclosan degraders are more phylogenetically diverse than previously reported.

  20. In situ stable isotope probing of phosphate-solubilizing bacteria in the hyphosphere.

    Science.gov (United States)

    Wang, Fei; Shi, Ning; Jiang, Rongfeng; Zhang, Fusuo; Feng, Gu

    2016-03-01

    This study used a [(13)C]DNA stable isotope probing (SIP) technique to elucidate a direct pathway for the translocation of (13)C-labeled photoassimilate from maize plants to extraradical mycelium-associated phosphate-solubilizing bacteria (PSB) that mediate the mineralization and turnover of soil organic phosphorus (P) in the hyphosphere. Inoculation with PSB alone did not provide any benefit to maize plants but utilized the added phytate-P to their own advantage, while inoculation with Rhizophagus irregularis alone significantly promoted shoot biomass and P content compared with the control. However, compared with both sole inoculation treatments, combined inoculation with PSB and R. irregularis in the hyphosphere enhanced organic P mineralization and increased microbial biomass P in the soil. There was no extra benefit to plant P uptake but the hyphal growth of R. irregularis was reduced, suggesting that PSB benefited from the arbuscular mycorrhizal (AM) fungal mycelium and competed for soil P with the fungus. The combination of T-RFLP (terminal restriction fragment length polymorphism) analysis with a clone library revealed that one of the bacteria that actively assimilated carbon derived from pulse-labeled maize plants was Pseudomonas alcaligenes (Pseudomonadaceae) that was initially inoculated into the hyphosphere soil. These results provide the first in situ demonstration of the pathway underlying the carbon flux from plants to the AM mycelium-associated PSB, and the PSB assimilated the photosynthates exuded by the fungus and promoted mineralization and turnover of organic P in the soil.

  1. DNA-based stable isotope probing enables the identification of active bacterial endophytes in potatoes.

    Science.gov (United States)

    Rasche, Frank; Lueders, Tillmann; Schloter, Michael; Schaefer, Sabine; Buegger, Franz; Gattinger, Andreas; Hood-Nowotny, Rebecca C; Sessitsch, Angela

    2009-03-01

    A (13)CO2 (99 atom-%, 350 ppm) incubation experiment was performed to identify active bacterial endophytes in two cultivars of Solanum tuberosum, cultivars Desirée and Merkur. We showed that after the assimilation and photosynthetic transformation of (13)CO2 into (13)C-labeled metabolites by the plant, the most directly active, cultivar specific heterotrophic endophytic bacteria that consume these labeled metabolite scan be identified by DNA stable isotope probing (DNA-SIP).Density-resolved DNA fractions obtained from SIP were subjected to 16S rRNA gene-based community analysis using terminal restriction fragment length polymorphism analysis and sequencing of generated gene libraries.Community profiling revealed community compositions that were dominated by plant chloroplast and mitochondrial 16S rRNA genes for the 'light' fractions of (13)CO2-incubated potato cultivars and of potato cultivars not incubated with (13)CO2. In the 'heavy' fractions of the (13)CO2-incubated endophyte DNA, a bacterial 492-bp terminal restriction fragment became abundant, which could be clearly identified as Acinetobacter and Acidovorax spp. in cultivars Merkur and Desirée,respectively, indicating cultivar-dependent distinctions in (13)C-label flow. These two species represent two common potato endophytes with known plant-beneficial activities.The approach demonstrated the successful detection of active bacterial endophytes in potato. DNA-SIP therefore offers new opportunities for exploring the complex nature of plant-microbe interactions and plant-dependent microbial metabolisms within the endosphere.

  2. Anaerobic carboxydotrophic bacteria in geothermal springs identified using stable isotope probing

    Directory of Open Access Journals (Sweden)

    Allyson Lee Brady

    2015-09-01

    Full Text Available Carbon monoxide (CO is a potential energy and carbon source for thermophilic bacteria in geothermal environments. Geothermal sites ranging in temperature from 45–65°C were investigated for the presence and activity of anaerobic CO-oxidizing bacteria. Anaerobic CO oxidation potentials were measured at up to 48.9 µmoles CO day-1 g (wet weight-1 within 5 selected sites. Active anaerobic carboxydotrophic bacteria were identified using 13CO DNA stable isotope probing (SIP combined with pyrosequencing of 16S rRNA genes amplified from labeled DNA. Bacterial communities identified in heavy DNA fractions were predominated by Firmicutes, which comprised up to 95% of all sequences in 13CO incubations. The predominant bacteria that assimilated 13C derived from CO were closely related (>98% to genera of known carboxydotrophs including Thermincola, Desulfotomaculum, Thermolithobacter and Carboxydocella, although a few species with lower similarity to known bacteria were also found that may represent previously unconfirmed CO-oxidizers. While the distribution was variable, many of the same OTUs were identified across sample sites from different temperature regimes. These results show that bacteria capable of using CO as a carbon source are common in geothermal springs, and that thermophilic carboxydotrophs are probably already quite well known from cultivation studies.

  3. Novel Phenanthrene-Degrading Bacteria Identified by DNA-Stable Isotope Probing.

    Directory of Open Access Journals (Sweden)

    Longfei Jiang

    Full Text Available Microorganisms responsible for the degradation of phenanthrene in a clean forest soil sample were identified by DNA-based stable isotope probing (SIP. The soil was artificially amended with either 12C- or 13C-labeled phenanthrene, and soil DNA was extracted on days 3, 6 and 9. Terminal restriction fragment length polymorphism (TRFLP results revealed that the fragments of 219- and 241-bp in HaeIII digests were distributed throughout the gradient profile at three different sampling time points, and both fragments were more dominant in the heavy fractions of the samples exposed to the 13C-labeled contaminant. 16S rRNA sequencing of the 13C-enriched fraction suggested that Acidobacterium spp. within the class Acidobacteria, and Collimonas spp. within the class Betaproteobacteria, were directly involved in the uptake and degradation of phenanthrene at different times. To our knowledge, this is the first report that the genus Collimonas has the ability to degrade PAHs. Two PAH-RHDα genes were identified in 13C-labeled DNA. However, isolation of pure cultures indicated that strains of Staphylococcus sp. PHE-3, Pseudomonas sp. PHE-1, and Pseudomonas sp. PHE-2 in the soil had high phenanthrene-degrading ability. This emphasizes the role of a culture-independent method in the functional understanding of microbial communities in situ.

  4. Preliminary study of microscale zircon oxygen isotopes for Dabie-Sulu metamorphic rocks: Ion probe in situ analyses

    Institute of Scientific and Technical Information of China (English)

    CHEN Daogong; Deloule Etienne; CHENG Hao; XIA Qunke; WU Yuanbao

    2003-01-01

    151 in situ analyses of oxygen isotopes were carried out by ion micro-probe for zircons from 8 localities of HP-UHP metamorphic rocks including eclogites in the Dabie-Sulu terrane. The results show significant heterogeneity inδ18O values, with variation in different rocks from -8.5‰ to +9.7‰ and within one sample from 2‰ to 12‰. No measurable difference inδ18O was observed between protolith magmatic (detrital) zircons and metamorphic recrystallized zircons within analytical uncertainties from the ion micro-probe measurements. This indicates that the metamorphic zircons have inherited the oxygen isotopic compositions of protolith zircons despite the HP to UHP metamorphism. According to their protolith ages from zircon U-Pb in situ dating by the same ion micro-probe, two groups of oxygen isotope composition are recognized, with one having δ18O values of 6‰-7‰ for old protolith of 1.9-2.5 Ga ages and the other 0‰-2‰ for young protolith of 0.7-0.8 Ga ages. The latter anomalously lowδ18O values of zircons indicate that the magma has had the obvious involvement of meteoric water when forming the young protolith of high-grade metamorphic rocks. This may be correlated with the snowball Earth event occurring in South China and the world elsewhere during the Neoproterozoic.

  5. {Stable isotope probing of the physical and biological controls that influence the fate and isotopic composition of carbon derived from the terrestrial methane sink }

    Science.gov (United States)

    Maxfield, P. J.; Hornibrook, E. R. C.; Dildar, N.; Evershed, R. P.

    2009-04-01

    Methane oxidizing bacteria (Methanotrophs) occur in every soil order, and are an important sink for atmospheric CH4 in well aerated soils. The quantity of C cycled via methanotrophic bacteria in soils is globally significant (Le Mer et al., 2001) yet the fate of methane derived carbon remains largely unknown and unquantified. There is generally good agreement regarding the magnitude of the soil CH4 sink determined by methane flux measurements and process modeling. More poorly characterised aspects of the soil CH4 sink include: (i) the physical and biological controls that influence the mechanism of CH4 oxidation in soils; (ii) the fate of oxidized CH4 carbon; (iii) the proportion of C from CH4 oxidation that is sequestered as organic C or released as CO2 (iv) the magnitude of kinetic isotope effects (KIEs) associated with high affinity methanotrophy in soils and the potential influence on the stable carbon isotope composition of atmospheric CH4. This research combines multiple stable isotope analytical approaches to investigate the magnitude, mechanism and pathways of the terrestrial methane sink. Principally 13CH4 stable isotope labeling techniques (Stable isotope probing; SIP) have been used to characterize and quantify methanotrophic populations in a range of different soils (Maxfield et al., 2006). Following 13CH4-incubations soil cores were removed for compound-specific C isotope analyses. Identification and quantification of methanotrophs was effectively achieved via the analysis of 13C-labelled phospholipid fatty acids (PLFAs) to link bacterial structure and function. It was also possible to identify the predominant controls influencing the active methanotrophic populations in both grassland and woodland soils (Maxfield et al., 2008). SIP can be combined with further isotopic analyses to facilitate a broader study of methanotroph C uptake and CH4 derived C sequestration. As SIP facilitates taxonomic assignments of the soil microorganisms involved in CH4 C

  6. C-13 Stable Isotope Probing of Biostimulation Experiments to Identify Acetate Utilizers

    Science.gov (United States)

    Jaffe, P. R.; Tan, H.; Kerkhof, L.; McGuinness, L.; Peacock, A.; Long, P. E.

    2011-12-01

    In order to determine which microorganisms take up acetate during biostimulation and how the uptake of acetate by specific organisms, especially Geobacter species, changes over time, a 120-day column biostimulation experiment was performed. A total of eight columns were loaded with Rifle sediments and operated under continuous flow conditions using Rifle groundwater, amended with 3 mM C-12 acetate. At regular time intervals, C-12 acetate flow into a specific column was switched to C-13 acetate. That column was then operated under C-13 acetate amendment for 36 hours before it was sacrificed for detailed geochemical and microbiological analyses. Column operation started under iron reduction (based on the measured Fe(II) in the column effluent), while sulfate reduction (based on removal of sulfate between influent and outflow), was noted at about 25 days of operation. The microbial characterization consisted of phospholipid fatty acid analysis (PLFA) and stable isotope probing (SIP). All microbial characterization was done to differentiate between the C-12 and C-13 incorporation into the biomass. Results showed that there was a differentiation between the community that was taking up acetate actively throughout the 120 days of operation and the overall microbial community. Of interest was that the fraction of Geobacter population remained fairly constant throughout the duration of the experiment, as well as its acetate uptake. Results also showed that of the acetate incorporated into the overall biomass, about 40% was incorporated into Geobacter biomass. These results are key for the proper numerical simulations of biostimulation via acetate amendment and the biostimulation of Geobacter.

  7. Nutrient amendments in soil DNA stable isotope probing experiments reduce the observed methanotroph diversity.

    Science.gov (United States)

    Cébron, Aurélie; Bodrossy, Levente; Stralis-Pavese, Nancy; Singer, Andrew C; Thompson, Ian P; Prosser, James I; Murrell, J Colin

    2007-02-01

    Stable isotope probing (SIP) can be used to analyze the active bacterial populations involved in a process by incorporating 13C-labeled substrate into cellular components such as DNA. Relatively long incubation times are often used with laboratory microcosms in order to incorporate sufficient 13C into the DNA of the target organisms. Addition of nutrients can be used to accelerate the processes. However, unnatural concentrations of nutrients may artificially change bacterial diversity and activity. In this study, methanotroph activity and diversity in soil was examined during the consumption of 13CH4 with three DNA-SIP experiments, using microcosms with natural field soil water conditions, the addition of water, and the addition of mineral salts solution. Methanotroph population diversity was studied by targeting 16S rRNA and pmoA genes. Clone library analyses, denaturing gradient gel electrophoresis fingerprinting, and pmoA microarray hybridization analyses were carried out. Most methanotroph diversity (type I and type II methanotrophs) was observed in non-amended SIP microcosms. Although this treatment probably best reflected the in situ environmental conditions, one major disadvantage of this incubation was that the incorporation of 13CH4 was slow and some cross-feeding of 13C occurred, thereby leading to labeling of nonmethanotroph microorganisms. Conversely, microcosms supplemented with mineral salts medium exhibited rapid consumption of 13CH4, resulting in the labeling of a less diverse population of only type I methanotrophs. DNA-SIP incubations using water-amended microcosms yielded faster incorporation of 13C into active methanotrophs while avoiding the cross-feeding of 13C.

  8. Precision mass measurements for studies of nucleosynthesis via the rapid neutron-capture process Penning-trap mass measurements of neutron-rich cadmium and caesium isotopes

    CERN Document Server

    AUTHOR|(CDS)2085660; Litvinov, Yuri A.; Kreim, Susanne

    Although the theory for the rapid neutron-capture process (r-process) was developed more than 55 years ago, the astrophysical site is still under a debate. Theoretical studies predict that the r-process path proceeds through very neutron-rich nuclei with very asymmetric proton- to-neutron ratios. Knowledge about the properties of neutron-rich isotopes found in similar regions of the nuclear chart and furthermore suitable for r-process studies is still little or even not existing. The basic nuclear properties such as binding energies, half-lives, neutron-induced or neutron-capture reaction cross-sections, play an important role in theoretical simulations and can vary or even drastically alternate results of these studies. Therefore, a considerable effort was put forward to access neutron-rich isotopes at radioactive ion-beam facilities like ISOLDE at CERN. The goal of this PhD thesis is to describe the experimental work done for the precision mass measurements of neutron-rich cadmium (129−131 Cd) and caesium...

  9. Probing Protein 3D Structures and Conformational Changes Using Electrochemistry-Assisted Isotope Labeling Cross-Linking Mass Spectrometry

    Science.gov (United States)

    Zheng, Qiuling; Zhang, Hao; Wu, Shiyong; Chen, Hao

    2016-05-01

    This study presents a new chemical cross-linking mass spectrometry (MS) method in combination with electrochemistry and isotope labeling strategy for probing both protein three-dimensional (3D) structures and conformational changes. For the former purpose, the target protein/protein complex is cross-linked with equal mole of premixed light and heavy isotope labeled cross-linkers carrying electrochemically reducible disulfide bonds (i.e., DSP-d0 and DSP-d8 in this study, DSP = dithiobis[succinimidyl propionate]), digested and then electrochemically reduced followed with online MS analysis. Cross-links can be quickly identified because of their reduced intensities upon electrolysis and the presence of doublet isotopic peak characteristics. In addition, electroreduction converts cross-links into linear peptides, facilitating MS/MS analysis to gain increased information about their sequences and modification sites. For the latter purpose of probing protein conformational changes, an altered procedure is adopted, in which the protein in two different conformations is cross-linked using DSP-d0 and DSP-d8 separately, and then the two protein samples are mixed in 1:1 molar ratio. The merged sample is subjected to digestion and electrochemical mass spectrometric analysis. In such a comparative cross-linking experiment, cross-links could still be rapidly recognized based on their responses to electrolysis. More importantly, the ion intensity ratios of light and heavy isotope labeled cross-links reveal the conformational changes of the protein, as exemplified by examining the effect of Ca2+ on calmodulin conformation alternation. This new cross-linking MS method is fast and would have high value in structural biology.

  10. Combining metagenomics with metaproteomics and stable isotope probing reveals metabolic pathways used by a naturally occurring marine methylotroph.

    Science.gov (United States)

    Grob, Carolina; Taubert, Martin; Howat, Alexandra M; Burns, Oliver J; Dixon, Joanna L; Richnow, Hans H; Jehmlich, Nico; von Bergen, Martin; Chen, Yin; Murrell, J Colin

    2015-10-01

    A variety of culture-independent techniques have been developed that can be used in conjunction with culture-dependent physiological and metabolic studies of key microbial organisms in order to better understand how the activity of natural populations influences and regulates all major biogeochemical cycles. In this study, we combined deoxyribonucleic acid-stable isotope probing (DNA-SIP) with metagenomics and metaproteomics to characterize an uncultivated marine methylotroph that actively incorporated carbon from (13) C-labeled methanol into biomass. By metagenomic sequencing of the heavy DNA, we retrieved virtually the whole genome of this bacterium and determined its metabolic potential. Through protein-stable isotope probing, the RuMP cycle was established as the main carbon assimilation pathway, and the classical methanol dehydrogenase-encoding gene mxaF, as well as three out of four identified xoxF homologues were found to be expressed. This proof-of-concept study is the first in which the culture-independent techniques of DNA-SIP and protein-SIP have been used to characterize the metabolism of a naturally occurring Methylophaga-like bacterium in the marine environment (i.e. Methylophaga thiooxydans L4) and thus provides a powerful approach to access the genome and proteome of uncultivated microbes involved in key processes in the environment.

  11. Field-Scale Stable-Isotope Probing of Active Methanotrophs in a Landfill-Cover Soil

    Science.gov (United States)

    Schroth, M. H.; Henneberger, R.; Chiri, E.

    2012-12-01

    The greenhouse gas methane (CH4) is an important contributor to global climate change. While its atmospheric concentration is increasing, a large portion of produced CH4 never reaches the atmosphere, but is consumed by aerobic methane-oxidizing bacteria (MOB). The latter are ubiquitous in soils and utilize CH4 as sole source of energy and carbon. Among other methods, MOB may be differentiated based on characteristic phospholipid fatty acids (PLFA). Stable-isotope probing (SIP) on PLFA has been widely applied to identify active members of MOB communities in laboratory incubation studies, but results are often difficult to extrapolate to the field. Thus, novel field-scale approaches are needed to link activity and identity of MOB in their natural environment. We present results of field experiments in which we combined PLFA-SIP with gas push-pull tests (GPPTs) to label active MOB at the field-scale while simultaneously quantifying CH4 oxidation activity. During a SIP-GPPT, a mixture of reactive (here 13CH4, O2) and non-reactive tracer gases (e.g., Ar, Ne, He) is injected into the soil at a location of interest. Thereafter, gas flow is reversed and the gas mixture diluted with soil air is extracted from the same location and sampled periodically. Rate constants for CH4 oxidation can be calculated by analyzing breakthrough curves of 13CH4 and a suitable non-reactive tracer gas. SIP-GPPTs were performed in a landfill-cover soil, and feasibility of this novel approach was tested at several locations along a gradient of MOB activity and soil temperature. Soil samples were collected before and after SIP-GPPTs, total PLFA were extracted, and incorporation of 13C in the polar lipid fraction was analyzed. Potential CH4 oxidation rates derived from SIP-GPPTs were similar to those derived from regular GPPTs (using unlabeled CH4) performed at the same locations prior to SIP-GPPTs, indicating that application of 13CH4 did not adversely affect bacterial CH4 oxidation rates. Rates

  12. Reverse and Multiple Stable Isotope Probing to Study Bacterial Metabolism and Interactions at the Single Cell Level.

    Science.gov (United States)

    Wang, Yun; Song, Yizhi; Tao, Yifan; Muhamadali, Howbeer; Goodacre, Royston; Zhou, Ning-Yi; Preston, Gail M; Xu, Jian; Huang, Wei E

    2016-10-04

    The interactions between microorganisms driven by substrate metabolism and energy flow are important to shape diversity, abundance, and structure of a microbial community. Single cell technologies are useful tools for dissecting the functions of individual members and their interactions in microbial communities. Here, we developed a novel Raman stable isotope probing (Raman-SIP), which uses Raman microspectroscopy coupled with reverse and D2O colabeling to study metabolic interactions in a two-species community consisting of Acinetobacter baylyi ADP1 and Escherichia coli DH5α-GFP. This Raman-SIP approach is able to detect carbon assimilation and general metabolic activity simultaneously. Taking advantage of Raman shift of single cell Raman spectra (SCRS) mediated by incorporation of stable-isotopic substrates, Raman-SIP with reverse labeling has been applied to detect initially (13)C-labeled bands of ADP1 SCRS reverting back to (12)C positions in the presence of (12)C citrate. Raman-SIP with D2O labeling has been employed to probe metabolic activity of single cells without the need of cell replication. Our results show that E. coli alone in minimal medium with citrate as the sole carbon source had no metabolic activity, but became metabolically active in the presence of ADP1. Mass spectrometry-based metabolite footprint analysis suggests that putrescine and phenylalanine excreted by ADP1 cells may support the metabolic activity of E. coli. This study demonstrates that Raman-SIP with reverse labeling would be a useful tool to probe metabolism of any carbon substrate, overcoming limitations when stable isotopic substrates are not readily available. It is also found that Raman-SIP with D2O labeling is a sensitive and reliable approach to distinguish metabolically active cells but not quiescent cells. This novel approach extends the application of Raman-SIP and demonstrates its potential application as a valuable strategic approach for probing cellular metabolism

  13. Use of stable isotope probing to assess the fate of emerging contaminants degraded by white-rot fungus.

    Science.gov (United States)

    Badia-Fabregat, Marina; Rosell, Mònica; Caminal, Glòria; Vicent, Teresa; Marco-Urrea, Ernest

    2014-05-01

    The widespread of emerging contaminants in the environment and their potential impact on humans is a matter of concern. White-rot fungi are cosmopolitan organisms able to remove a wide range of pharmaceuticals and personal care products (PPCP) through cometabolism (i.e. laccases and peroxidases) or detoxification mechanisms (i.e. cytochrome P450 system). However, the use of PPCP as carbon source for these organisms is largely unexplored. Here, we used carbon stable isotope tracer experiments to assess the fate of anti-inflammatory diclofenac (DCF) and UV filter benzophenone-3 (BP3) during degradation by Trametes versicolor. The comparison between carbon isotopic composition of emitted carbon dioxide from 13C-labelled DCF ([acetophenyl ring-13C6]-DCF) and 13C-BP3 ([phenyl-13C6]-BP3) versus their 12C-homologue compounds showed mineralization of about 45% and 10% of the 13C contained in their respective molecules after 9 days of incubation. The carbon isotopic composition of the bulk biomass and the application of amino acid-stable isotope probing (SIP) allowed distinguishing between incorporation of 13C from BP3 into amino acids, which implies the use of this emerging contaminant as carbon source, and major intracellular accumulation of 13C from DCF without implying the transformation of its labelled phenyl ring into anabolic products. A mass balance of 13C in different compartments over time provided a comprehensive picture of the fate of DCF and BP3 across their different transformation processes. This is the first report assessing biodegradation of PPCP by SIP techniques and the use of emerging contaminants as carbon source for amino acid biosynthesis.

  14. Stable-isotope probe of nano-scale mineral-fluid redox interactions

    Energy Technology Data Exchange (ETDEWEB)

    Kavner, Abby [Univ. of California, Los Angeles, CA (United States)

    2014-11-26

    The project examined how stable isotopes fractionate at an aqueous/solid interface during electrochemical reduction reactions. Measurements in a wide variety of metal deposition systems including Fe, Zn, Li, Mo, and Cu, have led to observations of large isotope fractionations which strongly vary as a function of rate and temperature. For the Fe, Zn, and Li systems, our electrochemical deposition methods provide the largest single-pass fractionation factors that are observed for these systems. Based on these and other experiments and theory showing and predicting significant and rate-dependent fractionations of isotopes at reacting interfaces, we have developed a simple statistical mechanics framework that predicts the kinetic isotope effect accompanying phase transformations in condensed systems. In addition, we have begun to extend our studies of mineral-fluid redox interactions to high pressures and temperatures in the diamond anvil cell. We performed a series of experiments to determine solubilities of Cu and Ni at elevated pressure and temperature conditions relevant to ore-formation.

  15. Probing the homogeneity of the isotopic composition and molar mass of the ‘Avogadro’-crystal

    Science.gov (United States)

    Pramann, Axel; Lee, Kyoung-Seok; Noordmann, Janine; Rienitz, Olaf

    2015-12-01

    Improved measurements on silicon crystal samples highly enriched in the 28Si isotope (known as ‘Si28’ or AVO28 crystal material) have been carried out at PTB to investigate local isotopic variations in the original crystal. This material was used for the determination of the Avogadro constant NA and therefore plays an important role in the upcoming redefinition of the SI units kilogram and mole, using fundamental constants. Subsamples of the original crystal have been extensively studied over the past few years at the National Research Council (NRC, Canada), the National Metrology Institute of Japan (NMIJ, Japan), the National Institute of Standards and Technology (NIST, USA), the National Institute of Metrology (NIM, People’s Republic of China), and multiple times at PTB. In this study, four to five discrete, but adjacent samples were taken from three distinct axial positions of the crystal to obtain a more systematic and comprehensive understanding of the distribution of the isotopic composition and molar mass throughout the crystal. Moreover, improved state-of-the-art techniques in the experimental measurements as well as the evaluation approach and the determination of the calibration factors were utilized. The average molar mass of the measured samples is M  =  27.976 970 12(12) g mol-1 with a relative combined uncertainty uc,rel(M)  =  4.4 ×10-9. This value is in astounding agreement with the values of single samples measured and published by NIST, NMIJ, and PTB. With respect to the associated uncertainties, no significant variations in the molar mass and the isotopic composition as a function of the sample position in the boule were observed and thus could not be traced back to an inherent property of the crystal. This means that the crystal is not only ‘homogeneous’ with respect to molar mass but also has predominantly homogeneous distribution of the three stable Si isotopes.

  16. Studies on focal alveolar bone healing with technetium (Tc)-99m labeled methylene diphosphonate and gold-collimated cadmium telluride probe

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchimochi, M.; Hosain, F.; Engelke, W.; Zeichner, S.J.; Ruttimann, U.E.; Webber, R.L. (National Institute of Dental Research, Bethesda, MD (USA))

    1991-01-01

    The benefit of using a collimator for a miniaturized cadmium telluride probe was evaluated by monitoring the bone-healing processes for 13 weeks after the induction of small iatrogenic alveolar bone lesions in one side of the mandible in beagles. Technetium (Tc)-99m labeled methylene diphosphonate (200 to 300 MBq, 5.1 to 8.1 mCi, in a solution of 0.5 to 1 ml, intravenously) was used as a bone-seeking radiopharmaceutical. The radioactivity over the bone lesion (L) and the contralateral normal site (C) in the mandible were measured between 1.5 and 2 hours after injection of the tracer, and the activity ratio L/C served as an index of relative bone uptake. A study of six dogs revealed that the healing response to a hemispheric bone defect of 2 mm diameter in the cortical bone could not be detected by an uncollimated probe, and in a repeated study in two dogs the use of a gold collimator (5 mm in diameter, 5 mm in length) did not increase the L/C ratio significantly. A second study in six dogs with 5 mm lesions showed that although systematic trends in the time courses of the L/C ratio obtained both with and without the collimator could be demonstrated, the L/C ratio of collimated versus uncollimated measurements was significantly (p less than 0.005) increased. In three of the latter six dogs, abscesses developed after 9 weeks, leading to a second increase (p less than 0.05) of the L/C ratio with collimation compared with the noninflammation group; without collimation no significant (p greater than 0.15) difference between the two groups could be demonstrated.

  17. Isotopic and impurity element probes of mesoscale chemical dynamics at mineral fluid interfaces

    Science.gov (United States)

    DePaolo, D. J.

    2012-12-01

    Mesoscale interactions control important Earth processes including the growth of minerals from aqueous solutions and silicate liquids, the diffusion of ions in solids and silicate liquids, and the solid-state deformation and recrystallization that constitutes metamorphism. Most of these processes are typically understood from the classical side in terms of macroscopic physical and thermodynamic properties and classical kinetics, and from the molecular side in terms of single molecule or nearest-neighbor interactions. However, in many cases the controlling processes occur at intermediate scales of both length and time, and involve complex interactions among multiple chemical species. A major limitation has been in characterizing and modeling the dynamic processes that lead to the macroscopic properties and behavior. Advanced microscopy techniques allow phase changes, for example, to be monitored at high resolution, and this capability continues to improve. However, other important information about the phase changes, such as the molecular exchange fluxes between phases and the detailed mechanisms of reaction, are not revealed by microscopy. High-resolution isotopic characterization now allows the molecular exchange fluxes to be quantified, and models suggest that the incorporation of impurity elements is directly tied to these fluxes. One of the main advances is that precise isotopic measurements have recently been extended to include major stoichiometric cations such as Ca, Mg, Fe, and K, as well as key impurity elements such as U, Cd, Mo, and Sr. Isotopic analysis at the nano- to microscale would further clarify the detailed dynamics of mineral chemistry controls but are not yet possible except in a few instances. Impurity element concentrations are more easily measured at these small scales, and they are a key bridge between isotopic measurements and microscopy.Other limitations to advancing our knowledge of the chemical and isotopic effects associated with

  18. RNA-stable-isotope probing shows utilization of carbon from inulin by specific bacterial populations in the rat large bowel.

    Science.gov (United States)

    Tannock, Gerald W; Lawley, Blair; Munro, Karen; Sims, Ian M; Lee, Julian; Butts, Christine A; Roy, Nicole

    2014-04-01

    Knowledge of the trophisms that underpin bowel microbiota composition is required in order to understand its complex phylogeny and function. Stable-isotope ((13)C)-labeled inulin was added to the diet of rats on a single occasion in order to detect utilization of inulin-derived substrates by particular members of the cecal microbiota. Cecal digesta from Fibruline-inulin-fed rats was collected prior to (0 h) and at 6, 12, 18 and 24 h following provision of the [(13)C]inulin diet. RNA was extracted from these cecal specimens and fractionated in isopycnic buoyant density gradients in order to detect (13)C-labeled nucleic acid originating in bacterial cells that had metabolized the labeled dietary constituent. RNA extracted from specimens collected after provision of the labeled diet was more dense than 0-h RNA. Sequencing of 16S rRNA genes amplified from cDNA obtained from these fractions showed that Bacteroides uniformis, Blautia glucerasea, Clostridium indolis, and Bifidobacterium animalis were the main users of the (13)C-labeled substrate. Culture-based studies of strains of these bacterial species enabled trophisms associated with inulin and its hydrolysis products to be identified. B. uniformis utilized Fibruline-inulin for growth, whereas the other species used fructo-oligosaccharide and monosaccharides. Thus, RNA-stable-isotope probing (RNA-SIP) provided new information about the use of carbon from inulin in microbiota metabolism.

  19. Detection of Sialic Acid-Utilising Bacteria in a Caecal Community Batch Culture Using RNA-Based Stable Isotope Probing

    Directory of Open Access Journals (Sweden)

    Wayne Young

    2015-03-01

    Full Text Available Sialic acids are monosaccharides typically found on cell surfaces and attached to soluble proteins, or as essential components of ganglioside structures that play a critical role in brain development and neural transmission. Human milk also contains sialic acid conjugated to oligosaccharides, glycolipids, and glycoproteins. These nutrients can reach the large bowel where they may be metabolised by the microbiota. However, little is known about the members of the microbiota involved in this function. To identify intestinal bacteria that utilise sialic acid within a complex intestinal community, we cultured the caecal microbiota from piglets in the presence of 13C-labelled sialic acid. Using RNA-based stable isotope probing, we identified bacteria that consumed 13C-sialic acid by fractionating total RNA in isopycnic buoyant density gradients followed by 16S rRNA gene analysis. Addition of sialic acid caused significant microbial community changes. A relative rise in Prevotella and Lactobacillus species was accompanied by a corresponding reduction in the genera Escherichia/Shigella, Ruminococcus and Eubacterium. Inspection of isotopically labelled RNA sequences suggests that the labelled sialic acid was consumed by a wide range of bacteria. However, species affiliated with the genus Prevotella were clearly identified as the most prolific users, as solely their RNA showed significantly higher relative shares among the most labelled RNA species. Given the relevance of sialic acid in nutrition, this study contributes to a better understanding of their microbial transformation in the intestinal tract with potential implications for human health.

  20. Identification of metabolically active methanogens in anaerobic digester by DNA Stable-Isotope Probing using 13C-acetate

    Directory of Open Access Journals (Sweden)

    V. Gowdaman

    2015-04-01

    Full Text Available Anaerobic digestion is gaining enormous attention due to the ability to covert organic wastes into biogas, an alternative sustainable energy. Methanogenic community plays a significant role in biogas production and also for proficient functioning of the anaerobic digester. Therefore, this study was carried out to investigate the methanogen diversity of a food waste anaerobic digester. After endogenous respiration, the digester samples were supplemented with isotopes of acetate to enrich methanogen population, and were analyzed using DNA-SIP (Stable-Isotope Probing. Following separation and fractionation of heavy (13C and light (12C DNA, PCR amplification was carried out using archaeal 16S rRNA gene followed by DGGE analysis. Sequencing of the prominent DGGE bands revealed the dominance of Methanocorpusculum labreanum species belonging to hydrogenotrophic Methanomicrobiales, which can produce methane in the presence of H2/CO2 and requires acetate for its growth. This is the first instance where Methanocorpusculum labreanum is being reported as a dominant species in an anaerobic digester operative on food waste.

  1. A novel method to characterize bacterial communities affected by carbon source and electricity generation in microbial fuel cells using stable isotope probing and Illumina sequencing.

    Science.gov (United States)

    Song, Yang; Xiao, Li; Jayamani, Indumathy; He, Zhen; Cupples, Alison M

    2015-01-01

    Stable isotope probing and high throughput sequencing were used to characterize the microbial communities involved in carbon uptake in microbial fuel cells at two levels of electricity generation. With acetate, the dominant phylotypes involved in carbon uptake included Geobacter and Rhodocyclaceae. With glucose, both Enterobacteriaceae and Geobacter were dominant.

  2. Identification of glucose-fermenting bacteria present in an in vitro model of the human intestine by RNA-stable isotope probing

    NARCIS (Netherlands)

    Egert, M.; Graaf, A.A. de; Maathuis, A.; Waard, P. de; Plugge, C.M.; Smidt, H.; Deutz, N.E.P.; Dijkema, C.; Vos, W.M. de; Venema, K.

    2007-01-01

    16S rRNA-based stable isotope probing (SIP) and nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling were used to identify bacteria fermenting glucose under conditions simulating the human intestine. The TIM-2 in vitro model of the human intestine was inoculated with a GI tract mi

  3. Identification of glucose-fermenting bacteria present in an in-vitro model of the human inetstine by RNA-stable isotope probing

    NARCIS (Netherlands)

    Egert, M.G.G.; Graaf, de A.A.; Maathuis, A.; Waard, de P.; Plugge, C.M.; Smidt, H.; Deutz, N.E.P.; Dijkema, C.; Vos, de W.M.; Venema, K.

    2007-01-01

    16S rRNA-based stable isotope probing (SIP) and nuclear magnetic resonance (NMR) spectroscopy-based metabolic profiling were used to identify bacteria fermenting glucose under conditions simulating the human intestine. The TIM-2 in vitro model of the human intestine was inoculated with a GI tract mi

  4. Linking phylogenetic identities of bacteria to starch fermentation in an in vitro model of the large intestine by RNA-based stable isotope probing

    NARCIS (Netherlands)

    Kovatcheva-Datchary, P.; Egert, M.; Maathuis, A.; Rajilić-Stojanović, M.; Graaf, A.A.de; Smidt, H.; Vos, W.M.de; Venema, K.

    2009-01-01

    Summary Carbohydrates, including starches, are an important energy source for humans, and are known for their interactions with the microbiota in the digestive tract. Largely, those interactions are thought to promote human health. Using 16S ribosomal RNA (rRNA)-based stable isotope probing (SIP), w

  5. Identification of glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal plant by stable isotope probing.

    Science.gov (United States)

    Nielsen, Jeppe Lund; Nguyen, Hien; Meyer, Rikke Louise; Nielsen, Per Halkjær

    2012-07-01

    Microbiology in wastewater treatment has mainly been focused on problem-causing filamentous bacteria or bacteria directly involved in nitrogen and phosphorus removal, and to a lesser degree on flanking groups, such as hydrolysing and fermenting bacteria. However, these groups constitute important suppliers of readily degradable substrates for the overall processes in the plant. This study aimed to identify glucose-fermenting bacteria in a full-scale enhanced biological phosphorus removal (EBPR) wastewater treatment plant (WWTP), and to determine their abundance in similar WWTPs. Glucose-fermenting micro-organisms were identified by an in situ approach using RNA-based stable isotope probing. Activated sludge was incubated anaerobically with (13)C(6)-labelled glucose, and (13)C-enriched rRNA was subsequently reverse-transcribed and used to construct a 16S rRNA gene clone library. Phylogenetic analysis of the library revealed the presence of two major phylogenetic groups of gram-positive bacteria affiliating with the genera Tetrasphaera, Propionicimonas (Actinobacteria), and Lactococcus and Streptococcus (Firmicutes). Specific oligonucleotide probes were designed for fluorescence in situ hybridization (FISH) to specifically target the glucose-fermenting bacteria identified in this study. The combination of FISH with microautoradiography confirmed that Tetrasphaera, Propionicimonas and Streptococcus were the dominant glucose fermenters. The probe-defined fermenters were quantified in 10 full-scale EBPR plants and averaged 39 % of the total biovolume. Tetrasphaera and Propionicimonas were the most abundant glucose fermenters (average 33 and 4 %, respectively), while Streptococcus and Lactococcus were present only in some WWTPs (average 1 and 0.4 %, respectively). Thus the population of actively metabolizing glucose fermenters seems to occupy a relatively large component of the total biovolume.

  6. The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

    Science.gov (United States)

    Batenburg, A. M.; Schuck, T. J.; Baker, A. K.; Zahn, A.; Brenninkmeijer, C. A. M.; Röckmann, T.

    2012-05-01

    More than 450 air samples that were collected in the upper troposphere - lower stratosphere (UTLS) region by the CARIBIC aircraft (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) have been analyzed for molecular hydrogen (H2) mixing ratios (χ(H2)) and H2 isotopic composition (deuterium content, δD). More than 120 of the analyzed samples contained air from the lowermost stratosphere (LMS). These show that χ(H2) does not vary appreciably with O3-derived height above the thermal tropopause (TP), whereas δD does increase with height. The isotope enrichment is caused by H2 production and destruction processes that enrich the stratospheric H2 reservoir in deuterium (D); the exact shapes of the profiles are mainly determined by mixing of stratospheric with tropospheric air. Tight negative correlations are found between δD and the mixing ratios of methane (χ(CH4)) and nitrous oxide (χ(N2O)), as a result of the relatively long lifetimes of these three species. The correlations are described by δD[‰]=-0.35 · χ(CH4)[ppb]+768 and δD[‰]=-1.90· χ(N2O)[ppb]+745. These correlations are similar to previously published results and likely hold globally for the LMS. Samples that were collected from the Indian subcontinent up to 40° N before, during and after the summer monsoon season show no significant seasonal change in χ(H2), but δD is up to 12.3‰ lower in the July, August and September monsoon samples. This δD decrease is correlated with the χ(CH4) increase in these samples. The significant correlation with χ(CH4) and the absence of a perceptible χ(H2) increase that accompanies the δD decrease indicates that microbial production of very D-depleted H2 in the wet season may contribute to this phenomenon. Some of the samples have very high χ(H2) and very low δD values, which indicates a pollution effect. Aircraft engine exhaust plumes are a suspected cause, since the effect mostly occurs in samples

  7. Strong Water Isotopic Anomalies in the Martian Atmosphere: Probing Current and Ancient Reservoirs

    Science.gov (United States)

    Villanueva, G. L.; Mumma, M. J.; Novak, R. E.; Käufl, H. U.; Hartogh, P.; Encrenaz, T.; Tokunaga, A.; Khayat, A.; Smith, M. D.

    2015-01-01

    We measured maps of atmospheric water (H2O) and its deuterated form (HDO) across the martian globe, showing strong isotopic anomalies and a significant high deuterium/hydrogen (D/H) enrichment indicative of great water loss. The maps sample the evolution of sublimation from the north polar cap, revealing that the released water has a representative D/H value enriched by a factor of about 7 relative to Earth's ocean [Vienna standard mean ocean water (VSMOW)]. Certain basins and orographic depressions show even higher enrichment, whereas high-altitude regions show much lower values (1 to 3 VSMOW). Our atmospheric maps indicate that water ice in the polar reservoirs is enriched in deuterium to at least 8 VSMOW, which would mean that early Mars (4.5 billion years ago) had a global equivalent water layer at least 137 meters deep.

  8. Probing the diversity of chloromethane-degrading bacteria by comparative genomics and isotopic fractionation.

    Science.gov (United States)

    Nadalig, Thierry; Greule, Markus; Bringel, Françoise; Keppler, Frank; Vuilleumier, Stéphane

    2014-01-01

    Chloromethane (CH3Cl) is produced on earth by a variety of abiotic and biological processes. It is the most important halogenated trace gas in the atmosphere, where it contributes to ozone destruction. Current estimates of the global CH3Cl budget are uncertain and suggest that microorganisms might play a more important role in degrading atmospheric CH3Cl than previously thought. Its degradation by bacteria has been demonstrated in marine, terrestrial, and phyllospheric environments. Improving our knowledge of these degradation processes and their magnitude is thus highly relevant for a better understanding of the global budget of CH3Cl. The cmu pathway, for chloromethane utilisation, is the only microbial pathway for CH3Cl degradation elucidated so far, and was characterized in detail in aerobic methylotrophic Alphaproteobacteria. Here, we reveal the potential of using a two-pronged approach involving a combination of comparative genomics and isotopic fractionation during CH3Cl degradation to newly address the question of the diversity of chloromethane-degrading bacteria in the environment. Analysis of available bacterial genome sequences reveals that several bacteria not yet known to degrade CH3Cl contain part or all of the complement of cmu genes required for CH3Cl degradation. These organisms, unlike bacteria shown to grow with CH3Cl using the cmu pathway, are obligate anaerobes. On the other hand, analysis of the complete genome of the chloromethane-degrading bacterium Leisingera methylohalidivorans MB2 showed that this bacterium does not contain cmu genes. Isotope fractionation experiments with L. methylohalidivorans MB2 suggest that the unknown pathway used by this bacterium for growth with CH3Cl can be differentiated from the cmu pathway. This result opens the prospect that contributions from bacteria with the cmu and Leisingera-type pathways to the atmospheric CH3Cl budget may be teased apart in the future.

  9. Probing the diversity of chloromethane-degrading bacteria by comparative genomics and isotopic fractionation

    Directory of Open Access Journals (Sweden)

    Thierry eNADALIG

    2014-10-01

    Full Text Available Chloromethane (CH3Cl is produced on earth by a variety of abiotic and biological processes. It is the most important halogenated trace gas in the atmosphere, where it contributes to ozone destruction. Current estimates of the global CH3Cl budget are uncertain and suggest that microorganisms might play a more important role in degrading atmospheric CH3Cl than previously thought. Its degradation by bacteria has been demonstrated in marine, terrestrial and phyllospheric environments. Improving our knowledge of these degradation processes and its magnitude is thus highly relevant for a better understanding of the global budget of CH3Cl.The cmu pathway, for chloromethane utilisation, is the only microbial pathway for CH3Cl degradation elucidated so far, and was characterised in detail in aerobic methylotrophic Alphaproteobacteria. Here, we reveal the potential of using a two-pronged approach involving a combination of comparative genomics and isotopic fractionation during CH3Cl degradation to newly address the question of the diversity of chloromethane-degrading bacteria in the environment.Analysis of available bacterial genome sequences reveals that several bacteria not yet known to degrade CH3Cl contain part or all of the complement of cmu genes required for CH3Cl degradation. These organisms, unlike bacteria shown to grow with CH3Cl using the cmu pathway, are obligate anaerobes. On the other hand, analysis of the complete genome of the chloromethane-degrading bacterium Leisingera methylohalidivorans showed that this bacterium does not contain cmu genes. Isotope fractionation experiments with L. methylohalidivorans suggest that the unknown pathway used by this bacterium for growth with CH3Cl can be differentiated from the cmu pathway. This result opens the prospect that contributions from bacteria with the cmu and Leisingera-type pathways to the atmospheric CH3Cl budget may be teased apart in the future.

  10. The stable isotopic composition of molecular hydrogen in the tropopause region probed by the CARIBIC aircraft

    Directory of Open Access Journals (Sweden)

    A. M. Batenburg

    2012-05-01

    Full Text Available More than 450 air samples that were collected in the upper troposphere – lower stratosphere (UTLS region by the CARIBIC aircraft (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container have been analyzed for molecular hydrogen (H2 mixing ratios (χ(H2 and H2 isotopic composition (deuterium content, δD.

    More than 120 of the analyzed samples contained air from the lowermost stratosphere (LMS. These show that χ(H2 does not vary appreciably with O3-derived height above the thermal tropopause (TP, whereas δD does increase with height. The isotope enrichment is caused by H2 production and destruction processes that enrich the stratospheric H2 reservoir in deuterium (D; the exact shapes of the profiles are mainly determined by mixing of stratospheric with tropospheric air. Tight negative correlations are found between δD and the mixing ratios of methane (χ(CH4 and nitrous oxide (χ(N2O, as a result of the relatively long lifetimes of these three species. The correlations are described by δD[‰]=−0.35 · χ(CH4[ppb]+768 and δD[‰]=−1.90· χ(N2O[ppb]+745. These correlations are similar to previously published results and likely hold globally for the LMS.

    Samples that were collected from the Indian subcontinent up to 40° N before, during and after the summer monsoon season show no significant seasonal change in χ(H2, but δD is up to 12.3‰ lower in the July, August and September monsoon samples. This δD decrease is correlated with the χ(CH4 increase in these samples. The significant correlation with χ(CH4 and the absence of a perceptible χ(H2 increase that accompanies the δD decrease indicates that microbial production of

  11. Protein Structure-Function Correlation in Living Human Red Blood Cells Probed by Isotope Exchange-based Mass Spectrometry.

    Science.gov (United States)

    Narayanan, Sreekala; Mitra, Gopa; Muralidharan, Monita; Mathew, Boby; Mandal, Amit K

    2015-12-01

    To gain insight into the underlying mechanisms of various biological events, it is important to study the structure-function correlation of proteins within cells. Structural probes used in spectroscopic tools to investigate protein conformation are similar across all proteins. Therefore, structural studies are restricted to purified proteins in vitro and these findings are extrapolated in cells to correlate their functions in vivo. However, due to cellular complexity, in vivo and in vitro environments are radically different. Here, we show a novel way to monitor the structural transition of human hemoglobin upon oxygen binding in living red blood cells (RBCs), using hydrogen/deuterium exchange-based mass spectrometry (H/DX-MS). Exploiting permeability of D2O across cell membrane, the isotope exchange of polypeptide backbone amide hydrogens of hemoglobin was carried out inside RBCs and monitored using matrix-assisted laser desorption ionization mass spectrometry (MALDI-MS). To explore the conformational transition associated with oxygenation of hemoglobin in vivo, the isotope exchange kinetics was simplified using the method of initial rates. RBC might be considered as an in vivo system of pure hemoglobin. Thus, as a proof-of-concept, the observed results were correlated with structural transition of hemoglobin associated with its function established in vitro. This is the first report on structural changes of a protein upon ligand binding in its endogenous environment. The proposed method might be applicable to proteins in their native state, irrespective of location, concentration, and size. The present in-cell approach opens a new avenue to unravel a plethora of biological processes like ligand binding, folding, and post-translational modification of proteins in living cells.

  12. Microbial food web mapping: linking carbon cycling and community structure in soils through pyrosequencing enabled stable isotope probing

    Energy Technology Data Exchange (ETDEWEB)

    Buckley, Daniel H. [Cornell Univ., Ithaca, NY (United States)

    2015-03-15

    Soil represents a massive reservoir of active carbon and climate models vary dramatically in predicting how this carbon will respond to climate change over the coming century. A major cause of uncertainty is that we still have a very limited understand the microorganisms that dominate the soil carbon cycle. The vast majority of soil microbes cannot be cultivated in the laboratory and the diversity of organisms and enzymes that participate in the carbon cycle is staggeringly complex. We have developed a new toolbox for exploring the carbon cycle and the metabolic and ecological characteristics of uncultivated microorganisms. The high-resolution nucleic acid stable isotope probing approach that we have developed makes it possible to characterize microbial carbon cycling dynamics in soil. The approach allows us to track multiple 13C-labeled substrates into thousands of microbial taxa over time. Using this approach we have discovered several major lineages of uncultivated microorganisms that participate in cellulose metabolism and are found widely in soils (including Verrucomicrobia and Chloroflexi, which have not previously been implicated as major players in the soil carbon cycle). Furthermore, isotopic labelling of nucleic acids enables community genomics and permits genome fragment binning for a majority of these cellulolytic microorganisms allowing us to explore the metabolic underpinnings of cellulose degradation. This approach has allowed us to describe unexpected dynamics of carbon metabolism with different microbial taxa exhibiting characteristic patterns of carbon substrate incorporation, indicative of distinct ecological strategies. The data we describe allows us to characterize the activity of novel microorganisms as they occur in the environment and these data provide a basis for understanding how the physiological traits of discrete microorganisms sum to govern the complex responses of the soil carbon cycle.

  13. Stable isotope probing and Raman spectroscopy for monitoring carbon flow in a food chain and revealing metabolic pathway.

    Science.gov (United States)

    Li, Mengqiu; Huang, Wei E; Gibson, Christopher M; Fowler, Patrick W; Jousset, Alexandre

    2013-02-05

    Accurately measuring carbon flows is a challenge for understanding processes such as diverse intracellular metabolic pathways and predator-prey interactions. Combined with stable isotope probing (SIP), single-cell Raman spectroscopy was demonstrated for the first time to link the food chain from carbon substrate to bacterial prey up to predators at the single-cell level in a quantitative and nondestructive manner. Escherichia coli OP50 with different (13)C content, which were grown in a mixture of (12)C- and fully carbon-labeled (13)C-glucose (99%) as a sole carbon source, were fed to the nematode. The (13)C signal in Caenorhabditis elegans was proportional to the (13)C content in E. coli. Two Raman spectral biomarkers (Raman bands for phenylalanine at 1001 cm(-1) and thymine at 747 cm(-1) Raman bands), were used to quantify the (13)C content in E. coli and C. elegans over a range of 1.1-99%. The phenylalanine Raman band was a suitable biomarker for prokaryotic cells and thymine Raman band for eukaryotic cells. A biochemical mechanism accounting for the Raman red shifts of phenylalanine and thymine in response to (13)C-labeling is proposed in this study and is supported by quantum chemical calculation. This study offers new insights of carbon flow via the food chain and provides a research tool for microbial ecology and investigation of biochemical pathways.

  14. Probing the metabolic network in bloodstream-form Trypanosoma brucei using untargeted metabolomics with stable isotope labelled glucose.

    Directory of Open Access Journals (Sweden)

    Darren J Creek

    2015-03-01

    Full Text Available Metabolomics coupled with heavy-atom isotope-labelled glucose has been used to probe the metabolic pathways active in cultured bloodstream form trypomastigotes of Trypanosoma brucei, a parasite responsible for human African trypanosomiasis. Glucose enters many branches of metabolism beyond glycolysis, which has been widely held to be the sole route of glucose metabolism. Whilst pyruvate is the major end-product of glucose catabolism, its transamination product, alanine, is also produced in significant quantities. The oxidative branch of the pentose phosphate pathway is operative, although the non-oxidative branch is not. Ribose 5-phosphate generated through this pathway distributes widely into nucleotide synthesis and other branches of metabolism. Acetate, derived from glucose, is found associated with a range of acetylated amino acids and, to a lesser extent, fatty acids; while labelled glycerol is found in many glycerophospholipids. Glucose also enters inositol and several sugar nucleotides that serve as precursors to macromolecule biosynthesis. Although a Krebs cycle is not operative, malate, fumarate and succinate, primarily labelled in three carbons, were present, indicating an origin from phosphoenolpyruvate via oxaloacetate. Interestingly, the enzyme responsible for conversion of phosphoenolpyruvate to oxaloacetate, phosphoenolpyruvate carboxykinase, was shown to be essential to the bloodstream form trypanosomes, as demonstrated by the lethal phenotype induced by RNAi-mediated downregulation of its expression. In addition, glucose derivatives enter pyrimidine biosynthesis via oxaloacetate as a precursor to aspartate and orotate.

  15. The key microorganisms for anaerobic degradation of pentachlorophenol in paddy soil as revealed by stable isotope probing

    Energy Technology Data Exchange (ETDEWEB)

    Tong, Hui [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); University of Chinese Academy of Sciences, Beijing 100049 (China); Liu, Chengshuai [State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550009 (China); Li, Fangbai, E-mail: cefbli@soil.gd.cn [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China); Luo, Chunling [Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640 (China); Chen, Manjia; Hu, Min [Guangdong Key Laboratory of Agricultural Environment Pollution Integrated Control, Guangdong Institute of Eco-Environmental and Soil Sciences, Guangzhou 510650 (China)

    2015-11-15

    Highlights: • SIP suggested that Dechloromonas can mineralize PCP in soil. • Methanosaeta and Methanocella acquired PCP-derived carbon. • Lactate enhanced microbial degradation of PCP in soil. - Abstract: Pentachlorophenol (PCP) is a common residual persistent pesticide in paddy soil and has resulted in harmful effect on soil ecosystem. The anaerobic microbial transformation of PCP, therefore, has been received much attentions, especially the functional microbial communities for the reductive transformation. However, the key functional microorganisms for PCP mineralization in the paddy soil still remain unknown. In this work, DNA-based stable isotope probing (SIP) was applied to explore the key microorganisms responsible for PCP mineralization in paddy soil. The SIP results indicated that the dominant bacteria responsible for PCP biodegradation belonged to the genus Dechloromonas of the class β-Proteobacteria. In addition, the increased production of {sup 13}CH{sub 4} and {sup 13}CO{sub 2} indicated that the addition of lactate enhanced the rate of biodegradation and mineralization of PCP. Two archaea classified as the genera of Methanosaeta and Methanocella of class Methanobacteria were enriched in the heavy fraction when with lactate, whereas no archaea was detected in the absence of lactate. These findings provide direct evidence for the species of bacteria and archaea responsible for anaerobic PCP or its breakdown products mineralization and reveal a new insight into the microorganisms linked with PCP degradation in paddy soil.

  16. Intraclade heterogeneity in nitrogen utilization by marine prokaryotes revealed using stable isotope probing coupled with tag sequencing (Tag-SIP

    Directory of Open Access Journals (Sweden)

    Michael Morando

    2016-12-01

    Full Text Available Nitrogen can greatly influence the structure and productivity of microbial communities through its relative availability and form. However, roles of specific organisms in the uptake of different nitrogen species remain poorly characterized. Most studies seeking to identify agents of assimilation have been correlative, indirectly linking activity measurements (e.g., nitrate uptake with the presence or absence of biological markers, particularly functional genes and their transcripts. Evidence is accumulating of previously underappreciated functional diversity in major microbial subpopulations, which may confer physiological advantages under certain environmental conditions leading to ecotype divergence. This microdiversity further complicates our view of genetic variation in environmental samples requiring the development of more targeted approaches. Here, next-generation tag sequencing was successfully coupled with stable isotope probing (Tag-SIP to assess the ability of individual phylotypes to assimilate a particular N source. Our results provide the first direct evidence of nitrate utilization by organisms thought to lack the genes required for this process including the heterotrophic clades SAR11 and the Archaeal Marine Group II (MG-II. We also provide new direct evidence of in situ nitrate utilization by the cyanobacterium Prochlorococcus in support of recent findings. Furthermore, these results revealed widespread functional heterogeneity, i.e. different levels of N assimilation within clades, likely reflecting niche partitioning by ecotypes. The addition of nitrate utilization to ecosystem and ecosystem models by these globally dominant clades will likely improve the mechanistic accuracy of these models.

  17. Isotope effects in liquid water probed by transmission mode x-ray absorption spectroscopy at the oxygen K-edge

    Science.gov (United States)

    Schreck, Simon; Wernet, Philippe

    2016-09-01

    The effects of isotope substitution in liquid water are probed by x-ray absorption spectroscopy at the O K-edge as measured in transmission mode. Confirming earlier x-ray Raman scattering experiments, the D2O spectrum is found to be blue shifted with respect to H2O, and the D2O spectrum to be less broadened. Following the earlier interpretations of UV and x-ray Raman spectra, the shift is related to the difference in ground-state zero-point energies between D2O and H2O, while the difference in broadening is related to the difference in ground-state vibrational zero-point distributions. We demonstrate that the transmission-mode measurements allow for determining the spectral shapes with unprecedented accuracy. Owing in addition to the increased spectral resolution and signal to noise ratio compared to the earlier measurements, the new data enable the stringent determination of blue shift and broadening in the O K-edge x-ray absorption spectrum of liquid water upon isotope substitution. The results are compared to UV absorption data, and it is discussed to which extent they reflect the differences in zero-point energies and vibrational zero-point distributions in the ground-states of the liquids. The influence of the shape of the final-state potential, inclusion of the Franck-Condon structure, and differences between liquid H2O and D2O resulting from different hydrogen-bond environments in the liquids are addressed. The differences between the O K-edge absorption spectra of water from our transmission-mode measurements and from the state-of-the-art x-ray Raman scattering experiments are discussed in addition. The experimentally extracted values of blue shift and broadening are proposed to serve as a test for calculations of ground-state zero-point energies and vibrational zero-point distributions in liquid H2O and D2O. This clearly motivates the need for new calculations of the O K-edge x-ray absorption spectrum of liquid water.

  18. Multiple DNA extractions coupled with stable-isotope probing of anthracene-degrading bacteria in contaminated soil.

    Science.gov (United States)

    Jones, Maiysha D; Singleton, David R; Sun, Wei; Aitken, Michael D

    2011-05-01

    In many of the DNA-based stable-isotope probing (SIP) studies published to date in which soil communities were investigated, a single DNA extraction was performed on the soil sample, usually using a commercial DNA extraction kit, prior to recovering the (13)C-labeled (heavy) DNA by density-gradient ultracentrifugation. Recent evidence suggests, however, that a single extraction of a soil sample may not lead to representative recovery of DNA from all of the organisms in the sample. To determine whether multiple DNA extractions would affect the DNA yield, the eubacterial 16S rRNA gene copy number, or the identification of anthracene-degrading bacteria, we performed seven successive DNA extractions on the same aliquot of contaminated soil either untreated or enriched with [U-(13)C]anthracene. Multiple extractions were necessary to maximize the DNA yield and 16S rRNA gene copy number from both untreated and anthracene-enriched soil samples. Sequences within the order Sphingomonadales, but unrelated to any previously described genus, dominated the 16S rRNA gene clone libraries derived from (13)C-enriched DNA and were designated "anthracene group 1." Sequences clustering with Variovorax spp., which were also highly represented, and sequences related to the genus Pigmentiphaga were newly associated with anthracene degradation. The bacterial groups collectively identified across all seven extracts were all recovered in the first extract, although quantitative PCR analysis of SIP-identified groups revealed quantitative differences in extraction patterns. These results suggest that performing multiple DNA extractions on soil samples improves the extractable DNA yield and the number of quantifiable eubacterial 16S rRNA gene copies but have little qualitative effect on the identification of the bacterial groups associated with the degradation of a given carbon source by SIP.

  19. Ubiquitous dissolved inorganic carbon assimilation by marine bacteria in the Pacific Northwest coastal ocean as determined by stable isotope probing.

    Directory of Open Access Journals (Sweden)

    Suzanne DeLorenzo

    Full Text Available In order to identify bacteria that assimilate dissolved inorganic carbon (DIC in the northeast Pacific Ocean, stable isotope probing (SIP experiments were conducted on water collected from 3 different sites off the Oregon and Washington coasts in May 2010, and one site off the Oregon Coast in September 2008 and March 2009. Samples were incubated in the dark with 2 mM (13C-NaHCO(3, doubling the average concentration of DIC typically found in the ocean. Our results revealed a surprising diversity of marine bacteria actively assimilating DIC in the dark within the Pacific Northwest coastal waters, indicating that DIC fixation is relevant for the metabolism of different marine bacterial lineages, including putatively heterotrophic taxa. Furthermore, dark DIC-assimilating assemblages were widespread among diverse bacterial classes. Alphaproteobacteria, Gammaproteobacteria, and Bacteroidetes dominated the active DIC-assimilating communities across the samples. Actinobacteria, Betaproteobacteria, Deltaproteobacteria, Planctomycetes, and Verrucomicrobia were also implicated in DIC assimilation. Alteromonadales and Oceanospirillales contributed significantly to the DIC-assimilating Gammaproteobacteria within May 2010 clone libraries. 16S rRNA gene sequences related to the sulfur-oxidizing symbionts Arctic96BD-19 were observed in all active DIC assimilating clone libraries. Among the Alphaproteobacteria, clones related to the ubiquitous SAR11 clade were found actively assimilating DIC in all samples. Although not a dominant contributor to our active clone libraries, Betaproteobacteria, when identified, were predominantly comprised of Burkholderia. DIC-assimilating bacteria among Deltaproteobacteria included members of the SAR324 cluster. Our research suggests that DIC assimilation is ubiquitous among many bacterial groups in the coastal waters of the Pacific Northwest marine environment and may represent a significant metabolic process.

  20. Cadmium-free sugar-chain-immobilized fluorescent nanoparticles containing low-toxicity ZnS-AgInS2 cores for probing lectin and cells.

    Science.gov (United States)

    Shinchi, Hiroyuki; Wakao, Masahiro; Nagata, Nonoka; Sakamoto, Masaya; Mochizuki, Eiko; Uematsu, Taro; Kuwabata, Susumu; Suda, Yasuo

    2014-02-19

    Sugar chains play a significant role in various biological processes through sugar chain-protein and sugar chain-sugar chain interactions. To date, various tools for analyzing sugar chains biofunctions have been developed. Fluorescent nanoparticles (FNPs) functionalized with carbohydrate, such as quantum dots (QDs), are an attractive imaging tool for analyzing carbohydrate biofunctions in vitro and in vivo. Most FNPs, however, consist of highly toxic elements such as cadmium, tellurium, selenium, and so on, causing problems in long-term bioimaging because of their cytotoxicity. In this study, we developed cadmium-free sugar-chain-immobilized fluorescent nanoparticles (SFNPs) using ZnS-AgInS2 (ZAIS) solid solution nanoparticles (NPs) of low or negligible toxicity as core components, and investigated their bioavailability and cytotoxicity. SFNPs were prepared by mixing our originally developed sugar-chain-ligand conjugates with ZAIS/ZnS core/shell NPs. In binding experiments with lectin, the obtained ZAIS/ZnS SFNPs interacted with an appropriate lectin to give specific aggregates, and their binding interaction was visually and/or spectroscopically detected. In addition, these SFNPs were successfully utilized for cytometry analysis and cellular imaging in which the cell was found to possess different sugar-binding properties. The results of the cytotoxicity assay indicated that SFNPs containing ZAIS/ZnS have much lower toxicity than those containing cadmium. These data strongly suggest that our designed SFNPs can be widely utilized in various biosensing applications involved in carbohydrates.

  1. Probing Archean lithosphere using the Lu-Hf isotope systematics of peridotite xenoliths from Somerset Island kimberlites, Canada

    Science.gov (United States)

    Schmidberger, Stefanie S.; Simonetti, Antonio; Francis, Don; Gariépy, Clément

    2002-04-01

    A knowledge of the Hf isotopic composition of the subcontinental lithosphere beneath Archean cratons is essential to constrain the Hf isotope budget of the Earth's mantle. Hf isotopic measurements were obtained by MC-ICP-MS for a suite of refractory peridotite xenoliths and constituent garnets from the Nikos kimberlite (100 Ma) on Somerset Island in order to constrain the isotopic composition and age of the lithosphere beneath the northern Canadian craton. The low-temperature Nikos peridotites (Somerset lithosphere, are characterized by higher 176Lu/ 177Hf ratios (0.03-0.05) and Hf isotopic values ( 176Hf/ 177Hf (0.1Ga)=0.28296-0.28419) than the deep-seated high-temperature peridotites (>1100°C; 0.004-0.03, 0.28265-0.28333, respectively). These differences in Hf isotope signatures suggest that shallow and deep subcontinental lithosphere beneath Somerset Island represent isotopically distinct domains and do not share a common petrogenetic history. The Lu-Hf isotope systematics of the shallow low-temperature peridotites define a positively sloped line that plot along a 2.8 Ga reference isochron. A number of these peridotites are characterized by highly radiogenic Hf isotopic compositions suggestive of long-term radiogenic ingrowth (billions of years). These findings are consistent with an interpretation that the shallow Somerset lithosphere (to depths of ˜150 km) stabilized in the Archean. The majority of the high-temperature peridotites plot closer to the composition of the host kimberlite. Although the observed isotopic variation may be attributed in part to kimberlite-related Hf addition, it is possible that these deep-seated xenoliths represent younger mantle. The superchondritic 176Lu/ 177Hf ratios observed for a number of the shallow low-temperature peridotites indicate strong fractionation of Lu and Hf, suggesting mantle root formation in the garnet stability field (depths >80 km). The Hf isotope compositions for the Somerset low-temperature peridotites

  2. Amino acid precursors from a simulated lower atmosphere of Titan, Experiments of cosmic ray energy source with 13C- and 18O-stable isotope probing mass spectrometry

    CERN Document Server

    Taniuchi, Toshinori; Kobayashi, Kensei

    2013-01-01

    The organic haze of aerosols that shrouds the Saturnian moon Titan has previously been studied by both observations and laboratory simulation experiments. Here we report the abiotic formation of amino acid precursors in complex organic molecules during experimental simulation of the environment near Titan's surface with proton irradiation. Pyrolysis of the organic molecules formed in the simulated Titan atmosphere by proton irradiation at 600 degree-C yielded compounds that contained HCN and NH3. These experimental results are consistent with the molecular information obtained by pyrolysis gas chromatography-mass spectrometry (pyrolysis GC-MS) of samples collected by the Huygens probe to Titan. Scanning electron microscopy (SEM) and three-dimensional atomic force microscopy (AFM) images of the irradiation products reveal nanometer-scale filaments and globules in complex amorphous structures (approximately 1000 Da). Isotope probing experiments by matrix-assisted laser desorption ionization time-of-flight mass ...

  3. Probing site-specific 13C/15N-isotope enrichment of spider silk with liquid-state NMR spectroscopy.

    Science.gov (United States)

    Shi, Xiangyan; Yarger, Jeffery L; Holland, Gregory P

    2013-05-01

    Solid-state nuclear magnetic resonance (NMR) has been extensively used to elucidate spider silk protein structure and dynamics. In many of these studies, site-specific isotope enrichment is critical for designing particular NMR methods for silk structure determination. The commonly used isotope analysis techniques, isotope-ratio mass spectroscopy and liquid/gas chromatography-mass spectroscopy, are typically not capable of providing the site-specific isotope information for many systems because an appropriate sample derivatization method is not available. In contrast, NMR does not require any sample derivatization or separation prior to analysis. In this article, conventional liquid-state (1)H NMR was implemented to evaluate incorporation of (13)C/(15)N-labeled amino acids in hydrolyzed spider dragline silk. To determine site-specific (13)C and (15)N isotope enrichments, an analysis method was developed to fit the (1)H-(13)C and (1)H-(15)N J-splitting (J CH and J NH) (1)H NMR peak patterns of hydrolyzed silk fiber. This is demonstrated for Nephila clavipes spiders, where [U-(13)C3,(15)N]-Ala and [1-(13)C,(15)N]-Gly were dissolved in their water supplies. Overall, contents for Ala and Gly isotopomers are extracted for these silk samples. The current methodology can be applied to many fields where site-specific tracking of isotopes is of interest.

  4. The preferential growth of branched GDGT source microorganisms under aerobic conditions in peat revealed by stable isotope probing experiments

    Science.gov (United States)

    Huguet, Arnaud; Meador, Travis B.; Laggoun-Défarge, Fatima; Könneke, Martin; Derenne, Sylvie; Hinrichs, Kai-Uwe

    2016-04-01

    Branched glycerol dialkyl glycerol tetraether (brGDGTs) membrane lipids are widely distributed in aquatic and terrestrial environments and are being increasingly used as temperature proxies. Nevertheless, little is known regarding the microorganisms that produce these lipids, which are found in especially high abundance in the anaerobic horizons of peat bogs. We initiated stable isotope probing incubations of peat samples from a Sphagnum-dominated peatland (Jura Mountains, France) to measure the incorporation of (D)-D2O and 13C-labeled dissolved inorganic carbon (DIC) into brGDGTs, and thus gauge the activity, growth, and turnover times of their source organisms. Peat samples were collected from two adjacent sites with contrasting humidity levels (hereafter called "fen" and "bog" sites). For each site, samples from the surficial aerobic layer (acrotelm) and deeper anaerobic layer (catotelm) were collected and were incubated under both anaerobic and aerobic conditions for the acrotelm samples and only anaerobic conditions for the catotelm. The incubations were performed at 12 ° C, consistent with the mean summer air temperature at the sampling site. After two months of incubation, there was no incorporation of 13C label in brGDGTs for samples incubated under either aerobic or anaerobic conditions, showing that brGDGT-producing bacteria are heterotrophic microorganisms, as previously observed in organo-mineral soils (Weijers et al., 2011). Similarly, little to no deuterium incorporation was observed for brGDGTs isolated from anaerobically-incubated deep samples. In contrast, in the aerobic incubations of acrotelm samples from bog and fen, the weighted average δD of brGDGT core lipids (CLs) increased by up to 3332‰ and 933‰ after two months, respectively, indicating that fresh brGDGT CLs were biosynthesized at the peat surface. D incorporation into brGDGT CLs converted to production rates ranging from 30-106 ng cm-3y-1 in the aerobic acrotelm from bog and fen

  5. Use of stable isotope labeled probes to facilitate liquid chromatography/mass spectrometry based high-throughput screening of time-dependent CYP inhibitors.

    Science.gov (United States)

    Dasgupta, Malini; Tang, Weimin; Caldwell, Gary W; Yan, Zhengyin

    2010-08-15

    Inhibition curve shift is a commonly used approach for screening of time-dependent CYP inhibitors which requires parallel paired incubations to obtain two inhibition curves for comparison. For the control incubation, a test compound is co-incubated with a probe substrate in human liver microsomes (HLM) fortified with NADPH; for the time-dependent incubation (TDI), the test compound is pre-incubated with NADPH-fortified HLM followed by a secondary incubation with a probe substrate. For both incubations, enzyme activity is measured respectively by liquid chromatography/tandem mass spectrometry (LC/MS/MS) analysis of the CYP-specific metabolite, and a TDI inhibitor can be readily identified by inhibition curve shifting as a result of CYP inactivation by the test compound during the pre-incubation. In the present study, we describe an alternative approach to facilitate TDI screening in which stable isotope labeled CYP-specific probes are used for the TDI, and non-labeled substrates are included in the control incubation. Because CYP-specific metabolites produced in the TDI are stable isotope labeled, two sets of incubation samples can be combined and then simultaneously analyzed by LC/MS/MS in the same batch run to reduce the run time. This new method has been extensively validated using both a number of known competitive and TDI inhibitors specific to five most common CYPs such as 1A2, 2C9, 2C19, 2D6, and 3A4. The assay is performed in a 96-well format and can be fully automated. Compared to the traditional method, this approach in combination with sample pooling and a short LC/MS/MS gradient significantly enhances the throughput of TDI screening and thus can be easily implemented in drug discovery to evaluate a large number of compounds without adding additional resource.

  6. Comparison of hydrogen isotope retention for tungsten probes in LHD vacuum vessel during the experimental campaigns in 2011 and 2012

    Energy Technology Data Exchange (ETDEWEB)

    Oya, Y., E-mail: syoya@ipc.shizuoka.ac.jp [Graduate School of Science, Shizuoka University, Shizuoka (Japan); Masuzaki, S.; Tokitani, M. [National Institute for Fusion Science, Gifu (Japan); Sato, M.; Toda, K.; Uchimura, H. [Graduate School of Science, Shizuoka University, Shizuoka (Japan); Yoshida, N.; Watanabe, H. [Institute for Applied Mechanics, Kyushu University, Kasuga, Fukuoka (Japan); Yamauchi, Y.; Hino, T. [Graduate School of Engineering, Hokkaido University, Sapporo (Japan); Miyamoto, M. [Department of Material Science, Shimane University, Matsue, Shimane (Japan); Hatano, Y. [Hydrogen Isotope Research Center, University of Toyama, Toyama (Japan); Okuno, K. [Graduate School of Science, Shizuoka University, Shizuoka (Japan)

    2014-10-15

    Highlights: • Hydrogen isotope retention enhancement for W exposed to LHD 2011 and 2012 campaigns were evaluated. • Large hydrogen retention enhancement was derived for all the samples compared to that for pure W. • The carbon-dominated mixed-material layer would control the hydrogen isotope retention for all the area except for erosion-dominated area. • The chemical structure for carbon-dominant mixed-material layer may govern the H and D retention enhancement for most area. - Abstract: To evaluate hydrogen isotope retention enhancement in W by plasma exposure, the stress relieved tungsten samples were placed at three or four different positions, namely PI (sputtering erosion dominated area), DP (deposition dominated area), HL (Higher heat load area) and ER (erosion dominated area) during 2011 (15th) or 2012 (16th) plasma experiment campaign in Large Helical Device (LHD) at National Institute for Fusion Science (NIFS), Japan and were exposed to ∼6700 shots of hydrogen plasma in a 2011 plasma experiment campaign and ∼5000 shots in a 2012 plasma campaign. Thereafter, additional 1.0 keV deuterium ion implantation was performed to evaluate the change of hydrogen isotope retention capacity by plasma exposure. It was found that more than 50 times of hydrogen retention enhancement for DP sample was derived compared to that for pure W. In especially, the carbon-dominated mixed-material layer would control the hydrogen isotope retention for all the area except for erosion-dominated area, indicating that the chemical structure for carbon-dominant mixed-material layer would govern the H and D retention enhancement for most area by long-term plasma exposure. Therefore, the surface area for carbon material would be one of key issues for the determination of hydrogen isotope retention in first wall, even if all tungsten first walls will be used.

  7. Isotopic chirality

    Energy Technology Data Exchange (ETDEWEB)

    Floss, H.G. [Univ. of Washington, Seattle, WA (United States)

    1994-12-01

    This paper deals with compounds that are chiral-at least in part, due to isotope substitution-and their use in tracing the steric course of enzyme reaction in vitro and in vivo. There are other applications of isotopically chiral compounds (for example, in analyzing the steric course of nonenzymatic reactions and in probing the conformation of biomolecules) that are important but they will not be discussed in this context.

  8. Stable isotope probing and dynamic loading experiments provide insight into the ecophysiology of novel ammonia oxidizers in rapid gravity sand filters

    DEFF Research Database (Denmark)

    Fowler, Jane; Palomo, Alejandro; Gülay, Arda

    to elucidate the differences in ecophysiology between the ammonia oxidizing clades that enable them to co-exist in this unique environment. Experiments were conducted using sand columns designed and operated to mimic the conditions in the full-scale parent RSF. RNA and DNA stable isotope probing based on 13C......Nitrification is often the dominant microbial process in rapid gravity sand filters (RSF), used to treat aerated groundwater to produce drinking water. RSFs harbor diverse microbial communities including a range of ammonia oxidizing clades; Betaproteobacteria (Nitrosomonas, Nitrosospira), Archaea......, diverse potentially ammonia oxidizing heterotrophs and abundant Nitrospira spp., recently shown to comprise both canonical nitrite oxidizing as well as complete ammonium oxidizing (comammox) types. We examined the contributions of the different ammonia oxidizers to in situ ammonia oxidation, and aimed...

  9. Carbon-13 (13C) labeling of Bacillus subtilis vegetative cells and spores: suitability for DNA stable isotope probing (DNA-SIP) of spores in soils.

    Science.gov (United States)

    Nicholson, Wayne L; Fedenko, Jeffrey; Schuerger, Andrew C

    2009-07-01

    To test the suitability of DNA stable isotope probing (DNA-SIP) for characterizing bacterial spore populations in soils, the properties of Bacillus subtilis cells and spores intensely labeled with [(13)C]glucose were characterized. Spore germination, vegetative growth rates, and sporulation efficiency were indistinguishable on glucose versus [(13)C]glucose, as were spore wet heat and UV resistance. Unlabeled and (13)C-labeled spores contained 1.0989 and 74.336 at.% (13)C, and exhibited wet densities of 1.356 and 1.365 g/ml, respectively. Chromosomal DNAs containing (12)C versus (13)C were readily separated by their different buoyant densities in cesium chloride/ethidium bromide gradients.

  10. Identifying Low pH Active and Lactate-Utilizing Taxa within Oral Microbiome Communities from Healthy Children Using Stable Isotope Probing Techniques

    Energy Technology Data Exchange (ETDEWEB)

    McLean, Jeffrey S.; Fansler, Sarah J.; Majors, Paul D.; Mcateer, Kathleen; Allen, Lisa Z.; Shirtliff, Mark E.; Lux, Renate; Shi, Wenyuan

    2012-03-05

    Many human microbial infectious diseases including dental caries are polymicrobial in nature and how these complex multi-species communities evolve from a healthy to a diseased state is not well understood. Although many health- or disease-associated oral microbes have been characterized in vitro, their physiology in vivo in the presence of the complex oral microbiome is difficult to determine with current approaches. In addition, about half of these oral species remain uncultivated to date and little is known except their 16S rRNA sequence. Lacking culture-based physiological analyses, the functional roles of uncultivated microorganisms will remain enigmatic despite their apparent disease correlation. To start addressing these knowledge gaps, we applied a novel combination of in vivo Magnetic Resonance Spectroscopy (MRS) with RNA and DNA based Stable Isotope Probing (SIP) to oral plaque communities from healthy children for temporal monitoring of carbohydrate utilization, organic acid production and identification of metabolically active and inactive bacterial species.

  11. Analysis of cytochrome P450 metabolites of arachidonic acid by stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry.

    Science.gov (United States)

    Zhu, Quan-Fei; Hao, Yan-Hong; Liu, Ming-Zhou; Yue, Jiang; Ni, Jian; Yuan, Bi-Feng; Feng, Yu-Qi

    2015-09-04

    Cytochrome P450 metabolites of arachidonic acid (AA) belong to eicosanoids and are potent lipid mediators of inflammation. It is well-known that eicosanoids play an important role in numerous pathophysiological processes. Therefore, quantitative analysis of cytochrome P450 metabolites of AA, including hydroxyeicosatetraenoic acids (HETEs), epoxyeicosatreinoic acids (EETs), and dihydroxyeicosatrienoic acids (DHETs) can provide crucial information to uncover underlying mechanisms of cytochrome P450 metabolites of AA related diseases. Herein, we developed a highly sensitive method to identify and quantify HETEs, EETs, and DHETs in lipid extracts of biological samples based on stable isotope probe labeling coupled with ultra high-performance liquid chromatography/mass spectrometry. To this end, a pair of stable isotope probes, 2-dimethylaminoethylamine (DMED) and d4-2-dimethylaminoethylamine (d4-DMED), were utilized to facilely label eicosanoids. The heavy labeled eicosanoid standards were prepared and used as internal standards for quantification to minimize the matrix and ion suppression effects in mass spectrometry analysis. In addition, the detection sensitivities of DMED labeled eicosanoids improved by 3-104 folds in standard solution and 5-138 folds in serum matrix compared with unlabeled analytes. Moreover, a good separation of eicosanoids isomers was achieved upon DMED labeling. The established method provided substantial sensitivity (limit of quantification at sub-picogram), high specificity, and broad linear dynamics range (3 orders of magnitude). We further quantified cytochrome P450 metabolites of AA in rat liver, heart, brain tissues and human serum using the developed method. The results showed that 19 eicosanoids could be distinctly detected and the contents of 11-, 15-, 16-, 20-HETE, 5,6-EET, and 14,15-EET in type 2 diabetes mellitus patients and 5-, 11-, 12-, 15-, 16-, 20-HETE, 8,9-EET, and 5,6-DHET in myeloid leukemia patients had significant changes

  12. RNA-Based Stable Isotope Probing Suggests Allobaculum spp. as Particularly Active Glucose Assimilators in a Complex Murine Microbiota Cultured In Vitro

    Science.gov (United States)

    Herrmann, Elena; Young, Wayne; Rosendale, Douglas; Reichert-Grimm, Verena; Conrad, Ralf

    2017-01-01

    RNA-based stable isotope probing (RNA-SIP) and metabolic profiling were used to detect actively glucose-consuming bacteria in a complex microbial community obtained from a murine model system. A faeces-derived microbiota was incubated under anaerobic conditions for 0, 2, and 4 h with 40 mM [U13C]glucose. Isopycnic density gradient ultracentrifugation and fractionation of isolated RNA into labeled and unlabeled fractions followed by 16S rRNA sequencing showed a quick adaptation of the bacterial community in response to the added sugar, which was dominated by unclassified Lachnospiraceae species. Inspection of distinct fractions of isotope-labeled RNA revealed Allobaculum spp. as particularly active glucose utilizers in the system, as the corresponding RNA showed significantly higher proportions among the labeled RNA. With time, the labeled sugar was used by a wider spectrum of faecal bacteria. Metabolic profiling indicated rapid fermentation of [U13C]glucose, with lactate, acetate, and propionate being the principal 13C-labeled fermentation products, and suggested that “cross-feeding” occurred in the system. RNA-SIP combined with metabolic profiling of 13C-labeled products allowed insights into the microbial assimilation of a general model substrate, demonstrating the appropriateness of this technology to study assimilation processes of nutritionally more relevant substrates, for example, prebiotic carbohydrates, in the gut microbiota of mice as a model system. PMID:28299315

  13. Compound-specific 15N stable isotope probing of N assimilation by the soil microbial biomass: a new methodological paradigm in soil N cycling

    Science.gov (United States)

    Charteris, A. F.; Knowles, T. D. J.; Michaelides, K.; Evershed, R. P.

    2015-10-01

    A compound-specific nitrogen-15 stable isotope probing (15N-SIP) technique is described which allows investigation of the fate of inorganic- or organic-N amendments to soils. The technique uses gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS) to determine the δ15N values of individual amino acids (AAs; determined as N-acetyl, O-isopropyl derivatives) as proxies of biomass protein production. The δ15N values are used together with AA concentrations to quantify N assimilation of 15N-labelled substrates by the soil microbial biomass. The utility of the approach is demonstrated through incubation experiments using inorganic 15N-labelled substrates ammonium (15NH4+) and nitrate (15NO3-) and an organic 15N-labelled substrate, glutamic acid (15N-Glu). Assimilation of all the applied substrates was undetectable based on bulk soil properties, i.e. % total N (% TN), bulk soil N isotope composition and AA concentrations, all of which remained relatively constant throughout the incubation experiments. In contrast, compound-specific AA δ15N values were highly sensitive to N assimilation, providing qualitative and quantitative insights into the cycling and fate of the applied 15N-labelled substrates. The utility of this 15N-AA-SIP technique is considered in relation to other currently available methods for investigating the microbially-mediated assimilation of nitrogenous substrates into the soil organic N pool. This approach will be generally applicable to the study of N cycling in any soil, or indeed, in any complex ecosystem.

  14. Decay properties of 68,69,70Mn: Probing collectivity up to N=44 in Fe isotopic chain

    Directory of Open Access Journals (Sweden)

    G. Benzoni

    2015-12-01

    Full Text Available The β decays Mn68→Fe68, Mn69→Fe69 and Mn70→Fe70 have been measured at the RIBF facility at RIKEN using the EURICA γ spectrometer combined with an active stopper consisting of a stack of Si detectors. The nuclei were produced as fission fragments from a beam of 238U at a bombarding energy of 345 MeV/nucleon impinging on a Be target and selected using the BigRIPS separator. Half-lives and β-delayed neutron emission probabilities have been extracted for these decays, together with first experimental information on excited states populated in 69,70Fe. The data indicate a continuously increasing deformation for Fe isotopes up to A=70. This is interpreted, as for Cr isotopes, in terms of the interplay between the quadrupole correlations of the ν1d5/2 and ν0g9/2 orbitals and the monopole component of the π0f7/2–ν0f5/2 interaction.

  15. Application of Isotope Dilution Mass Spectrometry for Reference Measurements of Cadmium. Copper, Mercury, Lead, Zinc and Methyl Mercury in Marine Sediment Sample

    Directory of Open Access Journals (Sweden)

    Vasileva E.

    2013-04-01

    Full Text Available Marine sediment was selected as a test sample for the laboratory inter-comparison studies organized by the Environment Laboratoryes of the International Atomic Energy. The analytical procedure to establish the reference values for the Cd, Cu, Hg, Methyl Hg, Pb and Zn amount contents was based on Isotope Dilution Inductively Coupled Plasma-Mass Spectrometry (ID ICP-MS applied as a primary method of measurement..The Hg and Methyl Hg determination will be detailed more specifically because of the problems encountered with this element, including sample homogeneity issues, memory effects and possible matrix effects during the ICP- MS measurement stage. Reference values, traceable to the SI, with total uncertainties of less than 2% relative expanded uncertainty (k=2 were obtained for Cd, Cu, Zn and Pb and around 5% for Hg and CH3Hg.

  16. Role of the anion in the underpotential deposition of cadmium on a Rh(111) electrode: probed by voltammetry and in situ scanning tunneling microscopy.

    Science.gov (United States)

    Ou Yang, Liang-Yueh; Bensliman, Fahd; Shue, Chia-Haw; Yang, Yaw-Chia; Zang, Ze-Haw; Wang, Li; Yau, Shueh-Lin; Yoshimoto, Soichiro; Itaya, Kingo

    2005-08-11

    In situ scanning tunneling microscopy (STM) and cyclic voltammetry (CV) were employed to examine the underpotential deposition (UPD) of cadmium on a rhodium(111) electrode in sulfuric and hydrochloric acids. The (bi)sulfate and chloride anions in the electrolytes played a main role in controlling the number and arrangement of Cd adatoms. Deposition of Cd along with hydrogen adsorption occurred near 0.1 V (vs reversible hydrogen electrode) in either 0.05 M H2SO4 or 0.1 M HCl containing 1 mM Cd(ClO4)2. These coupled processes resulted in an erroneous coverage of Cd adatoms. The process of Cd deposition shifted positively to 0.3 V and thus separated from that of hydrogen in 0.05 M H2SO4 containing 0.5 M Cd2+. The amount of charge (80 microC/cm2) for Cd deposition in 0.5 M Cd2+ implied a coverage of 0.17 for the Cd adatoms, which agreed with in situ STM results. Regardless of [Cd2+], in situ STM imaging revealed a highly ordered Rh(111)-(6 x 6)-6Cd + HSO4- or SO42- structure in sulfuric acid,. In hydrochloric acid, in situ STM discerned a (2 x 2)-Cd + Cl structure at potentials where Cd deposition commenced. STM atomic resolution showed roughly one-quarter of a monolayer of Cd adatoms were deposited, ca. 50% more than in sulfuric acid. Dynamic in situ STM imaging showed potential dependent, reversible transformations between the (6 x 6) Cd adlattices and (square root 3 x square root 7)-(bi)sulfate structure, and between (2 x 2) and (square root 7 x square root 7)R19.1 degrees -Cl structures. The fact that different Cd structures observed in H2SO4 and HCl entailed the involvement of anions in Cd deposition, i.e. (bi)sulfate and chloride anions were codeposited with Cd adatoms on Rh(111).

  17. An ultrasensitive and selective method for the determination of Ceftriaxone using cysteine capped cadmium sulfide fluorescence quenched quantum dots as fluorescence probes

    Science.gov (United States)

    Samadi, Naser; Narimani, Saeedeh

    2016-06-01

    In this paper, L-cysteine (Cys) coated CdS quantum dots (QDs) have been prepared, which have excellent water-solubility and are highly stable in aqueous solution. These QDs is proposed as sensitizers for the determination of Ceftriaxone. The quantum dot nanoparticles were structurally and optically characterized by Ultra Violet-Visible absorption Spectroscopy (UV-vis absorption spectroscopy), Fourier transform infrared spectroscopy (FT-IR spectra) and photoluminescence (PL) emission spectroscopy. High resolution transmission electron microscopy (HRTEM) confirms that the Cys-CdS QDs have a spherical structure with good crystallinity. Therefore, a new simple and selective PL analysis system was developed for the determination of Ceftriaxone (CFX). Under the optimum conditions, The response of L-Cys capped CdS QDs as the probe was linearly proportional to the concentration of Ceftriaxone ions in the range of 1.6 × 10- 9-1.1 × 10- 3 M with a correlation coefficient (R2) of 0.9902. The limit of detection of this system was found to be 1.3 nM. This method is simple, sensitive and low cost.

  18. An ultrasensitive and selective method for the determination of Ceftriaxone using cysteine capped cadmium sulfide fluorescence quenched quantum dots as fluorescence probes.

    Science.gov (United States)

    Samadi, Naser; Narimani, Saeedeh

    2016-06-15

    In this paper, l-cysteine (Cys) coated CdS quantum dots (QDs) have been prepared, which have excellent water-solubility and are highly stable in aqueous solution. These QDs is proposed as sensitizers for the determination of Ceftriaxone. The quantum dot nanoparticles were structurally and optically characterized by Ultra Violet-Visible absorption Spectroscopy (UV-vis absorption spectroscopy), Fourier transform infrared spectroscopy (FT-IR spectra) and photoluminescence (PL) emission spectroscopy. High resolution transmission electron microscopy (HRTEM) confirms that the Cys-CdS QDs have a spherical structure with good crystallinity. Therefore, a new simple and selective PL analysis system was developed for the determination of Ceftriaxone (CFX). Under the optimum conditions, The response of l-Cys capped CdS QDs as the probe was linearly proportional to the concentration of Ceftriaxone ions in the range of 1.6×10(-9)-1.1×10(-3)M with a correlation coefficient (R2) of 0.9902. The limit of detection of this system was found to be 1.3nM. This method is simple, sensitive and low cost.

  19. Bacteria capable of degrading anthracene, phenanthrene, and fluoranthene as revealed by DNA based stable-isotope probing in a forest soil.

    Science.gov (United States)

    Song, Mengke; Jiang, Longfei; Zhang, Dayi; Luo, Chunling; Wang, Yan; Yu, Zhiqiang; Yin, Hua; Zhang, Gan

    2016-05-05

    Information on microorganisms possessing the ability to metabolize different polycyclic aromatic hydrocarbons (PAHs) in complex environments helps in understanding PAHs behavior in natural environment and developing bioremediation strategies. In the present study, stable-isotope probing (SIP) was applied to investigate degraders of PAHs in a forest soil with the addition of individually (13)C-labeled phenanthrene, anthracene, and fluoranthene. Three distinct phylotypes were identified as the active phenanthrene-, anthracene- and fluoranthene-degrading bacteria. The putative phenanthrene degraders were classified as belonging to the genus Sphingomona. For anthracene, bacteria of the genus Rhodanobacter were the putative degraders, and in the microcosm amended with fluoranthene, the putative degraders were identified as belonging to the phylum Acidobacteria. Our results from DNA-SIP are the first to directly link Rhodanobacter- and Acidobacteria-related bacteria with anthracene and fluoranthene degradation, respectively. The results also illustrate the specificity and diversity of three- and four-ring PAHs degraders in forest soil, contributes to our understanding on natural PAHs biodegradation processes, and also proves the feasibility and practicality of DNA-based SIP for linking functions with identity especially uncultured microorganisms in complex microbial biota.

  20. Identifying fermenting bacteria in anoxic tidal-flat sediments by a combination of microcalorimetry and ribosome-based stable-isotope probing.

    Science.gov (United States)

    Graue, Jutta; Kleindienst, Sara; Lueders, Tillmann; Cypionka, Heribert; Engelen, Bert

    2012-07-01

    A novel approach was developed to follow the successive utilization of organic carbon under anoxic conditions by microcalorimetry, chemical analyses of fermentation products and stable-isotope probing (SIP). The fermentation of (13) C-labeled glucose was monitored over 4 weeks by microcalorimetry in a stimulation experiment with tidal-flat sediments. Based on characteristic heat production phases, time points were selected for quantifying fermentation products and identifying substrate-assimilating bacteria by the isolation of intact ribosomes prior to rRNA-SIP. The preisolation of ribosomes resulted in rRNA with an excellent quality. Glucose was completely consumed within 2 days and was mainly fermented to acetate. Ethanol, formate, and hydrogen were detected intermittently. The amount of propionate that was built within the first 3 days stayed constant. Ribosome-based SIP of fully labeled and unlabeled rRNA was used for fingerprinting the glucose-degrading species and the inactive background community. The most abundant actively degrading bacterium was related to Psychromonas macrocephali (similarity 99%) as identified by DGGE and sequencing. The disappearance of Desulfovibrio-related bands in labeled rRNA after 3 days indicated that this group was active during the first degradation phase only. In summary, ribosome-based SIP in combination with microcalorimetry allows dissecting distinct phases in substrate turnover in a very sensitive manner.

  1. Cadmium and zinc relationships.

    Science.gov (United States)

    Elinder, C G; Piscator, M

    1978-08-01

    Cadmium and zinc concentrations in kidney and liver have been measured under different exposure situations in different species including man. The results show that zinc increases almost equimolarly with cadmium in kidney after long-term low-level exposure to cadmium, e.g., in man, horse, pig, and lamb. In contrast, the increase of zinc follows that of cadmium to only a limited extent, e.g., in guinea pig, rabbit, rat, mouse, and chicks. In liver, the cadmium--zinc relationship seems to be reversed in such a way that zinc increases with cadmium more markedly in laboratory animals than in higher mammals. These differences between cadmium and zinc relationships in humans and large farm animals and those in commonly used laboratory animals must be considered carefully before experimental data on cadmium and zinc relationships in laboratory animals can be extrapolated to humans.

  2. Field-based and laboratory stable isotope probing surveys of the identities of both aerobic and anaerobic benzene-metabolizing microorganisms in freshwater sediment

    Energy Technology Data Exchange (ETDEWEB)

    Liou, J.S.C.; DeRito, C.M.; Madsen, E.L. [Cornell University, Ithaca, NY (United States). Dept. of Microbiology

    2008-08-15

    Laboratory incubations of coal-tar waste-contaminated sediment microbial communities under relatively controlled physiological conditions were used to interpret results of a field-based stable isotope probing (SIP) assay. Biodegradation activity of {sub 13}C-benzene was examined by GC/MS determination of net (CO{sub 2})-{sub 13}C production and by GC headspace analysis of benzene loss. In anaerobic laboratory incubations of benzene at 10 p.p.m., greater than 60% of the substrate was eliminated within 15 days. During anaerobic incubations of 200 p.p.m. benzene (70 days), 0.9% benzene mineralization occurred. When benzene (36 p.p.m.) was added to sediment with air in the serum-bottle headspace, 14% of the initial C-13 was mineralized to (CO{sub 2})-{sub 13}C in 2.5 days. In the field experiment (178 {mu} g {sub 13}C-benzene dosed to undisturbed sediments), net (CO{sub 2})-{sub 13}C production reached 0.3% within 8.5 h. After isopycnic separation of {sub 13}C (heavy)-labelled DNA from the above biodegradation assays, sequencing of {sub 13}C-DNA clone libraries revealed a broad diversity of taxa involved in benzene metabolism and distinctive libraries for each biodegradation treatment. Perhaps most importantly, in the field SIP experiment the clone libraries produced were dominated by Pelomonas (betaproteobacteria) sequences similar to those found in the anaerobic 10 p.p.m. benzene laboratory experiment. These data indicate that the physiological conditions that prevail and govern in situ biodegradation of pollutants in the field may be interpreted by knowing the physiological preferences of potentially active populations.

  3. Field-based and laboratory stable isotope probing surveys of the identities of both aerobic and anaerobic benzene-metabolizing microorganisms in freshwater sediment.

    Science.gov (United States)

    Liou, J S-C; Derito, C M; Madsen, E L

    2008-08-01

    Laboratory incubations of coal-tar waste-contaminated sediment microbial communities under relatively controlled physiological conditions were used to interpret results of a field-based stable isotope probing (SIP) assay. Biodegradation activity of 13C-benzene was examined by GC/MS determination of net 13CO2 production and by GC headspace analysis of benzene loss. Key experimental variables were: the site of the assays (laboratory serum-bottle incubations and in situ field sediments), benzene concentration (10, 36 or 200 p.p.m. in laboratory assays), and physiological conditions (anaerobic with or without sulfate or nitrate additions versus aerobic headspace or the uncontrolled field). In anaerobic laboratory incubations of benzene at 10 p.p.m., greater than 60% of the substrate was eliminated within 15 days. During anaerobic incubations of 200 p.p.m. benzene (70 days), 0.9% benzene mineralization occurred. When benzene (36 p.p.m.) was added to sediment with air in the serum-bottle headspace, 14% of the initial 13C was mineralized to 13CO2 in 2.5 days. In the field experiment (178 microg 13C-benzene dosed to undisturbed sediments), net 13CO2 production reached 0.3% within 8.5 h. After isopycnic separation of 13C (heavy)-labelled DNA from the above biodegradation assays, sequencing of 13C-DNA clone libraries revealed a broad diversity of taxa involved in benzene metabolism and distinctive libraries for each biodegradation treatment. Perhaps most importantly, in the field SIP experiment the clone libraries produced were dominated by Pelomonas (betaproteobacteria) sequences similar to those found in the anaerobic 10 p.p.m. benzene laboratory experiment. These data indicate that the physiological conditions that prevail and govern in situ biodegradation of pollutants in the field may be interpreted by knowing the physiological preferences of potentially active populations.

  4. Cadmium and zinc relationships

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.; Piscator, M.

    1978-08-01

    Higher mammals, such as homo sapiens, accumulate zinc in kidney cortex almost equimolarly with cadmium. A different pattern seems to be present in liverthere is a limited increase of zinc in two species of large farm animals compared with a marked increase in the laboratory. In large farm animals, an equimolar increase of zinc with cadmium in renal cortex seems to indicate that the form of metallothionein that binds equal amounts of cadmium and zinc in present. Differences in cadmium and zinc relationships in large animals and humans compared with laboratory animals must be carefully considered. (4 graphs, 26 references)

  5. Application of {sup 13}C and {sup 15}N stable isotope probing to characterize RDX degrading microbial communities under different electron-accepting conditions

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Kun-Ching; Lee, Do Gyun [Zachry Department of Civil Engineering, Texas A& M University, College Station, TX 77843-3136 (United States); Fuller, Mark E.; Hatzinger, Paul B.; Condee, Charles W. [CB& I Federal Services, Lawrenceville, NJ (United States); Chu, Kung-Hui, E-mail: kchu@civil.tamu.edu [Zachry Department of Civil Engineering, Texas A& M University, College Station, TX 77843-3136 (United States)

    2015-10-30

    Highlights: • SIP characterized RDX-degrading communities under different e-accepting conditions. • Dominant RDX degradation pathways differed under different e-accepting conditions. • More complete detoxification of RDX occurred under methanogenic and sulfate-reducing conditions than under manganese(IV) and iron(III)-reducing conditions. - Abstract: This study identified microorganisms capable of using the explosive hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) or its metabolites as carbon and/or nitrogen sources under different electron-accepting conditions using {sup 13}C and {sup 15}N stable isotope probing (SIP). Mesocosms were constructed using groundwater and aquifer solids from an RDX-contaminated aquifer. The mesocosms received succinate as a carbon source and one of four electron acceptors (nitrate, manganese(IV), iron(III), or sulfate) or no additional electron acceptor (to stimulate methanogenesis). When RDX degradation was observed, subsamples from each mesocosm were removed and amended with {sup 13}C{sub 3}- or ring-{sup 15}N{sub 3}-, nitro-{sup 15}N{sub 3}-, or fully-labeled {sup 15}N{sub 6}-RDX, followed by additional incubation and isolation of labeled nucleic acids. A total of fifteen 16S rRNA sequences, clustering in α- and γ-Proteobacteria, Clostridia, and Actinobacteria, were detected in the {sup 13}C-DNA fractions. A total of twenty seven sequences were derived from different {sup 15}N-DNA fractions, with the sequences clustered in α- and γ-Proteobacteria, and Clostridia. Interestingly, sequences identified as Desulfosporosinus sp. (in the Clostridia) were not only observed to incorporate the labeled {sup 13}C or {sup 15}N from labeled RDX, but also were detected under each of the different electron-accepting conditions. The data suggest that {sup 13}C- and {sup 15}N-SIP can be used to characterize microbial communities involved in RDX biodegradation, and that the dominant pathway of RDX biodegradation may differ under different

  6. Characterization of Growing Soil Bacterial Communities across a pH gradient Using H218O DNA-Stable Isotope Probing

    Science.gov (United States)

    Welty-Bernard, A. T.; Schwartz, E.

    2014-12-01

    Recent studies have established consistent relationships between pH and bacterial diversity and community structure in soils from site-specific to landscape scales. However, these studies rely on DNA or PLFA extraction techniques from bulk soils that encompass metabolically active and inactive, or dormant, communities, and loose DNA. Dormant cells may comprise up to 80% of total live cells. If dormant cells dominate a particular environment, it is possible that previous interpretations of the soil variables assumed to drive communities could be profoundly affected. We used H218O stable isotope probing and bar-coded illumina sequencing of 16S rRNA genes to monitor the response of actively growing communities to changes in soil pH in a soil microcosm over 14 days. This substrate-independent approach has several advantages over 13C or 15N-labelled molecules in that all growing bacteria should be able to make use of water, allowing characterization of whole communities. We hypothesized that Acidobacteria would increasingly dominate the growing community and that Actinobacteria and Bacteroidetes would decline, given previously established responses by these taxa to soil pH. Instead, we observed the reverse. Actinobacteria abundance increased three-fold from 26 to 76% of the overall community as soil pH fell from pH 5.6 to pH 4.6. Shifts in community structure and decreases in diversity with declining soil pH were essentially driven by two families, Streptomyceaca and Microbacteracea, which collectively increased from 2 to 40% of the entire community. In contrast, Acidobacteria as a whole declined although numbers of subdivision 1 remained stable across all soil pH levels. We suggest that the brief incubation period in this SIP study selected for growth of acid-tolerant Actinobacteria over Acidobacteria. Taxa within Actinomycetales have been readily cultured over short time frames, suggesting rapid growth patterns. Conversely, taxa within Acidobacteria have been

  7. Structure of doubly-even cadmium nuclei studied by {beta}decay

    Energy Technology Data Exchange (ETDEWEB)

    Rinta-Antila, S.; Wang, Y.; Dendooven, P.; Huikari, J.; Kankainen, A.; Kolhinen, V.S.; Lhersonneau, G.; Nieminen, A.; Nummela, S.; Penttilae, H.; Peraejaervi, K.; Szerypo, J.; Wang, J.C. [University of Jyvaeskylae, Department of Physics, (YFL), Jyvaeskylae (Finland); Jokinen, A.; Aeystoe, J. [University of Jyvaeskylae, Department of Physics, (YFL), Jyvaeskylae (Finland); University of Helsinki, Helsinki Institute of Physics, Helsinki (Finland)

    2005-09-01

    We have studied the structure of even-even cadmium isotopes via beta decay of ground and excited isomeric states of parent silver isotopes. Measurements of mass A=116, 118 and 120 cadmium nuclides were carried out at an ion guide isotope separation on-line facility at the University of Jyvaeskylae. Decay schemes of {sup 116m}Ag, {sup 118m}Ag, {sup 120g}Ag and {sup 120m}Ag are considerably extended. Obtained data have enabled extension of available systematics of the three-phonon states to more neutron-rich cadmium nuclei. As a continuation we have conducted an experiment at ISOLDE, CERN to study heavier A=122, 124, and 126 cadmium nuclides, the analysis of the collected data is underway. (orig.)

  8. Zinc and cadmium monosalicylates

    Energy Technology Data Exchange (ETDEWEB)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K. (Moskovskij Khimiko-Tekhnologicheskij Inst. (USSR))

    1984-06-01

    Zinc and cadmium monosalicylates of the composition MSal, where M-Zn or Cd, Sal - twice deprotonated residue of salicylic acid O-HOC/sub 6/H/sub 4/COOH (H/sub 2/Sal), are singled out and characterized. When studying thermograms, thermogravigrams, IR absorption spectra, roentgenograms of cadmium salicylate compounds (Cd(OC/sub 6/H/sub 4/COO) and products of their thermal transformations, the processes of thermal decomposition of the compounds have been characterized. The process of cadmium monosalicylate decomposition takes place in one stage. Complete loss of salicylate acido group occurs in the range of 320-460 deg. At this decomposition stage cadmium oxide is formed. A supposition is made that cadmium complex has tetrahedral configuration, at that, each salicylate group plays the role of tetradentate-bridge ligand. The compound evidently has a polymer structure.

  9. Alternative materials to cadmium for neutron absorbers in safeguards applications

    Energy Technology Data Exchange (ETDEWEB)

    Freeman, Corey R [Los Alamos National Laboratory; Geist, William H [Los Alamos National Laboratory; West, James D [Los Alamos National Laboratory

    2009-01-01

    Cadmium is increasingly difficult to use in safeguards applications because of rising cost and increased safety regulations. This work examines the properties of two materials produced by Ceradyne, inc. that present alternatives to cadmium for neutron shielding. The first is an aluminum metal doped with boron and the second is a boron carbide powder, compressed into a ceramic. Both are enriched in the {sup 10}B isotope. Two sheets of boron doped aluminum (1.1 mm and 5.2mm thick) and one sheet of boron carbide (8.5mm thick) were provided by Ceradyne for testing. An experiment was designed to test the neutron absorption capabilities of these three sheets against two different thicknesses of cadmium (0.6mm and 1.6mm thick). The thinner piece of aluminum boron alloy (1.1mm) performed as well as the cadmium pieces at absorbing neutrons. The thicker aluminum-boron plate provided more shielding than the cadmium sheets and the boron carbide performed best by a relatively large margin. Monte Carlo N-Particle eXtended (MCNPX) transport code modeling of the experiment was performed to provide validaLed computational tools for predicting the behavior of systems in which these materials may be incorporated as alternatives to cadmium. MCNPX calculations predict that approximately 0.17mm of the boron carbide is equivalent to 0.6mm of cadmium. There are drawbacks to these materials that need to be noted when considering using them as replacements for cadmium. Notably, they may need to be thicker than cadmium, and are not malleable, requiring machining to fit any curved forms.

  10. Screening of Amaranth Cultivars (Amaranthus mangostanus L.) for Cadmium Hyperaccumulation

    Institute of Scientific and Technical Information of China (English)

    FAN Hong-li; ZHOU Wei

    2009-01-01

    The potential harm of soil cadmium pollution to ecological environment and human health has been increasingly widely concerned. Phytoremediation, as a kind of new and effective technology, has become an important method for cleaning up cadmium in contaminated sites. The amaranth (Amaranthus mangostanus L.) is widely distributed and has abundant varieties in China, its rapid growth and large biomass can be served as candidate for cadmium hyperaccumulators for phytoremediation. To obtain cadmium hyper-accumulator, Cd uptake in 23 amaranth euitivars from different ecological region was investigated under hydroponic culture condition. Meanwhile, pot experiment was established to probe phytoremediation potentiality of Cd contaminated soil by amaranth. Three treatment (Cd 5, 10, and 25 mg kg-1) were imposed to red soil, yellow brown soil, and vegetable soil. The results showed that under hydroponic culture with Cd 3 mg L-1, the cadmium concentration in the shoots of the cultivar Tianxingmi reached 260 mg kg-1, and its total cadmium uptake was the highest among various cultivars. In the treatment Cd 25 mg kg-1, the cadmium concentration in the shoots of the cultivar Tianxingmi reached 212 mg kg-1, while bioaccumulation factor and shoot purification rate reached 8.50 and 3.8%, respectively. Further, the total biomass and shoot biomass were not decreased significantly under Cd exposure.These results suggested that eultivar Tianxingmi is a typical Cd hyperaccumulator, and can be expected to be used in phytoremediation of Cd contaminated soil.

  11. Cadmium status in Egypt

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is inferred from these studies that releases of Cd are still increasing and it is recommended that measures must be taken to reduce emissions of cadmium. Any cadmium discharged into the Egyptian environment may move from one compartment to another at varying rates,resulting in an accumulation in compartments such as soils and biota. Such accumulation can be expected to increase with continued emissions,and attention should be given to all sources of cadmium, natural as well as anthropogenic especially in the industrial cities in Egypt. Cadmium present in sewage, as well as industrial effluent (also, other liquid and solid wastes) and sewage sludge will increase levels in soils and is xpected to contribute to dietary levels and body burdens. The current information indicates that such effects may have to be evaluated over long periods of time, possibly as long as 50 - 100 years.

  12. Effects of Soil pH,Texture,Moisture,Organic Matter and Cadmium Content on Cadmium Diffusion Coefficient

    Institute of Scientific and Technical Information of China (English)

    WUQI-TANG; J.L.MOREL; 等

    1994-01-01

    The supply of cadmium from soil to plant roots mainly depends on the diffusion prooess.This work was conducted to study the effects of some soil properties on cadmium diffusion coefficient (D) in soil. Measurements were made using the Shofield and Graham-Bryce's isotopic labelling method.Cadmium diffusion coefficients varied from 10-7to 10-9 cms2-1.Higher values were observed in acid sandy soils and lower values in calcareous clay soils.Liming an acid soil resulted in a substantial decrease of D.Addition of cadmium as nitrate salt generally increased D,while addition of sewage sludge and organic matter resulted in a significant decrease of cadmium diffusion.The rhizospheric activity also induced a moderate reduction in D.The relationships between D(10-9cms2-1)on the on hand and soil pH.moisture(Mc,g kg-1) ,organic matter(OM,g kg-1),clay(Cy,gkg-1)and cadmium content(Cd,mgkg-1) on the other were obtained by the multiple regression:D=182.1-29.91pH+0.210Mc-0.303OM+0.011Cy+1.64Cd(R2=0.859,n=22).

  13. Plausible Mechanisms of Cadmium Carcinogenesis

    Science.gov (United States)

    Cadmium is a transition metal and an ubiquitous environmental and industrial pollutant. Laboratory animal studies and epidemiological studies have shown that exposure to cadmium is associated with various organ toxicities and carcinogenic effects. Several national and internation...

  14. Cadmium and zinc in pregnancy and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Lucis, O.J.; Lucis, R.; Shaikh, Z.A.

    1972-07-01

    Radioactive cadmium (/sup 109/Cd) and zinc (/sup 65/Zn) were injected subcutaneously into pregnant rats. More cadmium than zinc was found in the placentae. After birth, newborns showed detectable /sup 109/Cd only in liver, gastrointestinal tract, and in the brain tissue. Zinc 65 was present in all newborns' tissues. During lactation, highest output of /sup 65/Zn was in colostrum and, on subsequent days, /sup 65/Zn in milk declined rapidly. Cadmium 109 in milk was present in low concentration throughout the lactation period. Rats injected with /sup 109/Cd and /sup 65/Zn after parturition excreted these isotopes in milk in a similiar pattern. Newborns nursed on radioactive milk showed rapid absorption of /sup 65/Zn, whereas /sup 109/Cd accumulated primarily in the intestinal tract; a lesser quantity of /sup 109/Cd was deposited in the liver. In other organs, only /sup 65/Zn was found. The lactating mammary gland contained more /sup 109/Cd than /sup 65/Zn; after lactation, /sup 65/Zn was depleted, whereas /sup 109/Cd remained in mammary tissue.

  15. Preparation and Characterization of Fluorescence Probe from Assembly Hydroxyapatite Nanocomposite

    Directory of Open Access Journals (Sweden)

    Li Guang-Ming

    2010-01-01

    Full Text Available Abstract A new nanocomposite fluorescence probe with thioglycolic acid (TA functional layers embedded inside the hydroxyapatite nanoribbon spherulites has been synthesized. The fluorescence intensity of the novel probe is about 1.5–3.3-fold increase compared with the probe containing no TA. When used to detect cadmium ion, the most of original assembly nanoribbon spherulites structure in the novel probe is found to have been damaged to new flake structures. The mechanism of determining cadmium ion in alcohol solution has been studied. The present systematic study provides significant information on the effect of assembly nanostructure on the metal-enhanced fluorescence phenomenon.

  16. 29 CFR 1910.1027 - Cadmium.

    Science.gov (United States)

    2010-07-01

    ... battery Plate making, plate preparation 50 All other processes 15 Zinc/Cadmium refining* Cadmium refining... as an airborne concentration of cadmium of 2.5 micrograms per cubic meter of air (2.5 µg/m3... air cadmium level to which an employee is exposed means the exposure to airborne cadmium that...

  17. Penning-trap mass spectrometry of neutron-rich copper isotopes for probing the Z = 28 and N = 50 shell closures

    CERN Multimedia

    Manea, V

    We propose to perform a Penning-trap mass measurement of $^{79}$Cu. This exotic N = 50 isotone is the last frontier before the doubly-magic $^{78}$Ni and will greatly improve our knowledge of shell evolution. In the same run, we propose $^{77-78}$Cu mass measurements, as well as the search for a possible isomer in $^{76m}$Cu. The data will help to clarify the structure of the odd proton in the Cu isotopes, the influence on the Z = 28 proton core of the νg$_{9/2}$ orbital filling and the impact of the proton-neutron residual interaction on the strength of the N = 50 shell closure.

  18. Nuclear spins, magnetic moments and quadrupole moments of Cu isotopes from N = 28 to N = 46: probes for core polarization effects

    CERN Document Server

    Vingerhoets, P; Avgoulea, M; Billowes, J; Bissell, M L; Blaum, K; Brown, B A; Cheal, B; De Rydt, M; Forest, D H; Geppert, Ch; Honma, M; Kowalska, M; Kramer, J; Krieger, A; Mane, E; Neugart, R; Neyens, G; Nortershauser, W; Otsuka, T; Schug, M; Stroke, H H; Tungate, G; Yordanov, D T

    2010-01-01

    Measurements of the ground-state nuclear spins, magnetic and quadrupole moments of the copper isotopes from 61Cu up to 75Cu are reported. The experiments were performed at the ISOLDE facility, using the technique of collinear laser spectroscopy. The trend in the magnetic moments between the N=28 and N=50 shell closures is reasonably reproduced by large-scale shell-model calculations starting from a 56Ni core. The quadrupole moments reveal a strong polarization of the underlying Ni core when the neutron shell is opened, which is however strongly reduced at N=40 due to the parity change between the $pf$ and $g$ orbits. No enhanced core polarization is seen beyond N=40. Deviations between measured and calculated moments are attributed to the softness of the 56Ni core and weakening of the Z=28 and N=28 shell gaps.

  19. Cadmium - is it hazardous

    Energy Technology Data Exchange (ETDEWEB)

    Zartner-Nyilas, G.; Valentin, H.; Schaller, K.H.; Schiele, R.

    1983-01-01

    The report summarizes the state of knowledge and experience on cadmium. Biological, toxicological and epidemiological data have been evaluated. Cd pollution of the environment is reviewed under the aspect of human health. Uptake in food, threshod values of Cd exposure of the population, types and extent of health hazards, possible carcinogenic effects and future fields of research are discussed.

  20. Cadmium and cancer.

    Science.gov (United States)

    Hartwig, Andrea

    2013-01-01

    Cadmium is an established human and animal carcinogen. Most evidence is available for elevated risk for lung cancer after occupational exposure; however, associations between cadmium exposure and tumors at other locations including kidney, breast, and prostate may be relevant as well. Furthermore, enhanced cancer risk may not be restricted to comparatively high occupational exposure, but may also occur via environmental exposure, for example in areas in close proximity to zinc smelters. The underlying mechanisms are still a matter of manifold research activities. While direct interactions with DNA appear to be of minor importance, elevated levels of reactive oxygen species (ROS) have been detected in diverse experimental systems, presumably due to an inactivation of detoxifying enzymes. Also, the interference with proteins involved in the cellular response to DNA damage, the deregulation of cell growth as well as resistance to apoptosis appears to be involved in cadmium-induced carcinogenicity. Within this context, cadmium has been shown to disturb nucleotide excision repair, base excision repair, and mismatch repair. Particularly sensitive targets appear to be proteins with zinc-binding structures, present in DNA repair proteins such as XPA, PARP-1 as well as in the tumor suppressor protein p53. Whether or not these interactions are due to displacement of zinc or due to reactions with thiol groups involved in zinc complexation or in other critical positions under realistic exposure conditions remains to be elucidated. Further potential mechanisms relate to the interference with cellular redox regulation, either by enhanced generation of ROS or by reaction with thiol groups involved in the regulation of signaling pathways. Particularly the combination of these multiple mechanisms may give rise to a high degree of genomic instability evident in cadmium-adapted cells, relevant not only for tumor initiation, but also for later steps in tumor development.

  1. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    2013-01-01

    Mobile probing is a method, developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time and space......). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings point...... to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face). The development...

  2. Mobile Probing and Probes

    DEFF Research Database (Denmark)

    2012-01-01

    Mobile probing is a method, which has been developed for learning about digital work situations, as an approach to discover new grounds. The method can be used when there is a need to know more about users and their work with certain tasks, but where users at the same time are distributed (in time...... and space). Mobile probing was inspired by the cultural probe method, and was influenced by qualitative interview and inquiry approaches. The method has been used in two subsequent projects, involving school children (young adults at 15-17 years old) and employees (adults) in a consultancy company. Findings...... point to mobile probing being a flexible method for uncovering the unknowns, as a way of getting rich data to the analysis and design phases. On the other hand it is difficult to engage users to give in depth explanations, which seem easier in synchronous dialogs (whether online or face2face...

  3. DNA稳定同位素探针技术在宏基因组学中的应用及前景%Applications and perspectives of DNA stable-isotope probing in metagenomics: a review

    Institute of Scientific and Technical Information of China (English)

    刘威; 魏晓; 袁静; 黄留玉

    2011-01-01

    DNA stable-isotope probing (DNA-SIP) is a recently developed method with which the incorporation of stable isotope from a labeled substrate is used to identify the function of microorganisms in the environment. The technique has now been used in conjunction with metagenomics to establish links between microbial identity and particular metabolic functions. The combination of DNA-SIP and metagenomics not only permits the detection of rare low-abundance species from metagenomic libraries but also facilitates the detection of novel enzymes and bioactive compounds. We summarize recent progress in SIP-metagenomic techniques and applications and discuss prospects for this combined approach in environmental microbiology and biotechnology.%DNA稳定同位素探针(DNA-SIP)是一种新兴的技术,通过将同位素稳定结合到特定的底物来确定环境中微生物的作用.DNA-SIP与宏基因组学结合可以让某些微生物的特性与其特殊新陈代谢联系在一起,不仅可以从宏基因组库里检测到低含量的微生物,而且加速了对新的酶类和其他生物活性物质的发现.以下总结了SIP-宏基因组学技术的原理、应用及研究进展,并讨论了其在环境微生物学和生物技术的应用前景.

  4. Cadmium in Sweden - environmental risks

    Energy Technology Data Exchange (ETDEWEB)

    Parkman, H.; Iverfeldt, Aa. [Swedish Environmental Research Inst. (Sweden); Borg, H.; Lithner, G. [Stockholm Univ. (Sweden). Inst. for Applied Environmental Research

    1998-03-01

    This report aims at assessing possible effects of cadmium in the Swedish environment. Swedish soils and soft freshwater systems are, due to a generally poor buffering capacity, severely affected by acidification. In addition, the low salinity in the Baltic Sea imply a naturally poor organism structure, with some important organisms living close to their limit of physiological tolerance. Cadmium in soils is mobilized at low pH, and the availability and toxicity of cadmium in marine systems are enhanced at low salinity. The Swedish environment is therefore extra vulnerable to cadmium pollution. The average concentrations of cadmium in the forest mor layers, agricultural soils, and fresh-waters in Sweden are enhanced compared to `back-ground concentrations`, with a general increasing trend from the north to the south-west, indicating strong impact of atmospheric deposition of cadmium originating from the central parts of Europe. In Swedish sea water, total cadmium concentrations, and the fraction of bio-available `free` cadmium, generally increases with decreasing salinity. Decreased emissions of cadmium to the environment have led to decreasing atmospheric deposition during the last decade. The net accumulation of cadmium in the forest mor layer has stopped, and even started to decrease. In northern Sweden, this is due to the decreased deposition, but in southern Sweden the main reason is increased leakage of cadmium from the topsoil as a consequence of acidification. As a result, cadmium in the Swedish environments is undergoing an extended redistribution between different soil compartments, and from the soils to the aquatic systems. 90 refs, 23 figs, 2 tabs. With 3 page summary in Swedish

  5. Renal cadmium overload without nephrotoxicity.

    OpenAIRE

    1981-01-01

    A redundant nickel/cadmium battery worker was investigated for non-specific fatigue after completing five years in the industry. Sensitive techniques for in-vivo organ cadmium measurement showed a moderate accumulation in the liver but a very large concentration in the kidneys. Despite this, overall glomerular and tubular function were not impaired. It was concluded that the mechanism of proteinuria observed in some cadmium workers is obscure and not clearly related to the degree of kidney sa...

  6. Production rate estimation of mycosporine-like amino acids in two Arctic melt ponds by stable isotope probing with NAH(13) CO3.

    Science.gov (United States)

    Ha, Sun-Yong; Min, Jun-Oh; Joo, Hyun Min; Chung, Kyung Ho; Shin, Kyung-Hoon; Yang, EunJin; Kang, Sung-Ho

    2014-10-01

    The net carbon uptake rate and net production rate of mycosporine-like amino acids (MAAs) were measured in phytoplankton from 2 different melt ponds (MPs; closed and open type pond) in the western Arctic Ocean using a (13) C stable isotope tracer technique. The Research Vessel Araon visited ice-covered western-central basins situated at 82°N and 173°E in the summer of 2012, when Arctic sea ice declined to a record minimum. The average net carbon uptake rate of the phytoplankton in polycarbonate (PC) bottles in the closed MP was 3.24 mg C · m(-3) · h(-1) (SD = ±1.12 mg C · m(-3) · h(-1) ), while that in the open MP was 1.3 mg C · m(-3) · h(-1) (SD = ±0.05 mg C · m(-3) · h(-1) ). The net production rate of total MAAs in incubated PC bottles was highest (1.44 (SD = ±0.24) ng C · L(-1) · h(-1) ) in the open MP and lowest (0.05 (SD = ±0.003) ng C · L(-1) · h(-1) ) in the closed MP. The net production rate of shinorine and palythine in incubated PC bottles at the open MP presented significantly high values 0.76 (SD = ±0.12) ng C · L(-1) · h(-1) and 0.53 (SD = ±0.06) ng C · L(-1) · h(-1) . Our results showed that high net production rate of MAAs in the open MP was enhanced by a combination of osmotic and UVR stress and that in situ net production rates of individual MAA can be determined using (13) C tracer in MPs in Arctic sea ice.

  7. CADMIUM – ENVIRONMENTAL HAZARD

    Directory of Open Access Journals (Sweden)

    Henryka Langauer-Lewowicka

    2010-06-01

    Full Text Available The paper presents some information about current status of cadmium as an environmental health problem. Agricultural uses of phosphate fertilizers, sewage sludge and industrial uses of Cd are the major source of widespread of this metal at trace levels into the general environment and human foodstuffs. It is well known that high cadmium (Cd exposure causes renal damage, anemia, enteropathy, osteoporosis, osteomalacia, whereas the dose-response relationship at low levels exposure is less established. During the last decade an increasing number of studies have found an adverse health effects due to low environmental exposure to Cd. Many authors try to determine the relationship between Cd intake and Cd toxicity indicators, especially dealing renal tubular damage. The level of b2-microglobulin in urine is regarded as the most sensitive biomarker of renal disfunction due to low environmental Cd concentrations.

  8. Speciation of Dissolved Cadmium

    DEFF Research Database (Denmark)

    Holm, Peter Engelund; Andersen, Sjur; Christensen, Thomas Højlund

    1995-01-01

    Equilibrium dialysis and ion exchange methods, as well as computer calculations (GEOCHEM), were applied for speciation of dissolved cadmium (Cd) in test solutions and leachate samples. The leachate samples originated from soil, compost, landfill waste and industrial waste. The ion exchange (IE...... leachates showed different Cd speciation patterns as expected. Some leachates were dominated by free divalent Cd (1-70%), some by inorganic complexes (1-87%), and some by organic complexes (7-98%)....

  9. Is cadmium hazardous to health. Cadmium - ein Gesundheitsrisiko

    Energy Technology Data Exchange (ETDEWEB)

    Zartner-Nyilas, G.; Valentin, H.; Schaller, K.H.; Schiele, R.

    1983-01-01

    This study entitled ''Is cadmium hazardous to health'' summarizes the current state of knowledge on and experience with cadmium. The authors have made efforts to take into account the more recent literature relating to cadmium. The data evaluated were, especially, biological, toxicological, and epidemiological ones. A principal object was to try to assess the importance of the presence of cadmium in the environment to man. The interest was focused on the uptake of heavy metals with food, danger thresholds for the cadmium exposure of the population, nature and extent of eventual damage to health including possible carcinogenous effects, and suggestions for further points of main emphasis in research. 3 figs., 12 tabs.

  10. Cadmium exposure in the Swedish environment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-03-01

    This report gives a thorough description of cadmium in the Swedish environment. It comprises three parts: Cadmium in Sweden - environmental risks;, Cadmium in goods - contribution to environmental exposure;, and Cadmium in fertilizers, soil, crops and foods - the Swedish situation. Separate abstracts have been prepared for all three parts

  11. Cadmium carcinogenesis – some key points

    OpenAIRE

    2011-01-01

    The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney) induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  12. Cadmium carcinogenesis – some key points

    Directory of Open Access Journals (Sweden)

    Loreta Strumylaite

    2011-09-01

    Full Text Available The article presents briefly the main mechanisms of cadmium carcinogenesis and the most important sites of cancer (lung, breast, prostate, testes, kidney induced by cadmium. In spite of some evidence showing carcinogenic potential of cadmium, further research is still required to elucidate the relative contributions of various molecular mechanisms involved in cadmium carcinogenesis

  13. 土壤样品镉同位素分析中Cd与Sn有效分离方法的改进%Improvement on EffeCtive Separation between Cadmium and Tin in Soil Samples for the Determination of Cadmium IsotopiC Composition

    Institute of Scientific and Technical Information of China (English)

    段桂玲; 段瑞春; 谭娟娟; 顾涛; 邵长生; 路韬

    2016-01-01

    保证 Cd 的高回收率以及彻底的 Sn 干扰去除是获得精确镉同位素组成的前提,目前报道的多种 Cd 分离与纯化方法获得的 Cd回收率有较大差异(42. 6% ~ 99. 8% ),且去除 Sn 干扰的效果也不同(去除率在 87. 8% ~ 97. 4% 之间),Cd 回收率和 Sn 去除率均不理想.本文对前人报道的分离方法进行对比实验,发现 0. 1 mol/ L氢溴酸 - 0. 5 mol/ L 硝酸是分离 Cd 和 Sn 的有效试剂,增加该组混合酸的用量可淋洗出样品中更多的 Sn 且不会损失 Cd,当混合酸的淋洗用量增加至 30 mL 时,Sn 的淋洗率达到99. 8% 以上,Cd 的回收率亦达到 99. 0% ± 0. 5% ,可满足土壤样品镉同位素的测定要求.本工作为获得高精度的镉同位素组成奠定了基础,为研究土壤环境中镉的污染来源提供了技术手段.%In order to determine Cd isotopic composition accurately,the key is to guarantee Cd recovery and reduce Sn interference. The recoveries of Cd with various separation and purification methods reported by previous studies show a large range variation from 42. 6% to 99. 8% ,and the removal efficiency of Sn interference are various (87. 8% - 97. 4% ). Both the Cd recovery and Sn removal are not ideal. Reported in this study,0. 1 mol/ L HBr-0. 5 mol/ L HNO3 mixture was determined to be a more effective solution to separate Cd from Sn. By increasing the amount of this mixture during leaching,more Sn can be removed from the samples without Cd loss. When 30 mL of mixture is used during leaching,more than 99. 8% Sn can be leached out from the sample and the Cd recovery is 99. 0% ± 0. 5% . This method can be utilized for Cd isotope analyses of soil samples,offering new insight for high-precision Cd isotope measurement and serving as a technical method for Cd pollution tracing in the study of environmental soil.

  14. Cadmium immobilization by hydroxyapatite

    Directory of Open Access Journals (Sweden)

    Smičiklas Ivana D.

    2003-01-01

    Full Text Available The contamination of air, soil and water by cadmium is a great environmental problem. If cadmium occurs in nature in ionic form, soluble in water, it easily enters into the food chain. Hydroxyapatite (HAP, Ca-o(POAe(OH2 is a sparingly soluble salt and an excellent matrix for the removal of heavy metals from solutions. Considerable research attention has been paid to the bond between Cc/2+ ions and synthetic hydroxyapatite of known composition. The sorption mechanism is complex. The dominant process is ion exchange, but surface adsorption, surface complexation and coprecipitation can also contribute to the overall mechanism. The sorption capacity depends on the characteristics of hydroxyapatite itself and on the experimental conditions. Under optimum conditions a maximum capacity of 0.8 mol Cd2+/mol HAP can be achieved. HAP is a potential sorbent for the remediation of contaminated water and soil, for industrial waste treatment, and it is also referenced as a material that can be used as a barrier around waste depositories.

  15. Cadmium effects on the thyroid gland.

    Science.gov (United States)

    Jancic, Snezana A; Stosic, Bojan Z

    2014-01-01

    Cadmium has been listed as one of the 126 priority pollutants and a category I carcinogen. Carcinogenic effects of cadmium on the lungs, testicles, and prostate are widely recognized, but there has been insufficient research on the effect of cadmium on the thyroid gland. Cadmium has the affinity to accumulate not only in the liver, kidneys, and pancreas but also in the thyroid gland. It has been established that cadmium blood concentration correlates positively with its accumulation in the thyroid gland. Women of fertile age have higher cadmium blood and urine concentrations than men. In spite of its redox inertia, cadmium brings about oxidative stress and damage to the tissue by indirect mechanisms. Mitochondria are considered to be the main intracellular targets for cadmium. Colloid cystic goiter, adenomatoid follicular hyperplasia with low-grade dysplasia and thyroglobulin hypo- and asecretion, and parafollicular cell diffuse and nodular hyperplasia and hypertrophy are often found in chronic cadmium toxicity.

  16. Enrichment of cadmium in biomasses

    Energy Technology Data Exchange (ETDEWEB)

    Gwenner, C.; Wittig, H.; Glombitza, F.

    1986-01-01

    The uptake of cadmium ions from an aqueous solution by living, resting, and dead biomasses was investigated. The dependence of the uptaked amounts on pH-value of the medium, temperature and concentration of cadmium ions is demonstrated as well as the rate of uptake. Maximum realisable concentrations were 12 mg/g biomass in living cells and about 20 mg/g biomass in resting or dead cells, respectively.

  17. Nuclear probes and intraoperative gamma cameras.

    Science.gov (United States)

    Heller, Sherman; Zanzonico, Pat

    2011-05-01

    Gamma probes are now an important, well-established technology in the management of cancer, particularly in the detection of sentinel lymph nodes. Intraoperative sentinel lymph node as well as tumor detection may be improved under some circumstances by the use of beta (negatron or positron), rather than gamma detection, because the very short range (∼ 1 mm or less) of such particulate radiations eliminates the contribution of confounding counts from activity other than in the immediate vicinity of the detector. This has led to the development of intraoperative beta probes. Gamma camera imaging also benefits from short source-to-detector distances and minimal overlying tissue, and intraoperative small field-of-view gamma cameras have therefore been developed as well. Radiation detectors for intraoperative probes can generally be characterized as either scintillation or ionization detectors. Scintillators used in scintillation-detector probes include thallium-doped sodium iodide, thallium- and sodium-doped cesium iodide, and cerium-doped lutecium orthooxysilicate. Alternatives to inorganic scintillators are plastic scintillators, solutions of organic scintillation compounds dissolved in an organic solvent that is subsequently polymerized to form a solid. Their combined high counting efficiency for beta particles and low counting efficiency for 511-keV annihilation γ-rays make plastic scintillators well-suited as intraoperative beta probes in general and positron probes in particular Semiconductors used in ionization-detector probes include cadmium telluride, cadmium zinc telluride, and mercuric iodide. Clinical studies directly comparing scintillation and semiconductor intraoperative probes have not provided a clear choice between scintillation and ionization detector-based probes. The earliest small field-of-view intraoperative gamma camera systems were hand-held devices having fields of view of only 1.5-2.5 cm in diameter that used conventional thallium

  18. Zinc-induced protection against cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Early, J.L.; Schnell, R.C.

    1978-02-01

    Pretreatment of male rats with cadmium acetate potentiates the duration of hexobarbital hypnosis and inhibits the rate of hepatic microsomal drug metabolism. Pretreatment of rats with zinc acetate protects against these alterations in drug action elicited by cadmium.

  19. Metallothionein and bioaccumulation of cadmium in juvenile bluegills exposed to aqueous and sediment-associated cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Cope, W.G.

    1991-01-01

    The author evaluated metallothionein (MT), free (unbound) hepatic cadmium and whole body cadmium as indicators of cadmium exposure in juvenile bluegills Lepomis macrochirus in laboratory tests. Two types of cadmium exposure were tested; aqueous and sediment-associated. In the aqueous tests, fish were exposed to cadmium (0.0 to 32.3 [mu]g/L) in an intermittent-flow diluter. In the sediment-associated cadmium test, fish were exposed to resuspended river sidment containing 1.3 to 21.4 [mu]g Cd/g (dry weight) at a nominal total suspended solids concentration of 1,000 mg/L in revolving, circular glass exposure chambers. Total cadmium concentrations were measured in various bluegill liver fractions, whole bluegill, water, and resuspended sediment to assess the partitioning and bioaccumulation of cadmium after the tests. Mean concentrations of MT and free cadmium in bluegill livers and concentrations of cadmium in whole bluegills were positively correlated with aqueous cadmium concentration and were equally suitable as indicators of aqueous cadmium exposure. Sediment-associated cadmium was biologically available, but to a lesser extent than aqueous cadmium. Cadmium concentrations in whole bluegills exposed to resuspended river sediment were 1.5- to 3.5-fold the concentrations in bluegills in sediment-free controls. Free cadmium and MT concentrations in bluegill liver and whole-body cadmium concentrations in bluegills were positively correlated with the cadmium concentrations in filtered water, resuspended sediment, and bulk river sediment; however, whole-body cadmim concentrations were a more sensitive indicator of exposure to sediment-associated cadmium than either free cadmium or MT concentratons in liver.

  20. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Sloth, Jens Jørgen; Rasmussen, Rie Romme

    In Denmark and EU the exposure of cadmium from food is at a level that is relatively close to the Tolerable Daily Intake (TDI). This report describes an investigation of the bioavailability of cadmium in selected food items known to contain high levels of cadmium. The purpose was to provide data ...... or crushed linseed nor the intake of cocoa and chocolate....

  1. Leatherback Isotopes

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — SWFSC is currently working on a project identifying global marine isotopes using leatherback turtles (Dermochelys coriacea) as the indicator species. We currently...

  2. Isotopic Paleoclimatology

    Science.gov (United States)

    Bowen, R.

    Paleotemperature scales were calculated by H. C. Urey and others in the 1950s to assess past temperatures, and later work using the stable isotopes of oxygen, hydrogen, and carbon employed standards such as Peedee belemnite (PDB) and Standard Mean Ocean Water (SMOW). Subsequently, subjects as diverse as ice volume and paleotemperatures, oceanic ice and sediment cores, Pleistocene/Holocene climatic changes, and isotope chronostratigraphy extending back to the Precambrian were investigated.

  3. Probe Storage

    NARCIS (Netherlands)

    Gemelli, Marcellino; Abelmann, Leon; Engelen, Johan B.C.; Khatib, Mohammed G.; Koelmans, Wabe W.; Zaboronski, Olog; Campardo, Giovanni; Tiziani, Federico; Laculo, Massimo

    2011-01-01

    This chapter gives an overview of probe-based data storage research over the last three decades, encompassing all aspects of a probe recording system. Following the division found in all mechanically addressed storage systems, the different subsystems (media, read/write heads, positioning, data chan

  4. Cultural probes

    DEFF Research Database (Denmark)

    Madsen, Jacob Østergaard

    2016-01-01

    The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation.......The aim of this study was thus to explore cultural probes (Gaver, Boucher et al. 2004), as a possible methodical approach, supporting knowledge production on situated and contextual aspects of occupation....

  5. Oral cadmium chloride intoxication in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B; Svendsen, P

    1988-01-01

    Diethyldithiocarbamate (DDC) is known to alleviate acute toxicity due to injection of cadmium salts. However, when cadmium chloride was administered by the oral route, DDC enhanced rather than alleviated the acute toxicity; both oral and intraperitoneal (i.p.) administration of DDC had this effect....... Thus, orally administered DDC enhanced cadmium-induced duodenal and ileal tissue damage and inhibition of peristalsis, as indicated by an increased intestinal transit time. At low cadmium doses, the whole-body retention of cadmium was increased by oral DDC administration. Intraperitoneally administered...

  6. Arsenic-cadmium interaction in rats.

    Science.gov (United States)

    Díaz-Barriga, F; Llamas, E; Mejía, J J; Carrizales, L; Santoyo, M E; Vega-Vega, L; Yáñez, L

    1990-11-01

    Simultaneous exposure to cadmium and arsenic is highly probable in the urban area of San Luis Potosi, Mexico due to common localization of copper and zinc smelters. Therefore, in this work, rats were intraperitoneally exposed either to cadmium or arsenic alone, or simultaneously to both metals. The effects of these treatments on three different toxicological parameters were studied. Cadmium modified the LD50 of arsenic and conversely arsenic modified the LD50 for cadmium. At the histopathological level, arsenic appeared to protect against the cadmium effects, especially on testes. This protective effect seemed to be related to the glutathione levels found in this tissue: rats exposed to both arsenic and cadmium, presented glutathione values intermediate to those observed after exposure to either metal alone; arsenic had the highest value and cadmium the lowest. In liver, rats exposed to arsenic, cadmium or arsenic and cadmium, presented glutathione values below those in the saline group, with the lowest value corresponding to the arsenic and cadmium treatment. The results appear to support the proposed interaction between arsenic and cadmium and coexposure to both metals seems to alter certain effects produced by either metal alone.

  7. Variation in electrical properties of gamma irradiated cadmium selenate nanowires

    Energy Technology Data Exchange (ETDEWEB)

    Chauhan, R.P., E-mail: chauhanrpc@gmail.com; Rana, Pallavi, E-mail: prana.phy@gmail.com; Narula, Chetna; Panchal, Suresh; Choudhary, Ritika

    2016-07-15

    Preparation of low-dimensional materials attracts more and more interest in the last few years, mainly due to the wide field of potential commercial applications ranging from life sciences, medicine and biotechnology to communication and electronics. One-dimensional systems are the smallest dimension structures that can be used for efficient transport of electrons and thus expected to be critical to the function and integration of nanoscale devices. Nanowires with well controlled morphology and extremely high aspect ratio can be obtained by replicating a nanoporous polymer ion-track membrane with cylindrical pores of controlled dimensions. With this technique, materials can be deposited within the pores of the membrane by electrochemical reduction of the desired ion. In the present study, cadmium selenate nanowires were synthesized potentiostatically via template method. These synthesized nanowires were then exposed to gamma rays by using a {sup 60}Co source at the Inter University Accelerator Centre, New Delhi, India. Structural, morphological, electrical and elemental characterizations were made in order to analyze the effect of gamma irradiation on the synthesized nanowires. I–V measurements of cadmium selenate nanowires, before and after irradiation were made with the help of Keithley 2400 source meter and Ecopia probe station. A significant change in the electrical conductivity of cadmium selenate nanowires was found after gamma irradiation. The crystallography of the synthesized nanowires was also studied using a Rigaku X-ray diffractrometer equipped with Cu-Kα radiation. XRD patterns of irradiated samples showed no variation in the peak positions or phase change.

  8. Variation in electrical properties of gamma irradiated cadmium selenate nanowires

    Science.gov (United States)

    Chauhan, R. P.; Rana, Pallavi; Narula, Chetna; Panchal, Suresh; Choudhary, Ritika

    2016-07-01

    Preparation of low-dimensional materials attracts more and more interest in the last few years, mainly due to the wide field of potential commercial applications ranging from life sciences, medicine and biotechnology to communication and electronics. One-dimensional systems are the smallest dimension structures that can be used for efficient transport of electrons and thus expected to be critical to the function and integration of nanoscale devices. Nanowires with well controlled morphology and extremely high aspect ratio can be obtained by replicating a nanoporous polymer ion-track membrane with cylindrical pores of controlled dimensions. With this technique, materials can be deposited within the pores of the membrane by electrochemical reduction of the desired ion. In the present study, cadmium selenate nanowires were synthesized potentiostatically via template method. These synthesized nanowires were then exposed to gamma rays by using a 60Co source at the Inter University Accelerator Centre, New Delhi, India. Structural, morphological, electrical and elemental characterizations were made in order to analyze the effect of gamma irradiation on the synthesized nanowires. I-V measurements of cadmium selenate nanowires, before and after irradiation were made with the help of Keithley 2400 source meter and Ecopia probe station. A significant change in the electrical conductivity of cadmium selenate nanowires was found after gamma irradiation. The crystallography of the synthesized nanowires was also studied using a Rigaku X-ray diffractrometer equipped with Cu-Kα radiation. XRD patterns of irradiated samples showed no variation in the peak positions or phase change.

  9. Insulin Expression in Rats Exposed to Cadmium

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objectives To investigate the effects of cadmium exposure on insulin expression in rats. Methods Eighteen adult SD assessed. The levels of cadmium and zinc in pancreas, blood and urine glucose, serum insulin and urine NAG (N-acyetyl-β-glucosaminidase) were determined. The gene expressions of metallothionein (MT) and insulin were also measured,and the oral glucose tolerance tests (OGTT) were carried out. Results The contents of cadmium in pancreas in cadmium-treated rats were higher than that in the control group, which was associated with slight increase of zinc in pancreas.not change significantly after cadmium administration, and the UNAG had no change in Cd-treated group. The gene expression the change of the expression of insulin, MT-Ⅰ and MT-Ⅱ genes. Cadmium can influence the biosynthesis of insulin, but does not induce the release of insulin. The dysfunction of pancreas occurs earlier than that of kidney after administration of cadmium.

  10. 稳定性同位素探针技术在土壤功能微生物原位鉴定的应用%Application of Stable Isotope Probing on In-situ Identification of Soil Functional Microorganism

    Institute of Scientific and Technical Information of China (English)

    蔺中; 孙礼勇; 陈昊; 孙迎韬; 白婧; 李永涛

    2012-01-01

    新近发展起来的稳定性同位素探针技术(SIP)与分子生物学方法结合,能够定向发掘复杂环境中参与特定生态过程的微生物资源,是土壤功能微生物原位鉴定的有效手段,具有广阔的应用前景.其原理是环境样品中的功能微生物代谢同化同位素标记的底物,通过对其生物标志物(即DNA、RNA、PLFA等)进行提取、分离、鉴定和比对分析,以此获取介导土壤物质转化和循环过程的功能微生物的直接信息.本文在分别介绍SIP技术在土壤功能微生物原位鉴定过程中的各种前处理方法、生物标志物选择及后续鉴定方法的基础上,综述了SIP技术在研究驱动土壤有机污染物生物降解、碳氮循环等过程的功能微生物原位鉴定的应用进展,展望了SIP技术在土壤微生物基因组学方面的应用前景.%Utilization of stable isotope probing( SIP) coupled with molecular biology method, can explore microorganisms source responsible for specific process in natural environment, and has a broad application prospects for soil functional microorganism in situ identification. The principle of the SIP technique is as follows. Functional microorganisms in soil samples, that metabolize the SIP-labeled substrates and assimilate SIP-labeled biomarkers, e.g., DNA, RNA and PLFA, can be identified by extraction, separation and analysis of these SIP-labeled biomarkers, and then information of soil functional microorganisms responsible for transformation and cyclic process of substrate in soil can be obtained directly as a result. With introduction of pre-treatment technology, SIP-labeled biomarker selection, and subsequent microorganisms' identification method, this study illustrates the research progress of SIP technique in in-situ identification of functional microorganisms involving in the soil organic pollutants degradation, carbon and nitrogen cycle. It will provide a comprehensive reference for the application and

  11. Laser spectroscopy of tin and cadmium: across N=82 and closing in on N=50

    CERN Multimedia

    We propose to study the isotopes of tin starting in proximity of N = 50 up to and beyond N = 82, as well as the "magic-plus-one" nuclei of cadmium at both shell closures. The objective is to determine model-independent properties of ground and isomeric states by high-resolution laser spectroscopy, which are essential for understanding the structure of nuclei and their astrophysical importance in this region of the nuclear chart.

  12. Collinear laser spectroscopy of atomic cadmium

    CERN Document Server

    Frömmgen, Nadja; Bissell, Mark L; Bieroń, Jacek; Blaum, Klaus; Cheal, Bradley; Flanagan, Kieran; Fritzsche, Stephan; Geppert, Christopher; Hammen, Michael; Kowalska, Magdalena; Kreim, Kim; Krieger, Andreas; Neugart, Rainer; Neyens, Gerda; Rajabali, Mustafa M; Nörtershäuser, Wilfried; Papuga, Jasna; Yordanov, Deyan T

    2015-01-01

    Hyperfine structure $A$ and $B$ factors of the atomic $5s\\,5p\\,\\; ^3\\rm{P}_2 \\rightarrow 5s\\,6s\\,\\; ^3\\rm{S}_1$ transition are determined from collinear laser spectroscopy data of $^{107-123}$Cd and $^{111m-123m}$Cd. Nuclear magnetic moments and electric quadrupole moments are extracted using reference dipole moments and calculated electric field gradients, respectively. The hyperfine structure anomaly for isotopes with $s_{1/2}$ and $d_{5/2}$ nuclear ground states and isomeric $h_{11/2}$ states is evaluated and a linear relationship is observed for all nuclear states except $s_{1/2}$. This corresponds to the Moskowitz-Lombardi rule that was established in the mercury region of the nuclear chart but in the case of cadmium the slope is distinctively smaller than for mercury. In total four atomic and ionic levels were analyzed and all of them exhibit a similar behaviour. The electric field gradient for the atomic $5s\\,5p\\,\\; ^3\\mathrm{P}_2$ level is derived from multi-configuration Dirac-Hartree-Fock calculatio...

  13. Modulation of cadmium bioaccumulation and enhancing cadmium tolerance in Pichia kudriavzevii by sodium chloride preincubation.

    Science.gov (United States)

    Ma, Ning; Li, Chunsheng; Zhang, Dandan; Yu, Jinzhi; Xu, Ying

    2016-07-01

    Application of growing microorganisms for cadmium removal is limited by the sensitivity of living cells to cadmium. The effects of sodium chloride (NaCl) preincubation on the cadmium bioaccumulation and tolerance of Pichia kudriavzevii and Saccharomyces cerevisiae were investigated in this study. NaCl preincubation significantly reduced the intracellular and cell-surface cadmium bioaccumulation of P. kudriavzevii at both 6 and 20 mg L(-1) cadmium, while no obvious effect was observed in S. cerevisiae except that the intracellular cadmium bioaccumulation at 20 mg L(-1) cadmium was reduced obviously by 20-60 g L(-1)  NaCl. For both yeasts, the improved contents of protein and proline after NaCl preincubation contributed to the cadmium tolerance. The thiol contents in P. kudriavzevii under cadmium stress were alleviated by NaCl preincubation, which might be due to the decrease of intracellular cadmium bioaccumulation. NaCl preincubation enhanced the contents of glycerol and trehalose in P. kudriavzevii under cadmium stress, while no acceleration was observed in S. cerevisiae. The results suggested that NaCl preincubation could be applied in cadmium removal by growing P. kudriavzevii to increase the cadmium tolerance of the yeast.

  14. Bioaccumulation of cadmium by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae.

    Science.gov (United States)

    Li, Chunsheng; Jiang, Wei; Ma, Ning; Zhu, Yinglian; Dong, Xiaoyan; Wang, Dongfeng; Meng, Xianghong; Xu, Ying

    2014-03-01

    Bioaccumulation via growing cells is a potential technique for heavy metal removal from food materials. The cadmium bioaccumulation characteristics by growing Zygosaccharomyces rouxii and Saccharomyces cerevisiae were investigated. Z. rouxii displayed powerful cadmium removal ability at low cadmium concentrations, which mainly depended on the intracellular cadmium bioaccumulation. The percentage of intracellular cadmium bioaccumulation of both yeasts obviously decreased with the increase of initial biomass and cadmium concentrations. Low pH and elevated concentrations of zinc and copper significantly decreased the intracellular cadmium bioaccumulation of both yeasts but improved the cadmium tolerance and the cell-surface cadmium bioaccumulation of Z. rouxii. Cadmium removal of Z. rouxii was improved by zinc and copper conditionally. Z. rouxii that possessed more powerful cadmium tolerance and removal ability at low pH and high concentration of competing ions can be developed into a potential cadmium removal agent using in complex food environment in future.

  15. Cadmium content of plants as affected by soil cadmium concentration

    Energy Technology Data Exchange (ETDEWEB)

    Lehoczky, E. [Pannon Univ. of Agricultural Sciences, Keszthely (Hungary); Szabados, I.; Marth, P. [Plant Health and Soil Conservation Station, Higany (Hungary)

    1996-12-31

    Pot experiments were conducted in greenhouse conditions to study the effects of increasing cadmium (Cd) levels on biomass production and Cd contents in corn, (Zea mays L.), garlic (Allium sativum L.), and spinach (Spinacia oleracea L.). Plants were grown in two soil types: Eutric cambisol soil and A gleyic luvisol soil. Spinach proved to be the most sensitive to Cd treatments as its biomass considerably decreased with the increasing Cd levels. Cadmium contents of the three crops increased with increasing levels of Cd applications. Statistical differences were observed in the Cd contents of crops depending on soil type. With the same Cd rates, Cd tissue concentration of test plants grown in the strongly acidic Gleyic luvisol soil were many times higher than that of plants grown in a neutral Eutric cambisol soil. 14 refs., 4 tabs.

  16. Tolerance to cadmium and cadmium-binding ligands in Great Salt Lake brine shrimp (Artemia salina)

    Energy Technology Data Exchange (ETDEWEB)

    Jayasekara, S.; Drown, D.B.; Sharma, R.P.

    1986-02-01

    Information on the accumulation of cadmium in cytosolic proteins of Great Lake brine shrimp (Artemia salina) was obtained from animals collected directly from the lake and also from animal hatched and maintained in three sublethal concentrations of cadmium (0.5, 2.0, 5.0 ppm) in saltwater aquaria. Brine shrimp growth under these conditions was monitored by measuring body lengths during a 7-day exposure period. Heat-stable, cadmium-binding ligands were isolated and identified by Sephadex G-75 chromatography and atomic absorption spectrophotometry. Cadmium was found to be equally distributed between high and low molecular weight proteins in animals collected from the lake and the 0.5 ppm cadmium group. There was also a slight growth stimulation noted in the 0.5-pm group. Higher cadmium incorporation was noted in low molecular weight fractions with increasing cadmium concentration in the exposure media. Low molecular weight fractions were also found to have high uv absorption characteristics at 250 nm and low absorption at 280 nm. Molecular weight of the cadmium-binding ligands was found to be 11,000 as estimated by the gel filtration method. De novo synthesis of this protein was increased as a function of cadmium concentration in the media. However, slow accumulation of cadmium in other protein fractions was also noticed in higher cadmium exposure groups, suggesting the existence of possible tolerance mechanisms in brine shrimp exposed to suspected acute cadmium concentrations.

  17. Zone refining of cadmium and related characterization

    Indian Academy of Sciences (India)

    N R Munirathnam; D S Prasad; Ch Sudheer; J V Rao; T L Prakash

    2005-06-01

    We present the zone refining results of cadmium using horizontal resistive zone refiner under constant flow of moisture free hydrogen gas. The boron impurity in cadmium can be avoided using quartz (GE 214 grade) boat in lieu of high pure graphite boat. The analytical results using inductively coupled plasma optical emission spectrometry (ICPOES) show that majority of the impurities are less than the detection limits. Comparatively, zinc is the most difficult impurity element to remove in cadmium matrix by zone refining.

  18. The Epigenetic Effects of Prenatal Cadmium Exposure.

    Science.gov (United States)

    Vilahur, Nadia; Vahter, Marie; Broberg, Karin

    2015-06-01

    Prenatal exposure to the highly toxic and common pollutant cadmium has been associated with adverse effects on child health and development. However, the underlying biological mechanisms of cadmium toxicity remain partially unsolved. Epigenetic disruption due to early cadmium exposure has gained attention as a plausible mode of action, since epigenetic signatures respond to environmental stimuli and the fetus undergoes drastic epigenomic rearrangements during embryogenesis. In the current review, we provide a critical examination of the literature addressing prenatal cadmium exposure and epigenetic effects in human, animal, and in vitro studies. We conducted a PubMed search and obtained eight recent studies addressing this topic, focusing almost exclusively on DNA methylation. These studies provide evidence that cadmium alters epigenetic signatures in the DNA of the placenta and of the newborns, and some studies indicated marked sexual differences for cadmium-related DNA methylation changes. Associations between early cadmium exposure and DNA methylation might reflect interference with de novo DNA methyltransferases. More studies, especially those including environmentally relevant doses, are needed to confirm the toxicoepigenomic effects of prenatal cadmium exposure and how that relates to the observed health effects of cadmium in childhood and later life.

  19. Conductivity Probe

    Science.gov (United States)

    2008-01-01

    The Thermal and Electrical Conductivity Probe (TECP) for NASA's Phoenix Mars Lander took measurements in Martian soil and in the air. The needles on the end of the instrument were inserted into the Martian soil, allowing TECP to measure the propagation of both thermal and electrical energy. TECP also measured the humidity in the surrounding air. The needles on the probe are 15 millimeters (0.6 inch) long. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  20. Pollution Probe.

    Science.gov (United States)

    Chant, Donald A.

    This book is written as a statement of concern about pollution by members of Pollution Probe, a citizens' anti-pollution group in Canada. Its purpose is to create public awareness and pressure for the eventual solution to pollution problems. The need for effective government policies to control the population explosion, conserve natural resources,…

  1. Improvement of cadmium phytoremediation after soil inoculation with a cadmium-resistant Micrococcus sp.

    Science.gov (United States)

    Sangthong, Chirawee; Setkit, Kunchaya; Prapagdee, Benjaphorn

    2016-01-01

    Cadmium-resistant Micrococcus sp. TISTR2221, a plant growth-promoting bacterium, has stimulatory effects on the root lengths of Zea mays L. seedlings under toxic cadmium conditions compared to uninoculated seedlings. The performance of Micrococcus sp. TISTR2221 on promoting growth and cadmium accumulation in Z. mays L. was investigated in a pot experiment. The results indicated that Micrococcus sp. TISTR2221significantly promoted the root length, shoot length, and dry biomass of Z. mays L. transplanted in both uncontaminated and cadmium-contaminated soils. Micrococcus sp. TISTR2221 significantly increased cadmium accumulation in the roots and shoots of Z. mays L. compared to uninoculated plants. At the beginning of the planting period, cadmium accumulated mainly in the shoots. With a prolonged duration of cultivation, cadmium content increased in the roots. As expected, little cadmium was found in maize grains. Soil cadmium was significantly reduced with time, and the highest percentage of cadmium removal was found in the bacterial-inoculated Z. mays L. after transplantation for 6 weeks. We conclude that Micrococcus sp. TISTR2221 is a potent bioaugmenting agent, facilitating cadmium phytoextraction in Z. mays L.

  2. Electrodialytic Removal of Cadmium from Straw Ash

    DEFF Research Database (Denmark)

    Hansen, Henrik; Ottosen, Lisbeth M.; Villumsen, Arne;

    1999-01-01

    A problem with flyash from straw and wood combustion is the high level of heavy metals, especially cadmium. Two electrodialytic remediation experiments were carried out on cadmium polluted flyash from straw combustion. The flyash could be cleaned to 1/3 of its initial level after 24 days...

  3. Cadmium and children : Exposure and health effects

    NARCIS (Netherlands)

    Schoeters, G.; Hond, E. Den; Zuurbier, M.; Naginiene, R.; Hazel, P.J. van den; Stilianakis, N.; Ronchetti, R.; Koppe, J.G.

    2006-01-01

    Cadmium exposure and accumulation in the body start at young age. Exposure routes in children are mainly via food, environmental tobacco smoke and house dust. Excretion from the body is limited. Cadmium accumulation in the kidney is responsible for effects such as nephrotoxicity and osteoporosis whi

  4. Cadmium and children: exposure and health effects.

    Science.gov (United States)

    Schoeters, Greet; Den Hond, Elly; Zuurbier, Moniek; Naginiene, Rima; van den Hazel, Peter; Stilianakis, Nikolaos; Ronchetti, Roberto; Koppe, Janna G

    2006-10-01

    Cadmium exposure and accumulation in the body start at young age. Exposure routes in children are mainly via food, environmental tobacco smoke and house dust. Excretion from the body is limited. Cadmium accumulation in the kidney is responsible for effects such as nephrotoxicity and osteoporosis which are observed at adult age. Cadmium exposure through inhalation is also associated with lung cancer in adulthood. Although transfer to the neonate through the placenta and through breast milk is limited, teratogenic and developmental effects were observed in experimental animals. The database on human studies involving children is limited, yet effects on motoric and perceptual behaviour in children have been associated with elevated in utero cadmium exposure. In school age children urinary cadmium levels were associated with immune suppressive effects. More studies are needed to confirm these results. Experimental data in vitro and in animals refer to effects of cadmium on the hypothalamus-pituitary axis at different levels. This may lead to disorders of the endocrine and/or immune system. Cadmium exposure at early age should be limited as much as possible to prevent direct effects on children and to prevent accumulation of cadmium which may have serious health effects only becoming manifest at older age.

  5. Immunoassay for Cadmium Detection and Quantification

    Institute of Scientific and Technical Information of China (English)

    GONG-LIANG LIU; JU-FANG WANG; ZHI-YONG LI; SHI-ZHONG LIANG; XIAO-NING WANG

    2009-01-01

    Objective To detect cadmium in environmental and food samples by graphite furnace atomic absorption spectroscopy (GFAAS) and inductively coupled plasma atomic emission spectroscopy (ICPAES). Methods An indirect competitive enzyme-linked immunosorbent assay (IC-ELISA) was developed based on a cadmium-specific monoclonal antibody.IC-ELISA for cadmium in environmental and food samples was evaluated. Results IC-ELISA showed an IC50 of 45.6 μg/L with a detection limit of 1.95 μg/L for cadmium,and showed a mean recovery ranging 97.67%-107.08%.The coefficient of variations for intra- and iuterassay was 3.41%-6.61% and 4.70%-9.21%,respectively.The correlation coefficient between IC-ELISA and GFAAS was 0.998. Conclusion IC-ELISA can detect and quantify cadmium residue in environmental or food samples.

  6. Cadmium a metalloestrogen: are we convinced?

    Science.gov (United States)

    Silva, Nalinda; Peiris-John, Roshini; Wickremasinghe, Rajitha; Senanayake, Hemantha; Sathiakumar, Nalini

    2012-05-01

    Metalloestrogens are inorganic metal ions that bind to and activate oestrogen receptors. They are implicated in the aetiology of oestrogen-dependent diseases such as cancers of the breast and endometrium as well as endometriosis. Cadmium is one of the most studied metalloestrogens. In this review, scientific evidence for the oestrogenic effects of cadmium is critically evaluated to determine if there is sufficient evidence to support cadmium as an aetiological factor of oestrogen-dependent disease in humans. Results of the review indicated that, although the in vitro and in vivo evidence of the oestrogenic properties of cadmium was persuasive, evidence from population-based human studies remains conflicting. Considerable knowledge gaps exist on the potential oestrogenic effect of cadmium in humans. Research that focuses on bridging these knowledge gaps would be useful in preventing and managing oestrogen-dependent disease in humans.

  7. Cadmium mobility and accumulation in soils of the European Communities

    NARCIS (Netherlands)

    Fraters B; van Beurden AUCJ

    1993-01-01

    In this overview of the effects of cadmium pollution on agricultural soils in the European Community, both the cadmium loads on agricultural land and the soil sensitivity to cadmium accumulation have been estimated. Cadmium loads have been estimated separately for arable land and grassland. The ef

  8. Sealed nickel-cadmium battery

    Energy Technology Data Exchange (ETDEWEB)

    1989-08-15

    Overcharge protection, and especially the chargeability of a sealed Ni/Cd battery with high currents is improved by rolling a carbon-containing powdered material into the surface of the negative electrode, which material catalyzes the reduction of oxygen. Wetting of the electrode with a Tylose dispersion prior to application of the powder (by powdering, vibration or in an agitator) improves the adhesion of the powder. The cadmium electrode thus prepared combines in itself the functions of a negative principal electrode and of an auxiliary oxygen electrode.

  9. Isotope Harvesting Opportunities at FRIB

    Science.gov (United States)

    Morrissey, David

    2017-01-01

    The fragmentation of fast heavy ion beams now at the National Superconducting Cyclotron Laboratory (NSCL) and in the future at the Facility for Rare Isotope Beams (FRIB) under construction produce an unprecedentedly broad spectrum of radionuclides but only a small fraction are used in the on-line rare-isotope program. Projectile fragmentation facilities provide an electromagnetically purified beam of a single projectile fragment for nuclear physics experiments ranging from low energy astrophysics, through nuclear structure studies, to probing fundamental symmetries. By augmenting the NSCL and FRIB production facilities with complimentary collection and purification of discarded ions, called isotope harvesting with chemical purification, many other nuclides will become available for off-line experiments in parallel with the primary experiment. A growing user community has established a list of key target isotopes and is working with the FRIB design team to allow inclusion of necessary equipment in the future. An overview of the possibilities and the techniques will be presented in this talk. Supported by Office of Science, US DOE and Michigan State University.

  10. Response of Saccharomyces cerevisiae to cadmium stress

    Energy Technology Data Exchange (ETDEWEB)

    Moreira, Luciana Mara Costa; Ribeiro, Frederico Haddad; Neves, Maria Jose [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil). Lab. de Radiobiologia], e-mail: luamatu@uol.com.br; Porto, Barbara Abranches Araujo; Amaral, Angela M.; Menezes, Maria Angela B.C. [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Lab. de Ativacao Neutronica], e-mail: menezes@cdtn.br; Rosa, Carlos Augusto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Dept. de Microbiologia], e-mail: carlrosa@icb.ufmg

    2009-07-01

    The intensification of industrial activity has been greatly contributing with the increase of heavy metals in the environment. Among these heavy metals, cadmium becomes a serious pervasive environmental pollutant. The cadmium is a heavy metal with no biological function, very toxic and carcinogenic at low concentrations. The toxicity of cadmium and several other metals can be mainly attributed to the multiplicity of coordination complexes and clusters that they can form. Some aspects of the cellular response to cadmium were extensively investigated in the yeast Saccharomyces cerevisiae. The primary site of interaction between many toxic metals and microbial cells is the plasma membrane. Plasma-membrane permeabilisation has been reported in a variety of microorganisms following cadmium exposure, and is considered one mechanism of cadmium toxicity in the yeast. In this work, using the yeast strain S. cerevisiae W303-WT, we have investigated the relationships between Cd uptake and release of cellular metal ions (K{sup +} and Na{sup +}) using neutron activation technique. The neutron activation was an easy, rapid and suitable technique for doing these metal determinations on yeast cells; was observed the change in morphology of the strains during the process of Cd accumulation, these alterations were observed by Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) during incorporation of cadmium. (author)

  11. Response of Pleurotus ostreatus to cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    Favero, N.; Bressa, G.; Costa, P. (Univ. of Padua (Italy))

    1990-08-01

    The possibility of utilizing agroindustrial wastes in the production of edible, high-quality products (e.g., mushrooms) implies the risk of bringing toxic substances, such as heavy metals, into the human food chain. Thus, growth in the presence of cadmium and cadmium accumulation limits have been studied in the industrially cultivated fungus P. ostreatus. Fruit body production is substantially unaffected in the presence of 25, 139, and 285 mg Cd/kg of dried substrate. Cadmium concentration in fruit bodies is related to cadmium substrate level, the metal being present at higher levels in caps (22-56 mg/kg dry wt) than in stems (13-36 mg/kg dry wt). Concentration factor (CF), very low in the controls (about 2), further decreases in treated specimens. The presence of a cadmium control mechanism in this fungi species is suggested. Fruit body cadmium levels could, however, represent a risk for P. ostreatus consumers, according to FAO/WHO limits related to weekly cadmium intake.

  12. Interactions of cadmium and zinc during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Sorell, T.L.

    1988-01-01

    The interactions of cadmium exposure and zinc during pregnancy were investigated by studying rats exposed to 0, 5, 50, or 100 ppm cadmium (as CdCl{sub 2}) in the drinking water from day 6 to day 20 of pregnancy. On day 20 of pregnancy, fetuses of rats exposed to 50 and 100 ppm of cadmium were slightly but significantly smaller than those of control animals. Fetal weight was negatively correlated with fetal cadmium concentration and positively correlated with fetal cadmium concentration. Significant fetal cadmium accumulation occurred in both the 50 and 100 ppm cadmium exposure groups; fetal zinc concentrations were decreased. Maternal liver and kidney zinc concentrations were slightly elevated, and the possible role of maternal organ sequestration of available zinc is discussed. The activity of two zinc metalloenzymes, alkaline phosphatase and {delta}-aminolevulinic acid dehydratase, was decreased in maternal and fetal tissues, providing evidence of an alteration in zinc metabolism. In addition, the placental transport of {sup 65}Zn was characterized in control animals and compared to exposed groups; placental zinc transport was significantly decreased in the 50 and 100 ppm exposure groups.

  13. Cadmium inhalation and male reproductive toxicity

    Energy Technology Data Exchange (ETDEWEB)

    Ragan, H.A.; Mast, T.J. (Battelle Pacific Northwest Laboratories, Richland, WA (USA))

    1990-01-01

    Cadmium is a highly toxic element that is cumulative and has a long biological half-life in mammals. The severe toxicity of cadmium in man has been known for more than 100 years. Despite the knowledge that cadmium is toxic, only 20 human cases of poisoning via ingestion were recorded prior to 1941, whereas in the ensuing five-year period more than 680 cases of cadmium poisonings from accidental oral ingestion of this metal were documented. Some of the recorded effects of exposure to cadmium in laboratory animals include renal tubular damage, placental and testicular necrosis, structural and functional liver damage, osteomalacia, testicular tumors, teratogenic malformations, anemia, hypertension, pulmonary edema, chronic pulmonary emphysema, and induced deficiencies of iron, copper, and zinc. Some of these effects have also been observed in human after accidental exposures to cadmium oxide fumes and are characteristic of the syndrome described in Japan as Itai Itai disease in which ingestion of cadmium is the inciting chemical.134 references.

  14. [Association between cadmium and breast cancer].

    Science.gov (United States)

    Strumylaite, Loreta; Bogusevicius, Algirdas; Ryselis, Stanislovas; Pranys, Darius; Poskiene, Lina; Kregzdyte, Rima; Abdrachmanovas, Olegas; Asadauskaite, Rūta

    2008-01-01

    Cadmium is a known human lung carcinogen, although some studies indicate a link between cadmium exposure and human breast cancer. The objective of this study was to assess cadmium concentration in breast tissue samples of patients with breast cancer and benign breast tumor. MATERIAL AND METHODS. The concentration of cadmium was determined in breast tissue samples of 21 breast cancer and 19 benign tumor patients. Two samples of breast tissue from each patient, i.e. tumor and normal tissue close to tumor, were taken for the analysis. Cadmium was determined by atomic absorption spectrometry (Perkin-Elmer, Zeeman 3030). RESULTS. In patients with breast cancer, the mean cadmium concentration was 33.1 ng/g (95% CI, 21.9-44.4) in malignant breast tissue and 10.4 ng/g (95% CI, 5.6-15.2) in normal breast tissue (P=0.002). In patients with benign tumor, the corresponding values were 17.5 ng/g (95% CI, 8.4-26.5) and 11.8 ng/g (95% CI, 5.1-18.5) (P=0.3144). There was a statistically significant difference in cadmium concentration between malignant and benign breast tissues (P=0.009). CONCLUSION. The data obtained show that cadmium concentration is significantly higher in malignant breast tissue as compared with normal breast tissue of the same women or benign breast tissue. Further studies are necessary to determine the association between cadmium concentration in malignant breast tissue and estrogen receptor level, and smoking.

  15. Biochemical Effects of Cadmium Exposure and the Potential Pharmacologic Significance of Cadmium Mediated Hydrolase Inhibition

    Science.gov (United States)

    1997-04-18

    increase Cd absorption from the intestines (Larson and Piscator 1971; Itokawa, Abe et al. 197 4; Pond and Walker 1975). Pyridoxine, vitamin B 6 , is...considerations on uptake and retention of cadmium in human kidney cortex. Cadmium in the Environment. L. Friberg, M. Piscator and G. F. Nordberg. Cleveland...Columbia, Missouri, University of Missouri. Larson, S.-E. and M. Piscator (1971). "Effect of cadmium on skeletal tissue in normal and calcium

  16. Cadmium Toxicity to Ringed Seals (Phoca hispida)

    DEFF Research Database (Denmark)

    Sonne, Christian; Dietz, R.; Riget, F. F.;

    as laboratory mammals. We have studied possible cadmium induced histopathological changes in the kidneys as well as a demineralisation of the skeletal system (DXA-scanning of lumbal vertebraes). No obvious cadmium induced toxic changes were found. Food composition and physiological adaptations may explain......Cadmium concentrations in kidneys from ringed seals (Phoca hispida) from North West Greenland (Qaanaaq) are high. Concentrations range at level known to induce renal toxic effects (mainly tubulopathy) and demineralisation (osteopenia) of the skeletal system (Fanconi's Syndrome) in humans as well...

  17. Stable isotope studies

    Energy Technology Data Exchange (ETDEWEB)

    Ishida, T.

    1992-01-01

    The research has been in four general areas: (1) correlation of isotope effects with molecular forces and molecular structures, (2) correlation of zero-point energy and its isotope effects with molecular structure and molecular forces, (3) vapor pressure isotope effects, and (4) fractionation of stable isotopes. 73 refs, 38 figs, 29 tabs.

  18. RISK ASSESSMENT AND MANAGEMENT OF ENVIRONMENTAL CADMIUM

    Science.gov (United States)

    Cadmium consumed in foods grown on soils contaminated by industrial Cd+Zn discharge has caused renal tubular dysfunction in exposed humans in discrete situations. However, lack of understanding about environmental Cd has caused wide concern that generalpopulations may...

  19. Some Aspects of Sealed Nickel Cadmium Cells

    Directory of Open Access Journals (Sweden)

    P. K. Saha

    1967-11-01

    Full Text Available Sealed Nickel Cadmium Cell system is termed till today as the most reliable power pack for electronic apparatus specially in low temperature use. This paper brings out the development and production of sealed nickel cadmium cells of pocket plate construction. The author who has gained experience in production of Ni-Cd cells in East Germany discusses also the major problems faced by the battery manufactures of to-day.

  20. Combining solvent isotope effects with substrate isotope effects in mechanistic studies of alcohol and amine oxidation by enzymes.

    Science.gov (United States)

    Fitzpatrick, Paul F

    2015-11-01

    Oxidation of alcohols and amines is catalyzed by multiple families of flavin- and pyridine nucleotide-dependent enzymes. Measurement of solvent isotope effects provides a unique mechanistic probe of the timing of the cleavage of the OH and NH bonds, necessary information for a complete description of the catalytic mechanism. The inherent ambiguities in interpretation of solvent isotope effects can be significantly decreased if isotope effects arising from isotopically labeled substrates are measured in combination with solvent isotope effects. The application of combined solvent and substrate (mainly deuterium) isotope effects to multiple enzymes is described here to illustrate the range of mechanistic insights that such an approach can provide. This article is part of a Special Issue entitled: Enzyme Transition States from Theory and Experiment.

  1. Screening micro-organisms for cadmium absorption from aqueous solution and cadmium absorption properties of Arthrobacter nicotianae.

    Science.gov (United States)

    Tsuruta, Takehiko; Umenai, Daishi; Hatano, Tomonobu; Hirajima, Tsuyoshi; Sasaki, Keiko

    2014-01-01

    To obtain basic information on how microbial cells absorb cadmium from aqueous solution, we examined cadmium absorption in various micro-organisms. Of 51 micro-organism strains tested, we found that some Gram-positive bacteria, such as, Arthrobacter nicotianae and Bacillus subtilis, and some actinomycetes, such as, Streptomyces flavoviridis and S. levoris were highly capable of absorbing cadmium from an aqueous solution. A. nicotianae absorbed the largest amount of cadmium, over 800 μmol cadmium per gram of dry wt. cells. However, cadmium absorption by A. nicotianae was affected by the solution pH, cadmium concentration, and cell density. The absorption of cadmium was very rapid. Some factors that affected cadmium absorption by A. nicotianae cells were also discussed.

  2. Cadmium exposure and breast cancer risk.

    Science.gov (United States)

    McElroy, Jane A; Shafer, Martin M; Trentham-Dietz, Amy; Hampton, John M; Newcomb, Polly A

    2006-06-21

    Cadmium, a highly persistent heavy metal, has been categorized as a probable human carcinogen by the U.S. Environmental Protection Agency. Primary exposure sources include food and tobacco smoke. We carried out a population-based case-control study of 246 women, aged 20-69 years, with breast cancer and 254 age-matched control subjects. We measured cadmium levels in urine samples by inductively coupled plasma mass spectrometry and conducted interviews by telephone to obtain information on known breast cancer risk factors. Odds ratios (ORs) and 95% confidence intervals (CIs) for breast cancer by creatinine-adjusted cadmium levels were calculated by multivariable analysis. Statistical tests were two-sided. Women in the highest quartile of creatinine-adjusted cadmium level (> or = 0.58 microg/g) had twice the breast cancer risk of those in the lowest quartile (cadmium level (P(trend) = .01). Based on this study, the absolute risk difference is 45 (95% CI = 0 to 77) per 100,000 given an overall breast cancer rate of 124 per 100,000. Whether increased cadmium is a causal factor for breast cancer or reflects the effects of treatment or disease remains to be determined.

  3. Stable isotopes of transition and post-transition metals as tracers in environmental studies

    Science.gov (United States)

    Bullen, Tomas D.; Baskaran, Mark

    2011-01-01

    The transition and post-transition metals, which include the elements in Groups 3–12 of the Periodic Table, have a broad range of geological and biological roles as well as industrial applications and thus are widespread in the environment. Interdisciplinary research over the past decade has resulted in a broad understanding of the isotope systematics of this important group of elements and revealed largely unexpected variability in isotope composition for natural materials. Significant kinetic and equilibrium isotope fractionation has been observed for redox sensitive metals such as iron, chromium, copper, molybdenum and mercury, and for metals that are not redox sensitive in nature such as cadmium and zinc. In the environmental sciences, the isotopes are increasingly being used to understand important issues such as tracing of metal contaminant sources and fates, unraveling metal redox cycles, deciphering metal nutrient pathways and cycles, and developing isotope biosignatures that can indicate the role of biological activity in ancient and modern planetary systems.

  4. Reviews of the environmental effects of pollutants: IV. Cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Hammons, A.S.; Huff, J.E.; Braunstein, H.M.; Drury, J.S.; Shriner, C.R.; Lewis, E.B.; Whitfield, B.L.; Towill, L.E.

    1978-06-01

    This report is a comprehensive, multidisciplinary review of the health and environmental effects of cadmium and specific cadmium derivatives. More than 500 references are cited. The cadmium body burden in animals and humans results mainly from the diet. In the United States, the normal intake of cadmium for adult humans is estimated at about 50 ..mu..g per day. Tobacco smoke is a significant additional source of cadmium exposure. The kidneys and liver together contain about 50% of the total cadmium body burden. Acute cadmium poisoning is primarily an occupational problem, generally from inhalation of cadmium fumes or dusts. In the general population, incidents of acute poisoning by inhaled or ingested cadmium or its compounds are relatively rare. The kidney is the primary target organ for toxicity from prolonged low-level exposure to cadmium. No causal relationship has been established between cadmium exposure and human cancer, although a possible link between cadmium and prostate cancer has been indicated. Cadmium has been shown to be teratogenic in rats, hamsters, and mice, but no such effects have been proven in humans. Cadmium has been reported to increase the frequency of chromosomal aberrations in cultured Chinese hamster ovary cells and in human peripheral leukocytes. The major concern about environmental cadmium is the potential effects on the general population. There is no substantial evidence of hazard from current levels of cadmium in air, water, or food. However, because cadmium is a cumulative poison and because present intake provides a relatively small safety margin, there are adequate reasons for concern over possible future increases in background levels.

  5. Ultrafast Relaxation Dynamics of Photo-excited Dirac Fermion in Three Dimensional Dirac Semimetal Cadmium Arsenide

    CERN Document Server

    Lu, Wei; Liu, Xuefeng; Lu, Hong; Li, Caizhen; Lai, Jiawei; Zhao, Chuan; Tian, Ye; Liao, Zhimin; Jia, Shuang; Sun, Dong

    2016-01-01

    Three dimensional (3D) Dirac semimetal exhibiting ultrahigh mobility has recently attracted enormous research interests as 3D analogues of graphene. From the prospects of future application toward electronic/optoelectronic devices with extreme performance, it is crucial to understand the relaxation dynamics of photo-excited carriers and their coupling with lattice. In this work, we report ultrafast transient reflection measurements of photo-excited carrier dynamics in cadmium arsenide (Cd3As2), which is among the most stable Dirac semimetals that have been confirmed experimentally. With low energy probe photon of 0.3 eV, photo-excited Dirac Fermions dynamics closing to Dirac point are probed. Through transient reflection measurements on bulk and nanoplate samples that have different doping intensities, and systematic probe wavelength, pump power and lattice temperature dependent measurements, the dynamical evolution of carrier distributions can be retrieved qualitatively using a two-temperature model. The pho...

  6. Ribosomal genes as early targets of cadmium-induced toxicity in Chironomus riparius larvae

    Energy Technology Data Exchange (ETDEWEB)

    Planello, R. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Martinez-Guitarte, J.L. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain); Morcillo, G. [Biologia Ambiental, Facultad de Ciencias, Universidad Nacional de Educacion a Distancia, Senda del Rey 9, 28040, Madrid (Spain)]. E-mail: gmorcillo@ccia.uned.es

    2007-02-01

    Cadmium is a widespread environmental pollutant that causes severe impacts in organisms. Although the effects of cadmium on aquatic insects have been studied in terms of their toxicity and changes in developmental parameters, little is known about its molecular and genetic effects. We have investigated the alterations in the pattern of gene expression provoked by acute exposure to cadmium in Chironomus riparius Mg. (Diptera, Chironomidae), a sentinel organism widely used in aquatic toxicity testing. The early cytotoxic effects were evaluated using immunocytochemistry and specific fluorescent probes in fourth instar larvae after 12 h of 10 mM cadmium treatments; under these conditions no significant effect on larvae mortality was detected until after 36 h of exposure. The changes in the pattern of gene expression were analysed by means of DNA/RNA hybrid antibodies in the polytene chromosomes from salivary gland cells. A decrease in the activity of the nucleolus is especially remarkable, accompanied by a significant reduction in size and the modification in nucleolar architecture, as shown by FISH. The inhibition of rDNA transcription was further evaluated by Northern blot analysis, which showed a marked decrease in the level of preribosomal rRNA (54% 45S 12 h). However, the BR genes, whose products are the giant polypeptides that constitute the silk-like secretion for constructing housing tubes, remain active. Simultaneously, decondensation and activation take place at some chromosomal regions, especially at the centromeres. The changes observed in the pattern of gene expression do not resemble those found after heat shock or other cell stressors. These data provide the first evidence that cadmium interacts with ribosomal genes and results in a drastic impairment of the functional activity of the nucleolus, an essential organelle for cellular survival. Therefore, the depletion of ribosomes would be a long-term effect of Cd-induced cellular damage. These findings may

  7. Identification of three relationships linking cadmium accumulation to cadmium tolerance and zinc and citrate accumulation in lettuce.

    Science.gov (United States)

    Zorrig, Walid; Rouached, Aïda; Shahzad, Zaigham; Abdelly, Chedly; Davidian, Jean-Claude; Berthomieu, Pierre

    2010-10-15

    Lettuce (Lactuca sativa) is a plant species that shows high accumulation of cadmium, a toxic heavy metal. Lettuce is therefore a good model both for identifying determinants controlling cadmium accumulation in plant tissues and for developing breeding strategies aimed at limiting cadmium accumulation in edible tissues. In this work, 14-day-old plants from three lettuce varieties were grown for 8 days on media supplemented with cadmium concentrations ranging from 0 to 50 microM. Growth, as well as Cd(2+), Zn(2+), K(+), Ca(2+), NO(3)(-), SO(4)(2-), Cl(-), phosphate, malate and citrate root an shoot contents were analyzed. The three lettuce varieties Paris Island Cos, Red Salad Bowl and Kordaat displayed differential abilities to accumulate cadmium in roots and shoots, Paris Island Cos displaying the lowest cadmium content and Kordaat the highest. From the global analysis of the three varieties, three main trends were identified. First, a common negative correlation linked cadmium tissue content and relative dry weight reduction in response to cadmium treatments in the three varieties. Second, increasing cadmium concentration in the culture medium resulted in a parallel increase in zinc tissue content in all lettuce varieties. A common strong positive correlation between cadmium and zinc contents was observed for all varieties. This suggested that systems enabling zinc and cadmium transport were induced by cadmium. Finally, the cadmium treatments had a contrasting effect on anion contents in tissues. Interestingly, citrate content in shoots was correlated with cadmium translocation from roots to shoots, suggesting that citrate might play a role in cadmium transport in the xylem vessels. Altogether, these results shed light on three main strategies developed by lettuce to cope with cadmium, which could help to develop breeding strategies aimed at limiting cadmium accumulation in lettuce.

  8. Cadmium exposure induces hematuria in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Han, Seung Seok [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Kim, Myounghee, E-mail: dkkim73@gmail.com [Department of Dental Hygiene, College of Health Science, Eulji University, Gyeonggi-do 461-713 (Korea, Republic of); Lee, Su Mi [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lee, Jung Pyo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Sejoong [Department of Internal Medicine, Seoul National University Bundang Hospital, Gyeonggi-do 463-707 (Korea, Republic of); Joo, Kwon Wook [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of); Lim, Chun Soo [Department of Internal Medicine, Seoul National University Boramae Medical Center, Seoul 156-707 (Korea, Republic of); Kim, Yon Su; Kim, Dong Ki [Department of Internal Medicine, Seoul National University College of Medicine, Seoul 110-744 (Korea, Republic of)

    2013-07-15

    Introduction: Toxic heavy metals have adverse effects on human health. However, the risk of hematuria caused by heavy metal exposure has not been evaluated. Methods: Data from 4701 Korean adults were obtained in the Korean National Health and Nutritional Examination Survey (2008–2010). Blood levels of the toxic heavy metals cadmium, lead, and mercury were measured. Hematuria was defined as a result of ≥+1 on a urine dipstick test. The odds ratios (ORs) for hematuria were measured according to the blood heavy metal levels after adjusting for multiple variables. Results: Individuals with blood cadmium levels in the 3rd and 4th quartiles had a greater OR for hematuria than those in the 1st quartile group: 3rd quartile, 1.35 (1.019–1.777; P=0.037); 4th quartile, 1.52 (1.140–2.017; P=0.004). When blood cadmium was considered as a log-transformed continuous variable, the correlation between blood cadmium and hematuria was significant: OR, 1.97 (1.224–3.160; P{sub trend}=0.005). In contrast, no significant correlations between hematuria and blood lead or mercury were found in the multivariate analyses. Discussion: The present study shows that high cadmium exposure is associated with a risk of hematuria. -- Highlights: • A high level of blood cadmium is associated with a high risk of hematuria. • This correlation is independent of several confounding factors. • Blood levels of lead and mercury are not associated with risk of hematuria. • This is the first study on the correlation between cadmium exposure and hematuria risk.

  9. Hazards to wildlife from soil-borne cadmium reconsidered

    Science.gov (United States)

    Beyer, W.N.

    2000-01-01

    Cadmium is a toxic element that should be included in environmental risk assessments of contaminated soils. This paper argues, however, that hazards to wildlife from cadmium have often been overstated. The literature contains only meager evidence that wild animals have been seriously harmed by cadmium, even at severely contaminated sites. Although some researchers have reported that wildlife have accumulated concentrations of cadmium in their kidneys that were above suggested injury thresholds, the thresholds may be disputed, since they were well below the World Health Organization criterion of 200 mg/kg (wet weight) of cadmium in the renal cortex for protecting human health. Recent risk assessments have concluded that soil cadmium concentrations less than 1 mg/kg are toxic to soil organisms and wildlife, which implies that background concentrations of cadmium naturally found in soils are hazardous. An examination of the databases used to support these assessments suggested that the toxicity of cadmium has been exaggerated.

  10. Proximal Probes Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Proximal Probes Facility consists of laboratories for microscopy, spectroscopy, and probing of nanostructured materials and their functional properties. At the...

  11. Isotope analysis in the transmission electron microscope

    CERN Document Server

    Susi, Toma; Argentero, Giacomo; Leuthner, Gregor T; Pennycook, Timothy J; Mangler, Clemens; Meyer, Jannik C; Kotakoski, Jani

    2016-01-01

    The {\\AA}ngstr\\"om-sized probe of the scanning transmission electron microscope can visualize and collect spectra from single atoms. This can unambiguously resolve the chemical structure of materials, but not their isotopic composition. Here we differentiate between two isotopes of the same element by quantifying how likely the energetic imaging electrons are to eject atoms. First, we measure the displacement probability in graphene grown from either $^{12}$C or $^{13}$C and describe the process using a quantum mechanical model of lattice vibrations coupled with density functional theory simulations. We then test our spatial resolution in a mixed sample by ejecting individual atoms from nanoscale areas spanning an interface region that is far from atomically sharp, mapping the isotope concentration with a precision better than 20%. Although we use a scanning instrument, our method should be applicable to any atomic resolution transmission electron microscope and to other low-dimensional materials.

  12. Modeling cadmium in the feed chain and cattle organs

    NARCIS (Netherlands)

    Fels-Klerx, van der H.J.; Romkens, P.F.A.M.; Franz, E.; Raamsdonk, van L.W.D.

    2011-01-01

    The objectives of this study were to estimate cadmium contamination levels in different scenarios related to soil characteristics and assumptions regarding cadmium accumulation in the animal tissues, using quantitative supply chain modeling. The model takes into account soil cadmium levels, soil pH,

  13. Epidemiological aspects of cadmium in the environment

    Energy Technology Data Exchange (ETDEWEB)

    Piscator, M.

    1973-01-01

    Cadmium is highly toxic to man and it has an extremely long biological half-time. Under long-term low level exposure about one third of the total body burden is in the kidneys. In some European countries and USA mean renal cortical concentrations of cadmium 24-50 ppM wet weight at age 50 have been reported. In three areas in Japan the corresponding concentrations were 60 to 125 ppM wet weight. These normal concentrations have been thought to cause hypertension but so far epidemiological data are not available to support such a hypothesis. Renal tubular dysfunction may begin at a renal cortical concentration of about 200 ppM wet weight. In Japan extensive investigations have been carried out in several areas polluted by cadmium. Available data indicate that the prevalence of proteinuria is higher in the cadmium polluted areas and that the proteinuria is of the tubular type. Studies on dose-response relationships must include accurate and sensitive methods for the detection of low molecular weight proteinuria, which is an early sign in cadmium intoxication. 6 references, 1 table.

  14. Recycling of Spent Nickel-Cadmium Batteries

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A technique for recycling spent nickel-cadmium batteries, which makes separation of cadmium and nickel possible, is developed by laboratory-scale experiments. NH3-H2CO3 aqueous solution was used in this leaching technique. Since neutralization and/or solvent extraction were not required in the separation procedure of nickel and cadmium, the closed systemization of the process becomes possible. Experimental results show that, (1) if the NH3 concentration of leaching solution is sufficiently high and the ratio of H2CO3 to NH3 is properly adjusted, both Ni(OH)2 and Cd(OH)2 react with NH3 and quickly dissolve into leaching solution, and (2) Ni(OH)2 can be converted into insoluble NiO by calcination at 500€癈, and CdO from Cd(OH)2 by calcination maintains good solubility in NH3-H2CO3 aqueous solution. As a conclusion, the recycling technique characterized by two step leaching can be developed based on such changes in dissolution behavior by calcination. Meanwhile, the yields of 99.8% for nickel and 97.6% for cadmium are obtained, and the purities of recovered nickel and cadmium are 99.9% and 98.6%, respectively.

  15. Iron isotope fractionation in marine invertebrates in near shore environments

    Science.gov (United States)

    Emmanuel, S.; Schuessler, J. A.; Vinther, J.; Matthews, A.; von Blanckenburg, F.

    2014-04-01

    Chitons (Mollusca) are marine invertebrates that produce radula (teeth or rasping tongue) containing high concentrations of biomineralized magnetite and other iron bearing minerals. As Fe isotope signatures are influenced by redox processes and biological fractionation, Fe isotopes in chiton radula might be expected to provide an effective tracer of ambient oceanic conditions and biogeochemical cycling. Here, in a pilot study to measure Fe isotopes in marine invertebrates, we examine Fe isotopes in modern marine chiton radula collected from different locations in the Atlantic and Pacific oceans to assess the range of isotopic values, and to test whether or not the isotopic signatures reflect seawater values. Furthermore, by comparing two species that have very different feeding habits but collected from the same location, we infer a possible link between diet and Fe isotopic signatures. Values of δ56Fe (relative to IRMM-014) in chiton teeth range from -1.90 to 0.00‰ (±0.05‰ (2σ) uncertainty in δ56Fe), probably reflecting a combination of geographical control and biological fractionation processes. Comparison with published local surface seawater Fe isotope data shows a consistent negative offset of chiton teeth Fe isotope compositions relative to seawater. Strikingly, two different species from the same locality in the North Pacific (Puget Sound, Washington, USA) have distinct isotopic signatures. Tonicella lineata, which feeds on red algae, has a mean δ56Fe of -0.65 ± 0.26‰ (2σ, 3 specimens), while Mopalia muscosa, which feeds primarily on green algae, shows lighter isotopic values with a mean δ56Fe of -1.47 ± 0.98‰ (2σ, 5 specimens). Although chitons are not simple recorders of the ambient seawater Fe isotopic signature, these preliminary results suggest that Fe isotopes provide information concerning Fe biogeochemical cycling in near shore environments, and might be used to probe sources of Fe in the diets of different organisms.

  16. Effect of anions on Toxicity of Cadmium Applied to MIcrobial Biomass in Red Soil

    Institute of Scientific and Technical Information of China (English)

    K.S.KHAN; XIEZHENGMIAO; 等

    1997-01-01

    A laboratory incubation experiment was conducted to elucidat the effects of associated anions on toxicity of cadmium applied to microbial biomass in the red soil. Cadmium was applied at six different levels,i.e.,O(background),5,15,30,60 and 100μg g-1 soil in the form of either cadmium acetate or cadmium chloride. Application of cadmium as cadmium acetate markedly reduced the soil microbial biomass carbon compared to cadmium applied as cadmium chlorde at all the tested levels.Similarly,organic carbon to biomass carbon ration in the soil was markedly increased by increasing the level of the cadmium in the soil as cadmium acetate,while the change wa much smaller in the case of cadmium chloride at the same cadmium levels.The results suggested that due consideration should be given to the source of cadmium while deciding the cadmium levles in experiments.

  17. Miniaturized In Situ Atmospheric Probe Sampling Inlet System for Uranus or Saturn Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Thorleaf Research, Inc. proposes to develop a miniaturized in situ atmospheric probe sampling inlet system for measuring chemical and isotopic composition of the...

  18. Statistical clumped isotope signatures

    NARCIS (Netherlands)

    Röckmann, T.; Popa, M. E.; Krol, M. C.; Hofmann, M. E. G.

    2016-01-01

    High precision measurements of molecules containing more than one heavy isotope may provide novel constraints on element cycles in nature. These so-called clumped isotope signatures are reported relative to the random (stochastic) distribution of heavy isotopes over all available isotopocules of a m

  19. Production of medical isotopes from a thorium target irradiated by light charged particles up to 70 MeV.

    Science.gov (United States)

    Duchemin, C; Guertin, A; Haddad, F; Michel, N; Métivier, V

    2015-02-07

    The irradiation of a thorium target by light charged particles (protons and deuterons) leads to the production of several isotopes of medical interest. Direct nuclear reaction allows the production of Protactinium-230 which decays to Uranium-230 the mother nucleus of Thorium-226, a promising isotope for alpha radionuclide therapy. The fission of Thorium-232 produces fragments of interest like Molybdenum-99, Iodine-131 and Cadmium-115g. We focus our study on the production of these isotopes, performing new cross section measurements and calculating production yields. Our new sets of data are compared with the literature and the last version of the TALYS code.

  20. Reduction of Cadmium Uptake of Rice Plants Using Soil Amendments in High Cadmium Contaminated Soil: A Pot Experiment

    Directory of Open Access Journals (Sweden)

    Dian Siswanto

    2013-05-01

    Full Text Available The aims of this study were to investigate the effect of agricultural residues on reducing cadmium uptake in rice plants. The rice plants growing on no cadmium/free cadmium soils (N, Cd soils (Cds, and Cd soils each amended with 1% w/w of coir pith (CP, coir pith modified with sodium hydroxide (CPm and corncob (CC under high cadmium contaminated soil with an average 145 mg Cd kg-1 soil were investigated. The results showed that the cumulative transpiration of rice grown in various treatments under high cadmium contaminated soil followed the order: Cds > CPm ≥ CP ≥ CC. These transpirations directly influenced cadmium accumulation in shoots and husks of rice plants. The CC and CP seemed to work to reduce the cadmium uptake by rice plants indicated by accumulated cadmium in the husk that were 2.47 and 7.38 mg Cd kg-1 dry weight, respectively. Overall, transpiration tended to drive cadmium accumulation in plants for rice grown in high cadmium contaminated soil. The more that plants uptake cadmium, the lower cadmium that remains in the soil.

  1. Cadmium accumulation by Axonopus compressus (Sw. P. Beauv and Cyperus rotundas Linn growing in cadmium solution and cadmium-zinc contaminated soil

    Directory of Open Access Journals (Sweden)

    Paitip Thiravetyan

    2007-05-01

    Full Text Available This research investigated the phyto-remediation potentials of Cyperus rotundas Linn (Nutgrass and Axonopus compressus (Sw. P. Beauv (Carpetgrass for cadmium removal from cadmium solution andcadmium-zinc contaminated soil. Plants growth in the solution showed that cadmium decreased the relative growth rate of both grasses. However, the amount of cadmium accumulated in shoot and root was increasedwith the increase in cadmium concentration and exposure time. Growth in fertile soil mixed with Cd-contaminated zinc silicate residue (65% Si, 19% Ca, 2% Zn, 1% Mg and 0.03% Cd at the ratio of 50:50 (w/wfor 30 days showed that C. rotundas Linn accumulated cadmium in root and shoot to 2,178 and 1,144 mg kg-1 dry weight, respectively. A. compressus (Sw. P. Beauv accumulated cadmium in root and shoot to 1,965and 669 mg kg-1 dry weight, respectively. Scanning electron microscope connected to energy-dispersive X-ray spectroscopy suggested that the mechanism of cadmium accumulation by both grasses involved thecadmium precipitation in the stable form of cadmium silicate, which indicated that C. rotundas Linn and A. compressus (Sw. P. Beauv could be grown to prevent soil erosion and to remediate cadmium-contaminatedsoil.

  2. ELECTROKINETIC REMEDIATION STUDY FOR CADMIUM CONTAMINATED SOIL

    Directory of Open Access Journals (Sweden)

    P. Bala Ramudu

    2007-09-01

    Full Text Available This paper presents the results of an experimental research undertaken to evaluate different purging solutions to enhance the removal of cadmium from spiked contaminated field soil by electrokinetic remediation. Three experiments were conducted when soil was saturated with deionised water and subsequently deionised water, ammonium citrate and sodium citrate were used as purging solutions at anode end. One experiment was conducted when the soil was saturated with ammonium citrate and itself was used as the purging solution. Results showed that 49% reduction of cadmium concentration was achieved in the case of soil saturated (washed with ammonium citrate as well as purging solution also was ammonium citrate. The soil pH and washing solutions were the most important factors in controlling the removal of cadmium in electrokinetic remediation process.

  3. Deposition of Cadmium Sulphide Thin Films by Photochemical Deposition and Characterization

    Directory of Open Access Journals (Sweden)

    H.L. Pushpalatha

    2015-03-01

    Full Text Available Deposition of cadmium sulphide (CdS thin films on glass substrates in acidic medium by photochemical deposition (PCD and studies by several characterizations are presented. The structural characterization of the thin films was carried out by XRD. The elemental composition of the thin films was carried out by EDAX. The optical properties have been studied in the wavelength range 200-900 nm and the optical transition has been found to be direct and allowed. The morphological properties are studied by AFM and electrical properties are studied by four probe technique.

  4. Isotopes in heterogeneous catalysis

    CERN Document Server

    Hargreaves, Justin SJ

    2006-01-01

    The purpose of this book is to review the current, state-of-the-art application of isotopic methods to the field of heterogeneous catalysis. Isotopic studies are arguably the ultimate technique in in situ methods for heterogeneous catalysis. In this review volume, chapters have been contributed by experts in the field and the coverage includes both the application of specific isotopes - Deuterium, Tritium, Carbon-14, Sulfur-35 and Oxygen-18 - as well as isotopic techniques - determination of surface mobility, steady state transient isotope kinetic analysis, and positron emission profiling.

  5. Generation of Radixenon Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    McIntyre, Justin I.; Bowyer, Ted W.; Hayes, James C.; Heimbigner, Tom R.; Morris, Scott J.; Panisko, Mark E.; Pitts, W. K.; Pratt, Sharon L.; Reeder, Paul L.; Thomas, Charles W.

    2003-06-30

    Pacific Northwest National Laboratory has developed an automated system for separating Xe from air and can detect the following radioxenon isotopes, 131mXe, 133mXe, 133Xe, and 135Xe. This report details the techniques used to generate the various radioxenon isotopes that are used for the calibration of the detector as well as other isotopes that have the potential to interfere with the fission produced radioxenon isotopes. Fission production is covered first using highly enriched uranium followed by a description and results from an experiment to produce radioxenon isotopes from neutron activation of ambient xenon.

  6. Probe tip heating assembly

    Science.gov (United States)

    Schmitz, Roger William; Oh, Yunje

    2016-10-25

    A heating assembly configured for use in mechanical testing at a scale of microns or less. The heating assembly includes a probe tip assembly configured for coupling with a transducer of the mechanical testing system. The probe tip assembly includes a probe tip heater system having a heating element, a probe tip coupled with the probe tip heater system, and a heater socket assembly. The heater socket assembly, in one example, includes a yoke and a heater interface that form a socket within the heater socket assembly. The probe tip heater system, coupled with the probe tip, is slidably received and clamped within the socket.

  7. Cadmium toxicity in the free-living nematode, Caenorhabditis elegans

    Energy Technology Data Exchange (ETDEWEB)

    Popham, J.D.; Webster, J.M.

    1979-10-01

    The effect of cadmium on the fecundity, growth, and fine structure of the free-living nematode Caenorhabditis elegans was studied. High concentrations of cadmium significantly decreased the fecundity and growth of these organisms. Electron microscopy showed that cadmium modifies the structure of the mitochondria in the esophagus and intestine, causes the formation of inclusion bodies in the nucleus of esophageal cells, and alters the morphology of cytosomes in the intestinal cells. The results suggest that the decreased fecundity and growth of cadmium-exposed C. elegans may be due to cadmium interfering with nutrient uptake or assimilation or both.

  8. Treatment of cadmium dust with two-stage leaching process

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The treatment of cadmium dust with a two-stage leaching process was investigated to replace the existing sulphation roast-leaching processes. The process parameters in the first stage leaching were basically similar to the neutralleaching in zinc hydrometallurgy. The effects of process parameters in the second stage leaching on the extraction of zincand cadmium were mainly studied. The experimental results indicated that zinc and cadmium could be efficiently recoveredfrom the cadmium dust by two-stage leaching process. The extraction percentages of zinc and cadmium in two stage leach-ing reached 95% and 88% respectively under the optimum conditions. The total extraction percentage of Zn and Cdreached 94%.

  9. Cadmium telluride quantum dots advances and applications

    CERN Document Server

    Donegan, John

    2013-01-01

    Optical Properties of Bulk and Nanocrystalline Cadmium Telluride, Núñez Fernández and M.I. VasilevskiyAqueous Synthesis of Colloidal CdTe Nanocrystals, V. Lesnyak, N. Gaponik, and A. EychmüllerAssemblies of Thiol-Capped CdTe Nanocrystals, N. GaponikFörster Resonant Energy Transfer in CdTe Nanocrystal Quantum Dot Structures, M. Lunz and A.L. BradleyEmission of CdTe Nanocrystals Coupled to Microcavities, Y.P. Rakovich and J.F. DoneganBiological Applications of Cadmium Telluride Semiconductor Quantum Dots, A. Le Cign

  10. Environmental cadmium and breast cancer risk

    OpenAIRE

    2010-01-01

    Breast cancer is the most prevalent women's cancer, with an age-adjusted incidence of 122.9 per 100,000 US women. Cadmium, a ubiquitous carcinogenic pollutant with multiple biological effects, has been reported to be associated with breast cancer in one US regional case-control study. We examined the association of breast cancer with urinary cadmium (UCd), in a case-control sample of women living on Long Island (LI), NY (100 with breast cancer and 98 without), a region with an especially high...

  11. Fluorescent porous silicon biological probes with high quantum efficiency and stability.

    Science.gov (United States)

    Tu, Chang-Ching; Chou, Ying-Nien; Hung, Hsiang-Chieh; Wu, Jingda; Jiang, Shaoyi; Lin, Lih Y

    2014-12-01

    We demonstrate porous silicon biological probes as a stable and non-toxic alternative to organic dyes or cadmium-containing quantum dots for imaging and sensing applications. The fluorescent silicon quantum dots which are embedded on the porous silicon surface are passivated with carboxyl-terminated ligands through stable Si-C covalent bonds. The porous silicon bio-probes have shown photoluminescence quantum yield around 50% under near-UV excitation, with high photochemical and thermal stability. The bio-probes can be efficiently conjugated with antibodies, which is confirmed by a standard enzyme-linked immunosorbent assay (ELISA) method.

  12. Cadmium Exposure and Pancreatic Cancer in South Louisiana

    Directory of Open Access Journals (Sweden)

    Brian G. Luckett

    2012-01-01

    Full Text Available Cadmium has been hypothesized to be a pancreatic carcinogen. We test the hypothesis that cadmium exposure is a risk factor for pancreatic cancer with a population-based case-control study sampled from a population with persistently high rates of pancreatic cancer (south Louisiana. We tested potential dietary and nondietary sources of cadmium for their association with urinary cadmium concentrations which reflect long-term exposure to cadmium due to the accumulation of cadmium in the kidney cortex. Increasing urinary cadmium concentrations were significantly associated with an increasing risk of pancreatic cancer (2nd quartile OR = 3.34, 3rd = 5.58, 4th = 7.70; test for trend P≤0.0001. Potential sources of cadmium exposure, as documented in the scientific literature, found to be statistically significantly associated with increased risk of pancreatic cancer included working as a plumber, pipefitter or welder (OR = 5.88 and high consumption levels of red meat (4th quartile OR = 6.18 and grains (4th quartile OR = 3.38. Current cigarette smoking, at least 80 pack years of smoking, occupational exposure to cadmium and paints, working in a shipyard, and high consumption of grains were found to be statistically significantly associated with increased concentrations of urinary cadmium. This study provides epidemiologic evidence that cadmium is a potential human pancreatic carcinogen.

  13. Cadmium-induced cancers in animals and in humans.

    Science.gov (United States)

    Huff, James; Lunn, Ruth M; Waalkes, Michael P; Tomatis, Lorenzo; Infante, Peter F

    2007-01-01

    Discovered in the early 1800s, the use of cadmium and various cadmium salts started to become industrially important near the close of the 19th century, rapidly thereafter began to flourish, yet has diminished more recently. Most cadmium used in the United States is a byproduct from the smelting of zinc, lead, or copper ores, and is used to manufacture batteries. Carcinogenic activity of cadmium was discovered first in animals and only subsequently in humans. Cadmium and cadmium compounds have been classified as known human carcinogens by the International Agency for Research on Cancer and the National Toxicology Program based on epidemiologic studies showing a causal association with lung cancer, and possibly prostate cancer, and studies in experimental animals, demonstrating that cadmium causes tumors at multiple tissue sites, by various routes of exposure, and in several species and strains. Epidemiologic studies published since these evaluations suggest that cadmium is also associated with cancers of the breast, kidney, pancreas, and urinary bladder. The basic metal cationic portion of cadmium is responsible for both toxic and carcinogenic activity, and the mechanism of carcinogenicity appears to be multifactorial. Available information about the carcinogenicity of cadmium and cadmium compounds is reviewed, evaluated, and discussed.

  14. Study of cadmium electrochemical deposition in sulfate medium

    Energy Technology Data Exchange (ETDEWEB)

    Montiel, T.; Solorza, O.; Sanchez, H.

    2000-03-01

    The cadmium electrochemical deposition process from sulfate medium was studied by means of different electrochemical techniques in both stationary and nonstationary diffusion regimes. The kinetics of the electrochemical reduction of cadmium on solid cadmium electrodes was examined and the kinetic parameters are presented, as well as the diffusion coefficient derived from the different techniques. Temperature has an important effect on the cadmium reduction kinetics, and the activation energy of the process was evaluated. The electrochemical deposition of cadmium is a complex process due to the coexistence of adsorption and nucleation processes; the adsorbed electroactive species appears to be Cd{sup +2}, and a mechanism for cadmium electrodeposition on solid cadmium electrodes is proposed.

  15. The Hera Saturn Entry Probe Mission

    CERN Document Server

    Mousis, O; Spilker, T; Venkatapathy, E; Poncy, J; Frampton, R; Coustenis, A; Reh, K; Lebreton, J -P; Fletcher, L N; Hueso, R; Amato, M J; Colaprete, A; Ferri, F; Stam, D; Wurz, P; Atreya, S; Aslam, S; Banfield, D J; Calcutt, S; Fischer, G; Holland, A; Keller, C; Kessler, E; Leese, M; Levacher, P; Morse, A; Munoz, O; Renard, J -B; Sheridan, S; Schmider, F -X; Snik, F; Waite, J H; Bird, M; Cavalié, T; Deleuil, M; Fortney, J; Gautier, D; Guillot, T; Lunine, J I; Marty, B; Nixon, C; Orton, G S; Sanchez-Lavega, A

    2015-01-01

    The Hera Saturn entry probe mission is proposed as an M--class mission led by ESA with a contribution from NASA. It consists of one atmospheric probe to be sent into the atmosphere of Saturn, and a Carrier-Relay spacecraft. In this concept, the Hera probe is composed of ESA and NASA elements, and the Carrier-Relay Spacecraft is delivered by ESA. The probe is powered by batteries, and the Carrier-Relay Spacecraft is powered by solar panels and batteries. We anticipate two major subsystems to be supplied by the United States, either by direct procurement by ESA or by contribution from NASA: the solar electric power system (including solar arrays and the power management and distribution system), and the probe entry system (including the thermal protection shield and aeroshell). Hera is designed to perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere using a single probe, with the goal of improving our understanding of the origin, formation, and ev...

  16. Doped semiconductor nanocrystal based fluorescent cellular imaging probes.

    Science.gov (United States)

    Maity, Amit Ranjan; Palmal, Sharbari; Basiruddin, S K; Karan, Niladri Sekhar; Sarkar, Suresh; Pradhan, Narayan; Jana, Nikhil R

    2013-06-21

    Doped semiconductor nanocrystals such as Mn doped ZnS, Mn doped ZnSe and Cu doped InZnS, are considered as new classes of fluorescent biological probes with low toxicity. Although the synthesis in high quality of such nanomaterials is now well established, transforming them into functional fluorescent probes remains a challenge. Here we report a fluorescent cellular imaging probe made of high quality doped semiconductor nanocrystals. We have identified two different coating approaches suitable for transforming the as synthesized hydrophobic doped semiconductor nanocrystals into water-soluble functional nanoparticles. Following these approaches we have synthesized TAT-peptide- and folate-functionalized nanoparticles of 10-80 nm hydrodynamic diameter and used them as a fluorescent cell label. The results shows that doped semiconductor nanocrystals can be an attractive alternative for conventional cadmium based quantum dots with low toxicity.

  17. Murine strain differences and the effects of zinc on cadmium concentrations in tissues after acute cadmium exposure

    Energy Technology Data Exchange (ETDEWEB)

    King, L.M. [ARS USDA, Germplasm and Gamete Physiology Lab., Beltsville, MD (United States); Anderson, M.B. [Dept. of Anatomy, Tulane Univ. School of Medicine, New Orleans, LA (United States); Sikka, S.C. [Dept. of Urology, Tulane Univ. School of Medicine, New Orleans, LA (United States); George, W.J. [Dept. of Pharmacology, Tulane Univ. School of Medicine, New Orleans, LA (United States)

    1998-10-01

    The role of strain differences in cadmium tissue distribution was studied using sensitive (129/J) and resistant (A/J) mice. These murine strains have previously been shown to differ in their susceptibility to cadmium-induced testicular toxicity. Cadmium concentration was measured in testis, epididymis, seminal vesicle, liver, and kidney at 24 h after cadmium chloride exposure (4, 10, and 20 {mu}mol/kg CdCl{sub 2}). The 129/J mice exhibited a significant increase in cadmium concentration in testis, epididymis, and seminal vesicle at all cadmium doses used, compared to A/J mice. However, cadmium concentrations in liver and kidney were not different between the strains, at any dose, indicating that cadmium uptake is similar in these organs at 24 h. These murine strains demonstrate similar hepatic and renal cadmium uptake but significantly different cadmium accumulation in the reproductive organs at 24 h. The mechanism of the protective effect of zinc on cadmium toxicity was studied by assessing the impact of zinc acetate (ZnAc) treatment on cadmium concentrations in 129/J mice after 24 h. Zinc pretreatment (250 {mu}mol/kg ZnAc), given 24 h prior to 20 {mu}mol/kg CdCl{sub 2} administration, significantly decreased the amount of cadmium in the testis, epididymis, and seminal vesicle of 129/J mice, and significantly increased the cadmium content of the liver after 24 h. Cadmium levels in the kidney were unaffected at this time. Zinc pretreatment also prevented the cadmium-induced decrease in testicular sperm concentration and epididymal sperm motility seen in 129/J mice. These findings suggest that the differences in the two murine strains may be attributed partly to the differential accumulation of cadmium in murine gonads. This may be caused by strain differences in the specificity of cadmium transport mechanisms. The protective role of zinc in cadmium-induced testicular toxicity in the sensitive strain may be due to an interference in the cadmium uptake by susceptible

  18. Urinary cadmium and estimated dietary cadmium in the Women's Health Initiative.

    Science.gov (United States)

    Quraishi, Sabah M; Adams, Scott V; Shafer, Martin; Meliker, Jaymie R; Li, Wenjun; Luo, Juhua; Neuhouser, Marian L; Newcomb, Polly A

    2016-01-01

    Cadmium, a heavy metal dispersed in the environment as a result of industrial and agricultural applications, has been implicated in several human diseases including renal disease, cancers, and compromised bone health. In the general population, the predominant sources of cadmium exposure are tobacco and diet. Urinary cadmium (uCd) reflects long-term exposure and has been frequently used to assess cadmium exposure in epidemiological studies; estimated dietary intake of cadmium (dCd) has also been used in several studies. The validity of dCd in comparison with uCd is unclear. This study aimed to compare dCd, estimated from food frequency questionnaires, to uCd measured in spot urine samples from 1,002 participants of the Women's Health Initiative. Using linear regression, we found that dCd was not statistically significantly associated with uCd (β=0.006, P-value=0.14). When stratified by smoking status, dCd was not significantly associated with uCd both in never smokers (β=0.006, P-value=0.09) and in ever smokers (β=0.003, P-value=0.67). Our results suggest that because of the lack of association between estimated dCd and measured uCd, dietary estimation of cadmium exposure should be used with caution in epidemiologic studies.

  19. The behaviour of copper isotopes during igneous processes

    Science.gov (United States)

    Savage, P. S.; Moynier, F.; Harvey, J.; Burton, K. W.

    2015-12-01

    Application of Cu isotopes to high temperature systems has recently gained momentum and has the potential for probing sulphide fractionation during planetary differentiation [1]. This requires robust estimates for planetary reservoirs, and a fundamental understanding of how igneous processes affect Cu isotopes; this study aims to tackle the latter. Cogenetic suites affected by both fractionation crystallisation and cumulate formation were analysed to study such effects on Cu isotopes. In S-undersatured systems, Cu behaves incompatibly during melt evolution and the Cu isotope composition of such melt is invariant over the differentiation sequence. In contrast, S-saturated systems show resolvable Cu isotope variations relative to primitive melt. Such variations are minor but imply a slightly heavy Cu isotope composition for continental crust compared to BSE, consistent with granite data [2]. Although olivine accumulation does not affect Cu isotopes, spinel-hosted Cu is isotopically light relative to the bulk. Analysis of variably melt-depleted cratonic peridotites shows that partial melting can affect Cu isotope composition in restite, with the depleted samples isotopically light compared to BSE. This could be due to residual spinel and/or incongruent melting of sulphides - individual sulphides picked from a single xenolith reveal a range of Cu isotope compositions, dependent on composition. Although partial melting may fractionate Cu isotopes, models suggest most mantle-derived melt will have δ65Cu ≈ BSE, as most source Cu will be transferred to the melt. Small degree melts such as ocean island basalts are predicted to be isotopically heavier than MORB, if derived from a primitive mantle source. OIBs have a range of Cu isotope compositions: some are heavier than MORB as predicted; however, some have much lighter compositions. Since Cu isotopes can be significantly fractionated in the surface environment [e.g. 3] OIB Cu isotopic variations may be linked to

  20. RISK ASSESSMENT FOR CADMIUM IN PHOSPHATE FERTILIZERS

    Science.gov (United States)

    Cadmium induced renal tubular dysfunction occurred where subsistence rice farmers produced their lifetime dietary rice on Zn-mine waste contaminated soils in Japan and other Asian countries. Research has shown that polished rice Cd is greatly increased while grain Zn is not incre...

  1. Field scale behaviour of cadmium in soil.

    NARCIS (Netherlands)

    Boekhold, A.E.

    1992-01-01

    Although total heavy metal contents of soil are often used to express the degree of contamination, they are of little value to judge environmental effects. The main objective of this thesis was to develop and test methodologies with which environmental risks of cadmium pollution of field soils can b

  2. Koper, zink en cadmium in voeding

    NARCIS (Netherlands)

    Smolders, E.A.A.

    2003-01-01

    In een tabel is aangegeven hoeveel koper, zink en cadmium een rantsoen gemiddeld moet bevatten om de behoefte van melkvee te dekken. Daarbij is uitgegaan van een gemiddelde benutting. De vraag is of er bij een tekort aangevuld moet worden en of er bij een teveel weggelaten moet worden.

  3. Mobiliteit van cadmium in de bodem

    NARCIS (Netherlands)

    Chardon, W.J.

    1984-01-01

    The adsorption of cadmium by twelve Dutch soils was investigated under widely varying circumstances. The adsorption can be described with the Freundlich equation; the parameters of this equation can be predicted using the properties of the soil (pH, organic carbon and clay content).The adsorption ap

  4. Mobile Game Probes

    DEFF Research Database (Denmark)

    Borup Lynggaard, Aviaja

    2006-01-01

    This paper will examine how probes can be useful for game designers in the preliminary phases of a design process. The work is based upon a case study concerning pervasive mobile phone games where Mobile Game Probes have emerged from the project. The new probes are aimed towards a specific target...... group and the goal is to specify the probes so they will cover the most relevant areas for our project. The Mobile Game Probes generated many interesting results and new issues occurred, since the probes came to be dynamic and favorable for the process in new ways....

  5. Lead and cadmium in breast milk

    Energy Technology Data Exchange (ETDEWEB)

    Sternowsky, H.J.; Wessolowski, R.

    1985-04-01

    Breast milk from 10 women each from the city of Hamburg and from a rural area was analyzed by atomic absorption spectrometry for contamination with lead and cadmium. Samples were examined at regular intervals for 3 months after birth. On day 5 a diurnal profile was analyzed; on the other days milk was taken before and after the morning feed. For breast milk as the main source of nutrition in infants, this study shows values of 9.1 +- 2.5 (SD) ..mu..g/l for lead in the rural population, with a tendency to decrease towards the end of lactation. Urban mothers had 13.3 +- 5.5 (SD) ..mu..g/l, with a tendency to increase. Mean cadmium content in rural mothers was 17.3 +- 4.9 ..mu..g/l, with much higher values in the colostrum and a decrease after 15 days. Urban mothers had 24.6 +- 7.3 ..mu..g/l, again with high colostrum values and a subsequent decrease. Calculated daily intake according to these values is presented, based on 840 ml breast milk for a 5.5 kg infant per day. Rural infants ingested 0.9-1.3 ..mu..g/kg/day of lead, and in the city 1.5-2.3 ..mu..g/kg/day. Cadmium intake in rural infants amounted from 1.2-1.8 ..mu..g/kg/day; in Hamburg it was 1.6-2.2 ..mu..g/kg/day. Thus the daily ingestion of lead was just below the DPI, cadmium ingestion was higher than the DPI for adults. The rural population had lower values in breast milk for both heavy metals than the urban population, although not statistically significant. Compared to earlier reports there was a slight increase in lead concentration and a more significant increase for cadmium.

  6. Cadmium and Chrome Concentrations in Human Milk

    Directory of Open Access Journals (Sweden)

    Sima Nazarpour

    2014-04-01

    Full Text Available Introduction: Nutrition of children has the highest priority in any program aimed at children's health care. Milk contaminated with various toxic elements can have adverse effects on children's health. This study aimed to determine the concentration of heavy metals including cadmium(Cd and chromium (Cr of breast feeding women’s milk in Varamin. Methods: This is a cross sectional study. In the present study, chromium and cadmium levels in milk of 100 mothers attending clinics in the city of Varamin were measured in four to eight weeks after delivery, using atomic absorption spectrometry. Results: The mean values (±SD of Cd and Cr in human milk were 5±6.9 μg/ml and 3±2.7 μg/ml respectively. Result of Linear regression showed that cadmium levels were higher in breast milk of people living close to the factory or industrial center. Also, the chromium levels were higher in the breast milk of women in cases of: Smoking by spouses, consumption of imported rice, consumption of mineral water, and living close to the factory or an industrial center. Conclusion: This study showed that the relationship of some factors such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water, with the level of cadmium and chromium. Cadmium and chromium levels of breast milk in this study were higher than the levels of these elements mentioned in the reviewed articles and international standard. Because some variables, such as living near a factory or an industrial center, smoking by spouse, the type of consumed rice and water can affect the amount of entering elements in breast milk. Actions can be taken to reduce or eliminate these variables in order to decrease the mentioned elements in human milk.

  7. Cadmium phytoextraction potential of different Alyssum species

    Energy Technology Data Exchange (ETDEWEB)

    Barzanti, R., E-mail: rbarzanti@supereva.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Colzi, I., E-mail: ilariacolzi@hotmail.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Arnetoli, M., E-mail: miluscia@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gallo, A., E-mail: galloalessia@hotmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Pignattelli, S., E-mail: sara.pignattelli@gmail.com [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gabbrielli, R., E-mail: gabbrielli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy); Gonnelli, C., E-mail: cristina.gonnelli@unifi.it [Department of Evolutionary Biology, Universita di Firenze, via Micheli 1, 50121 Firenze (Italy)

    2011-11-30

    Highlights: Black-Right-Pointing-Pointer The possibility of using serpentine plants for phytoextraction of Cd was investigated. Black-Right-Pointing-Pointer Variation in Cd tolerance, accumulation and translocation in three Alyssum plants with different phenotypes were found. Black-Right-Pointing-Pointer Alyssum montanum showed higher Cd tolerance and accumulation than the Ni hyperaccumulator Alyssum bertolonii. Black-Right-Pointing-Pointer As for the kinetic parameters of the Cd uptake system, A. montanum presented a low apparent K{sub m} value. Black-Right-Pointing-Pointer The V{sub max} values were not significantly different among the plants. - Abstract: This work was planned for providing useful information about the possibility of using serpentine adapted plants for phytoextraction of cadmium, element scarcely represented in such metalliferous environment. To this aim, we investigated variation in cadmium tolerance, accumulation and translocation in three Alyssum plants with different phenotypes: Alyssum bertolonii, that is a serpentine endemic nickel hyperaccumulator, and two populations of Alyssum montanum, one adapted and one not adapted to serpentine soils. Plants were hydroponically cultivated in presence of increasing concentrations of CdSO{sub 4} for two weeks. For the metal concentration used in the experiments, the three different Alyssum populations showed variation in cadmium tolerance, accumulation and content. The serpentine adapted population of A. montanum showed statistically higher cadmium tolerance and accumulation than A. bertolonii and the population of A. montanum not adapted to serpentine soil thus deserving to be investigated for phytoextraction purposes. Furthermore, as for the kinetic parameters of the cadmium uptake system, A. montanum serpentine population presented a low apparent K{sub m} value, suggesting a high affinity for this metal of its uptake system, whereas the V{sub max} values were not significantly different among the

  8. Uranium isotopes fingerprint biotic reduction

    Science.gov (United States)

    Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J.; Weyer, Stefan; Bernier-Latmani, Rizlan

    2015-01-01

    Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium. PMID:25902522

  9. Modelling of Cadmium Transport in Soil-Crop System

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A model for simulating cadmium transport in a soil-plant system was built using a commercial simu lating program named Powersim on the basis of input-output processes happening in the soil-plant system.Convective and dispersive transport processes of cadmium in soil profile are embedded. Simulations on a daily base have been done up to a total simulating time of 250 years. Results show that applications of sewage sludge and fertilizer at the simulated rates would only cause slight cadmium accumulations in each layer of the soil, and cadmium accumulation would be levelling off, reaching an equilibrium concentrations layer by layer downward after certain time. The time scale to reach an equilibrium concentration varies from 10 years for the top three layers to over 250 years for the bottom layers. Plant cadmium uptake would increase from 52 ug m-2 under initial soil cadmium concentrations to 65 μg m-2 under equilibrium soil cadmium concentrations, which would not exceed the maximum allowable cadmium concentration in wheat grains. Main parameters which influence cadmium accumulation and transport in soil are total cadmium input, rainfall, evaporation, plant uptake and soil properties.

  10. Accumulation of cadmium in livers and kidneys in Greenlanders

    Energy Technology Data Exchange (ETDEWEB)

    Johansen, Poul [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)]. E-mail: poj@dmu.dk; Mulvad, Gert [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Pedersen, Henning Sloth [Primary Health Care Center, DK-3900 Nuuk, Greenland (Denmark); Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Hansen, Jens C. [Centre for Arctic Environmental Medicine, University of Aarhus, Universitetsparken, DK-8000 Aarhus C (Denmark); Riget, Frank [National Environmental Research Institute, Frederiksborgvej 399, DK-4000 Roskilde (Denmark)

    2006-12-15

    In the Arctic, the traditional diet exposes its people to a very high intake of cadmium because it is highly concentrated in the liver and kidneys of commonly eaten marine mammals. In one study in Greenland, the cadmium intake was estimated to 182 {mu}g/day/person in the fall and 346 in the spring. To determine whether the cadmium is accumulated in humans, we analyzed autopsy samples of liver and kidneys from 95 ethnic Greenlanders (aged 19-89) who died from a wide range of causes. The cadmium concentration in liver (overall mean 1.97 {mu}g/g wet wt) appeared to be unrelated to any particular age group, whereas the concentrations in the kidneys peaked in Greenlanders between 40 and 50 years of age (peak concentration 22.3 {mu}g/g wet wt). Despite the high cadmium levels in the typical Greenlander diet, we found that the cadmium concentrations in livers and kidneys were comparable to those reported from Denmark, Sweden, Australia and Great Britain. Furthermore, even though the mean cadmium intake from the diet was estimated to be 13-25 times higher in Greenlanders than in Danes, we found similar cadmium levels in the kidneys of both. Seal livers and kidneys are the main source of cadmium in the diet of Greenlanders, but these tissues are not eaten in Denmark. Thus, our results suggest that the accumulation of cadmium from Greenlander's marine diet is very low.

  11. Hepatoprotective activity of Moringa oleifera against cadmium toxicity in rats

    Directory of Open Access Journals (Sweden)

    Reetu Toppo

    2015-04-01

    Full Text Available Aim: The present investigation has been conducted to evaluate the hepatoprotective activity of Moringa oleifera against cadmium-induced toxicity in rats. Materials and Methods: For this study, 18 Wistar albino rats were taken. Control group, Group I rats were given cadmium chloride @ 200 ppm per kg and Group II rats were treated with M. oleifera extract @ 500 mg/kg along with cadmium chloride @ 200 ppm per kg (daily oral for 28 days. On 29th day, animals were slaughtered and various parameters were determined. Serum biomarkers, oxidative stress parameters, histomorphological examination were carried out with estimation of cadmium concentration in liver tissues. Results: Oral administration of cadmium chloride @ 200 ppm/kg for 28 days resulted in a significant increase in aspartate aminotransferase (AST, alanine transaminase (ALT, alkaline phosphatase (ALP, significant (p≤0.01 increase of lipid peroxidation (LPO and decrease in superoxide dismutase (SOD, and increase in cadmium accumulation in liver. Treatment with M. oleifera @ 500 mg/kg significantly (p<0.01 decreased the elevated ALP, AST, ALT, LPO levels and increase in SOD levels, and as compared to cadmium chloride treated group. However, there was no significant difference in cadmium concentration in liver when compared with cadmium chloride treated group. Conclusion: The study conclude that supplementation of M. oleifera (500 mg/kg, daily oral for 28 days has shown protection against cadmium-induced hepatotoxicity.

  12. Properties of Ultrasound Probes

    OpenAIRE

    Rusina, M.

    2015-01-01

    This work deals with the measurement properties of ultrasound probes. Ultrasound probes and their parameters significantly affect the quality of the final image. In this work there are described the possibility of measuring the spatial resolution, sensitivity of the probe and measuring the length of the dead zone. Ultrasound phantom ATS Multi Purpose Phantom Type 539 was used for measurements.

  13. Discovery of the Cobalt Isotopes

    OpenAIRE

    Szymanski, T.; Thoennessen, M.

    2009-01-01

    Twenty-six cobalt isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  14. Discovery of the Arsenic Isotopes

    CERN Document Server

    Shore, A; Heim, M; Schuh, A; Thoennessen, M

    2009-01-01

    Twenty-nine arsenic isotopes have so far been observed; the discovery of these isotopes is discussed. For each isotope a brief summary of the first refereed publication, including the production and identification method, is presented.

  15. Histopathological changes in relation to cadmium concentration in horse kidneys

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Jonsson, L.; Piscator, M.; Rahnster, B.

    1981-10-01

    Histopathological changes in kidney cortex, as observed by light microscopy, are related to cadmium concentration in kidney cortex from 69 normal Swedish horses. Cadmium concentrations in kidney ranged from 11 to 186 ..mu..g Cd/g wet wt with an average of 60 ..mu..g Cd/g, which is considerably higher than those normally found in humans. The microscopical changes were rated and related to cadmium concentrations in kidneys by dose-response curves. A relationship existed between frequency of morphological changes and cadmium concentration in the renal cortex. There was no obvious relationship between age and frequency of histopathological changes. This indicates that in horse kidneys morphological changes occur at cadmium concentrations which are lower than the tentative critical level for humans of 200 ..mu..g Cd/g. It is concluded that horses constitute a population at risk for environmental cadmium contamination.

  16. Study on electrokinetic remediation of cadmium contaminated soils

    Institute of Scientific and Technical Information of China (English)

    SHI Wen-xin; CUI Chong-wei; YU Shui-li; FENG Wei-ming

    2007-01-01

    Kaolinite from a lead-zinc mining district, which was spiked with cadmium, has been treated by electrokinetics to investigate effects of treatment time and applied voltage gradient. The results showed that the increased test duration had induced a higher removal rate of cadmium. Being treated for 7 days, cadmium was removed from kaolinite dramatically. It was also found that higher removal rate happened when a higher voltage gradient was applied and cadmium accumulated near the cathode because pH increased. Increase of pH near the cathode caused accumulation of cadmium. Moreover, it was observed that cation exchange membrane which was placed between kaolinite and cathode could make pH lower than the initial value and avoid the higher pH near the cathode. As a result, the high concentration accumulation of cadmium near the cathode was avoided.

  17. Assessment and management of risk to wildlife from cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Burger, Joanna [Division of Life Sciences, Environmental and Occupational Health Sciences Institute, Consortium for Risk Evaluation with Stakeholder Participation, Rutgers University, Piscataway, New Jersey, 08854-8082 (United States)], E-mail: burger@biology.rutgers.edu

    2008-01-15

    Cadmium, a nonessential heavy metal that comes from natural and anthropogenic sources, is a teratogen, carcinogen, and a possible mutagen. Assessment of potential risk from cadmium requires understanding environmental exposure, mainly from ingestion, although there is some local exposure through inhalation. Chronic exposure is more problematic than acute exposure for wildlife. There is evidence for bioaccumulation, particularly in freshwater organisms, but evidence for biomagnification up the food chain is inconsistent; in some bird studies, cadmium levels were higher in species that are higher on the food chain than those that are lower. Some freshwater and marine invertebrates are more adversely affected by cadmium exposure than are birds and mammals. There is very little experimental laboratory research on the effects of cadmium in amphibians, birds and reptiles, and almost no data from studies of wildlife in nature. Managing the risk from cadmium to wildlife involves assessment (including ecological risk assessment), biomonitoring, setting benchmarks of effects, regulations and enforcement, and source reduction.

  18. Urinary cadmium and mammographic density in premenopausal women.

    Science.gov (United States)

    Adams, Scott V; Newcomb, Polly A; Shafer, Martin M; Atkinson, Charlotte; Bowles, Erin J Aiello; Newton, Katherine M; Lampe, Johanna W

    2011-08-01

    Mammographic density (MD), a strong marker of breast cancer risk, is influenced by genetic, environmental, and hormonal factors. Cadmium, a persistent and widespread environmental pollutant, has been associated with risk of breast cancer, and laboratory evidence suggests cadmium is a carcinogen in the breast. We investigated the hypothesis that cadmium exposure is associated with higher MD. In a cross-sectional study of MD and urinary cadmium concentration, percentage MD (MD%) and Breast Imaging-Reporting and Data Systems (BI-RADS®) density category were determined from screening mammograms of 190 premenopausal women ages 40-45 years. Women completed a health questionnaire, and the cadmium content of spot urine samples was measured with inductively coupled plasma mass spectrometry and corrected for urine creatinine. Urinary cadmium concentrations are thought to reflect exposure to cadmium during a period of 20-30 years. Multivariable linear regression and logistic regression were used to estimate the strength of association between urinary cadmium and mammographic breast density. Adjusted mean MD% among women in the upper tertile of creatinine-corrected urinary cadmium was 4.6% higher (95% CI: -2.3 to 11.6%) than in women in the lowest cadmium tertile. Each twofold increase in urinary cadmium was associated with higher odds of MD% in the upper tertile (OR: 1.29, 95% CI: 0.82-2.02) or a BI-RADS category rating of "extremely dense" (OR: 1.75, 95% CI: 1.14-2.70). Stronger associations were observed among nulliparous women, and current or former smokers. Exposure to cadmium may be associated with increased breast density in premenopausal women.

  19. Embryotoxicity of stable isotopes and use of stable isotopes in studies of teratogenetic mechanisms

    Energy Technology Data Exchange (ETDEWEB)

    Spielmann, H.; Nau, H.

    1986-07-01

    Experiments on teratogenic effects of stable isotopes from our own and other laboratories are evaluated. In the first series of investigations, the enrichment of the stable isotope /sup 13/C derived from U-/sup 13/C-glucose was studied in mouse embryos at various stages of development, including limb buds in organ culture. Preimplantation mouse embryos incubated in vitro in /sup 13/C-enriched medium for 48 hours showed normal development during subsequent differentiation in vitro and also in vivo after embryo transfer to faster mothers. These embryos were 15% to 20% enriched in /sup 13/C. Administration of U-13-C-glucose to pregnant mice during organogenesis led to an increase of the absolute /sup 13/C content of the embryo for several days after the end of isotope administration, whereas the enrichment in maternal tissue decreased. No alterations of embryonic development were detected due to stable isotope enrichment. Development of cultured mouse limb buds was unaffected by incubation with 82 mol% U-/sup 13/C-glucose as judged from morphologic and biochemical criteria. The second part of the article describes the value of deuterium-labeled drugs as probes into the mechanism of activation of teratogenic metabolites. A comparison of the pharmacokinetics as well as the teratogenicity between cyclophosphamide and some specific deuterium-labeled analogues showed that the isotope effect observed can be related to a particular metabolic pathway crucial for teratogenic activation by this drug.

  20. Chromium isotope variations

    DEFF Research Database (Denmark)

    D'Arcy, Joan Mary

    is incorporated into carbonates. Hence, ancient carbonates can potentially record the Cr isotopic composition (δ53Cr ‰) of seawater in the geological past. Reliable application and interpretation of this proxy requires a detailed knowledge about processes that fractionate Cr on the Earth’s surface...... deposited during the Early Ordovician — a time of known redox instability in ancient oceans – exhibit a significant positive Cr isotope excursion of +0.5‰. This excursion is interpreted as the reductive drawn down of dissolved Cr in seawater in response to the development of a proximal anoxic sink......, and the quantification the Cr isotope composition of major Cr fluxes into and out of ocean. This thesis adds to the current knowledge of the Cr isotope system and is divided into two studies. The focus of the first study was to determine what processes control the Cr isotopic compositionof river water and to quantify...

  1. β—Correction Spectrophotometric Determination of Cadmium with Cadion

    Institute of Scientific and Technical Information of China (English)

    郜洪文

    1995-01-01

    Cadmium has been determined by β-correction spectrophotometry with cadion,p-nitrobenzenediazoaminoaz-obenzone,and a non-ionic surfactant,tuiton X-100.The real absorbance of a Cd-cadion chelate in the colored solution can be accurately determined and the complex-ratio of cadion with Cd(II) has been worked out to be 2.Beer's law is obeyed over the concentration range of 0-0.20mg/1 cadmium and the detec-tion limit for cadmium is only 0.003mg/1.Satisfactory experimental results are presented with respect to the determination of trace cadmium in wastewaters.

  2. INVESTIGATION OF THIN FILM CADMIUM SULFIDE SOLAR CELLS.

    Science.gov (United States)

    SOLAR CELLS , *CADMIUM COMPOUNDS, FILMS, SULFIDES, VAPOR PLATING, VACUUM APPARATUS, SINGLE CRYSTALS, TITANIUM, COPPER COMPOUNDS, CHLORIDES, INDIUM, MOLYBDENUM, SILICON COMPOUNDS, MONOXIDES, SURFACE PROPERTIES, ENERGY CONVERSION.

  3. Phytosynthesis of Cadmium Oxide Nanoparticles from Achillea wilhelmsii Flowers

    Directory of Open Access Journals (Sweden)

    Javad Karimi Andeani

    2013-01-01

    Full Text Available The study here deals with the plant synthesis of cadmium oxide nanoparticles using flowers extract of Achillea wilhelmsii as the reducing agent. The photosynthesis is carried out at room temperature in the laboratory ambience. The aqueous cadmium ions when exposed to flower extract were reduced and resulted in their nanoparticles. The synthesized nanoparticles were characterized using techniques such as scanning electron microscope (SEM, Fourier transform infrared spectroscopy (FTIR, and UV-visible absorption spectroscopy. Stable cadmium oxide nanoparticles were formed by treating aqueous solution of cadmium chloride (CdCl2 with the plant flower extracts as reducing agent.

  4. The Hera Saturn entry probe mission

    Science.gov (United States)

    Mousis, O.; Atkinson, D. H.; Spilker, T.; Venkatapathy, E.; Poncy, J.; Frampton, R.; Coustenis, A.; Reh, K.; Lebreton, J.-P.; Fletcher, L. N.; Hueso, R.; Amato, M. J.; Colaprete, A.; Ferri, F.; Stam, D.; Wurz, P.; Atreya, S.; Aslam, S.; Banfield, D. J.; Calcutt, S.; Fischer, G.; Holland, A.; Keller, C.; Kessler, E.; Leese, M.; Levacher, P.; Morse, A.; Muñoz, O.; Renard, J.-B.; Sheridan, S.; Schmider, F.-X.; Snik, F.; Waite, J. H.; Bird, M.; Cavalié, T.; Deleuil, M.; Fortney, J.; Gautier, D.; Guillot, T.; Lunine, J. I.; Marty, B.; Nixon, C.; Orton, G. S.; Sánchez-Lavega, A.

    2016-10-01

    The Hera Saturn entry probe mission is proposed as an M-class mission led by ESA with a contribution from NASA. It consists of one atmospheric probe to be sent into the atmosphere of Saturn, and a Carrier-Relay spacecraft. In this concept, the Hera probe is composed of ESA and NASA elements, and the Carrier-Relay Spacecraft is delivered by ESA. The probe is powered by batteries, and the Carrier-Relay Spacecraft is powered by solar panels and batteries. We anticipate two major subsystems to be supplied by the United States, either by direct procurement by ESA or by contribution from NASA: the solar electric power system (including solar arrays and the power management and distribution system), and the probe entry system (including the thermal protection shield and aeroshell). Hera is designed to perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere using a single probe, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets. Hera's aim is to probe well into the cloud-forming region of the troposphere, below the region accessible to remote sensing, to the locations where certain cosmogenically abundant species are expected to be well mixed. By leading to an improved understanding of the processes by which giant planets formed, including the composition and properties of the local solar nebula at the time and location of giant planet formation, Hera will extend the legacy of the Galileo and Cassini missions by further addressing the creation, formation, and chemical, dynamical, and thermal evolution of the giant planets, the entire solar system including Earth and the other terrestrial planets, and formation of other planetary systems.

  5. Ellipsometric Analysis of Cadmium Telluride Films’ Structure

    Directory of Open Access Journals (Sweden)

    Anna Evmenova

    2015-01-01

    Full Text Available Ellipsometric analysis of CdTe films grown on Si and CdHgTe substrates at the “hot-wall” epitaxy vacuum setup has been performed. It has been found that ellipsometric data calculation carried out by using a simple one-layer film model leads to radical distortion of optical constants spectra: this fact authenticates the necessity to attract a more complicated model that should include heterogeneity of films. Ellipsometric data calculation within a two-layer film model permitted to conclude that cadmium telluride films have an outer layer that consists of the three-component mixture of CdTe, cavities, and basic matter oxide. Ratio of mixture components depends on the time of deposition, that is, on the film thickness. The inner layer consists of cadmium telluride.

  6. Lead, mercury, and cadmium in breast milk

    OpenAIRE

    Kadriye Yurdakök

    2015-01-01

    Toxic heavy metals are the major source of environmental pollution in this new millennium. Lead, mercury, and cadmium are the most common toxic heavy metals in the environment. There is no known function of these toxic heavy metals in the human body. In females, toxic heavy metals can be accumulated in maternal body before pregnancy and may be transferred to fetus through placenta and later, via breast milk. Lead previously accumulated in maternal bones can be mobilized along with calcium in ...

  7. Mercury Cadmium Selenide for Infrared Detection

    Science.gov (United States)

    2013-06-01

    were grown using elemental mercury (Hg), cadmium (Cd), and selenium (Se) sources. The beam equiva- lent pressure ( BEP ) emanating from all sources was...flux), the BEP measured for the cracker source was found to vary with the cracking zone temperature, tracking with the data found in Ref. 7. This sug...The Se BEP measured for the typical cracking zone temperature of 800 C was found to be close to a factor of two lower than at the typical effusion cell

  8. Bioaugmentation with cadmium-resistant plant growth-promoting rhizobacteria to assist cadmium phytoextraction by Helianthus annuus.

    Science.gov (United States)

    Prapagdee, Benjaphorn; Chanprasert, Maesinee; Mongkolsuk, Skorn

    2013-07-01

    Micrococcus sp. MU1 and Klebsiella sp. BAM1, the cadmium-resistant plant growth-promoting rhizobacteria (PGPR), produce high levels of indole-3-acetic acid (IAA) during the late stationary phase of their growth. The ability of PGPR to promote root elongation, plant growth and cadmium uptake in sunflowers (Helianthus annuus) was evaluated. Both species of bacteria were able to remove cadmium ions from an aqueous solution and enhanced cadmium mobilization in contaminated soil. Micrococcus sp. and Klebsiella sp. use aminocyclopropane carboxylic acid as a nitrogen source to support their growth, and the minimum inhibitory concentrations of cadmium for Micrococcus sp. and Klebsiella sp. were 1000 and 800mM, respectively. These bacteria promoted root elongation in H. annuus seedlings in both the absence and presence of cadmium compared to uninoculated seedlings. Inoculation with these bacteria was found to increase the root lengths of H. annuus that had been planted in cadmium-contaminated soil. An increase in dry weight was observed for H. annuus inoculated with Micrococcus sp. Moreover, Micrococcus sp. enhanced the accumulation of cadmium in the root and leaf of H. annuus compared to untreated plants. The highest cadmium accumulation in the whole plant was observed when the plants were treated with EDTA following the treatment with Micrococcus sp. In addition, the highest translocation of cadmium from root to the above-ground tissues of H. annuus was found after treatment with Klebsiella sp. in the fourth week after planting. Our results show that plant growth and cadmium accumulation in H. annuus was significantly enhanced by cadmium-resistant PGPRs, and these bacterial inoculants are excellent promoters of phytoextraction for the rehabilitation of heavy metal-polluted environments.

  9. Bioavailability of cadmium from linseed and cocoa

    DEFF Research Database (Denmark)

    Hansen, Max; Rasmussen, Rie Romme; Sloth, Jens Jørgen

    2014-01-01

    for the food authorities in order to give correct advises to the population. The aim of this study was to investigate the bioavailability of cadmium from whole linseed, crushed linseed, cocoa and cadmium chloride in rats. An experiment where 40 rats were divided into 4 groups and a control group and dosed...... with whole linseed, crushed linseed, cocoa and CdCl2 for 3 weeks was performed. Linseed or cocoa made up 10% of the feed (by weight) and was added as a replacement for carbohydrate source. The rats were dosed for 3 weeks and the cadmium content in the rats' kidneys was measured by ICPMS as a biomarker...... be measured in the kidney compared to the calculated total intake was as follows: Control 2.0 %, Crushed linseed 0.9 %, whole linseed, 1.5 %, cocoa 0.7 % and CdCl2 4.6 %. Based on this study it could not be concluded that the bioavailability in rats form whole linseed is lower that for crushed linseed...

  10. Occupation, cadmium exposure, and prostate cancer.

    Science.gov (United States)

    Elghany, N A; Schumacher, M C; Slattery, M L; West, D W; Lee, J S

    1990-03-01

    A population-based case-control study was used to investigate associations between prostate cancer and cadmium exposure, longest industry held, and longest occupation held. The study included 358 men with newly diagnosed prostate cancer and 679 control men identified from the Utah population. Occupational exposures to cadmium were ascertained from self-reported data, through several a priori suspect industries and occupations, through an occupation-exposure linkage system, and through dietary food frequency questionnaires. Overall, cadmium exposure appeared to result in a small increased relative risk for prostate cancer, most apparent for aggressive tumors (OR = 1.7, CI = 1.0-3.1 for any occupational exposure, high dietary intake, or smoking cigarettes). Cases were more likely to have worked in the following industries: mining, paper and wood, medicine and science, and entertainment and recreation. Among men younger than 67, cases were also more likely to have worked in the food and tobacco industries (OR = 3.6, CI = 1.0-12.8). Cases were less likely to have worked in industries involved with glass, clay and stone, or rubber, plastics, and synthetics. Men employed as janitors and in other building service occupations showed increased relative risk for aggressive tumors (OR = 7.0, CI = 2.5-19.6). Agricultural occupations did not appear to be related to prostate cancer, although an increased relative risk for aggressive tumors was detected among younger men (OR = 2.6, CI = 0.6-12.1).

  11. Soil ecotoxicity assessment using cadmium sensitive plants

    Energy Technology Data Exchange (ETDEWEB)

    An, Youn-Joo

    2004-01-01

    The crop plants, sorghum and cucumber, can be used as indicator species to assess ecotoxicity of soils contaminated by cadmium. - Four crop plant species (sweet corn, Zea may; wheat, Triticum aestivum; cucumber, Cucumis sativus; and sorghum, Sorghum bicolor) were tested to assess an ecotoxicity in cadmium-amended soils. The measurement endpoints used were seed germination and seedling growth (shoot and root). The presence of cadmium decreased the seedling growth. The medium effective concentration values (EC50) for shoot or root growth were calculated by the Trimmed Spearman-Karber method. Due to the greater accumulation of Cd to the roots, root growth was a more sensitive endpoint than shoot growth. Bioavailability and transport of Cd within plant were related to concentration and species. The ratio of bioaccumulation factor (BAF) in the shoots to the roots indicated high immobilization of Cd in the roots. Seed germination was insensitive to Cd toxicity, and is not recommended for a suitable assay. Among the test plants and test endpoints, root growth of sorghum and cucumber appears to be a good protocol to assess ecotoxicity of soils contaminated by Cd.

  12. Environmental cadmium and breast cancer risk.

    Science.gov (United States)

    Gallagher, Carolyn M; Chen, John J; Kovach, John S

    2010-11-01

    Breast cancer is the most prevalent women's cancer, with an age-adjusted incidence of 122.9 per 100,000 US women. Cadmium, a ubiquitous carcinogenic pollutant with multiple biological effects, has been reported to be associated with breast cancer in one US regional case-control study. We examined the association of breast cancer with urinary cadmium (UCd), in a case-control sample of women living on Long Island (LI), NY (100 with breast cancer and 98 without), a region with an especially high rate of breast cancer (142.7 per 100,000 in Suffolk County) and in a representative sample of US women (NHANES 1999-2008, 92 with breast cancer and 2,884 without). In a multivariable logistic model, both samples showed a significant trend for increased odds of breast cancer across increasing UCd quartiles (NHANES, p=0.039 and LI, p=0.023). Compared to those in the lowest quartile, LI women in the highest quartile had increased risk for breast cancer (OR=2.69; 95% CI=1.07, 6.78) and US women in the two highest quartiles had increased risk (OR=2.50; 95% CI=1.11, 5.63 and OR=2.22; 95% CI=.89, 5.52, respectively). Further research is warranted on the impact of environmental cadmium on breast cancer risk in specific populations and on identifying the underlying molecular mechanisms.

  13. Influence of a high level of dietary cadmium on cadmium content in milk, excretion, and cow performance

    Energy Technology Data Exchange (ETDEWEB)

    Miller, W.J.; Lampp, B.; Powell, G.W.; Salotti, C.A.; Blackmon, D.M.

    1967-01-01

    Three Holstein cows were each given 3.0 g of cadmium daily (two equal doses) for two weeks by gelatin capsules. There was a sharp drop in concentrate consumption for the first few days of cadmium administration but, by the second week, consumption returned to normal. Milk production declined sharply for several days and then increased appreciably, but to a level still substantially lower than that of controls during the last five days cadmium was given. When cadmium treatments ceased, milk production increased by 50%. Fat content of milk was elevated considerably during the week when production was most reduced. Cows given cadmium lost considerable weight. There were no other clinical manifestations of toxicity. As determined by the chromic oxide indicator method and twice-daily grab samples, fecal excretion of cadmium for the second week averaged 82% of that given. The cadmium level in the urine was below the limits of detectability of the method (0.5 ppm of urine). The cadmium content of the milk was less than 0.1 ppm of the milk, which was the lower reliability limit of the procedure used. On this basis less than 0.22% of the amount administered appeared in the milk. In vitro studies demonstrated that cadmium combines with the casein and whey protein fractions of the milk readily, with the amount combined being linear when levels from 1.0 to 25.0 ppm are added to milk. Smaller amounts were present in the lactose and mineral fractions.

  14. Probing the water interactions in clay

    Energy Technology Data Exchange (ETDEWEB)

    Powell, D.H. [Lausanne Univ., Lausanne (Switzerland); Fischer, H.E. [Institut Max von Laue - Paul Langevin (ILL), 38 - Grenoble (France); Skipper, N.T. [Univ. College, London (United Kingdom)

    1999-11-01

    Clays, the microscopic mineral fraction of soils, are probably the most important substrate for interactions between water, the mineral world and the biosphere. A knowledge of the structuring of water and hydrated metal ions near clays surfaces is of importance in environmental science, including toxic and radioactive waste disposal, and in the industrial application of clays. The smectite clays, with their large hydrated internal surface areas represent excellent model systems for the interactions of aqueous phases with solid surface. We present the results of neutron diffraction experiments using isotopic substitutions to probe the structure in the aqueous interlayer region of Li-montmorillonite. (authors) 6 refs., 3 figs.

  15. Correlative characteristic of cadmium in soils of steppe Dnieper region

    Directory of Open Access Journals (Sweden)

    N. M. Tsvetkova

    2015-09-01

    Full Text Available Much attention is paid to searching for methods of establishing environmental standards for objective assessment of admissibility of anthropogenic load on the biosphere. The main pollutants of the environment are xenobiotics; heavy metals such as cadmium occupy hold a special place among them. Cadmium is one of the most dangerous environmental toxic agents, belonging to the 1stclass of hazard. Due to insufficient and fragmented information available on the distribution of cadmium in the city edaphotopes, it’s necessary to conduct additional research, taking into account the properties of soils and the biological characteristics of every element. The paper shows the ratio of cadmium in soils and soil-forming rocks of steppe Dnieper region. Environmental assessment of cadmium content in Dniprodzerzhinsk city soilsis made, and the problem of topsoil contamination of the city as a territory of high anthropogenic load is considered. It is found that the content of cadmium down the profile in natural soil increases. Enrichment of the topsoil with cadmium occurs due to contamination. The value of movable forms content, expressed as a percentage of the total content, varies from 12% to 70%, providing the evidence of the technogenic origin of cadmium in Dniprodzerzhinsk city topsoil. General and proximate correlation analyses of interrelation of soil cadmium and specifically selected characteristics of soil (pH, humus, sulfate ions, dry solid, chloride ions, total alkalinity, hygroscopic moisture were made. It is established that cadmium concentration in the movable forms of natural soils of the steppe Dnieper region depends primarily on pH value. With the increase in pH value, concentration of movable cadmium in soil increases.

  16. Cadmium induces transcription independently of intracellular calcium mobilization.

    Directory of Open Access Journals (Sweden)

    Brooke E Tvermoes

    Full Text Available BACKGROUND: Exposure to cadmium is associated with human pathologies and altered gene expression. The molecular mechanisms by which cadmium affects transcription remain unclear. It has been proposed that cadmium activates transcription by altering intracellular calcium concentration ([Ca(2+](i and disrupting calcium-mediated intracellular signaling processes. This hypothesis is based on several studies that may be technically problematic; including the use of BAPTA chelators, BAPTA-based fluorescent sensors, and cytotoxic concentrations of metal. METHODOLOGY/PRINCIPAL FINDING: In the present report, the effects of cadmium on [Ca(2+](i under non-cytotoxic and cytotoxic conditions was monitored using the protein-based calcium sensor yellow cameleon (YC3.60, which was stably expressed in HEK293 cells. In HEK293 constitutively expressing YC3.60, this calcium sensor was found to be insensitive to cadmium. Exposing HEK293::YC3.60 cells to non-cytotoxic cadmium concentrations was sufficient to induce transcription of cadmium-responsive genes but did not affect [Ca(2+](i mobilization or increase steady-state mRNA levels of calcium-responsive genes. In contrast, exposure to cytotoxic concentrations of cadmium significantly reduced intracellular calcium stores and altered calcium-responsive gene expression. CONCLUSIONS/SIGNIFICANCE: These data indicate that at low levels, cadmium induces transcription independently of intracellular calcium mobilization. The results also support a model whereby cytotoxic levels of cadmium activate calcium-responsive transcription as a general response to metal-induced intracellular damage and not via a specific mechanism. Thus, the modulation of intracellular calcium may not be a primary mechanism by which cadmium regulates transcription.

  17. Experiments and Monte Carlo modeling of a higher resolution Cadmium Zinc Telluride detector for safeguards applications

    Science.gov (United States)

    Borella, Alessandro

    2016-09-01

    The Belgian Nuclear Research Centre is engaged in R&D activity in the field of Non Destructive Analysis on nuclear materials, with focus on spent fuel characterization. A 500 mm3 Cadmium Zinc Telluride (CZT) with enhanced resolution was recently purchased. With a full width at half maximum of 1.3% at 662 keV, the detector is very promising in view of its use for applications such as determination of uranium enrichment and plutonium isotopic composition, as well as measurement on spent fuel. In this paper, I report about the work done with such a detector in terms of its characterization. The detector energy calibration, peak shape and efficiency were determined from experimental data. The data included measurements with calibrated sources, both in a bare and in a shielded environment. In addition, Monte Carlo calculations with the MCNPX code were carried out and benchmarked with experiments.

  18. Cadmium Depletion Impacts on Hardening Neutron6 Spectrum for Advanced Fuel Testing in ATR

    Energy Technology Data Exchange (ETDEWEB)

    Gray S. Chang

    2011-05-01

    For transmuting long-lived isotopes contained in spent nuclear fuel into shorter-lived fission products effectively is in a fast neutron spectrum reactor. In the absence of a fast spectrum test reactor in the United States of America (USA), initial irradiation testing of candidate fuels can be performed in a thermal test reactor that has been modified to produce a test region with a hardened neutron spectrum. A test region is achieved with a Cadmium (Cd) filter which can harden the neutron spectrum to a spectrum similar (although still somewhat softer) to that of the liquid metal fast breeder reactor (LMFBR). A fuel test loop with a Cd-filter has been installed within the East Flux Trap (EFT) of the Advanced Test Reactor (ATR) at the Idaho National Laboratory (INL). A detailed comparison analyses between the cadmium (Cd) filter hardened neutron spectrum in the ATR and the LMFBR fast neutron spectrum have been performed using MCWO. MCWO is a set of scripting tools that are used to couple the Monte Carlo transport code MCNP with the isotope depletion and buildup code ORIGEN-2.2. The MCWO-calculated results indicate that the Cd-filter can effectively flatten the Rim-Effect and reduce the linear heat rate (LHGR) to meet the advanced fuel testing project requirements at the beginning of irradiation (BOI). However, the filtering characteristics of Cd as a strong absorber quickly depletes over time, and the Cd-filter must be replaced for every two typical operating cycles within the EFT of the ATR. The designed Cd-filter can effectively depress the LHGR in experimental fuels and harden the neutron spectrum enough to adequately flatten the Rim Effect in the test region.

  19. Cadmium in the environment: a toxicological and epidemiological appraisal

    Energy Technology Data Exchange (ETDEWEB)

    Friberg, L.; Piscator, M.; Nordberg, G.

    1971-01-01

    This book is a review of the toxicity of cadmium, and has focused on information considered important for understanding the toxic action of cadmium on animals and man. Dose-response relationships are discussed as are effects on specific organ systems and modes of uptake.

  20. Cadmium Removal from Aqueous Solutions by Ground Pine Cone

    Directory of Open Access Journals (Sweden)

    H Izanloo, S Nasseri

    2005-01-01

    Full Text Available A study on the removal of cadmium ions from aqueous solutions by pine cone was conducted in batch conditions. Kinetic data and equilibrium removal isotherms were obtained. The influence of different experimental parameters such as contact time, initial concentration of cadmium, pine cone mass and particle size, and temperature on the kinetics of cadmium removal was studied. Results showed that the main parameters that played an important role in removal phenomenon were initial cadmium concentration, particle size and pine cone mass. The necessary time to reach equilibrium was between 4 and 7 hours based on the initial concentration of cadmium. The capacity of cadmium adsorption at equilibrium increased with the decrease of pine cone particle size. The capacity of cadmium adsorption at equilibrium by pine cone increased with the quantity of pine cone introduced (1–4 g/L. Temperature in the range of 20-30°C showed a restricted effect on the removal kinetics (13.56 mg/g at 20°C and a low capacity of adsorption about 11.48 mg/g at 30°C. The process followed pseudo second-order kinetics. The cadmium uptake of pine cone was quantitatively evaluated using adsorption isotherms. Results indicated that the Langmuir model gave a better fit to the experimental data in comparison with the Freundlich equation.

  1. Drikkevands optagelse af cadmium og bly fra armaturer

    DEFF Research Database (Denmark)

    Nielsen, K.

    Notatet omfatter rapporter fra to forsøgsrækker vedr. brugsvands optagelse af bly og cadmium. Den første omhandler brugsvandsarmaturers afgivelse af bly og cadmium til syntetisk brugsvand med en sammensætning svarende til en sur, blød vandtype. Forsøgene omfatter 10 armaturer og armaturdele...

  2. Removing cadmium from electroplating wastewater by waste saccharomyces cerevisiae

    Institute of Scientific and Technical Information of China (English)

    DAI Shu-juan; WEI De-zhou; ZHOU Dong-qin; JIA Chun-yun; WANG Yu-juan; LIU Wen-gang

    2008-01-01

    The appropriate condition and scheme of removing cadmium from electroplating wastewater were investigated by adsorption-precipitation method using waste saccharomyces cerevisiae(WSC) as sorbent. Effect factors on biosorption of cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae and precipitation process of waste saccharomyces cerevisiae after adsorbing cadmium were studied. The results show that removal rate of cadmium is over 88% after 30 min adsorbing under the condition of cadmium concentration 26 mg/L, the dosage of waste saccharomyces cerevisiae 16.25 g/L, temperature 18 ℃, pH 6.0 and precipitation time 4 h. Biosorption-precipitation method is effective to remove cadmium in cadmium-containing electroplating wastewater by waste saccharomyces cerevisiae. The SEM, infrared spectroscopy and Zeta-potential of the cells show that chemical chelating is the main adsorption form; electrostatic attraction, hydrogen bonding and van der Waals force all function in adsorption process; and ―NH2―,―C=O―,―C=O―NH―,―CH3, ―OH are the main adsorption groups.

  3. Cadmium and zinc reversibly arrest development of Artemia larvae

    Energy Technology Data Exchange (ETDEWEB)

    Bagshaw, J.C.; Rafiee, P.; Matthews, C.O.; MacRae, T.H.

    1986-08-01

    Despite the widespread distribution of heavy metals such as cadmium and zinc in the environment and their well-known cytotoxicity and embryotoxicity in mammals, comparatively little is known about their effect on aquatic organisms, particularly invertebrates. Post-gastrula and early larval development of the brine shrimp, Artemia, present some useful advantages for studies of developmental aspects of environmental toxicology. Dormant encysted gastrulae, erroneously called brine shrimp eggs, can be obtained commercially and raised in the laboratory under completely defined conditions. Following a period of post-gastrula development within the cyst, pre-nauplius larvae emerge through a crack in the cyst shell. A few hours later, free-swimming nauplius larvae hatch. Cadmium is acutely toxic to both adults and nauplius larvae of Artemia, but the reported LC50s are as high as 10 mM, depending on larval age. In this paper the authors show that pre-nauplius larvae prior to hatching are much more sensitive to cadmium than are hatched nauplius larvae. At 0.1 ..mu..m, cadmium retards development and hatching of larvae; higher concentrations block hatching almost completely and thus are lethal. However, the larvae arrested at the emergence stage survive for 24 hours or more before succumbing to the effects of cadmium, and during this period the potentially lethal effect is reversible if the larvae are placed in cadmium-free medium. The effects of zinc parallel those of cadmium, although zinc is somewhat less toxic than cadmium at equal concentrations.

  4. Epigenetic Effects of Cadmium [Abstract and Poster 2014

    Science.gov (United States)

    We have reviewed the literature on in vitro and in vivo experiments as well as human studies on cadmium to understand the epigenetic mechanisms involved in cadmium- induced toxicity and carcinogenicity. This presentation will identify gaps in our current understanding and suggest...

  5. Cadmium inhibits neurogenesis in zebrafish embryonic brain development

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Elly Suk Hen [Division of Biology, California Institute of Technology, 1200 California Boulevard, Pasadena, CA 91125 (United States); Hui, Michelle Nga Yu; Lin Chunchi [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China); Cheng Shukhan [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, Hong Kong (China)], E-mail: bhcheng@cityu.edu.hk

    2008-05-01

    Cadmium is a non-essential heavy metal found abundantly in the environment. Children of women exposed to cadmium during pregnancy display lower motor and perceptual abilities. High cadmium body burden in children is also related to impaired intelligence and lowered school achievement. However, little is known about the molecular and cellular basis of developmental neurotoxicity in the sensitive early life stages of animals. In this study, we explore neurological deficits caused by cadmium during early embryonic stages in zebrafish by examining regionalization of the neural tube, pattern formation and cell fate determination, commitment of proneural genes and induction of neurogenesis. We show that cadmium-treated embryos developed a smaller head with unclear boundaries between the brain subdivisions, particularly in the mid-hindbrain region. Embryos display normal anterior to posterior regionalization; however, the commitment of neural progenitor cells was affected by cadmium. We observe prominent reductions in the expression of several proneuronal genes including ngn1 in cell clusters, zash1a in the developing optic tectum, and zash1b in the telencephalon and tectum. Cadmium-treated embryos also have fewer differentiated neurons and glia in the facial sensory ganglia as indicated by decreased zn-12 expression. Also, a lower transcription level of neurogenic genes, ngn1 and neuroD, is observed in neurons. Our data suggest that cadmium-induced neurotoxicity can be caused by impaired neurogenesis, resulting in markedly reduced neuronal differentiation and axonogenesis.

  6. Cadmium-induced ectopic apoptosis in zebrafish embryos

    Energy Technology Data Exchange (ETDEWEB)

    Chan, Po Kwok; Cheng, Shuk Han [Department of Biology and Chemistry, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon (Hong Kong)

    2003-02-01

    In this study, we tested the hypothesis that cadmium-induced developmental toxicity was mediated via ectopic occurrence of apoptosis during embryonic development. We employed confocal microscopy to acquire images of whole-mount staining of apoptotic cells in zebrafish embryo exposed to 100 {mu}M cadmium from 5 hours post fertilisation (hpf) to 28 hpf. Three-dimensional reconstruction of the images was performed and the spatial and temporal distributions of apoptotic cells in the embryos were compared. In cadmium-treated embryos with varying degrees of gross developmental malformations, significantly higher numbers of apoptotic cells were detected with this method. In order to detect the precise locations of apoptotic cells, we performed terminal deoxynucleotidyl transferase-mediated dUTP nick end labelling (TUNEL) assay in sectioned embryos. In the degenerating neural tube of cadmium-treated embryos apoptotic cells were detected, while in the healthy neural tube of the untreated controls no apoptotic cells were found. We then employed flow cytometry to investigate whether cadmium exposure would affect the dynamics of apoptosis or induce any abnormalities in cell-cycle progression. It appeared that cadmium did not induce cell-cycle arrest. The percentages of apoptotic cells did not differ in the two groups at 13, 16 or 19 hpf. At 28 hpf, however, a significantly higher percentage of apoptotic cells were found in the cadmium-treated group. Exposure to cadmium, therefore, induced ectopic apoptosis at 28 hpf without affecting the dynamics of apoptosis at earlier developmental stages. (orig.)

  7. Risk of overestimation of urinary cadmium concentrations: interference from molybdenum

    Directory of Open Access Journals (Sweden)

    Cañas A.I.

    2013-04-01

    Full Text Available We show here that the selection of analytical method is critical when measuring low levels of cadmium in human urine. Cadmium is today usually analyzed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS, which has a higher sensitivity than Atomic Absorption Spectroscopy (AAS. ICP-MS cadmium measurements show interference from tin (114Sn and molybdenum oxides, which can result in an overestimation of cadmium levels. The 114Sn interference is stable and can be mathematically corrected. Molybdenum concentrations in urine are variable and different from individual to individual. We have estimated the degree of error which molybdenum interference introduces in the measurement of cadmium in urine by conventional ICP-MS. 268 urine samples from mothers and their children were measured. Removal of the molybdenum oxide interference (DRC-ICP-MS method reduced urinary cadmium concentrations significantly (47.8%. The urinary molybdenum concentration in children was higher than in their mothers, resulting in greater overestimation. Our results clearly show that the DRC method is essential for reliable measurements of urinary cadmium concentrations, particularly in children. Furthermore, care should be taken when comparing Human Biomonitoring data for cadmium in urine and attention should be paid to which analytical method has been used (e.g. AAS and ICP-Ms, and especially if the measurements have been corrected for molybdenum interference.

  8. Perchlorate isotope forensics

    Science.gov (United States)

    Böhlke, J.K.; Sturchio, N.C.; Gu, B.; Horita, J.; Brown, G.M.; Jackson, W.A.; Batista, J.; Hatzinger, P.B.

    2005-01-01

    Perchlorate has been detected recently in a variety of soils, waters, plants, and food products at levels that may be detrimental to human health. These discoveries have generated considerable interest in perchlorate source identification. In this study, comprehensive stable isotope analyses ( 37Cl/35Cl and 18O/17O/ 16O) of perchlorate from known synthetic and natural sources reveal systematic differences in isotopic characteristics that are related to the formation mechanisms. In addition, isotopic analyses of perchlorate extracted from groundwater and surface water demonstrate the feasibility of identifying perchlorate sources in contaminated environments on the basis of this technique. Both natural and synthetic sources of perchlorate have been identified in water samples from some perchlorate occurrences in the United States by the isotopic method. ?? 2005 American Chemical Society.

  9. Isotope Production Facility (IPF)

    Data.gov (United States)

    Federal Laboratory Consortium — The Los Alamos National Laboratory has produced radioactive isotopes for medicine and research since the mid 1970s, when targets were first irradiated using the 800...

  10. Calcium stable isotope geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Gausonne, Nikolaus [Muenster Univ. (Germany). Inst. fuer Mineralogie; Schmitt, Anne-Desiree [Strasbourg Univ. (France). LHyGeS/EOST; Heuser, Alexander [Bonn Univ. (Germany). Steinmann-Inst. fuer Geologie, Mineralogie und Palaeontologie; Wombacher, Frank [Koeln Univ. (Germany). Inst. fuer Geologie und Mineralogie; Dietzel, Martin [Technische Univ. Graz (Austria). Inst. fuer Angewandte Geowissenschaften; Tipper, Edward [Cambridge Univ. (United Kingdom). Dept. of Earth Sciences; Schiller, Martin [Copenhagen Univ. (Denmark). Natural History Museum of Denmark

    2016-08-01

    This book provides an overview of the fundamentals and reference values for Ca stable isotope research, as well as current analytical methodologies including detailed instructions for sample preparation and isotope analysis. As such, it introduces readers to the different fields of application, including low-temperature mineral precipitation and biomineralisation, Earth surface processes and global cycling, high-temperature processes and cosmochemistry, and lastly human studies and biomedical applications. The current state of the art in these major areas is discussed, and open questions and possible future directions are identified. In terms of its depth and coverage, the current work extends and complements the previous reviews of Ca stable isotope geochemistry, addressing the needs of graduate students and advanced researchers who want to familiarize themselves with Ca stable isotope research.

  11. Isotopes in Greenland Precipitation

    DEFF Research Database (Denmark)

    Faber, Anne-Katrine

    the Arctic Ocean. A comprehensive database is created based on ice core and weather station data from Greenland within the period 1890-2014. Present day annual and seasonal mean values are computed for 326 locations in Greenland. Parameterization of the spatial distribution of temperature and δ18O are used...... of model and data can be used to improve the understanding of climate changes. This is done through analysis of isotope modelling, observations and ice core measurements. This dissertation comprises three projects: (1) Modelling the isotopic response to changes in Arctic sea surface conditions, (2......) Constructing a new Greenland database of observations and present-day ice core measurements, and (3) Performance test of isotope-enabled CAM5 for Greenland. The recent decades of rapid Arctic sea ice decline are used as a basis for an observational-based model experiment using the isotope-enabled CAM model 3...

  12. Isotopically controlled semiconductors

    Energy Technology Data Exchange (ETDEWEB)

    Haller, E.E.

    2004-11-15

    A review of recent research involving isotopically controlled semiconductors is presented. Studies with isotopically enriched semiconductor structures experienced a dramatic expansion at the end of the Cold War when significant quantities of enriched isotopes of elements forming semiconductors became available for worldwide collaborations. Isotopes of an element differ in nuclear mass, may have different nuclear spins and undergo different nuclear reactions. Among the latter, the capture of thermal neutrons which can lead to neutron transmutation doping, can be considered the most important one for semiconductors. Experimental and theoretical research exploiting the differences in all the properties has been conducted and will be illustrated with selected examples. Manuel Cardona, the longtime editor-in-chief of Solid State Communications has been and continues to be one of the major contributors to this field of solid state physics and it is a great pleasure to dedicate this review to him.

  13. $\\beta$-delayed neutron spectroscopy of $^{130-132}$ Cd isotopes with the ISOLDE decay station and the VANDLE array

    CERN Multimedia

    We propose to use the new ISOLDE decay station and the neutron detector VANDLE to measure the $\\beta$-delayed neutron emission of N=82-84 $^{130-132}$Cd isotopes. The large delayed neutron emission probability observed in a previous ISOLDE measurement is indicative of the Gamow-Teller transitions due to the decay of deep core neutrons. Core Gamow-Teller decay has been experimentally proven in the $^{78}$Ni region for the N>50 nuclei using the VANDLE array. The spectroscopic measurement of delayed neutron emission along the cadmium isotopic chain will allow us to track the evolution of the single particle states and the shell gap.

  14. Isotopes through the looking glass

    Science.gov (United States)

    Mårtensson Pendrill, Ann Marie

    2000-08-01

    Nuclear distributions affect many aspects of atomic spectra. As an example, recent experimental results for the hyperfine anomaly in Fr isotopes are considered. These depend on nuclear charge and magnetization distributions. The variations in charge radii for these isotopes were studied earlier by measuring optical isotope shifts. The hyperfine anomalies for the odd-odd isotopes involve the neutron distributions, of interest for studies of parity nonconserving effects along a chain of isotopes.

  15. Cadmium chronic administration to lactating ewes. Reproductive performance, cadmium tissue accumulation and placental transfer

    Energy Technology Data Exchange (ETDEWEB)

    Floris, B.; Bomboi, G.; Sechi, P.; Marongiu, M. L. [Sassari Univ., Sassari (Italy). Dipt. di Biologia Animale; Pirino, S. [Sassari Univ., Sassari (Italy). Ist. di Patologia Generale, Anatomia Patologica e Clinica Ostetrico-chirurgica Veterinaria

    2000-12-01

    20 lactating ewes were allotted to two groups: 10 subjects received orally 100 mg/day of CdCl{sub 2} for 108 consecutive days, and the remaining 10 acted as control. Reproductive performance in ewes and cadmium tissue accumulation, both in ewes and their lambs, were investigated. The results showed that in ewes: 1) the regular cadmium intestinal intake negatively influences all reproductive parameters; 2) cadmium is particularly accumulated in kidney and liver, bur also in mammary gland, although at distinctly lower level; 3) chronic administration does not increase cadmium placental transfer in lactating pregnant subjects. [Italian] 20 pecore in lattazione sono state suddivise in 2 gruppi: 10 soggetti ricevettero per os 100 mg/giorno di CdCl{sub 2} per 108 giorni consecutivi, e i restanti 10 funsero da controllo. Sono stati studiati i parametri riproduttivi delle pecore e l'accumulo di cadmio nei tessuti, sia delle pecore che dei loro agnelli. I risultati hanno mostrato che negli ovini: 1) il regolare assorbimento intestinale di cadmio influenza negativamente tutti i parametri riproduttivi; 2) il cadmio viene accumulato principalmente nei reni e nel fegato, ma anche dalla ghiandola mammaria, sebbene in misura nettamente inferiore; 3) la somministrazione cronica di cadmio nei soggetti gravidi non incrementa il suo passaggio transplacentare.

  16. The effect of phosphate fertilizer cadmium on cadmium in soils and crops

    NARCIS (Netherlands)

    Smilde, K.W.; Luit, van B.

    1983-01-01

    Een van de oorzaken, waardoor bodemvervuiling met cadmium optreedt en dus een bevordering van cadmiumopname door het gewas, is toepassing van fosfaatkunstmest, waarin zich verschillende gehaltes van dit zware metaal bevinden. Dit rapport behandelt het onderzoek naar de stijging van het cadmiumgehalt

  17. SORPTION OF CADMIUM ONTO DIFFERENT FRACTIONS OF BIOSOLIDS AND CADMIUM SALT AMENDED SOILS

    Science.gov (United States)

    Biosolids and Cd salt-amended soils were collected from a long-term field experiment established in 1976. Cadmium sorption experiments were conducted on different fractions of soils amended with biosolids, Cd salt, and unamended soils (control). The organic carbon (OC) of soils ...

  18. Comparison of toxicity and disposition of cadmium chloride and cadmium metallothionein in rats.

    NARCIS (Netherlands)

    Groten, J.P.

    1992-01-01

    In Chapter 1 of this thesis a general introduction is presented with a survey of the literature. It gives a brief overview of the factors involved in the absorption, metabolism and toxicity of Cd after oral intake.In short, the main source of environmental exposure to cadmium for no

  19. Methods of isotopic geochronology

    Science.gov (United States)

    Gorokhov, I. M.; Levchenkov, O. A.

    Papers are presented on such topics as the age of the chemical elements; the age of meteorites, the moon, and the earth; isotopic ages of the most ancient terrestrial formations; and the Archean evolution of Enderby Land in the Antarctic as evidenced by isotopic dating. Consideration is also given to a uranium-lead geochronology technique for investigating Precambrian ore deposits, a Pb-Pb technique of zircon dating, and the potentials and limitations of Sm-Nd geochronology.

  20. High-resolution laser spectroscopy of nickel isotopes

    CERN Multimedia

    This proposal aims to measure the nuclear ground-state spins, moments and mean-square charge radii of $^{56-71}$Ni using collinear laser spectroscopy. This will enable direct measurements of isotopes in the region of shell closure $^{56}$Ni, structural change $^{68}$Ni and monopole migration beyond N = 40. Optical spectroscopy serves as a detailed probe not only of the changing single-particle behaviour, but also for the study of collective properties such as size and shape. Measurements of the most neutron-rich isotopes available at ISOLDE will critically test models which seek to extrapolate the data to the doubly magic region of $^{78}$Ni.

  1. Serum beta2-microglobulin in cadmium exposed workers.

    Science.gov (United States)

    Piscator, M

    1978-09-01

    In cadmium exposed workers with renal tubular dysfunction the determination of beta2m in urine is an important diagnostic test. Cadmium exposure's influence on serum beta2m levels and its relationship to urinary excretion of beta2m were studied in 24 cadmium exposed workers with normal serum creatinine levels (less than 10 mg/l)) and no obvious tubular dysfunction. With increasing blood levels of cadmium beta2m was found to increase in serum. There was no concomitant increase in the urinary excretion of beta2m. Serum beta2m was not dependent on serum creatinine within the range studied. The results suggest that for evaluating renal glomerular function in cadmium exposed workers, it might be better to use the serum creatinine level, creatinine clearance or inulin clearance since beta2m might give some false positive results.

  2. Determination of the cadmium and copper content inherent to metallothionein

    Energy Technology Data Exchange (ETDEWEB)

    Raspor, B.; Kozar, S.; Pavicic, J.; Juric, D. [Ruder Boskovic Institute, Center for Marine Research Zagreb, P.O.B. 1016, HR-10 001 Zagreb (Croatia)

    1998-05-01

    The reliability of the voltammetric determination of the cadmium and copper content (at pH 1.0), inherent to metallothionein (MT) isolated from the digestive gland of Mytilus galloprovincialis, was investigated. An artifact signal enhancement of copper, caused by the cupric-thionein complex adsorption at the mercury electrode, was established. This artifact was removed by UV-digestion of the sample for 15-20 h prior to analysis. A similar artifact was not detected for cadmium, because at this pH the cadmium-thionein complex has dissociated, and cadmium exists in the ionic form. Therefore, the voltammetric analysis of the cadmium content can be performed directly at pH 1.0, without prior UV-digestion of the sample. (orig.) With 3 figs., 1 tab., 12 refs.

  3. Effect of pregnancy on cadmium-treated rats

    Energy Technology Data Exchange (ETDEWEB)

    Takizama, Y. (Akita Univ. School of Medicine, Japan); Nakamura, I.; Kurayama, R.; Hirasawa, F.; Kawai, K.

    1982-01-01

    It is well known that itai-itai disease with the osteopathy is broken out among multiparas, 40 years of age and up Japanese residents. In this paper we described an experimental study of effect of pregnancy on cadmium treated rats. Female mature rats were administered drinking water containing 50 and 200 ppm cadmium as CdCl/sub 2/. During 180 days of the experiment, three times of pregnancy were succesful, though slight depression of body weight gain was noticed in the 200 ppm group. The cadmium was accumulated in the kidneys, liver and bone proportionally to the amount of cadmium administered. No significant change was recognized in serum calcium, phosphorus and alkaline phosphatase levels after 180 days. Though cadmium 200 ppm treated rats showed slight histological lesions in the proximal convoluted tubules of the kidney, there appeared to be no osteomalacia including excess formation of osteoid tissue.

  4. Synthesis of cadmium chalcogenide nanotubes at room temperature

    KAUST Repository

    Pan, Jun

    2012-10-01

    Cadmium chalcogenide (CdE, E=S, Se, Te) polycrystalline nanotubes have been synthesized from precursor of CdS/cadmium thiolate complex at room temperature. The precursor was hydrothermally synthesized at 180 °C using thioglycolic acid (TGA) and cadmium acetate as starting materials. The transformation from the rod-like precursor of CdS/cadmium thiolate complex to CdS, CdSe and CdTe nanotubes were performed under constant stirring at room temperature in aqueous solution containing S 2-, Se 2- and Te 2-, respectively. The nanotube diameter can be controlled from 150 to 400 nm related to the dimension of templates. The XRD patterns show the cadmium chalcogenide nanotubes all corresponding to face-centered cubic structure. © 2012 Elsevier B.V. All rights reserved.

  5. Chronic cadmium poisoning in a pigment manufacturing plant

    Energy Technology Data Exchange (ETDEWEB)

    De Silva, P.E.; Donnan, M.B.

    1981-02-01

    When the working environment in a small cadmium-pigment manufacturing plant was investigated, cadmium concentrations in respirable dust were found to be considerably above the hygiene standard recommended by the British Occupational Hygiene Society. Cadmium concentrations in blood and urine of exposed workers, both present and past employees, were determined. The six men who had worked in the production plant for seven years or more all showed signs of renal tubular damage. On the basis of the results of the investigations on individuals in this study, it is suggested that urinary cadmium concentrations should be kept below 15 microgram/day to avoid the possibility of renal damage, and that the insoluble respirable fraction of cadmium dust should not be regarded as merely nuisance dust.

  6. Adsorption of cadmium from aqueous solutions by perlite.

    Science.gov (United States)

    Mathialagan, T; Viraraghavan, T

    2002-10-14

    The present study examined the use of perlite for the removal of cadmium from aqueous solutions. The effects of pH and contact time on the adsorption process were examined. The optimum pH for adsorption was found to be 6.0. Residual cadmium concentration reached equilibrium in 6h and the rate of cadmium adsorption by perlite was rapid in the first hour of the reaction time. Ho's pseudo-second-order model best described the kinetics of the reaction. Batch adsorption experiments conducted at room temperature (22+/-1 degrees C) showed that the adsorption pattern followed the Freundlich isotherm model. The maximum removal of cadmium obtained from batch studies was 55%. Thomas model was used to describe the adsorption data from column studies. The results generally showed that perlite could be considered as a potential adsorbent for cadmium removal from aqueous solutions.

  7. Cadmium adsorption in montmorillonite as affected by glyphosate

    Institute of Scientific and Technical Information of China (English)

    WANG Yu-jun; ZHOU Dong-mei; LUO Xiao-san; SUN Rui-juan; CHEN Huai-man

    2004-01-01

    Behaviors of soil heavy metals are often affected by coexisting herbicides due to their physical and chemical interaction. Effect of glyphosate, an herbicide containing -PO32- and -COOH groups, on cadmium adsorption in montmorillonite was studied in detail. The results showed that cadmium adsorption quantity in montmorillonite increased with increasing soil solution pH and cadmium concentration as usual, but decreased with glyphosate, which is due to the formation of a low affinity complex of Cd and glyphosate and decreasing solution pH induced by glyphosate addition. When the equilibrium solution pH was below 6.7, glyphosate has little effect on cadmium adsorption, but when the equilibrium solution pH was above 6.7, glyphosate significantly decreased cadmium adsorption quantity in montmorillonite. In addition, the adding order of Cd and glyphosate also influenced Cd adsorption quantity in montmorillonite.

  8. Oxygen Isotopes in Meteorites

    Science.gov (United States)

    Clayton, R. N.

    2003-12-01

    Oxygen isotope abundance variations in meteorites are very useful in elucidating chemical and physical processes that occurred during the formation of the solar system (Clayton, 1993). On Earth, the mean abundances of the three stable isotopes are 16O: 99.76%, 17O: 0.039%, and 18O: 0.202%. It is conventional to express variations in abundances of the isotopes in terms of isotopic ratios, relative to an arbitrary standard, called SMOW (for standard mean ocean water), as follows:The isotopic composition of any sample can then be represented by one point on a "three-isotope plot," a graph of δ17O versus δ18O. It will be seen that such plots are invaluable in interpreting meteoritic data. Figure 1 shows schematically the effect of various processes on an initial composition at the center of the diagram. Almost all terrestrial materials lie along a "fractionation" trend; most meteoritic materials lie near a line of "16O addition" (or subtraction). (4K)Figure 1. Schematic representation of various isotopic processes shown on an oxygen three-isotope plot. Almost all terrestrial materials plot along a line of "fractionation"; most primitive meteoritic materials plot near a line of "16O addition." The three isotopes of oxygen are produced by nucleosynthesis in stars, but by different nuclear processes in different stellar environments. The principal isotope, 16O, is a primary isotope (capable of being produced from hydrogen and helium alone), formed in massive stars (>10 solar masses), and ejected by supernova explosions. The two rare isotopes are secondary nuclei (produced in stars from nuclei formed in an earlier generation of stars), with 17O coming primarily from low- and intermediate-mass stars (shielding in the UV photodissociation of CO (van Dishoeck and Black, 1988). This process results from the large differences in abundance between C16O, on the one hand, and C17O and C18O on the other. Photolysis of CO occurs by absorption of stellar UV radiation in the

  9. Essential roles of Cdc42 and MAPK in cadmium-induced apoptosis in Litopenaeus vannamei

    Energy Technology Data Exchange (ETDEWEB)

    Peng, Ting; Wang, Wei-Na, E-mail: weina63@aliyun.com; Gu, Mei-Mei; Xie, Chen-Ying; Xiao, Yu-Chao; Liu, Yuan; Wang, Lei

    2015-06-15

    Highlights: • Cd{sup 2+} induces Cdc42 and MAPKs pathway related gene of Litopenaeus vannamei up-regulation. • Reduction of THC, increase of ROS production and apoptotic cell rate were observed when the shrimps exposure to Cd{sup 2+}. • DsRNA-suppression of LvCdc42 and MAPKs during Cd{sup 2+} stress reduces the ROS production and apoptosis. • We conclude that LvCdc42 and MAPKs play key roles in Cd{sup 2+} stress responses of shrimps. - Abstract: Cadmium, one of the most toxic heavy metals in aquatic environments, has severe effects on marine invertebrates and fishes. The MAPK signaling pathway plays a vital role in stress responses of animals. The mitogen-activated protein kinase (MAPK) signaling pathway plays a vital role in animals’ stress responses, including mediation of apoptosis induced by the Rho GTPase Cdc42. However, there is limited knowledge about its function in shrimps, although disorders exacerbated by environmental stresses (including heavy metal pollution) have caused serious mortality in commercially cultured shrimps. Thus, we probed roles of Cdc42 in Litopenaeus vannamei shrimps (LvCdc42) during cadmium exposure by inhibiting its expression using dsRNA-mediated RNA interference. The treatment successfully reduced expression levels of MAPKs (including p38, JNK, and ERK). Cadmium exposure induced significant increases in expression levels of LvCdc42 and MAPKs, accompanied by reductions in total hemocyte counts (THC) and increases in apoptotic hemocyte ratios and ROS production. However, all of these responses were much weaker in LvCdc42-suppressed shrimps, in which mortality rates were higher than in controls. Our results suggest that the MAPK pathway plays a vital role in shrimps’ responses to Cd{sup 2+}. They also indicate that LvCdc42 in shrimps participates in its regulation, and thus plays key roles in ROS production, regulation of apoptosis and associated stress responses.

  10. Collinear laser spectroscopy on radioactive praseodymium ions and cadmium ions; Kollineare Laserspektroskopie an radioaktiven Praseodymionen und Cadmiumatomen

    Energy Technology Data Exchange (ETDEWEB)

    Froemmgen, Nadja

    2013-11-21

    Collinear laser spectroscopy is a tool for the model independent determination of spins, charge radii and electromagnetic moments of nuclei in ground and long-lived isomeric states. In the context of this thesis a new offline ion source for high evaporating temperatures and an ion beam analysis system were implemented at the TRIGA-LASER Experiment at the Institute for Nuclear Chemistry at the University of Mainz. The main part of the thesis deals with the determination of the properties of radioactive praseodymium and cadmium isotopes by collinear laser spectroscopy at ISOLDE/CERN. The necessary test measurements for the spectroscopy of praseodymium ions have been conducted with the aforementioned offline ion source at the TRIGA-LASER experiment. The spectroscopy of the praseodymium ions was motivated by the observation of a modulation of the electron capture decay rates of hydrogen-like {sup 140}Pr{sup 58+}. The nuclear magnetic moment of the nucleus is, among others, required for the explanation of the so-called GSI Oscillations and has not been studied experimentally before. Additionally, the determined electron capture decay constant of hydrogen-like {sup 140}Pr{sup 58+} is lower than the one of helium-like {sup 140}Pr{sup 57+}. The explanation of this phenomenon requires a positive magnetic moment. During the experiment at the COLLAPS apparatus the magnetic moments of the neutron-deficient isotopes {sup 135}Pr, {sup 136}Pr and {sup 137}Pr could be determined for the first time. Unfortunately, due to a too low production yield the desired isotope {sup 140}Pr could not be studied.The systematic study of cadmium isotopes was motivated by nuclear physics in the tin region. With Z=48 two protons are missing for the shell closure and the isotopes extend from the magic neutron number N=50 to the magic neutron number N=82. The extracted nuclear properties allow tests of different nuclear models in this region. In this thesis the obtained results of the spectroscopy of

  11. Pulmonary and gastrointestinal exposure to cadmium oxide dust in a battery factory

    Energy Technology Data Exchange (ETDEWEB)

    Adamsson, E.; Piscator, M.; Nogawa, K.

    1979-02-01

    The elimination of cadmium in feces was studied in a group of 15 male workers exposed to cadmium oxide dust in a nickel-cadmium battery factory. The elimination of cadmium in feces was on the average 619 and 268 microgram/day in seven smokers and eight nonsmokers, respectively. The cadmium concentrations in blood were significantly higher in smokers than in nonsmokers, both before and after one month of vacation. Among the smokers there was a significant decrease in the cadmium concentrations during the vacation period, but not among the nonsmokers. It was estimated that cadmium naturally occurring in food and cigarettes, cadmium excreted from the gastrointestinal tract, and cadmium transported from the lungs by mucocillary clearance to the gastrointestinal tract only could explain up to 100 microgram of the cadmium in the feces.

  12. Sources of cadmium exposure among healthy premenopausal women

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Scott V., E-mail: sadams@fhcrc.org [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Newcomb, Polly A. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Shafer, Martin M. [Environmental Chemistry and Technology Program, University of Wisconsin and Wisconsin State Laboratory of Hygiene, Madison, WI (United States); Atkinson, Charlotte [Department of Oral and Dental Science, Bristol Dental School, Bristol (United Kingdom); Bowles, Erin J. Aiello [Group Health Research Institute, Seattle, WA (United States); Newton, Katherine M. [Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States); Group Health Research Institute, Seattle, WA (United States); Lampe, Johanna W. [Fred Hutchinson Cancer Research Center, PO Box 19024, M4-B402, Seattle, WA 98109 (United States); Department of Epidemiology, University of Washington, Box 357236, Seattle, WA 98195 (United States)

    2011-04-01

    Background: Cadmium, a persistent and widespread environmental pollutant, has been associated with kidney function impairment and several diseases. Cigarettes are the dominant source of cadmium exposure among smokers; the primary source of cadmium in non-smokers is food. We investigated sources of cadmium exposure in a sample of healthy women. Methods: In a cross-sectional study, 191 premenopausal women completed a health questionnaire and a food frequency questionnaire. The cadmium content of spot urine samples was measured with inductively-coupled plasma mass spectrometry and normalized to urine creatinine content. Multivariable linear regression was used to estimate the strength of association between smoking habits and, among non-smokers, usual foods consumed and urinary cadmium, adjusted for age, race, multivitamin and supplement use, education, estimated total energy intake, and parity. Results: Geometric mean urine creatinine-normalized cadmium concentration (uCd) of women with any history of cigarette smoking was 0.43 {mu}g/g (95% confidence interval (CI): 0.38-0.48 {mu}g/g) and 0.30 {mu}g/g (0.27-0.33 {mu}g/g) among never-smokers, and increased with pack-years of smoking. Analysis of dietary data among women with no reported history of smoking suggested that regular consumption of eggs, hot cereals, organ meats, tofu, vegetable soups, leafy greens, green salad, and yams was associated with uCd. Consumption of tofu products showed the most robust association with uCd; each weekly serving of tofu was associated with a 22% (95% CI: 11-33%) increase in uCd. Thus, uCd was estimated to be 0.11 {mu}g/g (95% CI: 0.06-0.15 {mu}g/g) higher among women who consumed any tofu than among those who consumed none. Conclusions: Cigarette smoking is likely the most important source of cadmium exposure among smokers. Among non-smokers, consumption of specific foods, notably tofu, is associated with increased urine cadmium concentration. - Research highlights: {yields

  13. Pioneer Jupiter orbiter probe mission 1980, probe description

    Science.gov (United States)

    Defrees, R. E.

    1974-01-01

    The adaptation of the Saturn-Uranus Atmospheric Entry Probe (SUAEP) to a Jupiter entry probe is summarized. This report is extracted from a comprehensive study of Jovian missions, atmospheric model definitions and probe subsystem alternatives.

  14. Cadmium, Mercury and Lead in Hypericum perforatum L. collected in Western Serbia

    Directory of Open Access Journals (Sweden)

    Đurović D.

    2013-04-01

    Full Text Available Wild population of Hypericum perforatum growing in Western Serbia was analyzed for the content of important environmental pollutants cadmium, mercury and lead. Metal contents were determined by inductively coupled plasma optical emission spectrometry. Obtained results showed that levels of mercury and lead were under while cadmium concentrations exceeded limits recommended for medicinal plants. High levels of cadmium in investigated plants can be the result of soil enriched with cadmium as well as the ability of Hypericum perforatum to accumulate cadmium.

  15. Pulmonary and gastrointestinal exposure to cadmium oxide dust in a battery factory.

    Science.gov (United States)

    Adamsson, E; Piscator, M; Nogawa, K

    1979-02-01

    The elimination of cadmium in feces was studied in a group of 15 male workers exposed to cadmium oxide dust in a nickel-cadmium battery factory. The elimination of cadmium in feces was on the average 619 and 268 microgram/day in seven smokers and eight nonsmokers, respectively. The corresponding ranges were 97-2577 and 31-1102 microgram/day. The cadmium concentrations in blood were significantly higher in smokers than in nonsmokers, both before and after one month of vacation. Among the smokers there was a significant decrease in the cadmium concentrations during the vacation period, but not among the nonsmokers. It was estimated that cadmium naturally occurring in food and cigarettes, cadmium excreted from the gastrointestinal tract, and cadmium transported from the lungs by mucocillary clearance to the gastrointestinal tract only could explain up to 100 microgram of the cadmium in the feces. Since even among some nonsmokers much higher values for fecal cadmium were recorded, this was interpreted as being the result of ingestion of cadmium from contaminated hands and other body surfaces. Among the smokers, direct oral contact with contaminated cigarettes or pipes is an additional factor; the smokers also inhale cadmium in the tobacco smoke from contaminated cigarettes. Part of that cadmium is transferred to the gastrointestinal tract by mucociliary clearance and also adds to the fecal cadmium.

  16. Blood cadmium concentration and lipid profile in Korean adults

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kisok, E-mail: kimkisok@kmu.ac.kr [Department of Public Health, Keimyung University, 1000 Shindang-dong, Daegu 704-701 (Korea, Republic of)

    2012-01-15

    Although animal experiments have shown that cadmium exposure induces alterations in lipid profiles, no epidemiological study of this relationship has been performed. The objective of this study was to evaluate the association between blood cadmium concentration and blood lipid levels in Korean adults. A cross-sectional study comprising participants (n=3903) aged 20 years or older from the 2005, 2008, and 2009 Korea National Health and Nutrition Examination Surveys was conducted. Demographic characteristics and dietary intake were obtained from the participants by questionnaire, and cadmium and lipid levels were determined by analysis of blood samples. After adjusting for demographic and dietary factors, blood concentration of cadmium was positively associated with the risk of low high-density lipoprotein cholesterol (HDL-C) in a dose-dependent manner (p for trend <0.001). In addition, the odds ratios (ORs) of a high triglyceride to HDL-C ratio was significantly increased in the high blood cadmium groups [OR=1.36; 95% confidence interval (CI), 1.03-1.79 for fourth quintile and OR=1.41; 95% CI, 1.07-1.86 for fifth quintile] compared with the lowest quintile group. However, high blood cadmium was not associated with a risk of high total cholesterol, high low-density lipoprotein cholesterol, or high triglycerides. These data suggest that an increased cadmium body burden increases the risk of dyslipidemia, mainly due to the increased risk of low HDL-C and the high ratio of triglycerides to HDL-C.

  17. Protective effect of cannabidiol against cadmium hepatotoxicity in rats.

    Science.gov (United States)

    Fouad, Amr A; Al-Mulhim, Abdulruhman S; Gomaa, Wafaey

    2013-10-01

    The protective effect of cannabidiol, the non-psychoactive component of Cannabis sativa, against liver toxicity induced by a single dose of cadmium chloride (6.5 mgkg(-1) i.p.) was investigated in rats. Cannabidiol treatment (5 mgkg(-1)/day, i.p.) was applied for five days starting three days before cadmium administration. Cannabidiol significantly reduced serum alanine aminotransferase, and suppressed hepatic lipid peroxidation, prevented the depletion of reduced glutathione and nitric oxide, and catalase activity, and attenuated the elevation of cadmium level in the liver tissue resulted from cadmium administration. Histopathological examination showed that cadmium-induced liver tissue injury was ameliorated by cannabidiol treatment. Immunohistochemical analysis revealed that cannabidiol significantly decreased the cadmium-induced expression of tumor necrosis factor-α, cyclooxygenase-2, nuclear factor-κB, caspase-3, and caspase-9, and increased the expression of endothelial nitric oxide synthase in liver tissue. It was concluded that cannabidiol may represent a potential option to protect the liver tissue from the detrimental effects of cadmium toxicity.

  18. Accumulation and distribution of arsenic and cadmium by tea plants

    Institute of Scientific and Technical Information of China (English)

    Yuan-zhi SHI; Jian-yun RUAN; Lifeng MA; Wen-yan HAN; Fang WANG

    2008-01-01

    It is important to research the rules about accumulation and distribution of arsenic and cadmium by tea plants, which will give us some scientific ideas about how to control the contents of arsenic and cadmium in tea. In this study, by field inves- tigation and pot trial, we found that mobility of arsenic and cadmium in tea plants was low. Most arsenic and cadmium absorbed were fixed in feeding roots and only small amount was transported to the above-ground parts. Distribution of arsenic and cadmium, based on their concentrations of unit dry matter, in tea plants grown on un-contaminated soil was in the order: feeding roots>stems≈main roots>old leaves>young leaves. When tea plants were grown on polluted soils simulated by adding salts of these two metals, feeding roots possibly acted as a buffer and defense, and arsenic and cadmium were transported less to the above- ground parts. The concentration of cadmium in soil significantly and negatively correlated with chlorophyll content, photosyn- thetic rate, transpiration rate and biomass production of tea plants.

  19. Gadolinium chloride pretreatment ameliorates acute cadmium-induced hepatotoxicity.

    Science.gov (United States)

    Kyriakou, Loukas G; Tzirogiannis, Konstantinos N; Demonakou, Maria D; Kourentzi, Kalliopi T; Mykoniatis, Michael G; Panoutsopoulos, Georgios I

    2013-08-01

    Cadmium is a known industrial and environmental pollutant. It causes hepatotoxicity upon acute administration. Features of cadmium-induced acute hepatoxicity encompass necrosis, apoptosis, peliosis and inflammatory infiltration. Gadolinium chloride (GdCl3) may prevent cadmium-induced hepatotoxicity by suppressing Kupffer cells. The effect of GdCl3 pretreatment on a model of acute cadmium-induced liver injury was investigated. Male Wistar rats 4-5 months old were injected intraperitoneally with normal saline followed by cadmium chloride (CdCl2; 6.5 mg/kg) or GdCl3 (10 mg/kg) followed by CdCl2 (6.5 mg/kg; groups I and II, respectively). Rats of both the groups were killed at 9, 12, 16, 24, 48 and 60 h after cadmium intoxication. Liver sections were analyzed for necrosis, apoptosis, peliosis and mitoses. Liver regeneration was also evaluated by tritiated thymidine incorporation into hepatic DNA. Serum levels of aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were also determined. Hepatic necrosis, hepatocyte and nonparenchymal cell apoptosis and macroscopic and microscopic types of peliosis hepatis were minimized by gadolinium pretreatment. Serum levels of AST and ALT were also greatly diminished in rats of group II. Tritiated thymidine incorporation into hepatic DNA was increased in gadolinium pretreatment rats. Kupffer cell activation was minimal in both the groups of rats. Gadolinium pretreatment attenuates acute cadmium-induced liver injury in young Wistar rats, with mechanisms other than Kupffer cell elimination.

  20. The role of lead and cadmium in psychiatry

    Directory of Open Access Journals (Sweden)

    Orish Ebere Orisakwe

    2014-01-01

    Full Text Available Psychiatric disorders are associated with long-term disability and huge social and economic costs. The possible influence of heavy metals exposure on public health remains a matter of concern. A recurring research question that persisted among researchers in neuropsychiatry has been "are psychiatric patients more likely to have a high body burden of lead or other heavy metals?" This is an update account on the role of lead and cadmium in psychiatry. This review, which has employed search words like "lead and cadmium in psychiatry" , "lead and cadmium in schizophrenia", "lead and cadmium in psychosis" in citation indices such as PubMed, Google Scholar, Scirus, and Scopus. A total of 415 articles were found; 60 fulfiled the inclusion criteria. Evidence-based information suggests that lead and cadmium may be involved in psychiatry. Should environmental lead and cadmium be implicated in the etiogenesis of psychiatry given the characteristic high environmental pollution in Sub Sahara Africa, it is worthwhile for toxicologists and scientists in Sub-Sahara Africa to investigate if lead and cadmium can become additional biomarkers in the diagnosis of psychiatric disorders.

  1. Cadmium determination in Lentinus edodes mushroom species

    Directory of Open Access Journals (Sweden)

    Vera Akiko Maihara

    2012-09-01

    Full Text Available Many studies have drawn attention to the occurrence and concentration of toxic elements found in the fruiting body of mushrooms. Some edible mushroom species are known to accumulate high levels of inorganic contaminants, mainly cadmium, mercury, and lead. There are about 2,000 known edible mushroom species, but only 25 of them are cultivated and used as food. In Brazil, the most marketed and consumed mushroom species are Agaricus bisporus, known as Paris champignon, Lentinus edodes, or Shitake and Pleurotus sp, also called Shimeji or Hiratake. In this study, the concentration of cadmium was determined in Lentinus edodes mushrooms from different cities in São Paulo state and some samples imported from Japan and China. The analyses were performed by graphite furnace atomic absorption spectrometry after HNO3-H2O2 digestion. The results showed a lower concentration of Cd in the mushrooms cultivated in São Paulo (0.0079 to 0.023 mg.kg-1 in natura than that of the mushrooms cultivated abroad (0.125 to 0.212 mg.kg-1 in natura. Although there is no tolerance limit for Cd in mushrooms in Brazil, the results show that Lentinus edodes mushrooms can be safely consumed.

  2. Cadmium minimization in wheat: A critical review.

    Science.gov (United States)

    Rizwan, Muhammad; Ali, Shafaqat; Abbas, Tahir; Zia-Ur-Rehman, Muhammad; Hannan, Fakhir; Keller, Catherine; Al-Wabel, Mohammad I; Ok, Yong Sik

    2016-08-01

    Cadmium (Cd) accumulation in wheat (Triticum aestivum L.) and its subsequent transfer to food chain is a major environmental issue worldwide. Understanding wheat response to Cd stress and its management for aiming to reduce Cd uptake and accumulation in wheat may help to improve wheat growth and grain quality. This paper reviewed the toxic effects, tolerance mechanisms, and management of Cd stress in wheat. It was concluded that Cd decreased germination, growth, mineral nutrients, photosynthesis and grain yield of wheat and plant response to Cd toxicity varies with cultivars, growth conditions and duration of stress applied. Cadmium caused oxidative stress and genotoxicity in wheat plants. Stimulation of antioxidant defense system, osmoregulation, ion homeostasis and over production of signalling molecules are important adaptive strategies of wheat under Cd stress. Exogenous application of plant growth regulators, inorganic amendments, proper fertilization, silicon, and organic, manures and biochar, amendments are commonly used for the reduction of Cd uptake in wheat. Selection of low Cd-accumulating wheat cultivars, crop rotation, soil type, and exogenous application of microbes are among the other agronomic practices successfully employed in reducing Cd uptake by wheat. These management practices could enhance wheat tolerance to Cd stress and reduce the transfer of Cd to the food chain. However, their long-term sustainability in reducing Cd uptake by wheat needs further assessment.

  3. Isotope geochemistry. Biological signatures in clumped isotopes of O₂.

    Science.gov (United States)

    Yeung, Laurence Y; Ash, Jeanine L; Young, Edward D

    2015-04-24

    The abundances of molecules containing more than one rare isotope have been applied broadly to determine formation temperatures of natural materials. These applications of "clumped" isotopes rely on the assumption that isotope-exchange equilibrium is reached, or at least approached, during the formation of those materials. In a closed-system terrarium experiment, we demonstrate that biological oxygen (O2) cycling drives the clumped-isotope composition of O2 away from isotopic equilibrium. Our model of the system suggests that unique biological signatures are present in clumped isotopes of O2—and not formation temperatures. Photosynthetic O2 is depleted in (18)O(18)O and (17)O(18)O relative to a stochastic distribution of isotopes, unlike at equilibrium, where heavy-isotope pairs are enriched. Similar signatures may be widespread in nature, offering new tracers of biological and geochemical cycling.

  4. Cadmium in organs and tissues of horses slaughtered in Italy.

    Science.gov (United States)

    Baldini, M; Stacchini, P; Cubadda, F; Miniero, R; Parodi, P; Facelli, P

    2000-08-01

    The cadmium content of muscle, liver, kidney and blood samples from 62 horses slaughtered in Italy was investigated. Cadmium was determined by graphite furnace atomic absorption spectrometry (GFAAS) after wet digestion of the samples. The mean and median contents of all samples were (on a fresh weight basis) 75 and 41 micrograms kg-1 for muscle, 2.46 and 2.10 mg kg-1 for liver, 20.0 and 13.5 mg kg-1 for kidney. The cadmium level in blood samples was always below 6 micrograms l-1. The cadmium concentrations in muscle, liver and kidney were found to be related to the life span of the specimens and increased with age. Females exhibited higher levels than males, but this difference was significant only in the case of muscle tissue. The geographical origin was recognized as the main factor influencing the cadmium content of the equine specimens analysed. The differences between horses coming from the three main breeding countries considered in this study (Poland, Lithuania, Hungary) were marked and statistically significant. The average intake of cadmium from equine meat was estimated for the general population and for population groups resident in areas with high consumption of this food item. While the cadmium intake from equine meat for the average consumer accounts for about 1% of the total cadmium intake estimated for Italy, in the latter case the enhanced consumption of equine muscle is often accompanied with the consumption of substantial quantities of equine liver and this may lead to high cadmium intakes.

  5. Stable isotopes. Applications and production; Les isotopes stables. Applications - production

    Energy Technology Data Exchange (ETDEWEB)

    Goldstein, S.; Louvet, P.; Soulie, E. [eds.

    1994-12-31

    This conference presents 46 communications concerning stable isotope production, utilization and application, grouped in 6 sessions and posters. The various themes are: biological applications (pharmacology, medical diagnosis, metabolism and protein studies, toxicity and response studies, labelled compounds), analysis procedures (NMR analysis for macromolecules, tracer studies), nuclear applications (utilization of stable isotopes in nuclear reactors), biological, physical and chemical applications (mass transfer, mobility, crystallography, isotopic exchange), stable isotope production (ion chromatography, ion cyclotron resonance, cryogenic distillation).

  6. Deformation of C isotopes

    CERN Document Server

    Kanada-Enyo, Y

    2004-01-01

    Systematic analysis of the deformations of proton and neutron densities in even-even C isotopes was done based on the method of antisymmetrized molecular dynamics. The $E2$ transition strength was discussed in relation to the deformation. We analyze the $B(E2;2^+_1\\to 0^+_1)$ in $^{16}$C, which has been recently measured to be abnormally small. The results suggest the difference of the deformations between proton and neutron densities in the neutron-rich C isotopes. It was found that stable proton structure in C isotopes plays an important role in the enhancement the neutron skin structure as well as in the systematics of $B(E2)$ in the neutron-rich C.

  7. Exposure dose response relationships of the freshwater bivalve Hyridella australis to cadmium spiked sediments

    Energy Technology Data Exchange (ETDEWEB)

    Marasinghe Wadige, Chamani P.M., E-mail: chamani.marasinghe.wadige@canberra.edu.au; Maher, William A.; Taylor, Anne M.; Krikowa, Frank

    2014-07-01

    Highlights: • The exposure–dose–response approach was used to assess cadmium exposure and toxicity. • Accumulated cadmium in H. australis reflected the sediment cadmium exposure. • Spill over of cadmium into the biologically active pool was observed. • Increased cadmium resulted in measurable biological effects. • H. australis has the potential to be a cadmium biomonitor in freshwater environments. - Abstract: To understand how benthic biota may respond to the additive or antagonistic effects of metal mixtures in the environment it is first necessary to examine their responses to the individual metals. In this context, laboratory controlled single metal-spiked sediment toxicity tests are useful to assess this. The exposure–dose–response relationships of Hyridella australis to cadmium-spiked sediments were, therefore, investigated in laboratory microcosms. H. australis was exposed to individual cadmium spiked sediments (<0.05 (control), 4 ± 0.3 (low) and 15 ± 1 (high) μg/g dry mass) for 28 days. Dose was measured as cadmium accumulation in whole soft body and individual tissues at weekly intervals over the exposure period. Dose was further examined as sub-cellular localisation of cadmium in hepatopancreas tissues. The biological responses in terms of enzymatic and cellular biomarkers were measured in hepatopancreas tissues at day 28. H. australis accumulated cadmium from spiked sediments with an 8-fold (low exposure organisms) and 16-fold (high exposure organisms) increase at day 28 compared to control organisms. The accumulated tissue cadmium concentrations reflected the sediment cadmium exposure at day 28. Cadmium accumulation in high exposure organisms was inversely related to the tissue calcium concentrations. Gills of H. australis showed significantly higher cadmium accumulation than the other tissues. Accumulated cadmium in biologically active and biologically detoxified metal pools was not significantly different in cadmium exposed

  8. Electrodialytic removal of cadmium from straw combustion fly ash

    DEFF Research Database (Denmark)

    Hansen, Henrik K.; Ottosen, Lisbeth M.; Villumsen, Arne

    2004-01-01

    Fly ash from straw combustion contains valuable nutrients when returned to agricultural soils. In many instances, however, this fly ash may contain heavy metals, such as cadmium, at levels which often exceed the limits given by the Danish legislation. Thus before utilizing the nutrients, cadmium...... must be removed from these ashes. The use of an electrodialytic remediation method to remove cadmium from fly ash arising from straw combustion and containing 11.2 mg Cd kg$+-1$/ DM (dry matter) was accessed. After 36 days of remediation at a constant current density of 5.6 mA cm$+-2$/ more than 97...

  9. Cadmium and zinc concentrations in fetal and maternal rat tissues after parenteral administration of cadmium during pregnancy

    Energy Technology Data Exchange (ETDEWEB)

    Hazelhoff Roelfzema, W.; Roelofsen, A.M.; Herber, R.F.M.; Copius Peereboom-Stegeman, J.H.J.

    1988-10-01

    Cadmium (Cd) and zinc (Zn) concentrations were determined by solid sampling atomic absorption spectrometry (AAS) in rat maternal and fetal tissues after exposure to cadmium. Cadmium was administered subcutaneously as CdCl/sub 2/ in saline daily during pregnancy. Two experiments were performed. In expt. I we investigated the tissue concentration at day 19 (gestational age) after addministration of several doses: 0, 1.1, 2.2, 4.4, and 8.8 ..mu..mol Cd/kg/day. In expt. II the course of the Cd and Zn concentrations during pregnancy was investigated by collecting samples at days 14, 16, 18 and 20, after daily injections of 4.4 ..mu..mol Cd/kg. Cadmium concentrations in blood, maternal liver, placenta and fetal liver increased with dose and duration of exposure. Cadmium was heavily accumulated in the liver and transferred to the fetus only in small amounts. The zinc concentration in the maternal liver was positively correlated with the cadmium concentration. In the placenta the zinc concentration was not affected. Zinc in fetal liver was decreased from day 18 onward. Despite relatively high cadmium levels and decreased zinc levels in the fetus, we observed no adverse effects on various reproduction parameters, such as birth weights and obvious malformations.

  10. Isotopes in Condensed Matter

    CERN Document Server

    G Plekhanov, Vladimir

    2013-01-01

    This book provides a concise introduction to the newly created sub-discipline of solid state physics isotopetronics. The role of isotopes in materials and their properties are describe  in this book. The problem of the enigma of the atomic mass in microphysics is briefly discussed.  The range of the applications of isotopes is wide: from biochemical process in living organisms to modern technical applications in quantum information. Isotopetronics promises to improve nanoelectronic and optoelectronic devices. With numerous illustrations this book is useful to researchers, engineers and graduate students.

  11. An association between urinary cadmium and urinary stone disease in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    Energy Technology Data Exchange (ETDEWEB)

    Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Limpatanachote, Pisit; Krintratun, Somyot [Department of Internal Medicine, Mae Sot General Hospital, Tak 63110 (Thailand)

    2011-05-15

    Excessive urinary calcium excretion is the major risk of urinary stone formation. Very few population studies have been performed to determine the relationship between environmental cadmium exposure and urinary stone disease. This population-based study examined an association between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and prevalence of urinary stones in persons aged 15 years and older, who lived in the 12 cadmium-contaminated villages in the Mae Sot District, Tak Province, northwestern Thailand. A total of 6748 persons were interviewed and screened for urinary cadmium and urinary stone disease in 2009. To test a correlation between urinary excretion of cadmium and calcium, we measured urinary calcium content in 1492 persons, who lived in 3 villages randomly selected from the 12 contaminated villages. The rate of urinary stones significantly increased from 4.3% among persons in the lowest quartile of urinary cadmium to 11.3% in the highest quartile. An increase in stone prevalence with increasing urinary cadmium levels was similarly observed in both genders. Multiple logistic regression analysis revealed a positive association between urinary cadmium levels and stone prevalence, after adjusting for other co-variables. The urinary calcium excretion significantly increased with increasing urinary cadmium levels in both genders, after adjusting for other co-variables. Elevated calciuria induced by cadmium might increase the risk of urinary stone formation in this environmentally exposed population. - Research highlights: {yields} Excessive calciuria is the major risk of urinary stone formation. {yields} We examine cadmium-exposed persons for urinary cadmium, calcium, and stones. {yields} The rate of urinary stones increases with increasing urinary cadmium. {yields} Urinary calcium excretion increases with increasing urinary cadmium. {yields} Elevated calciuria induced by cadmium may increase the risk of urinary stones.

  12. Disposal of beryllium and cadmium from research reactors; Entsorgung von Beryllium und Cadmium aus Forschungsreaktoren

    Energy Technology Data Exchange (ETDEWEB)

    Lierse von Gostomski, C.; Remmert, A.; Stoewer, W. [Inst. fuer Radiochemie, Technische Univ. Muenchen, Garching (Germany); Bach, F.W.; Wilk, P.; Kutlu, I. [Inst. fuer Werkstoffkunde, Univ. Hannover, Hannover (Germany); Blenski, H.J.; Berthold, M. [Gesellschaft fuer Nuklear-Service mbH, Essen (Germany); Nerlich, K.D.; Plank, W. [TUeV Sueddeutschland Bau und Betrieb GmbH, Muenchen (Germany)

    2003-07-01

    Beryllium and cadmium mostly occur in metal form as radioactive special materials during the deconstruction of research reactors. Beryllium is usually used in these reactors as a neutron reflector and moderator, while cadmium is used above all as a neutron absorber. Both metals together have a high chemotoxicity as well as an inventory of radionuclides which has not been more closely characterised up to now. A high tritium content is to be expected, particularly in the case of beryllium; this tritium is due to the reaction of the metal with thermal reactor neutrons in particular. However, other nuclides which may be formed by neutron capture from impurities also contribute to the activity inventory. Up to now there is no qualified process for proper treatment, conditioning and intermediate and final repository in Germany. (orig.)

  13. Inclusion free cadmium zinc tellurium and cadmium tellurium crystals and associated growth method

    Science.gov (United States)

    Bolotnikov, Aleskey E.; James, Ralph B.

    2010-07-20

    The present disclosure provides systems and methods for crystal growth of cadmium zinc tellurium (CZT) and cadmium tellurium (CdTe) crystals with an inverted growth reactor chamber. The inverted growth reactor chamber enables growth of single, large, high purity CZT and CdTe crystals that can be used, for example, in X-ray and gamma detection, substrates for infrared detectors, or the like. The inverted growth reactor chamber enables reductions in the presence of Te inclusions, which are recognized as an important limiting factor in using CZT or CdTe as radiation detectors. The inverted growth reactor chamber can be utilized with existing crystal growth techniques such as the Bridgman crystal growth mechanism and the like. In an exemplary embodiment, the inverted growth reactor chamber is a U-shaped ampoule.

  14. Hard probes 2006 Asilomar

    CERN Multimedia

    2006-01-01

    "The second international conference on hard and electromagnetic probes of high-energy nuclear collisions was held June 9 to 16, 2006 at the Asilomar Conference grounds in Pacific Grove, California" (photo and 1/2 page)

  15. An Ultrasonographic Periodontal Probe

    Science.gov (United States)

    Bertoncini, C. A.; Hinders, M. K.

    2010-02-01

    Periodontal disease, commonly known as gum disease, affects millions of people. The current method of detecting periodontal pocket depth is painful, invasive, and inaccurate. As an alternative to manual probing, an ultrasonographic periodontal probe is being developed to use ultrasound echo waveforms to measure periodontal pocket depth, which is the main measure of periodontal disease. Wavelet transforms and pattern classification techniques are implemented in artificial intelligence routines that can automatically detect pocket depth. The main pattern classification technique used here, called a binary classification algorithm, compares test objects with only two possible pocket depth measurements at a time and relies on dimensionality reduction for the final determination. This method correctly identifies up to 90% of the ultrasonographic probe measurements within the manual probe's tolerance.

  16. Blood and urine cadmium and bioelements profile in nickel-cadmium battery workers in Serbia.

    Science.gov (United States)

    Bulat, Z Plamenac; Dukic-Cosic, D; Dokic, M; Bulat, P; Matovic, V

    2009-03-01

    Although cadmium (Cd) is extensively used for nickel-cadmium battery production, few recent reports are available on the effect of this toxic metal on the imbalance of biometals in occupational exposure. The current study was carried out to determine the Cd level and its effect on the content of bioelements: zinc, cooper, magnesium, and iron in blood and urine of workers exposed to Cd during nickel-cadmium battery production. beta(2)-microglobulins (beta(2)-MG), as indicators of kidney damage, were determined in urine.The study group comprised 32 male nickel-cadmium battery workers, and the control group had 15 male construction workers with no history of Cd exposure. Levels of Cd and bioelements were determined in blood and urine by atomic absorption spectrophotometry.Cd concentration in blood of exposed workers was around 10 microg/L and in urine ranged from 1.93 to 8.76 microg/g creatinine (cr). Urine Cd concentration was significantly higher in exposed workers than in the controls, although no statistical difference in beta(2)-MG content was observed in urine between the two groups. Blood Zn and Mg level were significantly reduced and urine Zn level was increased in Cd-exposed group when compared with controls.The mean Cd concentrations in blood and urine did not exceed the recommended reference values of 10 microg/L in blood and 10 microg/g cr in urine. Cd exposure resulted in disturbances of Zn in blood and urine and Mg in blood but had no effect on Cu and Fe content in biological fluids.

  17. Electrochemical removal of cadmium from bio-ash; Elektrokemisk fjernelse af cadmium fra bioasker

    Energy Technology Data Exchange (ETDEWEB)

    Juul Pedersen, Anne; Ottosen, Lisbeth M.; Simonsen, Peter; Christensen, Terkel C.

    2004-07-01

    The potential of using the method electrodialytic remediation for removal of cadmium from bioashes has been investigated. Five different types of fly ash from biomass combustion were included in the study: 1) A straw combustion fly ash from grate-firing at Avedoere power plant. 2) A fly ash from co-firing of wood and fuel oil at Avedoere power plant. 3) A suspended, grain size fractionated straw fly ash, obtained from PSO project FU 2201, fine and coarse size fraction. The ash was originally produced at Avedoere power plant. 4) A straw pellet fly ash from dust-firing at Amager power plant. Thr five ashes were characterised, and a series of preliminary elekctrodialytic remediation experiments were conducted on each ash. In spite a significant differences between the five ashes with respect to parameters such as pH and content of cadmium, all ashes showed promising remediation potential. For all ashes cadmium concentrations below the regulatory limits for recycling were reached in one or more of the preliminary remediation experiements. The best results were obtained with the suspended straw ash from PSO FU 2201, whereas the results with the wood chips ash, due to a high initial pH value, were less sucessful, meaning that the remediation process was progressing more slowly. (BA)

  18. Discoveries of isotopes by fission

    Indian Academy of Sciences (India)

    M Thoennessen

    2015-09-01

    Of the about 3000 isotopes presently known, about 20% have been discovered in fission. The history of fission as it relates to the discovery of isotopes as well as the various reaction mechanisms leading to isotope discoveries involving fission are presented.

  19. Soil biogeochemistry, plant physiology and phytoremediation of cadmium contaminated soils

    Science.gov (United States)

    Cadmium (Cd) loading in soil and the environment has been accelerated worldwide due to enhanced industrialization and intensified agricultural production, particularly in the developing countries. Soil Cd pollution, resulting from both anthropogenic and geogenic sources, has posed an increasing chal...

  20. Study of thermal effects on nickel-cadmium batteries

    Science.gov (United States)

    Foley, R. T.; Webster, W. H.

    1967-01-01

    Isothermal continuous flow calorimeter is designed to test a nickel-cadmium battery under numerous orbital conditions. This sensitive calorimeter collects cell data such as oxygen pressure and rate of heat generation, and calculates changes in enthalpy.

  1. EFFECTS OF CADMIUM ON THE REPRODUCTIVE AXIS OF JAPANESE MEDAKA

    Science.gov (United States)

    Cadmium (Cd) is a ubquitous element and a significant inorganic pollutant that has previously been found to bioaccumulate in reproductive organs of fish and disrupt important endocrine processes, especially those involved in synthesis, release and metabolism of hormones. Clearly,...

  2. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2013-06-01

    This National Center for Photovoltaics sheet describes the capabilities of its polycrystalline thin-film research in the area of cadmium telluride. The scope and core competencies and capabilities are discussed.

  3. Polycrystalline Thin-Film Research: Cadmium Telluride (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2011-06-01

    Capabilities fact sheet that includes scope, core competencies and capabilities, and contact/web information for Polycrystalline Thin-Film Research: Cadmium Telluride at the National Center for Photovoltaics.

  4. Electronic-structure calculations of large cadmium chalcogenide nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Frenzel, Johannes [Lehrstuhl fuer Theoretische Chemie, Ruhr-Universitaet Bochum (Germany); Joswig, Jan-Ole [Physikalische Chemie, Technische Universitaet Dresden (Germany)

    2012-02-15

    In this paper, we will review our studies of large cadmium chalcogenide nanoparticles and present some new results on cadmium telluride systems. All calculations have been performed using density-functional based methods. The studies deal with the structural properties of saturated and unsaturated nanoparticles where the surfactants generally are hydrogen atoms or thiol groups. We have focused on the investigation of the density of states, the Mulliken charges, the eigenvalue spectra, and the spatial distributions of the frontier orbitals. Optical excitation spectra of pure CdS and CdSe/CdS core-shell systems have been calculated using a linear-response formalism. The reviewed studies are compared to the state of the art of modeling large cadmium chalcogenide particles. Optical excitations in large saturated cadmium chalcogenide nanoparticles with several thousand atoms. (Copyright copyright 2012 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  5. Isotopic Implicit Surface Meshing

    NARCIS (Netherlands)

    Boissonnat, Jean-Daniel; Cohen-Steiner, David; Vegter, Gert

    2004-01-01

    This paper addresses the problem of piecewise linear approximation of implicit surfaces. We first give a criterion ensuring that the zero-set of a smooth function and the one of a piecewise linear approximation of it are isotopic. Then, we deduce from this criterion an implicit surface meshing algor

  6. Forensic Stable Isotope Biogeochemistry

    Science.gov (United States)

    Cerling, Thure E.; Barnette, Janet E.; Bowen, Gabriel J.; Chesson, Lesley A.; Ehleringer, James R.; Remien, Christopher H.; Shea, Patrick; Tipple, Brett J.; West, Jason B.

    2016-06-01

    Stable isotopes are being used for forensic science studies, with applications to both natural and manufactured products. In this review we discuss how scientific evidence can be used in the legal context and where the scientific progress of hypothesis revisions can be in tension with the legal expectations of widely used methods for measurements. Although this review is written in the context of US law, many of the considerations of scientific reproducibility and acceptance of relevant scientific data span other legal systems that might apply different legal principles and therefore reach different conclusions. Stable isotopes are used in legal situations for comparing samples for authenticity or evidentiary considerations, in understanding trade patterns of illegal materials, and in understanding the origins of unknown decedents. Isotope evidence is particularly useful when considered in the broad framework of physiochemical processes and in recognizing regional to global patterns found in many materials, including foods and food products, drugs, and humans. Stable isotopes considered in the larger spatial context add an important dimension to forensic science.

  7. Isotope hydrograph separation

    Energy Technology Data Exchange (ETDEWEB)

    Fritz, P. [UFZ-Umweltforschungszentrum, Centre of Environmental Research Leipzig-Halle, Leipzig (Germany)

    2000-07-01

    Storm-runoff thus reflects the complex hydraulic behaviour of drainage basins and water-links of such systems. Water of different origin may participate in the events and in this lecture, the application of isotope techniques to separate storm hydrographs into different components will be presented.

  8. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20072750 Huang Sijing(State Key Laboratory of Oil/Gas Reservoir Geology and Exploitation,Chengdu University of Technology,Chengdu 610059,China);Pei Changrong Age Calibration for the Boundary between Lower and Middle Triassic by Strontium Isotope Stratigraphy in Eastern Sichuan Province

  9. GEOCHRONOMETRY ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2004-01-01

    <正>20040631 Chen Jiangfeng (School of Earth and Space Sciences, University of Science and Technology of China, Hefei, Anhui) ; Xie Zhi Relationships Between Rb-Sr, Ar - Ar Geochronometers and Oxygen Isotopic Equilibrium of Intrusions from Eastern Anhui Province, China (Geological Journal of China Universities, ISSN 1006 - 7493, CN 32 -

  10. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    <正>20090432 Zhou Shuqing (School of Energy Resources, China University of Geosciences Beijing 100083, China); Huang Haiping Stable Isotopic Records vs. Important Events in Life Evolution and the Concurrent Environment (Geological Review, ISSN0371-5736, CN11-1952, 54(2), 2008, p.225-231, 3 illus., 1 table, 77 refs.)

  11. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2014-01-01

    <正>20141014Wang Hairan(State Key Laboratory of Continental Dynamics,Department of Geology,Northwest University,Xi’an710069,China);Zhao Hongge Theory and Application of Zircon U-Pb Isotope Dating Technique(Geology and Resources,ISSN1671-1947,CN21-1458/P,22(3),2013,p.229

  12. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>20070454 Bao Zengkuan (Institute of High Energy Physics, CAS, Beijing 100049, China); Yuan Wanming Apatite (U-Th)/He Dating and Its Application (Acta Petrologica et Mineralogica, ISSN1000-6524, CN11-1966/P, 24(2), 2005, p.126-132, 2 illus., 25 refs.) Key words: isotopic geochronology

  13. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Science.gov (United States)

    Rathod, K. D.; Singh, P. K.; Natarajan, Vasant

    2014-09-01

    We demonstrate generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman Slower. They are then subjected to a pair of molasses beams inclined at $45^\\circ$ with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate selective deflection of the bosonic isotope $^{174}$Yb, and the fermionic isotope $^{171}$Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  14. Cold beam of isotopically pure Yb atoms by deflection using 1D-optical molasses

    Indian Academy of Sciences (India)

    K D Rathod; P K Singh; Vasant Natarajan

    2014-09-01

    We demonstrate the generation of an isotopically pure beam of laser-cooled Yb atoms by deflection using 1D-optical molasses. Atoms in a collimated thermal beam are first slowed using a Zeeman slower. They are then subjected to a pair of molasses beams inclined at 45° with respect to the slowed atomic beam. The slowed atoms are deflected and probed at a distance of 160 mm. We demonstrate the selective deflection of the bosonic isotope 174Yb and the fermionic isotope 171Yb. Using a transient measurement after the molasses beams are turned on, we find a longitudinal temperature of 41 mK.

  15. First direct mass measurements of stored neutron-rich 129,130,131Cd isotopes with FRS-ESR

    Science.gov (United States)

    Knöbel, R.; Diwisch, M.; Bosch, F.; Boutin, D.; Chen, L.; Dimopoulou, C.; Dolinskii, A.; Franczak, B.; Franzke, B.; Geissel, H.; Hausmann, M.; Kozhuharov, C.; Kurcewicz, J.; Litvinov, S. A.; Martinez-Pinedo, G.; Matoš, M.; Mazzocco, M.; Münzenberg, G.; Nakajima, S.; Nociforo, C.; Nolden, F.; Ohtsubo, T.; Ozawa, A.; Patyk, Z.; Plaß, W. R.; Scheidenberger, C.; Stadlmann, J.; Steck, M.; Sun, B.; Suzuki, T.; Walker, P. M.; Weick, H.; Wu, M.-R.; Winkler, M.; Yamaguchi, T.

    2016-03-01

    A 410 MeV/u 238U projectile beam was used to create cadmium isotopes via abrasion-fission in a beryllium target placed at the entrance of the in-flight separator FRS at GSI. The fission fragments were separated by the FRS and injected into the isochronous storage ring ESR for mass measurements. Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without Bρ-tagging at the high-resolution central focal plane of the FRS. In the experiment with Bρ-tagging the magnetic rigidity of the injected fragments was determined with an accuracy of 2 ṡ10-4. A new method of data analysis, which uses a correlation matrix for the combined data set from both experiments, has provided experimental mass values of 25 rare isotopes for the first time. The high sensitivity and selectivity of the method have given access to nuclides detected with a rate of a few atoms per week. In this letter we present for the 129,130,131Cd isotopes mass values directly measured for the first time. The experimental mass values of cadmium as well as for tellurium and tin isotopes show a pronounced shell effect towards and at N = 82. Shell quenching cannot be deduced from a single new mass value, nor by a better agreement with a theoretical model which explicitly takes into account a quenching feature. This is in agreement with the conclusion from γ-ray spectroscopy and confirms modern shell-model calculations.

  16. LUMINESCENCE OF CADMIUM SULFIDE QUANTUM DOTS IN FLUOROPHOSPHATE GLASSES

    OpenAIRE

    Z. O. Lipatova; E. V. Kolobkova; V. A. Aseev

    2015-01-01

    Cadmium sulfide quantum dots are perspective materials in optics, medicine, biology and optoelectronics. Fluorophosphate glasses, doped with cadmium sulfide quantum dots, were examined in the paper. Heat treatment led to the formation of quantum dots with diameters equal to 2.8 nm, 3.0 nm and 3.8 nm. In view of such changes in the quantum dots size the fundamental absorption edge shift and the luminescence band are being displaced to the long wavelengths. Luminescence lifetime has been fou...

  17. Analysis Of The Underpotential Deposition Of Cadmium On Copper

    OpenAIRE

    Kowalik R.

    2015-01-01

    In this study the process of deposition of cadmium on polycrystalline copper electrode in sulfate solution was investigated. The process of underpotential and bulk deposition was analyzed by classical electrochemical method: cyclic voltammetry(CV), anodic stripping voltammetry(ASV) and electrochemical quartz crystal microbalance(EQCM). The obtained results were compared with electrochemical impedance spectroscopy(EIS) measurements. CV, EQCM and EIS results suggest that the UPD of cadmium star...

  18. Investigation of cadmium resistance in an Alcaligenes sp

    Energy Technology Data Exchange (ETDEWEB)

    McEntee, J.D.; Woodrow, J.R.; Quirk, A.V.

    1986-03-01

    The mechanisms of metal resistance of a cadmium-resistant Alcaligenes sp. were studied. Growth in a defined medium was unaffected by cadmium at concentrations up to 0.1 mM, while at concentrations up to 2.5 mM, growth occurred after an extended lag phase. The increase in length of the lag phase was abolished by repeated subculturing at these higher concentrations. However, subculture in the absence of cadmium reversed the adaptation process. Plasmid DNA was not detected in adapted cells, suggesting that adaptation is not plasmid mediated. Increased sulfide production in response to cadmium was observed, although the levels were too low to account fully for cadmium resistance. Adaptation of cells to cadmium resulted in the appearance of a major new membrane preparation. This protein was induced at cadmium concentrations of 0.1 mM and above, but below this level the protein was absent. The onset of growth at concentrations above 0.1 mM was coincident with the appearance of this protein, which was also induced by zinc (0.4 mM) but not by manganese or nickel. The protein was only solubilized by a sodium dodecyl sulfate-2-mercaptoethanol mixture. Similar solubility properties were shown by a second major membrane protein (molecular weight, 33,000). These two proteins proved to be similar by peptide-mapping experiments and amino acid analysis. The appearance of the 34,500-molecular-weight protein and its possible role in cadmium resistance are discussed.

  19. Study on Systemic Separation of Palladium, Silver, Cadmium and Tin

    Institute of Scientific and Technical Information of China (English)

    YU; Zhen-hua; HUANG; Kun

    2013-01-01

    To accurately measure the yields of palladium,silver,cadmium and tin that generated from the fission of plutonium,radiochemical method is needed because there is much interference in using directγ-spectroscopy measurements.Usually,we want to get as much as possible the experiment data from one target,so it is required systemic separation of palladium,silver,cadmium and tin.Considering the

  20. Harmful effects of cadmium on olfactory system in mice.

    Science.gov (United States)

    Bondier, Jean-Robert; Michel, Germaine; Propper, Alain; Badot, Pierre-Marie

    2008-10-01

    The inhalation of certain metals can result in olfactory epithelial injury, an altered sense of smell, and direct delivery of the metal from the olfactory epithelium to the olfactory bulbs and other parts of the central nervous system. The purpose of this study was to examine whether mice given an intranasal instillation of cadmium would develop altered olfactory function and to assess whether cadmium may be transported directly from the olfactory epithelium to the central nervous system. To evaluate cadmium's ability to induce anosmia and on the basis of olfactory epithelium sensitivity to metals, the aim of this study was first to study cadmium effects on the olfactory function and secondly to check whether cadmium may be transported from the nasal area to the central nervous system. After an intranasal instillation of a solution containing CdCl2 at 136 mM, we observed in treated mice: (1) a partial destruction of the olfactory epithelium, which is reduced to three or four basal cell layers followed by a progressive regeneration; (2) a loss of odor discrimination with a subsequent recovery; and (3) a cadmium uptake by olfactory bulbs demonstrated using atomic absorption spectrophotometry, but not by other parts of the central nervous system. Cadmium was delivered to the olfactory bulbs, most likely along the olfactory nerve, thereby bypassing the intact blood-brain barrier. We consider that cadmium can penetrate olfactory epithelium and hence be transported to olfactory bulbs. The olfactory route could therefore be a likely way to reach the brain and should be taken into account for occupational risk assessments for this metal.

  1. Update on Alternatives for Cadmium Coatings on Military Electrical Connectors

    Science.gov (United States)

    2010-03-01

    deposi- tion (PVD) process in which a part is placed in a vacuum chamber and glow discharge cleaned. Pure alu- minum is then melted in heated ceramic...alloys, beryllium , magne- sium, and aluminum alloys are gen- erally the most active metals in cor- rosive environments and, therefore, are the only...materials that can pro- vide sacrificial corrosion protection similar to cadmium in this applica- tion. However, beryllium is more hazardous than cadmium

  2. Synthesis and Electroluminescence Characterization of Cadmium Complex

    Directory of Open Access Journals (Sweden)

    Rahulkumar

    2011-01-01

    Full Text Available We have synthesized and characterized a new electroluminescence material,Cadmium [(2-(2-hydroxyphenylbenzoxazole(8-hydoxyquinoline] Cd(HPBq. The absorption spectra of this material show maxima at 378 nm. It may be attributed due to π° – π* transition. The photoluminescence showed peak at 520 nm. TGA data of the material shows stability up to 370 °C .Organic light emitting diode have been fabricated with this material and the fundamental structures of the device is ITO/α-NPD/ Cd(HPBq/BCP/Alq3/LiF/Al exhibited a luminescence peak at 550 nm. The maximum luminescence of the device was 295 cd/m2 with current density of 6687 A/m2 at 20 V. The maximum current efficiency of OLED was 1.01 cd/A at 17 V and power efficiency was 1.01 lm/w at 17 V.

  3. Soil Cadmium Regulates Antioxidases in Sorghum

    Institute of Scientific and Technical Information of China (English)

    LIU Da-lin; ZHANG Shu-pan; CHEN Zheng; QIU Wei-wei

    2010-01-01

    The regulatory mechanism of soil cadmium(Cd)on antioxidases in sorghum was studied using 3 sorghum species viz.,sweet sorghum[Sorghum bicolor(L.)]Moench.cv.Hunnigreen,sorghum hybrid sudangrass(Sorghum bicolor × S.sudanense,cv.Everlush)and sudangrass[Sorghum sudanense(Piper)Stapf cv.Xinjiang].The results showed that low concentrations of Cd2+(≤10 mg kg-1)induced the activities of 4 antioxidases in leaves of the 3 species of sorghum,but high Cd2+concentrations(≥50 mg kg-1)significantly reduced the activities of all the four antioxidases.The glutathione(GSH)contents in leaves of the 3 species of sorghum correlated positively with the Cd2+concentrations.The maximum antioxidase activities were observed at the elongation stage of sorghum during the whole growth period.

  4. Cadmium substituted high permeability lithium ferrite

    Indian Academy of Sciences (India)

    S S Bellad; S C Watawe; A M Shaikh; B K Chougule

    2000-04-01

    Polycrystalline Li0.5–/2 Cd Fe2.5–/2O4 ferrites where = 0, 0.1, 0.2, 0.3, 0.4, 0.5 and 0.6 were prepared by a double sintering ceramic technique and characterized by X-ray diffraction and scanning electron microscopy (SEM). The lattice parameter is found to increase monotonically with the cadmium content. It is explained in terms of the sizes of component ions. The grain size of the samples increases up to = 0.3 and then it decreases for higher values of . A similar trend is observed in the variation of Ms with Cd2+ content. The initial permeability () is however found to increase continuously with . The increase in is attributed to decrease of anisotropy constant K1 and higher grain size of the samples.

  5. Nickel-cadmium cell residual charge analyser

    Energy Technology Data Exchange (ETDEWEB)

    Marshall, W.G.; Leek, R.; Hampson, N.A.; Lovelock, G.R.

    1984-09-01

    This paper describes a portable unit for measuring the charge remaining in nickel-cadmium secondary cells. Exhaustive frequency response tests have confirmed that cell impedance varies very little with charge state, with the possible exception of that at very low frequencies (< 50 mHz). In the interim before further work in this area is carried out, a microprocessor-based test unit has been built which uses a current pulse discharge method to arrive at a residual charge reading. When the cell is discharged according to a particular regime, the unit produces results accurate to within 10-15% over the entire range of charge. Further development involving the inclusion of cell history parameters promises to make the unit useful for military and other applications.

  6. Modelling and interpreting the isotopic composition of water vapour in convective updrafts

    Directory of Open Access Journals (Sweden)

    M. Bolot

    2013-08-01

    Full Text Available The isotopic compositions of water vapour and its condensates have long been used as tracers of the global hydrological cycle, but may also be useful for understanding processes within individual convective clouds. We review here the representation of processes that alter water isotopic compositions during processing of air in convective updrafts and present a unified model for water vapour isotopic evolution within undiluted deep convective cores, with a special focus on the out-of-equilibrium conditions of mixed-phase zones where metastable liquid water and ice coexist. We use our model to show that a combination of water isotopologue measurements can constrain critical convective parameters, including degree of supersaturation, supercooled water content and glaciation temperature. Important isotopic processes in updrafts include kinetic effects that are a consequence of diffusive growth or decay of cloud particles within a supersaturated or subsaturated environment; isotopic re-equilibration between vapour and supercooled droplets, which buffers isotopic distillation; and differing mechanisms of glaciation (droplet freezing vs. the Wegener–Bergeron–Findeisen process. As all of these processes are related to updraft strength, particle size distribution and the retention of supercooled water, isotopic measurements can serve as a probe of in-cloud conditions of importance to convective processes. We study the sensitivity of the profile of water vapour isotopic composition to differing model assumptions and show how measurements of isotopic composition at cloud base and cloud top alone may be sufficient to retrieve key cloud parameters.

  7. Systematic study of proton capture rates for Mo and Cd isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Bajpeyi, Awanish; Shukla, A. [Rajiv Gandhi Institute of Petroleum Technology, Department of Physics, Raebareli (India); Koning, A.J. [Nuclear Research and Consultancy Group NRG, Petten (Netherlands); Aaberg, Sven [Lund University, Mathematical Physics, P.O. Box 118, Lund (Sweden)

    2015-12-15

    Proton capture reactions play a very important role in the understanding of nucleosynthesis. In the present work, p-capture reactions have been studied coherently with nuclear structure for the nuclei under consideration. We have calculated proton capture cross sections and S-factor for relevant isotopes of molybdenum and cadmium in the energy range 2.0 to 4.5 Mev. Calculated results for nuclear structure as well reaction rates are compared with the available experimental and theoretical results and are found to be in good agreement. (orig.)

  8. Aspects of the biochemical toxicology of cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Singhal, R.L.; Merali, Z.; Hrdina, P.D.

    1976-01-01

    Cadmium, in addition to producing a variety of toxic manifestations, is known to accumulate in certain ''target'' organs which include liver and kidney where histological and functional damage becomes apparent. The daily intraperitoneal injection of cadmium chloride for 21 or 45 days stimulated the activities of hepatic pyruvate carboxylase, phosphoenolpyruvate carboxykinase, fructose-1,6-diphosphatase and glucose-6-phosphatase, elevated blood glucose and urea, and lowered hepatic glycogen in rats. Whereas chronic Cd treatment failed to alter adenosine-3',5'-monophosphate phosphodiesterase (PDE) activity, cyclic AMP (cAMP) and the activity of basal and fluoride-stimulated forms of hepatic adenylate cyclase (AC) were markedly increased. However, the cAMP binding to hepatic protein kinase was decreased as was the kinase activity ratio. An acute dose of Cd decreased hepatic glycogen content and increased blood glucose, serum urea, and hepatic cAMP. Chronic exposure to Cd induced adrenal hypertrophy and augmented adrenal norepinephrine and epinephrine as well as the activity of adrenal tyrosine hydroxylase. In most cases, the observed metabolic alterations persisted up to 28 days on cessation of Cd administration. Subacute Cd treatment suppressed pancreatic function as evidenced by lowered serum immunoreactive insulin in presence of hyperglycemia, as well as by partial inhibition of phentolamine-stimulated increases in serum IRI. Although chronic Cd treatment failed to alter the concentration of brain stem norepinephrine and cerebrocortical acetylcholine esterase activity, serotonin levels of brain stem were depressed and the concentration of striatal dopamine and cerebrocortical acetylcholine were significantly elevated when compared with the values seen in control nonexposed animals.

  9. Cadmium in goods - contribution to environmental exposure

    Energy Technology Data Exchange (ETDEWEB)

    Bergbaeck, B.; Jonsson, Arne [Kalmar Univ. (Sweden). Dept. of Natural Science

    1998-03-01

    The total amount of Cd used in Sweden since 1940 is approximately 5000 tonnes, including alloys, fertilizers and impurities in zinc. The stock of Cd in goods in the Swedish anthroposphere is dominated by NiCd-batteries. However, when one considers the degree of exposure to corrosion, Cd stabilizers are dominant. Emissions of Cd from industrial plants and other point sources have been historically important. However, these point source emissions must be seen in relation to the increasingly significant fugitive `consumption emissions`, from the use and/or end-use of various goods. In this study, methods of reconstructing the flows of cadmium (Cd) and estimating the emissions over time are discussed. This is done through studies of the development of production, technology, trade and the longevity of metals in Swedish society. This last part in the chain will form the `consumption emissions` calculated from emission factors giving the proportion of the cadmium content in goods that eventually will reach the environment. The main accumulation of metals in the anthroposphere occurs in urban areas where the influx of metals is greatest. Urban areas probably represent `hot spots` as far as this type of environmental impact is concerned. Extreme Cd concentrations in surface sediments in central Stockholm indicate an ongoing release of Cd from the anthroposphere. The sources are so far unknown, i.e. this Cd flow to the biosphere cannot be explained in terms of deposition or emissions from point sources. Approximately 40 tonnes of Cd in goods are exposed to corrosion in varying degrees. This stock is dominated by Cd in stabilizers and pigments, and as impurities in Zn 15 refs, 2 figs, 8 tabs

  10. Lead isotopes and trace metals in dust at Yucca Mountain

    Science.gov (United States)

    Kwak, Loretta; Neymark, Leonid A.; Peterman, Zell E.

    2008-01-01

    Lead (Pb)-isotope compositions and trace-metal concentrations were determined for samples of dust collected from underground and surface locations at and near the proposed radioactive waste repository at Yucca Mountain, Nevada. Rare earth element concentrations in the dust samples from the underground tunnels are similar to those in wholerock samples of the repository host rocks (Miocene Tiva Canyon Tuff and Topopah Spring Tuff), supporting interpretation that the subsurface dust is mainly composed of rock comminuted during tunnel construction. Other trace metals (arsenic, cadmium, cobalt, chromium, copper, manganese, nickel, lead, antimony, thallium, and zinc) are variably enriched in the subsurface dust samples relative to the average concentrations in the host rocks. Average concentrations of arsenic and lead in dust samples, high concentrations of which can cause corrosion of waste canisters, have enrichment factors from 1.2 to 1.6 and are insignificant relative to the range of concentrations for these metals observed in the host rock samples. Most dust samples from surface sites also are enriched in many of these trace metals relative to average repository host rocks. At least some of these enrichments may be artifacts of sampling. Plotted on a 208Pb/206Pb-207Pb/206Pb graph, Pb-isotope compositions of dust samples from underground sites form a mixing line extending from host-rock Pb-isotope compositions towards compositions of many of the dust samples from surface sites; however, combined Pb concentration and isotope data indicate the presence of a Pbenriched component in the subsurface dust that is not derived from host rock or surface dust and may derive from anthropogenic materials introduced into the underground environment.

  11. Thick Target Yield Measurement for PAC Probe Producing Reaction Mo (19F, xn)111In

    Institute of Scientific and Technical Information of China (English)

    ZHENGYong-nan; ZHOUDong-mei; DUEn-peng; YUANDa-qing; ZUOYi; CHENXiong-jun; WUXiao-guang; CUIBao-qun; ZHUSheng-yun

    2003-01-01

    Perturbed angular correlation (PAC) directly determines the hyperfine interaction acting on the PAC probe nuclei, which is a sensitive and precise method for microscopic analysis on an atomic scale, 111Cd is the most frequently used PAC probe nuclei, the mother nuclei of which is 111In. The on-line isotope separator (ISOL) based on the HI-13 tandem accelerator is being developed at China Institute of Atomic Energy, which produces the radioactive nuclear beams for the on-line PAC measurements.

  12. Statolith formation in Cnidaria: effects of cadmium on Aurelia statoliths

    Science.gov (United States)

    Spangenberg, D. B.

    1986-01-01

    Statolith formation in Cnidaria was reviewed with an emphasis on Aurelia statoliths. The review provides information on the chemical composition, mechanisms of initiation of mineralization, and effects of environmental factors on Cnidarian statolith formation. Environmental factors discussed included modified sea water ingredients, X-irradiation, clinostat rotation, and petroleum oil ingredients. A detailed account of the effects of cadmium on mineralization and demineralization of Aurelia statoliths is given. Cadmium at dosages of 2 to 4 micromoles significantly reduces statolith numbers in developing ephyrae. At a dosage of 3 micromoles, cadmium accelerates statolith loss in unfed ephyrae studied at 4 and 8 days following ephyrae release from strobilae. Cadmium, therefore, is shown to reduce statolith numbers in developing ephyrae and to cause greater reduction of statolith numbers in unfed ephyrae after 4 and 8 days than occurred in controls. Supplementation of Cd(2+)-containing artificial sea water (ASW) with calcium (3X and 5X ASW calcium content) results in higher numbers of statoliths at day 4 as compared with cadmium-treated ephyrae. At 8 days only the 5X calcium supplemented ASW is effective in enhancing statolith numbers in Cd(2+)-treated ephyrae. These results suggest that cadmium competes in some manner with calcium at the mineralizing sites of Aurelia.

  13. Gastrointestinal absorption of cadmium in mice during gestation and lactation

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, M.H. (Argonne National Lab., IL); Whelton, B.D.; Peterson, D.P.

    1982-01-01

    The effect on cadmium retention of continuous exposure to drinking water containing low levels of cadmium during pregnancy and lactation was studied in mice. Female mice were provided drinking water ad libitum containing /sup 109/CdCl/sub 2/ (0.03 ..mu..Ci /sup 109/Cd/ml, 0.11 ppb total cadmium) throughout either gestation, lactation, or a combined period of pregnancy and lactation. Nonpregnant control mice were exposed to the same cadmium solution for similar time periods. Dams in all three experimental groups retained two to three times cadmium (expressed as percentage of ingested dose) than did nonpregnant controls. The /sup 109/Cd contents of liver, kidney, mammary tissue, and duodenum increased strikingly in all three groups. Increases in kidney and mammary tissue were particularly apparent during lactation, with increases of fivefold for kidney and at least ninefold for mammary tissue, compared to levels in nonpregnant controls. Increases in /sup 109/Cd retention by the duodenum were fivefold during gestation and three- to fourfold during lactation. The kidneys of dams exposed during lactation retained 53% of the whole body /sup 109/Cd, while kidneys of nonpregnant controls retained only 27%. Results indicate that pregnant and lactating mice absorb and subsequently retain substantially more cadmium from their diets than do nonpregnant mice.

  14. 113Cd solid-state NMR for probing the coordination sphere in metal-organic frameworks.

    Science.gov (United States)

    Kuttatheyil, Anusree Viswanath; Handke, Marcel; Bergmann, Jens; Lässig, Daniel; Lincke, Jörg; Haase, Jürgen; Bertmer, Marko; Krautscheid, Harald

    2015-01-12

    Spectroscopic techniques are a powerful tool for structure determination, especially if single-crystal material is unavailable. (113)Cd solid-state NMR is easy to measure and is a highly sensitive probe because the coordination number, the nature of coordinating groups, and the geometry around the metal ion is reflected by the isotropic chemical shift and the chemical-shift anisotropy. Here, a detailed investigation of a series of 27 cadmium coordination polymers by (113)Cd solid-state NMR is reported. The results obtained demonstrate that (113)Cd NMR is a very sensitive tool to characterize the cadmium environment, also in non-single-crystal materials. Furthermore, this method allows the observation of guest-induced phase transitions supporting understanding of the structural flexibility of coordination frameworks.

  15. Formation and Characterization of Mixed Crystals Based on Bis (Thiourea)Cadmium Chloride and Bis (Thiourea)Cadmium Iodide

    OpenAIRE

    2014-01-01

    Bis(thiourea)cadmium chloride(BTCC) and bis(thiourea)cadmium iodide (BTCI) are metal complexes of thiourea having better nonlinear optical properties than KH2PO4. An attempt has been made in the present study to form mixed crystals based on BTCC and BTCI (even though their crystal lattices mismatch) from aqueous solutions, the precursors mixed in proper proportions. A total of seven (including the end members) crystals were formed by the free evaporation method and characteriz...

  16. Oxygen isotopic ratios in intermediate-mass red giants

    CERN Document Server

    Lebzelter, Thomas; Hinkle, Kenneth; Nowotny, Walter; Aringer, Bernhard

    2015-01-01

    Context. The abundances of the three main isotopes of oxygen are altered in the course of the CNO-cycle. When the first dredge-up mixes the burning products to the surface, the nucleosynthesis processes can be probed by measuring oxygen isotopic ratios. Aims. By measuring 16O/17O and 16O/18O in red giants of known mass we compare the isotope ratios with predictions from stellar and galactic evolution modelling. Methods. Oxygen isotopic ratios were derived from the K-band spectra of six red giants. The sample red giants are open cluster members with known masses of between 1.8 and 4.5 Msun . The abundance determination employs synthetic spectra calculated with the COMARCS code. The effect of uncertainties in the nuclear reaction rates, the mixing length, and of a change in the initial abundance of the oxygen isotopes was determined by a set of nucleosynthesis and mixing models using the FUNS code. Results. The observed 16O/17O ratios are in good agreement with the model results, even if the measured values do ...

  17. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Energy Technology Data Exchange (ETDEWEB)

    Li Shengqing [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Supervision, Inspection and Testing Center of Microbial Products Quality (Wuhan), Ministry of Agriculture (China)], E-mail: sqingli@mail.hzau.edu.cn; Cai Shun; Hu Wei [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Chen Hao [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)], E-mail: hchenhao@mail.hzau.edu.cn; Liu Hanlan [Department of Chemistry, College of Science, Huazhong Agricultural University, Wuhan 430070 (China)

    2009-07-15

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF{sub 6}), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF{sub 6}. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 {mu}L of HMIMPF{sub 6} as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L{sup - 1}, and the characteristic mass (m{sub 0}, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L{sup - 1} Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  18. Ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction combined with electrothermal atomic absorption spectrometry for a sensitive determination of cadmium in water samples

    Science.gov (United States)

    Li, Shengqing; Cai, Shun; Hu, Wei; Chen, Hao; Liu, Hanlan

    2009-07-01

    A new method was developed for the determination of cadmium in water samples using ionic liquid-based ultrasound-assisted dispersive liquid-liquid microextraction (IL-based USA-DLLME) followed by electrothermal atomic absorption spectrometry (ETAAS). The IL-based USA-DLLME procedure is free of volatile organic solvents, and there is no need for a dispersive solvent, in contrast to conventional DLLME. The ionic liquid, 1-hexyl-3-methylimidazolium hexafluorophosphate (HMIMPF 6), was quickly disrupted by an ultrasonic probe for 1 min and dispersed in water samples like a cloud. At this stage, a hydrophobic cadmium-DDTC complex was formed and extracted into the fine droplets of HMIMPF 6. After centrifugation, the concentration of the enriched cadmium in the sedimented phase was determined by ETAAS. Some effective parameters of the complex formation and microextraction, such as the concentration of the chelating agent, the pH, the volume of the extraction solvent, the extraction time, and the salt effect, have been optimized. Under optimal conditions, a high extraction efficiency and selectivity were reached for the extraction of 1.0 ng of cadmium in 10.0 mL of water solution employing 73 µL of HMIMPF 6 as the extraction solvent. The enrichment factor of the method is 67. The detection limit was 7.4 ng L - 1 , and the characteristic mass ( m0, 0.0044 absorbance) of the proposed method was 0.02 pg for cadmium (Cd). The relative standard deviation (RSD) for 11 replicates of 50 ng L - 1 Cd was 3.3%. The method was applied to the analysis of tap, well, river, and lake water samples and the Environmental Water Reference Material GSBZ 50009-88 (200921). The recoveries of spiked samples were in the range of 87.2-106%.

  19. Correlations of urinary cadmium with hypertension and diabetes in persons living in cadmium-contaminated villages in northwestern Thailand: A population study

    Energy Technology Data Exchange (ETDEWEB)

    Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Limpatanachote, Pisit; Krintratun, Somyot [Department of Internal Medicine, Mae Sot General Hospital, Tak (Thailand)

    2010-08-15

    Risk for hypertension and diabetes has not been conclusively found to be a result of cadmium exposure. A population-based study was conducted in 2009 to examine the correlations of urinary cadmium, a good biomarker of long-term cadmium exposure, with hypertension and diabetes in persons aged 35 years and older who lived in the 12 cadmium-contaminated rural villages in northwestern Thailand. A total of 5273 persons were interviewed and screened for urinary cadmium, hypertension, and diabetes. The geometric mean level of urinary cadmium for women (2.4{+-}2.3 {mu}g/g creatinine) was significantly greater than that for men (2.0{+-}2.2 {mu}g/g creatinine). Hypertension was presented in 29.8% of the study population and diabetes was detected in 6.6%. The prevalence of hypertension significantly increased from 25.0% among persons in the lowest tertile of urinary cadmium to 35.0% in the highest tertile. In women, the rate of hypertension significantly increased with increasing urinary cadmium levels in both ever and never smokers, after adjusting for age, alcohol consumption, body mass index, and diabetes. In men, such association was less significantly found in never smokers. The study revealed no significant association between urinary cadmium and diabetes in either gender. Our study supports the hypothesis that environmental exposure to cadmium may increase the risk of hypertension. Risk for diabetes in relation to cadmium exposure remains uncertain in this exposed population.

  20. Effects of cadmium accumulation from suspended sediments and phytoplankton on the Oyster Saccostrea glomerata

    Energy Technology Data Exchange (ETDEWEB)

    Schmitz, Helena A.; Maher, William A., E-mail: bill.maher@canberra.edu.au; Taylor, Anne M.; Krikowa, Frank

    2015-03-15

    Highlights: • Saccostrea glomerata accumulated cadmium from sediments and phytoplankton. • Effects were similar for both pathways. • Antioxidant capacity, lipid peroxidation and lysosomal destabilisation were affected. • Clear exposure–dose–response relationships were demonstrated. - Abstract: Metals are accumulated by filter feeding organisms via water, ingestion of suspended sediments or food. The uptake pathway can affect metal toxicity. Saccostrea glomerata were exposed to cadmium through cadmium-spiked suspended sediments (19 and 93 μg/g dry mass) and cadmium-enriched phytoplankton (1.6–3 μg/g dry mass) and cadmium uptake and effects measured. Oysters accumulated appreciable amounts of cadmium from both low and high cadmium spiked suspended sediment treatments (5.9 ± 0.4 μg/g and 23 ± 2 μg/g respectively compared to controls 0.97 ± 0.05 μg/g dry mass). Only a small amount of cadmium was accumulated by ingestion of cadmium-enriched phytoplankton (1.9 ± 0.1 μg/g compared to controls 1.2 ± 0.1 μg/g). In the cadmium spiked suspended sediment experiments, most cadmium was desorbed from sediments and cadmium concentrations in S. glomerata were significantly related to dissolved cadmium concentrations (4–21 μg/L) in the overlying water. In the phytoplankton feeding experiment cadmium concentrations in overlying water were <0.01 μg/L. In both exposure experiments, cadmium-exposed oysters showed a significant reduction in total antioxidant capacity and significantly increased lipid peroxidation and percentage of destabilised lysosomes. Destabilised lysosomes in the suspended sediments experiments also resulted from stress of exposure to the suspended sediments. The study demonstrated that exposure to cadmium via suspended sediments and to low concentrations of cadmium through the ingestion of phytoplankton, can cause sublethal stress to S. glomerata.

  1. 128CADMIUM:. Ugly Duckling or Young Swan

    Science.gov (United States)

    Walters, W. B.; Hoteling, N.; Hecht, A. A.; Tomlin, B. E.; Mantica, P. F.; Pereira, J.; Becerril, A.; Fleckstein, T.; Lorusso, G.; Pinter, J. S.; Stoker, J. B.

    2008-08-01

    The presence of isomeric levels with half lives in the microsecond range has been identified in 125,126,127,128Cd These Cd isotopes were produced from the fragmentation of a 120-MeV/nucleon 136Xe beam and uniquely identified through their time-of-fight, energy loss, and total kinetic energy. Gamma rays from these isomeric levels were measured with an array of Ge detectors that were gated for a period of 15 μs y a particle implantation trigger. The gamma rays found for the 125,127Cd isomers appear to be consistent with expected yrast structures observed in lighter, odd-mass Ce isotopes. The appearance of isomers at the point where N/Z exceeds 1.6 is interpreted as an indication of the onset of a weakened neutron-neutron and proton-neutron interaction.

  2. Probing neutrinoless double beta decay with SNO+

    CERN Document Server

    Arushanova, Evelina

    2015-01-01

    Probing neutrinoless double beta decay is one of the primary goals for SNO+, SNOLAB's multi-purpose neutrino detector. In order to achieve this goal the SNO detector has been adapted so that it can be filled with Te-loaded liquid scintillator. During the initial double beta phase the target loading is 0.3% natural Te, which equates to $\\sim790$ kg of double beta isotope. Estimating the sensitivity to neutrinoless double beta decay requires a well understood background model. For SNO+ this is provided by a comprehensive study considering all possible background contributions, whether they originate from within the liquid scintillator cocktail, the surrounding parts of the detector or other irreducible backgrounds. Given these considerations, for five years running in the initial phase, the expected sensitivity is $T_{1/2}^{0\

  3. HERA: an atmospheric probe to unveil the depths of Saturn

    Science.gov (United States)

    Mousis, Olivier; Atkinson, David H.; Amato, Michael; Aslam, Shahid; Atreya, Sushil K.; Blanc, Michel; Bolton, Scott J.; Brugger, Bastien; Calcutt, Simon; Cavalié, Thibault; Charnoz, Sébastien; Coustenis, Athena; DELEUIL, Magali; Ferri, Francesca; Fletcher, Leigh N.; Guillot, Tristan; Hartogh, Paul; Holland, Andrew; Hueso, Ricardo; Keller, Christoph; Kessler, Ernst; Lebreton, Jean-Pierre; leese, Mark; Lellouch, Emmanuel; Levacher, Patrick; Marty, Bernard; Morse, Andrew; Nixon, Conor; Reh, Kim R.; Renard, Jean-Baptiste; Sanchez-Lavega, Agustin; Schmider, François-Xavier; Sheridan, Simon; Simon, Amy A.; Snik, Frans; Spilker, Thomas R.; Stam, Daphne M.; Venkatapathy, Ethiraj; Vernazza, Pierre; Waite, J. Hunter; Wurz, Peter

    2016-10-01

    The Hera Saturn entry probe mission is proposed as an M-class mission led by ESA with a significant collaboration with NASA. It consists of a Saturn atmospheric probe and a Carrier-Relay spacecraft. Hera will perform in situ measurements of the chemical and isotopic compositions as well as the dynamics of Saturn's atmosphere, with the goal of improving our understanding of the origin, formation, and evolution of Saturn, the giant planets and their satellite systems, with extrapolation to extrasolar planets.The primary science objectives will be addressed by an atmospheric entry probe that would descend under parachute and carry out in situ measurements beginning in the stratosphere to help characterize the location and properties of the tropopause, and continue into the troposphere to pressures of at least 10 bars. All of the science objectives, except for the abundance of oxygen, which may be only addressed indirectly via observations of species whose abundances are tied to the abundance of water, can be achieved by reaching 10 bars. As in previous highly successful collaborative efforts between ESA and NASA, the proposed mission has a baseline concept based on a NASA-provided carrier/data relay spacecraft that would deliver the ESA-provided atmospheric probe to the desired atmospheric entry point at Saturn. ESA's proposed contribution should fit well into the M5 Cosmic Vision ESA call cost envelope.A nominal mission configuration would consist of a probe that detaches from the carrier one to several months prior to probe entry. Subsequent to probe release, the carrier trajectory would be deflected to optimize the over-flight phasing of the probe descent location for both probe data relay as well as performing carrier approach and flyby science, and would allow multiple retransmissions of the probe data for redundancy. The Saturn atmospheric entry probe would in many respects resemble the Jupiter Galileo probe. It is anticipated that the probe architecture for

  4. GEOCHRONOMETRY &ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20131727 Huang Xiaowen(State Key Laboratory of Ore Deposit Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550002,China);Qi Liang Preliminary Study on Sample-Preparation for Re-Os Isotopic Dating of Pyrite(Geochimica,ISSN0379-1726,CN44-1398/P,41(4),2012,p.380-386,3illus.,2tables,25refs)Key words:pyrite,Re-Os dating

  5. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    <正>20050934 Chen Zhihong (Chinese Academy of Geological Sciences, Beijing 100037, China); Lu Songnian Age of the Fushui Intermediate-Mafic Intrusive Complex in the Qinling Orogen, New Zircon U - Pb and Whole -Rock Sm and Nd Isotope Chronological Evidence (Geological Bulletin of China, ISSN 1671-2552, CN11-4648/P, 23(4), 2004, p. 322-328, 3 illus. , 3 tables, 10 refs. )

  6. GEOCHRONOMETRY & ISOTOPE GEOLOGY

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    <正>20132601 Cui Yurong(Tianjin Institute of Geology and Mineral Resources,China Geological Survey,Tianjin 300170,China);Zhou Hongying In Situ LA-MC-ICP-MS U-Pb Isotopic Dating of Monazite(Acta Geoscientica Sinica,ISSN0375-5444,CN11-1856/P,33(6),2012,p.865-876,6illus.,4tables,41refs.)Key words:monazite,U-Pb dating

  7. ISOTOPE METHODS IN HOMOGENEOUS CATALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    BULLOCK,R.M.; BENDER,B.R.

    2000-12-01

    The use of isotope labels has had a fundamentally important role in the determination of mechanisms of homogeneously catalyzed reactions. Mechanistic data is valuable since it can assist in the design and rational improvement of homogeneous catalysts. There are several ways to use isotopes in mechanistic chemistry. Isotopes can be introduced into controlled experiments and followed where they go or don't go; in this way, Libby, Calvin, Taube and others used isotopes to elucidate mechanistic pathways for very different, yet important chemistries. Another important isotope method is the study of kinetic isotope effects (KIEs) and equilibrium isotope effect (EIEs). Here the mere observation of where a label winds up is no longer enough - what matters is how much slower (or faster) a labeled molecule reacts than the unlabeled material. The most careti studies essentially involve the measurement of isotope fractionation between a reference ground state and the transition state. Thus kinetic isotope effects provide unique data unavailable from other methods, since information about the transition state of a reaction is obtained. Because getting an experimental glimpse of transition states is really tantamount to understanding catalysis, kinetic isotope effects are very powerful.

  8. Carbon isotope fractionation in protoplanetary disks

    CERN Document Server

    Woods, Paul M

    2008-01-01

    We investigate the gas-phase and grain-surface chemistry in the inner 30 AU of a typical protoplanetary disk using a new model which calculates the gas temperature by solving the gas heating and cooling balance and which has an improved treatment of the UV radiation field. We discuss inner-disk chemistry in general, obtaining excellent agreement with recent observations which have probed the material in the inner regions of protoplanetary disks. We also apply our model to study the isotopic fractionation of carbon. Results show that the fractionation ratio, 12C/13C, of the system varies with radius and height in the disk. Different behaviour is seen in the fractionation of different species. We compare our results with 12C/13C ratios in the Solar System comets, and find a stark contrast, indicative of reprocessing.

  9. Absolute photoneutron cross sections of Sm isotopes

    Energy Technology Data Exchange (ETDEWEB)

    Gheorghe, I.; Glodariu, T. [National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Utsunomiya, H. [Department of Physics, Konan University, Okamoto 8-9-1, Higashinada, Kobe 658-8501 (Japan); Filipescu, D. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6 and National Institute for Physics and Nuclear Engineering Horia Hulubei, str. Atomistilor nr. 407 (Romania); Nyhus, H.-T.; Renstrom, T. [Department of Physics, University of Oslo, N-0316 Oslo (Norway); Tesileanu, O. [Extreme Light Infrastructure - Nuclear Physics, str. Atomistilor nr. 407, Bucharest-Magurele, P.O.BOX MG6 (Romania); Shima, T.; Takahisa, K. [Research Center for Nuclear Physics, Osaka University, Suita, Osaka 567-0047 (Japan); Miyamoto, S. [Laboratory of Advanced Science and Technology for Industry, University of Hyogo, 3-1-2 Kouto, Kamigori, Hyogo 678-1205 (Japan)

    2015-02-24

    Photoneutron cross sections for seven samarium isotopes, {sup 144}Sm, {sup 147}Sm, {sup 148}Sm, {sup 149}Sm, {sup 150}Sm, {sup 152}Sm and {sup 154}Sm, have been investigated near neutron emission threshold using quasimonochromatic laser-Compton scattering γ-rays produced at the synchrotron radiation facility NewSUBARU. The results are important for nuclear astrophysics calculations and also for probing γ-ray strength functions in the vicinity of neutron threshold. Here we describe the neutron detection system and we discuss the related data analysis and the necessary method improvements for adapting the current experimental method to the working parameters of the future Gamma Beam System of Extreme Light Infrastructure - Nuclear Physics facility.

  10. Effect of Chlorella vulgaris intake on cadmium detoxification in rats fed cadmium.

    Science.gov (United States)

    Kim, You Jin; Kwon, Sanghee; Kim, Mi Kyung

    2009-01-01

    The aim of this study was to investigate if dietary Chlorella vulgaris (chlorella) intake would be effective on cadmium (Cd) detoxification in rats fed dietary Cd. Fourteen-week old male Sprague-Dawley (SD) rats weighing 415.0 +/- 1.6 g were randomly divided into two groups and fed slightly modified American Institute of Nutrition-93 Growing (AIN-93G) diet without (n=10) or with (n=40) dietary Cd (200 ppm) for 8 weeks. To confirm alteration by dietary Cd intake, twenty rats fed AIN-93G diet without (n=10) and with (n=10) dietary Cd were sacrificed and compared. Other thirty rats were randomly blocked into three groups and fed slightly modified AIN-93G diets replacing 0 (n=10), 5 (n=10) or 10% (n=10) chlorella of total kg diet for 4 weeks. Daily food intake, body weight change, body weight gain/calorie intake, organ weight (liver, spleen, and kidney), perirenal fat pad and epididymal fat pad weights were measured. To examine Cd detoxification, urinary Cd excretion and metallothonein (MT) concentrations in kidney and intestine were measured. Food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weight and fat pad weights were decreased by dietary Cd intake. Urinary Cd excretion and MT concentrations in kidney and small intestine were increased by dietary Cd. After given Cd containing diet, food intake, calorie intake, body weight change, body weight gain/calorie intake, organ weights and fat pad weights were not influenced by dietary chlorella intake. Renal MT synthesis tended to be higher in a dose-dependent manner, but not significantly. And chlorella intake did not significantly facilitate renal and intestinal MT synthesis and urinary Cd excretion. These findings suggest that, after stopping cadmium supply, chlorella supplementation, regardless of its percentage, might not improve cadmium detoxification from the body in growing rats.

  11. Stable isotope and trace metal compositions of Australian prawns as a guide to authenticity and wholesomeness.

    Science.gov (United States)

    Carter, J F; Tinggi, U; Yang, X; Fry, B

    2015-03-01

    This research has explored the potential of stable isotope and trace metal profiles to distinguish Australian prawns from prawns imported from neighbouring Asian countries. Australian prawns were collected mostly from the Brisbane area. Strong differences in Australian vs. imported prawns were evident from both the isotope and trace element data, with the differences most likely occurring because imported prawns are typically reared in aquaculture facilities and frozen prior to sale in Australia. The aquaculture origins are characterised by comparatively; low δHVSMOW, δ(13)CVPDB values, low concentrations of arsenic, zinc and potassium, and high water contents (>80%). Relatively high arsenic and cadmium contents were found within Australian prawns, but the concentrations did not exceed local human health guidelines.

  12. Cadmium removal from contaminated soil by tunable biopolymers.

    Science.gov (United States)

    Prabhukumar, Giridhar; Matsumoto, Mark; Mulchandani, Ashok; Chen, Wilfred

    2004-06-01

    An elastin-like polypeptide (ELP) composed of a polyhistidine tail (ELPH12) was exploited as a tunable, metal-binding biopolymer with high affinity toward cadmium. By taking advantage of the property of ELPH12 to undergo a reversible thermal precipitation, easy recovery of the sequestered cadmium from contaminated water was demonstrated as the result of a simple temperature change. In this study, batch soil washing experiments were performed to evaluate the feasibility of using ELPH12 as an environmentally benign strategy for removing cadmium from contaminated soil. The stability constant (log KL) for the cadmium-ELPH12 complex was determined to be 6.8, a value similar to that reported for the biosurfactant rhamnolipid. Two washings with 1.25 mg/mL of ELPH12 were able to remove more than 55% of the bound cadmium as compared to only 8% removal with ELP containing no histidine tail or 21% removal using the same concentration of EDTA. Unlike rhamnolipid from Pseudomonas aeruginosa ATCC 9027, which adsorbs extensively to soil, less than 10% of ELPH12 was adsorbed under all soil washing conditions. As a result, a significantly lower concentration of ELPH12 (0.036 mM as compared to 5-10 mM of biosurfactants) was required to achieve similar extraction efficiencies. However, cadmium recovery by simple precipitation was incomplete due to the displacement of bound cadmium by zinc ions present in soil. Owing to its benign nature, ease of production, and selective tailoring of the metal binding domain toward any target metals of interest, ELP biopolymers may find utility as an effective extractant for heavy metal removal from contaminated soil or ore processing.

  13. Predictors of urinary cadmium levels in adult females

    Energy Technology Data Exchange (ETDEWEB)

    McElroy, Jane A. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States)]. E-mail: jamcelroy@wisc.edu; Shafer, Martin M. [University of Wisconsin, Environmental Chemistry and Technology Program, 600 N Park Street, Madison, WI 53706 (United States); Hampton, John M. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States); Newcomb, Polly A. [University of Wisconsin Paul P. Carbone Comprehensive Cancer Center, 610 Walnut Street, 370 WARF, Madison, WI 53726 (United States); Fred Hutchinson Cancer Research Center, Cancer Prevention Program, 1100 Fairview Ave N, M4-B402 PO Box 19024, Seattle, WA 98109 (United States)

    2007-09-01

    Ubiquitous exposure to low levels of cadmium has raised concern about adverse health effects. The aim of this study was to identify characteristics of non-occupationally exposed adult females that correlated with creatinine-adjusted urinary cadmium levels. In our population-based study, trained interviewers collected information from 254 female Wisconsin residents aged 20-69 years on tobacco use, limited dietary consumption patterns, reproductive history, demographics, and residential history. Participants provided spot-urine specimens collected at home. Urine cadmium concentrations were quantified using inductively-coupled plasma mass spectrometry and creatinine levels were also determined. Least square means and 95% confidence intervals for the natural log of the creatinine-adjusted urinary cadmium levels were calculated for each characteristic using multivariate analysis of variance adjusting for age and smoking status. Results were calculated on the log scale and then transformed to the original scale by taking the exponent of each of the values. We observed statistically significant increasing creatinine-adjusted urinary cadmium mean levels relative to smoking status, older age, parity, lower body surface area, mineral zinc supplement consumption, and high income. We did not observe a difference relative to consumption of organ meats, crustaceans, alcohol, multivitamins, multiminerals or homegrown vegetables, age of menopause, menarche of participant or oldest daughter, menopausal status or urban-rural residential location. Approximately 40% of the variance in creatinine-adjusted urinary cadmium levels in adult women was explained by several characteristics. Similar to other studies, age and smoking were the strongest determinants of creatinine-adjusted urinary cadmium concentration.

  14. Effect of Biochar on Relieving Cadmium Stress and Reducing Accumulation in Super japonica Rice

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhen-yu; MENG Jun; DANG Shu; CHEN Wen-fu

    2014-01-01

    It is of great importance to solve the threats induced by cadmium pollution on crops. This paper examined the effect of biochar on cadmium accumulation in japonica rice and revealed the mechanism underlying the response of protective enzyme system to cadmium stress. Biochar derived from rice straw was applied at two application rates under three cadmium concentrations. Shennong 265, super japonica rice variety, was selected as the test crop. The results indicated that cadmium content in above-ground biomass of rice increased with increasing soil cadmium concentrations, but the biochar application could suppress the accumulation of cadmium to some extent. Under high concentrations of cadmium, content of free proline and MDA (malondialdehyde) were high, so did the SOD (superoxide dismutase), POD (peroxidase) and CAT (catalase) activity in the lfag leaf of rice. However, the protective enzyme activities remained at low level when biochar was added.

  15. A cross-sectional survey of cadmium biomarkers and cigarette smoking.

    Science.gov (United States)

    Hecht, Eric M; Arheart, Kris; Lee, David J; Hennekens, Charles H; Hlaing, WayWay M

    2016-07-01

    Cadmium contamination of tobacco may contribute to the health hazards of cigarette smoking. The 2005-2012 United States National Health and Nutrition Examination Survey data provided a unique opportunity to conduct a cross-sectional survey of cadmium biomarkers and cigarette smoking. Among a sample of 6761 participants, we evaluated mean differences and correlations between cadmium biomarkers in the blood and urine and characteristics of never, former and current smokers. We found statistically significant differences in mean cadmium biomarker levels between never and former smokers as well as between never and current smokers. In current smokers, duration in years had a higher correlation coefficient with urinary than blood cadmium levels. In contrast, number of cigarettes smoked per day had a higher correlation coefficient with blood than urinary cadmium levels. These data suggest that blood and urine cadmium biomarker levels differ by duration and dose. These findings should be considered in evaluating any association between cadmium and smoking related diseases, especially cardiovascular disease.

  16. Distribution of Cadmium, Iron, and Zinc in Millstreams of Hard Winter Wheat (Triticum aestivum L.).

    Science.gov (United States)

    Guttieri, Mary J; Seabourn, Bradford W; Liu, Caixia; Baenziger, P Stephen; Waters, Brian M

    2015-12-16

    Hard winter wheat (Triticum aestivum L.) is a major crop in the Great Plains of the United States, and our previous work demonstrated that wheat genotypes vary for grain cadmium accumulation with some exceeding the CODEX standard (0.2 mg kg(-1)). Previous reports of cadmium distribution in flour milling fractions have not included high cadmium grain. This study measured the distribution of cadmium, zinc, and iron in flour and bran streams from high cadmium (0.352 mg kg(-1)) grain on a pilot mill that produced 12 flour and four bran streams. Recovery in flour was substantially greater for cadmium (50%) than for zinc (31%) or iron (22%). Cadmium, zinc, and iron in the lowest mineral concentration flour stream, representing the purest endosperm fraction, were 52, 22, and 11%, respectively, of initial grain concentration. Our results indicate that, relative to zinc and iron, a greater proportion of cadmium is stored in the endosperm, the source of white flour.

  17. Nuclear physics and stable isotopes; Physique nucleaire et isotopes stables

    Energy Technology Data Exchange (ETDEWEB)

    Goutte, D. [CEA Centre d`Etudes de Saclay, 91 - Gif-sur-Yvette (France). Dept. d`Astrophysique, de la Physique des Particules, de la Physique Nucleaire et de l`Instrumentation Associee

    1994-12-31

    The aim of this paper is to show that fundamental research in nuclear physics requires utilization of stable isotopes; stable isotopes are essential as target material since a large quantity of nucleus have to be studied in order to appreciate all the complexity of the nuclear structure, but also as a tool, such as beams, for the same purpose. Examples are given with samarium, tin and germanium isotopes. 7 figs.

  18. Accumulation and effects of cadmium on guppy (Poecilia reticulata) fed cadmium-dosed cladocera (Moina macrocopa)

    Energy Technology Data Exchange (ETDEWEB)

    Hatakeyama, S.; Yasuno, M.

    1982-08-01

    The study examines the rate of cadmium uptake and body burdens which cause adverse effects on the survival and growth of guppies when they are exposed to Cd dosed in zooplankton (Moina macrocopa) and Cd dissolved in water. Eight guppies fed Moina dosed at 20 ..mu..g Cd/L water died before 10 days. Growth of the remainder of the guppies exposed at this rate was impaired initially but was returned to control level around the 10th day of the study. (JMT)

  19. Distribution and formation of heavy metal elements in rice plants. I. Distribution of heavy metal elements in rice grains using an electron probe X-ray microanalyzer (EPMA)

    Energy Technology Data Exchange (ETDEWEB)

    Yoshikawa, T.; Kusaka, S.; Zikihara, T.; Yoshida, T.

    1977-01-01

    The distribution of minerals in the outer layer of rice grains was determined. Unpolished rice was polished using a rice-polishing machine and its bran was collected at specified intervals during the polishing. The bran comprised 6.5% of the whole grain by weight and contained the highest contents of cadmium, copper, and zinc. The contents of these metals in the bran after the first fraction, which comprised from 6.5% to 11.0% of the grain by weight, were lower than that of the surface fraction. An electron probe X-ray microanalyzer (EPMA) was used to determine the transversal microdistribution of cadmium, copper, and zinc in the outer layer of the grains. Cadmium was concentrated in the surface fraction and copper and zinc were concentrated in the aleurone layer of the rice grains.

  20. One-Probe Search

    DEFF Research Database (Denmark)

    Östlin, Anna; Pagh, Rasmus

    2002-01-01

    We consider dictionaries that perform lookups by probing a single word of memory, knowing only the size of the data structure. We describe a randomized dictionary where a lookup returns the correct answer with probability 1 - e, and otherwise returns don't know. The lookup procedure uses an expan...

  1. Endocavity Ultrasound Probe Manipulators.

    Science.gov (United States)

    Stoianovici, Dan; Kim, Chunwoo; Schäfer, Felix; Huang, Chien-Ming; Zuo, Yihe; Petrisor, Doru; Han, Misop

    2013-06-01

    We developed two similar structure manipulators for medical endocavity ultrasound probes with 3 and 4 degrees of freedom (DoF). These robots allow scanning with ultrasound for 3-D imaging and enable robot-assisted image-guided procedures. Both robots use remote center of motion kinematics, characteristic of medical robots. The 4-DoF robot provides unrestricted manipulation of the endocavity probe. With the 3-DoF robot the insertion motion of the probe must be adjusted manually, but the device is simpler and may also be used to manipulate external-body probes. The robots enabled a novel surgical approach of using intraoperative image-based navigation during robot-assisted laparoscopic prostatectomy (RALP), performed with concurrent use of two robotic systems (Tandem, T-RALP). Thus far, a clinical trial for evaluation of safety and feasibility has been performed successfully on 46 patients. This paper describes the architecture and design of the robots, the two prototypes, control features related to safety, preclinical experiments, and the T-RALP procedure.

  2. Probing the Solar System

    Science.gov (United States)

    Wilkinson, John

    2013-01-01

    Humans have always had the vision to one day live on other planets. This vision existed even before the first person was put into orbit. Since the early space missions of putting humans into orbit around Earth, many advances have been made in space technology. We have now sent many space probes deep into the Solar system to explore the planets and…

  3. Direct electrochemical stripping detection of cystic-fibrosis-related DNA linked through cadmium sulfide quantum dots

    Science.gov (United States)

    Marin, Sergio; Merkoçi, Arben

    2009-02-01

    Electrochemical detection of a cadmium sulfide quantum dots (CdS QDs)-DNA complex connected to paramagnetic microbeads (MB) was performed without the need for chemical dissolving. The method is based on dropping 20 µl of CdS QD-DNA-MB suspension on the surface of a screen-printed electrode. It is followed by magnetic collection on the surface of the working electrode and electrochemical detection using square-wave voltammetry (SWV), giving a well-shaped and sensitive analytical signal. A cystic-fibrosis-related DNA sequence was sandwiched between the two DNA probes. One DNA probe is linked via biotin-streptavidin bonding with MB and the other one via thiol groups with the CdS QD used as tags. Nonspecific signals of DNA were minimized using a blocking agent and the results obtained were successfully employed in a model DNA sensor with an interest in future applications in the clinical field. The developed nanoparticle biosensing system may offer numerous opportunities in other fields where fast, low cost and efficient detection of small volume samples is required.

  4. Femtosecond Transient Absorption Studies in Cadmium Selenide Nanocrystal Thin Films Prepared by Chemical Bath Deposition Method

    Directory of Open Access Journals (Sweden)

    M. C. Rath

    2007-01-01

    Full Text Available Dynamics of photo-excited carrier relaxation processes in cadmium selenide nanocrystal thin films prepared by chemical bath deposition method have been studied by nondegenerate femtosecond transient pump-probe spectroscopy. The carriers were generated by exciting at 400 nm laser light and monitored by several other wavelengths. The induced absorption followed by a fast bleach recovery observed near and above the bandgap indicates that the photo-excited carriers (electrons are first trapped by the available traps and then the trapped electrons absorb the probe light to show a delayed absorption process. The transient decay kinetics was found to be multiexponential in nature. The short time constant, <1 picosecond, was attributed to the trapping of electrons by the surface and/or deep traps and the long time constant, ≥20 picoseconds, was due to the recombination of the trapped carriers. A very little difference in the relaxation processes was observed in the samples prepared at bath temperatures from 25∘C to 60∘C.

  5. Nickel isotopes and methanogens

    Science.gov (United States)

    Neubeck, A.; Ivarsson, M.

    2013-12-01

    Methanogens require Ni for their growth and as a consequence the microbial fractionation of Ni isotopes can be used as a biomarker for activity of methanogenic communities1. Anaerobic laboratory experiments was performed using methanogens to investigate methanogenic growth in a modified nutrient media2 with olivine Fo91 (5g/l) added as an additional mineral nutrient source and as the only H2 provider. One of the investigated methanogens showed an increased growth in the experiments with added olivine. There were also a close relationship between the mobilized Ni and the growth of the methanogen. Ni is an element that previously has been neglected in the study of fossilized microorganisms and their interaction with mineral substrates and, thus, there are no records or published data of Ni in association with microfossils. However, we have detected enrichments of Ni in fossilized microorganisms and ichno-fossils, respectively, from three separate locations. Ni is not present in the host rock in any of the samples. Thus, Ni is present in association with fossilized microorganisms from environments and more extensive analysis is required to understand the magnitude, uptake, preservation and fractionation of Ni in microfossils. In order to analyze Ni isotope fractionation from microbe-mineral interaction, we plan to use a high-resolution Laser-Ablation Time-of-Flight Mass Spectrometer (LMS)3. In situ profile ablation will provide detailed and localized data on fractionation patterns between microfossils and their host rock. Also, this technique will allow us to identify the change in Ni isotopic fractionation in rock samples caused by abiotic and biogenic processes in a faster and easier way and with less risk for contamination compared to the wet chemistry analyses of Ni isotopes. 1. Cameron, V., Vance, D., Archer, C. & House, C. H. A biomarker based on the stable isotopes of nickel. Proceedings of the National Academy of Sciences 106, 10944-10948 (2009). 2. Schn

  6. Probing Site-Specific Structural Information of Peptides at Model Membrane Interface In Situ.

    Science.gov (United States)

    Ding, Bei; Panahi, Afra; Ho, Jia-Jung; Laaser, Jennifer E; Brooks, Charles L; Zanni, Martin T; Chen, Zhan

    2015-08-19

    Isotope labeling is a powerful technique to probe detailed structures of biological molecules with a variety of analytical methods such as NMR and vibrational spectroscopies. It is important to obtain molecular structural information on biological molecules at interfaces such as cell membranes, but it is challenging to use the isotope labeling method to study interfacial biomolecules. Here, by individually (13)C═(16)O labeling ten residues of a peptide, Ovispirin-1, we have demonstrated for the first time that a site-specific environment of membrane associated peptide can be probed by the submonolayer surface sensitive sum frequency generation (SFG) vibrational spectroscopy in situ. With the peptide associated with a single lipid bilayer, the sinusoidal trend of the SFG line width and peak-center frequency suggests that the peptide is located at the interface beneath the lipid headgroup region. The constructive interferences between the isotope labeled peaks and the main peptide amide I peak contributed by the unlabeled components were used to determine the membrane orientation of the peptide. From the SFG spectral peak-center frequency, line width, and polarization dependence of the isotope labeled units, we deduced structural information on individual units of the peptide associated with a model cell membrane. We also performed molecular dynamics (MD) simulations to understand peptide-membrane interactions. The physical pictures described by simulation agree well with the SFG experimental result. This research demonstrates the feasibility and power of using isotope labeling SFG to probe molecular structures of interfacial biological molecules in situ in real time.

  7. IM-CRDS for the analysis of matrix-bound water isotopes: a streamlined (and updated) tool for ecohydrologists to probe small-scale variability in plants Yasuhara, S. (syasuhara@picarro.com)1,Carter, J.A. (jcarter@picarro.com)1, Dennis, K.J. (kdennis@picarro.com)1 1Picarro Inc., 3105 Patrick Henry Drive, Santa Clara, CA 95054

    Science.gov (United States)

    Yasuhara, S.

    2013-12-01

    The ability to measure the isotopic composition of matrix-bound water is valuable to many facets of earth and environmental sciences. For example, ecohydrologists use stable isotopes of oxygen and hydrogen in plant and soil water, in combination with measurements of atmospheric water vapor, surface water and precipitation, to estimate budgets of evapotranspiration. Likewise, water isotopes of oceanic water, brines and other waters with high total dissolved solids (TDS, e.g., juices) are relevant to studying large-scale oceanic circulation, small-scale mixing, groundwater contamination, the balance of evaporation to precipitation, and the provenance of food. Conventionally matrix-bound water has been extracted using cryogenic distillation, whereby water is distilled from the material in question (e.g., a leaf sample) by heating under vacuum and collecting the resultant water vapor using liquid nitrogen. The water can then be analyzed for its stable isotopic composition by a variety of methods, including isotope ratio mass spectrometry and laser techniques, such as Cavity Ring-Down Spectroscopy (CRDS). Here we present recent improvements in an alternative, and stream-lined, solution for integrated sample extraction and isotopic measurement using a Picarro Induction Module (IM) coupled to commercially-available CRDS analyzer from Picarro. This technique is also valuable for waters with high TDS, which can have detrimental effects on flash vaporization process, typically used for the introduction of water to Picarro CRDS water isotope analyzers. The IM works by inductively heating a sample held within a metal sample holder in a glass vial flushed with dry air. Tested samples include leaves, stems, twigs, calibration water, juices, and salt water. The heating process evolves water vapor which is then swept through the system at approximately 150 standard cubic centimeters per minute. The evolved water vapor passes through an activated charcoal cartridge for removal of

  8. Chronic Cadmium Exposure Stimulates SDF-1 Expression in an ERα Dependent Manner

    OpenAIRE

    2013-01-01

    Cadmium is an omnipotent environmental contaminant associated with the development of breast cancer. Studies suggest that cadmium functions as an endocrine disruptor, mimicking the actions of estrogen in breast cancer cells and activating the receptor to promote cell growth. Although acute cadmium exposure is known to promote estrogen receptor-mediated gene expression associated with growth, the consequence of chronic cadmium exposure is unclear. Since heavy metals are known to bioaccumulate,...

  9. Cadmium Promotes Breast Cancer Cell Proliferation by Potentiating the Interaction between ERα and c-Jun

    OpenAIRE

    2010-01-01

    Cadmium is an environmental contaminant that enters the body through diet or cigarette smoke. It affects multiple cellular processes, including cell proliferation, differentiation, and apoptosis. Recently, cadmium has been shown to function as an endocrine disruptor, to stimulate estrogen receptor α (ERα) activity and promote uterine and mammary gland growth in mice. Although cadmium exposure has been associated with the development of breast cancer, the mechanism of action of cadmium remains...

  10. Potentiometric stripping analysis of lead and cadmium leaching from dental prosthetic materials and teeth

    OpenAIRE

    GORAN M. NIKOLIC; BILJANA M. KALICANIN; RUZICA S. NIKOLIC

    2004-01-01

    Potentiometric stipping analysis (PSA) was applied for the determination of lead and cadmium leaching from dental prosthetic materials and teeth. The soluble lead content in finished dental implants was found to be much lower than that of the individual components used for their preparation. Cadmium was not detected in dental implants and materials under the defined conditions. The soluble lead and cadmium content of teeth was slightly lower than the lead and cadmium content in whole teeth (w...

  11. Effect of Herbal Preparation on Heavy Metal (Cadmium) Induced Antioxidant System in Female Wistar Rats

    OpenAIRE

    2011-01-01

    Cadmium is one of the elements found to damage antioxidant systems in mammals. To ameliorate cadmium toxicity and to prevent oxidative stress, natural products may be useful. In Indian ethnobotanical practice, a mixture of 17 herbal products is used to fortify the reproductive system of women after parturition and to reverse ovarian oxidative stress. Oral administration of this extract to rats exposed to cadmium was useful in reversing oxidative stress. Two different doses of cadmium (50 ppm ...

  12. A method for making a cadmium anode for a hermetically sealed alkaline storage battery

    Energy Technology Data Exchange (ETDEWEB)

    Morioka, Y.; Yosikhira, Y.

    1983-07-14

    Metallic cadmium powder and a glue solution are added to CdO powder. The compound is applied to a current tap and dried. The powder form metallic cadmium is prepared from a mixture of zinc and nickel powder which is dispersed in a solution of cadmium salts. As a result of the replacement reaction, a spongy metallic cadmium is produced which contains nickel. The sponge is ground. The obtained powder is used as an additive for the CdO.

  13. Elemental and iron isotopic composition of aerosols collected in a parking structure.

    Science.gov (United States)

    Majestic, Brian J; Anbar, Ariel D; Herckes, Pierre

    2009-09-01

    The trace metal contents and iron isotope composition of size-resolved aerosols were determined in a parking structure in Tempe, AZ, USA. Particulate matter (PM)2.5 microm were collected. Several air toxics (e.g., arsenic, cadmium, and antimony) were enriched above the crustal average, implicating automobiles as an important source. Extremely high levels of fine copper (up to 1000 ng m(-3)) were also observed in the parking garage, likely from brake wear. The iron isotope composition of the aerosols were found to be +0.15+/-0.03 per thousand and +0.18+/-0.03 per thousand for the PM2.5 microm fractions, respectively. The similarity of isotope composition indicates a common source for each size fraction. To better understand the source of iron in the parking garage, the elemental composition in four brake pads (two semi-metallic and two ceramic), two tire tread samples, and two waste oil samples were determined. Striking differences in the metallic and ceramic brake pads were observed. The ceramic brake pads contained 10-20% copper by mass, while the metallic brake pads contained about 70% iron, with very little copper. Both waste oil samples contained significant amounts of calcium, phosphorous, and zinc, consistent with the composition of some engine oil additives. Differences in iron isotope composition were observed between the source materials; most notably between the tire tread (average=+0.02 per thousand) and the ceramic brake linings (average=+0.65 per thousand). Differences in isotopic composition were also observed between the metallic (average=+0.18 per thousand) and ceramic brake pads, implying that iron isotope composition may be used to resolve these sources. The iron isotope composition of the metallic brake pads was found to be identical to the aerosols, implying that brake dust is the dominant source of iron in a parking garage.

  14. C12/C13-ratio determination in nanodiamonds by atom-probe tomography.

    Science.gov (United States)

    Lewis, Josiah B; Isheim, Dieter; Floss, Christine; Seidman, David N

    2015-12-01

    The astrophysical origins of ∼ 3 nm-diameter meteoritic nanodiamonds can be inferred from the ratio of C12/C13. It is essential to achieve high spatial and mass resolving power and minimize all sources of signal loss in order to obtain statistically significant measurements. We conducted atom-probe tomography on meteoritic nanodiamonds embedded between layers of Pt. We describe sample preparation, atom-probe tomography analysis, 3D reconstruction, and bias correction. We present new data from meteoritic nanodiamonds and terrestrial standards and discuss methods to correct isotopic measurements made with the atom-probe tomograph.

  15. Therapeutic use of radioactive isotopes

    CERN Multimedia

    Caroline Duc

    2013-01-01

    In December, researchers from ISOLDE-CERN, the Paul Scherrer Institute (PSI) and the Institut Laue-Langevin (ILL) published the results of an in vivo study which successfully proved the effectiveness of four terbium isotopes for diagnosing and treating cancerous tumours.   Four terbium isotopes suitable for clinical purposes. “ISOLDE is the only installation capable of supplying terbium isotopes of such purity and intensity in the case of three out of the four types used in this study,” explains Karl Johnson, a physicist at ISOLDE.  “Producing over a thousand different isotopes, our equipment offers the widest choice of isotopes in the world!” Initially intended for fundamental physics research, ISOLDE has diversified its activities over time to invest in various projects in the materials science, biochemistry and nuclear medicine fields. The proof-of-concept study has confirmed that the four terbium isotopes 149Tb, 152Tb, 155Tb produ...

  16. Nrf2 activation prevents cadmium-induced acute liver injury

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Kai C. [Department of Pharmacology, Toxicology, and Therapeutics, University of Kansas Medical Center, Kansas City, KS (United States); Liu, Jie J. [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States); Klaassen, Curtis D., E-mail: cklaasse@kumc.edu [Department of Internal Medicine, University of Kansas Medical Center, Kansas City, KS (United States)

    2012-08-15

    Oxidative stress plays an important role in cadmium-induced liver injury. Nuclear factor erythroid 2-related factor 2 (Nrf2) is a transcription factor that up-regulates cytoprotective genes in response to oxidative stress. To investigate the role of Nrf2 in cadmium-induced hepatotoxicity, Nrf2-null mice, wild-type mice, kelch-like ECH-associated protein 1-knockdown (Keap1-KD) mice with enhanced Nrf2, and Keap1-hepatocyte knockout (Keap1-HKO) mice with maximum Nrf2 activation were treated with cadmium chloride (3.5 mg Cd/kg, i.p.). Blood and liver samples were collected 8 h thereafter. Cadmium increased serum alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) activities, and caused extensive hepatic hemorrhage and necrosis in the Nrf2-null mice. In contrast, Nrf2-enhanced mice had lower serum ALT and LDH activities and less morphological alternations in the livers than wild-type mice. H{sub 2}DCFDA (2′,7′-dichlorodihydrofluoresein diacetate) staining of primary hepatocytes isolated from the four genotypes of mice indicated that oxidative stress was higher in Nrf2-null cells, and lower in Nrf2-enhanced cells than in wild-type cells. To further investigate the mechanism of the protective effect of Nrf2, mRNA of metallothionein (MT) and other cytoprotective genes were determined. Cadmium markedly induced MT-1 and MT-2 in livers of all four genotypes of mice. In contrast, genes involved in glutathione synthesis and reducing reactive oxygen species, including glutamate-cysteine ligase (Gclc), glutathione peroxidase-2 (Gpx2), and sulfiredoxin-1 (Srxn-1) were only induced in Nrf2-enhanced mice, but not in Nrf2-null mice. In conclusion, the present study shows that Nrf2 activation prevents cadmium-induced oxidative stress and liver injury through induction of genes involved in antioxidant defense rather than genes that scavenge Cd. -- Highlights: ► Cadmium caused extensive hepatic hemorrhage and necrosis in Nrf2-null mice. ► Keap1-KD and Keap1-HKO mice

  17. EDITORIAL: Probing the nanoworld Probing the nanoworld

    Science.gov (United States)

    Miles, Mervyn

    2009-10-01

    In nanotechnology, it is the unique properties arising from nanometre-scale structures that lead not only to their technological importance but also to a better understanding of the underlying science. Over the last twenty years, material properties at the nanoscale have been dominated by the properties of carbon in the form of the C60 molecule, single- and multi-wall carbon nanotubes, nanodiamonds, and recently graphene. During this period, research published in the journal Nanotechnology has revealed the amazing mechanical properties of such materials as well as their remarkable electronic properties with the promise of new devices. Furthermore, nanoparticles, nanotubes, nanorods, and nanowires from metals and dielectrics have been characterized for their electronic, mechanical, optical, chemical and catalytic properties. Scanning probe microscopy (SPM) has become the main characterization technique and atomic force microscopy (AFM) the most frequently used SPM. Over the past twenty years, SPM techniques that were previously experimental in nature have become routine. At the same time, investigations using AFM continue to yield impressive results that demonstrate the great potential of this powerful imaging tool, particularly in close to physiological conditions. In this special issue a collaboration of researchers in Europe report the use of AFM to provide high-resolution topographical images of individual carbon nanotubes immobilized on various biological membranes, including a nuclear membrane for the first time (Lamprecht C et al 2009 Nanotechnology 20 434001). Other SPM developments such as high-speed AFM appear to be making a transition from specialist laboratories to the mainstream, and perhaps the same may be said for non-contact AFM. Looking to the future, characterisation techniques involving SPM and spectroscopy, such as tip-enhanced Raman spectroscopy, could emerge as everyday methods. In all these advanced techniques, routinely available probes will

  18. Lithium isotope separation by laser

    Energy Technology Data Exchange (ETDEWEB)

    Arisawa, T.; Maruyama, Y.; Suzuki, Y.; Shiba, K.

    1982-01-01

    A lithium isotope separation was performed using a laser isotope separation method. It was found that the lithium atoms with a natural isotopic abundance enhanced its /sup 6/Li concentration up to over 90% by tuning the laser wavelength to the /sup 2/Psub(1/2) of /sup 6/Li. Too high power, however, leads to a loss of enrichment due to the power broadening effect which was analysed by the equation of motion of density matrices.

  19. Subcellular Localization of Cadmium in Chlorella vulgaris Beijerinck Strain Bt-09

    Directory of Open Access Journals (Sweden)

    P.B. Lintongan

    2004-06-01

    Full Text Available Growth response curves of Chlorella vulgaris Beijerinck strain Bt-09 to sublethal concentrations of cadmium were evaluated. The growth responses of this microalgal isolate was determined through analysis of chlorophyll a levels. Cadmium was effectively taken up by the cells as determined by Flame Atomic Absorption Spectrophotometry (F-AAS. Subcellular fractionation was undertaken to locate sites that accumulate cadmium.

  20. Effects of chronic alternating cadmium exposure on the episodic secretion of prolactin in male rats

    Energy Technology Data Exchange (ETDEWEB)

    Esquifino, A.I. [Madrid Univ. (Spain). Facultad de Medicina Complutense; Marquez, N.; Alvarez-Demanuel, E.; Lafuente, A. [Vigo Univ., Orense (Spain). Lab. de Toxicologia

    1998-07-01

    Cadmium increases or decreases prolactin secretion depending on the dose and duration of the exposure to the metal. However, whether there are cadmium effects on the episodic prolactin secretion is less well known. This study was undertaken to address whether chronic alternating exposure to two different doses of cadmium affects the episodic pattern of prolactin and to what extent the effects of cadmium are age-dependent. Male rats were treated s.c. with cadmium chloride (0.5 or 1.0 mg/kg) from day 30 to 60, or from day 60 to 90 of age, with alteration of the doses every 4 days, starting with the smaller dose. Controls received vehicle every 4 days. The last dose of cadmium was given 48 h prior to the pulsatility study. Prolactin secretion in the 4 experimental groups studied was episodic and changed significantly after cadmium exposure. Cadmium administration from day 30 to 60 of life significantly decreased the mean half-life of prolactin. On the other hand, when administered from day 60 to 90 cadmium significantly decreased the mean as well as serum prolactin levels and the absolute amplitude of the prolactin pulses, their duration, the relative amplitude or the mean half-life of the hormone. The frequency of prolactin peaks was not changed by cadmium administration. The results indicate that low intermittent doses of cadmium chronically administered change the episodic secretion pattern of prolactin in rats. The effects of cadmium on prolactin secretion were age dependent. (orig.)

  1. Effects of diethyldithiocarbamate on the toxicokinetics of cadmium chloride in mice

    DEFF Research Database (Denmark)

    Andersen, O; Nielsen, J B

    1989-01-01

    in the toxicokinetics of cadmium induced by DDC are mainly due to the high cadmium doses employed and the intraperitoneal administration of DDC. At lower doses and more realistic administration routes for cadmium and DDC, the effect of DDC is less. However, still DDC does not seem to have any potential as an antidote...

  2. SNF1-related protein kinases type 2 are involved in plant responses to cadmium stress.

    NARCIS (Netherlands)

    A. Kulik; A. Anielska-Mazur; M. Bucholc; E. Koen; E. Szymańska; A. Żmieńko; E. Krzywińska; I. Wawer; F. McLoughlin; D. Ruszkowski; M. Figlerowicz; C. Testerink; A. Sklodowska; D. Wendehenne; G. Dobrowolska

    2012-01-01

    Cadmium ions are notorious environmental pollutants. To adapt to cadmium-induced deleterious effects plants have developed sophisticated defense mechanisms. However, the signaling pathways underlying the plant response to cadmium are still elusive. Our data demonstrate that SnRK2s (for SNF1-related

  3. Critical organ concentration of cadmium in occupationally-exposed workers

    Energy Technology Data Exchange (ETDEWEB)

    Ellis, K.J.; Morgan, W.D.; Yasumura, S.; Vartsky, D.; Zanzi, I.; Cohn, S.H.

    1981-01-01

    This report describes the present Brookhaven facility for in vivo measurements of cadmium in man and provides a comparison with other portable systems. The cadmium detection limits are 2.2 mg in the kidney and 1.5 ppM in the liver for the Brookhaven system. In a recent field study, the cadmium content of the left kidney and concentration in the liver were measured in 82 occupationally exposed workers and 10 control subjects. Organ content ranged up to 57 mg in the kidney and up to 120 ppM in the liver for the industrial group. By contrast, the values for the control group ranged from 0.4 to 11.8 mg for the kidney and 0.7 to 7.9 ppM for the liver. The geometric means were 3.7 mg for the kidney and 2.7 ppM for the liver in the control group. When the data were analyzed to provide an estimate of the critical concentration for the kidney, a range of 300 to 400 ..mu..g/g for the renal cortex was calculated. The corresponding cadmium concentrations in the liver and urine were 30 to 42 ppM (liver) and 22 to 28 ..mu..g/g creatinine (urine), respectively. Blood and urine levels of cadmium and ..beta../sub 2/-microgloubin were also evaluated as possible biological indicators of organ content.

  4. Cadmium toxicity in the thyroid gland of pregnant rats

    Energy Technology Data Exchange (ETDEWEB)

    Yoshizuka, M.; Mori, N.; Hamasaki, K.; Tanaka, I.; Yokoyama, M.; Hara, K.; Doi, Y.; Umezu, Y.; Araki, H.; Sakamoto, Y. (Department of Anatomy, School of Medicine, University of Occupational and Environmental Health, Kitakyushu (Japan))

    1991-08-01

    The toxic effects of cadmium on the thyroid gland of pregnant rats were studied with an electron microscope and an X-ray microanalyzer. Serum levels of thyroid hormones (T3 and T4) were also analyzed. Deterioration of the rough-surfaced endoplasmic reticulum occurred in the thyroid follicular epithelium on the fifth day of cadmium treatment. Large intracellular vacuoles, which arose from dilated cisternae of the rough-surfaced endoplasmic reticulum, were fused together, and marked swelling of the mitochondria was also noted. Thyroglobulin-secreting granules at the apical cytoplasm were decreased in number. By energy dispersive X-ray microanalysis, cadmium peaks were preferentially obtained from swollen mitochondria in the follicular epithelial cells. Serum levels of T3 and T4 were significantly decreased in cadmium-treated rats dams when compared to those of controls. In the present experiment, cycloheximide also caused degenerative changes in the rough-surfaced endoplasmic reticulum and the disappearance of thyroglobulin-secreting granules. Cycloheximide is a known inhibitor of protein synthesis on cytosolic ribosomes. These results indicated that accumulated cadmium in the mitochondria of thyroid follicular epithelial cells might disturb the oxidative phosphorylation of this organelle and the loss of energy supply possibly caused the inhibition of the synthesis and release of thyroid hormones.

  5. Lead and cadmium in indoor air and the urban environment

    Energy Technology Data Exchange (ETDEWEB)

    Komarnicki, Guenter J.K. [Department of Ecotoxicology, Center of Public Health, Medical University of Vienna, Waehringer Str. 10, A-1090 Vienna (Austria)]. E-mail: guenter.komarnicki@meduniwien.ac.at

    2005-07-15

    The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM{sub 10}, and PM{sub 2.5} were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM{sub 2.5}, both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality. - Urban vegetation and isopods are potential indicators for indoor aerial heavy metals.

  6. Cadmium block of isometric contractions of isolated bullfrog atrial cells.

    Science.gov (United States)

    Shepherd, N; Kavaler, F; Spielman, W

    1991-02-01

    We studied the effect of cadmium, verapamil, and quinacrine on the force of contraction (Fp) of isolated, single, field-stimulated bullfrog atrial cells. All agents were applied or removed rapidly (t1/2 approximately 15 ms) to minimize intracellular concentration changes other than intracellular calcium concentration. Two components of twitch force were observed, one blocked by micromolar Cd2+ and the other by millimolar Cd2+. The two contributed about equally to the activation of the twitch. The "cadmium-sensitive" portion of force (that affected by [Cd] less than or equal to 100 microM) had a K1/2 approximately 1 microM, was identical in magnitude to, and not additive with, a "verapamil-sensitive" (10 microM) component of force, was most strongly affected by 50-ms pulses of Cd2+ when they were applied in the mechanical latent period, and was potentiated by catecholamines. The cadmium-insensitive portion of force was abolished by the removal of extracellular calcium and was greatly potentiated by quinacrine (3 or 10 microM), a blocker of Na-Ca exchange. The results are consistent with the idea that activating calcium enters the cell via both an inactivating cadmium-sensitive L-type channel and a noninactivating cadmium-insensitive mechanism that is not Na-Ca exchange and leaves the cell via Na-Ca exchange.

  7. Lead and cadmium in indoor air and the urban environment.

    Science.gov (United States)

    Komarnicki, Günter J K

    2005-07-01

    The present study was conducted to find potential terrestrial biomonitors for heavy metals in indoor air in an urban environment. TSP, PM(10), and PM(2.5) were collected in three retirement facilities in the urban area of Vienna. In addition, particulate matter and soil, vegetation, and isopods (Porcellio scaber L.) were collected in the adjacent garden areas. Aerosols were sampled with a low-volume air sampler. The sampled materials were wet ashed and total lead and cadmium contents were determined. Water-soluble heavy metal concentrations were measured in aqueous extracts from air exposed filters, soil, and vegetation. Lead and cadmium were analyzed by graphite furnace AAS. Lead contents in the vegetation were inferred from water-soluble lead in soils. Lead in isopods generally reflected the contents in vegetation. Cadmium in plants probably derived from soil solutions as well as from atmospheric input. Isopods reflected the total cadmium contents in soils. Particulate matter was dominated by PM(2.5), both with respect to mass concentrations and to heavy metal contents. The indoor aerosol was found to be influenced by human activity, indoor sources, and outdoor particles. Relationships between indoor airborne heavy metals and the contents in vegetation (lead and cadmium: positive) and isopods (lead: negative) were identified to have the potential for biomonitoring indoor air quality.

  8. Cadmium in insects after ash fertilization

    Institute of Scientific and Technical Information of China (English)

    Martin Lodenius; Jussi Josefsson; Kari Heli(o)vaara; Esa Tulisalo; Matti Nummelin

    2009-01-01

    Ash fertilization of forests returns nutrients to forest ecosystems and has a positive effect on soil pH.but it also may elevate Cd concentrations of forest biota.Cadmium concentrations of some forest insects(Formica ants.carabids and Coleopteran larvac from decaying wood)were investigated in southern Finland where two plots were fertilized with wood ash,while two other plots represented anfertilized control plots.In ants,mean Cd concentration was 3.6±1.4 mg/kg.with nest workers having significantly higher concen-trations than workers trapped in pitfall traps.Concentrations at fertilized and unfertilized plots were similar.In carabid beetles,the average Cd concentration of Carabus glabratus was 0.44±0.36 mg/kg.with no significant difference between control plots and fertilized plots.In another carabid beetle,Pterostichus niger,mean Cd concentration was higher at fertilized plots compared to control plots.We conclude that the variation of Cd concentra-tions in the insects studied is more efficiently controlled by species-specific differences than fertilization history of the forest floor.

  9. Cadmium potentiates toxicity of cypermethrin in zebrafish.

    Science.gov (United States)

    Yang, Ye; Ye, Xiaoqing; He, Buyuan; Liu, Jing

    2016-02-01

    Co-occurrence of pesticides such as synthetic pyrethroids and metals in aquatic ecosystems raises concerns over their combined ecological effects. Cypermethrin, 1 of the top 5 synthetic pyrethroids in use, has been extensively detected in surface water. Cadmium (Cd) has been recognized as 1 of the most toxic metals and is a common contaminant in the aquatic system. However, little information is available regarding their joint toxicity. In the present study, combined toxicity of cypermethrin and Cd and the underlying mechanisms were investigated. Zebrafish embryos and adults were exposed to the individual contaminant or binary mixtures. Co-exposure to cypermethrin and Cd produced synergistic effects on the occurrence of crooked body, pericardial edema, and noninflation of swim bladder. The addition of Cd significantly potentiated cypermethrin-induced spasms and caused more oxidative stress in zebrafish larvae. Cypermethrin-mediated induction of transcription levels and catalytic activities of cytochrome P450 (CYP) enzyme were significantly down-regulated by Cd in both zebrafish larvae and adults. Chemical analytical data showed that in vitro elimination of cypermethrin by CYP1A1 was inhibited by Cd. The addition of Cd caused an elevation of in vivo cypermethrin residue levels in the mixture-exposed adult zebrafish. These results suggest that the enhanced toxicity of cypermethrin in the presence of Cd results from the inhibitory effects of Cd on CYP-mediated biotransformation of this pesticide. The authors' findings provide a deeper understanding of the mechanistic basis accounting for the joint toxicity of cypermethrin and Cd.

  10. Optical Constants of Cadmium Telluride Thin Film

    Science.gov (United States)

    Nithyakalyani, P.; Pandiaraman, M.; Pannir, P.; Sanjeeviraja, C.; Soundararajan, N.

    2008-04-01

    Cadmium Telluride (CdTe) is II-VI direct band gap semiconductor compound with potential application in Solar Energy conversion process. CdTe thin film of thickness 220 mn was prepared by thermal evaporation technique at a high vacuum better than 10-5 m.bar on well cleaned glass substrates of dimensions (l cm×3 cm). The transmittance spectrum and the reflectance spectrum of the prepared CdTc thin film was recorded using UV-Vis Spectrophotometer in the wavelength range between 300 nm and 900 nm. These spectral data were analyzed and the optical band and optical constants of CdTe Thin film have been determined by adopting suitable relations. The optical band gap of CdTe thin film is found to be 1.56 eV and this value is also agreeing with the published works of CdTe thin film prepared by various techniques. The absorption coefficient (α) has been higher than 106 cm-1. The Refractive index (n) and the Extinction Coefficient (k) are found to be varying from 3.0 to 4.0 and 0.1 Cm-1 to 0.5 Cm-1 respectively by varying the energy from l.0 eV to 4.0 eV. These results are also compared with the literature.

  11. LEACHING OF CADMIUM, TELLURIUM AND COPPER FROM CADMIUM TELLURIDE PHOTOVOLTAIC MODULES.

    Energy Technology Data Exchange (ETDEWEB)

    FTHENAKIS,V.

    2004-02-03

    Separating the metals from the glass is the first step in recycling end-of-life cadmium telluride photovoltaic modules and manufacturing scrap. We accomplished this by leaching the metals in solutions of various concentrations of acids and hydrogen peroxide. A relatively dilute solution of sulfuric acid and hydrogen peroxide was found to be most effective for leaching cadmium and tellurium from broken pieces of CdTe PV modules. A solution comprising 5 mL of hydrogen peroxide per kg of PV scrap in 1 M sulfuric acid, gave better results than the 12 mL H{sub 2}O{sub 2}/kg, 3.2 M H{sub 2}SO{sub 4} solution currently used in the industry. Our study also showed that this dilute solution is more effective than hydrochloric-acid solutions and it can be reused after adding a small amount of hydrogen peroxide. These findings, when implemented in large-scale operation, would result in significant savings due to reductions in volume of the concentrated leaching agents (H{sub 2}SO{sub 4} and H{sub 2}O{sub 2}) and of the alkaline reagents required to neutralize the residuals of leaching.

  12. Calibration Fixture For Anemometer Probes

    Science.gov (United States)

    Lewis, Charles R.; Nagel, Robert T.

    1993-01-01

    Fixture facilitates calibration of three-dimensional sideflow thermal anemometer probes. With fixture, probe oriented at number of angles throughout its design range. Readings calibrated as function of orientation in airflow. Calibration repeatable and verifiable.

  13. Growth and characterization of pure and Cadmium chloride doped KDP Crystals grown by gel medium

    Science.gov (United States)

    Kalaivani, M. S.; Asaithambi, T.

    2016-10-01

    Crystal growth technology provides an important basis for many industrial branches. Crystals are the unrecognized pillars of modern technology. Without crystals, there is no electronic industry, no photonic industry, and no fiber optic communications. Single crystals play a major role and form the strongest base for the fast growing field of engineering, science and technology. Crystal growth is an interdisciplinary subject covering physics, chemistry, material science, chemical engineering, metallurgy, crystallography, mineralogy, etc. In past few decades, there has been a keen interest on crystal growth processes, particularly in view of the increasing demand of materials for technological applications. Optically good quality pure and metal doped KDP crystals have been grown by gel method at room temperature and their characterization have been studied. Gel method is a much uncomplicated method and can be utilized to synthesize crystals which are having low solubility. Potassium dihydrogen orthophosphate KH2PO4 (KDP) continues to be an interesting material both academically and industrially. KDP is a representative of hydrogen bonded materials which possess very good electro - optic and nonlinear optical properties in addition to interesting electrical properties. Due to this interesting properties, we made an attempt to grow pure and cadmium chloride doped KDP crystals in various concentrations (0.002, 0.004, 0.006, 0.008 and 0.010) using gel method. The grown crystals were collected after 20 days. We get crystals with good quality and shaped. The dc electrical conductivity (resistance, capacitance and dielectric constant) values were measured at frequencies in the range of 1 KHZ and 100 HZ of pure and cadmium chloride added crystal with a temperature range of 400C to 1300C using simple two probe setup with Q band digital LCR meter present in our lab. The electrical conductivity increases with increase of temperature. The dielectric constants of metal doped KDP

  14. Cadmium accumulation characteristics and removal potentials of high cadmium accumulating rice line grown in cadmium-contaminated soils.

    Science.gov (United States)

    Tang, Hao; Li, Tingxuan; Yu, Haiying; Zhang, Xizhou

    2016-08-01

    Phytoextraction is a promising technique to remove cadmium (Cd) from contaminated soils. In this research, the two different Cd accumulation rice lines of Lu527-8 (the high Cd accumulating rice line) and Lu527-4 (the normal rice line) were grown in soils with different Cd treatments (0, 5, 10, and 20 mg kg(-1) soil) to evaluate Cd accumulation characteristics and Cd removal potentials. When the concentration of Cd in soil increased, Lu527-8 showed less symptoms of phytotoxicity when compared to Lu527-4. Furthermore, Lu527-8 demonstrated greater shoot Cd accumulation (321.17-964.95 mg plant(-1)) than Lu527-4 (50.37-201.66 μg plant(-1)) at the jointing and filling stages. The soil available Cd content of Lu527-8 significantly decreased by 26.92-38.97 and 27.77-63.44 % at the jointing and filling stages, respectively. Meanwhile, the total Cd content in soil also reduced by 11.64-46.75 and 21.41-54.11 % at jointing and filling stages, respectively. When the Cd concentration in soil was 20 mg kg(-1), the Cd extraction rate in shoots of Lu527-8 reached 2.12 and 2.85 % which increased 10.60 and 6.48 times compared with that of Lu527-4 at the jointing and filling stages, respectively. In conclusion, this study demonstrates that Lu527-8 shows great abilities of Cd accumulation and Cd removal potential from contaminated soils with different Cd treatments and it is a promising species for phytoextraction of Cd-contaminated soils.

  15. Cold regions isotope applications

    Energy Technology Data Exchange (ETDEWEB)

    Perrigo, L.D.; Divine, T.E.

    1976-04-01

    Pacific Northwest Laboratories (PNL) started the Cold Regions Isotope Applications Program in FY-1975 to identify special conditions in the Arctic and similar geographic areas (Cold Regions) where radioisotope power, heater, or sterilization systems would be desirable and economically viable. Significant progress was made in the first year of this program and all objectives for this initial 12-month period were achieved. The major conclusions and recommendations resulting for this effort are described below. The areas of interest covered include: radiosterilization of sewage; heating of septic tanks; and radioisotope thermoelectric generators as power sources for meteorological instruments and navigational aids. (TFD)

  16. Probing properties of cold radiofrequency plasma with polymer probe

    Science.gov (United States)

    Bormashenko, E.; Chaniel, G.; Multanen, V.

    2015-01-01

    The probe intended for the characterization of cold plasma is introduced. The probe allows the estimation of Debye length of cold plasma. The probe is based on the pronounced modification of surface properties (wettability) of polymer films by cold plasmas. The probe was tested with the cold radiofrequency inductive air plasma discharge. The Debye length and the concentration of charge carriers were estimated for various gas pressures. The reported results coincide reasonably with the corresponding values established by other methods. The probe makes possible measurement of characteristics of cold plasmas in closed chambers.

  17. Probing Properties of Cold Radiofrequency Plasma with Polymer Probe

    CERN Document Server

    Bormashenko, Edward; Multanen, Victor

    2014-01-01

    The probe intended for the characterization of cold plasma is introduced. The probe allows estimation of the Debye length of the cold plasma. The probe is based on the pronounced modification of surface properties (wettability) of polymer films by cold plasmas. The probe was tested with the cold radiofrequency inductive air plasma discharge. The Debye length and the concentration of charge carriers were estimated for various gas pressures. The reported results coincide reasonably with the corresponding values established by other methods. The probe makes possible measurement of characteristics of cold plasmas in closed chambers.

  18. Phoenix Conductivity Probe

    Science.gov (United States)

    2008-01-01

    This image taken by the Surface Stereo Imager on Sol 49, or the 49th Martian day of the mission (July 14, 2008), shows thermal and electrical conductivity probe on NASA's Phoenix Mars Lander's Robotic Arm. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is led by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  19. Analysis Of The Underpotential Deposition Of Cadmium On Copper

    Directory of Open Access Journals (Sweden)

    Kowalik R.

    2015-09-01

    Full Text Available In this study the process of deposition of cadmium on polycrystalline copper electrode in sulfate solution was investigated. The process of underpotential and bulk deposition was analyzed by classical electrochemical method: cyclic voltammetry(CV, anodic stripping voltammetry(ASV and electrochemical quartz crystal microbalance(EQCM. The obtained results were compared with electrochemical impedance spectroscopy(EIS measurements. CV, EQCM and EIS results suggest that the UPD of cadmium starts below potential −0.4 V vs Ag/AgCl. Additionally the stripping analysis indicates the formation of cadmium monolayer with different density of deposited atoms depending on the applied potential. The transition from UPD to bulk deposition occurs below potential −0,7 V.

  20. Cadmium extraction from phosphate ore. Effect of microwave

    Directory of Open Access Journals (Sweden)

    Zahia Benredjem

    2016-09-01

    Full Text Available This study discusses the operating variables for removal of cadmium from phosphate ore using Na2EDTA. These variables include the reaction time, Na2EDTA concentration, liquid/phosphate ore ratio, number of extractions and microwave extraction. Na2EDTA induced a two-step extraction process including a rapid extraction within the first hour, and a subsequent gradual release that occurred over the following hours. The cadmium extraction efficiency increased progressively with the increasing of Na2EDTA concentration. The extraction efficiency of cadmium increased with increasing liquid/phosphate ratio in the 5–200 range. Consecutive extractions using low concentrations were more effective than a single soil extraction with concentrated Na2EDTA. Microwave was beneficial to improve the removal in soil washing, and using microwave could partly substitute for agitation.

  1. Cadmium levels in Europe: implications for human health.

    Science.gov (United States)

    Pan, Jilang; Plant, Jane A; Voulvoulis, Nikolaos; Oates, Christopher J; Ihlenfeld, Christian

    2010-02-01

    In this study we used the Forum of European Geological Surveys geochemical baseline data to examine the distribution of cadmium (Cd) in Europe, with a particular reference to the international soil and water guideline values. The highest cadmium levels were found to occur in topsoil and to follow closely the distribution of P(2)O(5), suggesting that the contamination was from the use of rock phosphate fertilizer in intensive arable agriculture. In terms of human health impacts, food (up to several hundred microg/day) was found as the only major route of exposure to Cd for the non-smoking general population. It appeared that low levels of chronic exposure to Cd resulted in completely different human health impacts than those high levels that had caused the 'itai-itai' disease. Some correlations were suggested between cadmium levels and the age-adjusted prostate or breast cancer rates distributed in the European countries under study.

  2. Biosorption of Cadmium by Fungal Biomass of Aspergillus niger

    Institute of Scientific and Technical Information of China (English)

    QI YANG; JIAN-LONG WANG; ZHI XING

    2005-01-01

    Objective To investigate the removal of cadmium from aqueous solution by waste fungal biomass of Aspergillus niger, originated from citric acid fermentation industry. Methods Batch adsorption test was used to study the biosorption equilibrium and isotherm. The Cd2+ concentration was measured with atomic adsorption spectrophotometer (AAS) HITACHI 180-80. Results The biosorption achieved equilibrium within 30 min. The adsorption isotherm could be described by Freundlich adsorption model, and the constants KF and 1/n were determined to be 2.07 and 0.18, respectively, and the correlation efficiency was 0.97. The optimal pH for Cd adsorption was 6.0. The cadmium-laden biomass could be effectively regenerated using 0.1 N HCl. Conclusion The waste biomass of Aspergillus niger, a by-product of fermentation industry, is a potential biosorbent for the removal of cadmium from aqueous solution.

  3. Renal and blood pressure effects from environmental cadmium exposure in Thai children

    Energy Technology Data Exchange (ETDEWEB)

    Swaddiwudhipong, Witaya, E-mail: swaddi@hotmail.com [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Mahasakpan, Pranee [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Jeekeeree, Wanpen [Department of Medical Technology, Mae Sot General Hospital, Tak 63110 (Thailand); Funkhiew, Thippawan [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand); Sanjum, Rungaroon; Apiwatpaiboon, Thitikarn [Department of Medical Technology, Mae Sot General Hospital, Tak 63110 (Thailand); Phopueng, Ittipol [Department of Community and Social Medicine, Mae Sot General Hospital, Tak 63110 (Thailand)

    2015-01-15

    Very few studies have shown renal and blood pressure effects from environmental cadmium exposure in children. This population study examined associations between urinary cadmium excretion, a good biomarker of long-term cadmium exposure, and renal dysfunctions and blood pressure in environmentally exposed Thai children. Renal functions including urinary excretion of β{sub 2}-microglobulin, calcium (early renal effects), and total protein (late renal effect), and blood pressure were measured in 594 primary school children. Of the children studied, 19.0% had urinary cadmium ≥1 μg/g creatinine. The prevalence of urinary cadmium ≥1 μg/g creatinine was significantly higher in girls and in those consuming rice grown in cadmium-contaminated areas. The geometric mean levels of urinary β{sub 2}-microglobulin, calcium, and total protein significantly increased with increasing tertiles of urinary cadmium. The analysis did not show increased blood pressure with increasing tertiles of urinary cadmium. After adjusting for age, sex, and blood lead levels, the analysis showed significant positive associations between urinary cadmium and urinary β{sub 2}-microglobulin and urinary calcium, but not urinary total protein nor blood pressure. Our findings provide evidence that environmental cadmium exposure can affect renal functions in children. A follow-up study is essential to assess the clinical significance and progress of renal effects in these children. - Highlights: • Few studies show renal effects from environmental cadmium exposure in children. • We report renal and blood pressure effects from cadmium exposure in Thai children. • Urinary β{sub 2}-microglobulin and calcium increased with increasing urinary cadmium. • The study found no association between urinary cadmium levels and blood pressure. • Environmental cadmium exposure can affect renal functions in children.

  4. Nanoscale thermal probing

    Directory of Open Access Journals (Sweden)

    Yanan Yue

    2012-03-01

    Full Text Available Nanoscale novel devices have raised the demand for nanoscale thermal characterization that is critical for evaluating the device performance and durability. Achieving nanoscale spatial resolution and high accuracy in temperature measurement is very challenging due to the limitation of measurement pathways. In this review, we discuss four methodologies currently developed in nanoscale surface imaging and temperature measurement. To overcome the restriction of the conventional methods, the scanning thermal microscopy technique is widely used. From the perspective of measuring target, the optical feature size method can be applied by using either Raman or fluorescence thermometry. The near-field optical method that measures nanoscale temperature by focusing the optical field to a nano-sized region provides a non-contact and non-destructive way for nanoscale thermal probing. Although the resistance thermometry based on nano-sized thermal sensors is possible for nanoscale thermal probing, significant effort is still needed to reduce the size of the current sensors by using advanced fabrication techniques. At the same time, the development of nanoscale imaging techniques, such as fluorescence imaging, provides a great potential solution to resolve the nanoscale thermal probing problem.

  5. Einstein Inflationary Probe (EIP)

    Science.gov (United States)

    Hinshaw, Gary

    2004-01-01

    I will discuss plans to develop a concept for the Einstein Inflation Probe: a mission to detect gravity waves from inflation via the unique signature they impart to the cosmic microwave background (CMB) polarization. A sensitive CMB polarization satellite may be the only way to probe physics at the grand-unified theory (GUT) scale, exceeding by 12 orders of magnitude the energies studied at the Large Hadron Collider. A detection of gravity waves would represent a remarkable confirmation of the inflationary paradigm and set the energy scale at which inflation occurred when the universe was a fraction of a second old. Even a strong upper limit to the gravity wave amplitude would be significant, ruling out many common models of inflation, and pointing to inflation occurring at much lower energy, if at all. Measuring gravity waves via the CMB polarization will be challenging. We will undertake a comprehensive study to identify the critical scientific requirements for the mission and their derived instrumental performance requirements. At the core of the study will be an assessment of what is scientifically and experimentally optimal within the scope and purpose of the Einstein Inflation Probe.

  6. Cadmium effects and accumulation in cultures of Prorocentrum micans (dinophyta)

    Science.gov (United States)

    Kayser, H.; Sperling, K.-R.

    1980-03-01

    Effects and accumulation of cadmium were studied in unialgal 10-1 batch-culture experiments with the dinoflagellate Prorocentrum micans Ehrenberg. Tests were made using sterile filtered North Sea water enriched with nitrate and phosphate only in order to avoid disturbances by complex formation. Cadmium was added to the cultures in amounts of 100 to 0.13 µg l-1. In one series it was added at the start of the experiments and in a second one after a growth period of 1 week. Addition of only 1.2 µg Cd l-1 reduces multiplication rates and maximum cell densities of the algae. Not until 0.4 µg Cd-1 does growth correspond to that of the controls. Cadmium concentrations were measured, after filtration, in the culture medium and in the biomass by means of flameless AAS. The cadmium content in algae increased from 2.7 µg g-1 (dry weight) in controls to 500 µg g-1 (dry weight) in media containing 100 µg Cd l-1. Uptake occurred rapidly during the first few days of the experiments, slowed down somewhat during exponential growth stage, and increased during decay of the cultures. Cadmium content of culture media remained nearly constant (Series 1) or decreased only slowly during experimental time (Series 2). The highest concentration factor was measured in the controls. It decreased with increasing metal concentration in the medium and increased with experimental time. Structural modifications of the cells were visible after Lugol fixation only, indicating brittleness of the cell walls. P. micans has shown to be extremely sensitive to cadmium and to accumulate this metal.

  7. Cadmium toxicity to ringed seals (Phoca hispida): an epidemiological study of possible cadmium-induced nephropathy and osteodystrophy in ringed seals (Phoca hispida) from Qaanaaq in Northwest Greenland

    DEFF Research Database (Denmark)

    Sonne-Hansen, C; Dietz, R; Leifsson, P S;

    2002-01-01

    . Experience from cadmium-poisoned humans and laboratory mammals indicates that concentrations above 50-200 microg/g wet wt. may induce histopathological changes. Overall, 31 of the ringed seals had cadmium concentrations in the kidney cortex above 50 microg/g wet wt., 11 had concentrations above 100 and one......The Greenland marine food chains contain high levels of cadmium, mercury and selenium. Concentrations of cadmium in the kidney of ringed seals (Phoca hispida) from the municipalities of Qaanaaq and Upernavik (Northwest Greenland) are among the highest recorded in the Arctic. The purpose...... of the study was to determine whether cadmium-induced damage in the kidneys and the skeletal system could be detected among 100 ringed seals from Northwest Greenland. The cadmium concentrations in the kidney cortex ranged from 0 to 248 microg/g wet weight (mean=44.5, N=100) in the 99 kidneys examined...

  8. [Principle for strategic decision based on population health risk in emergence environmental cadmium pollution control].

    Science.gov (United States)

    Shang, Qi

    2012-05-01

    The principles for strategic decision in emergence environmental pollution control was summarized based on population health risk and features of emergence events of environmental cadmium pollution. Main task and strategies for the events control was suggested in emergency treatment and post-event for water and soil cadmium pollution respectively. The work, monitoring method, key problems for both environment cadmium pollution and human health risk, and main content of health education for cadmium exposure people was proposed in follow-up action, at meanwhile, achievements of study on human health effects caused by environmental cadmium pollution was introduced briefly over recent years.

  9. Zinc-Nickel Codeposition in Sulfate Solution Combined Effect of Cadmium and Boric Acid

    Directory of Open Access Journals (Sweden)

    Y. Addi

    2011-01-01

    Full Text Available The combined effect of cadmium and boric acid on the electrodeposition of zinc-nickel from a sulfate has been investigated. The presence of cadmium ion decreases zinc in the deposit. In solution, cadmium inhibits the zinc ion deposition and suppresses it when deposition potential value is more negative than −1.2 V. Low concentration of CdSO4 reduces the anomalous nature of Zn-Ni deposit. Boric acid decreases current density and shifts potential discharge of nickel and hydrogen to more negative potential. The combination of boric acid and cadmium increases the percentage of nickel in the deposit. Boric acid and cadmium.

  10. Contribution of an Auxin to the Uptake of Nickel and Cadmium in Maize Seedlings

    Institute of Scientific and Technical Information of China (English)

    GUO DONG-SHENG; XI YU-YING; WANG AI-YING; ZHANG JUN; YUAN XIAO-YING

    1999-01-01

    Maize seedlings were cultured in nickel or cadmium contaminated sand treated with α-naphthylacetic acid (NAA). The effects of NAA on nickel and cadmium uptake in roots, shoots, and subcellular fractions (cell wall, nuclei and remained parts of seedling cells) were determined. The data showed growth promotion when NAA was applied at low concentrations and inhibition at high concentrations. Uptake of nickel and cadmium content increased concurrently in roots and shoots. In the subcellular fraction, nickel and cadmium was greatest in the cell wall. The changes in growth had greatest correlation with nickel and cadmium content in the subcellular fraction.

  11. Purification and characterization of a cadmium-induced metallothionein from the shore crab Carcinus maenas (L.)

    DEFF Research Database (Denmark)

    Pedersen, K L; Pedersen, S N; Højrup, P;

    1994-01-01

    Two metallothionein variants were purified from the midgut gland of crabs (Carcinus maenas) exposed to a high cadmium concentration (2 p.p.m.). One of the variants was purified from crabs exposed to a low cadmium concentration (0.5 p.p.m.). The purification method involved acetone precipitation...... from crabs exposed to the high cadmium concentration differed only by a single residue of methionine at the N-terminus. The single variant isolated from crabs exposed to the low cadmium concentration was the one without the N-terminal methionine, indicating that high cadmium concentrations either...

  12. Nine New Fluorescent Probes

    Science.gov (United States)

    Lin, Tsung-I.; Jovanovic, Misa V.; Dowben, Robert M.

    1989-06-01

    Absorption and fluorescence spectroscopic studies are reported here for nine new fluorescent probes recently synthesized in our laboratories: four pyrene derivatives with substituents of (i) 1,3-diacetoxy-6,8-dichlorosulfonyl, (ii) 1,3-dihydroxy-6,8-disodiumsulfonate, (iii) 1,3-disodiumsulfonate, and (iv) l-ethoxy-3,6,8-trisodiumsulfonate groups, and five [7-julolidino] coumarin derivatives with substituents of (v) 3-carboxylate-4-methyl, (vi) 3- methylcarboxylate, (vii) 3-acetate-4-methyl, (viii) 3-propionate-4-methyl, and (ix) 3-sulfonate-4-methyl groups. Pyrene compounds i and ii and coumarin compounds v and vi exhibit interesting absorbance and fluorescence properties: their absorption maxima are red shifted compared to the parent compound to the blue-green region, and the band width broadens considerably. All four blue-absorbing dyes fluoresce intensely in the green region, and the two pyrene compounds emit at such long wavelengths without formation of excimers. The fluorescence properties of these compounds are quite environment-sensitive: considerable spectral shifts and fluorescence intensity changes have been observed in the pH range from 3 to 10 and in a wide variety of polar and hydrophobic solvents with vastly different dielectric constants. The high extinction and fluorescence quantum yield of these probes make them ideal fluorescent labeling reagents for proteins, antibodies, nucleic acids, and cellular organelles. The pH and hydrophobicity-dependent fluorescence changes can be utilized as optical pH and/or hydrophobicity indicators for mapping environmental difference in various cellular components in a single cell. Since all nine probes absorb in the UV, but emit at different wavelengths in the visible, these two groups of compounds offer an advantage of utilizing a single monochromatic light source (e.g., a nitrogen laser) to achieve multi-wavelength detection for flow cytometry application. As a first step to explore potential application in

  13. Synthesis and characterization of cadmium doped lead–borate glasses

    Indian Academy of Sciences (India)

    A A Alemi; H Sedghi; A R Mirmohseni; V Golsanamlu

    2006-02-01

    Cadmium doped lead–borate glasses were prepared from the melts in appropriate proportions of PbO2, H3BO3 and (15–40 mol%) CdO mixture in the temperature range 700–950°C. The infrared spectra of the glasses in the range 400–4000 cm-1 show their structures. No boroxol ring formation was observed in the structure of these glasses. Furthermore, doped cadmium atoms were not seen in tetrahedral coordination. But the conversion of three-fold to four-fold coordination of boron atoms in the structure of glasses was observed.

  14. Si Isotopes of Brownleeite

    Science.gov (United States)

    Nakamura-Messenger, K.; Messenger, Scott R.; Ito, M.; Keller, L. P.; Clemett, S. J.; Jones, J. H.; Tatsuoka, H.; Zolensky, M. E.; Tatsuoka, H.

    2010-01-01

    Brownleeite is a manganese silicide, ideally stoichiometric MnSi, not previously observed in nature until its discovery within an interplanetary dust particle (IDP) that likely originated from a comet [1]. Three discrete brownleeite grains in the IDP L2055 I3 (4 microns in size, hereafter IDP I3) were identified with maximum dimensions of 100, 250 and 600 nm and fully analyzed using scanning-transmission electron microscopy (STEM) [1]. One of the grains (100 nm in size) was poikilitically enclosed by low-Fe, Mn-enriched (LIME) olivine. LIME olivine is epitaxial to the brownleeite with the brownleeite (200) parallel to the olivine c* [1]. LIME olivine is an enigmatic phase first reported from chondritic porous IDPs and some unequilibrated ordinary chondrites [ 2], that is commonly observed in chondritic-porous IDPs. Recently, LIME olivine has been also found in comet Wild-2 (Stardust) samples [3], indicating that LIME olivine is a common mineral component of comets. LIME olivine has been proposed to form as a high temperature condensate in the protosolar nebula [2]. Brownleeite grains also likely formed as high-temperature condensates either in the early Solar System or in the outflow of an evolved star or supernova explosion [1]. The isotopic composition of the brownleeite grains may strongly constrain their ultimate source. To test this hypothesis, we performed isotopic analyses of the brownleeite and the associated LIME olivine, using the NASA/JSC NanoSIMS 50L ion microprobe.

  15. THE CD ISOTOPE SIGNATURE OF THE SOUTHERN OCEAN

    Science.gov (United States)

    Abouchami, W.; Galer, S. J.; Middag, R.; de Baar, H.; Andreae, M. O.; Feldmann, H.; Raczek, I.

    2009-12-01

    The availability of micronutrients can limit and control plankton ecosystems, notably in the Southern Ocean which plays a major role in regulating the CO2 biological pump. Cadmium has a nutrient-like distribution in seawater - it is directly incorporated into living plankton in the upper water column and re-mineralised at depth. The nutritional role of Cd (Price and Morel, 1990) makes it a potentially useful tracer of biological productivity. We report Cd concentration and Cd stable isotope data obtained using a double-spike TIMS method on seawater samples collected during the Zero and Drake Passage cruise (ANTXXIV-III, IPY-GEOTRACES 2008). Four vertical profiles were collected from 40 to 70°S across the Polar Front using the ultra-clean Titan frame (De Baar et al., 2008), providing a record of changes in biological productivity from the Subantarctic to the Antarctic region. Data from two profiles from the SE Atlantic (47.66°S, 4.28W) and Drake Passage (55.13°S, 65.53°W) obtained on 1 litre-sized samples are presented. Both profiles show a increase in Cd concentration with depth, with noticeably higher concentrations in the SE Atlantic. Cd and PO4 are positively correlated with distinct slopes for the two profiles. The Cd isotope data are expressed as ɛ112/110Cd relative to our JMC Mainz standard (± 8ppm, 2SD, N=17). ɛ112/110Cd values show a continuous decrease with increasing depth and a significant shift towards heavier values in the upper 400m at both stations resolvable outside analytical error (2SE ≤ 20ppm). The sense of Cd isotope fractionation confirms previous findings of uptake of “light” Cd by phytoplankton in the upper water column (Lacan et al., 2006; Ripperger et al., 2007; Schmidt et al., 2009). Most important is the evidence for a distinctive heavier Cd isotope signature in AASW relative to AAIW. This result demonstrates that different water masses carry distinct Cd isotopic compositions reflecting changes in Cd uptake by phytoplankton

  16. Direct mass measurements of Cd isotopes show strong shell gap at N=82

    CERN Document Server

    Knöbel, R; Bosch, F; Boutin, D; Chen, L; Dimopoulou, C; Dolinskii, A; Franczak, B; Franzke, B; Geissel, H; Hausmann, M; Kozhuharov, C; Kurcewicz, J; Litvinova, S A; Martínez-Pinedo, G; Matoš, M; Mazzocco, M; Münzenberg, G; Nakajima, S; Nociforo, C; Nolden, F; Ohtsubo, T; Ozawa, A; Patyk, Z; Plaß, W R; Scheidenberger, C; Stadlmann, J; Steck, M; Sun, B; Suzuki, T; Walker, P; Weick, H; Wu, M -R; Winkler, M; Yamaguchi, T

    2015-01-01

    A $^{238}$U projectile beam was used to create cadmium isotopes via abrasion-fission at 410 MeV/u in a beryllium target at the entrance of the in-flight separator FRS at GSI. The fission fragments were separated with the FRS and injected into the isochronous storage ring ESR for mass measurements. The Isochronous Mass Spectrometry (IMS) was performed under two different experimental conditions, with and without B$\\rho$-tagging at the dispersive central focal plane of the FRS. In the experiment with B$\\rho$-tagging the magnetic rigidity of the injected fragments was determined by an accuracy of $2\\times 10^{-4}$. A new method of data analysis, using a correlation matrix for the combined data set from both experiments, has provided mass values for 25 different isotopes for the first time. The high selectivity and sensitivity of the experiment and analysis has given access even to rare isotopes detected with a few atoms per week. In this letter we present for the $^{129,130,131}$Cd isotopes mass values directly ...

  17. Calcium isotopes in wine

    Science.gov (United States)

    Holmden, C. E.

    2011-12-01

    The δ 44/40Ca values of bottled wine vary between -0.76% to -1.55% on the seawater scale and correlate weakly with inverse Ca concentration and Mg/Ca ratio, such that the lowest δ 44/40Ca values have the highest Ca concentrations and lowest Mg/Ca ratios. The correlation is notable in the sense that the measured wines include both whites and reds sampled from different wine growing regions of the world, and cover a wide range of quality. Trends among the data yield clues regarding the cause of the observed isotopic fractionation. White wines, and wines generally perceived to be of lower quality, have lower δ 44/40Ca values compared to red wines and wines of generally perceived higher quality. Quality was assessed qualitatively through sensory evaluation, price, and scores assigned by critics. The relationship between δ 44/40Ca and wine quality was most apparent when comparing wines of one varietal from one producer from the same growing region. In the vineyard, wine quality is related to factors such as the tonnage of the crop and the ripeness of the grapes at the time of harvesting, the thickness of the skins for reds, the age of the vines, as well as the place where the grapes were grown (terroir). Quality is also influenced by winemaking practices such as fermentation temperature, duration of skin contact, and barrel ageing. Accordingly, the relationship between δ 44/40Ca and wine quality may originate during grape ripening in the vineyard or during winemaking in the cellar. We tested the grape ripening hypothesis using Merlot grapes sampled from a vineyard in the Okanagan, British Columbia, using sugar content (degrees Brix) as an indicator of ripeness. The grapes were separated into pulp, skin, and pip fractions and were analyzed separately. Thus far, there is no clear evidence for a systematic change in δ 44/40Ca values associated with progressive ripening of grapes in the vineyard. On the day of harvesting, the δ 44/40Ca value of juice squeezed from

  18. Shell structure of potassium isotopes deduced from their magnetic moments

    CERN Document Server

    Papuga, J; Kreim, K; Barbieri, C; Blaum, K; De Rydt, M; Duguet, T; Garcia Ruiz, R F; Heylen, H; Kowalska, M; Neugart, R; Neyens, G; Nortershauser, W; Rajabali, M M; Sanchez, R; Smirnova, N; Soma, V; Yordanov, D T

    2014-01-01

    $\\textbf{Background:}$ Ground-state spins and magnetic moments are sensitive to the nuclear wave function, thus they are powerful probes to study the nuclear structure of isotopes far from stability. \\\\ \\\\ $\\textbf{Purpose:}$ Extend our knowledge about the evolution of the $1/2^+$ and $3/2^+$ states for K isotopes beyond the $N = 28$ shell gap. \\\\ \\\\ $\\textbf{Method:}$ High-resolution collinear laser spectroscopy on bunched atomic beams. \\\\ \\\\ $\\textbf{Results:}$ From measured hyperfine structure spectra of K isotopes, nuclear spins and magnetic moments of the ground states were obtained for isotopes from $N = 19$ up to $N = 32$. In order to draw conclusions about the composition of the wave functions and the occupation of the levels, the experimental data were compared to shell-model calculations using SDPF-NR and SDPF-U effective interactions. In addition, a detailed discussion about the evolution of the gap between proton $1d_{3/2}$ and $2s_{1/2}$ in the shell model and $\\textit{ab initio}$ framework is al...

  19. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador

    Energy Technology Data Exchange (ETDEWEB)

    Chavez, E. [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas (Ecuador); He, Z.L., E-mail: zhe@ufl.edu [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Stoffella, P.J. [University of Florida, Institute of Food and Agricultural Science, Indian River Research and Education Center, Fort Pierce, FL 34945 (United States); Mylavarapu, R.S. [University of Florida, Institute of Food and Agricultural Science, Soil and Water Science Department, Gainesville, FL 33611 (United States); Li, Y.C. [University of Florida, Institute of Food and Agricultural Science, Tropical Research and Education Center, Homestead, FL 33031 (United States); Moyano, B. [Escuela Superior Politecnica del Litoral, Centro de Investigaciones Biotecnologicas del Ecuador, Guayaquil, Guayas (Ecuador); Baligar, V.C. [United State Department of Agriculture, ARS, Beltsville, MD 20705 (United States)

    2015-11-15

    Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg{sup −1}) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0–5, 5–15, 15–30, and 30–50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg{sup −1}, respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg{sup −1}. Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg{sup −1}), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans > shell > > leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg{sup −1}, and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0–5 and 5–15 cm depths (r = 0.80 and 0.82 for M3, and r = 0.78 and 0.82 for HCl; P < 0.01). These results indicate that accumulation of Cd in surface layers results in excessive Cd in cacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils. - Highlights: • > 60% of the studied sites had a Cd content in cacao beans above the critical level. • Bean Cd concentration was closely correlated with available Cd in soil. • Soil

  20. Concentration of cadmium in cacao beans and its relationship with soil cadmium in southern Ecuador.

    Science.gov (United States)

    Chavez, E; He, Z L; Stoffella, P J; Mylavarapu, R S; Li, Y C; Moyano, B; Baligar, V C

    2015-11-15

    Cadmium (Cd) content in cacao beans above a critical level (0.6 mg kg(-1)) has raised concerns in the consumption of cacao-based chocolate. Little is available regarding Cd concentration in soil and cacao in Ecuador. The aim of this study was to determine the status of Cd in both, soils and cacao plants, in southern Ecuador. Soil samples were collected from 19 farms at 0-5, 5-15, 15-30, and 30-50 cm depths, whereas plant samples were taken from four nearby trees. Total recoverable and extractable Cd were measured at the different soil depths. Total recoverable Cd ranged from 0.88 to 2.45 and 0.06 to 2.59, averaged 1.54 and 0.85 mg kg(-1), respectively in the surface and subsurface soils whereas the corresponding values for M3-extractable Cd were 0.08 to 1.27 and 0.02 to 0.33 with mean values of 0.40 and 0.10 mg kg(-1). Surface soil in all sampling sites had total recoverable Cd above the USEPA critical level for agricultural soils (0.43 mg kg(-1)), indicating that Cd pollution occurs. Since both total recoverable and M3-extractable Cd significantly decreased depth wise, anthropogenic activities are more likely the source of contamination. Cadmium in cacao tissues decreased in the order of beans>shell>leaves. Cadmium content in cacao beans ranged from 0.02 to 3.00, averaged 0.94 mg kg(-1), and 12 out of 19 sites had bean Cd content above the critical level. Bean Cd concentration was highly correlated with M3- or HCl-extractable Cd at both the 0-5 and 5-15 cm depths (r=0.80 and 0.82 for M3, and r=0.78 and 0.82 for HCl; Pcacao beans and M3- or HCl-extractable Cd are suitable methods for predicting available Cd in the studied soils.

  1. Potentiation of cadmium nephrotoxicity by acetaminophen

    Energy Technology Data Exchange (ETDEWEB)

    Bernard, A.M.; Russis, R. de; Ouled Amor, A.; Lauwerys, R.R.

    1988-10-01

    The possible interactions between acetaminophen and cadmium (Cd) on the kidney were investigated in female Sprague-Dawley rats. Acetaminophen was administered in the food at an average dose of 900 mg/kg and Cd in drinking water at the concentration of 200 ppm. The treatment with acetaminophen and Cd lasted 2 and 10 months, respectively. No interaction between Cd and acetaminophen was observed during the period of their concomitant administration: the increase in albuminuria caused by Cd and acetaminophen was additive, while the tubular impairment caused by acetaminophen (increased ..beta../sub 2/-microglobulinuria and decreased kidney concentrating ability) was not exacerbated by Cd. None of these treatments affected the glomerular filtration rate. Four months after the end of acetaminophen treatment, the renal changes had almost completely disappeared in the rats which had received the analgesic alone. Those continously exposed to Cd had developed slight tubular damage, as evidenced by an increased urinary excretion of ..beta../sub 2/-microglobulin and ..beta..-N-acetylglucosaminidase. By contrast, rats pretreated with acetaminophen for 2 months and exposed to Cd showed a marked increase in urinary excretion of albumin and ..beta../sub 2/-microglobulin, suggesting an interaction between both treatments. At the end of the study, only the interaction with ..beta../sub 2/-microglobulin excretion was still evident; that with the urinary excretion of ..beta..-N-acetylglucosaminidase and albumin having been masked by the chronic progessive nephrosis affecting most animals at that stage. As acetaminophen had no effect on the renal accumulation of Cd, it may be concluded that pretreatment with this analygesic at a dose causing slight tubular dysfunction renders rat kidney more sensitive to the nephrotoxic action of Cd. This observation may be of clinical relevance for population groups occupationally or environmentally exposed to Cd.

  2. High resolution isotope shifts and hyperfine structure measurements of tungsten by laser induced fluorescence spectroscopy

    CERN Document Server

    Lee, Jeongwon; Leanhardt, Aaron

    2012-01-01

    Isotope shifts and hyperfine structure of tungsten were studied in the near UV range. We have used laser induced fluorescence spectroscopy on a pulsed supersonic beam to probe the 5D0 -> 5F1 transition at 384.9 nm, 7S3 -> 7P4 transition at 400.9 nm, and 7S3 -> 7P3 transition at 407.4 nm. Three new magnetic hyperfine constants are reported for 7P3,7P4, and 5F1 states. The isotope shifts of the 384.9 nm transition are presented for the first time, and the isotope shifts of 400.9 nm and 407.4 nm transition are measured with an order of magnitude higher precision compared to the previous measurements. As a result, the nuclear parameters lambda and lambda_{rel} are extracted from the isotope shifts with an improved precision.

  3. Cadmium concentration in sea bottom sediment and its potential risk in the upper Gulf of Thailand.

    Science.gov (United States)

    Ei Tun, Zin Hnin; Parkpian, Preeda; Delaune, R D; Gambrell, R P; Jugsujinda, Aroon

    2009-02-15

    Untreated or partially treated waste water discharge from industrial and domestic sources entering the Upper Gulf of Thailand have been reported to increase cadmium concentration in bottom sediment. This study was directed at providing a better understanding of cadmium transformation in the sediment from the area. Sediment samples collected from Chao Phraya River mouth (CPY), Bang Pakong River mouth (BPK) and Klong Dan estuary (KD) located in the Upper Gulf of Thailand were analyzed for cadmium concentration in various sediment particle size fractions. Using laboratory microcosms, cadmium release from sediment as affected by salinity and sediment redox condition was studied. A higher concentration of cadmium (0.2-0.6 microg/g dry weight) was measured in finer sediment particle size fractions (<0.075 mm) as compared to courser fractions at all sampling stations. Cadmium release from the sediment to water was influenced by both salinity and redox condition. Sediment was spiked with 10 ppm cadmium which is the cadmium level in sediment adopted by the Australia and New Zealand sediment quality guidelines which can cause adverse environmental impacts. Experiments conducted showed soluble cadmium concentration at sediment oxidation reduction conditions representative of bottom sediment were at levels that can adversely impact aquatic organisms, according to the PCADMIUM water quality guideline. In Thailand, there is no sediment quality guideline. Based on these experiments, 10 ppm of cadmium in sediment was recommended as a regulatory guidelines for allowable levels of cadmium in sediment in the study area.

  4. Dietary intake and urinary level of cadmium and breast cancer risk: A meta-analysis.

    Science.gov (United States)

    Lin, Jinbo; Zhang, Fang; Lei, Yixiong

    2016-06-01

    Cadmium, a human carcinogenic heavy metal, has been reported to be associated with breast cancer risk; however, the results from the epidemiological studies are not always consistent. The objective of this study was to quantitatively summarize the current evidence for the relationship between cadmium exposure and breast cancer risk using meta-analysis methods. Six studies determining the dietary cadmium intake level and five studies evaluating the urinary cadmium level were identified in a systematic search of MEDLINE and PubMed databases, and the associations between these levels and breast cancer risk were analysed. The pooled estimates under the random-effects model suggested that higher urinary cadmium levels were associated with an increased risk for breast cancer (highest versus lowest quantile, pooled odds ratio [OR]=2.24, 95% confidence interval [95%CI]=1.49-3.35) and a 1μg/g creatinine increase in urinary cadmium led to a 1.02-fold increment of breast cancer (pooled OR=2.02, 95%CI=1.34-3.03); however, pooled estimates for dietary cadmium intake found no significant association between cadmium exposure and breast cancer risk (highest versus lowest quantile, pooled relative risk [RR]=1.01, 95%CI=0.89-1.15). These results suggest that cadmium exposure may lead to an increased risk of breast cancer, and urinary cadmium levels can serve as a reliable biomarker for long-term cadmium exposure and may predict the breast cancer risk.

  5. [Physiological response and bioaccumulation of Panax notoginseng to cadmium under hydroponic].

    Science.gov (United States)

    Li, Zi-wei; Yang, Ye; Cui, Xiu-ming; Liao, Pei-ran; Ge, Jin; Wang, Cheng-xiao; Yang, Xiao-yan; Liu, Da-hui

    2015-08-01

    The physiological response and bioaccumulation of 2-year-old Panax notoginseng to cadmium stress was investigated under a hydroponic experiment with different cadmium concentrations (0, 2.5, 5, 10 μmol · L(-1)). Result showed that low concentration (2.5 μmol · L(-1)) of cadmium could stimulate the activities of SOD, POD, APX in P. notoginseng, while high concentration (10 μmol · L(-1)) treatment made activities of antioxidant enzyme descended obviously. But, no matter how high the concentration of cadmium was, the activities of CAT were inhibited. The Pn, Tr, Gs in P. notoginseng decreased gradually with the increase of cadmium concentration, however Ci showed a trend from rise to decline. The enrichment coefficients of different parts in P. notoginseng ranked in the order of hair root > root > rhizome > leaf > stem, and all enrichment coefficients decreased with the increase of concentration of cadmium treatments; while the cadmium content in different parts of P. notoginseng and the transport coefficients rose. To sum up, cadmium could affect antioxidant enzyme system and photosynthetic system of P. notoginseng; P. notoginseng had the ability of cadmium enrichment, so we should plant it in suitable place reduce for reducing the absorption of cadmium; and choose medicinal parts properly to lessen cadmium intake.

  6. Development of Mackintosh Probe Extractor

    Science.gov (United States)

    Rahman, Noor Khazanah A.; Kaamin, Masiri; Suwandi, Amir Khan; Sahat, Suhaila; Jahaya Kesot, Mohd

    2016-11-01

    Dynamic probing is a continuous soil investigation technique, which is one of the simplest soil penetration test. It basically consist of repeatedly driving a metal tipped probe into the ground using a drop weight of fixed mass and travel. Testing was carried out continuously from ground level to the final penetration depth. Once the soil investigation work done, it is difficult to pull out the probe rod from the ground, due to strong soil structure grip against probe cone and prevent the probe rod out from the ground. Thus, in this case, a tool named Extracting Probe was created to assist in the process of retracting the probe rod from the ground. In addition, Extracting Probe also can reduce the time to extract the probe rod from the ground compare with the conventional method. At the same time, it also can reduce manpower cost because only one worker involve to handle this tool compare with conventional method used two or more workers. From experiment that have been done we found that the time difference between conventional tools and extracting probe is significant, average time difference is 155 minutes. In addition the extracting probe can reduce manpower usage, and also labour cost for operating the tool. With all these advantages makes this tool has the potential to be marketed.

  7. A new and highly selective turn-on fluorescent sensor with fast response time for the monitoring of cadmium ions in cosmetic, and health product samples

    Science.gov (United States)

    Khani, Rouhollah; Ghiamati, Ebrahim; Boroujerdi, Ramin; Rezaeifard, Abdolreza; Zaryabi, Mohadeseh Hosseinpour

    2016-06-01

    Cadmium (Cd) which is an extremely toxic could be found in many products like plastics, fossil fuel combustion, cosmetics, water resources, and wastewaters. It is capable of causing serious environmental and health problems such as lung, prostate, renal cancers and the other disorders. So, the development of a sensor to continually monitor cadmium is considerably demanding. Tetrakis(4-nitrophenyl)porphyrin, T(4-NO2-P)P, was synthesized and used as a new and highly selective fluorescent probe for monitoring cadmium ions in the "turn-on" mode. There was a linear relationship between fluorescence intensity and the concentration of Cd(II) in the range of 1.0 × 10- 6 to 1.0 × 10- 5 mol L- 1 with a detection limit of 0.276 μM. To examine the most important parameters involved and their interactions in the sensor optimization procedure, a four-factor central composite design (CCD) combined with response surface modeling (RSM) was implemented. The practical applicability of the developed sensor was investigated using real cosmetic, and personal care samples.

  8. Probe-based data storage

    CERN Document Server

    Koelmans, Wabe W; Abelmann, L

    2015-01-01

    Probe-based data storage attracted many researchers from academia and industry, resulting in unprecendeted high data-density demonstrations. This topical review gives a comprehensive overview of the main contributions that led to the major accomplishments in probe-based data storage. The most investigated technologies are reviewed: topographic, phase-change, magnetic, ferroelectric and atomic and molecular storage. Also, the positioning of probes and recording media, the cantilever arrays and parallel readout of the arrays of cantilevers are discussed. This overview serves two purposes. First, it provides an overview for new researchers entering the field of probe storage, as probe storage seems to be the only way to achieve data storage at atomic densities. Secondly, there is an enormous wealth of invaluable findings that can also be applied to many other fields of nanoscale research such as probe-based nanolithography, 3D nanopatterning, solid-state memory technologies and ultrafast probe microscopy.

  9. Ecological toxicity of reactive X-3B red dye and cadmium acting on wheat (Triticum aestivum)

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Ecological toxicity of reactive X-3B red dye and cadmium in both their single form and their combined form on wheat was studied using the experimental method of seed and root exposure. The single-factor exposure indicated that the inhibitory rate of wheat root elongation was significantly increased with the increase in the concentration of the dye in the cultural solution, although seed germination of wheat was not sensitive to the dye. The toxicity of cadmium was greatly higher than that of the dye, but low concentration cadmium (< 40 mg/L) could promote the germination of wheat seed. Interactive effects of the dye and cadmium on wheat were complicated. There was no significant correlation between the inhibitory rate of seed germination and the concentrations of the dye and cadmium. Low concentration cadmium could strengthen the toxicity of the dye acting on root elongation. On the contrary, high concentration cadmium could weaken the toxicity of the dye acting on root elongation.

  10. Cadmium causes delayed effects on renal function in the offspring of cadmium-contaminated pregnant female rats.

    Science.gov (United States)

    Jacquillet, G; Barbier, O; Rubera, I; Tauc, M; Borderie, A; Namorado, M C; Martin, D; Sierra, G; Reyes, J L; Poujeol, P; Cougnon, M

    2007-11-01

    In the adult rat, chronic cadmium intoxication induces nephropathy with Fanconi-like features. This result raises the question of whether intoxication of pregnant rats has any deleterious effects on renal function in their offspring. To test this hypothesis, we measured the renal function of 2- to 60-day-old postnatal offspring from female rats administered cadmium chloride by the oral route (0.5 mg.kg(-1).day(-1)) throughout their entire gestation. Investigations of rat offspring from contaminated pregnant rats showed the presence of cadmium in the kidney at gestational day 20. After birth, the cadmium kidney concentration increased from postnatal day 2 to day 60 (PND2 to PND60), presumably because of 1) milk contamination and 2) neonatal liver cadmium content release. Although the renal parameters (glomerular filtration, U/P inulin, and urinary excretion rate) were not significantly affected until PND45, renal failure appeared at PND60, as demonstrated by a dramatic decrease of the glomerular filtration rate associated with increased excretion of the main ions. In parallel, an immunofluorescence study of tight-junction protein expression of PND60 offspring from contaminated rats showed a disorganization of the tight-junction proteins claudin-2 and claudin-5, specifically expressed in the proximal tubule and glomerulus, respectively. In contrast, expression of a distal claudin protein, claudin-3, was not affected. In conclusion, in utero exposure of cadmium leads to toxic renal effects in adult offspring. These results suggest that contamination of pregnant rats is a serious and critical hazard for renal function of their offspring.

  11. Dietary Cadmium Intake and Risk of Breast, Endometrial and Ovarian Cancer in Danish Postmenopausal Women: A Prospective Cohort Study

    OpenAIRE

    2014-01-01

    Purpose Cadmium is a human lung carcinogen and possesses estrogen-like activity. This combination of carcinogenic and estrogenic activity makes cadmium a contaminant of high concern for hormone-related cancers. Diet and smoking are the main sources of cadmium exposure. The aim of this study was to investigate the association between dietary cadmium intake and risk of breast, endometrial and ovarian cancer in Danish postmenopausal woman. Methods We estimated dietary cadmium intake in the Diet,...

  12. Undocumented water column sink for cadmium in open ocean oxygen-deficient zones

    Science.gov (United States)

    Janssen, David J.; Conway, Tim M.; John, Seth G.; Christian, James R.; Kramer, Dennis I.; Pedersen, Tom F.; Cullen, Jay T.

    2014-01-01

    Cadmium (Cd) is a micronutrient and a tracer of biological productivity and circulation in the ocean. The correlation between dissolved Cd and the major algal nutrients in seawater has led to the use of Cd preserved in microfossils to constrain past ocean nutrient distributions. However, linking Cd to marine biological processes requires constraints on marine sources and sinks of Cd. Here, we show a decoupling between Cd and major nutrients within oxygen-deficient zones (ODZs) in both the Northeast Pacific and North Atlantic Oceans, which we attribute to Cd sulfide (CdS) precipitation in euxinic microenvironments around sinking biological particles. We find that dissolved Cd correlates well with dissolved phosphate in oxygenated waters, but is depleted compared with phosphate in ODZs. Additionally, suspended particles from the North Atlantic show high Cd content and light Cd stable isotope ratios within the ODZ, indicative of CdS precipitation. Globally, we calculate that CdS precipitation in ODZs is an important, and to our knowledge a previously undocumented marine sink of Cd. Our results suggest that water column oxygen depletion has a substantial impact on Cd biogeochemical cycling, impacting the global relationship between Cd and major nutrients and suggesting that Cd may be a previously unidentified tracer for water column oxygen deficiency on geological timescales. Similar depletions of copper and zinc in the Northeast Pacific indicate that sulfide precipitation in ODZs may also have an influence on the global distribution of other trace metals. PMID:24778239

  13. Changes in Tissue Metals After Cadmium Intoxication and Intervention With Chlorpromazine in Male Rats 

    Institute of Scientific and Technical Information of China (English)

    YANGXIAO-FANG; WANGSHU-YI; 等

    2000-01-01

    Cadmium(Cd),one of the most dangerous heavy metals,has a very similar ionic radius to calcium(Ca),The interference of cadmium in calcium homeostasis may play an important role in cadmium toxicity.Recent reports indicate that calmodulin(CaM) inhibitors such as trifluoperazine and chlorpromazine(CPZ) could protect rodents against cadmium toxicity,It was also reported that pretreatment of mice with zine(Zn)could reduce the adverse effects induced by cadmium.The aim of this study is to determine whether Cd changes the balance of other essential metals such as Zn and copper(Cu) in rat tissues,and whether CPZ can reverse these changes which are induced by cadmium intoxication.Adult male Sprague-Dawley(SD) rats were injected intraperitoneally(ip) with cadmium chloride(CdCl2)(0.2,0.4,0.8mg Cd/kg body wight) alone and 0.4mg Cd/kg in association with CPZ(5mg/kg) daily for a week.The control animals were injected with normal saline only.The results showed that the cadmium content in the liver,kidney,and testis increased significantly with a dose-response relationship.Cadmium treatment markedly increased the Zn and Ca content in some of the tissues,Hepatic and renal metallothionein(MT) increased significantly after cadmium intoxication,CPZ treatment,howerver,reduced cadmium content in liver,but not blood and kidney.CPZ seemed to decrease the content of MT in liver and significantly increase the amounts of MT in kidney.These data suggest that the intervention of cadmium with tissue essential metals may play a role in cadium toxicity in rats,and calmodulin inhibitors to some extent can reduce the adverse effect of cadmium by decreasing the cadmium load in tissues and reversing the unbalance of essetial metals.

  14. Cadmium and zinc accumulation in soybean: A threat to food safety?

    Energy Technology Data Exchange (ETDEWEB)

    Shute, Tracy [Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada); Macfie, Sheila M. [Department of Biology, University of Western Ontario, London, ON N6A 5B7 (Canada)]. E-mail: smacfie@uwo.ca

    2006-12-01

    A greenhouse study was conducted to quantify cadmium and zinc accumulated by soybean (Glycine max (L.) Merr.) when the metals were supplied separately and together. The highest dose of cadmium (100 mg/kg) reduced plant height and dry weight (down to 40% and 34% of control, respectively); the highest dose of zinc (2000 mg/kg) reduced plant height to 55% of control and dry weight to 70% of control. With both metals present, the plants were approximately the same size as those treated with cadmium only. The concentration of cadmium in the roots was unaffected by zinc. In other tissues, the effect of zinc on the accumulation of cadmium depended on the doses provided. At low doses, the addition of zinc reduced the concentration of cadmium in aboveground tissues to 40-50% of that found in plants exposed to cadmium only. However, when applied in high doses, the presence of zinc in cadmium-contaminated soils increased the uptake and accumulation of cadmium in aboveground tissues by up to 42%. In contrast, at high doses, the presence of cadmium in zinc-contaminated soil resulted in approximately 35% lower concentrations of zinc in all tissues. At a lower dose, cadmium had no effect on concentration of zinc in the plant tissues. The effects of high doses of one metal on the uptake of the other metal can be partially explained by the effects of one metal on the bioavailability of the other metal. In soils to which only one metal was added, bioavailable cadmium was 70-80% of the total cadmium, and bioavailable zinc was 50-70% of the total zinc. When both metals were added to the soil, 80-100% of the cadmium and 46-60% of the zinc were bioavailable. Concentrations of both metals were highest in root tissues (10-fold higher for cadmium, and up to 2-fold higher for zinc). Although relatively little cadmium was translocated to pods and seeds, the seeds of all plants (including those from control and zinc-treated plants) had concentrations of cadmium 3-4 times above the limit of 0

  15. PROcess Based Diagnostics PROBE

    Science.gov (United States)

    Clune, T.; Schmidt, G.; Kuo, K.; Bauer, M.; Oloso, H.

    2013-01-01

    Many of the aspects of the climate system that are of the greatest interest (e.g., the sensitivity of the system to external forcings) are emergent properties that arise via the complex interplay between disparate processes. This is also true for climate models most diagnostics are not a function of an isolated portion of source code, but rather are affected by multiple components and procedures. Thus any model-observation mismatch is hard to attribute to any specific piece of code or imperfection in a specific model assumption. An alternative approach is to identify diagnostics that are more closely tied to specific processes -- implying that if a mismatch is found, it should be much easier to identify and address specific algorithmic choices that will improve the simulation. However, this approach requires looking at model output and observational data in a more sophisticated way than the more traditional production of monthly or annual mean quantities. The data must instead be filtered in time and space for examples of the specific process being targeted.We are developing a data analysis environment called PROcess-Based Explorer (PROBE) that seeks to enable efficient and systematic computation of process-based diagnostics on very large sets of data. In this environment, investigators can define arbitrarily complex filters and then seamlessly perform computations in parallel on the filtered output from their model. The same analysis can be performed on additional related data sets (e.g., reanalyses) thereby enabling routine comparisons between model and observational data. PROBE also incorporates workflow technology to automatically update computed diagnostics for subsequent executions of a model. In this presentation, we will discuss the design and current status of PROBE as well as share results from some preliminary use cases.

  16. Future trends in soil cadmium concentration under current cadmium fluxes to European agricultural soils.

    Science.gov (United States)

    Six, L; Smolders, E

    2014-07-01

    The gradual increase of soil cadmium concentrations in European soils during the 20th century has prompted environmental legislation to limit soil cadmium (Cd) accumulation. Mass balances (input-output) reflecting the period 1980-1995 predicted larger Cd inputs via phosphate (P) fertilizers and atmospheric deposition than outputs via crop uptake and leaching. This study updates the Cd mass balance for the agricultural top soils of EU-27+Norway (EU-27+1). Over the past 15 years, the use of P fertilizers in the EU-27+1 has decreased by 40%. The current mean atmospheric deposition of Cd in EU is 0.35 g Cd ha(-1) yr(-1), this is strikingly smaller than values used in the previous EU mass balances (~3 g Cd ha(-1) yr(-1)). Leaching of Cd was estimated with most recent data of soil solution Cd concentrations in 151 soils, which cover the range of European soil properties. No significant time trends were found in the data of net applications of Cd via manure, compost, sludge and lime, all being small sources of Cd at a large scale. Modelling of the future long-term changes in soil Cd concentrations in agricultural top soils under cereal or potato culture predicts soil Cd concentrations to decrease by 15% over the next 100 years in an average scenario, with decreasing trends in some scenarios being more prevalent than increasing trends in other scenarios. These Cd balances have reverted from the general positive balances estimated 10 or more years ago. Uncertainty analysis suggests that leaching is the most uncertain relative to other fluxes.

  17. Atom Probe Tomography 2012

    Science.gov (United States)

    Kelly, Thomas F.; Larson, David J.

    2012-08-01

    In the world of tomographic imaging, atom probe tomography (APT) occupies the high-spatial-resolution end of the spectrum. It is highly complementary to electron tomography and is applicable to a wide range of materials. The current state of APT is reviewed. Emphasis is placed on applications and data analysis as they apply to many fields of research and development including metals, semiconductors, ceramics, and organic materials. We also provide a brief review of the history and the instrumentation associated with APT and an assessment of the existing challenges in the field.

  18. Atom probe tomography today

    Directory of Open Access Journals (Sweden)

    Alfred Cerezo

    2007-12-01

    Full Text Available This review aims to describe and illustrate the advances in the application of atom probe tomography that have been made possible by recent developments, particularly in specimen preparation techniques (using dual-beam focused-ion beam instruments but also of the more routine use of laser pulsing. The combination of these two developments now permits atomic-scale investigation of site-specific regions within engineering alloys (e.g. at grain boundaries and in the vicinity of cracks and also the atomic-level characterization of interfaces in multilayers, oxide films, and semiconductor materials and devices.

  19. Experimental probes of axions

    Energy Technology Data Exchange (ETDEWEB)

    Chou, Aaron S.; /Fermilab

    2009-10-01

    Experimental searches for axions or axion-like particles rely on semiclassical phenomena resulting from the postulated coupling of the axion to two photons. Sensitive probes of the extremely small coupling constant can be made by exploiting familiar, coherent electromagnetic laboratory techniques, including resonant enhancement of transitions using microwave and optical cavities, Bragg scattering, and coherent photon-axion oscillations. The axion beam may either be astrophysical in origin as in the case of dark matter axion searches and solar axion searches, or created in the laboratory from laser interactions with magnetic fields. This note is meant to be a sampling of recent experimental results.

  20. Mobile Probing Kit

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Sørensen, Lene Tolstrup; Sørensen, J.K.

    2007-01-01

    characterized as being highly nomadic and thus potential users of mobile and ubiquitous technologies. The methodology has been applied in the 1ST MAGNET Beyond project in order to obtain user needs and requirements in the process of developing pilot services. We report on the initial findings from applying......Mobile Probing Kit is a low tech and low cost methodology for obtaining inspiration and insights into user needs, requirements and ideas in the early phases of a system's development process. The methodology is developed to identify user needs, requirements and ideas among knowledge workers...

  1. Carbon isotope discrimination as a tool to explore C4 photosynthesis.

    Science.gov (United States)

    von Caemmerer, Susanne; Ghannoum, Oula; Pengelly, Jasper J L; Cousins, Asaph B

    2014-07-01

    Photosynthetic carbon isotope discrimination is a non-destructive tool for investigating C4 metabolism. Tuneable diode laser absorption spectroscopy provides new opportunities for making rapid, concurrent measurements of carbon isotope discrimination and CO2 assimilation over a range of environmental conditions, and this has facilitated the use of carbon isotope discrimination as a probe of C4 metabolism. In spite of the significant progress made in recent years, understanding how photosynthetic carbon isotope discrimination measured concurrently with gas exchange relates to carbon isotope composition of leaf and plant dry matter remains a challenge that requires resolution if this technique is to be successfully applied as a screening tool in crop breeding and phylogenetic research. In this review, we update our understanding of the factors and assumptions that underlie variations in photosynthetic carbon isotope discrimination in C4 leaves. Closing the main gaps in our understanding of carbon isotope discrimination during C4 photosynthesis may help advance research aimed at developing higher productivity and efficiency in key C4 food, feed, and biofuel crops.

  2. Competition from Isotopic Modelling

    Directory of Open Access Journals (Sweden)

    Virginie Fabre

    2011-01-01

    Full Text Available During later MOIS3, in Europe two populations were present, autochthonous Neanderthals and modern humans. Ecological competition between these two populations has often been evoked but never demonstrated. Our aim is to establish whether resource competition occurred. In this paper, in order to examine the possibility of ecological competition between these two populations, 599 isotopic data were subjected to rigorous statistical treatment and analysis through mixing models. The aim of this paper was to compare dietary strategies of Neanderthals and modern humans over time. Our conclusions suggest that Neanderthals and modern humans shared dietary habits in the particular environmental context of MOIS3 characterised in Europe by climatic deterioration. In this environmental context, the resource competition between Neanderthals and modern humans may have accelerated the disappearance of the Neanderthal population.

  3. Study of photoemission and work function of large surface areas, phase 3, phase 4. [wavelength dependences of photoelectric space probe materials

    Science.gov (United States)

    1973-01-01

    The photoemission of materials which might be used in probe measurements of the exo-atmospheric electric field is considered by evaluating the wavelength dependence of their photoelectric yield for eleven elements over the range 800 to 3200 A. Yield data for zinc, copper beryllium, platinum, cadmium, graphite, carbon, gold, silver, tantalum, and tungsten show that copper-beryllium is a preferred material. Silver has one of the highest photoemissions when exposed to solar radiation.

  4. Effects of cadmium on the health of the population

    Energy Technology Data Exchange (ETDEWEB)

    Piscator, M.

    1973-11-01

    Investigations on workers who have been exposed to cadmium dust or fumes in the breathing air have shown that lung damage, special emphysema and damage to the renal tubuli are the most frequently occurring symptoms for exposed industrial workers. The main characteristic of kidney damage is tubular proteinuria. An increased excretion of amino acids, glucose, calcium and phosphorus is likewise possible. Finally, disorders in the calcium and phosphorus metabolism can have demineralization of the bones for a consequence. According to estimates, the critical concentration in the cortex of the kidneys is ca 200 ..mu..g Cd/g wet weight. At this concentration, functional disorders of the kidneys can appear for the most sensitive individuals of a particular population. This estimate is based on results of investigations on humans and animals, although these were conducted with relatively imprecise methods; accordingly, the value may even lie below 200 ppm. From the toxicological viewpoint there is not too great a safety margin between the present cadmium level in adults and the critical value. It can be expected that this margin will become smaller in the future when additional cadmium loading of the environment occurs, since the retention of cadmium is practically equal to the uptake on account of the small excretion rate.

  5. Cadmium and zinc relationships in kidney cortex, liver, and pancreas

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Piscator, M.; Linnman, L.

    1977-06-01

    Zinc and cadmium have been determined in kidney cortex, liver, and pancreas from 292 subjects autopsied in Stockholm, Sweden. In the liver and pancreas zinc was found to have a normal frequency distribution, average 45.3 ..mu..g/g and 26.9 ..mu..g/g wet wt, respectively. The concentrations of zinc in these two organs were constant regardless of age at death. Zinc was shown to accumulate with age in the kidney cortex in a way similar to cadmium, and had a log-normal distribution. The calculation of the regression line between individual cadmium concentrations below 60 ..mu..g/g and zinc concentrations gave a slope constant of 0.61 (Y/sub Zn/ = 0.61 X/sub Cd/ + 24.4), which corresponds to a nearly equimolar increase of zinc. The concentrations of ''physiological zinc,'' i.e., total zinc minus the zinc related to cadmium, were normally distributed (anti x = 24.6 ..mu..g Zn/g) and did not change with age. Furthermore, data on dry weight/wet weight ratios and ash weight/dry weight ratios in relation to age are presented.

  6. Plant science: the key to preventing slow cadmium poisoning

    NARCIS (Netherlands)

    Clemens, S.; Aarts, M.G.M.; Thomine, S.; Verbruggen, N.

    2013-01-01

    Practically all human populations are environmentally exposed to cadmium (Cd), mostly through plant-derived food. A growing body of epidemiological evidence suggests that there is no margin of safety between current Cd exposure levels and the threshold for adverse health effects and, hence, there is

  7. On the existence of ‘L-alanine cadmium bromide'

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R.

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  8. On the existence of 'L-alanine cadmium bromide'.

    Science.gov (United States)

    Srinivasan, Bikshandarkoil R

    2013-12-01

    It is argued that the recently reported nonlinear optical crystal L-alanine cadmium bromide, grown by slow solvent evaporation method at room temperature [P. Ilayabarathi, J. Chandrasekaran, Spectrochim. Acta 96A (2012) 684-689] is the well-known L-alanine crystal. The isolation of L-alanine crystal is explained due to fractional crystallization.

  9. Uitwisselingsonderzoek voor de bepaling van cadmium in schuimaarde

    NARCIS (Netherlands)

    Veen, van der N.G.; Berghmans-van Megen, E.H.J.; Betteray-Kortekaas, van A.M.G.; Hovens, J.P.C.; Werdmuller, G.A.

    1982-01-01

    In het kader van een uitwisselingsonderzoek tussen het RIKILT en het IRS nagaan of verschillende methoden van onderzoek voor de bepaling van cadmium in schuimaarde vergelijkbare resultaten opleveren. In een uitwisselingsonderzoek tussen het RIKILT en het IRS (Instituut voor Rationele Suikerproduktie

  10. Lead and cadmium in wild birds in southeastern Spain

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Fernandez, A.J.; Sanchez-Garcia, J.A.; Luna, A. [Univ. of Murcia (Spain); Jimenez-Montalban, P. [Regional Environmental Agency, Murcia (Spain). Centro de Recuperacion de Fauna Silvestre El Valle

    1995-12-01

    The main purpose of this study was to monitor exposure to lead and cadmium in wild birds in Murcia, a southeastern region of Spain on the Mediterranean coast. This region lies on one of the African-European flyways. Samples of liver, kidney, brain, bone, and whole blood from several species of wild birds were obtained during 1993. The authors found a clear relationship between cadmium and lead concentrations in birds and their feedings habits. Vultures (Gyps fulvus) had the highest concentrations of lead (mean 40 {micro}g/dl in blood), and seagulls (Larus argentatus and Larus ridibundus) the highest concentrations of cadmium (mean 4.43 {micro}g/g in kidney). Insectivores had high concentrations of both metals, and diurnal and nocturnal raptors showed the lowest tissue concentrations. The findings that tissue and blood concentrations were generally not elevated suggests environmental (rather than acute) exposure. Birds from more industrialized areas of the region studied here had higher concentrations of both lead and cadmium.

  11. A method for partitioning cadmium bioaccumulated in small aquatic organisms

    Energy Technology Data Exchange (ETDEWEB)

    Siriwardena, S.N.; Rana, K.J.; Baird, D.J. [Univ. of Stirling (United Kingdom). Institute of Aquaculture

    1995-09-01

    A series of laboratory experiments was conducted to evaluate bioaccumulation and surface adsorption of aqueous cadmium (Cd) by sac-fry of the African tilapia Oreochromis niloticus. In the first experiment, the design consisted of two cadmium treatments: 15 {micro}g Cd{center_dot}L{sup {minus}1} in dilution water and a Cd-ethylenediaminetetraacetic acid (Cd-EDTA) complex at 15 {micro}m{center_dot}L{sup {minus}1}, and a water-only control. There were five replicates per treatment and 40 fish per replicate. It was found that EDTA significantly reduced the bioaccumulation of cadmium by tilapia sac-fry by 34%. Based on the results, a second experiment was conducted to evaluate four procedures: a no-rinse control; rinsing in EDTA; rinsing in distilled water; and rinsing in 5% nitric acid, for removing surface-bound Cd from exposed sac-fry. In this experiment, 30 fish in each of five replicates were exposed to 15 {micro}g Cd{center_dot}L{sup {minus}1} for 72 h, processed through the rinse procedures, and analyzed for total Cd. The EDTA rinse treatment significantly reduced (p<0.05) Cd concentrations of the exposed fish relative to those receiving no rinse. It was concluded that the EDTA rinse technique may be useful in studies evaluating the partitioning of surface-bound and accumulated cadmium in small aquatic organisms.

  12. Nickel cadmium batteries. Citations from the NTIS data base

    Science.gov (United States)

    Cavagnaro, D. M.

    1980-07-01

    The design, fabrication, components, testing, and assembly of nickel cadmium batteries are covered in the bibliography. The majority of these citations deal with the development of power supplies for aircraft and spacecraft. This updated bibliography contains 135 abstracts, 19 of which are new entries to the previous edition.

  13. Thermoelectric material comprising scandium doped zinc cadmium oxide

    DEFF Research Database (Denmark)

    2016-01-01

    There is presented a composition of scandium doped Zinc Cadmium Oxide with the general formula ZnzCdxScyO which the inventors have prepared, and for which material the inventors have made the insight that it is particularly advantageous as an n-type oxide material, such as particularly advantageous...

  14. Cadmium plated steel caps seal anodized aluminum fittings

    Science.gov (United States)

    Padden, J.

    1971-01-01

    Cadmium prevents fracturing of hard anodic coating under torquing to system specification requirements, prevents galvanic coupling, and eliminates need for crush washers, which, though commonly used in industry, do not correct leakage problem experienced when anodized aluminum fittings and anodized aluminum cap assemblies are joined.

  15. Gender differences in cadmium and cotinine levels in prepubertal children

    DEFF Research Database (Denmark)

    Fucic, A; Plavec, D; Casteleyn, L;

    2015-01-01

    and exposure data are scarce. In the current study levels of cadmium (Cd), cotinine and creatinine in urine were analyzed in a subsample 216 children from 12 European countries within the DEMOCOPHES project. The children were divided into six age-sex groups: boys (6-8 years, 9-10 years and 11 years old......), and girls (6-7 years, 8-9 years, 10-11 years). The number of subjects per group was between 23 and 53. The cut off values were set at 0.1µg/L for Cd, and 0.8µg/L for cotinine defined according to the highest limit of quantification. The levels of Cd and cotinine were adjusted for creatinine level...... between levels of cadmium and creatinine in all children of both genders. This shows that even at such low levels the possible effect of cadmium on kidney function was present and measurable. An increase in Cd levels was evident with age. Cadmium levels were significantly different between 6-7 year old...

  16. in situ immobilization of Cadmium and zinc in contaminated soils

    NARCIS (Netherlands)

    Osté, L.A.

    2001-01-01

    Keywords: beringite, cadmium, DOC, DOM, earthworms, immobilization, leaching, lime, manganese oxides, metal binding, metal uptake, organic matter partitioning, pH, soil contamination, remediation, sorption, Swiss chard, zeolites, zinc.It is generally assumed that a decrease in metal c

  17. Tribological performance of organic cadmium compound as lubricant additive

    Institute of Scientific and Technical Information of China (English)

    HU Jian-qiang; XIE Feng; ZHU Huan-qin; ZHEN Fa-zheng; YAO Jun-bing

    2004-01-01

    The oil-soluble cadmium dipropyldithiophosphate additive was synthesized. A four-ball tester was used to evaluate the tribological performance of the additive in a mineral oil under different loads and lubricant grease synthesized compared with some commercial additives. The results show that it exhibits excellent antiwear and load-carrying capacities and is better than other additives. The surface analytical tools such as scanning electron microscope (SEM) with energy dispersive X-ray (EDX), X-ray photoelectron spectrometer (XPS) were used to investigate the topography, the compositions, and chemical states of some typical elements on the rubbing surface of worn scar.Smooth and light topography of worn scar further confirms that the additive shows good antiwear capacities. The results of EDX and XPS analyses indicate that tribochemical mixed protective films consisting of atomic cadmium, sulphides, sulphates and phosphates are formed on the rubbing surface, which contribute to improving the tribological properties of lubricant and grease. Particularly, the soft cadmium film formed plays an important role in improving antiwear properties of oils. Finally, antiwear mechanism of the additive and formation scheme of atomic cadmium was proposed.

  18. Isotope Effects in ESR Spectroscopy

    Directory of Open Access Journals (Sweden)

    Werner Herrmann

    2013-06-01

    Full Text Available In order to present the relationship between ESR spectroscopy and isotope effects three levels are considered: (i ESR spectroscopy is described on a general level up to the models for interpretation of the experimental spectra, which go beyond the usually used time and mass independent spin-Hamilton operator, (ii the main characteristics of the generalized isotope effects are worked out, and finally (iii the basic, mainly quantum mechanical effects are used to describe the coupling of electron spins with the degrees of freedom, which are accessible under the selected conditions, of the respective paramagnetic object under investigation. The ESR parameters and the respective models are formalized so far, that they include the time and mass depending influences and reflect the specific isotope effects. Relations will be established between the effects in ESR spectra to spin relaxation, to spin exchange, to the magnetic isotope effect, to the Jahn-Teller effects, as well as to the influence of zero-point vibrations. Examples will be presented which demonstrate the influence of isotopes as well as the kind of accessible information. It will be differentiated with respect to isotope effects in paramagnetic centres itself and in the respective matrices up to the technique of ESR imaging. It is shown that the use of isotope effects is indispensable in ESR spectroscopy.

  19. Cross section measurement of alpha particle induced nuclear reactions on natural cadmium up to 52 MeV

    CERN Document Server

    Ditrói, F; Haba, H; Komori, Y; Aikawa, M

    2016-01-01

    Cross sections of alpha particle induced nuclear reactions have been measured on thin natural cadmium targets foils in the energy range from 11 to 51.2 MeV. This work was a part of our systematic study on excitation functions of light ion induced nuclear reactions on different target materials. Regarding the cross sections, the alpha induced reactions are not deeply enough investigated. Some of the produced isotopes are of medical interest, others have application in research and industry. The radioisotope $^{117m}$Sn is a very important theranostic (therapeutic + diagnostic) radioisotope, so special care was taken to the results for that isotope. The well-established stacked foil technique followed by gamma-spectrometry with HPGe gamma spectrometers were used. The target and monitor foils in the stack were commercial high purity metal foils. From the irradiated targets $^{117m}$Sn, $^{113}$Sn, $^{110}$Sn, $^{117m,g}$In, $^{116m}$In, $^{115m}$In, $^{114m}$In, $^{113m}$In, $^{111}$In, $^{110m,g}$In, $^{109m}$I...

  20. Lead, mercury, and cadmium in breast milk

    Directory of Open Access Journals (Sweden)

    Kadriye Yurdakök

    2015-10-01

    Full Text Available Toxic heavy metals are the major source of environmental pollution in this new millennium. Lead, mercury, and cadmium are the most common toxic heavy metals in the environment. There is no known function of these toxic heavy metals in the human body. In females, toxic heavy metals can be accumulated in maternal body before pregnancy and may be transferred to fetus through placenta and later, via breast milk. Lead previously accumulated in maternal bones can be mobilized along with calcium in order to meet increased calcium needs of the fetus in pregnant women and for the calcium needs in human milk during lactation. Human fetus and infants are susceptible to heavy metal toxicity passing through placenta and breastmilk due to rapid growth and development of organs and tissues, especially central nervous system. However most of the damage is already done by the time the infant is born. Intrauterine lead exposure can cause growth retardation, cognitive dysfunction, low IQ scores on ability tests, and low performance in school. Biological samples, such as umbilical cord blood and breast milk, and less commonly infant hair, are used for biomonitoring of intra-uterine exposure to these toxic chemicals. Although toxic metals and other pollutants may be excreted into breast milk, their effects are unknown and this topic is subject of a growing body of research. Despite the possibility of harm from environmental contaminants in breast milk, breastfeeding is still recommended as the best infant feeding method. In fact, the species-specific components present in breast milk protect infants against infections; promote immune and neurologic system development; and may decrease the risk of disease, including allergies, obesity, insulin-dependent diabetes mellitus, inflammatory bowel disease, and sudden infant death syndrome. Breastfeeding also facilitates maternal-infant attachment. The potential risk of environmental contaminants that can be transferred from

  1. Compelling Research Opportunities using Isotopes

    Energy Technology Data Exchange (ETDEWEB)

    None

    2009-04-23

    Isotopes are vital to the science and technology base of the US economy. Isotopes, both stable and radioactive, are essential tools in the growing science, technology, engineering, and health enterprises of the 21st century. The scientific discoveries and associated advances made as a result of the availability of isotopes today span widely from medicine to biology, physics, chemistry, and a broad range of applications in environmental and material sciences. Isotope issues have become crucial aspects of homeland security. Isotopes are utilized in new resource development, in energy from bio-fuels, petrochemical and nuclear fuels, in drug discovery, health care therapies and diagnostics, in nutrition, in agriculture, and in many other areas. The development and production of isotope products unavailable or difficult to get commercially have been most recently the responsibility of the Department of Energy's Nuclear Energy program. The President's FY09 Budget request proposed the transfer of the Isotope Production program to the Department of Energy's Office of Science in Nuclear Physics and to rename it the National Isotope Production and Application program (NIPA). The transfer has now taken place with the signing of the 2009 appropriations bill. In preparation for this, the Nuclear Science Advisory Committee (NSAC) was requested to establish a standing subcommittee, the NSAC Isotope Subcommittee (NSACI), to advise the DOE Office of Nuclear Physics. The request came in the form of two charges: one, on setting research priorities in the short term for the most compelling opportunities from the vast array of disciplines that develop and use isotopes and two, on making a long term strategic plan for the NIPA program. This is the final report to address charge 1. NSACI membership is comprised of experts from the diverse research communities, industry, production, and homeland security. NSACI discussed research opportunities divided into three areas: (1

  2. Carbon isotope geochemistry and geobiology

    Science.gov (United States)

    Desmarais, D.

    1985-01-01

    Carbon isotope fractionation values were used to understand the history of the biosphere. For example, plankton analyses confirmed that marine extinctions at the end of the Cretaceous period were indeed severe (see Hsu's article in Sundquist and Broeker, 1984). Variations in the isotopic compositions of carbonates and evaporitic sulfates during the Paleozoic reflect the relative abundances of euxinic (anoxic) marine environments and organic deposits from terrestrial flora. The carbon isotopic composition of Precambrian sediments suggest that the enzyme ribulose bisphosphate carboxylase has existed for perhaps 3.5 billion years.

  3. Isotope-edited infrared spectroscopy.

    Science.gov (United States)

    Buchner, Ginka S; Kubelka, Jan

    2012-01-01

    Isotope-edited infrared (IR) spectroscopy is a powerful tool for studying structural and dynamical properties of peptides and proteins with site-specific resolution. Labeling of selected amide carbonyls with (13)C results in detectable sidebands of amide I' vibrations, which provide information about local conformation and/or solvent exposure without structural perturbation to the protein. Incorporation of isotopically labeled amino acids at specific positions is achieved by the chemical synthesis of the studied proteins. We describe the basic procedures for synthesis of (13)C isotopically edited protein samples, experimental IR spectroscopic measurements, and analysis of the site-specific structural changes from the thermal unfolding IR data.

  4. Induction of cytoprotective autophagy in PC-12 cells by cadmium

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Qiwen [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Bijie Pilot Area Research Institute of Bijie University, Bijie 551700 (China); Zhu, Jiaqiao; Zhang, Kangbao; Jiang, Chenyang; Wang, Yi; Yuan, Yan; Bian, Jianchun; Liu, Xuezhong; Gu, Jianhong [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China); Liu, Zongping, E-mail: liuzongping@yzu.edu.cn [College of Veterinary Medicine, Yangzhou University, Yangzhou 225009 (China); Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009 (China)

    2013-08-16

    Highlights: •Cadmium can promote early upregulation of autophagy in PC-12 cells. •Autophagy precedes apoptosis in cadmium-treated PC-12 cells. •Cadmium-induced autophagy is cytoprotective in PC-12 cells. •Class III PI3K/beclin-1/Bcl-2 signaling pathway plays a positive role in cadmium-triggered autophagy. -- Abstract: Laboratory data have demonstrated that cadmium (Cd) may induce neuronal apoptosis. However, little is known about the role of autophagy in neurons. In this study, cell viability decreased in a dose- and time-dependent manner after treatment with Cd in PC-12 cells. As cells were exposed to Cd, the levels of LC3-II proteins became elevated, specific punctate distribution of endogenous LC3-II increased, and numerous autophagosomes appeared, which suggest that Cd induced a high level of autophagy. In the late stages of autophagy, an increase in the apoptosis ratio was observed. Likewise, pre-treatment with chloroquine (an autophagic inhibitor) and rapamycin (an autophagic inducer) resulted in an increased and decreased percentage of apoptosis in contrast to other Cd-treated groups, respectively. The results indicate that autophagy delayed apoptosis in Cd-treated PC-12 cells. Furthermore, co-treatment of cells with chloroquine reduced autophagy and cell activity. However, rapamycin had an opposite effect on autophagy and cell activity. Moreover, class III PI3 K/beclin-1/Bcl-2 signaling pathways served a function in Cd-induced autophagy. The findings suggest that Cd can induce cytoprotective autophagy by activating class III PI3 K/beclin-1/Bcl-2 signaling pathways. In sum, this study strongly suggests that autophagy may serve a positive function in the reduction of Cd-induced cytotoxicity.

  5. Cadmium burden and the risk and phenotype of prostate cancer

    Directory of Open Access Journals (Sweden)

    Wu Tony T

    2009-12-01

    Full Text Available Abstract Background Studies on the association between prostate cancer and cadmium exposure have yielded conflicting results. This study explored cadmium burden on the risk and phenotype of prostate cancer in men with no evident environmental exposure. Methods Hospital-based 261 prostate cancer cases and 267 controls with benign diseases were recruited from four hospitals in Taiwan. Demographic, dietary and lifestyle data were collected by standardized questionnaires. Blood cadmium (BCd and creatinine-adjusted urine cadmium (CAUCd levels were measured for each participant. Statistical analyses measured the prostate cancer risk associated with BCd and CAUCd separately, controlling for age, smoking and institution. BCd and CAUCd levels within cases were compared in relation to the disease stage and the Gleason score. Results High family income, low beef intake, low dairy product consumption and positive family history were independently associated with the prostate carcinogenesis. There was no difference in BCd levels between cases and controls (median, 0.88 versus 0.87 μg/l, p = 0.45. Cases had lower CAUCd levels than controls (median, 0.94 versus 1.40 μg/g creatinine, p = 0.001. However, cases with higher BCd and CAUCd levels tended to be at more advanced stages and to have higher Gleason scores. The prostate cancer cases with Gleason scores of ≥ 8 had an odds ratio of 2.89 (95% confidence interval 1.25-6.70, compared with patients with scores of 2-6. Conclusion Higher CAUCd and BCd levels may be associated with advanced cancer phenotypes, but there was only a tenuous association between cadmium and prostate cancer.

  6. Physiological characterization of cadmium-exposed Chlamydomonas reinhardtii.

    Science.gov (United States)

    Bräutigam, Anja; Schaumlöffel, Dirk; Preud'homme, Hugues; Thondorf, Iris; Wesenberg, Dirk

    2011-12-01

    Chlamydomonas reinhardtii is a common model organism for investigation of metal stress. This green alga produces phytochelatins in the presence of metal ions. The influence of cadmium is of main interest, because it is a strong activator of phytochelatin synthase. Cell wall bound and intracellular cadmium content was determined after exposition to 70 µm CdCl(2), showing the main portion of the metal outside the cell. Nevertheless, imported cadmium was sufficient to cause significant changes in thiolpeptide metabolism and its transcriptional regulation. Modern analytical approaches enable new insights into phytochelatin (PC) distribution. A new rapid and precise UPLC-MS method allowed high-throughput PC quantification in algal samples after 1, 4, 24 and 48 h cadmium stress. Initially, canonic PCs were synthesized in C. reinhardtii during cadmium exposition, but afterwards CysPCs became the major thiolpeptides. Thus, after 48 h the concentration of the PC-isoforms CysPC(2-3) and CysGSH attained between 105 and 199 nmol g(-1) fresh weight (FW), whereas the PC(2-3) concentrations were only 15 nmol g(-1) FW. The relative quantification of γ-glutamyl transpeptidase (γ-GT) mRNA suggests the generation of CysPCs by glutamate cleavage from canonic PCs by γ-GT. Furthermore, a homology model of C. reinhardtii phytochelatin synthase was constructed to verify the use of crystal structures from Anabaena sp. phytochelatin synthase (PCS) for docking studies with canonical PCs and CysPCs. From the difference in energy scores, we hypothesize that CysPC may prevent the synthesis of canonical PCs by blocking the binding pocket. Finally, possible physiological reasons for the high abundance of CysPC compared with their canonic precursors are discussed.

  7. Apparatus and process for separating hydrogen isotopes

    Science.gov (United States)

    Heung, Leung K; Sessions, Henry T; Xiao, Xin

    2013-06-25

    The apparatus and process for separating hydrogen isotopes is provided using dual columns, each column having an opposite hydrogen isotopic effect such that when a hydrogen isotope mixture feedstock is cycled between the two respective columns, two different hydrogen isotopes are separated from the feedstock.

  8. Analysis of aerospace nickel-cadmium battery cells. [cadmium migration as seen by scanning electron microscopy and metallographic analysis

    Science.gov (United States)

    Eliason, R. R.

    1977-01-01

    Various steps followed in analyzing the electrolyte, separator, and electrodes are reviewed. Specific emphasis is given to scanning electron microscopic and metallographic analysis of the plates. Cadmium migration is defined, its effects and causes are examined, and methods for its reduction in cells are suggested.

  9. Chemical speciation of cadmium: an approach to evaluate plant-available cadmium in Ecuadorian soils under cacao production

    Science.gov (United States)

    Elevated concentration of cadmium (Cd) in cacao beans has raised serious concerns about the safety of chocolate consumption. Accumulation of Cd cacao bean in southern Ecuador has been reported to relate soil contamination. In this study, soil fractionation was conducted to identify available Cd poo...

  10. Cadmium, zinc, and copper in horse liver and in horse liver metallothionein: comparisons with kidney cortex

    Energy Technology Data Exchange (ETDEWEB)

    Elinder, C.G.; Nordberg, M.; Palm, B.; Piscator, M.

    1981-10-01

    Cadmium, zinc, and copper were determined in liver and in kidney cortex samples obtained from 33 normal Swedish horses. Cadmium concentrations in liver ranged from 0.002 to 0.165 mmole/kg and in kidney from 0.01 to 2.15 mmole/kg. There was a significant correlation between liver and kidney concentrations of cadmium. The average kidney concentration of cadmium was about 15 times that of liver. Zinc concentrations increased with increasing cadmium concentrations in both liver and kidney. The relative increase of zinc with cadmium was more pronounced in liver than in kidney. However, the absolute increase of zinc was larger in kidney due to the much higher concentration of cadmium in kidney compared to liver. Any significant correlation between copper and cadmium, or copper and zinc, could not be revealed. Sephadex gel filtration was performed on supernatants from homogenates of kidney and liver from 19 of the horses. In both organs the major part of cadmium was recovered in protein fractions corresponding to metallothionein (MT), in which the increase of zinc also took place. The molar ratio between zinc and cadmium was higher in MT fractions obtained from liver than in MT fractions obtained from kidney.

  11. Effects of Humic Acid on the Germination Traits of Pumpkin Seeds under Cadmium Stress

    Directory of Open Access Journals (Sweden)

    Maasoumeh ASADI

    2013-12-01

    Full Text Available The study tackled the effect of humic acid and cadmium concentrations on the pumpkin seed germination characteristics throughout were studied. Treatments were cadmium concentrations on three levels: 0, 100 and 200 ppm and humic acid concentration of 0, 100, 200, 300 and 400 mg lit-1. Results showed that interaction of humic acid and cadmium was not significant on germination traits, but there was a significant effect on seedling growth indexes. Radicle and plumule length increased by 86 and 192% in comparison with control, of the mixture of 200 ppm cadmium and 300 mg lit-1 of humic acid. Cadmium had stimulatory effect on radicle and cotyledon dry weight and the highest values obtained with 200 ppm in mixture with 200 mg lit-1 of humic acid. Also, maximum plumule dry weight was recorded in 200 ppm cadmium and 300 mg lit-1 of humic acid. The highest of indexes were observed of 200 ppm cadmium and 400 mg lit-1 humic acid. In conclusion, the humic acid had detoxifying effect on cadmium stress in the culture and responded antagonistically against cadmium, but it seems that these concentrations of cadmium are low for the pumpkin seed and can be increased in order to reach the toxicity level.

  12. Chronic cadmium exposure stimulates SDF-1 expression in an ERα dependent manner.

    Science.gov (United States)

    Ponce, Esmeralda; Aquino, Natalie B; Louie, Maggie C

    2013-01-01

    Cadmium is an omnipotent environmental contaminant associated with the development of breast cancer. Studies suggest that cadmium functions as an endocrine disruptor, mimicking the actions of estrogen in breast cancer cells and activating the receptor to promote cell growth. Although acute cadmium exposure is known to promote estrogen receptor-mediated gene expression associated with growth, the consequence of chronic cadmium exposure is unclear. Since heavy metals are known to bioaccumulate, it is necessary to understand the effects of prolonged cadmium exposure. This study aims to investigate the effects of chronic cadmium exposure on breast cancer progression. A MCF7 breast cancer cell line chronically exposed to 10(-7) M CdCl2 serves as our model system. Data suggest that prolonged cadmium exposures result in the development of more aggressive cancer phenotypes - increased cell growth, migration and invasion. The results from this study show for the first time that chronic cadmium exposure stimulates the expression of SDF-1 by altering the molecular interactions between ERα, c-jun and c-fos. This study provides a mechanistic link between chronic cadmium exposure and ERα and demonstrates that prolonged, low-level cadmium exposure contributes to breast cancer progression.

  13. Cadmium promotes breast cancer cell proliferation by potentiating the interaction between ERalpha and c-Jun.

    Science.gov (United States)

    Siewit, Christina L; Gengler, Bridget; Vegas, Esera; Puckett, Rachel; Louie, Maggie C

    2010-05-01

    Cadmium is an environmental contaminant that enters the body through diet or cigarette smoke. It affects multiple cellular processes, including cell proliferation, differentiation, and apoptosis. Recently, cadmium has been shown to function as an endocrine disruptor, to stimulate estrogen receptor alpha (ERalpha) activity and promote uterine and mammary gland growth in mice. Although cadmium exposure has been associated with the development of breast cancer, the mechanism of action of cadmium remains unclear. To address this deficit, we examined the effects of cadmium treatment on breast cancer cells. We found that ERalpha is required for both cadmium-induced cell growth and modulation of gene expression. We also determined that ERalpha translocates to the nucleus in response to cadmium exposure. Additionally, we provide evidence that cadmium potentiates the interaction between ERalpha and c-Jun and enhances recruitment of this transcription factor complex to the proximal promoters of cyclin D1 and c-myc, thus increasing their expression. This study provides a mechanistic link between cadmium exposure and ERalpha and demonstrates that cadmium plays an important role in the promotion of breast cancer.

  14. Chronic cadmium exposure stimulates SDF-1 expression in an ERα dependent manner.

    Directory of Open Access Journals (Sweden)

    Esmeralda Ponce

    Full Text Available Cadmium is an omnipotent environmental contaminant associated with the development of breast cancer. Studies suggest that cadmium functions as an endocrine disruptor, mimicking the actions of estrogen in breast cancer cells and activating the receptor to promote cell growth. Although acute cadmium exposure is known to promote estrogen receptor-mediated gene expression associated with growth, the consequence of chronic cadmium exposure is unclear. Since heavy metals are known to bioaccumulate, it is necessary to understand the effects of prolonged cadmium exposure. This study aims to investigate the effects of chronic cadmium exposure on breast cancer progression. A MCF7 breast cancer cell line chronically exposed to 10(-7 M CdCl2 serves as our model system. Data suggest that prolonged cadmium exposures result in the development of more aggressive cancer phenotypes - increased cell growth, migration and invasion. The results from this study show for the first time that chronic cadmium exposure stimulates the expression of SDF-1 by altering the molecular interactions between ERα, c-jun and c-fos. This study provides a mechanistic link between chronic cadmium exposure and ERα and demonstrates that prolonged, low-level cadmium exposure contributes to breast cancer progression.

  15. The Antartic Ice Borehole Probe

    Science.gov (United States)

    Behar, A.; Carsey, F.; Lane, A.; Engelhardt, H.

    2000-01-01

    The Antartic Ice Borehole Probe mission is a glaciological investigation, scheduled for November 2000-2001, that will place a probe in a hot-water drilled hole in the West Antartic ice sheet. The objectives of the probe are to observe ice-bed interactions with a downward looking camera, and ice inclusions and structure, including hypothesized ice accretion, with a side-looking camera.

  16. Microphthalmia-associated transcription factor as the molecular target of cadmium toxicity in human melanocytes

    Energy Technology Data Exchange (ETDEWEB)

    Chantarawong, Wipa [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan); Inter Departmental Multidisciplinary Graduate Program in Bioscience, Faculty of Science, Kasetsart University, Bangkok (Thailand); Takeda, Kazuhisa; Sangartit, Weerapon; Yoshizawa, Miki [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan); Pradermwong, Kantimanee [Department of Zoology, Faculty of Science, Kasetsart University, Bangkok (Thailand); Shibahara, Shigeki, E-mail: shibahar@med.tohoku.ac.jp [Department of Molecular Biology and Applied Physiology, Tohoku University School of Medicine, Sendai (Japan)

    2014-11-28

    Highlights: • In human melanocytes, cadmium decreases the expression of MITF-M and tyrosinase and their mRNAs. • In human melanoma cells, cadmium decreases the expression of MITF-M protein and tyrosinase mRNA. • Expression of MITF-H is less sensitive to cadmium toxicity in melanocyte-linage cells. • Cadmium does not decrease the expression of MITF-H in retinal pigment epithelial cells. • MITF-M is the molecular target of cadmium toxicity in melanocytes. - Abstract: Dietary intake of cadmium is inevitable, causing age-related increase in cadmium accumulation in many organs, including hair, choroid and retinal pigment epithelium (RPE). Cadmium has been implicated in the pathogenesis of hearing loss and macular degeneration. The functions of cochlea and retina are maintained by melanocytes and RPE, respectively, and the differentiation of these pigment cells is regulated by microphthalmia-associated transcription factor (MITF). In the present study, we explored the potential toxicity of cadmium in the cochlea and retina by using cultured human melanocytes and human RPE cell lines. MITF consists of multiple isoforms, including melanocyte-specific MITF-M and widely expressed MITF-H. Levels of MITF-M protein and its mRNA in human epidermal melanocytes and HMV-II melanoma cells were decreased significantly by cadmium. In parallel with the MITF reduction, mRNA levels of tyrosinase, the key enzyme of melanin biosynthesis that is regulated by MITF-M, were also decreased. In RPE cells, however, the levels of total MITF protein, constituting mainly MITF-H, were not decreased by cadmium. We thus identify MITF-M as the molecular target of cadmium toxicity in melanocytes, thereby accounting for the increased risk of disability from melanocyte malfunction, such as hearing and vision loss among people with elevated cadmium exposure.

  17. Oxygen as a site specific structural probe in neutron diffraction

    Energy Technology Data Exchange (ETDEWEB)

    Neuefeind, Joerg C [ORNL; Simonson, J Michael {Mike} [ORNL; Salmon, Phil [University of Bath; Zeidler, Anita [University of Bath; Fischer, Henry E [Institut Laue-Langevin (ILL); Rauch, Helmut [E141 Atominstitut der & #xD6; sterreichischen Universit& #xE4; ten,; Markland, Thomas [Columbia University; Lemmel, Hartmut [Technical University Vienna

    2011-01-01

    Oxygen is a ubiquitous element, playing an essential role in most scientific and technological disciplines, and is often incorporated within a structurally disordered material where examples include molten silicates in planetary science, glasses used for lasers and optical communication, and water in biological processes. Establishing the structure of a liquid or glassy oxide and thereby its relation to the functional properties of a material is not, however, a trivial task owing to the complexity associated with atomic disorder. Here we approach this challenge by measuring the bound coherent neutron scattering lengths of the oxygen isotopes with the sensitive technique of neutron interferometry. We find that there is a small but finite contrast of 0.204(6) fm between the scattering lengths of the isotope 18O and oxygen of natural isotopic abundance natO, contrary to tables of recommended values. This has enabled us to investigate the structure of both light and heavy water by exploiting, for the first time, the method of oxygen isotope substitution in neutron diffraction, thus circumventing many of the significant problems associated with more traditional methods in which hydrogen is substituted by deuterium. We find a difference of ~0.5% between the O-H and O-D intra-molecular bond distances which is much smaller than recent estimates based on diffraction data and is found to be in excellent agreement with path integral molecular dynamics simulations made with a flexible polarisable water model. Our results demonstrate the potential for using oxygen isotope substitution as a powerful and effective site specific probe in a plethora of materials, of pertinence as instrumentation at next generation neutron sources comes online

  18. Integrating isotopic fingerprinting with petrology: how do igneous rocks evolve?

    Science.gov (United States)

    Davidson, J. P.

    2002-12-01

    In the title of his seminal work, N.L. Bowen recognized the fundamental importance of magmatic evolution in producing the spectrum of igneous rocks. Indeed it is difficult to imagine a hot highly reactive fluid passing through c. 100 km of a chemically distinct medium (lithosphere) without evolving through cooling, crystallization and interaction with the wall rocks. The fact that magmas evolve - almost invariably through open system processes - has been largely marginalized in the past 30 years by the desire to use them as probes of mantle source regions. This perspective has been driven principally by advances offered by isotope geochemistry, through which components and sources can be effectively fingerprinted. Two fundamental observations urge caution in ignoring differentiation effects; 1) the scarcity of truly primary magmas according to geochemical criteria (recognized long ago by petrologists), and 2) the common occurrence of petrographic criteria attesting to open system evolution. Recent advances in multicollector mass spectrometry permit integration of the powerful diagnostic tools of isotope geochemistry with petrographic observations through accurate and precise analysis of small samples. Laser ablation and microdrilling enable sampling within and between mineral phases. The results of our microsampling investigations give widespread support for open system evolution of magmas, and provide insights into the mechanisms and timescales over which this occurs. For example; 1) core-rim decreases in 87Sr/86Sr in zoned plagioclase crystals from 1982 lavas of El Chichon volcano, Mexico, argue that the zoning and isotopic changes are in response to magma recharge mixing with an originally contaminated resident magma; 2) Single grain and intra-grain isotopic analyses of mineral phases from Ngauruhoe andesites (New Zealand) are highly variable, arguing that bulk rock data reflect mechanical aggregations of components which have evolved in discrete domains of the

  19. Alignments in the nobelium isotopes

    Institute of Scientific and Technical Information of China (English)

    ZHENG Shi-Zie; XU Fu-Rong; YUAN Cen-Xi; QI Chong

    2009-01-01

    Total-Routhian-Surface calculations have been performed to investigate the deformation and align-ment properties of the No isotopes. It is found that normal deformed and superdeformed states in these nuclei can coexist at low excitation energies. In neutron-deficient No isotopes, the superdeformed shapes can even become the ground states. Moreover, we plotted the kinematic moments of inertia of the No isotopes, which follow very nicely available experimental data. It is noted that, as the rotational frequency increases, align-ments develop at hω=0.2-0.3 MeV. Our calculations show that the occupation of the vj orbital plays an important role in the alignments of the No isotopes.

  20. Isotopic Changes During Digestion: Protein

    Science.gov (United States)

    Tuross, N.

    2013-12-01

    Nutrient and hydrological inputs traverse a complicated route of pH, enzymatic and cellular processes in digestion in higher animals. The end products of digestion are the starting products for biosynthesis that are often used to interpret past life-ways. Using an artificial gut system, the isotopic changes (dD, d18O, d13C and d15N) of protein are documented. Three separate protein sources are subjected to the conditions, chemical and enzymatic, found in the stomach and upper small intestine with only a small shift in the oxygen isotopic composition of the proteins observed. Middle to lower small intestine parameters produced both greater isotopic effects and significantly lower molecular weight products. The role of the gastric enterocyte and the likely involvement of the internal milieu of this cell in the isotopic composition of amino acids that are transported to the liver are reported.