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Sample records for copper accumulation enhances

  1. INTRACELLULAR COPPER ACCUMULATION ENHANCES THE GROWTH OF KINEOCOCCUS RADIOTOLERANS DURING CHRONIC IRRADIATION

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    Bagwell, C; Charles Milliken, C

    2007-07-24

    The actinobacteria Kineococcus radiotolerans is highly resistant to ionizing radiation, desiccation, and oxidative stress; though the underlying biochemical mechanisms are unknown. The purpose of this study was to explore a possible linkage between the uptake of transition metals and extreme resistance to ionizing radiation and oxidative stress. The effects of 6 different divalent cationic metals on growth were examined in the absence of ionizing radiation. None of the metals tested were stimulatory, though cobalt was inhibitory to growth. In contrast, copper supplementation dramatically increased cell growth during chronic irradiation. K. radiotolerans exhibited specific uptake and intracellular accumulation of copper compared to only a weak response to both iron and manganese supplementation. Copper accumulation sensitized cells to hydrogen peroxide. Acute irradiation induced DNA damage was similar between the copper-loaded culture as the age-synchronized no copper control culture, though low molecular weight DNA was more persistent during post-irradiation recovery in the Cu-loaded culture. Still, the estimated times for genome restoration differed by only 1 hr between treatments. While we cannot discount the possibility that copper fulfills an unexpectedly important biochemical role in a radioactive environment; K. radiotolerans has a high capacity for intracellular copper sequestration, and presumably efficiently coordinated oxidative stress defenses and detoxification systems, which confers cross-protection from the damaging affects ionizing radiation.

  2. Enhanced accumulation of copper and lead in amaranth (Amaranthus paniculatus, Indian mustard (Brassica juncea and sunflower (Helianthus annuus.

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    Motior M Rahman

    Full Text Available BACKGROUND: Soil contamination by copper (Cu and lead (Pb is a widespread environmental problem. For phytoextraction to be successful and viable in environmental remediation, strategies that can improve plant uptake must be identified. In the present study we investigated the use of nitrogen (N fertilizer as an efficient way to enhance accumulation of Cu and Pb from contaminated industrial soils into amaranth, Indian mustard and sunflower. METHODS/PRINCIPAL FINDINGS: Plants were grown in a greenhouse and fertilized with N fertilizer at rates of 0, 190 and 380 mg kg⁻¹ soil. Shoots, roots and total accumulation of Cu and Pb, transfer factor (TF, translocation index were assessed to evaluate the transport and translocation ability of tested plants. Addition of N fertilizer acidified the industrial soil and caused the pH to decrease to 5.5 from an initial pH of 6.9. Industrial soil amended with N fertilizer resulted in the highest accumulation of Pb and Cu (for Pb 10.1-15.5 mg kg⁻¹, for Cu 11.6-16.8 mg kg⁻¹ in the shoots, which was two to four folds higher relative to the concentration in roots in all the three plants used. Sunflower removed significantly higher Pb (50-54% and Cu (34-38% followed by amaranth and Indian mustard from industrial soils with the application of N fertilizer. The TF was <1 while the shoot and root concentration (SC/RC ratios of Pb and Cu were between 1.3-4.3 and 1.8-3.8, respectively, regardless of plant species. CONCLUSIONS: Sunflower is the best plant species to carry out phytoextraction of Pb and Cu. In contrast, Pb and Cu removal by Indian mustard and amaranth shows great potential as quick and short duration vegetable crops. The results suggest that the application of N fertilizer in contaminated industrial soil is an effective amendment for the phytoextraction of Pb and Cu from contaminated industrial soils.

  3. Accumulation and hyperaccumulation of copper in plants

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    Adam, V.; Trnkova, L.; Huska, D.; Babula, P.; Kizek, R.

    2009-04-01

    Copper is natural component of our environment. Flow of copper(II) ions in the environment depends on solubility of compounds containing this metal. Mobile ion coming from soil and rocks due to volcanic activity, rains and others are then distributed to water. Bio-availability of copper is substantially lower than its concentration in the aquatic environment. Copper present in the water reacts with other compounds and creates a complex, not available for organisms. The availability of copper varies depending on the environment, but moving around within the range from 5 to 25 % of total copper. Thus copper is stored in the sediments and the rest is transported to the seas and oceans. It is common knowledge that copper is essential element for most living organisms. For this reason this element is actively accumulated in the tissues. The total quantity of copper in soil ranges from 2 to 250 mg / kg, the average concentration is 30 mg / kg. Certain activities related to agriculture (the use of fungicides), possibly with the metallurgical industry and mining, tend to increase the total quantity of copper in the soil. This amount of copper in the soil is a problem particularly for agricultural production of food. The lack of copper causes a decrease in revenue and reduction in quality of production. In Europe, shows the low level of copper in total 18 million hectares of farmland. To remedy this adverse situation is the increasing use of copper fertilizers in agricultural soils. It is known that copper compounds are used in plant protection against various illnesses and pests. Mining of minerals is for the development of human society a key economic activity. An important site where the copper is mined in the Slovakia is nearby Smolníka. Due to long time mining in his area (more than 700 years) there are places with extremely high concentrations of various metals including copper. Besides copper, there are also detected iron, zinc and arsenic. Various plant species

  4. Dietary Management of Labrador Retrievers with Subclinical Hepatic Copper Accumulation

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    Fieten, H.; Biourge, V.C.; Watson, A.L.; Leegwater, P.A.J.; van den Ingh, T.S.G.A.M.; Rothuizen, J.

    2015-01-01

    Background Genetic and environmental factors, including dietary copper intake, contribute to the pathogenesis of copper‐associated hepatitis in Labrador retrievers. Clinical disease is preceded by a subclinical phase in which copper accumulates in the liver. Objective To investigate the effect of a low‐copper, high‐zinc diet on hepatic copper concentration in Labrador retrievers with increased hepatic copper concentrations. Animals Twenty‐eight clinically healthy, client‐owned Labrador retrie...

  5. Impacts of ambient salinity and copper on brown algae: 1. Interactive effects on photosynthesis, growth, and copper accumulation.

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    Connan, Solène; Stengel, Dagmar B

    2011-07-01

    The effect of copper enrichment and salinity on growth, photosynthesis and copper accumulation of two temperate brown seaweeds, Ascophyllum nodosum and Fucus vesiculosus, was investigated in laboratory experiments. A significant negative impact of reduced salinity on photosynthetic activity and growth was observed for both species. After 15 days at a salinity of 5, photosynthesis of A. nodosum was entirely inhibited and growth ceased at a salinity of 15. Increased copper concentration negatively affected photosynthetic activity of A. nodosum and F. vesiculosus resulting in chlorosis and reduced seaweed growth; 5 mg L⁻¹ copper caused an inhibition of the photosynthesis and the degradation of seaweed tips. Under reduced salinity, copper toxicity was enhanced and caused an earlier impact on the physiology of seaweed tips. After exposure to copper and different salinities for 15 days, copper contents of seaweeds were closely related to copper concentration in the water; seaweed copper contents reached their maximum after 1 day of exposure; contents only increased again when additional, free copper was added to the water. At high water copper concentrations or low salinity, or a combination of both, copper content of A. nodosum decreased. By contrast, copper content of F. vesiculosus increased, suggesting that different binding sites or uptake mechanisms exist in the two species. The results suggest that when using brown seaweeds in biomonitoring in situ, any change in the environment will directly and significantly affect algal physiology and thus their metal binding capacity; the assessment of the physiological status of the algae in combination with the analysis of thallus metal content will enhance the reliability of the biomonitoring process. Copyright © 2011 Elsevier B.V. All rights reserved.

  6. Dietary Management of Hepatic Copper Accumulation in Labrador Retrievers

    NARCIS (Netherlands)

    Hoffmann, G.; jones, P.G.; Biourge, V.; van den Ingh, T.S.G.A.M.; Mesu, bode; Bode, P.; Rothuizen, J.

    2009-01-01

    J Vet Intern Med. 2009 Sep-Oct;23(5):957-63. Epub 2009 Jul 14. Dietary management of hepatic copper accumulation in Labrador Retrievers. Hoffmann G, Jones PG, Biourge V, van den Ingh TS, Mesu SJ, Bode P, Rothuizen J. Department of Clinical Sciences of Companion Animals, Faculty of Veterinary Medicin

  7. Three stages of copper accumulation in hepatocellular lysosomes: X-ray microanalysis of copper-loaded golden hamsters.

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    Yagi, A.; Hayashi, H; Higuchi, T.; Hishida, N.; Sakamoto, N.

    1992-01-01

    Male golden hamsters were loaded with copper by supplying them for up to 12 weeks with drinking water containing 0.5% cupric acetate. The copper feeding increased hepatic copper to widely varying levels. Energy dispersive X-ray microanalysis could always identify a copper-sulphur complex in the hepatocyte lysosomes of copper-loaded hamsters and the X-ray intensity of copper was found to be a reliable parameter to measure in-situ copper accumulation. Combining this parameter with the copper bi...

  8. Accumulation and ultrastructural distribution of copper in Elsholtzia splendens

    Institute of Scientific and Technical Information of China (English)

    PENG Hong-yun; YANG Xiao-e; TIAN Sheng-ke

    2005-01-01

    Copper accumulation and intracellular distribution in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species, was investigated by transmission electron microscope (TEM) and gradient centrifugation techniques.Copper concentrations in roots, stems and leaves of E. splendens increased with increasing Cu levels in solution. After exposure to 500 μmol/L Cu for 8 d, about 1000 mg/kg Cu were accumulated in the stem and 250 mg/kg Cu in the leaf of E. splendens. At 50μmol/L Cu, no significant toxicity was observed in the chloroplast and mitochondrion within its leaf cells, but separation appeared at the cytoplasm and the cell wall within the root cells. At >250 μmol/L Cu, both root and leaf organelles in E. splendens were damaged heavily by excessive Cu in vivo. Copper subcellular localization in the plant leaf after 8 days' exposure to 500 μmol/L Cu using gradient centrifugation techniques was found to be decreased in the order: chloroplast>cell wall>soluble fraction>other organelles. The plant root cell wall was found to be the site of highest Cu localization. Increase of Cu exposure time from 8 d to 16d, increased slightly Cu concentration in cell wall fraction in roots and leaves, while that in the chloroplast fraction decreased in leaves of the plants grown in both 0.25 μmol/L and 500 μmol/L Cu. TEM confirmed that much more Cu localized in cell walls of E. splendens roots and leaves, but also more Cu localized in E. splendens' chloroplast when the plant is exposed to Cu levels>250μmol/L, as compared to those in the plant grown in 0.25 μmol/L Cu. Copper treatment at levels>250 μmol/L caused pronounced damage in the leaf chloroplast and root organelles. Copper localization in cell walls and chloroplasts could mainly account for the high detoxification of Cu in E. splendens.

  9. Copper-resistant bacteria enhance plant growth and copper phytoextraction.

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    Yang, Renxiu; Luo, Chunling; Chen, Yahua; Wang, Guiping; Xu, Yue; Shen, Zhenguo

    2013-01-01

    In this study, we investigated the role of rhizospheric bacteria in solubilizing soil copper (Cu) and promoting plant growth. The Cu-resistant bacterium DGS6 was isolated from a natural Cu-contaminated soil and was identified as Pseudomonas sp. DGS6. This isolate solubilized Cu in Cu-contaminated soil and stimulated root elongation of maize and sunflower. Maize was more sensitive to inoculation with DGS6 than was sunflower and exhibited greater root elongation. In pot experiment, inoculation with DGS6 increased the shoot dry weight of maize by 49% and sunflower by 34%, and increased the root dry weight of maize by 85% and sunflower by 45%. Although the concentrations of Cu in inoculated and non-inoculated seedlings did not differ significantly, the total accumulation of Cu in the plants increased after inoculation. DGS6 showed a high ability to solubilize P and produce iron-chelating siderophores, as well as significantly improved the accumulation of P and Fe in both maize and sunflower shoots. In addition, DGS6 produced indole-3-acetic acid (IAA) and ACC deaminase, which suggests that it may modulate ethylene levels in plants. The bacterial strain DGS6 could be a good candidate for re-vegetation of Cu-contaminated sites. Supplemental materials are available for this article. Go to the publisher's online edition of International Journal of Phytoremediation to view the supplemental file.

  10. Betacyanin accumulation and guaiacol peroxidase activity in Beta vulgaris L. leaves following copper stress

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    Janet M. León Morales

    2012-07-01

    Full Text Available The effect of copper stress on betacyanin accumulation and guaiacol peroxidase (GPOD activity in leaves of different age was evaluated in red beet (Beta vulgaris L. var. Crosby Egyptian plants. In hydroponic culture, plants were treated with 0.3 μM (control, 50 μM, 100 μM, and 250 μM of CuSO4 for 6 days. Copper was taken up and accumulated in old roots but was not translocated to leaves. However in young leaves, the increase of lipid peroxidation and reduction of growth were evident from day 3 of copper exposure; whereas in old leaves, the lipid peroxidation and growth were the same from either copper-treated or control plants. In response to copper exposure, the betacyanin accumulation was evident in young leaves by day 3, and continued to increase until day 6. Betacyanin only were accumulated in old leaves until day 6, but the contents were from 4 to 5 times lower than those observed in young leaves at the same copper concentrations. GPOD activity increased 3.3- and 1.4-fold in young and old leaves from day 3 of copper treatment respectively, but only in the young leaves was sustained at the same level until day 6. Old roots shown betacyanin in the control plants, but the betacyanin level and growth were reduced with the copper exposure. In contrast, young roots emerged by copper effect also accumulated copper and showed the highest betacyanin content of all plant parts assayed. These results indicate that betacyanin accumulation and GPOD activity are defense responses to copper stress in actively growing organs.

  11. VARIABILITY OF COORDINATION COMPLEXES OF COPPER ACCUMULATED WITHIN FUNGAL COLONY IN THE PRESENCE OF COPPER-CONTAINING MINERALS

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    M. O. Fomina

    2014-04-01

    Full Text Available The aim of work was to elucidate the mechanisms of bioaccumulation of copper leached from minerals by fungus Aspergillus niger with great bioremedial potential due to its ability to produce chelating metabolites and transform toxic metals and minerals. The special attention was paid to the chemical speciation of copper bioaccumulated within fungal colony in the process of fungal transformation of copper-containing minerals. Chemical speciation of copper within different parts of the fungal colony was studied using solid-state chemistry methods such as synchrotron-based X-ray absorption spectroscopy providing information about the oxidation state of the target element, and its coordination environment. The analysis of the obtained X-ray absorption spectroscopy spectra was carried out using Fourier transforms of Extended X-ray Absorption Fine Structure regions, which correspond to the oscillating part of the spectrum to the right of the absorption edge. Results of this study showed that fungus A. niger was involved in the process of solubilization of copper-containing minerals resulted in leaching of mobile copper and its further immobilization by fungal biomass with variable coordination of accumulated copper within fungal colony which depended on the age and physiological/reproductive state of fungal mycelium. X-ray absorption spectroscopy data demonstrated that copper accumulated within outer zone of fungal colony with immature vegetative mycelium was coordinated with sulphur–containing ligands, in contrast to copper coordination with phosphate ligands within mature mycelium with profuse conidia in the central zone of the colony. The findings of this study not only broaden our understanding of the biogeochemical role of fungi but can also be used in the development of various fungal-based biometallurgy technologies such as bioremediation, bioaccumulation and bioleaching and in the assessment of their reliability. The main conclusion is that

  12. Nitrogen substituent polarity influences dithiocarbamate-mediated lipid oxidation, nerve copper accumulation, and myelin injury.

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    Valentine, Holly L; Viquez, Olga M; Amarnath, Kalyani; Amarnath, Venkataraman; Zyskowski, Justin; Kassa, Endalkachew N; Valentine, William M

    2009-01-01

    Dithiocarbamates have a wide spectrum of applications in industry, agriculture, and medicine, with new applications being investigated. Past studies have suggested that the neurotoxicity of some dithiocarbamates may result from copper accumulation, protein oxidative damage, and lipid oxidation. The polarity of a dithiocarbamate's nitrogen substituents influences the lipophilicity of the copper complexes that it generates and thus potentially determines its ability to promote copper accumulation within nerve and induce myelin injury. In the current study, a series of dithiocarbamate-copper complexes differing in their lipophilicity were evaluated for their relative abilities to promote lipid peroxidation determined by malondialdehyde levels generated in an ethyl arachidonate oil-in-water emulsion. In a second component of this study, rats were exposed to either N,N-diethyldithiocarbamate or sarcosine dithiocarbamate; both generated dithiocarbamate-copper complexes that were lipid- and water-soluble, respectively. Following the exposures, brain, tibial nerve, spinal cord, and liver tissue copper levels were measured by inductively coupled mass spectroscopy to assess the relative abilities of these two dithiocarbamates to promote copper accumulation. Peripheral nerve injury was evaluated using grip strengths, nerve conduction velocities, and morphologic changes at the light microscope level. Additionally, the protein expression levels of glutathione transferase alpha and heme-oxygenase-1 in nerve were determined, and the quantity of protein carbonyls was measured to assess levels of oxidative stress and injury. The data provided evidence that dithiocarbamate-copper complexes are redox active and that the ability of dithiocarbamate complexes to promote lipid peroxidation is correlated to the lipophilicity of the complex. Consistent with neurotoxicity requiring the formation of a lipid-soluble copper complex, significant increases in copper accumulation, oxidative

  13. Copper Deficiency in Sheep with High Liver Iron Accumulation

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    Isadora Karolina Freitas de Sousa

    2012-01-01

    Full Text Available An outbreak of enzootic ataxia among sheep raised in the northeastern region of Brazil is described. Copper (Cu deficiency was diagnosed in a herd of 56 sheep, among which five presented characteristic clinical symptoms of enzootic ataxia. The symptoms began 30 days after birth, with a clinical condition that included locomotion difficulty, limb ataxia, tremors, and continual falls. Liver biopsies were performed and blood was collected to determine hepatic and plasmatic Cu, iron (Fe, and zinc (Zn concentration, respectively. The laboratory results showed that the animals presented low copper concentrations in the plasma and liver, without difference between the clinically healthy animals and those affected by enzootic ataxia. Even after supplementation with adequate Cu levels had been recommended, it was found on a new visit to the farm four months later that one animal still presented a clinical condition and that the hepatic Cu levels of the herd had not risen. Despite the low copper content of the diet, the high hepatic Fe levels found suggest that antagonism due to this element may have been an important factor in triggering copper deficiency in these animals, and thus, additional copper supplementation may be necessary for these animals.

  14. Accumulation of copper and zinc by balanus amphitrite in a tropical estuary

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    Anil, A.C.; Wagh, A.B.

    @iBalanus amphitrite@@ (Cirripedia: Thoracica) a dominant fouling organism was analysed to assess the accumulation potentialities of copper and zinc. It was observed that it could accumulate Cu to 864.77 mu g g-1 dry wt. and Zn to 1937.50 mu g g-1...

  15. Hepatic Copper Accumulation: A Novel Feature in Transient Infantile Liver Failure Due to TRMU Mutations?

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    Grover, Z; Lewindon, P; Clousten, A; Shaag, A; Elpeleg, O; Coman, D

    2015-01-01

    Defects in the mitochondrial respiratory chain can induce a heterogeneous range of clinical and biochemical manifestations. Hepatic involvement includes acute fulminant hepatic failure, microvesicular steatosis, neonatal non-alloimmune haemochromatosis and cirrhosis. Recently pathogenic mutations in tRNA 5-methylaminomethyl-2-thiouridylate methyltransferase (TRMU) gene (OMIM 610230) have been demonstrated to cause transient infantile liver failure (OMIM 613070). The human TRMU gene encodes a mitochondrial protein, 5-methylaminomethyl-2-thiouridylate methyltransferase, whose molecular function is that of mitochondrial tRNA modification.We report an infant who presented with acute liver failure, in whom we observed hepatic copper intoxication and cirrhosis on liver biopsy. We postulate that the hepatic copper intoxication observed in our patient is most likely a secondary event associated with cholangiopathy. Periportal copper accumulation has been implicated in causing secondary mitochondrial dysfunction; the impact of copper accumulation in patients with TRMU mutations is unclear and warrants long-term clinical follow-up.

  16. Complexation and Toxicity of Copper in Higher Plants. I. Characterization of Copper Accumulation, Speciation, and Toxicity in Crassula helmsii as a New Copper Accumulator1[W][OA

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    Küpper, Hendrik; Götz, Birgit; Mijovilovich, Ana; Küpper, Frithjof C.; Meyer-Klaucke, Wolfram

    2009-01-01

    The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up to more than 9,000 ppm in its shoots at 10 μm (=0.6 ppm) Cu2+ in the nutrient solution, indicating that it is a Cu hyperaccumulator. We investigated uptake, binding environment, and toxicity of Cu in this plant under emerged and submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed that Cu was bound almost exclusively by oxygen ligands, likely organic acids, and not any sulfur ligands. Despite significant differences in photosynthesis biochemistry and biophysics between emerged and submerged plants, no differences in Cu ligands were found. While measurements of tissue pH confirmed the diurnal acid cycle typical for Crassulacean acid metabolism, Δ13C measurements showed values typical for regular C3 photosynthesis. Cu-induced inhibition of photosynthesis mainly affected the photosystem II (PSII) reaction center, but with some unusual features. Most obviously, the degree of light saturation of electron transport increased during Cu stress, while maximal dark-adapted PSII quantum yield did not change and light-adapted quantum yield of PSII photochemistry decreased particularly in the first 50 s after onset of actinic irradiance. This combination of changes, which were strongest in submerged cultures, shows a decreasing number of functional reaction centers relative to the antenna in a system with high antenna connectivity. Nonphotochemical quenching, in contrast, was modified by Cu mainly in emerged cultures. Pigment concentrations in stressed plants strongly decreased, but no changes in their ratios occurred, indicating that cells either survived intact or died and bleached quickly. PMID:19641032

  17. Complexation and toxicity of copper in higher plants. I. Characterization of copper accumulation, speciation, and toxicity in Crassula helmsii as a new copper accumulator.

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    Küpper, Hendrik; Götz, Birgit; Mijovilovich, Ana; Küpper, Frithjof C; Meyer-Klaucke, Wolfram

    2009-10-01

    The amphibious water plant Crassula helmsii is an invasive copper (Cu)-tolerant neophyte in Europe. It now turned out to accumulate Cu up to more than 9,000 ppm in its shoots at 10 microm (=0.6 ppm) Cu(2+) in the nutrient solution, indicating that it is a Cu hyperaccumulator. We investigated uptake, binding environment, and toxicity of Cu in this plant under emerged and submerged conditions. Extended x-ray absorption fine structure measurements on frozen-hydrated samples revealed that Cu was bound almost exclusively by oxygen ligands, likely organic acids, and not any sulfur ligands. Despite significant differences in photosynthesis biochemistry and biophysics between emerged and submerged plants, no differences in Cu ligands were found. While measurements of tissue pH confirmed the diurnal acid cycle typical for Crassulacean acid metabolism, Delta(13)C measurements showed values typical for regular C3 photosynthesis. Cu-induced inhibition of photosynthesis mainly affected the photosystem II (PSII) reaction center, but with some unusual features. Most obviously, the degree of light saturation of electron transport increased during Cu stress, while maximal dark-adapted PSII quantum yield did not change and light-adapted quantum yield of PSII photochemistry decreased particularly in the first 50 s after onset of actinic irradiance. This combination of changes, which were strongest in submerged cultures, shows a decreasing number of functional reaction centers relative to the antenna in a system with high antenna connectivity. Nonphotochemical quenching, in contrast, was modified by Cu mainly in emerged cultures. Pigment concentrations in stressed plants strongly decreased, but no changes in their ratios occurred, indicating that cells either survived intact or died and bleached quickly.

  18. Copper Transporter 2 Regulates the Cellular Accumulation and Cytotoxicity of Cisplatin and Carboplatin

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    Blair, Brian G.; Larson, Christopher A.; Safaei, Roohangiz; Howell, Stephen B.

    2010-01-01

    Purpose Copper transporter 2 (CTR2) is known to mediate the uptake of Cu+1 by mammalian cells. Several other Cu transporters, including the influx transporter CTR1 and the two efflux transporters ATP7A and ATP7B, also regulate sensitivity to the platinum-containing drugs. We sought to determine the effect of CTR2 on influx, intracellular trafficking, and efflux of cisplatin and carboplatin. Experimental Design The role of CTR2 was examined by knocking down CTR2 expression in an isogenic pair of mouse embryo fibroblasts consisting of a CTR1+/+ line and a CTR1−/− line in which both CTR1 alleles had been deleted. CTR2 levels were determined by quantitative reverse transcription-PCR and Western blot analysis. Cisplatin (DDP) was quantified by inductively coupled plasma mass spectrometry and 64Cu and [14C]carboplatin (CBDCA) accumulation by γ and scintillation counting. Results Deletion of CTR1 reduced the uptake of Cu, DDP, and CBDCA and increased resistance to their cytotoxic effects by 2- to 3-fold. Knockdown of CTR2 increased uptake of Cu only in the CTR1+/+ cells. In contrast, knockdown of CTR2 increased whole-cell DDP uptake and DNA platination in both CTR1+/+ and CTR1−/− cells and proportionately enhanced cytotoxicity while producing no effect on vesicular accumulation or efflux. A significant correlation was found between CTR2 mRNA and protein levels and sensitivity to DDP in a panel of six ovarian carcinoma cell lines. Conclusions CTR2 is a major determinant of sensitivity to the cytotoxic effects of DDP and CBDCA. CTR2 functions by limiting drug accumulation, and its expression correlates with the sensitivity of human ovarian carcinoma cell lines to DDP. PMID:19509135

  19. ANTIMICROBIAL ACTIVITY OF COPPER AND ZINC ACCUMULATED BY EASTERN OYSTER AMEBOCYTES

    Science.gov (United States)

    Fisher, William S. Submitted. Antimicrobial Activity of Copper and Zinc Accumulated by Eastern Oyster Amebocytes. J. Shellfish Res. 54 p. (ERL,GB 1196). The distribution of eastern oysters Crassostrea virginica near terrestrial watersheds has led to a general impression t...

  20. Combined effects of water flow and copper concentration on the feeding behavior, growth rate, and accumulation of copper in tissue of the infaunal polychaete Polydora cornuta.

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    Colvin, Marienne A; Hentschel, Brian T; Deheyn, Dimitri D

    2016-12-01

    We performed an experiment in a laboratory flume to test the effects of water flow speed and the concentration of aqueaous copper on the feeding behavior, growth rate, and accumulation of copper in the tissues of juvenile polychaetes Polydora cornuta. The experiment included two flow speeds (6 or 15 cm/s) and two concentrations of added copper (0 or 85 μg/L). Worms grew significantly faster in the faster flow and in the lower copper concentration. In the slower flow, the total time worms spent feeding decreased significantly as copper concentration increased, but copper did not significantly affect the time worms spent feeding in the faster flow. Across all treatments, there was a significant, positive relationship between the time individuals spent feeding and their relative growth rate. Worms were observed suspension feeding significantly more often in the faster flow and deposit feeding significantly more often in the slower flow, but copper concentration did not affect the proportion of time spent in either feeding mode. The addition of 85 μg/L copper significantly increased copper accumulation in P. cornuta tissue, but the accumulation did not differ significantly due to flow speed. There was a significant interaction between copper and flow; the magnitude of the difference in copper accumulation between the 0 and 85 μg/L treatments was greater in the faster flow than in the slower flow. In slow flows that favor deposit feeding, worms grow slowly and accumulate less copper in their tissue than in faster flows that favor suspension feeding and faster growth.

  1. Variation in copper and zinc tolerance and accumulation in 12 willow clones: implications for phytoextraction.

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    Yang, Wei-dong; Wang, Yu-yan; Zhao, Feng-liang; Ding, Zhe-li; Zhang, Xin-cheng; Zhu, Zhi-qiang; Yang, Xiao-e

    2014-09-01

    Willows (Salix spp.) have shown high potential for the phytoextraction of heavy metals. This study compares variations in copper (Cu) and zinc (Zn) tolerance and accumulation potential among 12 willow clones grown in a nutrient solution treated with 50 μmol/L of Cu or Zn, respectively. The results showed differences in the tolerance and accumulation of Cu and Zn with respect to different species/clones. The biomass variation among clones in response to Cu or Zn exposure ranged from the stimulation of growth to inhibition, and all of the clones tested showed higher tolerance to Cu than to Zn. The clones exhibited less variation in Cu accumulation but larger variation in Zn accumulation. Based on translocation factors, it was found that most of the Cu was retained in the roots and that Zn was more mobile than Cu for all clones. It is concluded that most willow clones are good accumulators of Zn and Cu.

  2. Soil Copper and Zinc Accumulation and Bioavailability under a Long Term Vineyard Cultivation in South Italy

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    Anna Maria Corea

    2007-03-01

    Full Text Available Soil metal contamination, particularly by copper, is a phenomenon which often occurs in the surface layer of vineyard soils, due to the widespread application of Cu-based products in the plant disease management. Our study was focused on soil Cu and Zn accumulation and bioavailability as related to some soil properties under a long term vineyard cultivation, in a D.O.C. wine area of South Italy (Calabria region. Soils selected from different landscape units, ranging from acid to alkaline, under homogeneous climate conditions and vineyard management system, were investigated. Each soil was sampled in both a vineyard and a fallow area, at the depth levels of 0-10 cm, 10-25 cm and 25-50 cm. The experimental data were analysed by ANOVA, correlation and multiple stepwise regression procedures. As expected, the results indicated a contamination of the vineyard soils by Cu due to the repeated application of Cu-based products in the plant disease control, with increments of total Cu content up to 150% against the fallow soils. On the contrary, the results led to exclude any soil Zn pollution due to the vineyard management and to suppose a main pedogenic origin for this metal. According to the relationships between Cu content and soil properties, Cu accumulation was promoted by higher pH, clay and organic matter contents. These soil properties also showed a strong influence on metal bioavailability, which underwent a significant reduction in soils with higher pH and clay contents. A further result of great significance was the adverse impact of soil erosion, enhanced by the application of not suitable management systems in hilly areas, on soil capability to retain polluting metals. Soil pH, organic matter content and texture, as well as soil management system, are key factors in soil capability to limit polluting metal dispersion in the environment.

  3. Soil Copper and Zinc Accumulation and Bioavailability under a Long Term Vineyard Cultivation in South Italy

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    Anna Maria Corea

    2011-02-01

    Full Text Available Soil metal contamination, particularly by copper, is a phenomenon which often occurs in the surface layer of vineyard soils, due to the widespread application of Cu-based products in the plant disease management. Our study was focused on soil Cu and Zn accumulation and bioavailability as related to some soil properties under a long term vineyard cultivation, in a D.O.C. wine area of South Italy (Calabria region. Soils selected from different landscape units, ranging from acid to alkaline, under homogeneous climate conditions and vineyard management system, were investigated. Each soil was sampled in both a vineyard and a fallow area, at the depth levels of 0-10 cm, 10-25 cm and 25-50 cm. The experimental data were analysed by ANOVA, correlation and multiple stepwise regression procedures. As expected, the results indicated a contamination of the vineyard soils by Cu due to the repeated application of Cu-based products in the plant disease control, with increments of total Cu content up to 150% against the fallow soils. On the contrary, the results led to exclude any soil Zn pollution due to the vineyard management and to suppose a main pedogenic origin for this metal. According to the relationships between Cu content and soil properties, Cu accumulation was promoted by higher pH, clay and organic matter contents. These soil properties also showed a strong influence on metal bioavailability, which underwent a significant reduction in soils with higher pH and clay contents. A further result of great significance was the adverse impact of soil erosion, enhanced by the application of not suitable management systems in hilly areas, on soil capability to retain polluting metals. Soil pH, organic matter content and texture, as well as soil management system, are key factors in soil capability to limit polluting metal dispersion in the environment.

  4. COPPER ACCUMULATION IN SOILS AND VEGETATION OF POLLUTED AREA COPŞA MICĂ

    Directory of Open Access Journals (Sweden)

    Nicoleta Vrînceanu

    2010-01-01

    Full Text Available The study carried out in order to estimate the distribution and accumulation of copper in soils and vegetation fromCopşa Mică area used a radial network centered in the source of pollution – S.C. SOMETRA S.A. Copşa Mică. Soil andplant samples taken from the radial nodes of the network were analyzed to determine the content of copper. Values ofcopper content in plant ranged between 4.2 mg/kg and 97 mg/kg. Based on these results has been obtained a regressionequation that estimates the copper content in plants as function of the total copper content in soil. The spontaneousvegetation developed in the investigated area includes plants belonging to the following species: Amaranthusretroflexus, Artemisia vulgaris, Asclepias syriaca, Calamagrostis epigeios, Calamagrostis pseudophragmites, Cynodondactylon, Daucus carota, Equisetum arvense, Phragmites australis, Picris hieracioides, Setaria glauca, Sinapisarvensis, Verbascum phlomoides and Xanthium strumarium. The copper pollution doesn’t represent a major problem inCopşa Mică area.

  5. Trehalose accumulation enhances tolerance of Saccharomyces cerevisiae to acetic acid.

    Science.gov (United States)

    Yoshiyama, Yoko; Tanaka, Koichi; Yoshiyama, Kohei; Hibi, Makoto; Ogawa, Jun; Shima, Jun

    2015-02-01

    Trehalose confers protection against various environmental stresses on yeast cells. In this study, trehalase gene deletion mutants that accumulate trehalose at high levels showed significant stress tolerance to acetic acid. The enhancement of trehalose accumulation can thus be considered a target in the breeding of acetic acid-tolerant yeast strains.

  6. Effect of organic complexation on copper accumulation and toxicity to the estuarine red macroalga Ceramium tenuicorne: a test of the free ion activity model.

    Science.gov (United States)

    Ytreberg, Erik; Karlsson, Jenny; Hoppe, Sabina; Eklund, Britta; Ndungu, Kuria

    2011-04-01

    Current water quality criteria (WQC) regulations on copper toxicity to biota are still based on total dissolved (MINTEQ incorporating the Stockholm Humic Model) show that copper accumulation in C. tenuicorne only correlates linearly well to [Cu2+] at relatively high [Cu2+] and in the absence of fulvic acid. Thus the FIAM fails to describe copper accumulation in C. tenuicorne at copper and DOC concentrations typical of most marine waters. These results seem to indicate that at ambient total dissolved copper concentration in coastal and estuarine waters, C. tenuicorne might be able to access a sizable fraction of organically complexed copper when free copper concentration to the cell membrane is diffusion limited.

  7. Influences of petroleum on accumulation of copper and cadmium in the polychaete Nereis diversicolor

    Institute of Scientific and Technical Information of China (English)

    SUN Fu-hong; ZHOU Qi-xing; ZHANG Qian-ru

    2006-01-01

    Using the exposure simulation experiment, the action of petroleum affecting the accumulation of the trace metals including copper (Cu) and cadmium (Cd) in littoral polychaete Nereis diversicolor collected from the Shuangtaizi Estuary in Liaoning Province,China was examined. The results showed that there was a markedly non-linear relationship between the accumulation of Cu in worms and the experimental concentration of Cu in exposure solutions when the concentration of petroleum remained at 0, 100, and 220 μl/L, respectively. However, significantly non-linear relationship for worms exposed to Cd was observed only when the concentration of added petroleum was 0 and 220 μl/L. The accumulation of Cu in worms did not differ significantly among the three different levels of petroleum concentrations combined with various concentrations of Cu. So was the accumulation of Cd in worms (p>0.05).However, the addition of petroleum in exposure solutions brought about an increase in the accumulation of Cu in Nereis diversicolor,in comparison with single Cu pollution. On the other hand, when the concentration of added petroleum remained at 100 μl/L, the accumulation of Cd in worms was lower than that in worms exposed to various concentrations of only cadmium. However, the worms exposed to Cd and petroleum 220 μl/L did not show obvious and identical increase in the accumulation of Cd, compared with single Cd exposure. The accumulation of both Cu and Cd in worms did not increase significantly with the increases in concentrations of Cu or Cd in exposure solutions combined with petroleum (0, 100, and 220 μl/L) under the experimental conditions. Although Nereis diversicolor is exposed to very high Cu and Cd in exposure solutions, accumulation and detoxification mechanisms are sufficient to cope with the extra metal influx in order to survive.

  8. Nano-TiO{sub 2} enhances the toxicity of copper in natural water to Daphnia magna

    Energy Technology Data Exchange (ETDEWEB)

    Fan Wenhong, E-mail: fanwh@buaa.edu.cn [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Cui Minming [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China); Liu Hong; Wang Chuan [Research Center for Green Chemistry and Engineering, School of Chemistry and Chemical Engineering, Sun Yat-sen University, Guangzhou 510275 (China); Shi Zhiwei; Tan Cheng; Yang Xiuping [Department of Environmental Science and Engineering, School of Chemistry and Environment, Beihang University, Beijing 100191 (China)

    2011-03-15

    The acute toxicity of engineered nanoparticles (NPs) in aquatic environments at high concentrations has been well-established. This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna by increasing the copper bioaccumulation. Specifically, at 2 mg L{sup -1} nano-TiO{sub 2}, the (LC{sub 50}) of Cu{sup 2+} concentration observed to kill half the population, decreased from 111 {mu}g L{sup -1} to 42 {mu}g L{sup -1}. Correspondingly, the level of metallothionein decreased from 135 {mu}g g{sup -1} wet weight to 99 {mu}g g{sup -1} wet weight at a Cu{sup 2+} level of 100 {mu}g L{sup -1}. The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the animals, thereby causing toxic injury. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification by metallothioneins. - Research highlights: > This study demonstrates that, at a concentration generally considered to be safe in the environment, nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. > The copper was found to be adsorbed onto the nano-TiO{sub 2}, and ingested and accumulated in the Daphnia magna, thereby causing toxic injury. > The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein. - The nano-TiO{sub 2} remarkably enhanced the toxicity of copper to Daphnia magna. The nano-TiO{sub 2} may compete for free copper ions with sulfhydryl groups, causing the inhibition of the detoxification mechanism of metallothionein.

  9. Enhancement of uranium-accumulating ability of microorganisms by irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Sakaguchi, Takashi; Nakajima, Akira; Tsuruta, Takehiko [Miyazaki Medical Coll., Kiyotake (Japan)

    1998-01-01

    Some microorganisms having excellent ability to accumulate uranium were isolated, from soil and water systems in and around the Ningyo-toge Station of Power Reactor and Nuclear Fuel Development Corporation. The enhancement of uranium-accumulating ability of microorganisms by electron-beam irradiation was examined, and the ability of JW-046 was increased 3-5% by the irradiation. The irradiation affect the growth of some of microorganisms tested. (author)

  10. [Combined effects of copper and simulated acid rain on copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa].

    Science.gov (United States)

    He, Shan-Ying; Gao, Yong-Jie; Shentu, Jia-Li; Chen, Kun-Bai

    2011-02-01

    A pot experiment was conducted to study the combined effects of Cu (0-1500 mg x kg(-1)) and simulated acid rain (pH 2.5-5.6) on the copper accumulation, growth, and antioxidant enzyme activities of Rumex acetosa. With the increasing concentration of soil Cu, the Cu accumulation in R. acetosa increased, being higher in root than in stem and leaf. The exposure to low pH acid rain promoted the Cu uptake by R. acetosa. With the increase of soil Cu concentration and/or of acid rain acidity, the biomass of R. acetosa decreased, leaf and root MDA contents increased and had good correlation with soil Cu concentration, and the SOD and POD activities in leaf and root displayed a decreasing trend after an initial increase. This study showed that R. acetosa had a strong adaptive ability to Cu and acid rain stress, exhibiting a high application potential in the remediation of Cu-contaminated soil in acid rain areas.

  11. Abnormal hepatic copper accumulation of spheroid composed of liver cells from LEC rats in vitro.

    Science.gov (United States)

    Ueno, K; Yoshizawa, M; Satoh, T; Yoneda, S; Ohmichi, M; Yamazaki, M; Mori, Y; Suzuki, K T

    1995-11-01

    The LEC rat is a mutant strain displaying hereditary hepatitis, and shows abnormal accumulation of copper (Cu) similar to that occurring in Wilson's disease. We prepared a multicellular spheroid composed of LEC rat liver cells to investigate the mechanism for abnormal accumulation of Cu. These multicellular spheroids were prepared by detaching the monolayer on the collagen-conjugated thermo-responsive polymer coated culture dish at a temperature below the critical solution temperature and culturing on the non-adhesive substratum. Long-term cultured spheroids of LEC rat liver cells as well as SD rat liver cells were attempted. Non-parenchymal cells obtained by collagenase perfusion from the LEC liver were fewer than those from the SD liver. Cells from the LEC rat, over 11 weeks of age, did not form a cell sheet; however, a mixture of parenchymal cells from LEC rats over aged 11 weeks and non-parenchymal cells from SD rats of any age yielded intact spheroids. We examined the toxicity, the accumulation and distribution of Cu in spheroids. The accumulation of Cu in LEC spheroids was higher than that in SD spheroids. Results suggest that spheroids consisting of LEC liver cells are useful as an alternative model to in vivo tests to investigate the mechanism for abnormal accumulation of Cu in liver.

  12. Ultrafine-Grained Precipitation Hardened Copper Alloys by Swaging or Accumulative Roll Bonding

    Directory of Open Access Journals (Sweden)

    Igor Altenberger

    2015-05-01

    Full Text Available There is an increasing demand in the industry for conductive high strength copper alloys. Traditionally, alloy systems capable of precipitation hardening have been the first choice for electromechanical connector materials. Recently, ultrafine-grained materials have gained enormous attention in the materials science community as well as in first industrial applications (see, for instance, proceedings of NANO SPD conferences. In this study the potential of precipitation hardened ultra-fine grained copper alloys is outlined and discussed. For this purpose, swaging or accumulative roll-bonding is applied to typical precipitation hardened high-strength copper alloys such as Corson alloys. A detailed description of the microstructure is given by means of EBSD, Electron Channeling Imaging (ECCI methods and consequences for mechanical properties (tensile strength as well as fatigue and electrical conductivity are discussed. Finally the role of precipitates for thermal stability is investigated and promising concepts (e.g. tailoring of stacking fault energy for grain size reduction and alloy systems for the future are proposed and discussed. The relation between electrical conductivity and strength is reported.

  13. Penicillamine Increases Free Copper and Enhances Oxidative Stress in the Brain of Toxic Milk Mice

    Science.gov (United States)

    Lin, Xiao-Pu; Zhang, Wei; Li, Fu-Rong; Liang, Xiu-Ling; Li, Xun-Hua

    2012-01-01

    Wilson disease (WD) is characterized by the accumulation of copper arising from a mutation in the ATP7B gene. Penicillamine (PA) makes 10–50% of the patients with neurologic symptoms neurologically worse at the early stage of administration. The aim of this study was to determine how the copper metabolism changes and whether the change impairs the brain of toxic milk (tx) mice, an animal model of WD, during the PA administration. The free copper and protein-bound copper concentrations in the serum, cortex and basal ganglia of tx mice with PA administration for 3 days, 10 days and 14 days, respectively, were investigated. The expression of copper transporters, ATP7A and CTR1,was analyzed by real-time quantitative PCR, immunofluorescence and Western blot. Then SOD, MDA and GSH/GSSG were detected to determine whether the oxidative stress changed correspondingly. The results revealed the elevated free copper concentrations in the serum and brain, and declined protein-bound copper concentrations in the brain of tx mice during PA administration. Meanwhile, transiently increased expression of ATP7A and CTR1 was observed generally in the brain parenchyma by immunofluorescence, real-time quantitative PCR and Western blot. Additionally, ATP7A and CTR1 were observed to locate mainly at Golgi apparatus and cellular membrane respectively. Intense staining of ATP7A in the choroid plexus was found in tx mice on the 3rd and 10th day of PA treatment, but rare staining of ATP7A and CTR1 in the blood-brain barrier (BBB). Decreased GSH/GSSG and increased MDA concentrations were also viewed in the cortex and basal ganglia. Our results suggested the elevated free copper concentrations in the brain might lead to the enhanced oxidative stress during PA administration. The increased free copper in the brain might come from the copper mobilized from brain parenchyma cells but not from the serum according to the ATP7A and CTR1 expression analysis. PMID:22629446

  14. Gama-aminobutyric acid accumulation in Elsholtzia splendens in response to copper toxicity

    Institute of Scientific and Technical Information of China (English)

    YANG Xiao-e; PENG Hong-yun; TIAN Sheng-ke

    2005-01-01

    A solution with different Cu supply levels was cultured to investigate gama-aminobutyric acid (GABA) accumulation in Elsholtzia splendens, a native Chinese Cu-tolerant and accumulating plant species. Increasing Cu from 0.25 to 500 ?mol/L significantly enhanced levels of GABA and histidine (His), but considerably decreased levels of aspartate (Asp) and glutamate (Glu) in the leaves. The leaf Asp level negatively correlated with leaf Cu level, while leaf GABA level positively correlated with leaf Cu level. The leaf Glu level negatively correlated with leaf GABA level in Elsholtzia splendens. The depletion of leaf Glu may be related to the enhanced synthesis ofleafGABA under Cu stress.

  15. Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G. lichenoides (Rhodophyceae)

    Science.gov (United States)

    Huang, Hezhong; Liang, Jiansheng; Wu, Xiaosong; Zhang, Hao; Li, Qianqian; Zhang, Qunying

    2013-07-01

    Heavy metal pollution has become a worldwide problem in aquaculture. We studied copper (Cu2+) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 μg/L in concentration. Compared with G. lemaneiformis, G. lichenoides was more capable in accumulating Cu2+, specifically, more Cu2+ on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast, cell nucleus, mitochondria, and ribosome). In addition, G. lichenoides contained more insoluble polysaccharide in cell wall, which might promote the extracellular Cu2+-binding as an efficient barrier against metal toxicity. Conversely, G. lemaneiformis was more vulnerable than G. lichenoides to Cu2+ toxin for decreases in growth, pigment (chlorophyll a, chlorophyll b, phycobiliprotein, and β-carotene) content, and photosynthetic activity. Moreover, more serious oxidative damages in G. lemaneiformis than in G. lichenoides, in accumulation of reactive oxidative species and malondialdehyde, and in electrolyte leakage, because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities. Therefore, G. lichenoides was less susceptible to Cu2+ stress than G. lemaneiformis.

  16. Agaricus bisporus compost improves the potential of Salix purpurea × viminalis hybrid for copper accumulation.

    Science.gov (United States)

    Magdziak, Z; Mleczek, M; Gąsecka, M; Drzewiecka, K; Kaczmarek, Z; Siwulski, M; Goliński, P

    2016-08-02

    The aim of the study was to determine the ability of spent mushroom compost (SMC) from the production of Agaricus bisporus (A. bisporus) to stimulate the growth and efficiency of copper (Cu) accumulation by Salix purpurea × viminalis hybrid. Roots, shoots and leaves were analysed in terms of total Cu content and selected biometric parameters. Due to the absence of information regarding the physiological response of the studied plant, low molecular weight organic acids (LMWOAs), phenolic compounds and salicylic acid (SA) contents were investigated. The obtained results clearly demonstrate the effectiveness (usefulness) of SMC in promoting the growth and stimulation of Cu accumulation by the studied Salix taxon. The highest Cu content in roots and shoots was found at the 10% SMC addition (507±22 and 380±11 mg kg(-1) DW, respectively), while there was a reduction of the content in leaves and young shoots (109±8 and 124±7 mg kg(-1) DW, respectively). In terms of physiological response, lowered secretion of LMWOAs, biosynthesis of phenolic compounds and SA, as well as accumulation of soluble sugars in Salix leaves was observed with SMC addition. Simultaneously, an elevation of the total phenolic content in leaves of plants cultivated with SMC was observed, considered as antioxidant biomolecules.

  17. Uptake, Distribution and Accumulation of Copper in Two Ecotypes of Elsholtzia

    Institute of Scientific and Technical Information of China (English)

    JIANG Li-Ying; YANG Xiao-E; YE Zheng-Qian; SHI Wei-Yong

    2003-01-01

    Two ecotypes of Elsholtzia, Elsholtzia splendens and E. Argyi, are dominant plants growing on Cu and Pb-Zn smelters, respectively. Samples of the two ecotypes and the corresponding soils from fields of a copper mining area and a Pb-Zn mining area of Zhejiang Province, China, were analyzed to investigate Cu or Zn tolerance of these two ecotypes. Effects of nine Cu levels (0, 5, 10, 20, 40, 80, 160, 240 and 320 mg Cu L-1 as CuSO4@SH20) on growth and uptake, translocation and accumulation of Cu in these two ecotypes were examined in a solution culture experiment. The experimental results showed that dry weights (DW) of shoots and roots were depressed, and growth of E. Splendens was less depressed tha n that of E. Argyi when treated with ≥ 5 mg Cu L-1. Concentrations of Cu in shoots of E. Splendens and E. Argyi exceeded 1 000 mg kg-1 DW at ≥ 40 mg Cu L-x. The maximum Cu accumulated in the shoots of Gu-treated E. Splendens and E. Argyi reached 101 and 142μg plant-1. Furthermore, analysis of plant samples from the fields showed that these two ecotypes can tolerant excess heavy metals and produced high dry matter, and E. Splendens can accumulate 11.7 mg Cu plant-1 grown on the Cu smelter. Therefore, E. Splendens and E. Argyi could be good plants for phytoremediation.

  18. Uptake and accumulation of copper by roots and shoots of maize(Zea may L.)

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    The effects of different concentrations of copper sulfate on rootand shoot growth of maize(Zea mays L.) and the uptake and accumulation of Cu2+ by its roots and shoots were investigated in the present study. The concentrations of opper sulfate (CuSO4.5H2O) used were in the range of 10-5-10-3mol/L. Root growth decreased progressively with increasing concentration of Cu2+ in solution. The seedlings exposed to 10-3 mol/L Cu exhibited substantial growth reduction, yielding only 68% of the root length of the control. The shoot growth of the seedlings grown at 10-5-10-4 mol/L Cu2+ were more or less than the same as the control seedlings. The leaves treated with 10-3 mol/L Cu2+ were obviously inhibited in shoot growth. The fresh and dry weights both in roots and shots decreased progressively with increasing Cu2+ concentration.This fits well with the above mentioned effects of copper sulfate on root growth. Zea mays has considerable ability to remove Cu from solutions and accumulate it. The Cu content in roots of Z. Mays increased with increasing solution concentration of Cu2+. The amount of Cu in roots of plants treated with 10-3, 10-4 and 10-5 mol/L Cu2+ were 10, 8 and 1.5 fold, respectively, greater than that of roots of control plant. However, the plants transported and concentrated only a small amount of Cu in their shoots.

  19. Copper use and accumulation in catfish culture in the Mekong Delta, Vietnam.

    Science.gov (United States)

    Marcussen, Helle; Løjmand, Helle; Dalsgaard, Anders; Hai, Dao M; Holm, Peter E

    2014-01-01

    Aquaculture of Pangasius hypophthalmus (striped catfish) in Vietnam reached 1.1 million tonnes in 2011 and catfish fillets are exported worldwide. The intensive cultures of catfish mainly in earth ponds have made it necessary to apply CuSO4 and other chemicals to control external parasites and other pathogens. However, accumulation of Cu in aquaculture ponds may pose a hazard to growth of fish or to the aquatic environment. The aim of this study was to determine accumulation of Cu in sediment, water and fish in a catfish pond with a history of repeated treatment with CuSO4 in the Mekong Delta, Vietnam. Copper concentrations in pond sediment were in the interval 21.3-45.7 mg kg(-1) dw and did not exceed the Vietnamese values for soil to be used for agricultural production (70 mg kg(-1) dw.). During three samplings the total mean concentration of Cu in pond water (4 μg L(-1)) did not exceed the LC50-value (70 μg L(-1)) for catfish and the mean dissolved concentration of Cu (0.986 μg L(-1)) did not seem to constitute a risk for the stability of the aquatic ecosystem. No significant variation in Cu concentrations between sampling sites in the pond and depth of sediment profile were determined. The accumulation of Cu in catfish was highest in the liver compared to the skin, gills and muscle tissue. With the current practice of removing pond sludge three to four times during a production cycle little if any Cu seems to accumulate in catfish ponds despite repeated anti-parasite treatments with CuSO4. Further studies are needed to assess the eco-toxicity and impact on agricultural production when pond sediment is discharged into aquatic recipients and used as soil fertilizer.

  20. Comparison in copper accumulation and physiological responses of Gracilaria lemaneiformis and G.lichenoides (Rhodophyceae)

    Institute of Scientific and Technical Information of China (English)

    HUANG Hezhong; LIANG Jiansheng; WU Xiaosong; ZHANG Hao; LI Qianqian; ZHANG Qunying

    2013-01-01

    Heavy metal pollution has become a worldwide problem in aquaculture.We studied copper (Cu2+) accumulation and physiological responses of two red algae Gracilaria lemaneiformis and Gracilaria lichenoides from China under Cu2+ exposure of 0-500 tg/L in concentration.Compared with G.lemaneiformis,G.lichenoides was more capable in accumulating Cu2+,specifically,more Cu2+on extracellular side (cell wall) than on intracellular side (cytoplasm) and in cell organelles (especially chloroplast,cell nucleus,mitochondria,and ribosome).In addition,G.lichenoides contained more insoluble polysaccharide in cell wall,which might promote the extracellular Cu2+-binding as an efficient barrier against metal toxicity.Conversely,G.lemaneiformis was more vulnerable than G.lichenoides to Cu2+toxin for decreases in growth,pigment (chlorophyll a,chlorophyll b,phycobiliprotein,and β-carotene)content,and photosynthetic activity.Moreover,more serious oxidative damages in G.lemaneiformis than in G.lichenoides,in accuamultion of reactive oxidative species and malondialdehyde,and in electrolyte leakage,because of lower antioxidant enzyme (superoxide dismutase and glutathione reductase) activities.Therefore,G.lichenoides was less susceptible to Cu2+ stress than G.lemaneiformis.

  1. Copper(II) enhances membrane-bound α-synuclein helix formation.

    Science.gov (United States)

    Lucas, Heather R; Lee, Jennifer C

    2011-03-01

    Interactions of copper and membranes with α-synuclein have been implicated in pathogenic mechanisms of Parkinson's disease, yet work examining both concurrently is scarce. We have examined the effect of copper(ii) on protein/vesicle binding and found that both the copper(ii) affinity and α-helical content are enhanced for the membrane-bound protein.

  2. Copper(II) enhances membrane-bound α-synuclein helix formation

    OpenAIRE

    Lucas, Heather R.; Lee, Jennifer C.

    2011-01-01

    Interactions of copper and membranes with α-synuclein have been implicated in pathogenic mechanisms of Parkinson’s disease, yet work examining both concurrently is scarce. We have examined the effect of copper(II) on protein/vesicle binding and found that both the copper(II) affinity and α-helical content are enhanced for the membrane-bound protein.

  3. Green synthesis of rifampicin-loaded copper nanoparticles with enhanced antimicrobial activity.

    Science.gov (United States)

    Woźniak-Budych, Marta J; Przysiecka, Łucja; Langer, Krzysztof; Peplińska, Barbara; Jarek, Marcin; Wiesner, Maciej; Nowaczyk, Grzegorz; Jurga, Stefan

    2017-03-01

    The antimicrobial properties of copper and rifampicin-loaded copper nanoparticles were investigated using four strains: Staphylococcus aureus, Escherichia coli, Bacillus pumilis and Pseudomonas fluorescens. Spherical-shaped copper nanoparticles were synthesized via green reduction method from the peppermint extract. It was found that adsorption of rifampicin on the copper nanosurface enhances its biological activity and prevents the development of resistance. The interactions between rifampicin-copper nanoparticles and bacteria cells were monitored using atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). It was proven that loaded with rifampicin copper nanoparticles were able to damage the S. aureus cell membrane and facilitate the bacteria biofilm matrix disintegration. Moreover, the DNA decomposition of S. aureus treated with copper and rifampicin-copper nanoparticles was confirmed by agarose gel electrophoresis. The results obtained indicate that adsorption of rifampicin on the copper nanoparticles surface might provide the reduction of antibiotic dosage and prevent its adverse side effects.

  4. Metallothionein expression in chloroplasts enhances mercury accumulation and phytoremediation capability.

    Science.gov (United States)

    Ruiz, Oscar N; Alvarez, Derry; Torres, Cesar; Roman, Laura; Daniell, Henry

    2011-06-01

    Genetic engineering to enhance mercury phytoremediation has been accomplished by expression of the merAB genes that protects the cell by converting Hg[II] into Hg[0] which volatilizes from the cell. A drawback of this approach is that toxic Hg is released back into the environment. A better phytoremediation strategy would be to accumulate mercury inside plants for subsequent retrieval. We report here the development of a transplastomic approach to express the mouse metallothionein gene (mt1) and accumulate mercury in high concentrations within plant cells. Real-time PCR analysis showed that up to 1284 copies of the mt1 gene were found per cell when compared with 1326 copies of the 16S rrn gene, thereby attaining homoplasmy. Past studies in chloroplast transformation used qualitative Southern blots to evaluate indirectly transgene copy number, whereas we used real-time PCR for the first time to establish homoplasmy and estimate transgene copy number and transcript levels. The mt1 transcript levels were very high with 183,000 copies per ng of RNA or 41% the abundance of the 16S rrn transcripts. The transplastomic lines were resistant up to 20 μm mercury and maintained high chlorophyll content and biomass. Although the transgenic plants accumulated high concentrations of mercury in all tissues, leaves accumulated up to 106 ng, indicating active phytoremediation and translocation of mercury. Such accumulation of mercury in plant tissues facilitates proper disposal or recycling. This study reports, for the first time, the use of metallothioneins in plants for mercury phytoremediation. Chloroplast genetic engineering approach is useful to express metal-scavenging proteins for phytoremediation.

  5. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Science.gov (United States)

    Fu, Lei; Chen, Chen; Wang, Bin; Zhou, Xishi; Li, Shuhuan; Guo, Pan; Shen, Zhenguo; Wang, Guiping; Chen, Yahua

    2015-01-01

    Differences in copper (Cu) absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type) and Elsholtzia haichowensis (Cu-enrichment type), were investigated in the present study. The results indicated the following: (1) After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2) An analysis of the endogenous abscisic acid (ABA) variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3) The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4) The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  6. Differences in Copper Absorption and Accumulation between Copper-Exclusion and Copper-Enrichment Plants: A Comparison of Structure and Physiological Responses.

    Directory of Open Access Journals (Sweden)

    Lei Fu

    Full Text Available Differences in copper (Cu absorption and transport, physiological responses and structural characteristics between two types of Cu-resistant plants, Oenothera glazioviana (Cu-exclusion type and Elsholtzia haichowensis (Cu-enrichment type, were investigated in the present study. The results indicated the following: (1 After 50 μM Cu treatment, the Cu ratio in the xylem vessels of E. haichowensis increased by 60%. A Cu adsorption experiment indicated that O. glazioviana exhibited greater resistance to Cu, and Cu absorption and the shoot/root ratio of Cu were significantly lower in O. glazioviana than in E. haichowensis. (2 An analysis of the endogenous abscisic acid (ABA variance and exogenous ABA treatment demonstrated that the ABA levels of both plants did not differ; exogenous ABA treatment clearly reduced Cu accumulation in both plants. (3 The leaf stomatal density of O. glazioviana was significantly less than that of E. haichowensis. Guard cells in E. haichowensis plants were covered with a thick cuticle layer, the epidermal hair was more numerous and longer, and the number of xylem conduits in the root was small. (4 The transpiration rate and the stomatal conductance of O. glazioviana were both significantly lower than those of E. haichowensis, regardless of whether the plants were treated with Cu. Taken together, these results indicate that the differences in the structural characteristics between these two plant species, particularly in the characteristics related to plant transpiration, are important factors that govern whether plants acquire or exclude Cu.

  7. Reduction of fluoranthene of copper and lead accumulation in Triticum aestivum L

    Energy Technology Data Exchange (ETDEWEB)

    Wetzel, A.; Alexander, T.; Brandt, S.; Haas, R.; Werner, D. (Univ. of Marburg (Germany))

    1994-12-01

    Fluoranthene is one of the most important representatives of the polycyclic aromatic hydrocarbons. Coaltar production alone yields about 30000 t of fluoranthene per year. In spite of its abundance, however, very little is known about its effects on the environment. Groenewegen and Stolp investigated the half-life of this substance in soil and found values between 44 and 182 days, depending on the soil matrix. PAHs may migrate into soil organic matter, representing less accessible sites within the soil matrix. Such sorbed PAHs are suggested to be non-bioavailable and thus non-biodegradable. Fluoranthene has long been classified as non-carcinogenic and largely non-hazardous. The oral toxicity rating is indeed low, being only 2000 mg [center dot] kg[sup [minus]1] for rats and mice (LD[sub 50]), but there are also reports of mutagenic and toxic effects of fluoranthene on animals and plants. Fluoranthene has been reported to be synthesized by spermatophytes. However, accumulation of fluoranthene and other PAHs in plants is generally attributed to contamination by airborne particulate matter. Lettuce, soya, rye and tobacco plants grown in air-filtered chambers failed to synthesize PAHs, but accumulation of such substances was observed in a normal greenhouse. Transfer of fluoranthene from polluted soil via roots to shoots is probably limited due to the high n-octanol/water partition coefficient log P[sub OW] of fluoranthene: 5.33. However, there seems to be a stimulation of PAH uptake by mosses and spermatophytes in heavy metal-stressed soils. The aim of the present study was to determine toxic effects of fluoranthene on wheat and whether there were any interactions between toxicity and uptake of fluoranthene, lead and copper in hydroponic culture systems. 21 refs., 4 tabs.

  8. Copper and zinc uptake by rice and accumulation in soil amended with municipal solid waste compost

    Science.gov (United States)

    Bhattacharyya, P.; Chakraborty, A.; Chakrabarti, K.; Tripathy, S.; Powell, M. A.

    2006-04-01

    Effect of addition of municipal solid waste compost (MSWC) on two metals viz. copper (Cu) and zinc (Zn) contents of submerged rice paddies were studied. Experiments were conducted during the three consecutive wet seasons from 1997 to 1999 on rice grown under submergence, at the Experimental Farm of Calcutta University, India. A sequential extraction method was used to determine the metal (Cu and Zn) fractions in MSWC and cow dung manure (CDM). Both metals were significantly bound to the organic matter and Fe and Mn oxides in MSWC and CDM. Metal content in rice straw was higher than in rice grain. Metal bound with Fe and Mn oxides in MSWC and CDM best correlated with straw and grain metal followed by exchangeable and water soluble fractions. Carbonate, organic matter bound and residual fractions in MSWC and CDM did not significantly correlate with rice straw and grain metal. The MSWC would be a valuable resource for agriculture if it can be used safely, but long-term field experiments with MSWC are needed to assess by regular monitoring of the metal loads and accumulation in soil and plants.

  9. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola.

    Science.gov (United States)

    Li, Zhu; Wu, Longhua; Hu, Pengjie; Luo, Yongming; Christie, Peter

    2013-10-15

    Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5-50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola. Copyright © 2013 Elsevier B.V. All rights reserved.

  10. Copper Accumulation, Availability and Adsorption Capacity in Sandy Soils of Vineyards with Different Cultivation Duration

    Science.gov (United States)

    Mallmann, F. J. K.; Miotto, A.; Bender, M. A.; Gubiani, E.; Rheinheimer, D. D. S.; Kaminski, J.; Ceretta, C. A.; Šimůnek, J.

    2015-12-01

    Bordeaux mixture is a copper-based (Cu) fungicide and bactericide applied in vineyards to control plant diseases. Since it is applied several times per year, it accumulates in large quantities on plants and in soil. This study evaluates the Cu accumulation in, and desorption kinetics and adsorption capability of a sandy Ultisol in a natural field and in 3 vineyards for 5 (V1), 11 (V2), and 31 (V3) years in South of Brazil. Soil samples were collected in 8 depths (0-60 cm) of all four soil profiles, which all displayed similar soil properties. The following soil properties were measured: pH, organic matter (OM), soil bulk density, Cu total concentration, and Cu desorption and adsorption curves. A two first-order reactions model and the Langmuir isotherm were fitted to the desorption and adsorption curves, respectively. An increase in the total mass of Cu in the vineyards followed a linear regression curve, with an average annual increase of 7.15 kg ha-1. Cu accumulated down to a depth of 5, 20, and 30 cm in V1, V2 and V3, respectively, with the highest Cu content reaching 138.4 mg kg-1 in the 0-5 cm soil layer of V3. Cu desorption parameters showed a high correlation with its total concentration. Approximately 57 and 19% of total Cu were immediately and slowly available, respectively, indicating a high potential for plant absorption and/or downward movement. Cu concentrations extracted by EDTA from soil layers not affected by anthropogenic Cu inputs were very low. The maximum Cu adsorption capacity of the 0-5 and 5-10 cm soil layers increased with the vineyard age, reaching concentrations higher than 900 mg kg-1. This increase was highly related to OM and pH, which both increased with cultivation duration. Despite of low clay content of these soils, there is low risk of groundwater Cu contamination for actual conditions. However, high Cu concentrations in the surface layer of the long-term vineyards could cause toxicity problems for this and for companion crops.

  11. Marginal Copper Deficiency Increases Liver Neutrophil Accumulation After Ischemia/Reperfusion in Rats

    Science.gov (United States)

    Copper deficiency can lead to an augmented inflammatory response through effects on both neutrophils and the microvascular endothelium. In the present study, we evaluated the effect of marginal copper deficiency on the inflammatory injury response to hepatic ischemia/reperfusion injury. Male weanlin...

  12. Enhanced Quantum Efficiency From Hybrid Cesium Halide/Copper Photocathode

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Lingmei; Joly, Alan G.; Droubay, Timothy C.; Gong, Yu; Hess, Wayne P.

    2014-04-28

    The quantum efficiency of Cu is found to increase dramatically when coated by a CsI film and then irradiated by a UV laser. Over three orders of magnitude quantum efficiency enhancement at 266 nm is observed in CsI/Cu(100), indicating potential application in future photocathode devices. Upon laser irradiation, a large work function reduction to a value less than 2 eV is also observed, significantly greater than for similarly treated CsBr/Cu(100). The initial QE enhancement, prior to laser irradiation, is attributed to interface interaction, surface cleanliness and the intrinsic properties of the Cs halide film. Further QE enhancement following activation is attributed to formation of inter-band states and Cs metal accumulation at the interface induced by laser irradiation.

  13. Copper changes the yield and cadmium/zinc accumulation and cellular distribution in the cadmium/zinc hyperaccumulator Sedum plumbizincicola

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhu [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); University of the Chinese Academy of Sciences, Beijing 100049 (China); Wu, Longhua, E-mail: lhwu@issas.ac.cn [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Hu, Pengjie [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Luo, Yongming [Key Laboratory of Soil Environment and Pollution Remediation, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008 (China); Yantai Institute of Coastal Zone Research, Yantai 264003 (China); Christie, Peter [Agri-Environment Branch, Agri-Food and Biosciences Institute, Newforge Lane, Belfast BT9 5PX (United Kingdom)

    2013-10-15

    Highlights: • Low Cu has no significant effect on Sedum plumbizincicola plant growth and Cd and Zn uptake. • Plant held Cu in unactive areas and insoluble forms as de-toxification mechanisms. • Influence of Cu on Zn and Cd uptake and translocation were different. • Cu accumulation in leaf veins may restrain Cd/Zn unloading to the leaves -- Abstract: Non-accumulated metals in mixed metal contaminated soils may affect hyperaccumulator growth and metal accumulation and thus remediation efficiency. Two hydroponics experiments were conducted to investigate the effects of copper (Cu) on cadmium (Cd) and zinc (Zn) accumulation by the Cd/Zn hyperaccumulator Sedum plumbizincicola, Cu toxicity and plant detoxification using chemical sequential extraction of metals, sub-cellular separation, micro synchrotron radiation based X-ray fluorescence, and transmission electron microscopy. Compared with the control (0.31 μM Cu), 5–50 μM Cu had no significant effect on Cd/Zn accumulation, but Cu at 200 μM induced root cell plasmolysis and disordered chloroplast structure. The plants held Cu in the roots and cell walls and complexed Cu in insoluble forms as their main detoxification mechanisms. Exposure to 200 μM Cu for 4 days inhibited plant Cd uptake and translocation but did not affect Zn concentrations in roots and stems. Moreover, unloading of Cd and Zn from stem to leaf was restrained compared to control plants, perhaps due to Cu accumulation in leaf veins. Copper may thus interfere with root Cd uptake and restrain Cd/Zn unloading to the leaves. Further investigation of how Cu affects plant metal uptake may help elucidate the Cd/Zn hyper-accumulating mechanisms of S. plumbizincicola.

  14. Sublethal effects of copper sulphate compared to copper nanoparticles in rainbow trout (Oncorhynchus mykiss) at low pH: physiology and metal accumulation.

    Science.gov (United States)

    Al-Bairuty, Genan A; Boyle, David; Henry, Theodore B; Handy, Richard D

    2016-05-01

    A few studies have investigated the interaction between copper toxicity and water pH in fishes, but little is known about the effects of acidic pH on the toxicity of copper nanoparticles (Cu-NPs). This study aimed to describe the sub-lethal toxic effects of Cu-NPs compared to CuSO4 at neutral and acidic water pH values in juvenile rainbow trout. Fish were exposed in triplicate (3 tanks/treatment) to control (no added Cu), or 20μgl(-1) of either Cu as CuSO4 or Cu-NPs, at pH 7 and 5 in a semi-static aqueous exposure regime for up to 7 days. Acidification of the water altered the mean primary particle size (at pH 7, 60±2nm and pH 5, 55±1nm) and dialysis experiments to measure dissolution showed an increased release of dissolved Cu from Cu-NPs at pH 5 compared to pH 7. Copper accumulation was observed in the gills of trout exposed to CuSO4 and Cu-NPs at pH 7 and 5, with a greater accumulation from the CuSO4 treatment than Cu-NPs at each pH. The liver also showed Cu accumulation with both Cu treatments at pH 7 only, whereas, the spleen and kidney did not show measurable accumulation of Cu at any of the water pH values. Exposure to acid water caused changes in the ionoregulatory physiology of control fish and also altered the observed effects of Cu exposure; at pH 5, branchial Na(+)/K(+)-ATPase activity was greater than at pH 7 and the inhibition of Na(+)/K(+)-ATPase activity caused by exposure to CuSO4 at pH 7 was also not observed. There were some changes in haematology and depletion of plasma Na(+) at pH 7 and 5 due to Cu exposure, but there were few material-type or pH effects. Overall, the data show that the accumulation of Cu is greater from CuSO4 than Cu-NPs; however, understanding of the effects of low pH on bioavailability of CuSO4 may not be directly transferred to Cu-NPs without further consideration of the physico-chemical behaviour of Cu-NPs in acid water.

  15. Copper and copper proteins in Parkinson's disease.

    Science.gov (United States)

    Montes, Sergio; Rivera-Mancia, Susana; Diaz-Ruiz, Araceli; Tristan-Lopez, Luis; Rios, Camilo

    2014-01-01

    Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson's disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson's disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson's disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson's disease and that a mutation in ATP7B could be associated with Parkinson's disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  16. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager

    2015-01-01

    Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years was cons......Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years......-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide...

  17. Diminution of toxic copper accumulation in toxic milk mice modeling Wilson disease by embryonic hepatocyte intrasplenic transplantation

    Institute of Scientific and Technical Information of China (English)

    Zhu Shi; Xiu-Ling Liang; Bing-Xun Lu; Su-Yue Pan; Xi Chen; Qi-Qiang Tang; Ying Wang; Fan Huang

    2005-01-01

    AIM: To observe the therapeutic effect of intrasplenic transplantation with embryonic hepatocytes on amelioration of hereditary copper accumulation in toxic milk (TX) mouse modeling Wilson disease. METHODS: Donor hepatocytes were harvested from 14-d fetal liver of a pregnant homogeneous DL mouse. These cells were successively cultured, labeled with fluorescein dye Hoechst 33342 for 24 h, and sequentially infused into the spleen parenchyma of the recipient TX mice. No host immunosuppression measures were taken. Two and four weeks after transplantation, the recipients were killed for routine histologic investigation and immunohistochemistry study up to 4 wk after transplantation. The serum copper and ceruloplasmin concentrations of the recipient mice were determined by graphite furnace atomic absorption spectroscopy.RESULTS: In the following 2nd and 4th wk after transplantation, the donor hepatocytes could be visualized in the livers of 47.3% recipients. The serum ceruloplasmin and copper concentrations increased by 1.6-fold after 2 wk and 2.0-fold times after 4 wk respectively, which ultimately rose from about 30% of the normal level to nearly 60%(P<0.01). The hepatic copper concentration decreased 7.2%, 4 wk after transplantation. Pathologic examination showed that there were many actively proliferative hepatocyte precursor cells with specific embryonic hepatocyte marker AFP migrated into hepatic sinusoidsof the recipients. A large number of cells carrying hepatocytes marker and albumin were observed in the recipient spleen tissues.CONCLUSION: Embryonic hepatocytes are capable of differentiating into mature hepatocytes in vivo. After transplantation, the hereditary abnormalities of copper metabolism in TX mice could be corrected partially by intrasplenic transplantation of homogeneous embryonic hepatocytes.

  18. Hydrophilic Cnt-Sintered Copper Composite Wick for Enhanced Cooling

    Science.gov (United States)

    Powell, Glen A.; Bulusu, Anuradha; Weibel, Justin A.; Kim, Sungwon S.; Garimella, Suresh V.; Fisher, Timothy S.

    The need to increase the performance and functionality of heat transfer devices in diverse areas ranging from power electronics and energy conversion to biotechnology and manufacturing has led to significant thermal transport challenges. Heat pipes have emerged as an attractive alternative for passive and compact cooling solutions due to the enhanced performance realized via liquid-vapor phase change. The choice of an appropriate wick structure is critical to the performance of a heat pipe as the capillary and boiling limits on performance are directly related to the wick structure. An ideal wick structure offers good capillary pumping and nucleate boiling characteristics while maintaining low thermal resistance. We present a heat pipe wick structure that incorporates nano and microscale elements to improve wicking and thin film evaporation. The sintered copper-carbon-nanotube composite wick structure is tested for thermal performance, and successfully supported high heat fluxes of the order of 500 W/cm2 with low thermal resistances ranging between 0.2-0.4°C/W.

  19. Comparison of defect cluster accumulation and pattern formation in irradiated copper and nickel

    Energy Technology Data Exchange (ETDEWEB)

    Zinkle, S.J.; Snead, L.L. [Oak Ridge National Lab., TN (United States); Edwards, D.J. [Pacific Northwest Lab., Richland, WA (United States)] [and others

    1995-04-01

    The objective of this study is to compare the contrasting behavior of defect cluster formation in neutron-irradiated copper and nickel specimens. Transmission electron microscopy was used to examine the density and spatial distribution of defect clusters produced in copper and nickel as the result of fission neutron irradiation to damage levels of 0.01 to 0.25 displacements per atom (dpa) at irradiation temperature between 50 and 230{degrees}C. A comparison with published results in the literature indicates that defect cluster wall formation occurs in nickel irradiated at 0.2 to 0.4 T{sub M} in a wide variety of irradiation spectra. Defect cluster wall formation apparently only occurs in copper during low temperature irradiation with electrons and light ions. These results are discussed in terms of the thermal spike model for energetic displacement cascades.

  20. Electrokinetic removal of chromium and copper from contaminated soils by lactic acid enhancement in the catholyte

    Institute of Scientific and Technical Information of China (English)

    ZHOU Dong-mei; Alshawabkeh Akram N; DENG Chang-fen; CANG Long; SI You-bin

    2004-01-01

    The electrokinetic removal of chromium and copper from contaminated soils by adding lactic acid in cathode chamber as an enhancing reagent was evaluated. Two sets of duplicate experiments with chromium contaminated kaolinite and with a silty soil sampled from a superfund site in California of USA and polluted by Cr and Cu, were carried out in a constant current mode. Changes of soil water content and soil pH before and after the electrokinetic experiments, and variations of voltage drop and electroosmosis flow during the treatments were examined. The results indicated that Cr, spiked as Cr(Ⅵ) in the kaolinite, was accumulated mainly in the anode chamber, and some of Cr and metal hydroxides precipitated in the soil sections in contact with the cathode, which significantly increased electrical energy consumption. Treatment of the soil collected from the site showed accumulation of large amounts of Cr and Cu in the anode chamber while none was detected in the cathode one. The results suggested that the two metals either complexed with the injected lactic acid at the cathode or existed as negatively charged complex, and electromigrated toward the anode under a voltage gradient.

  1. Evaluation of a commercially available molybdate formulation and zinc oxide boluses in preventing hepatic copper accumulation and thus enzootic icterus in sheep

    Directory of Open Access Journals (Sweden)

    C.J. Botha

    2001-07-01

    Full Text Available The efficacy of a molybdate formulation and a zinc oxide bolus as prophylactic agents for enzootic icterus was evaluated in sheep. Before copper loading, liver biopsies were performed on 12 male, 6-month-old, Mutton Merino sheep to determine hepatic copper (Cu and zinc (Zn concentrations. The animals were restrictively randomised according to liver copper concentrations to 3 treatment groups (n = 4 to achieve similar mean liver copper concentrations per group. All sheep received 4 m /kg of a 0.5 %aqueous solution of CuSO4·5H2O intraruminally 7 days per week for 10 weeks. On Day 0 the sheep in the Mo-group were injected subcutaneously with 42 mg molybdenum (Mo contained in a commercial molybdate formulation. The animals in the Zn-group each received a zinc oxide bolus, containing 43 g zinc oxide, via a rumen cannula. Treatment was repeated on Day 42. Four animals served as untreated controls. Urinary copper excretion, plasma copper concentration, haematocrit and glutamate dehydrogenase (GLDH activity were determined throughout the trial. The animals were sacrificed after 10 weeks and liver samples were submitted for histopathological examination. Liver and kidney copper and zinc concentrations were determined. Neither the molybdate treatment nor the zinc oxide boluses prevented hepatic copper accumulation. The urinary copper excretion, plasma copper concentration, haematocrit and GLDH activity were not significantly different (P > 0.05 from the controls.

  2. Strengthening Mechanisms and Electrochemical Behavior of Ultrafine-Grained Commercial Pure Copper Fabricated by Accumulative Roll Bonding

    Science.gov (United States)

    Imantalab, O.; Fattah-Alhosseini, A.; Mazaheri, Y.; Keshavarz, M. K.

    2016-07-01

    In this study, the four-cycle accumulative roll bonding (ARB) process at room temperature was successfully used for grain refining in commercial pure copper. Atomic force microscopy (AFM) images revealed that the average grain size reduced from about 26 µm in the unprocessed material to about 180 nm after four cycles of ARB. Also, transmission electron microscopy image indicated that the average grain size reached to 200 nm after four cycles. The yield strength of the ultrafine-grained pure copper after fourth cycle (360 MPa) was about 400 pct higher than that of the annealed unprocessed sample (70 MPa). The contribution of dislocations in strengthening of the pure copper decreased from ~30 to ~3 pct whit increasing the number of ARB cycles from 1 to 4. Scanning electron microscopy micrographs of fractured surfaces of the tensile test specimens revealed that ductile fracture of annealed sample with deep equiaxed dimples replaced by shear ductile rupture with shallow and small elongated dimples in ARB-processed samples. Moreover, electrochemical impedance spectroscopy and Mott-Schottky analysis showed that the electrochemical behavior improved by increasing the number of ARB cycle.

  3. Spin Injection and Spin Accumulation in Permalloy–Copper Mesoscopic Spin Valves

    NARCIS (Netherlands)

    Jedema, F.J.; Filip, A.T.; Wees, B.J. van

    2002-01-01

    We study the electrical injection and detection of spin currents in a lateral spin valve device, using permalloy (Py) as ferromagnetic injecting and detecting electrodes and copper (Cu) as nonmagnetic metal. Our multiterminal geometry allows us to experimentally distinguish different magnetoresistan

  4. COMMD1-deficient dogs accumulate copper in hepatocytes and provide a good model for chronic hepatitis and fibrosis.

    Directory of Open Access Journals (Sweden)

    Robert P Favier

    Full Text Available New therapeutic concepts developed in rodent models should ideally be evaluated in large animal models prior to human clinical application. COMMD1-deficiency in dogs leads to hepatic copper accumulation and chronic hepatitis representing a Wilson's disease like phenotype. Detailed understanding of the pathogenesis and time course of this animal model is required to test its feasibility as a large animal model for chronic hepatitis. In addition to mouse models, true longitudinal studies are possible due to the size of these dogs permitting detailed analysis of the sequence of events from initial insult to final cirrhosis. Therefore, liver biopsies were taken each half year from five new born COMMD1-deficient dogs over a period of 42 months. Biopsies were used for H&E, reticulin, and rubeanic acid (copper staining. Immunohistochemistry was performed on hepatic stellate cell (HSC activation marker (alpha-smooth muscle actin, α-SMA, proliferation (Ki67, apoptosis (caspase-3, and bile duct and liver progenitor cell (LPC markers keratin (K 19 and 7. Quantitative RT-PCR and Western Blots were performed on gene products involved in the regenerative and fibrotic pathways. Maximum copper accumulation was reached at 12 months of age, which coincided with the first signs of hepatitis. HSCs were activated (α-SMA from 18 months onwards, with increasing reticulin deposition and hepatocytic proliferation in later stages. Hepatitis and caspase-3 activity (first noticed at 18 months increased over time. Both HGF and TGF-β1 gene expression peaked at 24 months, and thereafter decreased gradually. Both STAT3 and c-MET showed an increased time-dependent activation. Smad2/3 phosphorylation, indicative for fibrogenesis, was present at all time-points. COMMD1-deficient dogs develop chronic liver disease and cirrhosis comparable to human chronic hepatitis, although at much higher pace. Therefore they represent a genetically-defined large animal model to test clinical

  5. Accumulation of cadmium and copper by female Oxya chinensis(Orthopera: Acridoidea) in soil-plant-insect system

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    One purpose of this research is to present accumulation of cadmium (Cd) and copper (Cu) by female Oxya chinensis (Orthopera: Acridoidea) in a simulated soil-plant-insect ecosystem treated with Cd. Fourth-instar nymphs of O. chinensis had been fed on wheat (Triticum aestivum) seedlings contaminated with Cd and Cu for one month. In the ecosystem, the Cd concentration in wheat seedlings rose greatly with the increasing of Cd in the soil, but the Cu concentration in wheat seedlings was not found elevated. There was a highly significant difference(P<0.05) in Cd concentrations of wheat seedlings and not any significant difference(P>0.05) in Cu concentrations of wheat seedlings. The Cd and Cu concentration in different body part-head, thorax, abdomen, and hind femur, varied under different Cd concentrations in soil. There were significant differences (P<0.05) in the four parts of Cd and Cu accumulations with all treatments. The order of Cd accumulation was thorax >abdomen >head >hind femur and the Cu was abdomen > thorax >head > hind femur. The results indicated that Cd and Cu were accumulated from the soil to grasshoppers through the plant; that is to say, Cd and Cu in environment could be transported to animal or human via food chain.

  6. Glutathione transferase from Trichoderma virens enhances cadmium tolerance without enhancing its accumulation in transgenic Nicotiana tabacum.

    Directory of Open Access Journals (Sweden)

    Prachy Dixit

    Full Text Available BACKGROUND: Cadmium (Cd is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. RESULTS: Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. CONCLUSION: The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for

  7. Apatite accumulation enhances the mechanical property of anammox granules

    NARCIS (Netherlands)

    Lin, Y. M.; Lotti, T.; Sharma, P. K.; van Loosdrecht, M. C. M.

    2013-01-01

    The strength of granular sludge is essential for the mechanical stability of the granules. Inorganic precipitants form a major factor influencing the strength of the granules. To check the possibility of apatite accumulation in anammox granules, and study its contribution to the mechanical strength

  8. Enhanced Olefin Cross Metathesis Reactions: The Copper Iodide Effect

    Science.gov (United States)

    Voigtritter, Karl; Ghorai, Subir

    2011-01-01

    Copper iodide has been shown to be an effective co-catalyst for the olefin cross metathesis reaction. In particular, it has both a catalyst stabilizing effect due to iodide ion, as well as copper(I)-based phosphine-scavenging properties that apply to use of the Grubbs-2 catalyst. A variety of Michael acceptors and olefinic partners can be cross-coupled under mild conditions in refluxing diethyl ether that avoid chlorinated solvents. This effect has also been applied to chemistry in water at room temperature using the new surfactant TPGS-750-M. PMID:21528868

  9. Monoclonal antibodies against accumulation-associated protein affect EPS biosynthesis and enhance bacterial accumulation of Staphylococcus epidermidis.

    Directory of Open Access Journals (Sweden)

    Jian Hu

    Full Text Available Because there is no effective antibiotic to eradicate Staphylococcus epidermidis biofilm infections that lead to the failure of medical device implantations, the development of anti-biofilm vaccines is necessary. Biofilm formation by S. epidermidis requires accumulation-associated protein (Aap that contains sequence repeats known as G5 domains, which are responsible for the Zn(2+-dependent dimerization of Aap to mediate intercellular adhesion. Antibodies against Aap have been reported to inhibit biofilm accumulation. In the present study, three monoclonal antibodies (MAbs against the Aap C-terminal single B-repeat construct followed by the 79-aa half repeat (AapBrpt1.5 were generated. MAb(18B6 inhibited biofilm formation by S. epidermidis RP62A to 60% of the maximum, while MAb(25C11 and MAb(20B9 enhanced biofilm accumulation. All three MAbs aggregated the planktonic bacteria to form visible cell clusters. Epitope mapping revealed that the epitope of MAb(18B6, which recognizes an identical area within AapBrpt constructs from S. epidermidis RP62A, was not shared by MAb(25C11 and MAb(20B9. Furthermore, all three MAbs were found to affect both Aap expression and extracellular polymeric substance (EPS, including extracellular DNA and PIA biosynthesis in S. epidermidis and enhance the cell accumulation. These findings contribute to a better understanding of staphylococcal biofilm formation and will help to develop epitope-peptide vaccines against staphylococcal infections.

  10. Distribution and accumulation of mercury and copper in mangrove sediments in Shenzhen, the world's most rapid urbanized city.

    Science.gov (United States)

    Li, Ruili; Xu, Hualin; Chai, Minwei; Qiu, Guo Yu

    2016-02-01

    To investigate the influence of mangrove forest on heavy metal accumulation and storage in intertidal sediments, core sediments from natural mangrove, restored mangrove, and adjacent mud flat spanning the intertidal zone along the south coastline of the most heavily urbanized Deep bay, Guangdong province, China were analyzed. The average concentrations of mercury (Hg) in surface sediments of natural mangrove and restored mangrove were 172 and 151 ng g(-1), whereas those of copper (Cu) were 75 and 50 μg g(-1), respectively. Compared to those from other typical mangrove wetlands of the world, the metal levels in Shenzhen were at median to high levels, which is consistent with the fact that Shenzhen is in high exploitation and its mangrove suffer intensive impact from human activities. Hg and Cu concentration profiles indicated a higher metal accumulation in surface layers of sediments, in agreement with enrichment of organic matter contents. Maximum concentration, enrichment factors, and excess (background-deducted) concentration inventories of metals (Hg and Cu) were substantially different between environments, decreasing from natural mangrove sediments to restored mangrove sediments to mud flat. Furthermore, metal inputs to Futian mangrove decreased in the order natural mangrove > restored mangrove > mud flat, indicating that mangrove facilitated the accumulation and storage of Hg and Cu in sediment layers.

  11. Particle size effects in the thermal conductivity enhancement of copper-based nanofluids

    Directory of Open Access Journals (Sweden)

    Sahin Huseyin

    2011-01-01

    Full Text Available Abstract We present an analysis of the dispersion characteristics and thermal conductivity performance of copper-based nanofluids. The copper nanoparticles were prepared using a chemical reduction methodology in the presence of a stabilizing surfactant, oleic acid or cetyl trimethylammonium bromide (CTAB. Nanofluids were prepared using water as the base fluid with copper nanoparticle concentrations of 0.55 and 1.0 vol.%. A dispersing agent, sodium dodecylbenzene sulfonate (SDBS, and subsequent ultrasonication was used to ensure homogenous dispersion of the copper nanopowders in water. Particle size distribution of the copper nanoparticles in the base fluid was determined by dynamic light scattering. We found that the 0.55 vol.% Cu nanofluids exhibited excellent dispersion in the presence of SDBS. In addition, a dynamic thermal conductivity setup was developed and used to measure the thermal conductivity performance of the nanofluids. The 0.55 vol.% Cu nanofluids exhibited a thermal conductivity enhancement of approximately 22%. In the case of the nanofluids prepared from the powders synthesized in the presence of CTAB, the enhancement was approximately 48% over the base fluid for the 1.0 vol.% Cu nanofluids, which is higher than the enhancement values found in the literature. These results can be directly related to the particle/agglomerate size of the copper nanoparticles in water, as determined from dynamic light scattering.

  12. Particle size effects in the thermal conductivity enhancement of copper-based nanofluids.

    Science.gov (United States)

    Saterlie, Michael; Sahin, Huseyin; Kavlicoglu, Barkan; Liu, Yanming; Graeve, Olivia

    2011-03-14

    We present an analysis of the dispersion characteristics and thermal conductivity performance of copper-based nanofluids. The copper nanoparticles were prepared using a chemical reduction methodology in the presence of a stabilizing surfactant, oleic acid or cetyl trimethylammonium bromide (CTAB). Nanofluids were prepared using water as the base fluid with copper nanoparticle concentrations of 0.55 and 1.0 vol.%. A dispersing agent, sodium dodecylbenzene sulfonate (SDBS), and subsequent ultrasonication was used to ensure homogenous dispersion of the copper nanopowders in water. Particle size distribution of the copper nanoparticles in the base fluid was determined by dynamic light scattering. We found that the 0.55 vol.% Cu nanofluids exhibited excellent dispersion in the presence of SDBS. In addition, a dynamic thermal conductivity setup was developed and used to measure the thermal conductivity performance of the nanofluids. The 0.55 vol.% Cu nanofluids exhibited a thermal conductivity enhancement of approximately 22%. In the case of the nanofluids prepared from the powders synthesized in the presence of CTAB, the enhancement was approximately 48% over the base fluid for the 1.0 vol.% Cu nanofluids, which is higher than the enhancement values found in the literature. These results can be directly related to the particle/agglomerate size of the copper nanoparticles in water, as determined from dynamic light scattering.

  13. Enhanced tolerance and accumulation of heavy metal ions by engineered Escherichia coli expressing Pyrus calleryana phytochelatin synthase.

    Science.gov (United States)

    Li, Hui; Cong, Yu; Lin, Jing; Chang, Youhong

    2015-03-01

    Contamination by heavy metals is a major environmental problem worldwide and microbial bioremediation is an efficient method for removing this type of pollution. The plant enzymephytochelatin synthase (PCS, also known as glutathione g-glutamylcysteinyltransferase, EC2.3.2.15) involved in the synthesis of phytochelatins (PCs), which are metal-binding cysteine-rich peptides, has a major role in the detoxification of heavy metals in plants. Expression of the PcPCS1 gene from the bean pear (Pyrus calleryana Dcne.) was induced after cadmium and copper treatments. However, functional analysis of this gene in vivo has not been reported. And it is or not suitable for bioremediation also needs to be assessed. In this study, we found Escherichia coli with over-expressed PcPCS1 had enhanced tolerance to cadmium, copper, sodium, and mercury. E. colicells transformed with pPcPCS1 was found to survive in solid M9 medium containing 2.0 mM Cd(2+), 4.0 mM Cu(2+). 4.5% (w/v) Na+, or 200 μ MHg(2+). Moreover, the growth curve showed 1.5 mM Cd(2+), 2.5 mM Cu(2+), 3.5% (w/v) Naþ, and 100 μ MHg(2+) had no effect on the growth of the E. coli cells transformed with pPcPCS1. Also, we found the contents of PCs and the accumulation of cadmium,copper, sodium, and mercury ions were enhanced in the recombinant E. coli strain Rosetta(TM) (DE3).These results suggested the PcPCS1 gene might be a candidate for heavy metal bioremediation via recombinant bacteria.

  14. The Role of the N-terminus of Mammalian Copper Transporter 1 in the Cellular Accumulation of Cisplatin

    Science.gov (United States)

    Larson, Christopher A.; Adams, Preston L.; Jandial, Danielle D.; Blair, Brian G.; Safaei, Roohangiz; Howell, Stephen B.

    2010-01-01

    The mammalian Copper Transporter 1 (CTR1) is responsible for the uptake of copper (Cu) from the extracellular space, and has been shown to play a major role in the initial accumulation of platinum-based drugs. In this study we re-expressed wild type and structural variants of hCTR1 in mouse embryo fibroblasts in which both alleles of mCTR1 had been knocked out (CTR1−/−) to examine the role of the N-terminal extracellular domain of hCTR1 in the accumulation of cisplatin (cDDP). Deletion of either the first 45 amino acids or just the 40MXXM45 motif in the N-terminal domain did not alter subcellular distribution or the amount of protein in the plasma membrane but it eliminated the ability of hCTR1 to mediate the uptake of Cu. In contrast it only partially reduced cDDP transport capacity. Neither of these structural changes prevented cDDP from triggering the rapid degradation of hCTR1. However, they did alter the potency of the cDDP that achieved cell entry, possibly reflecting the fact that hCTR1 may mediate the transport of cDDP both through the pore it forms in the plasma membrane and via endocytosis. We conclude that cDDP interacts with hCTR1 both at 40MXXM45 and at sites outside the N-terminal domain that produce the conformational changes that trigger degradation. PMID:20451502

  15. Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change

    Science.gov (United States)

    Kirwan, M.L.; Blum, L.K.

    2011-01-01

    Coastal wetlands are responsible for about half of all carbon burial in oceans, and their persistence as a valuable ecosystem depends largely on the ability to accumulate organic material at rates equivalent to relative sea level rise. Recent work suggests that elevated CO2 and temperature warming will increase organic matter productivity and the ability of marshes to survive sea level rise. However, we find that organic decomposition rates increase by about 12% per degree of warming. Our measured temperature sensitivity is similar to studies from terrestrial systems, twice as high as the response of salt marsh productivity to temperature warming, and roughly equivalent to the productivity response associated with elevated CO2 in C3 marsh plants. Therefore, enhanced CO2 and warmer temperatures may actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Simple projections indicate that elevated temperatures will increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

  16. A correlative study of hydrogen peroxide accumulation after mercury or copper treatment observed in root nodules of Medicago truncatula under light, confocal and electron microscopy.

    Science.gov (United States)

    Górska-Czekaj, Magdalena; Borucki, Wojciech

    2013-01-01

    Heavy metal stress affects both, nodulation and nitrogen fixation of legumes. Mercury triggers disturbances in cellular structure and metabolism but its influence on ROS generation is poorly understood. Copper is redox active metal which in opposition to mercury is an essential micronutrient for plants. Excess of copper is cytotoxic, as it participates in ROS generation via Fenton-type reaction. The present work describes changes in hydrogen peroxide (H₂O₂) accumulation in response to monthly stress caused by mercury (6 mg/L HgCl₂) or copper (60 mg/L CuCl₂) in root nodules. H₂O₂ accumulation viewed with a light microscopy was detected by the use of diaminobenzidine (DAB). 2',7'-Dichlorofluorescein diacetate (H2DCF-DA) was used as a probe for the intracellular localization of H₂O₂ with a confocal laser scanning system. H₂O₂ detection under transmission electron microscopy was performed by the use of cerium method. Histochemical localization and light and confocal microscopy investigations revealed that under Hg or Cu treatments distinct amount of H₂O₂ accumulated mainly in the interzone and nitrogen-fixing zone. Under normal conditions H₂O₂ accumulated predominantly in the interzone. Electron microscopy observations showed H₂O₂ accumulation under Hg or Cu- treatments around peribacteroid membranes of mature symbiosomes located within nitrogen-fixing zone. It should be underlined that under normal conditions H₂O₂ was not detected at the peribacteroid membranes. The main result of our observations is increased accumulation of H₂O₂ in response to mercury and copper treatments at the peribacteroidal membranes, to our knowledge shown for the first time. Therefore, our results revealed that an overproduction of H₂O₂ in response to copper or mercury-treatment may account for lowering of nitrogen fixation rates in heavy-metal affected root nodules. Copyright © 2013 Elsevier Ltd. All rights reserved.

  17. Laser-enhanced ionization detection of trace copper in high salt matrices.

    Science.gov (United States)

    Havrilla, G J; Carter, C C

    1987-09-01

    Laser-enhanced ionization (LEI) is used to determine trace levels of metals in high salt matrices, an analysis that is difficult by conventional methods. Copper is presented in detail to demonstrate the capability of the method. Three-dimensional spectra of the stepwise excitation of copper are presented which illustrate the one photon, stepwise, and two-photon transitions. Seven copper transitions have been studied for analytical utility, and detection limits have been determined for each. Ionization interferences were accommodated by both matrix matching and separation of the interferences using ion exchange resin. Absolute determinations at the 0.05-ng level are possible with the use of a Teflon microsampling cup for low volume quantitative analysis. In addition to copper, silver, cobalt, iron, and nickel have been detected within the same dye tuning range. Twelve new LEI transitions have been identified for these elements along with detection limits.

  18. Acute toxicity, accumulation and tissue distribution of copper in the blue crab Callinectes sapidus acclimated to different salinities: In vivo and in vitro studies

    Energy Technology Data Exchange (ETDEWEB)

    De Martinez Gaspar Martins, Camila [Programa de Pos-Graduacao em Ciencias Fisiologicas - Fisiologia Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande (FURG), Campus Carreiros, Av. Italia km 8, 96201-900, Rio Grande, RS (Brazil); Barcarolli, Indianara Fernanda; Menezes, Eliana Jaime de; Mussoi Giacomin, Marina [Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande (FURG), Campus Carreiros, Av. Italia km 8, 96201-900, Rio Grande, RS (Brazil); Wood, Chris M. [McMaster University, Department of Biology, 1280 Main Street West, Hamilton, ON, L8S 4K1 (Canada); Bianchini, Adalto, E-mail: adaltobianchini@furg.br [Programa de Pos-Graduacao em Ciencias Fisiologicas - Fisiologia Animal Comparada, Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande (FURG), Campus Carreiros, Av. Italia km 8, 96201-900, Rio Grande, RS (Brazil); Instituto de Ciencias Biologicas, Universidade Federal do Rio Grande (FURG), Campus Carreiros, Av. Italia km 8, 96201-900, Rio Grande, RS (Brazil)

    2011-01-17

    In vivo and in vitro studies were performed to evaluate acute toxicity, organ-specific distribution, and tissue accumulation of copper in Callinectes sapidus acclimated to two different experimental salinities (2 and 30 ppt). Blue crabs were quite tolerant to copper. Acute dissolved copper toxicity (96-h LC{sub 50} and its corresponding 95% confident interval) was higher at salinity 2 ppt (5.3 (3.50-8.05) {mu}M Cu) than at 30 ppt (53.0 (27.39-102.52) {mu}M Cu). The difference between salinities can be completely explained based on the water chemistry because it disappeared when 96-h LC{sub 50} values were expressed as the free Cu{sup 2+} ion (3.1 (1.93-4.95) {mu}M free Cu at 2 ppt versus 5.6 (2.33-13.37) {mu}M free Cu at 30 ppt) or the Cu{sup 2+} activity (1.4 (0.88-2.26) {mu}M Cu activity at 2 ppt versus 1.7 (0.71-4.07) {mu}M Cu activity at 30 ppt). The relationships between gill Cu burden and % mortality were very similar at 2 and 30 ppt, in accord with the Biotic Ligand Model. In vivo experiments showed that copper concentration in the hemolymph is not dependent on metal concentration in the surrounding medium at either experimental salinity. They also showed that copper flux into the gills is higher than into other tissues analyzed, and that anterior and posterior gills are similarly important sites of copper accumulation at both experimental salinities. In vitro experiments with isolated-perfused gills showed that there is a positive relationship between copper accumulation in this tissue and the metal concentration in the incubation media for both anterior and posterior gills. A similar result was observed at both low and high salinities. Furthermore, in vitro experiments showed that copper accumulation in posterior gills is also positively and strongly dependent on the incubation time with copper. Gill copper accumulation occurred at a lower rate in the first 2 h of metal exposure, increasing markedly after this 'steady-state' period. This finding

  19. Acute toxicity, accumulation and tissue distribution of copper in the blue crab Callinectes sapidus acclimated to different salinities: in vivo and in vitro studies.

    Science.gov (United States)

    Martins, Camila De Martinez Gaspar; Barcarolli, Indianara Fernanda; de Menezes, Eliana Jaime; Giacomin, Marina Mussoi; Wood, Chris M; Bianchini, Adalto

    2011-01-17

    In vivo and in vitro studies were performed to evaluate acute toxicity, organ-specific distribution, and tissue accumulation of copper in Callinectes sapidus acclimated to two different experimental salinities (2 and 30 ppt). Blue crabs were quite tolerant to copper. Acute dissolved copper toxicity (96-h LC(50) and its corresponding 95% confident interval) was higher at salinity 2 ppt (5.3 (3.50-8.05) μM Cu) than at 30 ppt (53.0 (27.39-102.52) μM Cu). The difference between salinities can be completely explained based on the water chemistry because it disappeared when 96-h LC(50) values were expressed as the free Cu(2+) ion (3.1 (1.93-4.95) μM free Cu at 2 ppt versus 5.6 (2.33-13.37) μM free Cu at 30 ppt) or the Cu(2+) activity (1.4 (0.88-2.26) μM Cu activity at 2 ppt versus 1.7 (0.71-4.07) μM Cu activity at 30 ppt). The relationships between gill Cu burden and % mortality were very similar at 2 and 30 ppt, in accord with the Biotic Ligand Model. In vivo experiments showed that copper concentration in the hemolymph is not dependent on metal concentration in the surrounding medium at either experimental salinity. They also showed that copper flux into the gills is higher than into other tissues analyzed, and that anterior and posterior gills are similarly important sites of copper accumulation at both experimental salinities. In vitro experiments with isolated-perfused gills showed that there is a positive relationship between copper accumulation in this tissue and the metal concentration in the incubation media for both anterior and posterior gills. A similar result was observed at both low and high salinities. Furthermore, in vitro experiments showed that copper accumulation in posterior gills is also positively and strongly dependent on the incubation time with copper. Gill copper accumulation occurred at a lower rate in the first 2h of metal exposure, increasing markedly after this "steady-state" period. This finding was corroborated by a significant

  20. [Influence of NTA on accumulation and subcellular distribution of copper and zinc in corn (Zea mays)].

    Science.gov (United States)

    Zhou, Jian-min; Dang, Zhi; Tao, Xue-qin; Zhou, Yong-zhang

    2005-11-01

    The differential centrifugation method was used to study the subcellular distribution of Cu and Zn in the roots, stems and leaves of corn (zea mays) growing on multi-metal contaminated soil with the addition of chelator Nitrilotriacetic Acid (NTA). The results show that the subcellular distributions of Cu and Zn have significant relationship with the ability of metal uptake and accumulation in corn. NTA could evidently promote the uptake and accumulation of Cu and Zn in corn and affect on their distribution in cell wall and vacuole. Most of Cu was bound to the cell wall fraction and secondly cytoplasm fraction and only a small quantity of Cu bound to organelle fractions. For Zn, however, most of Zn was bound to cytoplasm fraction and there was more Zn bound to organelles than Cu. Under the inducement of NTA, there were increasing Cu and Zn bound to cytoplasm fraction, which mostly came from cell wall fraction and partly came from organelle fractions.

  1. Enhanced antibacterial activity of copper/copper oxide nanowires prepared by pulsed laser ablation in water medium

    Science.gov (United States)

    Swarnkar, R. K.; Pandey, J. K.; Soumya, K. K.; Dwivedi, P.; Sundaram, S.; Prasad, Sanjay; Gopal, R.

    2016-07-01

    Copper/copper oxide nanowires (NWs) are well known for its antibacterial activity against various pathogens. In the present study, we have shown the enhanced antibacterial activity of the NWs against gram-negative bacterial strains ( Escherichia coli, Pseudomonas aeruginosa and Salmonella typhi) and gram-positive bacterial strains ( Bacillus subtilis and Staphylococcus aureus). The increase in the activity is because of the shape and size of the colloidal NWs which were prepared at room temperature in a one-step process by pulsed laser ablation of copper metal target. The purity, shape and size of the colloidal NWs were well characterized by UV-visible absorption spectroscopy and transmission electron microscopy (TEM). The NWs were of diameters in the range of 15-30 nm and lengths ranging from 200 to 600 nm. The dose-dependent antibacterial activity of these NWs was found to be more effective against gram-negative bacteria compared to gram-positive bacteria. As gram-negative bacteria have thinner layer of cell wall made up of peptidoglycan possibly which makes them more susceptible to Cu/Cu2O NWs, Cu/Cu2O NWs can be a potent candidate to be used as bactericidal or as growth inhibitor.

  2. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes.

    Science.gov (United States)

    Hansen, Anders E; Petersen, Anncatrine L; Henriksen, Jonas R; Boerresen, Betina; Rasmussen, Palle; Elema, Dennis R; af Rosenschöld, Per Munck; Kristensen, Annemarie T; Kjær, Andreas; Andresen, Thomas L

    2015-07-28

    Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years was considered to be a ubiquitous phenomenon. However, the understanding of differences in the EPR-effect between tumor types, heterogeneities within each patient group, and dependency on tumor development stage in humans is sparse. It is therefore important to enhance our understanding of the EPR-effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide the first high-resolution analysis of EPR-based tumor accumulation in large animals. We find that the EPR-effect is strong in some tumor types but cannot be considered a general feature of solid malignant tumors since we observed a high degree of accumulation heterogeneity between tumors. Six of seven included carcinomas displayed high uptake levels of liposomes, whereas one of four sarcomas displayed signs of liposome retention. We conclude that nanocarrier-radiotracers could be important in identifying cancer patients that will benefit from nanocarrier-based therapeutics in clinical practice.

  3. Cadmium, copper, and lead accumulation and bioconcentration in the vegetative and reproductive organs of Raphanus sativus: implications for plant performance and pollination.

    Science.gov (United States)

    Hladun, Kristen R; Parker, David R; Trumble, John T

    2015-04-01

    Several studies have found high levels of cadmium (Cd), copper (Cu), and lead (Pb) in honey bee hives located near urbanized or industrial areas. Insect herbivores and pollinators may come in contact with environmental contaminants in the leaves and flowers they forage upon in these areas. Our study quantified which of these metals are accumulated in the tissues of a common weedy plant that can serve as a route of exposure for insects. We grew Raphanus sativus (crop radish) in semi-hydroponic sand culture in the greenhouse. Plants were irrigated with nutrient solutions containing Cd, Cu, or Pb at four concentrations (control, low, medium, high). Plant performance, floral traits, and metal accumulation were measured in various vegetative and reproductive plant organs. Floral traits and flower number were unaffected by all metal treatments. Copper accumulated at the highest concentrations in flowers compared to the other two metals. Copper and Cd had the highest translocation indices, as well as higher bioconcentration factors compared to Pb, which was mostly immobile in the plant. Copper posed the highest risk due to its high mobility within the plant. In particular, accumulation of metals in leaves and flowers suggests that herbivores and pollinators visiting and foraging on these tissues may be exposed to these potentially toxic compounds.

  4. [Toxicity and accumulation of copper and nickel in wheat plants cropped on alkaline and acidic field soils].

    Science.gov (United States)

    Huang, Jin-Sun; Wei, Dong-Pu; Guo, Xue-Yan; Ma, Yi-Bing

    2012-04-01

    Field experiments were conducted to study the toxicity of added copper (Cu) and nickel (Ni) in soils to wheat and metal accumulation in wheat plants. The results showed that the yields of wheat straw and grain were decreased with the increasing concentration of Cu and Ni added to soils. The added Cu concentrations yielding 10% inhibition of wheat yield (EC10) were 499.6 mg x kg(-1) for alkaline soils (Dezhou, pH 8.90), and 55.7 mg x kg(-1) for acidic soils (Qiyang, pH 5.31). The toxicity of Cu or Ni in acidic soils were significantly higher than that in alkaline soils. With increasing addition of Cu or Ni, the contents of Cu in wheat grains initially increased and then keep at constant level, while the accumulation of Ni in grains linearly increased. The contents of Cu and Ni in Qiyang wheat grains were 6.07-9.26 mg x kg(-1) and 0.53-31.78 mg x kg(-1), and those of in Dezhou were 5.24-10. 52 mg x kg(-1) and 0.16-25.33 mg x kg(-1). In both field experimental sites, the contents of Cu in wheat grains meet the national standard for food safety. These findings showed that Cu is more relevant to ecological risk assessments than to food safety assessments for wheat grown in soils that have been contaminated with Cu.

  5. Suppressive Effects of Copper Sulfate Accumulation on the Spermatogenesis of Rats.

    Science.gov (United States)

    Liu, J Y; Yang, X; Sun, X D; Zhuang, C C; Xu, F B; Li, Y F

    2016-12-01

    This study investigated the effect of copper sulfate (CuSO4) in the rat spermatogenesis. Forty male rats, weighing 70-80 g, were randomly divided into four groups: control group (CG, 0 mg/kg BW), low-dose group (LG, 100 mg/kg BW), mid-dose group (MG, 200 mg/kg BW), and high-dose group (HG, 400 mg/kg BW). Rats were administered CuSO4 by gavage for 30 days. A variety of measurements were taken including the testis coefficients, the sperm count, the abnormal malformation rate, testosterone (T), luteinizing hormone (LH), and follicle-stimulating hormone (FSH) concentrations in the serum. In addition, glutathione peroxidase (GSH-Px) and superoxide dismutase (SOD) activities, and malondialdehyde (MDA) concentration in the testis were determined. The results showed that in the CuSO4-treated groups, the testis coefficients, sperm count, T, LH, and FSH concentrations, and GSH-Px and SOD activities decreased, while the abnormal malformation rate and MDA concentration increased, compared with the CG. It indicates that CuSO4 exposure impairs the sperm quality and inhibits secretion of sex hormone and gonadotropin, and testis anti-oxidative function, suppressing the rat spermatogenesis.

  6. Zinc supplementation decreases hepatic copper accumulation in LEC rat: a model of Wilson's disease.

    Science.gov (United States)

    Gonzalez, Blanca P Esparza; Niño Fong, Rodolfo; Gibson, Candace J; Fuentealba, I Carmen; Cherian, M George

    2005-01-01

    The effect of dietary zinc (Zn) supplementation on copper (Cu)-induced liver damage was investigated in Long-Evans Cinnamon rats (LEC), a model for Wilson's disease (WD). Four-week-old LEC (N=64) and control Long-Evans (LE) (N=32) female rats were divided into two groups; one group was fed with a Zn-supplemented diet (group I) and the other was given a normal rodent diet (group II). LEC rats were killed at 6, 8, 10, 12, 18, and 20 wk of age; the LE control rats were killed at 6, 12, 18, and 20 wk of age. Cu concentration in the liver was reduced in LEC rats fed the Zn-supplemented diet compared with LEC rats on the normal diet between 6 and 18 wk of age. Metallothionein (MT) concentration in the livers of LEC rats in group I increased between 12 and 20 wk of age, whereas hepatic MT concentration in LEC rats from group II decreased after 12 wk. Hepatocyte apoptosis, as determined by TUNEL, was reduced in Zn-supplemented LEC rats at all ages. Cholangiocellular carcinoma was observed only in LEC rats in group II at wk 20. These results suggest that Zn supplementation can reduce hepatic Cu concentration and delay the onset of clinical and pathological changes of Cu toxicity in LEC rats. Although the actual mechanism of protection is unknown, it could be explained by sequestration of dietary Cu by intestinal MT, induced by high dietary Zn content.

  7. Enhanced triacylglycerol accumulation in vegetative tissues of plants

    Science.gov (United States)

    Xu, Changcheng; Fan, Jilian; Yan, Chengshi; Shanklin, John

    2017-03-14

    In the tgd1-1 mutant that displays substantially enhanced TAG synthesis and turnover, disruption of SUGAR-DEPENDENT1 (SDP1) TAG lipase or PEROXISOMAL TRANSPORTER1 (PXA1) severely decreases FA turnover, leading to an increase in leaf TAG content up to 9% of dry weight and total leaf lipid by three-fold. The membrane lipid content and composition of tgd1-1 sdp1-4 and tgd1-1 pxa1-2 double mutants are altered and they are compromised in growth and development and fertility.

  8. Enhanced triacylglycerol accumulation in vegetative tissues of plants

    Energy Technology Data Exchange (ETDEWEB)

    Xu, Changcheng; Fan, Jilian; Yan, Chengshi; Shanklin, John

    2017-03-14

    In the tgd1-1 mutant that displays substantially enhanced TAG synthesis and turnover, disruption of SUGAR-DEPENDENT1 (SDP1) TAG lipase or PEROXISOMAL TRANSPORTER1 (PXA1) severely decreases FA turnover, leading to an increase in leaf TAG content up to 9% of dry weight and total leaf lipid by three-fold. The membrane lipid content and composition of tgd1-1 sdp1-4 and tgd1-1 pxa1-2 double mutants are altered and they are compromised in growth and development and fertility.

  9. Inhibition of TDP-43 accumulation by bis(thiosemicarbazonato-copper complexes.

    Directory of Open Access Journals (Sweden)

    Sarah J Parker

    Full Text Available Amyotrophic lateral sclerosis (ALS is a progressive, fatal, motor neuron disease with no effective long-term treatment options. Recently, TDP-43 has been identified as a key protein in the pathogenesis of some cases of ALS. Although the role of TDP-43 in motor neuron degeneration is not yet known, TDP-43 has been shown to accumulate in RNA stress granules (SGs in cell models and in spinal cord tissue from ALS patients. The SG association may be an early pathological change to TDP-43 metabolism and as such a potential target for therapeutic intervention. Accumulation of TDP-43 in SGs induced by inhibition of mitochondrial activity can be inhibited by modulation of cellular kinase activity. We have also found that treatment of cells and animal models of neurodegeneration, including an ALS model, with bioavailable bis(thiosemicarbazonatocopper(II complexes (Cu(II(btscs can modulate kinase activity and induce neuroprotective effects. In this study we examined the effect of diacetylbis(-methylthiosemicarbazonatocopper(II (Cu(II(atsm and glyoxalbis(-methylthiosemicarbazonatocopper(II (Cu(II(gtsm on TDP-43-positive SGs induced in SH-SY5Y cells in culture. We found that the Cu(II(btscs blocked formation of TDP-43-and human antigen R (HuR-positive SGs induced by paraquat. The Cu(II(btscs protected neurons from paraquat-mediated cell death. These effects were associated with inhibition of ERK phosphorylation. Co-treatment of cultures with either Cu(II(atsm or an ERK inhibitor, PD98059 both prevented ERK activation and blocked formation of TDP-43-and HuR-positive SGs. Cu(II(atsm treatment or ERK inhibition also prevented abnormal ubiquitin accumulation in paraquat-treated cells suggesting a link between prolonged ERK activation and abnormal ubiquitin metabolism in paraquat stress and inhibition by Cu. Moreover, Cu(II(atsm reduced accumulation of C-terminal (219-414 TDP-43 in transfected SH-SY5Y cells. These results demonstrate that Cu(II(btsc complexes

  10. Accumulation and Toxicity of Copper Oxide Engineered Nanoparticles in a Marine Mussel

    Directory of Open Access Journals (Sweden)

    Shannon K. Hanna

    2014-06-01

    Full Text Available Cu is an essential trace element but can be highly toxic to aquatic organisms at elevated concentrations. Greater use of CuO engineered nanoparticles (ENPs may lead to increased concentrations of CuO ENPs in aquatic environments causing potential ecological injury. We examined the toxicity of CuO ENPs to marine mussels and the influence of mussels on the fate and transport of CuO ENPs. We exposed marine mussels to 1, 2, or 3 mg L−1 CuO ENPs for four weeks, and measured clearance rate, rejection, excretion and accumulation of Cu, and mussel shell growth. Mussel clearance rate was 48% less, and growth was 68% less, in mussels exposed to 3 mg L−1 than in control animals. Previous studies show 100% mortality at 1 mg Cu L−1, suggesting that CuO ENPs are much less toxic than ionic Cu, probably due to the slow dissolution rate of the ENPs. Mussels rejected and excreted CuO ENPs in biodeposits containing as much as 110 mg Cu g−1, suggesting the potential for magnification in sediments. Mussels exposed to 3 mg L−1 CuO ENPs accumulated 79.14 ± 12.46 µg Cu g−1 dry weight, which was 60 times more Cu than in control animals. Our results suggest that mussels have the potential to influence the fate and transport of CuO ENPs and potentially cause magnification of CuO ENPs in mussel bed communities, creating a significant source of Cu to marine benthos.

  11. Accumulation of Copper in Gill, Liver, Spleen, Kidney and Muscle Tissues of Clarias gariepinus Exposed to the Metal Singly and in Mixture with Chitosan.

    Science.gov (United States)

    Tunçsoy, Mustafa; Duran, Servet; Ay, Özcan; Cicik, Bedii; Erdem, Cahit

    2016-10-01

    Accumulation of copper (Cu), applied singly and in mixture with chitosan (CT), in gill, liver, spleen, kidney and muscle tissues of Clarias gariepinus was studied after exposing the fish to no Cu (control), 5 ppm Cu, 5 ppm Cu + 75 ppm CT mixture over 1, 7 and 15 days. Metal levels in tissues were determined using an ICP-AES spectrophotometer. No mortality was observed during the experiments. Highest accumulation of Cu was observed in liver while lowest accumulation was observed in muscle tissue. Exposure to Cu-CT mixture decreased Cu accumulation in liver at all exposure periods and in kidney on the 15th day compared to Cu alone. Exposure to Cu alone and Cu-CT mixture had no effect on Cu accumulation in spleen or muscle tissue. Copper accumulation increased in gill tissue compared to control when exposed to Cu alone at all exposure periods, and exposure to the Cu-CT mixture significantly increased Cu accumulation in this tissue at all exposure periods compared to Cu alone.

  12. Positron Emission Tomography Based Elucidation of the Enhanced Permeability and Retention Effect in Dogs with Cancer Using Copper-64 Liposomes

    DEFF Research Database (Denmark)

    Hansen, Anders Elias; Petersen, Anncatrine Luisa; Henriksen, Jonas Rosager;

    2015-01-01

    -effect in large animals and humans with spontaneously developed cancer. In the present paper, we describe a novel loading method of copper-64 into PEGylated liposomes and use these liposomes to evaluate the EPR-effect in 11 canine cancer patients with spontaneous solid tumors by PET/CT imaging. We thereby provide......Since the first report of the enhanced permeability and retention (EPR) effect, the research in nanocarrier based antitumor drugs has been intense. The field has been devoted to treatment of cancer by exploiting EPR-based accumulation of nanocarriers in solid tumors, which for many years...... included carcinomas displayed high uptake levels of liposomes, whereas one of four sarcomas displayed signs of liposome retention. We conclude that nanocarrier-radiotracers could be important in identifying cancer patients that will benefit from nanocarrier-based therapeutics in clinical practice....

  13. Spontaneous hepatic copper accumulation in Long-Evans Cinnamon rats with hereditary hepatitis. A model of Wilson's disease.

    OpenAIRE

    Li, Y; Togashi, Y; S. Sato; Emoto, T; J. H. Kang; TAKEICHI N.; Kobayashi, H; Y. Kojima; Une, Y.; Uchino, J

    1991-01-01

    Long-Evans Cinnamon (LEC) rats, an inbred strain of a mutant rat isolated from Long-Evans rats, develop hereditary hepatitis. To elucidate the role of copper metabolism in the development of the hepatitis in LEC rats, we examined the copper concentration in the tissues and serum levels of copper and ceruloplasmin. Copper concentration in the liver of LEC rats was over 40 times that of normal Long-Evans Agouti (LEA) rats, while the serum ceruloplasmin and copper concentrations in LEC rats decr...

  14. Iron prevents ascorbic acid (vitamin C) induced hydrogen peroxide accumulation in copper contaminated drinking water.

    Science.gov (United States)

    Jansson, Patric J; Lindqvist, Christer; Nordström, Tommy

    2005-11-01

    Ascorbic acid (vitamin C) induced hydrogen peroxide (H(2)O(2)) formation was measured in household drinking water and metal supplemented Milli-Q water by using the FOX assay. Here we show that ascorbic acid readily induces H(2)O(2) formation in Cu(II) supplemented Milli-Q water and poorly buffered household drinking water. In contrast to Cu(II), iron was not capable to support ascorbic acid induced H(2)O(2) formation during acidic conditions (pH: 3.5-5). In 12 out of the 48 drinking water samples incubated with 2 mM ascorbic acid, the H(2)O(2) concentration exceeded 400 microM. However, when trace amounts of Fe(III) (0.2 mg/l) was present during incubation, the ascorbic acid/Cu(II)-induced H(2)O(2) accumulation was totally blocked. Of the other common divalent or trivalent metal ions tested, that are normally present in drinking water (calcium, magnesium, zinc, cobalt, manganese or aluminum), only calcium and magnesium displayed a modest inhibitory activity on the ascorbic acid/Cu(II)-induced H(2)O(2) formation. Oxalic acid, one of the degradation products from ascorbic acid, was confirmed to actively participate in the iron induced degradation of H(2)O(2). Ascorbic acid/Cu(II)-induced H(2)O(2) formation during acidic conditions, as demonstrated here in poorly buffered drinking water, could be of importance in host defense against bacterial infections. In addition, our findings might explain the mechanism for the protective effect of iron against vitamin C induced cell toxicity.

  15. Enhanced thermoelectric performance of spark plasma sintered copper-deficient nanostructured copper selenide

    Science.gov (United States)

    Tyagi, Kriti; Gahtori, Bhasker; Bathula, Sivaiah; Jayasimhadri, M.; Singh, Niraj Kumar; Sharma, Sakshi; Haranath, D.; Srivastava, A. K.; Dhar, Ajay

    2015-06-01

    We report the thermoelectric properties of nanostructured Cu-deficient Cu2Se, which was synthesized by high energy ball milling followed by spark plasma sintering. Our method obtained a significant enhancement in the thermoelectric figure of merit (ZT), i.e., ~1.4 at 973 K, which was ~30% higher than its bulk counterpart. This enhancement in the thermoelectric performance was due mainly to a significant reduction in the lattice thermal conductivity, which was attributed to enhanced phonon scattering at various length scales by nanoscale defects as well as abundant nanograin boundaries. The nanoscale defects were characterized by transmission electron microscopy of the nanostructured Cu2-xSe samples, which formed the basis of the ZT enhancement.

  16. Copper and Copper Proteins in Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Sergio Montes

    2014-01-01

    Full Text Available Copper is a transition metal that has been linked to pathological and beneficial effects in neurodegenerative diseases. In Parkinson’s disease, free copper is related to increased oxidative stress, alpha-synuclein oligomerization, and Lewy body formation. Decreased copper along with increased iron has been found in substantia nigra and caudate nucleus of Parkinson’s disease patients. Copper influences iron content in the brain through ferroxidase ceruloplasmin activity; therefore decreased protein-bound copper in brain may enhance iron accumulation and the associated oxidative stress. The function of other copper-binding proteins such as Cu/Zn-SOD and metallothioneins is also beneficial to prevent neurodegeneration. Copper may regulate neurotransmission since it is released after neuronal stimulus and the metal is able to modulate the function of NMDA and GABA A receptors. Some of the proteins involved in copper transport are the transporters CTR1, ATP7A, and ATP7B and the chaperone ATOX1. There is limited information about the role of those biomolecules in the pathophysiology of Parkinson’s disease; for instance, it is known that CTR1 is decreased in substantia nigra pars compacta in Parkinson’s disease and that a mutation in ATP7B could be associated with Parkinson’s disease. Regarding copper-related therapies, copper supplementation can represent a plausible alternative, while copper chelation may even aggravate the pathology.

  17. Superhydrophobic copper tubes with possible flow enhancement and drag reduction.

    Science.gov (United States)

    Shirtcliffe, Neil J; McHale, Glen; Newton, Michael I; Zhang, Yong

    2009-06-01

    The transport of a Newtonian liquid through a smooth pipe or tube is dominated by the frictional drag on the liquid against the walls. The resistance to flow against a solid can, however, be reduced by introducing a layer of gas at or near the boundary between the solid and liquid. This can occur by the vaporization of liquid at a surface at a temperature above the Leidenfrost point, by a cushion of air (e.g. below a hovercraft), or by producing bubbles at the interface. These methods require a continuous energy input, but a more recent discovery is the possibility of using a superhydrophobic surface. Most reported research uses small sections of lithographically patterned surfaces and rarely considers pressure differences or varying flow rates. In this work we present a method for creating a uniform superhydrophobic nanoribbon layer on the inside of round copper tubes of millimetric internal radius. Two types of experiments are described, with the first involving a simultaneous comparison of four tubes with different surface finishes (as received, as received with hydrophobic coating, nanoribbon, and nanoribbon with a hydrophobic coating) under constant flow rate conditions using water and water-glycerol mixtures. The results show that the superhydrophobic nanoribbon with a hydrophobic coating surface finish allows greater flow at low pressure differences but that the effect disappears as the pressure at the inlet of the tube is increased. The second experiment is a simple visual demonstration of the low-pressure behavior using two nominally identical tubes in terms of length and cross-section, but with one tube possessing a superhydrophobic internal surface finish. In this experiment a reservoir is allowed to feed the two tubes with open ends via a T-piece and it is observed that, once flow commences, it preferentially occurs down the superhydrophobic tube.

  18. Zinc, cadmium, and copper mobility and accumulation in reeds (Phragmites australis) in urban sediments from two stormwater infiltration basins

    Science.gov (United States)

    Bedell, J.-P.; Saulais, S.; Delolme, C.

    2012-04-01

    organic matter and metals than "Minerve". For example, Zn contents are equal to 400 mg/kgDW in "Grézieu" whereas it is equal to 80 mg/kgDW in "Minerve". In the most contaminated basin "Grézieu", metals mobility is mainly controlled by their association with carbonates and organic matter. Thus, copper associated with organic matter may represent almost 70% of the total copper content. In the "Minerve" sediment, the metals are distributed on the different sediment components, with very stable associations on the different mineral phases. The reed accumulates more metal in the context of the most contaminated basin (Grézieu), but without any differences in bioconcentration factors. The high metal contents in "Grézieu" sediments limited also the growth of reed. Moreover, for "Grézieu" sediment, characteristics evolve with the seasons. Thus, texture decreases from June to December in parallel with an increase in organic matter and metals in the sediment deposit.

  19. Phase Transition Enhanced Thermoelectric Performance in Copper Chalcogenides

    Science.gov (United States)

    Brown, David; Day, Tristan; Borup, Kasper; Christensen, Sebastian; Iversen, Bo; Snyder, G. Jeffrey

    2014-03-01

    Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu2Se over a broad (360-410 K) temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K), and a similar but larger increase over a wider temperature range in the zT of Cu1.97Ag0.03Se (almost 1.0 at 400K). The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics. Resnick Sustainibility Institute.

  20. Seedling growth and metal accumulation of selected woody species in copper and lead/zinc mine tailings.

    Science.gov (United States)

    Shi, Xiang; Zhang, Xiaolei; Chen, Guangcai; Chen, Yitai; Wang, Ling; Shan, Xiaoquan

    2011-01-01

    A greenhouse pot experiment was conducted to evaluate the potential of selected woody plants for revegetation in copper (Cu) and lead/zinc (Pb/Zn) mine tailing areas. Five woody species (Amorpha fruticosa Linn, Vitex trifolia Linn. var. simplicifolia Cham, Glochidion puberum (Linn.) Hutch, Broussonetia papyrifera, and Styrax tonkinensis) and one herbaceous species (Sesbania cannabina Pers) were planted in Cu and Pb/Zn tailings to assess their growth, root morphology, nutrition uptake, metal accumulation, and translocation in plants. Amorpha fruticosa maintained normal growth, while the other species demonstrated stress related growth and root development. Sesbania cannabina showed the highest biomass among the plants, although it decreased by 30% in Cu tailings and 40% in Pb/Zn tailings. Calculated tolerance index (TI) values suggested that A. fruticosa, an N-fixing shrub, was the most tolerant species to both tailings (TI values 0.92-1.01), while S. cannabina had a moderate TI of 0.65-0.81 and B. papyrifera was the most sensitive species, especially to Pb/Zn tailings (TI values 0.15-0.19). Despite the high concentrations of heavy metals in the mine tailings and plants roots, only a small transfer of these elements to the aboveground parts of the woody plants was evident from the low translocation factor (TF) values. Among the woody plants, V. trifolia var. simplicifolia had the highest TF values for Zn (1.32), Cu (0.78), and Pb/Zn (0.78). The results suggested that A. fruticosa and S. cannabina, which have the highest tolerance and biomass production, respectively, demonstrated the potential for tailings revegetation in southern China.

  1. Experimental research in leaching of copper-bearing tailings enhanced by ultrasonic treatment

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie; WU Ai-xiang; WANG Yi-ming; CHEN Xue-song

    2008-01-01

    On the basis of an experiment in ultrasonic enhanced ammonia leaching of tailings, the effect of ultrasonic waves on copper dissolution was studied. The mechanism of ultrasonic enhanced tailing leaching was analyzed and a technique of ultrasonic enhanced pipe leaching of tailings was proposed. The results show that tailings with ultrasonic treatment can leach up to 89.5% of Cu, which is 13.5% more than those without the treatment. Ultrasonic technology is capable of improving leaching rates and the overall recovery of tailing leaching. Impact waves and micro jet streams can strip and erode affected surfaces of tailing particles to create new active surfaces and disturbances can intensify mass transfer processes in "dead zones". The technique of ultrasonic enhanced pipe leaching of tailings is a combination of existing agitation enhancement with ultrasonic enhancement and can im-prove mineral recovery.

  2. EGCG Enhances Cisplatin Sensitivity by Regulating Expression of the Copper and Cisplatin Influx Transporter CTR1 in Ovary Cancer.

    Directory of Open Access Journals (Sweden)

    Xuemin Wang

    Full Text Available Cisplatin is one of the first-line platinum-based chemotherapeutic agents for treatment of many types of cancer, including ovary cancer. CTR1 (copper transporter 1, a transmembrane solute carrier transporter, has previously been shown to increase the cellular uptake and sensitivity of cisplatin. It is hypothesized that increased CTR1 expression would enhance the sensitivity of cancer cells to cisplatin (cDDP. The present study demonstrates for the first time that (--epigallocatechin-3-gallate (EGCG, a major polyphenol from green tea, can enhance CTR1 mRNA and protein expression in ovarian cancer cells and xenograft mice. EGCG inhibits the rapid degradation of CTR1 induced by cDDP. The combination of EGCG and cDDP increases the accumulation of cDDP and DNA-Pt adducts, and subsequently enhances the sensitivity of ovarian cancer SKOV3 and OVCAR3 cells to the chemotherapeutic agent. In the OVCAR3 ovarian cancer xenograft nude mice model, the combination of the lower concentration of cDDP and EGCG strongly repressed the tumor growth and exhibited protective effect on the nephrotoxicity induced by cisplatin. Overall, these findings uncover a novel chemotherapy mechanism of EGCG as an adjuvant for the treatment of ovarian cancer.

  3. Spontaneous hepatic copper accumulation in Long-Evans Cinnamon rats with hereditary hepatitis. A model of Wilson's disease.

    Science.gov (United States)

    Li, Y; Togashi, Y; Sato, S; Emoto, T; Kang, J H; Takeichi, N; Kobayashi, H; Kojima, Y; Une, Y; Uchino, J

    1991-05-01

    Long-Evans Cinnamon (LEC) rats, an inbred strain of a mutant rat isolated from Long-Evans rats, develop hereditary hepatitis. To elucidate the role of copper metabolism in the development of the hepatitis in LEC rats, we examined the copper concentration in the tissues and serum levels of copper and ceruloplasmin. Copper concentration in the liver of LEC rats was over 40 times that of normal Long-Evans Agouti (LEA) rats, while the serum ceruloplasmin and copper concentrations in LEC rats decreased significantly. The hepatocytes of LEC rats show steatosis in cytoplasm and pleomorphism of mitochondria, resembling the histologic features of the liver in Wilson's disease. These findings suggest that the hereditary hepatitis in LEC rats is closely associated with copper toxicity, and may be dealing with a rat form of Wilson's disease. Thus the LEC rats will provide a unique and useful animal model for clarifying the mechanism and for developing treatment strategies for Wilson's disease and other abnormal copper metabolism in humans.

  4. Enhanced Tumor Accumulation of Sub-2 nm Gold Nanoclusters for Cancer Radiation Therapy

    CERN Document Server

    Zhang, Xiao-Dong; Luo, Zhentao; Wu, Di; Shen, Xiu; Song, Sha-Sha; Sun, Yuan-Ming; Liu, Pei-Xun; Zhao, Jing; Huo, Shuaidong; Fan, Saijun; Fan, Feiyue; Liang, Xing-Jie; Xie, Jianping

    2013-01-01

    A new type of metabolizable and efficient radiosensitizer for cancer radiotherapy is presented in this study by combining ultrasmall Au nanoclusters (NCs, <2 nm) with biocompatible coating ligands (glutathione, GSH). The new nano-construct (GSH-coated Au25 NCs) inherits attractive features of both the Au core (strong radiosensitizing effect) and GSH shell (good biocompatibility). It can preferentially accumulate in tumor via the improved EPR effect, which leads to strong enhancement for cancer radiotherapy. After the treatment, the small-sized GSH-Au25 NCs can be efficiently cleared by the kidney, minimizing any potential side effects due to the accumulation of Au25 NCs in the body.

  5. Micellar-enhanced ultrafiltration process (MEUF) for removing copper from synthetic wastewater containing ligands.

    Science.gov (United States)

    Liu, Chuan-Kun; Li, Chi-Wang; Lin, Ching-Yu

    2004-11-01

    The effects of the type and concentration of ligands on the removal of Cu by micellar-enhanced ultrafiltration (MEUF) with the help of either anionic or cationic surfactants were investigated. The removal efficiency of copper by anionic surfactant-(SDS-) MEUF depends on the ligand-to-Cu ratio and the ligand-to-Cu complexation constant. At fixed ligand-to-Cu ratio, the Cu removal efficiency decreases in the order of citric acid>NTA>EDTA, which is the reverse order of Cu-ligand complexation constants for these ligands. Increasing SDS-ligand ratios from 12 to 60 at fixed ligand concentration did not improve copper removal efficiency. The cationic surfactant, CPC, enhances Cu removal efficiency in systems with condition of ligand-copper ratios higher than 1.0, where Cu removal is not very efficient using SDS-MEUF process. The Cu removal efficiency with CPC-MEUF depends on both the ligand-to-Cu ratio and the type of ligands.

  6. EDTA和柠檬酸对反枝苋(Amaranthusretroflexus L.)Cu迁移富集影响研究%Effects of EDTA and Critic Acid (CA) on the Translocation and Accumulation of Copper inAmaranthusRetroflexus L. System

    Institute of Scientific and Technical Information of China (English)

    刘婕; 朱宇恩; 刘娜; 王翠红; 吴山

    2015-01-01

    Pot experiments were conducted to study the effects of ethylene diamine tetraacetic acid (EDTA) and citric acid (CA) on copper accumulation and translocation inAmaranthus retroflexusL., with exogenous copper concentrations of 0, 100, 200, 400 and 800 mg·kg-1. The concentrations of Cu with different speciations in both rhizosphere and bulk soil, and its enrichment characteristics in plant tissue were determined after adding 2.5 mmol·kg-1 CA or EDTA to different copper treatment. Results showed that the ability of copper accumulation in different plant tissues followed the sequence of roots > leaves> stems when copper contents were less than 400 mg·kg-1, while roots > stems > leaves when copper contents were 400 mg·kg-1. BCFs and TFs ofA. retroflexuswere both less than 1, which indicated thatA. retroflexuswas not a copper hyperaccumulation plant under the present experiment condition. Both EDTA and CA can effectively improve enrichment ability of the plant for copper and enhance the transportation of copper from roots to shoots; EDTA was more effective, causing 3512.71 mg·kg-1 of shoots uptake under the 800 mg·kg-1 copper content condition. The contents of total copper and exchangeable speciation inrhizosphere soil were increased for the EDTA amendment, while the content of Fe-Mn oxidizable speciation of copper decreased. The addition of CA promoted the chemical conversion of copper from Fe-Mn oxidizable speciation to carbonate speciation in rhizoshpere soil. It concluded that EDTA significantly improved the copper uptake ofA. retroflexus and increased the content of total copper in rhizosphere soil, which resulted from the joint effects of the increasing migration activity of Cu-EDTA and the copper exclusion mechanisms ofA. retroflexus.%为明确反枝苋(Amaranthusretroflexus L.)对Cu的富集能力及EDTA与柠檬酸(CA)对Cu迁移的影响,采用盆栽试验,在0、100、200、400、800 mg·kg-1 Cu处理质量分数及2.5 mmol·kg-1 EDTA和柠檬酸施加

  7. Enhanced copper micro/nano-particle mixed paste sintered at low temperature for 3D interconnects

    Science.gov (United States)

    Dai, Y. Y.; Ng, M. Z.; Anantha, P.; Lin, Y. D.; Li, Z. G.; Gan, C. L.; Tan, C. S.

    2016-06-01

    An enhanced copper paste, formulated by copper micro- and nano-particles mixture, is reported to prevent paste cracking and obtain an improved packing density. The particle mixture of two different sizes enables reduction in porosity of the micro-paste and resolves the cracking issue in the nano-paste. In-situ temperature and resistance measurements indicate that the mixed paste has a lower densification temperature. Electrical study also shows a ˜12× lower sheet resistance of 0.27 Ω/sq. In addition, scanning electron microscope image analysis confirms a ˜50% lower porosity, which is consistent with the thermal and electrical results. The 3:1 (micro:nano, wt. %) mixed paste is found to have the strongest synergistic effect. This phenomenon is discussed further. Consequently, the mixed paste is a promising material for potential low temperature 3D interconnects fabrication.

  8. Radiation-enhanced thermal processes during implantation of gold into copper

    Energy Technology Data Exchange (ETDEWEB)

    Perret, N.E.; King, B.V.; Dastoor, P.C. [Newcastle Univ., NSW (Australia). Dept. of Physics

    1996-12-31

    A copper (100) single crystal has been implanted with gold ions at temperatures ranging from 133 K to 673 K. Rutherford Backscattering Spectroscopy (RBS) has been used to observe the changes in the gold implant distribution that occur as a function of the sample temperature during implantation. Two distinct effects have been observed. Firstly the gold implant distribution, as a function of depth, broadens with sample temperature. This broadening of the gold depth profile is most marked at temperatures above 473 K. Secondly, the gold is implanted deeper into the copper crystal as the sample temperature is increased. These results are discussed in terms of radiation enhanced diffusion and radiation-induced segregation processes. 10 refs., 3 figs.

  9. MtgA Deletion-Triggered Cell Enlargement of Escherichia coli for Enhanced Intracellular Polyester Accumulation.

    Directory of Open Access Journals (Sweden)

    Ryosuke Kadoya

    Full Text Available Bacterial polyester polyhydroxyalkanoates (PHAs have been produced in engineered Escherichia coli, which turned into an efficient and versatile platform by applying metabolic and enzyme engineering approaches. The present study aimed at drawing out the latent potential of this organism using genome-wide mutagenesis. To meet this goal, a transposon-based mutagenesis was carried out on E. coli, which was transformed to produce poly(lactate-co-3-hydroxybutyrate from glucose. A high-throughput screening of polymer-accumulating cells on Nile red-containing plates isolated one mutant that produced 1.8-fold higher quantity of polymer without severe disadvantages in the cell growth and monomer composition of the polymer. The transposon was inserted into the locus within the gene encoding MtgA that takes part, as a non-lethal component, in the formation of the peptidoglycan backbone. Accordingly, the mtgA-deleted strain E. coli JW3175, which was a derivate of superior PHA-producing strain BW25113, was examined for polymer production, and exhibited an enhanced accumulation of the polymer (7.0 g/l compared to the control (5.2 g/l. Interestingly, an enlargement in cell width associated with polymer accumulation was observed in this strain, resulting in a 1.6-fold greater polymer accumulation per cell compared to the control. This result suggests that the increase in volumetric capacity for accumulating intracellular material contributed to the enhanced polymer production. The mtgA deletion should be combined with conventional engineering approaches, and thus, is a promising strategy for improved production of intracellularly accumulated biopolymers.

  10. Calcium effect on the metabolic pathway of phosphorus accumulating organisms in enhanced biological phosphorus removal systems.

    Science.gov (United States)

    Zhang, Hai-Ling; Sheng, Guo-Ping; Fang, Wei; Wang, Yong-Peng; Fang, Cai-Yun; Shao, Li-Min; Yu, Han-Qing

    2015-11-01

    Phosphorus accumulating organisms (PAOs) have been found to act as glycogen-accumulating organisms (GAOs) under certain conditions, thus, the deterioration in the performance of enhanced biological phosphorus removal systems is not always attributed to the proliferation of GAOs. In this work, the effects of calcium on the metabolic pathway of PAOs were explored. It was found that when the influent Ca(2+) concentration was elevated, the tendency and extent of extracellular calcium phosphate precipitation increased, and the intracellular inert Ca-bound polyphosphate was synthesized, while the microbial population remained almost unchanged. The changes in the ratios of phosphorus released/acetate uptaken, the glycogen degraded/acetate uptaken and the poly-β-hydroxyalkanoates synthesized/acetate uptaken during the anaerobic period confirm that, as the influent Ca(2+) concentration was increased, the polyphosphate-accumulating metabolism was partially shifted to the glycogen-accumulating metabolism. At an influent Ca(2+) around 50 mg/L, in addition to the extracellular calcium phosphate precipitation, the intracellular inert Ca-bound polyphosphate synthesis might also be involved in the metabolic change of PAOs. The results of the present work would be beneficial to better understand the biochemical metabolism of PAOs in enhanced biological phosphorus removal systems. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. Chemicals to enhance microalgal growth and accumulation of high-value bioproducts

    Directory of Open Access Journals (Sweden)

    Xinheng eYu

    2015-02-01

    Full Text Available Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogues regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae.

  12. Chemicals to enhance microalgal growth and accumulation of high-value bioproducts.

    Science.gov (United States)

    Yu, Xinheng; Chen, Lei; Zhang, Weiwen

    2015-01-01

    Photosynthetic microalgae have attracted significant attention as they can serve as important sources for cosmetic, food and pharmaceutical products, industrial materials and even biofuel biodiesels. However, current productivity of microalga-based processes is still very low, which has restricted their scale-up application. In addition to various efforts in strain improvement and cultivation optimization, it was proposed that the productivity of microalga-based processes can also be increased using various chemicals to trigger or enhance cell growth and accumulation of bioproducts. Herein, we summarized recent progresses in applying chemical triggers or enhancers to improve cell growth and accumulation of bioproducts in algal cultures. Based on their enhancing mechanisms, these chemicals can be classified into four categories:chemicals regulating biosynthetic pathways, chemicals inducing oxidative stress responses, phytohormones and analogs regulating multiple aspects of microalgal metabolism, and chemicals directly as metabolic precursors. Taken together, the early researches demonstrated that the use of chemical stimulants could be a very effective and economical way to improve cell growth and accumulation of high-value bioproducts in large-scale cultivation of microalgae.

  13. Supplementation with zinc in rats enhances memory and reverses an age-dependent increase in plasma copper.

    Science.gov (United States)

    Sandusky-Beltran, Leslie A; Manchester, Bryce L; McNay, Ewan C

    2017-08-30

    Zinc and copper are essential trace elements. Dyshomeostasis in these two metals has been observed in Alzheimer's disease, which causes profound cognitive impairment. Insulin therapy has been shown to enhance cognitive performance; however, recent data suggest that this effect may be at least in part due to the inclusion of zinc in the insulin formulation used. Zinc plays a key role in regulation of neuronal glutamate signaling, suggesting a possible link between zinc and memory processes. Consistent with this, zinc deficiency causes cognitive impairments in children. The effect of zinc supplementation on short- and long-term recognition memory, and on spatial working memory, was explored in young and adult male Sprague Dawley rats. After behavioral testing, hippocampal and plasma zinc and copper were measured. Age increased hippocampal zinc and copper, as well as plasma copper, and decreased plasma zinc. An interaction between age and treatment affecting plasma copper was also found, with zinc supplementation reversing elevated plasma copper concentration in adult rats. Zinc supplementation enhanced cognitive performance across tasks. These data support zinc as a plausible therapeutic intervention to ameliorate cognitive impairment in disorders characterized by alterations in zinc and copper, such as Alzheimer's disease. Copyright © 2017 Elsevier B.V. All rights reserved.

  14. Microwave enhanced recovery of nickel-copper ore: communition and floatability aspects.

    Science.gov (United States)

    Henda, R; Hermas, A; Gedye, R; Islam, M R

    2005-01-01

    A study describing the effect of microwave radiation, at a frequency of 2450 MHz, on the processes of communication and flotation of a complex sulphide nickel-copper ore is presented. Ore communication has been investigated under standard radiation-free conditions and after ore treatment in a radiated environment as a function of ore size, exposure time to radiation, and microwave power. The findings show that communication is tremendously improved by microwave radiation with values of the relative work index as low as 23% at a microwave power of 1.406 kW and after 10 s of exposure time. Communication is affected by exposure time and microwave power in a nontrivial manner. In terms of ore floatability, the experimental tests have been carried out on a sample of 75 microm in size under different exposure times. The results show that both ore concentrate recoveries and grades of nickel and copper are significantly enhanced after microwave treatment of the ore with relative increases in recovered concentrate, grade of nickel, and grade of copper of 26 wt%, 15 wt%, and 27%, respectively, at a microwave power of 1330 kW and after 30 s of exposure time.

  15. Enhanced decolorization of methyl orange using zero-valent copper nanoparticles under assistance of hydrodynamic cavitation.

    Science.gov (United States)

    Li, Pan; Song, Yuan; Wang, Shuai; Tao, Zheng; Yu, Shuili; Liu, Yanan

    2015-01-01

    The rate of reduction reactions of zero-valent metal nanoparticles is restricted by their agglomeration. Hydrodynamic cavitation was used to overcome the disadvantage in this study. Experiments for decolorization of methyl orange azo dye by zero-valent copper nanoparticles were carried out in aqueous solution with and without hydrodynamic cavitation. The results showed that hydrodynamic cavitation greatly accelerated the decolorization rate of methyl orange. The size of nanoparticles was decreased after hydrodynamic cavitation treatment. The effects of important operating parameters such as discharge pressure, initial solution pH, and copper nanoparticle concentration on the degradation rates were studied. It was observed that there was an optimum discharge pressure to get best decolorization performance. Lower solution pH were favorable for the decolorization. The pseudo-first-order kinetic constant for the degradation of methyl orange increased linearly with the copper dose. UV-vis spectroscopic and Fourier transform infrared (FT-IR) analyses confirmed that many degradation intermediates were formed. The results indicated hydroxyl radicals played a key role in the decolorization process. Therefore, the enhancement of decolorization by hydrodynamic cavitation could due to the deagglomeration of nanoparticles as well as the oxidation by the in situ generated hydroxyl radicals. These findings greatly increase the potential of the Cu(0)/hydrodynamic cavitation technique for use in the field of treatment of wastewater containing hazardous materials.

  16. Effects of enhanced zinc and copper in drinking water on spatial memory and fear conditioning

    Science.gov (United States)

    Chrosniak, L.D.; Smith, L.N.; McDonald, C.G.; Jones, B.F.; Flinn, J.M.

    2006-01-01

    Ingestion of enhanced zinc can cause memory impairments and copper deficiencies. This study examined the effect of zinc supplementation, with and without copper, on two types of memory. Rats raised pre- and post-natally on 10 mg/kg ZnCO3 or ZnSO4 in the drinking water were tested in a fear-conditioning experiment at 11 months of age. Both zinc groups showed a maladaptive retention of fearful memories compared to controls raised on tap water. Rats raised on 10 mg/kg ZnCO3, 10 mg/kg ZnCO3 + 0.25 mg/kg CuCl2, or tap water, were tested for spatial memory ability at 3 months of age. Significant improvements in performance were found in the ZnCO3 + CuCl2 group compared to the ZnCO3 group, suggesting that some of the cognitive deficits associated with zinc supplementation may be remediated by addition of copper. ?? 2005 Elsevier B.V. All rights reserved.

  17. Use of Azolla to assess toxicity and accumulation of metals from artificial and natural sediments containing cadmium, copper, and zinc

    Energy Technology Data Exchange (ETDEWEB)

    Powell, G.M. [S.M. Stoller Corp., Boulder, CO (United States); Nimmo, D.W.R.; Flickinger, S.A.; Brinkman, S.F.

    1998-12-31

    The aquatic macrophyte Azolla mexicana was studied to determine if it could indicate toxicity and bioavailability of cadmium, copper, and zinc in sediments. Plants were exposed to metal-fortified artificial sediment and to natural sediment contaminated with tailings from a Superfund site near Deer Lodge, Montana. Dry weights (mass) of biomass were used to determine effects of the metal concentrations and tissue metals were measured to determine metal uptake from the sediments. Plants exposed to artificial sediments fortified with cadmium and copper showed the greatest reduction in dry mass while zinc showed the least. And, plants exposed to copper singly in artificial sediments lost both zinc and cadmium for their tissues. Plants exposed to metal-contaminated natural sediment developed necrotic and chlorotic tissue within 24 hours in 75% and 100% dilutions but significant effects (P < 0.0001) using dry mass were found as low as 3.13%.

  18. Surface-enhanced resonance Raman spectroscopy of copper chlorophyllin on silver and gold colloids

    Energy Technology Data Exchange (ETDEWEB)

    Hildebrandt, P.; Spiro, T.G.

    1988-06-16

    Surface-enhanced resonance Raman spectra (SERRS) are reported for copper chlorophyllin a (CuChl) adsorbed on silver and gold colloids. The surface species are shown to be monomeric, by comparison with solution resonance Raman (RR) spectra, although lowering the pH of the gold colloid to 2.0 induces spectral changes suggestive of surface aggregation. The similarity of CuChl monomer RR and SERRS spectra is consistent with electromagnetic enhancement of the RR spectra via the metal particles, with no indication of a chemical interaction that would perturb the electronic states. The SERRS spectra change markedly with excitation wavelength in ways that can be explained on the basis of the different Raman enhancement pattern expected for resonance with the different chlorin excited states. The SERRS spectra are highly resolved and are useful in suggesting new assignments for chlorin vibrational modes.

  19. APPLICATION OF METAL RESISTANT BACTERIA BY MUTATIONAL ENHANCMENT TECHNIQUE FOR BIOREMEDIATION OF COPPER AND ZINC FROM INDUSTRIAL WASTES

    Directory of Open Access Journals (Sweden)

    M. R. Shakibaie ، A. Khosravan ، A. Frahmand ، S. Zare

    2008-10-01

    Full Text Available In this research, using mutation in the metal resistant bacteria, the bioremediation of the copper and zinc from copper factory effluents was investigated. Wastewater effluents from flocculation and rolling mill sections of a factory in the city of Kerman were collected and used for further experiments. 20 strains of Pseudomonas spp. were isolated from soil and effluents surrounding factory and identified by microbiological methods. Minimum inhibitory concentrations for copper (Cu and zinc (Zn were determined by agar dilution method. Those strains that exhibited highest minimum inhibitory concentrations values to the metals (5mM were subjected to 400-3200 mg/L concentrations of the three mutagenic agents, acriflavine, acridine orange and ethidium bromide. After determination of subinhibitory concentrations, the minimum inhibitory concentrations values for copper and zinc metal ions were again determined, which showed more than 10 fold increase in minimum inhibitory concentrations value (10 mM for Cu and 20 mM for Zn with P≤0.05. The atomic absorption spectroscopy of dried biomass obtained from resistant strains after exposure to mutagenic agents revealed that strains 13 accumulate the highest amount of intracellular copper (0.35% Cu/mg dried biomass and strain 10 showed highest accumulation of zinc (0.3% Zn/mg dried biomass respectively with P≤0.05. From above results it was concluded that the treatment of industrial waste containing heavy metals by artificially mutated bacteria may be appropriate solution for effluent disposal problems.

  20. Engineering TCE-degrading rhizobacteria for heavy metal accumulation and enhanced TCE degradation.

    Science.gov (United States)

    Lee, Wonkyu; Wood, Thomas K; Chen, Wilfred

    2006-10-20

    Many superfund sites are currently co-contaminated with organic pollutants such as trichloroethene (TCE) and heavy metals. A promising strategy to address these mixed-waste situations is the use of TCE-degrading rhizobacteria that will survive and thrive in soil heavily polluted with heavy metals. In this work, a gene coding for the metal-binding peptide, EC20, was introduced into rhizobacteria engineered for TCE degradation, resulting in strains with both metal accumulation and TCE degradation capabilities. EC20 was displayed onto the cell surface of Pseudomonas strain Pb2-1 and Rhizobium strain 10320D using an ice-nucleation protein (INP) anchor. Expression of EC20 was confirmed by Western blot analysis and cells with EC20 expression showed sixfold higher cadmium accumulation than non-engineered strains in the presence of 16 microM CdCl(2). As expected, the TCE degradation rate was reduced in the presence of cadmium for cells without EC20 expression. However, expression of EC20 (higher cadmium accumulation) completely restored the level of TCE degradation. These results demonstrated that EC20 expression enhanced not only cadmium accumulation but also reduced the toxic effect of cadmium on TCE degradation. We expect that similar improvements will be observed when these engineered rhizobacteria are inoculated onto plant roots.

  1. Effect of chromium on accumulation and antioxidants in Cucumis utillissimus L.: Response under enhanced bioavailability condition

    Institute of Scientific and Technical Information of China (English)

    Geetgovind Sinam; Sarita Sinha; Shekhar Mallick

    2011-01-01

    This study compares the accumulation of Ct(VI) and biochemical changes (total chlorophyll, carotenoid, protein, malondialdehyde (MDA) and cysteine contents) and roles of antioxidant enzymes (superoxide dismutase (SOD), guaiacol peroxidase (GPX), ascorbate peroxidase (APX)) in tolerance to metal induced stress in Cucumis utillissimus L. grown in Cr contaminated soil (CS) with garden soil (GS). Furthermore, Cr bioavailability was enhanced by ethylene diamine tetra-acetic acid (EDTA) addition to the soil to forecast the plant's accumulation pattern at elevated Cr environment. Accumulation of Cr in the leaves of the plant increased with increase in substrate metals concentration. It further increased with the addition of EDTA by 1437% and 487% in GS and CS, respectively at the highest treatment level. The lipid peroxidation increased proportionately with increase in Cr accumulation in the leaves. All the activity of antioxidant enzymes (SOD, GPX and APX) and the level of cysteine increased with dose dependant manner. SOD and cysteine were observed to be higher in the GS than in CS, but APX and GPX were found to be higher in CS than in GS. The increase in GPX and APX activities with the increase in Cr concentration could be assumed that these two enzymes have a major role in the defense mechanism towards stress induced by Cr in C. utillissimus.

  2. Enhanced arsenic accumulation in Saccharomyces cerevisiae overexpressing transporters Fps1p or Hxt7p.

    Science.gov (United States)

    Shah, Dhawal; Shen, Michael W Y; Chen, Wilfred; Da Silva, Nancy A

    2010-10-01

    Arsenic contamination of ground water affects the health of millions of people worldwide. Bioremediation has the potential to lower contaminant levels in cases where physical methods are either ineffective or cost prohibitive. The yeast Saccharomyces cerevisiae was engineered for enhanced arsenite accumulation by overexpression of transporters responsible for the influx of the contaminant. The transporter genes FPS1 and HXT7 were cloned under the control of the late-phase ADH2-promoter. This allowed for protein production at high biomass levels without the addition of inducer. Following the transfer of stationary phase cells to buffer, the engineered strains were capable of 3-4-fold greater arsenic uptake as compared to control cells. Further, at trace levels of the metalloid, the cells overexpressing the Fps1p transporter removed ca. 40% more arsenite from the extracellular medium than the controls. Arsenic uptake was also evaluated in cells overexpressing the transporters coupled with high-level production of cytosolic As sequestors (phytochelatins or bacterial ArsRp) to act as an intracellular sink. This led to an up to 4-fold increase in As accumulation in the resting cell culture as compared to native cells. The results demonstrate important steps needed to engineer a yeast biosorbent with enhanced accumulation capabilities for this metalloid.

  3. EDTA enhanced phytoremediation of copper contaminated soils using chickpea (Cicer aeritinum L.).

    Science.gov (United States)

    Kambhampati, Murty S; Vu, Van Tu

    2013-09-01

    The goal of this research was to determine whether or not chickpea (Cicer arietinum L.), commonly known as Garbanzo beans, is a hyper accumulator for copper (Cu) in contaminated soils amended with EDTA. Statistical analysis (2 tailed Pearson Correlation) revealed significant correlations between: Translocation index and stem biomass (r = 0.859**; p < 0.01); Tolerance index and stem biomass (r = 0.762**; p < 0.01); and bioconcentration factor of stem/soil and soil Cu concentration (r = -0.545*; p < 0.05). Therefore, C. arietinum seems to be a cost-effective and environmentally friendly hyperaccumulator for Cu at 100 ppm Cu and 10 mM EDTA.

  4. Salinity-dependent copper accumulation in the guppy Poecilia vivipara is associated with CTR1 and ATP7B transcriptional regulation.

    Science.gov (United States)

    da Silva, Evelise Sampaio; Abril, Sandra Isabel Moreno; Zanette, Juliano; Bianchini, Adalto

    2014-07-01

    Copper (Cu) accumulation and regulation of key-genes involved in Cu homeostasis were evaluated in freshwater- and saltwater-acclimated guppies Poecilia vivipara. Fish were exposed (96h) to environmentally relevant concentrations of dissolved Cu (0, 5.0, 9.0 and 20.0μg/L). In freshwater guppies, gill and liver Cu accumulation was dependent on Cu concentration in the exposure medium. In saltwater guppies, this dependence was observed only in the gut. These findings indicate that Cu accumulation was salinity- and tissue-dependent. Key genes involved in Cu metabolism were sequenced for the first time in P. vivipara. Transcripts coding for the high-affinity copper transporter (CTR1) and copper-transporting ATPase (ATP7B) were identified using polymerase chain reaction (PCR) and gene sequencing. The full-length CTR1 open reading frame (1560bp) and a partial ATP7B (690bp) were discovered. Predicted amino acid sequences shared high identities with the CTR1 of Fundulus heteroclitus (81%) and the ATP7B of Sparus aurata (87%). Basal transcriptional levels addressed by RT-qPCR in control fish indicate that CTR1 and ATP7B was highly transcribed in liver of freshwater guppies while CTR1 was highly transcribed in gut of saltwater guppies. This could explain the higher Cu accumulation observed in liver of freshwater guppies and in gut of saltwater guppies, because CTR1 is involved in Cu uptake. Reduced gill mRNA expression of CTR1 was observed in freshwater guppies exposed to 20.0μg/L Cu and in saltwater guppies exposed to 5.0μg/L Cu. In turn, reduced mRNA expression of gut ATP7B was observed in freshwater and salt water guppies exposed to 9.0 and 20.0μg/L Cu. Liver CTR1 and ATP7B transcription were not affected by Cu exposure. These findings suggest that gill CTR1 and gut ATP7B are down-regulated to limit Cu absorption after exposure to dissolved Cu, while liver CTR1 and ATP7B levels are maintained to allow Cu storage and detoxification. In conclusion, findings reported here

  5. Polymeric micelles as a drug delivery system enhance cytotoxicity of vinorelbine through more intercellular accumulation.

    Science.gov (United States)

    Lu, Xiaoyan; Zhang, Fayun; Qin, Lei; Xiao, Fengying; Liang, Wei

    2010-05-01

    Polymeric micelles had been used as an efficacious carrier system for anti-cancer drug delivery. However, it is not clear whether the molecular mechanism of drug encapsulated in micelles is same as free drug. In this study, the mechanism of vinorelbine loaded in glycol-phosphatidylethanolamine (PEG-PE) micelles (M-Vino) on tumor cells was investigated. Compared with free vinorelbine (Free Vino), M-Vino was more effective in inhibiting the growth of tumor cells in vitro, inducing G(2)/M phase arrest and apoptosis of tumor cells. M-Vino showed a faster entry and higher accumulation in 4T1 cells than free vinorelbine. Therefore, M-Vino destabilized microtubules, induced cell death, and enhanced its cytotoxicity through more intercellular accumulation of vinorelbine.

  6. phoU inactivation in Pseudomonas aeruginosa enhances accumulation of ppGpp and polyphosphate.

    Science.gov (United States)

    de Almeida, Luiz Gustavo; Ortiz, Julia Helena; Schneider, René P; Spira, Beny

    2015-05-01

    Inorganic polyphosphate (polyP) is a linear polymer composed of several molecules of orthophosphate (Pi) linked by energy-rich phosphoanhydride bonds. In Pseudomonas aeruginosa, Pi is taken up by the ABC transporter Pst, encoded by an operon consisting of five genes. The first four genes encode proteins involved in the transport of Pi and the last gene of the operon, phoU, codes for a protein which exact function is unknown. We show here that the inactivation of phoU in P. aeruginosa enhanced Pi removal from the medium and polyP accumulation. The phoU mutant also accumulated high levels of the alarmone guanosine tetraphosphate (ppGpp), which in turn increased the buildup of polyP. In addition, phoU inactivation had several pleiotropic effects, such as reduced growth rate and yield and increased sensitivity to antibiotics and stresses. However, biofilm formation was not affected by the phoU mutation.

  7. The Or Gene Enhances Carotenoid Accumulation and Stability During Post-Harvest Storage of Potato Tubers

    Institute of Scientific and Technical Information of China (English)

    Li Li; Mark Failla; Theodore W.Thannhauser; Yong Yang; Qiang Xu; Katherine Owsiany; Ralf Welsch; Chureeporn Chitchumroonchokchai; Shan Lu; Joyce Van Eck; Xiu-Xin Deng

    2012-01-01

    Provitamin A carotenoids in staple crops are not very stable during storage and their loss compromises nutritional quality.To elucidate the fundamental mechanisms underlying carotenoid accumulation and stability,we investigated transgenic potato tubers that expressed the cauliflower Orange (Or) gene.We found that the Or transgene not only promoted retention of β-carotene level,but also continuously stimulated its accumulation during 5 months of cold storage.In contrast,no increased levels of carotenoids were observed in the tubers of vector-only controls or a yellowflesh variety during the same period of storage.The increased carotenoid accumulation was found to be associated with the formation of lipoprotein-carotenoid sequestering structures,as well as with the enhanced abundance of phytoene synthase,a key enzyme in the carotenoid biosynthetic pathway.Furthermore,the provitamin A carotenoids stored were shown to be stable during simulated digestion and accessible for uptake by human intestinal absorptive cells.Proteomic analysis identified three major functional groups of proteins (i.e.heat shock proteins,glutathione-S-transferases,and carbohydrate metabolic proteins) that are potentially important in the Or-regulated carotenoid accumulation.Our results show that regulation of carotenoid sequestration capacity is an important mechanism by which carotenoid stability is regulated.Our findings suggest that induction of a proper sink structure formation in staple crops may provide the crops with a unique ability to promote and/or stabilize provitamin A accumulation during plant growth and post-harvest storage.

  8. Ablative fractional laser enhances MAL-induced PpIX accumulation

    DEFF Research Database (Denmark)

    Haak, C S; Christiansen, K; Erlendsson, Andrés M

    2016-01-01

    BACKGROUND AND OBJECTIVES: Pretreatment of skin with ablative fractional laser enhances accumulation of topical provided photosensitizer, but essential information is lacking on the interaction between laser channel densities and pharmacokinetics. Hence our objectives were to investigate how prot...... by enhancing AFL densities up to 5%. Further, this model indicates that incubation time as well as drug concentration of MAL may be reduced with laser pretreatment....... protoporphyrin accumulation was affected by laser densities, incubation time and drug concentration. METHODS: We conducted the study on the back of healthy male volunteers (n=11). Test areas were pretreated with 2940nm ablative fractional Er:YAG laser, 11.2mJ per laser channel using densities of 1, 2, 5, 10...... incubation. The individual fluorescence intensity reached from the highest density (15%) and longest MAL 160mg/g incubation time (180min) was selected as reference (100%) for other interventional measurements. RESULTS: A low laser density of 1% markedly enhanced fluorescence intensities from 34% to 75% (no...

  9. Proteomic analyzes of copper metabolism in an in vitro model of Wilson disease using surface enhanced laser desorption/ionization-time of flight-mass spectrometry

    NARCIS (Netherlands)

    Roelofsen, H; Balgobind, R; Vonk, RJ

    2004-01-01

    In Wilson disease, mutations in the ATP7B-gene lead to hepatic accumulation of copper that becomes toxic when the hepatic binding capacity is exceeded, leading to oxidative stress and acute liver failure. Several proteins are probably involved in dealing with the excess copper and oxidative stress.

  10. A copper-catalyzed bioleaching process for enhancement of cobalt dissolution from spent lithium-ion batteries.

    Science.gov (United States)

    Zeng, Guisheng; Deng, Xiaorong; Luo, Shenglian; Luo, Xubiao; Zou, Jianping

    2012-01-15

    A copper-catalyzed bioleaching process was developed to recycle cobalt from spent lithium-ion batteries (mainly LiCoO(2)) in this paper. The influence of copper ions on bioleaching of LiCoO(2) by Acidithiobacillus ferrooxidans (A.f) was investigated. It was shown that almost all cobalt (99.9%) went into solution after being bioleached for 6 days in the presence of 0.75 g/L copper ions, while only 43.1% of cobalt dissolution was obtained after 10 days without copper ions. EDX, XRD and SEM analyses additionally confirmed that the cobalt dissolution from spent lithium-ion batteries could be improved in the presence of copper ions. The catalytic mechanism was investigated to explain the enhancement of cobalt dissolution by copper ions, in which LiCoO(2) underwent a cationic interchange reaction with copper ions to form CuCo(2)O(4) on the surface of the sample, which could be easily dissolved by Fe(3+).

  11. Clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: A large-scale field trial on heavily polluted soil

    Energy Technology Data Exchange (ETDEWEB)

    Castiglione, S. [Dipartimento di Biologia, Universita di Milano, Via Celoria 25, I-20100 Milano (Italy); Todeschini, V. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Franchin, C. [Dipartimento di Biologia e.s., Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Torrigiani, P. [Dipartimento di Colture Arboree, Universita di Bologna, Via Fanin 46, I-40127 Bologna (Italy); Gastaldi, D. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Cicatelli, A. [Dipartimento di Chimica, Universita di Salerno, Stecca 7, Via Ponte don Melillo, I-84084 Fisciano (Saudi Arabia) (Italy); Rinaudo, C.; Berta, G. [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy); Biondi, S. [Dipartimento di Biologia e.s., Universita di Bologna, Via Irnerio 42, I-40126 Bologna (Italy); Lingua, G., E-mail: guido.lingua@mfn.unipmn.i [Dipartimento di Scienze dell' Ambiente e della Vita, Universita del Piemonte Orientale, via Bellini 25/G, I-15100 Alessandria (Italy)

    2009-07-15

    Three ex situ collections of poplar clones from natural populations of Populus alba and P. nigra growing in northern Italy were assessed for their genetic dissimilarity (GD) by means of amplified fragment length polymorphism (AFLP). The high GD evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. After one growth season, clonal differences in plant survival and growth were observed. On the basis of performance, six clones were singled out, and used to evaluate copper and zinc accumulation in different organs. Clonal differences in metal concentrations were most evident for leaves and stems; one clone of P. alba (AL35) had a distinctly higher concentration of both metals in the roots. Leaf polyamine (putrescine, spermidine, spermine) profiles correlated with tissue metal concentrations, depending on the clone, plant organ and metal. In particular, the high metal-accumulating clone AL35 exhibited a dramatically higher concentration of free and conjugated putrescine. Overall, the results indicate that, given the high GD of Populus even within populations, it is possible to identify genotypes best suited for soil clean-up, and useful also for investigating physiological markers associated with high metal accumulation/tolerance - High survival rate and heavy metal accumulation are associated with high polyamine concentration in an elite poplar clone.

  12. Mercury bioaccumulation in the aquatic plant Elodea nuttallii in the field and in microcosm: accumulation in shoots from the water might involve copper transporters.

    Science.gov (United States)

    Regier, Nicole; Larras, Floriane; Bravo, Andrea Garcia; Ungureanu, Viorel-Gheorghe; Amouroux, David; Cosio, Claudia

    2013-01-01

    Previous studies suggest that macrophytes might participate in bioaccumulation and biomagnification of toxic mercury (Hg) in aquatic environment. Hg bioaccumulation and uptake mechanisms in macrophytes need therefore to be studied. Amongst several macrophytes collected in an Hg contaminated reservoir in Romania, Elodea nuttallii showed a high organic and inorganic Hg accumulation and was then further studied in the laboratory. Tolerance and accumulation of Hg of this plant was also high in the microcosm. Basipetal transport of inorganic Hg was predominant, whereas acropetal transport of methyl-Hg was observed with apparently negligible methylation or demethylation in planta. Hg concentrations were higher in roots>leaves>stems and in top>middle>bottom of shoots. In shoots, more than 60% Hg was found intracellularly where it is believed to be highly available to predators. Accumulation in shoots was highly reduced by cold, death and by competition with Cu(+). Hg in E. nuttallii shoots seems to mainly originate from the water column, but methyl-Hg could also be remobilized from the sediments and might drive in part its entry in the food web. At the cellular level, uptake of Hg into the cell sap of shoots seems linked to the metabolism and to copper transporters. The present work highlights an important breakthrough in our understanding of Hg accumulation and biomagnifications: the remobilization of methyl-Hg from sediments to aquatic plants and differences in uptake mechanisms of inorganic and methyl-Hg in a macrophyte.

  13. Synthesis of copper doped Zinc oxide nanowires with enhanced ultraviolet photoresponse behavior

    Science.gov (United States)

    Ghosh, S. P.; Das, K. C.; Tripathy, N.; Moharana, A.; Adhikari, A.; Bose, G.; Kim, D. H.; Lee, T. I.; Myoung, J. M.; Kar, J. P.

    2017-02-01

    This work mainly focused on the synthesis of copper doped zinc oxide nanowires by hydrothermal method, their characterization and their ultraviolet (UV) light sensing response at room temperature. The structural and morphological characterization was carried out using X-ray diffraction and scanning electron microscopy. Enhanced ultraviolet (UV) photodetection property has been achieved for a dopant concentration of 2.5wt% and 5wt% showing UV photosensitivity values (photo-to-dark current ratio) of around 800 and 1800, respectively. This is an order of magnitude higher than the undoped ZnO nanowires. High photocurrent gain is attributed to the trapping of carriers under dark and detrapping them under UV illumination by Cu-related defects. Enhancement in photosensitivity indicates that Cu-doped ZnO nanowires are promising candidates for UV photodetection applications.

  14. Enhanced non-enzymatic glucose sensing based on copper nanoparticles decorated nitrogen-doped graphene.

    Science.gov (United States)

    Jiang, Ding; Liu, Qian; Wang, Kun; Qian, Jing; Dong, Xiaoya; Yang, Zhenting; Du, Xiaojiao; Qiu, Baijing

    2014-04-15

    Copper nanoparticles (NPs) decorated nitrogen-doped graphene (Cu-N-G) was prepared by a facile thermal treatment, and further employed as a novel sensing material for fabricating the sensitive non-enzymatic glucose sensor. Compared with pure Cu NPs, the Cu-N-G showed enhanced electrocatalytic activity to glucose oxidation due to the integration of N-G, which exhibited the oxidation peak current of glucose ca. 23-fold higher than that of pure Cu NPs. The presented sensor showed excellent performances for glucose detection including wide linear range of 0.004-4.5 mM, low detection limit (1.3 μM, S/N=3), high sensitivity (48.13 μA mM(-1)), fast response time (graphene as enhanced materials in fabricating sensors for chemical and biochemical analysis.

  15. Copper: From neurotransmission to neuroproteostasis

    Directory of Open Access Journals (Sweden)

    Carlos M Opazo

    2014-07-01

    Full Text Available Copper is critical for the Central Nervous System (CNS development and function. In particular, different studies have shown the effect of copper at brain synapses, where it inhibits Long Term Potentation (LTP and receptor pharmacology. Paradoxically, according to recent studies copper is required for a normal LTP response. Copper is released at the synaptic cleft, where it blocks glutamate receptors, which explain its blocking effects on excitatory neurotransmission. Our results indicate that copper also enhances neurotransmission through the accumulation of PSD95 protein, which increase the levels of AMPA receptors located at the plasma membrane of the post-synaptic density. Thus, our findings represent a novel mechanism for the action of copper, which may have implications for the neurophysiology and neuropathology of the CNS. These data indicate that synaptic configuration is sensitive to transient changes in transition metal homeostasis. Our results suggest that copper increases GluA1 subunit levels of the AMPA receptor through the anchorage of AMPA receptors to the plasma membrane as a result of PSD-95 accumulation. Here, we will review the role of copper on neurotransmission of CNS neurons. In addition, we will discuss the potential mechanisms by which copper could modulate neuronal proteostasis (neuroproteostasis in the CNS with focus in the Ubiquitin Proteasome System, which is particularly relevant to neurological disorders such Alzheimer’s disease (AD where copper and protein dyshomeostasis may contribute to neurodegeneration. An understanding of these mechanisms may ultimately lead to the development of novel therapeutic approaches to control metal and synaptic alterations observed in AD patients.

  16. Copper-2 Hypothesis for Causation of the Current Alzheimer's Disease Epidemic Together with Dietary Changes That Enhance the Epidemic.

    Science.gov (United States)

    Brewer, George J

    2017-03-20

    is too high, a simple device can be put on the tap to remove copper. In addition to the copper-2 hypothesis, this review covers dietary changes that enhance the epidemic.

  17. Dependence of ablation threshold and LIPSS formation on copper thin films by accumulative UV picosecond laser shots

    Science.gov (United States)

    Huynh, Thi Trang Dai; Semmar, Nadjib

    2014-09-01

    The ablation threshold and Laser-induced periodic surface structure (LIPSS) formation on copper thin film were investigated using a picosecond laser (Nd:YAG laser: 266 nm, 42 ps, 10 Hz). We show that the ablation threshold varies with respect to the number of laser shots ( N) on two different substrates. The single-shot ablation threshold was estimated to be close to 170 ± 20 mJ/cm2. The incubation coefficient was estimated to be 0.68 ± 0.03 for copper thin films on silicon and glass substrates. In addition, morphology changes of the ablated regions, in the same spot area, were studied as a function of fluence and number of laser shots. An intermediate structure occurred with a mix of low spatial frequency LIPSS (LSFL), high spatial frequency LIPSS (HSFL) and regular spikes at a fluence F LIPSS formation was established in the form of a 2D map.

  18. Proline improves copper tolerance in chickpea (Cicer arietinum).

    Science.gov (United States)

    Singh, Vijeta; Bhatt, Indu; Aggarwal, Anjali; Tripathi, Bhumi Nath; Munjal, Ashok Kumar; Sharma, Vinay

    2010-09-01

    The present study suggests the involvement of proline in copper tolerance of four genotypes of Cicer arietinum (chickpea). Based on the data of tolerance index and lipid peroxidation, the order for copper tolerance was as follows: RSG 888 > CSG 144 > CSG 104 > RSG 44 in the selected genotypes. The basis of differential copper tolerance in chickpea genotypes was characterized by analyzing, antioxidant enzymes (superoxide dismutase, ascorbated peroxidase and catalase), phytochelatins, copper uptake, and proline accumulation. Chickpea genotypes showed stimulated superoxide dismutase activity at all tested concentrations of copper, but H(2)O(2) decomposing enzymes especially; ascorbate peroxidase did not increase with 25 and 50 microM copper treatments. Catalase activity, however, increased at lower copper concentrations but failed to stimulate at 50 microM copper. Such divergence in responses of these enzymes minimizes their importance in protecting chickpea against copper stress. The sensitive genotypes showed greater enhancement of phytochelatins than that of tolerant genotypes. Hence, the possibility of phytochelatins in improving copper tolerance in the test plant is also excluded. Interestingly, the order of proline accumulation in the chickpea genotypes (RSG 888 > CSG 144 > CSG 104 > RSG 44) was exactly similar to the order of copper tolerance. Based on hyperaccumulation of proline in tolerant genotype (RSG 44) and the reduction and improvement of lipid peroxidation and tolerance index, respectively, by proline pretreatment, we conclude that hyperaccumulation of proline improves the copper tolerance in chickpea.

  19. Pipecolic acid enhances resistance to bacterial infection and primes salicylic acid and nicotine accumulation in tobacco.

    Science.gov (United States)

    Vogel-Adghough, Drissia; Stahl, Elia; Návarová, Hana; Zeier, Juergen

    2013-11-01

    Distinct amino acid metabolic pathways constitute integral parts of the plant immune system. We have recently identified pipecolic acid (Pip), a lysine-derived non-protein amino acid, as a critical regulator of systemic acquired resistance (SAR) and basal immunity to bacterial infection in Arabidopsis thaliana. In Arabidopsis, Pip acts as an endogenous mediator of defense amplification and priming. For instance, Pip conditions plants for effective biosynthesis of the phenolic defense signal salicylic acid (SA), accumulation of the phytoalexin camalexin, and expression of defense-related genes. Here, we show that tobacco plants respond to leaf infection by the compatible bacterial pathogen Pseudomonas syringae pv tabaci (Pstb) with a significant accumulation of several amino acids, including Lys, branched-chain, aromatic, and amide group amino acids. Moreover, Pstb strongly triggers, alongside the biosynthesis of SA and increases in the defensive alkaloid nicotine, the production of the Lys catabolites Pip and α-aminoadipic acid. Exogenous application of Pip to tobacco plants provides significant protection to infection by adapted Pstb or by non-adapted, hypersensitive cell death-inducing P. syringae pv maculicola. Pip thereby primes tobacco for rapid and strong accumulation of SA and nicotine following bacterial infection. Thus, our study indicates that the role of Pip as an amplifier of immune responses is conserved between members of the rosid and asterid groups of eudicot plants and suggests a broad practical applicability for Pip as a natural enhancer of plant disease resistance.

  20. Enhanced arsenic accumulation by engineered yeast cells expressing Arabidopsis thaliana phytochelatin synthase.

    Science.gov (United States)

    Singh, Shailendra; Lee, Wonkyu; Dasilva, Nancy A; Mulchandani, Ashok; Chen, Wilfred

    2008-02-01

    Phytochelatins (PCs) are naturally occurring peptides with high-binding capabilities for a wide range of heavy metals including arsenic (As). PCs are enzymatically synthesized by phytochelatin synthases and contain a (gamma-Glu-Cys)(n) moiety terminated by a Gly residue that makes them relatively proteolysis resistant. In this study, PCs were introduced by expressing Arabidopsis thaliana Phytochelatin Synthase (AtPCS) in the yeast Saccharomyces cerevisiae for enhanced As accumulation and removal. PCs production in yeast resulted in six times higher As accumulation as compared to the control strain under a wide range of As concentrations. For the high-arsenic concentration, PCs production led to a substantial decrease in levels of PC precursors such as glutathione (GSH) and gamma-glutamyl cysteine (gamma-EC). The levels of As(III) accumulation were found to be similar between AtPCS-expressing wild type strain and AtPCS-expressing acr3Delta strain lacking the arsenic efflux system, suggesting that the arsenic uptake may become limiting. This is further supported by the roughly 1:3 stoichiometric ratio between arsenic and PC2 (n = 2) level (comparing with a theoretical value of 1:2), indicating an excess availability of PCs inside the cells. However, at lower As(III) concentration, PC production became limiting and an additive effect on arsenic accumulation was observed for strain lacking the efflux system. More importantly, even resting cells expressing AtPCS pre-cultured in Zn(2+) enriched media showed PCs production and two times higher arsenic removal than the control strain. These results open up the possibility of using cells expressing AtPCS as an inexpensive sorbent for the removal of toxic arsenic.

  1. Organic amendments enhance Pb tolerance and accumulation during micropropagation of Daphne jasminea.

    Science.gov (United States)

    Wiszniewska, Alina; Muszyńska, Ewa; Hanus-Fajerska, Ewa; Smoleń, Sylwester; Dziurka, Michał; Dziurka, Kinga

    2017-01-01

    The study investigated the effects of organic amendments: pineapple pulp (PP) and agar hydrolyzate (AH), on micropropagation and Pb bioaccumulation and tolerance in a woody shrub Daphne jasminea cultured in vitro. The amendments were analyzed for their content of carbohydrates, phenolic acids, and phytohormones and added at a dose of 10 mL L(-1) to the medium containing 1.0 mM lead nitrate. Micropropagation coefficient increased by 10.2-16.6 % in PP and AH variants, respectively. Growth tolerance index increased by 22.9-31.8 % for the shoots and by 60.1-82.4 % for the roots. In the absence of Pb, the additives inhibited multiplication and growth of microplantlets. PP and AH facilitated Pb accumulation in plant organs, especially in the roots. PP enhanced bioconcentration factor and AH improved Pb translocation to the shoots. Adaptation to Pb was associated with increased accumulation of phenolics and higher radical scavenging activity. Medium supplementation, particularly with AH, enhanced antiradical activity of Pb-adapted lines but reduced the content of phenolic compounds. The study results indicated that supplementation with organic amendments may be beneficial in in vitro selection against lead toxicity.

  2. Copper and cobalt mobility in soil and accumulation in a metallophyte as influenced by experimental manipulation of soil chemical factors.

    Science.gov (United States)

    Lange, Bastien; Pourret, Olivier; Meerts, Pierre; Jitaru, Petru; Cancès, Benjamin; Grison, Claude; Faucon, Michel-Pierre

    2016-03-01

    The influence of Fe oxides, Mn oxides and organic matter (OM) on the Cu and Co mobility in soil and accumulation in the metallophyte Anisopappus chinensis (Ac), as compared with Helianthus annuus (Ha), was experimentally investigated. Growth and accumulation response when increasing the exchangeable Cu and Co concentrations in soil were also investigated. Plants were cultivated on soil where concentrations of Cu, Co, Fe oxides, Mn oxides and OM content were varied according to 36 treatments. The OM supply decreased the Cu mobility and increased the Co mobility, resulting in decreasing the foliar Cu of Ac and increasing the foliar Co of Ha. The Fe oxides supply could increase the Cu accumulation for Ac, but was not verified for Ha. Compared with Ha, Ac increasingly accumulated Cu and Co without negative effect on plant growth while increasing Cu and Co mobility to phytotoxic concentrations. The results revealed promising perspectives for the use of Ac in Cu-contaminated environment phytoremediation applications.

  3. Two-step flash light sintering process for enhanced adhesion between copper complex ion/silane ink and a flexible substrate

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Eun-Beom; Joo, Sung-Jun [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Ahn, Heejoon [Department of Organic and Nano Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Kim, Hak-Sung, E-mail: kima@hanyang.ac.kr [Department of Mechanical Convergence Engineering, Hanyang University, Haengdang-dong, Seongdong-gu, Seoul 133-791 (Korea, Republic of); Institute of Nano Science and Technology, Hanyang University, Seoul 133-791 (Korea, Republic of)

    2016-03-31

    A copper complex ion ink (including copper nanoparticles, a copper precursor and a silane coupling agent) was synthesized to enhance the adhesion between the copper pattern and a polyimide (PI) substrate. Oxygen plasma treatment was performed on the polyimide substrate to initiate a chemical reaction between the complex ion ink and the polyimide. Then, a two-step flash light sintering method (consisting of preheating and main sintering) was used to sinter the copper complex ion ink. The copper complex ion patterns were characterized as a function of the weight fraction of silane coupling agent using scanning electron microscopy (SEM), a four-point probe method and adhesion testing. In addition, a bending fatigue test was performed to evaluate the reliability of the conductive copper pattern under cyclic bending. The copper pattern fabricated with copper complex ion ink containing 3 wt% silane coupling agent exhibited the highest adhesion level (5B), the lowest resistivity (7.6 μΩ·cm) and a low resistance change (18%) after the bending fatigue test. The two-step sintering method used to enhance the adhesion between the copper complex ion ink and polyimide substrate was also studied using X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FT-IR). - Highlights: • The copper complex ion ink with copper nanoparticles and copper precursor was fabricated. • The copper complex ion ink was sintered by two-step flash light sintering method. • The sintered copper pattern exhibited the highest adhesion level (5B). • The resistivity of sintered copper pattern was 7.6 μΩ·cm.

  4. Dispersion of chitosan on perlite for enhancement of copper(II) adsorption capacity.

    Science.gov (United States)

    Hasan, Shameem; Ghosh, Tushar K; Viswanath, Dabir S; Boddu, Veera M

    2008-04-01

    Chitosan coated perlite beads were prepared by drop-wise addition of slurry, made of chitosan dissolved in oxalic acid and perlite, to an alkaline bath (0.7 M NaOH). The beads that contained 32% chitosan enhanced the accessibility of OH and amine groups present in chitosan for adsorption of copper ions. The experiments using Cu(II) ions were carried out in the concentration range of 50-4100 mg/L (0.78-64.1 mmol/L). Adsorption capacity for Cu(II) was pH dependent and a maximum uptake of 104 mg/g of beads (325 mg/g of chitosan) was obtained at pH 4.5 when its equilibrium concentration in the solution was 812.5 mg/L at 298 K. The XPS and TEM data suggested that copper was mainly adsorbed as Cu(II) and was attached to amine groups. The adsorption data could be fitted to one-site Langmuir adsorption model. Anions in the solution had minimal effect on Cu(II) adsorption by chitosan coated perlite beads. EDTA was used effectively for the regeneration of the bed. The diffusion coefficient of Cu(II) onto chitosan coated beads was calculated from the breakthrough curve and was found to be 2.02 x 10(-8) cm(2)/s.

  5. Enhancing the copper(II) complexes cytotoxicity to cancer cells through bound to human serum albumin.

    Science.gov (United States)

    Gou, Yi; Zhang, Yao; Qi, Jinxu; Zhou, Zuping; Yang, Feng; Liang, Hong

    2015-03-01

    We use Schiff-base salicylaldehyde benzoylhydrazone (HL) as the ligand for copper(II), resulting in the complexes [CuCl(L)]·H2O (C1), [CuNO3(L)]·H2O (C2) and [CuBr(L)]2 (C3). We characterize the Cu(II) compounds' interactions with human serum albumin (HSA) using fluorescence spectroscopy and molecular docking. These studies revealed that Cu(II) compounds propensity bound to IIA subdomain of HSA possible by hydrophobic interactions and hydrogen bond. Cu(II) compounds produce intracellular reactive oxygen species (ROS) in cancer cells. Complexes of HSA and copper(II) compounds enhance about 2-fold cytotoxicity in cancer cells but do not raise cytotoxicity levels in normal cells in vitro. Compared with C3 alone, HSA-C3 complex promotes HepG2 cell apoptosis and has a stronger capacity to promote cell cycle arrest at the G2/M phase of HepG2.

  6. Sono-electroanalysis of copper: enhanced detection and determination in the presence of surfactants.

    Science.gov (United States)

    Hardcastle, Joanna Lorraine; Hignett, Geraldine; Melville, James L; Compton, Richard G

    2002-04-01

    Surfactant adsorption has been shown to have a passivating effect on the electrode surface during anodic stripping voltammetric measurements. In the present work the feasibility of sono-anodic stripping analysis for the determination of copper in aqueous media contaminated with surfactant has been studied at an unmodified bare glassy carbon electrode. We illustrate the deleterious effect of three common surfactants, sodium dodecyl sulfate (SDS), dodecyl pyridinium chloride (DPC) and Triton-X 100 (TX-100) on conventional electroanalysis. The analogous sono-electroanalytical response was investigated for each surfactant at ultrasound intensities above and below the cavitation threshold. The enhancement in the stripping signal observed is attributed to the increased mass transport due to acoustic streaming and above the cavitation threshold the intensity of cavitational events is significantly increased leading to shearing of adsorbed surfactant molecules from the surface. As a result accurate analyses for SDS concentrations up to 100 ppm are possible, with analytical signals visible in solutions of SDS and TX-100 of 1000 ppm. Analysis is reported in high concentration of surfactant with use of sono-solvent double extraction. The power of this technique is clearly illustrated by the ability to obtain accurate measurements of copper concentration from starting solutions containing 1000 ppm SDS or TX-100. This was also exemplified by analysis of the low concentration 0.3 microM Cu(II) solution giving a percentage recovery of 94% in the presence of 1000 ppm SDS or TX-100.

  7. Accumulation of copper in the kidney of pigs fed high dietary zinc is due to metallothionein expression with minor effects on genes involved in copper metabolism.

    Science.gov (United States)

    Zetzsche, A; Schunter, N; Zentek, J; Pieper, R

    2016-05-01

    A study was conducted to determine the effect of high dietary zinc (Zn) oxide on trace element accumulation in various organs with special emphasis on the kidney. A total of 40 weaned piglets were allocated into two groups with 16 and 24 piglets each receiving a diet containing normal (NZn; 100mg Zn/kg) or high (HZn; 2,100mg Zn/kg) Zn concentration, respectively. After two weeks, eight piglets from each treatment were killed and organ samples were taken. Eight piglets from the remaining 16 pigs fed HZn diets were changed to NZn diets (CZn). All remaining piglets were killed after another two weeks for organ sampling. Trace element concentration was determined in the jejunum, liver, kidney, pancreas, bone (metacarpal IV), spleen, lung, thymus, tonsils and lymph nodes of jejunum, ileum and colon. Kidney mRNA expression of Zn transporter ZnT1 and ZIP4, genes involved in Cu metabolism (Ctr1, Atox1, SOD1, ATP7A, CCS, CP) and divalent metal ion transport (DMT1) and binding (MT-1a, MT-2b, MT-3) were determined. The Zn concentration in jejunum, liver, pancreas tissue and metacarpal IV was higher (Pkidney. No significant differences for Cu chaperones, Cu transporters and Cu-dependent factors were determined despite decreased expression of Atox1 after two weeks and increased Ctr1 expression over time in the HZn group. Expression of MT-1a, MT-2b and MT-3 were significantly higher in HZn fed pigs with most pronounced effects for MT-1a > MT-2b > MT-3. Gene expression of MTs in pigs fed CZn diets did not differ from pigs fed NZn diets. The data suggest that high dietary Zn feeding in pigs leads to Cu co-accumulation in the kidney of pigs with minor effect on genes relevant for Cu metabolism. In addition, the organ Zn and Cu accumulation is reversible after two weeks of withdrawal of high dietary Zn.

  8. Clonal differences in survival capacity, copper and zinc accumulation, and correlation with leaf polyamine levels in poplar: a large-scale field trial on heavily polluted soil.

    Science.gov (United States)

    Castiglione, S; Todeschini, V; Franchin, C; Torrigiani, P; Gastaldi, D; Cicatelli, A; Rinaudo, C; Berta, G; Biondi, S; Lingua, G

    2009-07-01

    Three ex situ collections of poplar clones from natural populations of Populus alba and P. nigra growing in northern Italy were assessed for their genetic dissimilarity (GD) by means of amplified fragment length polymorphism (AFLP). The high GD evidenced within populations was exploited for screening 168 clones in a field trial on heavy metal-polluted soil. After one growth season, clonal differences in plant survival and growth were observed. On the basis of performance, six clones were singled out, and used to evaluate copper and zinc accumulation in different organs. Clonal differences in metal concentrations were most evident for leaves and stems; one clone of P. alba (AL35) had a distinctly higher concentration of both metals in the roots. Leaf polyamine (putrescine, spermidine, spermine) profiles correlated with tissue metal concentrations, depending on the clone, plant organ and metal. In particular, the high metal-accumulating clone AL35 exhibited a dramatically higher concentration of free and conjugated putrescine. Overall, the results indicate that, given the high GD of Populus even within populations, it is possible to identify genotypes best suited for soil clean-up, and useful also for investigating physiological markers associated with high metal accumulation/tolerance.

  9. Enhanced decomposition offsets enhanced productivity and soil carbon accumulation in coastal wetlands responding to climate change (Invited)

    Science.gov (United States)

    Kirwan, M. L.; Blum, L. K.

    2010-12-01

    Where coastal wetlands are sediment deficient, ecosystem persistence depends on the balance between organic matter production and decay. Recent work in tidal wetlands suggests that elevated CO2 and temperature warming will increase plant growth, organic matter accumulation, and the ability of marshes to survive sea level rise. However, we find that decomposition rates also increase by about 12% per degree C of warming. Our measured temperature response is greater than most terrestrial studies, twice as high as the response of salt marsh productivity to temperature warming, and roughly equivalent to the productivity response associated with elevated CO2 in C3 marsh plants. Therefore, our results suggest that enhanced CO2 and warmer temperatures will actually make marshes less resilient to sea level rise, and tend to promote a release of soil carbon. Elevated temperatures tend to increase rates of sea level rise more than any acceleration in organic matter accumulation, suggesting the possibility of a positive feedback between climate, sea level rise, and carbon emissions in coastal environments.

  10. Plasma-enhanced chemical vapor deposition of graphene on copper substrates

    Directory of Open Access Journals (Sweden)

    Nicolas Woehrl

    2014-04-01

    Full Text Available A plasma enhanced vapor deposition process is used to synthesize graphene from a hydrogen/methane gas mixture on copper samples. The graphene samples were transferred onto SiO2 substrates and characterized by Raman spectroscopic mapping and atomic force microscope topographical mapping. Analysis of the Raman bands shows that the deposited graphene is clearly SLG and that the sheets are deposited on large areas of several mm2. The defect density in the graphene sheets is calculated using Raman measurements and the influence of the process pressure on the defect density is measured. Furthermore the origin of these defects is discussed with respect to the process parameters and hence the plasma environment.

  11. Enhancement of absorption in vertically-oriented graphene sheets growing on a thin copper layer

    Science.gov (United States)

    Rozouvan, Tamara; Poperenko, Leonid; Kravets, Vasyl; Shaykevich, Igor

    2017-02-01

    The optical properties and surface structure of graphene films grown on thin copper Cu (1 μm) layer using chemical vapour deposition method were investigated via spectroscopic ellipsometry and nanoscopic measurements. Angle variable ellipsometry measurements were performed to analyze the features of dispersion of the complex refractive index and optical conductivity. It was observed significant enhancement of the absorption band in the vertically-oriented graphene sheets layer with respect to the bulk graphite due to interaction between excited localized surface plasmon at surface of thin Cu layer and graphene's electrons. Scanning tunneling microscopy measurements with atomic spatial resolution revealed vertical crystal lattice structure of the deposited graphene layer. The obtained results provide direct evidence of the strong influence of the growing condition and morphology of nanostructure on electronic and optical behaviours of graphene film.

  12. Electrodeposited Reduced Graphene Oxide Films on Stainless Steel, Copper, and Aluminum for Corrosion Protection Enhancement

    Directory of Open Access Journals (Sweden)

    Abdulkareem Mohammed Ali Al-Sammarraie

    2017-01-01

    Full Text Available The enhancement of corrosion protection of metals and alloys by coating with simple, low cost, and highly adhered layer is still a main goal of many workers. In this research graphite flakes converted into graphene oxide using modified Hammers method and then reduced graphene oxide was electrodeposited on stainless steel 316, copper, and aluminum for corrosion protection application in seawater at four temperatures, namely, 20, 30, 40, and 50°C. All corrosion measurements, kinetics, and thermodynamics parameters were established from Tafel plots using three-electrode potentiostat. The deposited films were examined by FTIR, Raman, XRD, SEM, and AFM techniques; they revealed high percentages of conversion to the few layers of graphene with confirmed defects.

  13. Surface-enhanced Raman scattering of patterned copper nanostructure electrolessly plated on arrayed nanoporous silicon pillars.

    Science.gov (United States)

    Jiang, Wei Fen; Shan, Wen Wen; Ling, Hong; Wang, Yu Sheng; Cao, Yan Xia; Li, Xin Jian

    2010-10-20

    A new synthesized composite structure, a patterned copper/silicon nanoporous pillar array (Cu/Si-NPA) made by depositing Cu on Si-NPA using an immersion plating method, can be used as a surface-enhanced Raman scattering (SERS) substrate. Its surface component and morphology were analyzed by x-ray diffraction and field-emission scanning electron microscopy, respectively. It was found that the surface was Cu with two kinds of crystal structures: a continuous film composed of Cu nanocrystallites covering the Si-NPA, and a quasi-regular, interconnected network composed of loop-chains of Cu crystallites, with the size in the range of several tens of nanometer to 300 nm, surrounding the porous Si pillars. The composite structure is strongly SERS active using rhodamine 6G as probe molecules, which is mainly due to the patterned hierarchical Cu structure. © 2010 IOP Publishing Ltd

  14. Surface-Enhanced Resonance Raman Scattering and Visible Extinction Spectroscopy of Copper Chlorophyllin: An Upper Level Chemistry Experiment

    Science.gov (United States)

    Schnitzer, Cheryl S.; Reim, Candace Lawson; Sirois, John J.; House, Paul G.

    2010-01-01

    Advanced chemistry students are introduced to surface-enhanced resonance Raman scattering (SERRS) by studying how sodium copper chlorophyllin (CuChl) adsorbs onto silver colloids (CuChl/Ag) as a function of pH. Using both SERRS and visible extinction spectroscopy, the extent of CuChl adsorption and colloidal aggregation are monitored. Initially at…

  15. Surface-Enhanced Resonance Raman Scattering and Visible Extinction Spectroscopy of Copper Chlorophyllin: An Upper Level Chemistry Experiment

    Science.gov (United States)

    Schnitzer, Cheryl S.; Reim, Candace Lawson; Sirois, John J.; House, Paul G.

    2010-01-01

    Advanced chemistry students are introduced to surface-enhanced resonance Raman scattering (SERRS) by studying how sodium copper chlorophyllin (CuChl) adsorbs onto silver colloids (CuChl/Ag) as a function of pH. Using both SERRS and visible extinction spectroscopy, the extent of CuChl adsorption and colloidal aggregation are monitored. Initially at…

  16. Enantioseparation of Amino Acids by Micelle-Enhanced Ultrafiltration : Experimental and Theoretical Studies of Copper(II) Amino Acid Interactions

    NARCIS (Netherlands)

    Bruin, de T.J.M.

    2000-01-01

    A micelle-enhanced ultrafiltration system, which can potentially be used for large scale separations, has been used to investigate the resolution of amino acid enantiomers. For this purpose amino acid derivatives were synthesized, which in combination with copper(II) ions were used as chiral selecto

  17. Gate field plate IGBT with trench accumulation layer for extreme injection enhancement

    Science.gov (United States)

    Xu, Xiaorui; Chen, Wanjun; Liu, Chao; Chen, Nan; Tao, Hong; Shi, Yijun; Ma, Yinchang; Zhou, Qi; Zhang, Bo

    2017-04-01

    A gate field plate IGBT (GFP-IGBT) with extreme injection enhancement is proposed and verified using TCAD simulations. The GFP-IGBT features a gate field plate (GFP) inserted into n-drift region directly and a tiny P-base region separated from the GFP. In the ON-state, the accumulation layer is formed near to not only the bottom but also the side of the trench, which enhances electron injection efficiency. And the tiny P-base region reduces the holes extracted by reverse-biased P-base/N-drift junction. Both the GFP and tiny P-base contribute to achieving extreme injection enhancement, leading to a low forward voltage drop. In the OFF-state, due to the low stored charges in N-buffer layer, GFP-IGBT shows a short current fall time, leading to a decrease of turn-off loss. The simulation results show that, compared with the conventional IGBT, the GFP-IGBT offers a forward voltage drop reduction of 25% or current fall time reduction of 89% (i.e. turn-off loss reduction of 53%), resulting in low power loss. The excellent device performance, coupled with a commercial IGBT-compatible fabrication process, makes the proposed GFP-IGBT a promising candidate for power switching applications.

  18. Artificial breakwaters as garbage bins: Structural complexity enhances anthropogenic litter accumulation in marine intertidal habitats.

    Science.gov (United States)

    Aguilera, Moisés A; Broitman, Bernardo R; Thiel, Martin

    2016-07-01

    Coastal urban infrastructures are proliferating across the world, but knowledge about their emergent impacts is still limited. Here, we provide evidence that urban artificial reefs have a high potential to accumulate the diverse forms of litter originating from anthropogenic activities around cities. We test the hypothesis that the structural complexity of urban breakwaters, when compared with adjacent natural rocky intertidal habitats, is a driver of anthropogenic litter accumulation. We determined litter abundances at seven sites (cities) and estimated the structural complexity in both urban breakwaters and adjacent natural habitats from northern to central Chile, spanning a latitudinal gradient of ∼15° (18°S to 33°S). Anthropogenic litter density was significantly higher in coastal breakwaters when compared to natural habitats (∼15.1 items m(-2) on artificial reefs versus 7.4 items m(-2) in natural habitats) at all study sites, a pattern that was temporally persistent. Different litter categories were more abundant on the artificial reefs than in natural habitats, with local human population density and breakwater extension contributing to increase the probabilities of litter occurrence by ∼10%. In addition, structural complexity was about two-fold higher on artificial reefs, with anthropogenic litter density being highest at intermediate levels of structural complexity. Therefore, the spatial structure characteristic of artificial reefs seems to enhance anthropogenic litter accumulation, also leading to higher residence time and degradation potential. Our study highlights the interaction between coastal urban habitat modification by establishment of artificial reefs, and pollution. This emergent phenomenon is an important issue to be considered in future management plans and the engineering of coastal ecosystems.

  19. Hydrophytes lack potential to exhibit cadmium stress induced enhancement in lipid peroxidation and accumulation of proline

    Energy Technology Data Exchange (ETDEWEB)

    Dhir, Bhupinder; Sharmila, P.; Saradhi, P. Pardha

    2004-02-10

    Investigations were carried out to evaluate if hydrophytes (viz. Ceratophyllum, Wolffia, and Hydrilla) can be used as markers to assess the level of heavy metal pollution in aquatic bodies. The potential of these hydrophytes for lipid peroxidation and accumulation of proline in response to cadmium (Cd{sup 2+}) pollution was studied. Hydrophytes were raised in artificial pond water (APW) supplemented with various levels of Cd{sup 2+}. Interestingly, unlike mesophytes none of the hydrophytes showed ability to accumulate proline. Infact, in response to Cd{sup 2+} pollution hydrophytes exhibited a decline in proline levels in comparison to controls but mesophytes (viz. Brassica juncea, Vigna radiata and Triticum aestivum) showed progressive increase in the level of proline with increase in the extent of Cd{sup 2+} pollution. Mesophytes showed six to nine-fold increase in the level of proline in response to 1 mM Cd{sup 2+}. The potential of the above hydrophytes for lipid peroxidation was also low under Cd{sup 2+} stress. In contrast, as expected a significant enhancement in the lipid peroxidation was observed in all three mesophytes in response to their exposure to Cd{sup 2+}. About two-fold increase in production of malondialdehyde (a cytotoxic product of lipid peroxidation) was recorded in mesophytes exposed to 1 mM Cd{sup 2+}. However, a decline in chlorophyll (Chl a and Chl b) levels was recorded in response to Cd{sup 2+}pollution both in hydrophytes as well as mesophytes. In summary, hydrophytes neither have potential to accumulate proline nor have ability to accelerate lipid peroxidation under heavy metal stress. This suggests that the adaptive mechanism(s) existing in hydrophytes to tackle heavy metal stress is distinct from that in mesophytes.

  20. Root ABA Accumulation Enhances Rice Seedling Drought Tolerance under Ammonium Supply: Interaction with Aquaporins

    Science.gov (United States)

    Ding, Lei; Li, Yingrui; Wang, Ying; Gao, Limin; Wang, Min; Chaumont, François; Shen, Qirong; Guo, Shiwei

    2016-01-01

    In previous studies, we demonstrated that ammonium nutrition enhances the drought tolerance of rice seedlings compared to nitrate nutrition and contributes to a higher root water uptake ability. It remains unclear why rice seedlings maintain a higher water uptake ability when supplied with ammonium under drought stress. Here, we focused on the effects of nitrogen form and drought stress on root abscisic acid (ABA) concentration and aquaporin expression using hydroponics experiments and stimulating drought stress with 10% PEG6000. Drought stress decreased the leaf photosynthetic rate and stomatal conductivity and increased the leaf temperature of plants supplied with either ammonium or nitrate, but especially under nitrate supply. After 4 h of PEG treatment, the root protoplast water permeability and the expression of root PIP and TIP genes decreased in plants supplied with ammonium or nitrate. After 24 h of PEG treatment, the root hydraulic conductivity, the protoplast water permeability, and the expression of some aquaporin genes increased in plants supplied with ammonium compared to those under non-PEG treatment. Root ABA accumulation was induced by 24 h of PEG treatment, especially in plants supplied with ammonium. The addition of exogenous ABA decreased the expression of PIP and TIP genes under non-PEG treatment but increased the expression of some of them under PEG treatment. We concluded that drought stress induced a down-regulation of aquaporin expression, which appeared earlier than did root ABA accumulation. With continued drought stress, aquaporin expression and activity increased due to root ABA accumulation in plants supplied with ammonium. PMID:27559341

  1. Fuzzy, copper-based multi-functional composite particles serving simultaneous catalytic and signal-enhancing roles

    Science.gov (United States)

    Li, Xiangming; Hu, Yingmo; An, Qi; Luan, Xinglong; Zhang, Qian; Zhang, Yihe

    2016-04-01

    Multifunctional plasmonic particles serving simultaneously as catalysts and label-free reporting agents are highly pursued due to their great potential in enhancing reaction operational efficiencies. Copper is an abundant and economic resource, and it possesses practical applicability in industries, but no dual-functional copper-based catalytic and self-reporting particles have been reported so far. This study proposes a facile strategy to prepare high-performance dual-functional copper-based composite particles that catalyze reactions and simultaneously serve as a SERS (surface enhanced Raman spectra) active, label-free reporting agent. Polyelectrolyte-modified reduced graphene oxide particles are used as the reactive precursors in the fabrication method. Upon adding Cu(NO3)2 solutions into the precursor dispersions, composite particles comprised by copper/copper oxide core and polyelectrolyte-graphene shell were facilely obtained under sonication. The as-prepared composite particles efficiently catalyzed the conversion of 4-nitrophenol to 4-aminophenol and simultaneously acted as the SERS-active substrate to give enhanced Raman spectra of the produced 4-aminophenol. Taking advantage of the assembling capabilities of polyelectrolyte shells, the composite particles could be further assembled onto a planar substrate to catalyze organic reactions, facilitating their application in various conditions. We expect this report to promote the fabrication and application of copper-based multifunctional particles.Multifunctional plasmonic particles serving simultaneously as catalysts and label-free reporting agents are highly pursued due to their great potential in enhancing reaction operational efficiencies. Copper is an abundant and economic resource, and it possesses practical applicability in industries, but no dual-functional copper-based catalytic and self-reporting particles have been reported so far. This study proposes a facile strategy to prepare high

  2. Monitoring intracellular polyphosphate accumulation in enhanced biological phosphorus removal systems by quantitative image analysis.

    Science.gov (United States)

    Mesquita, Daniela P; Amaral, A Luís; Leal, Cristiano; Carvalheira, Mónica; Cunha, Jorge R; Oehmen, Adrian; Reis, Maria A M; Ferreira, Eugénio C

    2014-01-01

    A rapid methodology for intracellular storage polyphosphate (poly-P) identification and monitoring in enhanced biological phosphorus removal (EBPR) systems is proposed based on quantitative image analysis (QIA). In EBPR systems, 4',6-diamidino-2-phenylindole (DAPI) is usually combined with fluorescence in situ hybridization to evaluate the microbial community. The proposed monitoring technique is based on a QIA procedure specifically developed for determining poly-P inclusions within a biomass suspension using solely DAPI by epifluorescence microscopy. Due to contradictory literature regarding DAPI concentrations used for poly-P detection, the present work assessed the optimal DAPI concentration for samples acquired at the end of the EBPR aerobic stage when the accumulation occurred. Digital images were then acquired and processed by means of image processing and analysis. A correlation was found between average poly-P intensity values and the analytical determination. The proposed methodology can be seen as a promising alternative procedure for quantifying intracellular poly-P accumulation in a faster and less labour-intensive way.

  3. Enhanced Cadmium Accumulation in Transgenic Tobacco Expressing the Phytochelatin Synthase Gene of Cynodon dactylon L.

    Institute of Scientific and Technical Information of China (English)

    Jiangchuan Li; Jiangbo Guo; Wenzhong Xu; Mi Ma

    2006-01-01

    Bermudagrass (Cynodon dactylon L. cv. Goldensun) is highly resistant to and accumulates large amounts of cadmium (Cd). A phytochelatin synthase (PCS) cDNA (CdPCS1) was isolated from this grass by rapid amplification of cDNA ends. The putative CdPCS1 protein shared a high homology with PCS from other plants, with 79% homology at the N-terminal and 47% homology at the C-terminal. However, 16 Cys residues were found at the C-terminal of CdPCS1, and among these residues, three positions were different from other PCS proteins. Semiquantitative reverse transcription-polymerase chain reaction analysis showed that Cd stress induced CdPCS1 expression in both roots and leaves in Bermudagrass. We verified that CdPCS1 plays an important role in Cd tolerance in yeast cells by expressing the gene in ABDE1, a Cd-sensitive mutant. CdPCS1 was then introduced into tobacco plants. The phytochelatin level in some transgenic tobacco lines increased 3.88-fold more than in wild type plants and Cd accumulation in these transgenic plants was enhanced 3.21-fold accordingly. The results suggested that CdPCS1 could be used as a gene element for phytoremediation in the future.

  4. A heavy metal P-type ATPase OsHMA4 prevents copper accumulation in rice grain

    Science.gov (United States)

    As one of the most important staple crops, rice not only provides more than one fifth of daily calories for half of the world’s human population but is also a major source of mineral nutrients. However, little is known about the genetic basis of mineral nutrient accumulation in rice grain such as co...

  5. Accumulation of arsenic, lead, copper, and zinc, and synthesis of phytochelatins by indigenous plants of a mining impacted area.

    Science.gov (United States)

    Machado-Estrada, Blenda; Calderón, Jaqueline; Moreno-Sánchez, Rafael; Rodríguez-Zavala, José S

    2013-06-01

    Several native plants, able to grow in an unconfined mining impacted area that is now in close vicinity with urban areas, were evaluated for their ability to accumulate heavy metals. The main soil contaminants were As, Pb, Cu, and Zn. Sampling of the rhizospheric metal polluted soil showed that Euphorbia prostrata Aiton, Parthenium incanum Kunth, and Zinnia acerosa (DC.) A. Gray were able to grow in the presence of high amounts of mixtures of these elements. The plants accumulated the metals in the above ground parts and increased the synthesis of thiol molecules. E. prostrata showed the highest capacity for accumulation of the mixture of elements (588 μg g DW(-1)). Analysis of the thiol-molecules profile showed that these plants synthesized high amounts of long-chain phytochelatins, accompanied by low amounts of monothiol molecules, which may be related to their higher resistance to As and heavy metals. The three plants showed translocation factors from roots to leaves >1 for As, Pb, Cu, and Zn. Thus, by periodically removing aerial parts, these plants could be useful for the phytoremediation of semi-arid and arid mining impacted areas, in which metal hyper-accumulator plants are not able to grow.

  6. Numerical simulation of fluid flow and heat transfer in enhanced copper tube

    Science.gov (United States)

    Rahman, M. M.; Zhen, T.; Kadir, A. K.

    2013-06-01

    Inner grooved tube is enhanced with grooves by increasing the inner surface area. Due to its high efficiency of heat transfer, it is used widely in power generation, air conditioning and many other applications. Heat exchanger is one of the example that uses inner grooved tube to enhance rate heat transfer. Precision in production of inner grooved copper tube is very important because it affects the tube's performance due to various tube parameters. Therefore, it is necessary to carry out analysis in optimizing tube performance prior to production in order to avoid unnecessary loss. The analysis can be carried out either through experimentation or numerical simulation. However, experimental study is too costly and takes longer time in gathering necessary information. Therefore, numerical simulation is conducted instead of experimental research. Firstly, the model of inner grooved tube was generated using SOLIDWORKS. Then it was imported into GAMBIT for healing, followed by meshing, boundary types and zones settings. Next, simulation was done in FLUENT where all the boundary conditions are set. The simulation results were observed and compared with published experimental results. It showed that heat transfer enhancement in range of 649.66% to 917.22% of inner grooved tube compared to plain tube.

  7. Electron accumulation on metal nanoparticles in plasmon-enhanced organic solar cells.

    Science.gov (United States)

    Salvador, Michael; MacLeod, Bradley A; Hess, Angela; Kulkarni, Abhishek P; Munechika, Keiko; Chen, Jennifer I L; Ginger, David S

    2012-11-27

    Plasmonic metal nanoparticles have been used to enhance the performance of thin-film devices such as organic photovoltaics based on polymer/fullerene blends. We show that silver nanoprisms accumulate long-lived negative charges when they are in contact with a photoexcited bulk heterojunction blend composed of poly(3-hexylthiophene)/phenyl-C61-butyric acid methyl ester (P3HT/PCBM). We report both the charge modulation and electroabsorption spectra of silver nanoprisms in solid-state devices and compare these spectra with the photoinduced absorption spectra of P3HT/PCBM blends containing silver nanoprisms. We assign a previously unidentified peak in the photoinduced absorption spectra to the presence of photoinduced electrons on the silver nanoprisms. We show that coating the nanoprisms with a 2.5 nm thick insulating layer can completely inhibit this charging. These results may inform methods for limiting metal-mediated losses in plasmonic solar cells.

  8. Lysosome dysfunction enhances oxidative stress-induced apoptosis through ubiquitinated protein accumulation in Hela cells.

    Science.gov (United States)

    Yu, Chunyan; Huang, Xiaowei; Xu, Ye; Li, Hongyan; Su, Jing; Zhong, Jiateng; Kang, Jinsong; Liu, Yuhe; Sun, Liankun

    2013-01-01

    The role of lysosomal system in oxidative stress-induced apoptosis in cancer cells is not fully understood. Menadione is frequently used as oxidative stress model. It is indicated that menadione could induce autophagy in Hela cells. In the present study, we examined whether the lysosomal inhibitor, ammonium chloride (NH(4)Cl) could prevent the autophagy flux by inhibiting the fusion of autophagosomes with lysosomes and enhance apoptosis induced by menadione via mitochondrial pathway. The results demonstrated generation and accumulation of reactive oxygen species and increased levels of ubiquitinated proteins and GRP78 in cells treated with both menadione and NH(4)Cl. Our data indicates that lysosomal system through autophagy plays an important role in preventing menadione-induced apoptosis in Hela cells by clearing misfolded proteins, which alleviates endoplasmic reticulum stress.

  9. Copper-induced oxidative stress in maize shoots (Zea mays L.): H2O2 accumulation and peroxidases modulation.

    Science.gov (United States)

    Bouazizi, Houda; Jouili, H; El Ferjani, E

    2007-06-01

    The effect of copper excess on growth, H2O2 level and peroxidase activities were studied in maize shoots. Ten-day-old seedlings were cultured in nutrient solution that contained Cu2+ ions at various concentrations (50 and 100 microM) for seven days. High concentrations of Cu2+ ions caused significant decrease both in matter production and elongation of maize shoots. In addition, treatment with CuSO4 increased levels of H2O2 and induced changes in several peroxidase activities. Moreover, the disturbance of the physiological parameters was accompanied by the modulation of the peroxidase activities: GPX (Guaiacol peroxidase, EC 1.11.1.7), CAPX (Coniferyl alcohol peroxidase, EC 1.11.1.4) and APX (Ascorbate peroxidase, EC. 1.11.1.11). Furthermore, this modulation becomes highly significant, especially, in the presence of 100 microM of CuSO4.

  10. Hybrid Copper-Silver Conductive Tracks for Enhanced Oxidation Resistance under Flash Light Sintering.

    Science.gov (United States)

    Yim, Changyong; Sandwell, Allen; Park, Simon S

    2016-08-31

    We developed a simple method to prepare hybrid copper-silver conductive tracks under flash light sintering. The developed metal nanoparticle-based ink is convenient because its preparation process is free of any tedious washing steps. The inks were composed of commercially available copper nanoparticles which were mixed with formic acid, silver nitrate, and diethylene glycol. The role of formic acid is to remove the native copper oxide layer on the surface of the copper nanoparticles. In this way, it facilitates the formation of a silver outer shell on the surface of the copper nanoparticles through a galvanic replacement. In the presence of formic acid, the copper nanoparticles formed copper formate, which was present in the unsintered tracks. However, under illumination by a xenon flash light, the copper formate was then converted to copper. Moreover, the resistance of the copper-only films increased by 6 orders of magnitude when oxidized at high temperatures (∼220 °C). However, addition of silver nitrate to the inks suppressed the oxidation of the hybrid copper-silver films, and the resistance changes in these inks at high temperatures were greatly reduced. In addition, the hybrid inks proved to be advantageous for use in electrical circuits as they demonstrated a stable electrical conductivity after exposure to ambient air at 180 °C.

  11. Accumulation of cadmium, zinc, and copper by Helianthus annuus L.: impact on plant growth and uptake of nutritional elements.

    Science.gov (United States)

    Rivelli, Anna Rita; De Maria, Susanna; Puschenreiter, Markus; Gherbin, Piergiorgio

    2012-04-01

    We investigated the effects on physiological response, trace elements and nutrients accumulation of sunflower plants grown in soil contaminated with: 5 mg kg(-1) of Cd; 5 and 300 mg kg(-1) of Cd and Zn, respectively; 5, 300, and 400 mg kg(-1) of Cd, Zn, and Cu, respectively. Contaminants applied did not produce large effects on growth, except in Cd-Zn-Cu treatment in which leaf area and total dry matter were reduced, by 15%. The contamination with Cd alone did not affect neither growth nor physiological parameters, despite considerable amounts of Cd accumulated in roots and older leaves, with a high bioconcentration factor from soil to plant. By adding Zn and then Cu to Cd in soil, significant were the toxic effects on chlorophyll content and water relations due to greater accumulation of trace elements in tissues, with imbalances in nutrients uptake. Highly significant was the interaction between shoot elements concentration (Cd, Zn, Cu, Fe, Mg, K, Ca) and treatments. Heavy metals concentrations in roots always exceeded those in stem and leaves, with a lower translocation from roots to shoots, suggesting a strategy of sunflower to compartmentalise the potentially toxic elements in physiologically less active parts in order to preserve younger tissues.

  12. GmCLC1 Confers Enhanced Salt Tolerance through Regulating Chloride Accumulation in Soybean

    Directory of Open Access Journals (Sweden)

    Peipei Wei

    2016-07-01

    Full Text Available The family of chloride channel proteins that mediate Cl- transportation play vital roles in plant nutrient supply, cellular action potential and turgor pressure adjustment, stomatal movement, hormone signal recognition and transduction, Cl- homeostasis, and abiotic and biotic stress tolerance. The anionic toxicity, mainly caused by chloride ions (Cl-, on plants under salt stress remains poorly understood. In this work, we investigated the function of soybean Cl-/H+ antiporter GmCLC1 under salt stress in transgenic Arabidopsis thaliana, soybean, and yeast. We found that GmCLC1 enhanced salt tolerance in transgenic A. thaliana by reducing the Cl- accumulation in shoots and hence released the negative impact of salt stress on plant growth. Overexpression of GmCLC1 in the hairy roots of soybean sequestered more Cl- in their roots and transferred less Cl- to their shoots, leading to lower relative electrolyte leakage values in the roots and leaves. When either the soybean GmCLC1 or the yeast chloride transporter gene, GEF1, was transformed into the yeast gef1 mutant, and then treated with different chloride salts (MnCl2, KCl, NaCl, enhanced survival rate was observed. The result indicates that GmCLC1 and GEF1 exerted similar effects on alleviating the stress of diverse chloride salts on the yeast gef1 mutant. Together, this work suggests a protective function of GmCLC1 under Cl- stress.

  13. Upon exposure to Cu nanoparticles, accumulation of copper in the isopod Porcellio scaber is due to the dissolved Cu ions inside the digestive tract.

    Science.gov (United States)

    Golobič, Miha; Jemec, Anita; Drobne, Damjana; Romih, Tea; Kasemets, Kaja; Kahru, Anne

    2012-11-06

    The fate of nanoparticles in organisms is of significant interest. In the current work, we used a test system with terrestrial isopods (Porcellio scaber) fed with food spiked with Cu NPs or soluble Cu salt for 14 days. Two different doses were used for spiking to yield final concentrations of 2000 and 5000 μg Cu/g dry food. After the exposure period, part of the exposed group of animals was transferred to clean food to depurate. Cu content was analyzed in the digestive glands, gut, and the 'rest' of the body. Similar patterns of (i) assimilated and depurated amounts of Cu, (ii) Cu body distribution, and (iii) effect on isopods feeding behavior were observed regardless of whether the animals were fed with Cu NPs or soluble Cu salt spiked food. Thus, Cu ions and not Cu NPs were assimilated by the digestive gland cells. Solubilization of the Cu NPs applied to the leaves was also analyzed with chemical methods and recombinant Cu-sensing bacteria. The comparison of the in vitro data on solubilization of Cu NPs and in vivo data on Cu accumulation in the animal tissues showed that about 99% of accumulated copper ions was dissolved from ingested Cu NPs in the digestive system of isopods.

  14. Fluorinated copper phthalocyanine nanowires for enhancing interfacial electron transport in organic solar cells.

    Science.gov (United States)

    Yoon, Seok Min; Lou, Sylvia J; Loser, Stephen; Smith, Jeremy; Chen, Lin X; Facchetti, Antonio; Marks, Tobin J; Marks, Tobin

    2012-12-12

    Zinc oxide is a promising candidate as an interfacial layer (IFL) in inverted organic photovoltaic (OPV) cells due to the n-type semiconducting properties as well as chemical and environmental stability. Such ZnO layers collect electrons at the transparent electrode, typically indium tin oxide (ITO). However, the significant resistivity of ZnO IFLs and an energetic mismatch between the ZnO and the ITO layers hinder optimum charge collection. Here we report that inserting nanoscopic copper hexadecafluorophthalocyanine (F(16)CuPc) layers, as thin films or nanowires, between the ITO anode and the ZnO IFL increases OPV performance by enhancing interfacial electron transport. In inverted P3HT:PC(61)BM cells, insertion of F(16)CuPc nanowires increases the short circuit current density (J(sc)) versus cells with only ZnO layers, yielding an enhanced power conversion efficiency (PCE) of ∼3.6% vs ∼3.0% for a control without the nanowire layer. Similar effects are observed for inverted PTB7:PC(71)BM cells where the PCE is increased from 8.1% to 8.6%. X-ray scattering, optical, and electrical measurements indicate that the performance enhancement is ascribable to both favorable alignment of the nanowire π-π stacking axes parallel to the photocurrent flow and to the increased interfacial layer-active layer contact area. These findings identify a promising strategy to enhance inverted OPV performance by inserting anisotropic nanostructures with π-π stacking aligned in the photocurrent flow direction.

  15. Enhancing the Electrochemical Behavior of Pure Copper by Cyclic Potentiodynamic Passivation: A Comparison between Coarse- and Nano-Grained Pure Copper

    Science.gov (United States)

    Fattah-alhosseini, Arash; Imantalab, Omid; Attarzadeh, Farid Reza

    2016-10-01

    Electrochemical behavior of coarse- and nano-grained pure copper were modified and improved to a large extent by the application of cyclic potentiodynamic passivation. The efficacy of this method was evaluated on the basis of grain size which is of great importance in corrosion studies. In this study, the eight passes of accumulative roll bonding process at room temperature were successfully performed to produce nano-grained pure copper. Transmission electron microscopy image indicated that the average grain size reached below 100 nm after eight passes. On the basis of cyclic voltammetry and also the electrochemical tests performed after that, it was revealed that cyclic potentiodynamic passivation had a significant improving effect on the passive behavior of both coarse- and nano-grained samples. In addition, a superior behavior of nano-grained sample in comparison to coarse-grained one was distinguished by its smaller cyclic voltammogram loops, nobler free potentials, larger capacitive arcs in the Nyquist plots, and less charge carrier densities within the passive film.

  16. Interaction of brassinosteroids and polyamines enhances copper stress tolerance in raphanus sativus.

    Science.gov (United States)

    Choudhary, Sikander Pal; Oral, H Volkan; Bhardwaj, Renu; Yu, Jing-Quan; Tran, Lam-Son Phan

    2012-09-01

    Brassinosteroids (BRs) and polyamines (PAs) regulate various responses to abiotic stress, but their involvement in the regulation of copper (Cu) homeostasis in plants exposed to toxic levels of Cu is poorly understood. This study provides an analysis of the effects of exogenously applied BRs and PAs on radish (Raphanus sativus) plants exposed to toxic concentrations of Cu. The interaction of 24-epibrassinolide (EBR, an active BR) and spermidine (Spd, an active PA) on gene expression and the physiology of radish plants resulted in enhanced tolerance to Cu stress. Results indicated that the combined application of EBR and Spd modulated the expression of genes encoding PA enzymes and genes that impact the metabolism of indole-3-acetic acid (IAA) and abscisic acid (ABA) resulting in enhanced Cu stress tolerance. Altered expression of genes implicated in Cu homeostasis appeared to be the main effect of EBR and Spd leading to Cu stress alleviation in radish. Ion leakage, in vivo imaging of H(2)O(2), comet assay, and improved tolerance of Cu-sensitive yeast strains provided further evidence for the ability of EBR and Spd to improve Cu tolerance significantly. The study indicates that co-application of EBR and Spd is an effective approach for Cu detoxification and the maintenance of Cu homeostasis in plants. Therefore, the use of these compounds in agricultural production systems should be explored.

  17. Heat transfer enhancement through PCM thermal storage by use of copper fins

    Directory of Open Access Journals (Sweden)

    Rudonja Nedžad R.

    2016-01-01

    Full Text Available Enhancement of heat transfer over a cylinder shaped thermal energy storage filled by paraffin E53 by use of radial rectangular copper fins was analyzed. The thermo-physical features of the storage material are determined in separate experiments and implemented to Fluent software over UDF. Advanced thermal storage geometry comprehension and optimization required introduction of a parameter suitable for the analysis of heat transfer enhancement, so the ratio of heat transfer surfaces as a factor was proposed and applied. It is revealed that increase of the ratio of heat transfer surfaces leads to the decrease of melting time and vice versa. Numerical analysis, employing the 3D model built in Ansys software, observed storage reservoir geometries with variable number of longitudinal radial fins. The adjusted set of boundary conditions was carried out and both written in C language and implemented over UDF in order to define variable heat flux along the height of the heater. The comparison of acquired numerical and experimental results showed a strong correlation. Experimental validation of numerical results was done on the real TES apparatus. [Projekat Ministarstva nauke Republike Srbije, br. III42011, TR 33042 i OI 176006

  18. Screening of chelating ligands to enhance mercury accumulation from historically mercury-contaminated soils for phytoextraction.

    Science.gov (United States)

    Wang, Jianxu; Xia, Jicheng; Feng, Xinbin

    2017-01-15

    ligand for phytoextraction due to its great potential to enhance Hg accumulation in plants while decreasing bioavailable Hg concentration in the soil.

  19. ,* Copper transport and accumulation in spruce stems (picea abies(L.) Karsten) revelaed by laser-induced breakdown spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Krajcarova, Dr. Lucie [Czech Technical University; Novotny, Dr. Karel [Mendel University of Brno; Babula, Dr. Petr [Czech Technical University; Pravaznik, Dr Ivo [Czech Technical University; Kucerova, Dr. Petra [Czech Technical University; Vojtech, Dr. Adam [Czech Technical University; Martin, Madhavi Z [ORNL; Kizek, Dr. Rene [Czech Technical University; Kaiser, Jozef [ORNL

    2013-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) in double pulse configuration (DP LIBS) was used for scanning elemental spatial distribution in annual terminal stems of spruce (Picea abies (L.) Karsten). Cross sections of stems cultivated in Cu2+ solution of different concentrations were prepared and analyzed by DP LIBS. Raster scanning with 150 m spatial resolution was set and 2D (2-dimentional) maps of Cu and Ca distribution were created on the basis of the data obtained. Stem parts originating in the vicinity of the implementation of the cross sections were mineralized and subsequently Cu and Ca contents were analyzed by inductively coupled plasma mass spectrometry (ICP-MS). The results provide quantitative information about overall concentration of the elements in places, where LIBS measurements were performed. The fluorescence pictures were created to compare LIBS distribution maps and the fluorescence intensity (or the increase in autofluorescence) was used for the comparison of ICP-MS quantitative results. Results from these three methods can be utilized for quantitative measurements of copper ions transport in different plant compartments in dependence on the concentration of cultivation medium and/or the time of cultivation.

  20. Tumor-derived IL-35 promotes tumor growth by enhancing myeloid cell accumulation and angiogenesis.

    Science.gov (United States)

    Wang, Zhihui; Liu, Jin-Qing; Liu, Zhenzhen; Shen, Rulong; Zhang, Guoqiang; Xu, Jianping; Basu, Sujit; Feng, Youmei; Bai, Xue-Feng

    2013-03-01

    IL-35 is a member of the IL-12 family of cytokines that is comprised of an IL-12 p35 subunit and an IL-12 p40-related protein subunit, EBV-induced gene 3 (EBI3). IL-35 functions through IL-35R and has a potent immune-suppressive activity. Although IL-35 was demonstrated to be produced by regulatory T cells, gene-expression analysis revealed that it is likely to have a wider distribution, including expression in cancer cells. In this study, we demonstrated that IL-35 is produced in human cancer tissues, such as large B cell lymphoma, nasopharyngeal carcinoma, and melanoma. To determine the roles of tumor-derived IL-35 in tumorigenesis and tumor immunity, we generated IL-35-producing plasmacytoma J558 and B16 melanoma cells and observed that the expression of IL-35 in cancer cells does not affect their growth and survival in vitro, but it stimulates tumorigenesis in both immune-competent and Rag1/2-deficient mice. Tumor-derived IL-35 increases CD11b(+)Gr1(+) myeloid cell accumulation in the tumor microenvironment and, thereby, promotes tumor angiogenesis. In immune-competent mice, spontaneous CTL responses to tumors are diminished. IL-35 does not directly inhibit tumor Ag-specific CD8(+) T cell activation, differentiation, and effector functions. However, IL-35-treated cancer cells had increased expression of gp130 and reduced sensitivity to CTL destruction. Thus, our study indicates novel functions for IL-35 in promoting tumor growth via the enhancement of myeloid cell accumulation, tumor angiogenesis, and suppression of tumor immunity.

  1. Enhanced reactivity of dinuclear Copper(I) acetylides in dipolar cycloadditions

    DEFF Research Database (Denmark)

    Ahlquist, Mårten Sten Gösta; Fokin, V.V.

    2007-01-01

    Dinuclear alkynyl copper(I) complexes exhibit superior reactivity toward organic azides compared to their monomeric analogues. DFT studies indicate that the second copper center facilitates the formation of the cupracycle in the rate-determining step and stabilizes the metallacycle intermediate...... itself. These findings support the experimentally determined rate law and shed light on the origin of high reactivity of the in situ generated copper acetylides....

  2. Genotypic and environmental variation in cadmium, chromium, lead and copper in rice and approaches for reducing the accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Cao, Fangbin; Wang, Runfeng [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Cheng, Wangda [Jiaxing Academy of Agricultural Sciences, Jiaxing 314016 (China); Zeng, Fanrong; Ahmed, Imrul Mosaddek; Hu, Xinna; Zhang, Guoping [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China); Wu, Feibo, E-mail: wufeibo@zju.edu.cn [Institute of Crop Science, Department of Agronomy, College of Agriculture and Biotechnology, Zijingang Campus, Zhejiang University, Hangzhou 310058 (China)

    2014-10-15

    The field scale trials revealed significant genotypic and environmental differences in grain heavy metal (HM) concentrations of 158 newly developed rice varieties grown in twelve locations of Zhejiang province of China. Grain Pb and Cd contents in 5.3% and 0.4% samples, respectively, were above the maximum permissible concentration (MPC); none of samples had Cr/Cu exceeding MPC. Stepwise multiple linear regression analysis estimated soil HM critical levels for safe rice production. Low grain HM accumulation cultivars such as Xiushui817, Jiayou08-1 and Chunyou689 were recommended as suitable cultivars for planting in slight/medium HM contaminated soils. The alleviating regulator (AR) of (NH{sub 4}){sub 2}SO{sub 4} as N fertilizer coupled with foliar spray of a mixture containing glutathione (GSH), Si, Zn and Se significantly decreased grain Cd, Cr, Cu and Pb concentrations grown in HM contaminated fields with no effect on yield, indicating a promising measurement for further reducing grain HM content to guarantee safe food production. - Highlights: • Field trials evaluated situation of grain HM in main rice growing areas of Zhejiang. • Forecasting index system to predict rice grain HM concentration was achieved. • Hybrid rice holds higher grain Cd concentration than conventional cultivars. • Low grain HM accumulation rice cultivars were successfully identified. • Developed alleviating regulator which effectively reduced grain toxic HM.

  3. Early genotoxic response and accumulation induced by waterborne copper, lead, and arsenic in European seabass, Dicentrarchus labrax.

    Science.gov (United States)

    Canalejo, Antonio; Diaz-de-Alba, Margarita; Granado-Castro, M Dolores; Cordoba, Francisco; Espada-Bellido, Estrella; Galindo-Riaño, M Dolores; Torronteras, Rafael

    2016-02-01

    Cu, Pb, and As, which are among the most abundant metals in the aquatic environment, are also among the most health-threatened by causing diverse cellular injuries. The aim of this study was to assess and compare the potential early induction of genotoxic effects after waterborne Cu, Pb, and As exposure in European seabass, Dicentrarchus labrax, a commercial widely cultured fish, using the micronucleus (MN) assay in peripheral blood erythrocytes. Fish were exposed under laboratory conditions to nominal solutions ranging 0-10 mg/L for 24 and 96 h. Furthermore, actual metal ion concentrations were measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES) or differential pulse anodic stripping voltammetry (DPASV) in water and four fish tissues differentially related to environmental exposition and metal accumulation, i.e. the gills, liver, muscle, and brain. Dose-dependent increases of micronuclei (MNi) frequency were observed after these very short exposures; based on measured metal concentrations in water, the genotoxic effect ordered as Cu > As > Pb. Significant genotoxic effect at 0.009 mg/L Cu, 0.57 mg/L Pb, and 0.01 mg/L As was seen. For Cu and Pb these are only slightly higher, but for As it is notably lower than the USEPA criteria of maximum concentration to prevent acute toxicity in aquatic organisms. Furthermore, genotoxicity was differentially related to metal accumulation. MNi frequency correlated positively with the content of Pb in all the organs, with the content of As in liver and gills and only with the content of Cu in the brain. In conclusion, our findings raised environmental concerns because these depicted a genotoxic potential of Cu, Pb, and As after a very short exposure to low but environmentally relevant concentrations, too close to regulatory thresholds. In addition, the MN test in D. labrax could be considered an early biomarker of genotoxicity induced by these metals in fish.

  4. Joint enhancement of lead accumulation in Brassica plants by EDTA and ammonium sulfate in sand culture

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    When EDTA was added alone in the Pb-contaminated sand, the plant biomass and the total Pb amount in plant decreased in both species, Brassica pekinensis and B. juncea var. multiceps, though the shoot Pb amount increased. In contrast, when (NH4)2 SO4 was added alone in the Pb-contaminated sand, little effect was observed on the shoot Pb amount, though the root Pb amount was significantly increased in B. juncea var. multiceps. When amending EDTA and (NH4)2SO4 in combination, however, the shoot Pb amount in both species substantially increased, being, on an average, 2 times and 9 times higher than that in EDTA alone or (NH4)2 SO4 alone amended treatment, respectively.The two amendments showed antagonism for plant growth, but synergism for Pb bioaccumulation. B. pekinensis showed its highest level of shoot and total Pb amount in the treatment amended with EDTA and (NH4)2 SO4 only a half as much as in the other treatments. It is inferred that the mechanisms responsible for the joint-enhanced Pb accumulation might be concerned with the acidification of the growth medium, cation exchange reaction and relieving EDTA induced toxicity as results by amending ammonium sulfate.

  5. Formation of parkin aggregates and enhanced PINK1 accumulation during the pathogenesis of Parkinson's disease.

    Science.gov (United States)

    Um, Ji Won; Park, Hyun Jung; Song, Jihwan; Jeon, Iksoo; Lee, Gwang; Lee, Phil Hyu; Chung, Kwang Chul

    2010-03-19

    Parkinson's disease (PD) is a devastating neurodegenerative disease characterized by a distinct set of motor symptoms. Loss-of-function mutations in PTEN-induced kinase 1 (PINK1) or parkin have been linked to early-onset autosomal recessive forms of familial PD. We have recently shown that parkin (an E3 ubiquitin ligase) and PINK1 (a serine/threonine kinase) affect one other's stability, solubility, and tendency to form cytoprotective aggresomes (Um et al., 2009). Here we validated the functional relevance of this mutual interaction under pathologic PD conditions, by investigating the changes of expression and solubility of these factors in response to PD-linked toxins. Consistent with our previous cell culture data, exposure of human dopaminergic neuroblastoma SH-SY5Y cells to PD-linked toxins (1-methyl-4-phenylpyridinium ion, 6-hydroxydopamine, or MG132) reduced Nonidet P-40-soluble parkin levels and induced PINK1 accumulation. Consistent with our previous findings from parkin knockout mice, rat models of PD (6-hydroxydopamine-, rotenone-, or MG132-induced PD) were also associated with an increase in soluble and insoluble PINK1 levels as well as enhanced formation of parkin aggregates. These findings suggest that both PINK1 and parkin play important roles in regulating the formation of Lewy bodies during the pathogenesis of sporadic and familial PD.

  6. Criticality-Enhanced Magnetocaloric Effect in Quantum Spin Chain Material Copper Nitrate

    Science.gov (United States)

    Xiang, Jun-Sen; Chen, Cong; Li, Wei; Sheng, Xian-Lei; Su, Na; Cheng, Zhao-Hua; Chen, Qiang; Chen, Zi-Yu

    2017-01-01

    In this work, a systematic study of Cu(NO3)2·2.5 H2O (copper nitrate hemipentahydrate, CN), an alternating Heisenberg antiferromagnetic chain model material, is performed with multi-technique approach including thermal tensor network (TTN) simulations, first-principles calculations, as well as magnetization measurements. Employing a cutting-edge TTN method developed in the present work, we verify the couplings J = 5.13 K, α = 0.23(1) and Landé factors g∥= 2.31, g⊥ = 2.14 in CN, with which the magnetothermal properties have been fitted strikingly well. Based on first-principles calculations, we reveal explicitly the spin chain scenario in CN by displaying the calculated electron density distributions, from which the distinct superexchange paths are visualized. On top of that, we investigated the magnetocaloric effect (MCE) in CN by calculating its isentropes and magnetic Grüneisen parameter. Prominent quantum criticality-enhanced MCE was uncovered near both critical fields of intermediate strengths as 2.87 and 4.08 T, respectively. We propose that CN is potentially a very promising quantum critical coolant. PMID:28294147

  7. Handling of Copper and Copper Oxide Nanoparticles by Astrocytes.

    Science.gov (United States)

    Bulcke, Felix; Dringen, Ralf

    2016-02-01

    Copper is an essential trace element for many important cellular functions. However, excess of copper can impair cellular functions by copper-induced oxidative stress. In brain, astrocytes are considered to play a prominent role in the copper homeostasis. In this short review we summarise the current knowledge on the molecular mechanisms which are involved in the handling of copper by astrocytes. Cultured astrocytes efficiently take up copper ions predominantly by the copper transporter Ctr1 and the divalent metal transporter DMT1. In addition, copper oxide nanoparticles are rapidly accumulated by astrocytes via endocytosis. Cultured astrocytes tolerate moderate increases in intracellular copper contents very well. However, if a given threshold of cellular copper content is exceeded after exposure to copper, accelerated production of reactive oxygen species and compromised cell viability are observed. Upon exposure to sub-toxic concentrations of copper ions or copper oxide nanoparticles, astrocytes increase their copper storage capacity by upregulating the cellular contents of glutathione and metallothioneins. In addition, cultured astrocytes have the capacity to export copper ions which is likely to involve the copper ATPase 7A. The ability of astrocytes to efficiently accumulate, store and export copper ions suggests that astrocytes have a key role in the distribution of copper in brain. Impairment of this astrocytic function may be involved in diseases which are connected with disturbances in brain copper metabolism.

  8. Enhanced fatty acid accumulation in Isochrysis galbana by inhibition of the mitochondrial alternative oxidase pathway under nitrogen deprivation.

    Science.gov (United States)

    Zhang, Litao; Liu, Jianguo

    2016-07-01

    The purpose of this study was to clarify the interrelation between the mitochondrial alternative oxidase (AOX) pathway and fatty acid accumulation in marine microalga Isochrysis galbana. Under normal conditions, the activity of the AOX pathway was maintained at a low level in I. galbana. Compared with the normal condition, nitrogen deprivation significantly increased the AOX pathway activity and fatty acid accumulation. Under nitrogen deprivation, the inhibition of the AOX pathway by salicylhydroxamic acid caused the accumulation of reducing equivalents and the over-reduction of chloroplasts in I. galbana cells, leading to a decrease in the photosynthetic O2 evolution rate. The over-production of reducing equivalents due to the inhibition of the AOX pathway under nitrogen deprivation further enhanced the accumulation of fatty acids in I. galbana cells.

  9. Does Dietary Copper Supplementation enhance or diminish PCB126 Toxicity in Rodent Liver?

    Science.gov (United States)

    Lai, Ian K.; Klaren, William D.; Li, Miao; Wels, Brian; Simmons, Donald L.; Olivier, Alicia K.; Haschek, Wanda M.; Wang, Kai; Ludewig, Gabriele; Robertson, Larry W.

    2013-01-01

    Copper is essential for the function of the mitochondrial electron transport chain and several antioxidant proteins. However, in its free form copper can participate in Fenton-like reactions that produce reactive hydroxyl radicals. Aryl-hydrocarbon receptor (AhR) agonists, including the most potent polychlorinated biphenyl (PCB) congener, 3,3',4,4',5-pentachlorobiphenyl (PCB126), increase copper levels in rodent livers. This is accompanied by biochemical and toxic changes. To assess the involvement of copper in PCB toxicity, male Sprague Dawley rats were fed an AIN-93G diet with differing dietary copper levels: low (2 ppm), adequate (6 ppm), and high (10 ppm). After three weeks, rats from each group were given a single ip injection of corn oil (control), 1, or 5 μmol/kg body weight PCB126. Two weeks following injections, biochemical and morphological markers of hepatic toxicity, trace metal status, and hepatic gene expression of metalloproteins were evaluated. Increasing dietary copper was associated with elevated tissue levels of copper and ceruloplasmin. In the livers of PCB126-treated rats the hallmark signs of AhR activation were present, including increased cytochrome P-450 and lipid levels, and decreased glutathione. In addition a doubling of hepatic copper levels was seen and overall metals homeostasis was disturbed, resulting in decreased hepatic selenium, manganese, zinc and iron. Expression of key metalloproteins was either decreased (cytochrome c oxidase), unchanged (ceruloplasmin and CuZnSOD) or increased (tyrosinase, metallothionein 1 and 2) with exposure to PCB126. Increases in metallothionein may contribute/reflect the increased copper seen. Alterations in dietary copper did not amplify or abrogate the hepatic toxicity of PCB126. PCB126 toxicity, i.e. oxidative stress and steatosis, is clearly associated with disturbed metals homeostasis. Understanding the mechanisms of this disturbance may provide tools to prevent liver toxicity by other Ah

  10. Copper, nickel and zinc accumulations in lettuce grown in soil amended with contaminated cattle manure vermicompost after sequential cultivations.

    Science.gov (United States)

    Jordão, Cláudio P; de Andrade, Renato P; Cotta, Aloísio J B; Cecon, Paulo R; Neves, Júlio C L; Fontes, Mauricio P F; Fernandes, Raphael B A

    2013-01-01

    The Cu, Ni and Zn accumulations in leaves and roots of lettuce (Lactuca sativa L) grown in soil amended with natural and contaminated cattle manure vermicompost were evaluated. The vermicompost residues containing relatively high metal concentrations used in this work were obtained from a previous experiment, in which vermicompost was applied to removing metals from electroplating wastes. Sequential lettuce cultivations were conducted in pots containing the residual substrates from the first cultivation by adding metal-enriched vermicompost residues. In general, the Cu, Ni and Zn concentrations in leaves and roots of lettuce plants grown in vermicompost enriched with these metals were higher than in the treatment using the natural vermicompost. The metal concentrations in leaves from treatments with natural vermicompost were below the critical concentrations of toxicity to plants. However, the metal concentrations in leaves of the third cultivation in which metal-enriched vermicompost was applied were greater than the upper limit that causes plant toxicity, but no visual damage was observed in the plants. Treatment with Zn-enriched vermicompost resulted in toxicity symptoms, but plant damage did not result in the death of the plant. The chemical fractionation of Cu, Ni and Zn in residues from lettuce cultivation was evaluated by using a sequential extraction procedure and metal concentrations were increased in the different chemical fractions according to the increase of vermicompost dose.

  11. Purity-enhanced bulk synthesis of thin single-wall carbon nanotubes using iron-copper catalysts

    Science.gov (United States)

    Lim, H. E.; Miyata, Y.; Nakayama, T.; Chen, S.; Kitaura, R.; Shinohara, H.

    2011-09-01

    We report high purity and high yield synthesis of single-wall carbon nanotubes (SWCNTs) of narrow diameter from iron-copper bimetal catalysts. The SWCNTs with diameter of 0.8-1.2 nm are synthesized using the zeolite-supported alcohol chemical vapour deposition method. Single metal and bimetal catalysts are systematically investigated to achieve both the enhancement of SWCNT yield and the suppression of the undesired formation of graphitic impurities. The relative yield and purity of SWCNTs are quantified using optical absorption spectroscopy with an ultracentrifuge-based purification technique. For the single metal catalyst, iron shows the highest catalytic activity compared with the other metals such as cobalt, nickel, molybdenum, copper, and platinum. It has been found that the addition of copper to iron results in the suppression of carbonaceous impurity formation without decreasing the SWCNT yield. The purity-enhanced SWCNT shows fairly low sheet resistance due to the improvement of inter-nanotube contacts. This scalable design of SWCNT synthesis with enhanced purity is therefore a promising tool for shaping future high performance devices.

  12. Enhanced Heavy Metal Tolerance and Accumulation by Transgenic Sugar Beets Expressing Streptococcus thermophilus StGCS-GS in the Presence of Cd, Zn and Cu Alone or in Combination.

    Directory of Open Access Journals (Sweden)

    Dali Liu

    Full Text Available Phytoremediation is a promising means of ameliorating heavy metal pollution through the use of transgenic plants as artificial hyperaccumulators. A novel Streptococcus thermophilus γ-glutamylcysteine synthetase-glutathione synthetase (StGCS-GS that synthesizes glutathione (GSH with limited feedback inhibition was overexpressed in sugar beet (Beta vulgaris L., yielding three transgenic lines (s2, s4 and s5 with enhanced tolerance to different concentrations of cadmium, zinc and copper, as indicated by their increased biomass, root length and relative growth compared with wild-type plants. Transgenic sugar beets accumulated more Cd, Zn and Cu ions in shoots than wild-type, as well as higher GSH and phytochelatin (PC levels under different heavy metal stresses. This enhanced heavy metal tolerance and increased accumulation were likely due to the increased expression of StGCS-GS and consequent overproduction of both GSH and PC. Furthermore, when multiple heavy metal ions were present at the same time, transgenic sugar beets overexpressing StGCS-GS resisted two or three of the metal combinations (50 μM Cd-Zn, Cd-Cu, Zn-Cu and Cd-Zn-Cu, with greater absorption in shoots. Additionally, there was no obvious competition between metals. Overall, the results demonstrate the explicit role of StGCS-GS in enhancing Cd, Zn and Cu tolerance and accumulation in transgenic sugar beet, which may represent a highly promising new tool for phytoremediation.

  13. Enhanced Heavy Metal Tolerance and Accumulation by Transgenic Sugar Beets Expressing Streptococcus thermophilus StGCS-GS in the Presence of Cd, Zn and Cu Alone or in Combination.

    Science.gov (United States)

    Liu, Dali; An, Zhigang; Mao, Zijun; Ma, Longbiao; Lu, Zhenqiang

    2015-01-01

    Phytoremediation is a promising means of ameliorating heavy metal pollution through the use of transgenic plants as artificial hyperaccumulators. A novel Streptococcus thermophilus γ-glutamylcysteine synthetase-glutathione synthetase (StGCS-GS) that synthesizes glutathione (GSH) with limited feedback inhibition was overexpressed in sugar beet (Beta vulgaris L.), yielding three transgenic lines (s2, s4 and s5) with enhanced tolerance to different concentrations of cadmium, zinc and copper, as indicated by their increased biomass, root length and relative growth compared with wild-type plants. Transgenic sugar beets accumulated more Cd, Zn and Cu ions in shoots than wild-type, as well as higher GSH and phytochelatin (PC) levels under different heavy metal stresses. This enhanced heavy metal tolerance and increased accumulation were likely due to the increased expression of StGCS-GS and consequent overproduction of both GSH and PC. Furthermore, when multiple heavy metal ions were present at the same time, transgenic sugar beets overexpressing StGCS-GS resisted two or three of the metal combinations (50 μM Cd-Zn, Cd-Cu, Zn-Cu and Cd-Zn-Cu), with greater absorption in shoots. Additionally, there was no obvious competition between metals. Overall, the results demonstrate the explicit role of StGCS-GS in enhancing Cd, Zn and Cu tolerance and accumulation in transgenic sugar beet, which may represent a highly promising new tool for phytoremediation.

  14. Enhanced reactive adsorption of hydrogen sulfide on the composites of graphene/graphite oxide with copper (hydr)oxychlorides.

    Science.gov (United States)

    Mabayoje, Oluwaniyi; Seredych, Mykola; Bandosz, Teresa J

    2012-06-27

    Composites of copper (hydr)oxychlorides with graphite oxide or graphene were synthesized and used as adsorbents of hydrogen sulfide at dynamic conditions at ambient temperatures. The materials were extensively characterized before and after adsorption in order to link their performance to the surface features. X-ray diffraction, FTIR, thermal analysis, TEM, SEM/EDX, and adsorption of nitrogen were used. It was found that the composite with graphene has the most favorable surface features enhancing reactive adsorption of hydrogen sulfide. The presence of moisture in the H2S stream has a positive effect on the removal process owing to the dissociation process. H2S is retained on the surface via a direct replacement of OH groups and via acid-base reactions with the copper (hydr)oxide. Highly dispersed reduced copper species on the surface of the composite with graphene enhance activation of oxygen and cause formation of sulfites and sulfates. Higher conductivity of the graphene phase than that of graphite oxide helps in electron transfer in redox reactions.

  15. Extra Copper-mediated Enhancement of the DNA Cleavage Activity Supported with Wild-type Cu, Zn Superoxide Dismutase

    Institute of Scientific and Technical Information of China (English)

    ZHOU Ruo-Yu; JIANG Wei; ZHANG Li-Na; WANG Li; LIU Chang-Lin

    2008-01-01

    It is well known that the primary function of wild type Cu, Zn superoxide dismutase (holo SOD) is to catalyze the conversion of the superoxide anion to H2O2 and O2 as an antioxidant enzyme. However, the aberrant copper-mediated oxidation chemistry in the enzyme (including its mutation forms) that damages nucleic acids, proteins including itself and cell membrane has attracted extensive attention in the past decade. The present study examined the hydrogen peroxide-dependent DNA cleavage activity supported with the combinations between holo SOD and extra copper (holo SOD+nCu(Ⅱ)). The results indicate that the presence of extra copper can enhance the DNA cleavage activity and a cooperative effect between holo SOD and the extra Cu(Ⅱ) occurs in DNA cleavage. The relative activity and kinetic assay showed that the DNA cleavage activity of holo SOD+nCu(Ⅱ) was enhanced upon addition of extra Cu(Ⅱ). The favorable pH regions for the DNA cleavage were observed to be 3.6-5.6 and 9.0-10, suggesting the species responsible for the DNA cleavage are different in different pH regions. In addition,to obtain an insight into DNA cleavage pathways, the effect of free radical scavengers and inhibitors on the DNA cleavage activity was probed.

  16. Inhibitory effect of Piper betel leaf extracts on copper-mediated LDL oxidation and oxLDL-induced lipid accumulation via inducing reverse cholesterol transport in macrophages.

    Science.gov (United States)

    Ma, Gwo-Chin; Wu, Pei-Fang; Tseng, Hsien-Chun; Chyau, Charng-Cherng; Lu, Hsiu-Chin; Chou, Fen-Pi

    2013-12-15

    Piper betel leaf (PBL) has the biological capabilities of detoxification and can work as an anti-inflammatory agent and an anti-oxidant. In this study, we evaluated the anti-oxidative activity of the extract of Piper betel leaves (PBLs) on the basis of Cu(2+)-mediated oxidation, and its ability to prevent foam cell formation in a model for oxidised low density lipoprotein (oxLDL)-induced lipid accumulation in macrophages. Our data demonstrated that PBLs were able to inhibit LDL oxidation in vitro and are able to reduce the lipid accumulation in macrophages. We showed the underlying mechanisms to be the following: PBLs up-regulated the protein levels of the class A and class B scavenger receptors, the membrane lipid transporter ABCA1, and its upstream regulator Liver X receptor (LXR) in the macrophages exposed to oxLDL. The results suggested that PBLs activated the reverse cholesterol transport mechanism to enhance the metabolism of the oxLDL that could prevent both lipid accumulation and foam cell formation and further minimise the possible damage of vessels caused by the oxLDL.

  17. Fabrication and densification enhancement of SiC-particulate-reinforced copper matrix composites prepared via the sinter-forging process

    Institute of Scientific and Technical Information of China (English)

    Mohammadmehdi Shabani; Mohammad Hossein Paydar; Mohammad Mohsen Moshksar

    2014-01-01

    The fabrication of copper (Cu) and copper matrix silicon carbide (Cu/SiCp) particulate composites via the sinter-forging process was investigated. Sintering and sinter-forging processes were performed under an inert Ar atmosphere. The influence of sinter-forging time, tempera-ture, and compressive stress on the relative density and hardness of the prepared samples was systematically investigated and subsequently com-pared with that of the samples prepared by the conventional sintering process. The relative density and hardness of the composites were enhanced when they were prepared by the sinter-forging process. The relative density values of all Cu/SiCp composite samples were observed to decrease with the increase in SiC content.

  18. Influence of arbuscular mycorrhizal fungi and copper on growth, accumulation of osmolyte, mineral nutrition and antioxidant enzyme activity of pepper (Capsicum annuum L.).

    Science.gov (United States)

    Abdel Latef, Arafat Abdel Hamed

    2011-08-01

    The effect of arbuscular mycorrhizal (AM) fungi inoculation on pepper (Capsicum annuum L. cv. Zhongjiao 105) plant growth and on some physiological parameters in response to increasing soil Cu concentrations was studied. Treatments consisted of inoculation or not with Glomus mosseae and the addition of Cu to soil at the concentrations of 0 (control), 2 (low), 4 (medium), and 8 (high) mM CuSO(4). AM fungal inoculation decreased Cu concentrations in plant organs and promoted biomass yields as well as the contents of chlorophyll, soluble sugar, total protein, and the concentrations of P, K, Ca, and Mg. Plants grown in high Cu concentration exhibited a Cu-induced proline accumulation and also an increase in total free amino acid contents; however, both were lower in mycorrhizal pepper. Cu-induced oxidative stress by increasing lipid peroxidation rates and the activity of superoxide dismutase, catalase, ascorbate peroxidase and glutathione reductase, and AM symbiosis enhanced these antioxidant enzyme activities and decreased oxidative damage to lipids. In conclusion G. mosseae was able to maintain an efficient symbiosis with pepper plants in contaminated Cu soils, improving plant growth under these conditions, which is likely to be due to reduced Cu accumulation in plant tissues, reduced oxidative stress and damage to lipids, or enhanced antioxidant capacity.

  19. Enhanced acetyl-CoA production is associated with increased triglyceride accumulation in the green alga Chlorella desiccata.

    Science.gov (United States)

    Avidan, Omri; Brandis, Alexander; Rogachev, Ilana; Pick, Uri

    2015-07-01

    Triglycerides (TAGs) from microalgae can be utilized as food supplements and for biodiesel production, but little is known about the regulation of their biosynthesis. This work aimed to test the relationship between acetyl-CoA (Ac-CoA) levels and TAG biosynthesis in green algae under nitrogen deprivation. A novel, highly sensitive liquid chromatography mass spectrometry (LC-MS/MS) technique enabled us to determine the levels of Ac-CoA, malonyl-CoA, and unacetylated (free) CoA in green microalgae. A comparative study of three algal species that differ in TAG accumulation levels shows that during N starvation, Ac-CoA levels rapidly rise, preceding TAG accumulation in all tested species. The levels of Ac-CoA in the high TAG accumulator Chlorella desiccata exceed the levels in the moderate TAG accumulators Dunaliella tertiolecta and Chlamydomonas reinhardtii. Similarly, malonyl-CoA and free CoA levels also increase, but to lower extents. Calculated cellular concentrations of Ac-CoA are far lower than reported K mAc-CoA values of plastidic Ac-CoA carboxylase (ptACCase) in plants. Transcript level analysis of plastidic pyruvate dehydrogenase (ptPDH), the major chloroplastic Ac-CoA producer, revealed rapid induction in parallel with Ac-CoA accumulation in C. desiccata, but not in D. tertiolecta or C. reinhardtii. It is proposed that the capacity to accumulate high TAG levels in green algae critically depends on their ability to divert carbon flow towards Ac-CoA. This requires elevation of the chloroplastic CoA pool level and enhancement of Ac-CoA biosynthesis. These conclusions may have important implications for future genetic manipulation to enhance TAG biosynthesis in green algae.

  20. As-grown graphene/copper nanoparticles hybrid nanostructures for enhanced intensity and stability of surface plasmon resonance

    Science.gov (United States)

    Li, Yun-Fei; Dong, Feng-Xi; Chen, Yang; Zhang, Xu-Lin; Wang, Lei; Bi, Yan-Gang; Tian, Zhen-Nan; Liu, Yue-Feng; Feng, Jing; Sun, Hong-Bo

    2016-11-01

    The transfer-free fabrication of the high quality graphene on the metallic nanostructures, which is highly desirable for device applications, remains a challenge. Here, we develop the transfer-free method by direct chemical vapor deposition of the graphene layers on copper (Cu) nanoparticles (NPs) to realize the hybrid nanostructures. The graphene as-grown on the Cu NPs permits full electric contact and strong interactions, which results in a strong localization of the field at the graphene/copper interface. An enhanced intensity of the localized surface plasmon resonances (LSPRs) supported by the hybrid nanostructures can be obtained, which induces a much enhanced fluorescent intensity from the dye coated hybrid nanostructures. Moreover, the graphene sheets covering completely and uniformly on the Cu NPs act as a passivation layer to protect the underlying metal surface from air oxidation. As a result, the stability of the LSPRs for the hybrid nanostructures is much enhanced compared to that of the bare Cu NPs. The transfer-free hybrid nanostructures with enhanced intensity and stability of the LSPRs will enable their much broader applications in photonics and optoelectronics.

  1. Heavy metal accumulation and signal transduction in herbaceous and woody plants: Paving the way for enhancing phytoremediation efficiency.

    Science.gov (United States)

    Luo, Zhi-Bin; He, Jiali; Polle, Andrea; Rennenberg, Heinz

    2016-11-01

    Heavy metal (HM)-accumulating herbaceous and woody plants are employed for phytoremediation. To develop improved strategies for enhancing phytoremediation efficiency, knowledge of the microstructural, physiological and molecular responses underlying HM-accumulation is required. Here we review the progress in understanding the structural, physiological and molecular mechanisms underlying HM uptake, transport, sequestration and detoxification, as well as the regulation of these processes by signal transduction in response to HM exposure. The significance of genetic engineering for enhancing phytoremediation efficiency is also discussed. In herbaceous plants, HMs are taken up by roots and transported into the root cells via transmembrane carriers for nutritional ions. The HMs absorbed by root cells can be further translocated to the xylem vessels and unloaded into the xylem sap, thereby reaching the aerial parts of plants. HMs can be sequestered in the cell walls, vacuoles and the Golgi apparatuses. Plant roots initially perceive HM stress and trigger the signal transduction, thereby mediating changes at the molecular, physiological, and microstructural level. Signaling molecules such as phytohormones, reactive oxygen species (ROS) and nitric oxide (NO), modulate plant responses to HMs via differentially expressed genes, activation of the antioxidative system and coordinated cross talk among different signaling molecules. A number of genes participated in HM uptake, transport, sequestration and detoxification have been functionally characterized and transformed to target plants for enhancing phytoremediation efficiency. Fast growing woody plants hold an advantage over herbaceous plants for phytoremediation in terms of accumulation of high HM-amounts in their large biomass. Presumably, woody plants accumulate HMs using similar mechanisms as herbaceous counterparts, but the processes of HM accumulation and signal transduction can be more complex in woody plants.

  2. Strategic Feeding of Ammonium and Metal Ions for Enhanced GLA-Rich Lipid Accumulation in Cunninghamella bainieri 2A1

    Directory of Open Access Journals (Sweden)

    Shuwahida Shuib

    2014-01-01

    Full Text Available Strategic feeding of ammonium and metal ions (Mg2+, Mn2+, Fe3+, Cu2+, Ca2+, Co2+, and Zn2+ for enhanced GLA-rich lipid accumulation in C. bainieri 2A1 was established. When cultivated in nitrogen-limited medium, the fungus produced up to 30% lipid (g/g biomass with 12.9% (g/g lipid GLA. However, the accumulation of lipid stopped at 48 hours of cultivation although glucose was abundant. This event occurred in parallel to the diminishing activity of malic enzyme (ME, fatty acid synthase (FAS, and ATP citrate lyase (ACL as well as the depletion of metal ions in the medium. Reinstatement of the enzymes activities was achieved by feeding of ammonium tartrate, but no increment in the lipid content was observed. However, increment in lipid content from 32% to 50% (g/g biomass with 13.2% GLA was achieved when simultaneous feeding of ammonium, glucose, and metal ions was carried out. This showed that the cessation of lipid accumulation was caused by diminishing activities of the enzymes as well as depletion of the metal ions in the medium. Therefore, strategic feeding of ammonium and metal ions successfully reinstated enzymes activities and enhanced GLA-rich lipid accumulation in C. bainieri 2A1.

  3. The Effect of Copper and Selenium Nanocarboxylates on Biomass Accumulation and Photosynthetic Energy Transduction Efficiency of the Green Algae Chlorella Vulgaris.

    Science.gov (United States)

    Mykhaylenko, Natalia F; Zolotareva, Elena K

    2017-12-01

    Nanoaquachelates, the nanoparticles with the molecules of water and/or carboxylic acids as ligands, are used in many fields of biotechnology. Ultra-pure nanocarboxylates of microelements are the materials of spatial perspective. In the present work, the effects of copper and selenium nanoaquachelates carboxylated with citric acid on biomass accumulation of the green algae Chlorella vulgaris were examined. Besides, the efficiency of the reactions of the light stage of photosynthesis was estimated by measuring chlorophyll a fluorescence. The addition of 0.67-4 mg L(-1) of Cu nanocarboxylates resulted in the increase in Chlorella biomass by ca. 20%; however, their concentrations ranging from 20 to 40 mg L(-1) strongly inhibited algal growth after the 12th day of cultivation. Se nanocarboxylates at 0.4-4 mg L(-1) concentrations also stimulated the growth of C. vulgaris, and the increase in biomass came up to 40-45%. The addition of Se nanocarboxylates at smaller concentrations (0.07 or 0.2 mg L(-1)) at first caused the retardation of culture growth, but that effect disappeared after 18-24 days of cultivation. The addition of 2-4 mg L(-1) of Cu nanocarboxylates or 0.4-4 mg L(-1) of Se nanocarboxylates caused the evident initial increase in such chlorophyll a fluorescence parameters as maximal quantum yield of photosystem II photochemistry (F v/F m) and the quantum yield of photosystem II photochemistry in the light-adapted state (F v'/F m'). Photochemical fluorescence quenching coefficients declined after 24 days of growth with Cu nanocarboxylates, but they increased after 6 days of the addition of 2 or 4 mg L(-1) Se nanocarboxylates. Those alterations affected the overall quantum yield of the photosynthetic electron transport in photosystem II.

  4. The Effect of Copper and Selenium Nanocarboxylates on Biomass Accumulation and Photosynthetic Energy Transduction Efficiency of the Green Algae Chlorella Vulgaris

    Science.gov (United States)

    Mykhaylenko, Natalia F.; Zolotareva, Elena K.

    2017-02-01

    Nanoaquachelates, the nanoparticles with the molecules of water and/or carboxylic acids as ligands, are used in many fields of biotechnology. Ultra-pure nanocarboxylates of microelements are the materials of spatial perspective. In the present work, the effects of copper and selenium nanoaquachelates carboxylated with citric acid on biomass accumulation of the green algae Chlorella vulgaris were examined. Besides, the efficiency of the reactions of the light stage of photosynthesis was estimated by measuring chlorophyll a fluorescence. The addition of 0.67-4 mg L-1 of Cu nanocarboxylates resulted in the increase in Chlorella biomass by ca. 20%; however, their concentrations ranging from 20 to 40 mg L-1 strongly inhibited algal growth after the 12th day of cultivation. Se nanocarboxylates at 0.4-4 mg L-1 concentrations also stimulated the growth of C. vulgaris, and the increase in biomass came up to 40-45%. The addition of Se nanocarboxylates at smaller concentrations (0.07 or 0.2 mg L-1) at first caused the retardation of culture growth, but that effect disappeared after 18-24 days of cultivation. The addition of 2-4 mg L-1 of Cu nanocarboxylates or 0.4-4 mg L-1 of Se nanocarboxylates caused the evident initial increase in such chlorophyll a fluorescence parameters as maximal quantum yield of photosystem II photochemistry ( F v/ F m) and the quantum yield of photosystem II photochemistry in the light-adapted state ( F v'/ F m'). Photochemical fluorescence quenching coefficients declined after 24 days of growth with Cu nanocarboxylates, but they increased after 6 days of the addition of 2 or 4 mg L-1 Se nanocarboxylates. Those alterations affected the overall quantum yield of the photosynthetic electron transport in photosystem II.

  5. Non-effect of water hardness on the accumulation and toxicity of copper in a freshwater macrophyte (Ceratophyllum demersum): how useful are hardness-modified copper guidelines for protecting freshwater biota?

    Science.gov (United States)

    Markich, Scott J; King, Angus R; Wilson, Scott P

    2006-12-01

    Several nations have adopted hardness-modified copper (Cu) guidelines for protecting freshwater biota. However, there is a lack of good quality data and mechanistic understanding on the effects of true water hardness (calcium (Ca) and magnesium (Mg)) on the bioavailability and toxicity of Cu to freshwater biota, particularly macrophytes. This study determined the effect of true water hardness (35, 90 and 335 mg CaCO(3)/l, added as Ca and Mg chloride in a 1:1 mole ratio) on the cell surface binding affinity (log K), accumulation and toxicity (96 h growth (biomass and stem length) and photosynthetic pigment inhibition) of Cu in the free-floating submerged macrophyte, Ceratophyllum demersum, in a synthetic freshwater with constant alkalinity (16 mg CaCO(3)/l) and pH (7.0). There were no significant (P>0.05) differences in the cell surface binding affinity, accumulation or toxicity of Cu in C. demersum with a 10-fold increase in water hardness from 35 to 335 mg CaCO(3)/l. The mean 96 h EC(50) values (and 95% confidence intervals) for biomass, the most sensitive endpoint, were 8.4 (7.6-9.2), 8.9 (8.0-9.8) and 9.9 (9.1-10.7) microg/l Cu for 35, 90 and 335 mg CaCO(3)/l, respectively. Speciation calculations indicated only very small (1-6%) differences in the percentage distribution (i.e. bioavailability) of Cu over the hardness range. These collective results indicate no apparent competition between Cu and Ca/Mg for binding sites on the cell surface. Given that the mechanism of Cu uptake (via Cu-specific and Na-linked transporters) is fundamentally different to that of Cd, Ni, Pb and Zn (via Ca transporters), for which other hardness-dependent algorithms have been developed, it is doubtful whether a hardness-modified Cu guideline value will be sufficiently protective of sensitive freshwater biota, such as C. demersum, particularly in medium-hard fresh surface waters with low levels of dissolved organic carbon. The biotic ligand model offers a more flexible and mechanistic

  6. Systematic engineering of phytochelatin synthesis and arsenic transport for enhanced arsenic accumulation in E. coli.

    Science.gov (United States)

    Singh, Shailendra; Kang, Seung Hyun; Lee, Wonkyu; Mulchandani, Ashok; Chen, Wilfred

    2010-03-01

    Phytochelatin (PC) is a naturally occurring peptide with high affinity towards arsenic (As). In this article, we demonstrated the systematic engineering of PC-producing E. coli for As accumulation by addressing different bottlenecks in PC synthesis as well as As transport. Phytochelatin synthase from Schizosaccharomyces pombe (SpPCS) was expressed in E. coli resulting in 18 times higher As accumulation. PC production was further increased by co-expressing a feedback desensitized gamma-glutamylcysteine synthetase (GshI*), resulting in 30-fold higher PC levels and additional 2-fold higher As accumulation. The significantly increased PC levels were exploited further by co-expressing an arsenic transporter GlpF, leading to an additional 1.5-fold higher As accumulation. These engineering steps were finally combined in an arsenic efflux deletion E. coli strain to achieve an arsenic accumulation level of 16.8 micromol/g DCW, a 80-fold improvement when compared to a control strain not producing phytochelatins.

  7. Heavy Metals Accumulation in Topsoils from the Wine-growing Regions Part 2. Relationships between soil properties and extractable copper contents

    Directory of Open Access Journals (Sweden)

    Marija Romić

    2004-09-01

    Full Text Available The present study analyses the effects of high copper concentrations on its mobility in the soils from the wine-growing regions of the Northwestern Croatia. The aims of this study were to determine the copper distribution in vineyard soils by single extraction procedures, and to relate the total, mobile and mobilisable copper content to several chemical soil characteristics using multiple regression analysis. The total Cu concentrations were determined by an aqua regia procedure. Two other methods were used for evaluating soil available copper: DTPA extraction and calcium chloride extraction. The physical and chemical characteristics (texture, organic C, pH, CaCO3, total P, CEC were determined as well. Both DTPA- and CaCl2-extractable copper were largely explained by the total copper contents, and they were also highly correlated to each other. It was found that the DTPA-extractable copper decreased with increasing cation exchange capacity, but concentrations of CaCl2-extractable copper mainly depend on pH.

  8. Photo-Oxidative Stress-Driven Mutagenesis and Adaptive Evolution on the Marine Diatom Phaeodactylum tricornutum for Enhanced Carotenoid Accumulation

    Directory of Open Access Journals (Sweden)

    Zhiqian Yi

    2015-09-01

    Full Text Available Marine diatoms have recently gained much attention as they are expected to be a promising resource for sustainable production of bioactive compounds such as carotenoids and biofuels as a future clean energy solution. To develop photosynthetic cell factories, it is important to improve diatoms for value-added products. In this study, we utilized UVC radiation to induce mutations in the marine diatom Phaeodactylum tricornutum and screened strains with enhanced accumulation of neutral lipids and carotenoids. Adaptive laboratory evolution (ALE was also used in parallel to develop altered phenotypic and biological functions in P. tricornutum and it was reported for the first time that ALE was successfully applied on diatoms for the enhancement of growth performance and productivity of value-added carotenoids to date. Liquid chromatography-mass spectrometry (LC-MS was utilized to study the composition of major pigments in the wild type P. tricornutum, UV mutants and ALE strains. UVC radiated strains exhibited higher accumulation of fucoxanthin as well as neutral lipids compared to their wild type counterpart. In addition to UV mutagenesis, P. tricornutum strains developed by ALE also yielded enhanced biomass production and fucoxanthin accumulation under combined red and blue light. In short, both UV mutagenesis and ALE appeared as an effective approach to developing desired phenotypes in the marine diatoms via electromagnetic radiation-induced oxidative stress.

  9. Synthetic phytochelatins complement a phytochelatin-deficient Arabidopsis mutant and enhance the accumulation of heavy metal(loid)s.

    Science.gov (United States)

    Shukla, Devesh; Tiwari, Manish; Tripathi, Rudra D; Nath, Pravendra; Trivedi, Prabodh Kumar

    2013-05-10

    Phytochelatins (PCs) are naturally occurring thiol-rich peptides containing gamma (γ) peptide bonds and are well known for their metal-binding and detoxification capabilities. Whether synthetic phytochelatins (ECs) can be used as an alternative approach for enhancing the metal-binding capacity of plants has been investigated in this study. The metal-binding potential of ECs has been demonstrated in bacteria; however, no report has investigated the expression of ECs in plants. We have expressed three synthetic genes encoding ECs of different lengths in wild type (WT) Arabidopsis (Col-0 background) and a phytochelatin-deficient Arabidopsis mutant (cad1-3). After exposure to different heavy metals, the transgenic plants were examined for phenotypic changes, and metal accumulation was evaluated. The expression of EC genes rescued the sensitive phenotype of the cad1-3 mutant under heavy metal(loid) stress. Transgenic Arabidopsis plants expressing EC genes accumulated a significantly enhanced level of heavy metal(loid)s in comparison with the WT plant. The mutant complementation and enhanced heavy metal(loid) accumulation in the transgenic Arabidopsis plants suggest that ECs work in a manner similar to that of PCs in plants and that ECs could be used as an alternative for phytoremediation of heavy metal(loid) exposure.

  10. Enhanced electrochemical methanation of carbon dioxide with a dispersible nanoscale copper catalyst.

    Science.gov (United States)

    Manthiram, Karthish; Beberwyck, Brandon J; Alivisatos, A Paul

    2014-09-24

    Although the vast majority of hydrocarbon fuels and products are presently derived from petroleum, there is much interest in the development of routes for synthesizing these same products by hydrogenating CO2. The simplest hydrocarbon target is methane, which can utilize existing infrastructure for natural gas storage, distribution, and consumption. Electrochemical methods for methanizing CO2 currently suffer from a combination of low activities and poor selectivities. We demonstrate that copper nanoparticles supported on glassy carbon (n-Cu/C) achieve up to 4 times greater methanation current densities compared to high-purity copper foil electrodes. The n-Cu/C electrocatalyst also exhibits an average Faradaic efficiency for methanation of 80% during extended electrolysis, the highest Faradaic efficiency for room-temperature methanation reported to date. We find that the level of copper catalyst loading on the glassy carbon support has an enormous impact on the morphology of the copper under catalytic conditions and the resulting Faradaic efficiency for methane. The improved activity and Faradaic efficiency for methanation involves a mechanism that is distinct from what is generally thought to occur on copper foils. Electrochemical data indicate that the early steps of methanation on n-Cu/C involve a pre-equilibrium one-electron transfer to CO2 to form an adsorbed radical, followed by a rate-limiting non-electrochemical step in which the adsorbed CO2 radical reacts with a second CO2 molecule from solution. These nanoscale copper electrocatalysts represent a first step toward the preparation of practical methanation catalysts that can be incorporated into membrane-electrode assemblies in electrolyzers.

  11. Eu3 + amidst ionic copper in glass: Enhancement through energy transfer from Cu+, or quenching by Cu2 +?

    Science.gov (United States)

    Jiménez, José A.

    2017-02-01

    A barium-phosphate glass system doped with europium(III) and containing a high concentration of copper(I) together with a copper(II) remnant has been studied spectroscopically. The main object is to elucidate whether the orange-red emission of Eu3 + ions succeeds through sensitization via luminescent Cu+ ions or else is preferentially quenched by non-radiative transfer to Cu2 +. A characterization of the melt-quenched glass was first performed by UV/Vis optical absorption, 31P nuclear magnetic resonance and infrared absorption spectroscopy. A photoluminescence (PL) spectroscopy and emission decay dynamics assessment was subsequently performed. Despite the concentration of Cu+ being estimated to be much higher than that of Cu2 +, the data shows that quenching of Eu3 + PL by Cu2 + dominates. The lifetime analysis of emitting centers Cu+ and Eu3 + points to the origin of the manifestation being that the Eu3 + → Cu2 + non-radiative transfer rate responsible for the quenching is almost two times higher than that for the Cu+ → Eu3 + transfer accountable for the enhancement. Finally, an effort was made for the determination of Cu2 + in the glass containing Cu+, Cu2 + and Eu3 + ions based on the Eu3 + (5D0) emission decay rates. It was found to be in excellent agreement with the UV/Vis spectrophotometric approach, thus supporting the utility of Eu3 + ions for optical sensing of copper(II) in the solid state.

  12. Highly sensitive visual detection of copper (II) using water-soluble azide-functionalized gold nanoparticles and silver enhancement.

    Science.gov (United States)

    Zhang, Zhen; Li, Wenqing; Zhao, Qiuling; Cheng, Ming; Xu, Li; Fang, Xiaohong

    2014-09-15

    A high-sensitive method for the visual detection of copper ions in aqueous solution is developed. The method is based on copper ion-catalyzed 'click' reaction between the water-soluble azide-functionalized gold nanoparticles (AuNPs) and alkyne-modified glass slide. The PEG linker was employed as a stabilizing component along with the terminal azide group to keep the AuNPs stably dispersed in water without the assistance of any organic solvent. In the presence of copper ions, the AuNPs are 'clicked' on the slide, and the darkness of the AuNPs in the sample spot is promoted by silver enhancement process. Only a tiny amount of sample (10 μl) is needed with the detectable concentration down to 62 pM by the commonly used flatbed scanner, which is 2-3 orders of magnitude lower than those in previous reports. The selectivity relative to other potentially interfering ions and the applicability in real samples, human serum and tap water, have also been evaluated. Our method has a good potential in point-of-use applications and environment surveys. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Photocurrent enhancement of d.c. sputtered copper oxide thin films

    Indian Academy of Sciences (India)

    P Samarasekara; M A K Mallika Arachchi; A S Abeydeera; C A N Fernando; A S Disanayake; R M G Rajapakse

    2005-08-01

    Copper oxide (CuO) thin films with photocurrent as high as 25 Α/cm2 were deposited on conductive glass substrates using d.c. reactive sputtering. This was the highest reported photocurrent for sputtered -type copper oxide measured in the electrolyte KI. The photocurrent drastically increased up to 25 Α/cm2 as the sputtering pressure and the substrate temperature were increased up to 8.5 mbar and 192°C, respectively. All the synthesized films contained single phase of CuO in this range of pressure and substrate temperature. Variation of the photocurrent, photovoltage, structure and absorbance with deposition conditions were studied in detail.

  14. Cost effective nanostructured copper substrates prepared with ultrafast laser pulses for explosives detection using surface enhanced Raman scattering

    Energy Technology Data Exchange (ETDEWEB)

    Hamad, Syed [School of Physics, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Podagatlapalli, G. Krishna; Soma, Venugopal Rao, E-mail: svrsp@uohyd.ernet.in, E-mail: soma-venu@yahoo.com [Advanced Center of Research in High Energy Materials (ACRHEM), University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India); Mohiddon, Md. Ahamad [Center for Nanotechnology, University of Hyderabad, Prof. C. R. Rao Road, Hyderabad 500046 (India)

    2014-06-30

    Ultrafast laser pulses induced surface nanostructures were fabricated on a copper (Cu) target through ablation in acetone, dichloromethane, acetonitrile, and chloroform. Surface morphological information accomplished from the field emission scanning electron microscopic data demonstrated the diversities of ablation mechanism in each case. Fabricated Cu substrates were utilized exultantly to investigate the surface plasmon (localized and propagating) mediated enhancements of different analytes using surface enhance Raman scattering (SERS) studies. Multiple utility of these substrates were efficiently demonstrated by collecting the SERS data of Rhodamine 6G molecule and two different secondary explosive molecules such as 5-amino-3-nitro-l,2,4-triazole and trinitrotoluene on different days which were weeks apart. We achieved significant enhancement factors of >10{sup 5} through an easily adoptable cleaning procedure.

  15. Enhanced interfacial strength of carbon nanotube/copper nanocomposites via Ni-coating: Molecular-dynamics insights

    Science.gov (United States)

    Duan, Ke; Li, Li; Hu, Yujin; Wang, Xuelin

    2017-04-01

    The molecular bridging between carbon nanotube (CNT) within the meta matrix is hopeful for enhancing nanocomposite's mechanical performance. One of the main problems for nanocomposites is the inadequate bonding between nonstructural reinforcement and meta matrix. Ni-coating on CNT is an effective method to overcome the drawback of the inadequate strength, but the enhancing mechanism has not well interpreted yet. In this paper, the enhancing mechanism will be interpreted from the molecular-dynamics insights. The pullout process of CNT and Ni-coated CNT against copper matrix is investigated. The effects of geometric parameters, including CNT length and diameter, are taken into considerations and discussed. Results show that the interfacial strength is significantly improved after the Ni-coated CNT, which shows a good agreement with the experimental results available in the open literature. Besides, the sliding mechanism of Ni-coated CNTs against copper matrix is much more like a kind of friction sliding and directly related to the embedded zone. However, the pullout force of the CNT without Ni-coating is nearly proportional to its diameter, but independent of embedded length.

  16. Cadmium accumulation is enhanced by ammonium compared to nitrate in two hyperaccumulators, without affecting speciation.

    Science.gov (United States)

    Cheng, Miaomiao; Wang, Peng; Kopittke, Peter M; Wang, Anan; Sale, Peter W G; Tang, Caixian

    2016-09-01

    Nitrogen fertilization could improve the efficiency of Cd phytoextraction in contaminated soil and thus shorten the remediation time. However, limited information is available on the effect of N form on Cd phytoextraction and associated mechanisms in plants. This study examined the effect of N form on Cd accumulation, translocation, and speciation in Carpobrotus rossii and Solanum nigrum Plants were grown in nutrient solution with 5-15 μM Cd in the presence of 1000 µM NH4 (+) or NO3 (-) Plant growth and Cd uptake were measured, and Cd speciation was analyzed using synchrotron-based X-ray absorption spectroscopy. Shoot Cd accumulation was 30% greater with NH4 (+) than NO3 (-) supply. Carpobrotus rossii accumulated three times more Cd than S. nigrum. However, Cd speciation in the plants was not influenced by N form, but it did vary with species and tissues. In C. rossii, up to 91% of Cd was bound to S-containing ligands in all tissues except the xylem sap where 87-95% were Cd-OH complexes. Furthermore, the proportion of Cd-S in shoots was substantially lower in S. nigrum (44-69%) than in C. rossii (60-91%). It is concluded that the application of NH4 (+) (instead of NO3 (-)) increased shoot Cd accumulation by increasing uptake and translocation, rather than changing Cd speciation, and is potentially an effective approach for increasing Cd phytoextraction.

  17. BIOLOGY OF POLYPHOSPHATE-ACCUMULATING BACTERIA INVOLVED IN ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL

    NARCIS (Netherlands)

    KORTSTEE, GJJ; APPELDOORN, KJ; BONTING, CFC; VANNIEL, EWJ; VANVEEN, HW

    1994-01-01

    Recent research on the process of biological phosphorus removal in lab-scale treatment systems has indicated that: (i) the development of an actively polyP-accumulating bacterial community after the introduction of an anaerobic period may take at least 4 months; (ii) up to 80% of all aerobic

  18. BIOLOGY OF POLYPHOSPHATE-ACCUMULATING BACTERIA INVOLVED IN ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL

    NARCIS (Netherlands)

    KORTSTEE, GJJ; APPELDOORN, KJ; BONTING, CFC; VANNIEL, EWJ; VANVEEN, HW

    1994-01-01

    Recent research on the process of biological phosphorus removal in lab-scale treatment systems has indicated that: (i) the development of an actively polyP-accumulating bacterial community after the introduction of an anaerobic period may take at least 4 months; (ii) up to 80% of all aerobic bacteri

  19. BIOLOGY OF POLYPHOSPHATE-ACCUMULATING BACTERIA INVOLVED IN ENHANCED BIOLOGICAL PHOSPHORUS REMOVAL

    NARCIS (Netherlands)

    KORTSTEE, GJJ; APPELDOORN, KJ; BONTING, CFC; VANNIEL, EWJ; VANVEEN, HW

    1994-01-01

    Recent research on the process of biological phosphorus removal in lab-scale treatment systems has indicated that: (i) the development of an actively polyP-accumulating bacterial community after the introduction of an anaerobic period may take at least 4 months; (ii) up to 80% of all aerobic bacteri

  20. Expression of cadR Enhances its Specific Activity for Cd Detoxification and Accumulation in Arabidopsis.

    Science.gov (United States)

    Li, Jingrui; Wei, Xuezhi; Yu, Pengli; Deng, Xin; Xu, Wenxiu; Ma, Mi; Zhang, Haiyan

    2016-08-01

    Cadmium (Cd) is a transition metal that is highly toxic in biological systems. Anthropogenic emissions of Cd have increased biogeochemical cycling and the amount of Cd in the biosphere. Here we studied the utility of a bacterial Cd-binding protein, CadR, for the remediation of Cd contamination. CadR was successfully targeted to chloroplasts using a constitutive Cauliflower mosaic virus (CaMV) 35S promoter or a shoot-specific Chl a/b-binding protein 2 gene (CAB2) promoter and an RbcS (small subunit of the Rubisco complex) transit peptide. Under short-term (2 d) exposure to Cd, the cadR transgenic plants showed up to a 2.9-fold Cd accumulation in roots compared with untransformed plants. Under medium term (7 d) exposure to Cd, the concentrations of Cd in leaves began to increase but there were no differences between the wild type and the cadR transgenic plants. Under long-term (16 d) exposure to Cd, the cadR transgenic plants accumulated greater amounts of Cd in leaves than the untransformed plants. Total Cd accumulation (µg per plant) in shoots and roots of the plants expressing cadR were significantly higher (up to 3.5-fold in shoots and 5.2-fold in roots) than those of the untransformed plants. We also found that targeting CadR to chloroplasts facilitated chloroplastic metal homeostasis and Chl b accumulation. Our results demonstrate that manipulating chelating capacity in chloroplasts or in the cytoplasm may be effective in modifying both the accumulation of and resistance to Cd.

  1. Enhancement of leaching copper by electro-oxidation from metal powders of waste printed circuit board.

    Science.gov (United States)

    Ping, Zhu; ZeYun, Fan; Jie, Lin; Qiang, Liu; Guangren, Qian; Ming, Zhou

    2009-07-30

    Oxidation leaching copper from metal powders of waste printed circuit boards (PCBs) was conducted at room temperature in sulfuric acid solution. The result showed that the copper in metal powders was oxidized by Cu(2+) to form CuCl(2)(-) in the presence of chloride ion without electrochemical oxidation. Then, CuCl(2)(-) was oxidized into CuSO(4) by oxygen derived from the air insufflated into leaching solution. The leaching rate of copper reached 100%. The whole reaction took 5.5h because it was limited by the low solubility of the air in water. In the electro-oxidation conditions, the chloride ion was electro-oxidized into ClO(-), which oxidized CuCl(2)(-) into CuSO(4) and ClO(-) was reduced into Cl(-) itself again at the same time. Since Cl(-) was recycled in the solution not only as a complexing agent but also as an oxidant, which made the reaction speed up to 3.5h to reach 100% leaching rate. Leaching solution was concentrated to crystallize CuSO(4).5H(2)O, and crystal liquor was reused to leach copper from metal powders.

  2. Ascorbic acid enhances the accumulation of polycyclic aromatic hydrocarbons (PAHs in roots of tall fescue (Festuca arundinacea Schreb..

    Directory of Open Access Journals (Sweden)

    Yanzheng Gao

    Full Text Available Plant contamination by polycyclic aromatic hydrocarbons (PAHs is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA significantly reduced the activities of peroxidase (POD and polyphenol oxidase (PPO, thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.. POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP, phenanthrene (PHE and anthracene (ANT. The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality.

  3. Ascorbic acid enhances the accumulation of polycyclic aromatic hydrocarbons (PAHs) in roots of tall fescue (Festuca arundinacea Schreb.).

    Science.gov (United States)

    Gao, Yanzheng; Li, Hui; Gong, Shuaishuai

    2012-01-01

    Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality.

  4. Sulfur Dioxide Enhances Endogenous Hydrogen Sulfide Accumulation and Alleviates Oxidative Stress Induced by Aluminum Stress in Germinating Wheat Seeds

    Directory of Open Access Journals (Sweden)

    Dong-Bo Zhu

    2015-01-01

    Full Text Available Aluminum ions are especially toxic to plants in acidic soils. Here we present evidences that SO2 protects germinating wheat grains against aluminum stress. SO2 donor (NaHSO3/Na2SO3 pretreatment at 1.2 mM reduced the accumulation of superoxide anion, hydrogen peroxide, and malondialdehyde, enhanced the activities of guaiacol peroxidase, catalase, and ascorbate peroxidase, and decreased the activity of lipoxygenase in germinating wheat grains exposed to Al stress. We also observed higher accumulation of hydrogen sulfide (H2S in SO2-pretreated grain, suggesting the tight relation between sulfite and sulfide. Wheat grains geminated in water for 36 h were pretreated with or without 1 mM SO2 donor for 12 h prior to exposure to Al stress for 48 h and the ameliorating effects of SO2 on wheat radicles were studied. SO2 donor pretreatment reduced the content of reactive oxygen species, protected membrane integrity, and reduced Al accumulation in wheat radicles. Gene expression analysis showed that SO2 donor pretreatment decreased the expression of Al-responsive genes TaWali1, TaWali2, TaWali3, TaWali5, TaWali6, and TaALMT1 in radicles exposed to Al stress. These results suggested that SO2 could increase endogenous H2S accumulation and the antioxidant capability and decrease endogenous Al content in wheat grains to alleviate Al stress.

  5. Naturally evolved enhanced Cd tolerance of Dianthus carthusianorum L. is not related to accumulation of thiol peptides and organic acids.

    Science.gov (United States)

    Wójcik, Małgorzata; Dresler, Sławomir; Plak, Andrzej; Tukiendorf, Anna

    2015-05-01

    Two contrasting ecotypes of Dianthus carthusianorum L., metallicolous (M) and nonmetallicolous (NM), were cultivated in hydroponics at 0-50 μM Cd for 14 days to compare their Cd accumulation, sensitivity and tolerance mechanisms. While both ecotypes contained similar concentrations of Cd in the shoots and roots, the M ecotype was more Cd-tolerant (as measured by fresh weight production and root and leaf viability). Both ecotypes accumulated phytochelatins (PCs) in response to Cd with a higher amount thereof found in the NM ecotype. Concentrations of PCs remained unchanged with increasing Cd concentrations in the root tissues, but their content in the shoots increased. The addition of L-buthionine-sulfoximine (BSO) diminished glutathione (GSH) accumulation and arrested PC production, which increased the sensitivity to Cd of the NM, but not M ecotype. Organic acids (malate and citrate) as well as proline accumulation did not change significantly after Cd exposition and was at the same level in both ecotypes. The enhanced Cd tolerance of the M ecotype of D. carthusianorum cannot be explained in terms of restricted Cd uptake and differential production of PCs, organic acids or proline; some other mechanisms must be involved in its adaptation to the high Cd content in the environment.

  6. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: I. Autotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the microalgae-growth promoting bacterium Azospirillum brasilense on accumulation of total carbohydrates and starch in two species of Chlorella (Chlorella vulgaris and Chlorella sorokiniana), when the bacterium and each microalga were jointly immobilized in alginate beads was studied under autotrophic conditions for 144 h in synthetic medium. The interaction of the bacterium with the microalgae enhanced accumulation of total carbohydrate and starch. Cells of Chlorella accumulated the highest amounts of carbohydrate after incubation for 24h. Yet, this did not coincide with the highest affinity and volumetric productivity measured in these cultures. However, after incubation for 72 h, mainly in jointly immobilized treatments of both microalgae species, the cultures reached their highest total carbohydrate content (mainly as starch) and also the highest affinity and volumetric productivity. These results demonstrate the potential of A. brasilense to affect carbohydrates and starch accumulation in Chlorella spp. when both microorganisms are co-cultured, which can be an important tool for applications of microalgae.

  7. Red mud (RM)-Induced enhancement of iron plaque formation reduces arsenic and metal accumulation in two wetland plant species.

    Science.gov (United States)

    Yang, J X; Guo, Q J; Yang, J; Zhou, X Y; Ren, H Y; Zhang, H Z; Xu, R X; Wang, X D; Peters, M; Zhu, G X; Wei, R F; Tian, L Y; Han, X K

    2016-01-01

    Human activities have resulted in arsenic (As) and heavy metals accumulation in paddy soils in China. Phytoremediation has been suggested as an effective and low-cost method to clean up contaminated soils. A combined soil-sand pot experiment was conducted to investigate the influence of red mud (RM) supply on iron plaque formation and As and heavy metal accumulation in two wetland plant species (Cyperus alternifolius Rottb., Echinodorus amazonicus Rataj), using As and heavy metals polluted paddy soil combined with three rates of RM application (0, 2%, 5%). The results showed that RM supply significantly decreased As and heavy metals accumulation in shoots of the two plants due to the decrease of As and heavy metal availability and the enhancement of the formation of iron plaque on the root surface and in the rhizosphere. Both wetland plants supplied with RM tended to have more Fe plaque, higher As and heavy metals on roots and in their rhizospheres, and were more tolerant of As and heavy metal toxicity. The results suggest that RM-induced enhancement of the formation of iron plaque on the root surface and in the rhizosphere of wetland plants may be significant for remediation of soils contaminated with As and heavy metals.

  8. Enhanced accumulation of starch and total carbohydrates in alginate-immobilized Chlorella spp. induced by Azospirillum brasilense: II. Heterotrophic conditions.

    Science.gov (United States)

    Choix, Francisco J; de-Bashan, Luz E; Bashan, Yoav

    2012-10-10

    The effect of the bacterium Azospirillum brasilense jointly immobilized with Chlorella vulgaris or C. sorokiniana in alginate beads on total carbohydrates and starch was studied under dark and heterotrophic conditions for 144 h in synthetic growth medium supplemented with either d-glucose or Na-acetate as carbon sources. In all treatments, enhanced total carbohydrates and starch content per culture and per cell was obtained after 24h; only jointly immobilized C. vulgaris growing on d-glucose significantly increased total carbohydrates and starch content after 96 h. Enhanced accumulation of carbohydrate and starch under jointly immobilized conditions was variable with time of sampling and substrate used. Similar results occurred when the microalgae was immobilized alone. In both microalgae growing on either carbon sources, the bacterium promoted accumulation of carbohydrates and starch; when the microalgae were immobilized alone, they used the carbon sources for cell multiplication. In jointly immobilized conditions with Chlorella spp., affinity to carbon source and volumetric productivity and yield were higher than when Chlorella spp. were immobilized alone; however, the growth rate was higher in microalgae immobilized alone. This study demonstrates that under heterotrophic conditions, A. brasilense promotes the accumulation of carbohydrates in two strains Chlorella spp. under certain time-substrate combinations, producing mainly starch. As such, this bacterium is a biological factor that can change the composition of compounds in microalgae in dark, heterotrophic conditions.

  9. Proteomic analysis of Chlorella vulgaris: Potential targets for enhanced lipid accumulation

    Energy Technology Data Exchange (ETDEWEB)

    Guarnieri, Michael T.; Nag, Ambarish; Yang, Shihui; Pienkos, Philip T.

    2013-11-01

    Oleaginous microalgae are capable of producing large quantities of fatty acids and triacylglycerides. As such, they are promising feedstocks for the production of biofuels and bioproducts. Genetic strain-engineering strategies offer a means to accelerate the commercialization of algal biofuels by improving the rate and total accumulation of microalgal lipids. However, the industrial potential of these organisms remains to be met, largely due to the incomplete knowledgebase surrounding the mechanisms governing the induction of algal lipid biosynthesis. Such strategies require further elucidation of genes and gene products controlling algal lipid accumulation. In this study, we have set out to examine these mechanisms and identify novel strain-engineering targets in the oleaginous microalga, Chlorella vulgaris. Comparative shotgun proteomic analyses have identified a number of novel targets, including previously unidentified transcription factors and proteins involved in cell signaling and cell cycle regulation. These results lay the foundation for strain-improvement strategies and demonstrate the power of translational proteomic analysis.

  10. Dissolved inorganic carbon enhanced growth, nutrient uptake, and lipid accumulation in wastewater grown microalgal biofilms.

    Science.gov (United States)

    Kesaano, Maureen; Gardner, Robert D; Moll, Karen; Lauchnor, Ellen; Gerlach, Robin; Peyton, Brent M; Sims, Ronald C

    2015-03-01

    Microalgal biofilms grown to evaluate potential nutrient removal options for wastewaters and feedstock for biofuels production were studied to determine the influence of bicarbonate amendment on their growth, nutrient uptake capacity, and lipid accumulation after nitrogen starvation. No significant differences in growth rates, nutrient removal, or lipid accumulation were observed in the algal biofilms with or without bicarbonate amendment. The biofilms possibly did not experience carbon-limited conditions because of the large reservoir of dissolved inorganic carbon in the medium. However, an increase in photosynthetic rates was observed in algal biofilms amended with bicarbonate. The influence of bicarbonate on photosynthetic and respiration rates was especially noticeable in biofilms that experienced nitrogen stress. Medium nitrogen depletion was not a suitable stimulant for lipid production in the algal biofilms and as such, focus should be directed toward optimizing growth and biomass productivities to compensate for the low lipid yields and increase nutrient uptake.

  11. Strategies for enhancing monoclonal antibody accumulation in plant cell and organ cultures.

    Science.gov (United States)

    Sharp, J M; Doran, P M

    2001-01-01

    Various strategies aimed at improving IgG(1) antibody accumulation in transgenic tobacco cell and organ cultures were tested. The form of tissue had a significant effect on antibody levels; shooty teratomas were less productive than hairy roots or suspended cells. Although there were several disadvantages associated with hairy roots compared with suspensions, such as slower growth, slower antibody production, and formation of a greater number of antibody fragments, the roots exhibited superior long-term culture stability. Antibody accumulation in hairy root cultures was improved by increasing the dissolved oxygen tension to 150% air saturation, indicating the need for effective oxygen transfer in root reactors used for antibody production. Preventing N-linked glycosylation using tunicamycin or inhibition of subsequent glycan processing by castanospermine reduced antibody accumulation in the biomass and/or medium in cell suspensions. Loss of antibody from the cultures after its secretion and release into the medium was identified as a major problem. This effect was minimized by inhibiting protein transport in the secretory pathway using Brefeldin A, resulting in antibody accumulation levels up to 2.7 times those in untreated cells. Strategies for protecting secreted antibody, such as addition of poly(vinylpyrrolidone) and periodic harvesting from the medium using hydroxyapatite resin, also increased antibody titers. The mechanisms responsible for the disappearance of antibody from plant culture media were not clearly identified; degradation by proteases and conformational modification of the antibody, such as formation of aggregates, provided an explanation for some but not all the phenomena observed. This work demonstrates that the manipulation and control of culture conditions and metabolic processes in plant tissue cultures can be used to improve the production of foreign proteins. However, loss of secreted antibody from plant culture medium is a significant

  12. Jasmonic acid enhancement of anthocyanin accumulation is dependent on phytochrome A signaling pathway under far-red light in Arabidopsis.

    Science.gov (United States)

    Li, Ting; Jia, Kun-Peng; Lian, Hong-Li; Yang, Xu; Li, Ling; Yang, Hong-Quan

    2014-11-07

    Anthocyanins are critical for plants. It is shown that the expression of genes encoding the key enzymes such as dihydroflavonol 4-reductase (DFR), UDP-Glc: flavonoid 3-O-glucosyltransferase (UF3GT), and leucoanthocyanidin dioxygenase (LDOX) in anthocyanin biosynthesis pathway is regulated by MYB75, a R2R3 MYB transcription factor. The production of anthocyanin is known to be promoted by jasmonic acid (JA) in light but not in darkness. The photoreceptors cryptochrome 1 (CRY1), phytochrome B (phyB), and phytochrome A (phyA) are also shown to mediate light promotion of anthocyanin accumulation, respectively, whereas their downstream factor COP1, a master negative regulator of photomorphogensis, represses anthocyanin accumulation. However, whether JA coordinates with photoreceptors in the regulation of anthocyanin accumulation is unknown. Here, we show that under far-red light, JA promotes anthocyanin accumulation in a phyA signaling pathway-dependent manner. The phyA mutant is hyposensitive to jasmonic acid analog methyl jasmonic acid (MeJA) under far-red light. The dominant mutant of MYB75, pap1-D, accumulates significantly higher levels of anthocyanin than wild type under far-red light, whereas knockdown of MYBs (MYB75, MYB90, MYB113, and MYB114) through RNAi significantly reduces MeJA promotion of anthocyanin accumulation. The phyA pap1-D double mutant shows reduced responsiveness to MeJA, similar to phyA mutant under far-red light. In darkness, a mutant allele of cop1, cop1-4, shows enhanced responsiveness to MeJA, but pap1-D mutant is barely responsive to MeJA. Upon MeJA application, the cop1-4 pap1-D double mutant accumulates considerably higher levels of anthocyanin than cop1-4 in darkness. Protein studies indicate that MYB75 protein is stabilized by white light and far-red light. Further gene expression studies suggest that MeJA promotes the expression of DFR, UF3GT, and LDOX genes in a phyA- and MYB75-dependent manner under far-red light. Our findings suggest

  13. Low medium pH value enhances anthocyanin accumulation in Malus crabapple leaves.

    Directory of Open Access Journals (Sweden)

    Yanchen Zhang

    Full Text Available Anthocyanin is a critical factor involved in coloration of plant tissues, but the mechanism how medium pH values affect anthocyanin accumulation in woody plants is unknown. We analyzed anthocyanin composition and the expression of elements encoding anthocyanin and flavonols biosynthesis underlying different medium pH values by using three different leave color type cultivars. HPLC analysis demonstrated that high medium pH values treatment induced a dramatic decrease in the concentration of cyaniding in crabapple leaves. Conversely, the high medium pH values induced up-regulation of the content of flavones and flavonols, suggesting that low pH treatment-induced anthocyanin accumulation. Quantitative real time PCR experiment showed the expression level of anthocyanidin synthase (McANS and uridine diphosphate glucose flavonoid 3-O-glucosyltransferase (McUFGT was up-regulated by low pH values treatment, and high medium pH value treatment up-regulate the transcription level of flavonol synthase (McFLS. Meanwhile, several MYB TFs have been suggested in the regulation of pH responses. These results strongly indicate that the low pH treatment-induced anthocyanin accumulation is mediated by the variation of mRNA transcription of the anthocyanin biosynthetic genes.

  14. Effects of calcium, magnesium and sodium chloride in enhancing lipid accumulation in two green microalgae.

    Science.gov (United States)

    Gorain, Prakash Chandra; Bagchi, Sourav Kumar; Mallick, Nirupama

    2013-01-01

    Biodiesel from microalgae has the potential as a sustainable fuel, since some species show exceptionally high lipid accumulation potential under various stresses. Effects of different concentrations of Ca, Mg and NaCl in the growth medium on biomass yield and lipid accumulation of Chlorella vulgaris and Scenedesmus obliquus grown under batch culture mode were investigated. Starvation of Mg showed a marginal rise in lipid content for a short period of time. Ca-starved cultures, however, demonstrated a profound rise in lipid content, i.e. 40% of dry cell wt. (dcw) was recorded against 11.9% control for C. vulgaris and 37% (dcw) against 11.3% for S. obliquus. Under increased concentration of Mg, significant rise in biomass and lipid yield was recorded. Effect of NaCl-induced osmotic stress showed lipid accumulation of approximately 40% (dcw) in both the test algae, whereas the biomass yield was severely affected. The fatty acid profiles under the above stresses were analysed and discussed.

  15. Bio-accumulation of copper, zinc, iron and manganese in oyster Saccostrea cucullata, Snail Cerithium rubus and Clam Tellina angulata from the Bombay coast

    Digital Repository Service at National Institute of Oceanography (India)

    Krishnakumari, L.; Nair, V.R.; Moraes, C.

    Metal content was determined in three groups of molluscs - an oyster Saccostrea cucullata, snail Cerithium rubus and clam Tellina angulata from three sites along the Bombay Coast. Seasonal difference in copper content was significant in S. cucullata...

  16. A one-step green route to synthesize copper nanocrystals and their applications in catalysis and surface enhanced Raman scattering

    Science.gov (United States)

    Zhang, Pinhua; Sui, Yongming; Wang, Chao; Wang, Yingnan; Cui, Guangliang; Wang, Chunzhong; Liu, Bingbing; Zou, Bo

    2014-04-01

    A nontoxic, simple, inexpensive, and reproducible strategy, which meets the standard of green chemistry, is introduced for the synthesis of copper nanocrystals (Cu NCs) with olive oil as both reducing agent and capping agent. By changing the reaction parameters, the shape, size and surface structure of the Cu NCs can be well controlled. The obtained Cu nanocubes show excellent catalytic properties for the catalytic reduction of dyes and CO oxidation. Moreover, the prepared Cu nanocubes as substrates exhibit surface enhanced Raman scattering (SERS) activity for 4-mercaptopyridine (4-Mpy). Therefore, this facile route provides a useful platform for the fabrication of Cu NCs which have the potential to replace noble metals for certain applications.A nontoxic, simple, inexpensive, and reproducible strategy, which meets the standard of green chemistry, is introduced for the synthesis of copper nanocrystals (Cu NCs) with olive oil as both reducing agent and capping agent. By changing the reaction parameters, the shape, size and surface structure of the Cu NCs can be well controlled. The obtained Cu nanocubes show excellent catalytic properties for the catalytic reduction of dyes and CO oxidation. Moreover, the prepared Cu nanocubes as substrates exhibit surface enhanced Raman scattering (SERS) activity for 4-mercaptopyridine (4-Mpy). Therefore, this facile route provides a useful platform for the fabrication of Cu NCs which have the potential to replace noble metals for certain applications. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr00412d

  17. Enhancement of photocathodic stability of p-type copper(I) oxide electrodes by surface etching treatment

    Energy Technology Data Exchange (ETDEWEB)

    Amano, Fumiaki, E-mail: amano@kitakyu-u.ac.jp [Catalysis Research Center, Hokkaido University, Sapporo 001-0021 (Japan); Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Department of Chemical and Environmental Engineering, The University of Kitakyushu, Kitakyushu 808-0135 (Japan); Ebina, Toshihiro [Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan); Ohtani, Bunsho [Catalysis Research Center, Hokkaido University, Sapporo 001-0021 (Japan); Graduate School of Environmental Science, Hokkaido University, Sapporo 060-0810 (Japan)

    2014-01-01

    The photoelectrochemical properties of electrodeposited p-type copper(I) oxide (Cu{sub 2}O) films were investigated using methyl viologen (MV{sup 2+}) as an electron acceptor. The pristine Cu{sub 2}O films were deactivated during the photocathodic reaction as a result of self-reduction, whereas the (111)-oriented Cu{sub 2}O films treated in an aqueous solution containing hexamethylenetetramine at pH 5 and 90 °C exhibited stable photocurrent for MV{sup 2+} reduction into the cation radical. Scanning electron microscope images showed that the treated films contained smaller crystal grains than untreated ones. X-ray photoelectron spectroscopy revealed that the treatment etched the thin layer of copper(II) oxide from the Cu{sub 2}O polycrystalline surface. Etching of the film surface enhanced the stability and steady-state photocurrent for photocathodic reduction of MV{sup 2+}, suggesting that the crystalline composition and structures exposed on the outermost surface of Cu{sub 2}O polycrystalline films have a considerable influence on the selectivity for the photocathodic reaction over self-reduction. - Highlights: • Photoelectrochemical reduction of methyl viologen by (111)-oriented Cu{sub 2}O thin films • Cu{sub 2}O films are etched using an aqueous solution containing hexamethylenetetramine. • Etching decreases crystal grain size and removes the thin layer of CuO. • Etching enhances the stability of Cu{sub 2}O photoelectrodes.

  18. Computer simulation of normal and pathological copper metabolism in man.

    Science.gov (United States)

    Blincoe, C

    1993-01-01

    A digital computer simulation of copper metabolism was used to simulate human copper metabolism. The simulation agrees well with the normal data extant. Wilson's disease (hepatolenticular degeneration) and Menkes' disease (steely-hair syndrome) were simulated. Simulation of the unavailability of accumulated liver copper simulated Wilson's disease if it was assumed that the increased urinary excretion was due to induction of an enzymic mechanism for enhanced excretion. This would be consistent with the genetic defect causing only the sequestering of unavailable copper in the liver. Other genetic defects need not be present. Menkes' disease is also a genetic disease affecting the newborn. It was simulated successfully as a defect in absorption of copper from the gastrointestinal tract.

  19. Enhancement of the spin accumulation at the interface between a spin-polarized tunnel junction and a semiconductor.

    Science.gov (United States)

    Tran, M; Jaffrès, H; Deranlot, C; George, J-M; Fert, A; Miard, A; Lemaître, A

    2009-01-23

    We report on spin injection experiments at a Co/Al2O3/GaAs interface with electrical detection. The application of a transverse magnetic field induces a large voltage drop DeltaV at the interface as high as 1.2 mV for a current density of 0.34 nA.microm(-2). This represents a dramatic increase of the spin accumulation signal, well above the theoretical predictions for spin injection through a ferromagnet/semiconductor interface. Such an enhancement is consistent with a sequential tunneling process via localized states located in the vicinity of the Al2O3/GaAs interface. For spin-polarized carriers these states act as an accumulation layer where the spin lifetime is large. A model taking into account the spin lifetime and the escape tunneling time for carriers traveling back into the ferromagnetic contact reproduces accurately the experimental results.

  20. Interfacial bonding enhancement of reel-to-reel selective electrodeposition of copper stabilizer on a multifilamentary second-generation high-temperature superconductor tape

    Science.gov (United States)

    Cai, Xinwei; Li, Wei; Bose, Anima; Selvamanickam, Venkat

    2016-10-01

    A reel-to-reel copper selective electrodeposition process over a multifilamentary second-generation high-temperature superconductor (2G-HTS) has been demonstrated in our previous work. If the interfacial bonding between the deposited copper layer and the underlying silver overlayer is weak, it might lead to delamination in applications including magnets, motors and generators. In this study, two approaches have been used to improve the copper-silver bonding without the degradation of superconductor performance. The first approach is acidifying the electrolyte by adding sulfuric acid, by which the kinetics of copper electrodeposition is enhanced, resulting in finer microstructure at the copper-silver interface and thus, improved interfacial bonding strength. The second approach consists of blocking the electrolyte outflow at the entrance of the reel-to-reel electroplating cell, by which the occurrence of large copper seeds on the tape caused by the heavy turbulence flow is effectively prevented. With these two improvements together deployed in the process, the peeling strength between the copper and silver layers of the 2G-HTS tape has been improved from 2 N in 90° peeling and from 3.0 N in 180° peeling, without any degradation on the superconducting performance.

  1. Arabidopsis thaliana G2-LIKE FLAVONOID REGULATOR and BRASSINOSTEROID ENHANCED EXPRESSION1 are low-temperature regulators of flavonoid accumulation.

    Science.gov (United States)

    Petridis, Antonios; Döll, Stefanie; Nichelmann, Lars; Bilger, Wolfgang; Mock, Hans-Peter

    2016-08-01

    Flavonoid synthesis is predominantly regulated at the transcriptional level through the MYB-basic helix-loop-helix (bHLH)-WD40 (MBW) (MYB: transcription factor of the myeloblastosis protein family, WD40: tanscription factor with a short structural motif of 40 amino acids which terminates in an aspartic acid-tryptophan dipeptide) complex, and responds to both environmental and developmental stimuli. Although the developmental regulation of flavonoid accumulation in Arabidopsis thaliana has been examined in great detail, the response of the flavonoid synthesis pathway to abiotic stress (particularly low temperature) remains unclear. A screen of a Dissociation element (Ds) transposon-induced mutation collection identified two lines which exhibited an altered profile of phenylpropanoid accumulation following exposure to low-temperature stress. One of the mutated genes (BRASSINOSTEROID ENHANCED EXPRESSION1 (BEE1)) encoded a brassinosteroid enhanced expression transcription factor, while the other (G2-LIKE FLAVONOID REGULATOR (GFR)) encoded a G2-like flavonoid regulator. Phenylpropanoid-targeted analysis was performed using high-performance LC-MS, and gene expression analysis using quantitative reverse transcription-PCR. In both mutants, the accumulation of quercetins and scopolin was reduced under low-temperature growing conditions, whereas that of anthocyanin was increased. BEE1 and GFR were both shown to negatively regulate anthocyanin accumulation by inhibiting anthocyanin synthesis genes via the suppression of the bHLH (TRANSPARENT TESTA8 (TT8) and GLABROUS3 (GL3)) and/or the MYB (PRODUCTION OF ANTHOCYANIN PIGMENTS2 (PAP2)) components of the MBW complex. Our results provide new insight into the regulatory control of phenylpropanoid metabolism at low temperatures, and reveal that BEE1 and GFR act as important components of the signal transduction chain. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

  2. Enhanced performance of a wide-aperture copper vapour laser with hydrogen additive in neon buffer gas

    Indian Academy of Sciences (India)

    Bijendra Singh; V V Subramaniam; S R Daultabad; Ashim Chakraboty

    2010-11-01

    A wide-aperture copper vapour laser was demonstrated at ∼ 10 kHz rep-rate with hydrogen additive in its buffer gas. Maximum power in excess of ∼ 50 W (at 10 kHz) was achieved by adding 1.96% hydrogen to the neon buffer gas at 20 mbar total gas pressure. This increase in output power was about 70% as compared to ∼ 30 W achieved with pure neon at 5.5 kHz rep-rate. The 70% enhancement achieved was significantly higher than the maximum reported value of 50% so far in the literature. The enhancement was much higher (about 150%) as compared to its 20 W power at 10 kHz rep-rate using pure neon as the standard CVL operation.

  3. Comparison of hyperthermia and adrenaline to enhance the intratumoral accumulation of cisplatin in a murin model of peritoneal carcinomatosis

    Directory of Open Access Journals (Sweden)

    Tixier Hervé

    2011-01-01

    Full Text Available Abstract Background The best method to deliver intraperitoneal chemotherapy (IPC for peritoneal carcinomatosis from ovarian cancer is not well defined. The aim of this study was to assess the ability of hyperthermia and adrenaline to enhance the intratumoral accumulation of cisplatin in a rat model of peritoneal carcinomatosis. Methods Four groups of 5 BDIX rats with ovarian peritoneal carcinomatosis underwent IPC with 30 mg/l of cisplatin according to the following conditions: normothermia at 37° for 1 or 2 hours, hyperthermia at 42°C for 1 hour or normothermia at 37°C for 2 hours with 2 mg/l adrenaline. Tissue platinum content was measured by atomic absorption spectroscopy. The effect of hyperthermia, adrenaline and the duration of exposure to the drug was measured in vivo (tissue concentration of platinum in tumor, abdominal and extra abdominal tissues and in vitro (cytotoxicity on human ovarian cancer cells. Results In vitro, hyperthermia and longer exposure enhanced the accumulation and the cytotoxic effect of cisplatin on cancer cells. In vivo, only the 2 hours treatment with adrenaline resulted in increased platinum concentrations. The rats treated with adrenaline showed significantly lower concentrations of cisplatin in extra peritoneal tissues than those treated with hyperthermia. Conclusion Adrenaline is more effective than hyperthermia in order to enhance the intratumoral concentration of cisplatin in rats with peritoneal carcinomatosis from ovarian origin. It may also decrease the systemic absorption of the drug.

  4. Coping with copper

    DEFF Research Database (Denmark)

    Nunes, Ines; Jacquiod, Samuel; Brejnrod, Asker

    2016-01-01

    Copper has been intensively used in industry and agriculture since mid-18(th) century and is currently accumulating in soils. We investigated the diversity of potential active bacteria by 16S rRNA gene transcript amplicon sequencing in a temperate grassland soil subjected to century-long exposure......, suggesting a potential promising role as bioindicators of copper contamination in soils....

  5. Natural variants of AtHKT1 enhance Na+ accumulation in two wild populations of Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Ana Rus

    2006-12-01

    Full Text Available Plants are sessile and therefore have developed mechanisms to adapt to their environment, including the soil mineral nutrient composition. Ionomics is a developing functional genomic strategy designed to rapidly identify the genes and gene networks involved in regulating how plants acquire and accumulate these mineral nutrients from the soil. Here, we report on the coupling of high-throughput elemental profiling of shoot tissue from various Arabidopsis accessions with DNA microarray-based bulk segregant analysis and reverse genetics, for the rapid identification of genes from wild populations of Arabidopsis that are involved in regulating how plants acquire and accumulate Na(+ from the soil. Elemental profiling of shoot tissue from 12 different Arabidopsis accessions revealed that two coastal populations of Arabidopsis collected from Tossa del Mar, Spain, and Tsu, Japan (Ts-1 and Tsu-1, respectively, accumulate higher shoot levels of Na(+ than do Col-0 and other accessions. We identify AtHKT1, known to encode a Na(+ transporter, as being the causal locus driving elevated shoot Na(+ in both Ts-1 and Tsu-1. Furthermore, we establish that a deletion in a tandem repeat sequence approximately 5 kb upstream of AtHKT1 is responsible for the reduced root expression of AtHKT1 observed in these accessions. Reciprocal grafting experiments establish that this loss of AtHKT1 expression in roots is responsible for elevated shoot Na(+. Interestingly, and in contrast to the hkt1-1 null mutant, under NaCl stress conditions, this novel AtHKT1 allele not only does not confer NaCl sensitivity but also cosegregates with elevated NaCl tolerance. We also present all our elemental profiling data in a new open access ionomics database, the Purdue Ionomics Information Management System (PiiMS; http://www.purdue.edu/dp/ionomics. Using DNA microarray-based genotyping has allowed us to rapidly identify AtHKT1 as the casual locus driving the natural variation in shoot Na

  6. Copper oxide nano-fluid stabilized by ionic liquid for enhancing thermal conductivity of reservoir formation: Applicable for thermal Enhanced Oil Recovery processes

    Directory of Open Access Journals (Sweden)

    Barahoei M.

    2016-01-01

    Full Text Available Since the oil reservoirs are limited and energy demand is increasing, seeking for high efficient EOR processes or enhancing the efficiency of current proposed EOR methods for producing trapped oil from reservoirs are highly investigated. As a way out, it is possible to couple the EOR and nanotechnology to utilize the efficiency of both methods together. Regarding this possibility, in the current study, in the first stage of investigation stable and uniform water-based solution of nano size particles of copper oxide with different concentrations (0.01-0.05 M were prepared and then injected into the core samples. In the first stage, the effects of different surfactants respect to their concentrations was investigated. Then, different scenarios of using nano-fluid as a thermal conductivity modifier were examined. The obtained results clearly demonstrate that changing concentration of nano particles of copper oxide from 0.01 M to 0.05 M is able to enhance the thermal conductivity of rocks from 27 % to 48 % compared with the thermal conductivity of dry core.

  7. Rapamycin decreases DNA damage accumulation and enhances cell growth of WRN-deficient human fibroblasts.

    Science.gov (United States)

    Saha, Bidisha; Cypro, Alexander; Martin, George M; Oshima, Junko

    2014-06-01

    Werner syndrome (WS), caused by mutations at the WRN helicase gene, is a progeroid syndrome characterized by multiple features consistent with accelerated aging. Aberrant double-strand DNA damage repair leads to genomic instability and reduced replicative lifespan of somatic cells. We observed increased autophagy in WRN knockdown cells; this was further increased by short-term rapamycin treatment. Long-term rapamycin treatment resulted in improved growth rate, reduced accumulation of DNA damage foci and improved nuclear morphology; autophagy markers were reduced to near-normal levels, possibly due to clearance of damaged proteins. These data suggest that protein aggregation plays a role in the development of WS phenotypes and that the mammalian target of rapamycin complex 1 pathway is a potential therapeutic target of WS.

  8. Enhanced ionic conductivity of apatite-type lanthanum silicate electrolyte for IT-SOFCs through copper doping

    Science.gov (United States)

    Ding, Xifeng; Hua, Guixiang; Ding, Dong; Zhu, Wenliang; Wang, Hongjin

    2016-02-01

    Apatite-type Lanthanum silicate (LSO) is among the most promising electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs) owing to the high conductivity and low activation energy at lower temperature than traditional doped-zirconia electrolyte. The ionic conductivity as well as the sintering density of lanthanum silicate oxy-apatite, La10Si6-xCuxO27-δ (LSCO, 0 ≤ x ≤ 2), was effectively enhanced through a small amount of doped copper. The phase composition, relative density, ionic conductivity and thermal expansion behavior of La10Si6-xCuxO27-δ was systematically investigated by X-ray diffraction (XRD), Archimedes' drainage method, scanning electron microscope (SEM), electrochemical impedance spectra (EIS) and thermal dilatometer techniques. With increasing copper doping content, the ionic conductivity of La10Si6-xCuxO27-δincreased, reaching a maximum of 4.8 × 10-2 S cm-1 at 800 °C for x = 1.5. The improved ionic conductivity could be primarily associated with the enhanced grain conductivity. The power output performance of NiO-LSCO/LSCO/LSCF single cell was superior to that obtained on NiO-LSO/LSO/LSCF at different temperatures using hydrogen as fuel and oxygen as oxidant, which could be attributed to the enhanced oxygen ionic conductivity as well as the sintering density for the copped doped lanthanum silicate. In conclusion, the apatite La10Si4.5Cu1.5O25.5 is a promising candidate electrolyte for IT-SOFCs.

  9. α-Naphthoflavone Increases Lipid Accumulation in Mature Adipocytes and Enhances Adipocyte-Stimulated Endothelial Tube Formation

    Directory of Open Access Journals (Sweden)

    Mei-Lin Wang

    2015-04-01

    Full Text Available The aryl hydrocarbon receptor (AhR is a ligand-activated factor that regulates biological effects associated with obesity. The AhR agonists, such as environmental contaminants 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD and β-naphthoflavone (BNF, inhibit preadipocyte differentiation and interfere with the functions of adipose tissue, whereas the antagonist may have opposite or protective effects in obesity. This study investigated the effects of α-naphthoflavone (α-NF, an AhR antagonist, on adipogenesis- and angiogenesis-associated factors in mature adipocytes and on cross-talk of mature adipocytes with endothelial cells (ECs. Besides, the roles of the AhR on lipid accumulation and on secretion of vascular endothelial growth factor were also determined by introducing siRNA of AhR. Differentiated 3T3-L1 cells were treated with α-naphthoflavone (α-NF (1–5 μM for 16 h. Lipid accumulation and the expressions of AhR-associated factors in the cells were determined. The interaction between adipocytes and ECs was investigated by cultivating ECs with conditioned medium (CM from α-NF-treated mature adipocytes, followed by the determination of endothelial tube formation. The results showed that α-NF significantly increased triglyceride (TG accumulation in mature adipocytes, which was associated with increased expression of hormone-sensitive lipase (HSL, estrogen receptor (ER, as well as decreased expression of AhR, AhR nuclear translocator (ARNT, cytochrome P4501B1 (CYP1B1, and nuclear factor erythroid-2-related factor (NRF-2 proteins. In addition, CM stimulated formation of tube-like structures in ECs, and α-NF further enhanced such stimulation in association with modulated the secretions of various angiogenic mediators by mature adipocytes. Similarly, increased TG accumulation and vascular endothelial growth factor (VEGF secretion were observed in AhR-knockout cells. In conclusion, α-NF increased TG accumulation in mature adipocytes and

  10. Eucommia ulmoides Oliver extract, aucubin, and geniposide enhance lysosomal activity to regulate ER stress and hepatic lipid accumulation.

    Directory of Open Access Journals (Sweden)

    Hwa-Young Lee

    Full Text Available Eucommia ulmoides Oliver is a natural product widely used as a dietary supplement and medicinal plant. Here, we examined the potential regulatory effects of Eucommia ulmoides Oliver extracts (EUE on hepatic dyslipidemia and its related mechanisms by in vitro and in vivo studies. EUE and its two active constituents, aucubin and geniposide, inhibited palmitate-induced endoplasmic reticulum (ER stress, reducing hepatic lipid accumulation through secretion of apolipoprotein B and associated triglycerides and cholesterol in human HepG2 hepatocytes. To determine how EUE diminishes the ER stress response, lysosomal and proteasomal protein degradation activities were analyzed. Although proteasomal activity was not affected, lysosomal enzyme activities including V-ATPase were significantly increased by EUE as well as aucubin and geniposide in HepG2 cells. Treatment with the V-ATPase inhibitor, bafilomycin, reversed the inhibition of ER stress, secretion of apolipoprotein B, and hepatic lipid accumulation induced by EUE or its component, aucubin or geniposide. In addition, EUE was determined to regulate hepatic dyslipidemia by enhancing lysosomal activity and to regulate ER stress in rats fed a high-fat diet. Together, these results suggest that EUE and its active components enhance lysosomal activity, resulting in decreased ER stress and hepatic dyslipidemia.

  11. Ultraviolet Radiation-Elicited Enhancement of Isoflavonoid Accumulation, Biosynthetic Gene Expression, and Antioxidant Activity in Astragalus membranaceus Hairy Root Cultures.

    Science.gov (United States)

    Jiao, Jiao; Gai, Qing-Yan; Wang, Wei; Luo, Meng; Gu, Cheng-Bo; Fu, Yu-Jie; Ma, Wei

    2015-09-23

    In this work, Astragalus membranaceus hairy root cultures (AMHRCs) were exposed to ultraviolet radiation (UV-A, UV-B, and UV-C) for promoting isoflavonoid accumulation. The optimum enhancement for isoflavonoid production was achieved in 34-day-old AMHRCs elicited by 86.4 kJ/m(2) of UV-B. The resulting isoflavonoid yield was 533.54 ± 13.61 μg/g dry weight (DW), which was 2.29-fold higher relative to control (232.93 ± 3.08 μg/g DW). UV-B up-regulated the transcriptional expressions of all investigated genes involved in isoflavonoid biosynthetic pathway. PAL and C4H were found to be two potential key genes that controlled isoflavonoid biosynthesis. Moreover, a significant increase was noted in antioxidant activity of extracts from UV-B-elicited AMHRCs (IC50 values = 0.85 and 1.08 mg/mL) in comparison with control (1.38 and 1.71 mg/mL). Overall, this study offered a feasible elicitation strategy to enhance isoflavonoid accumulation in AMHRCs and also provided a basis for metabolic engineering of isoflavonoid biosynthesis in the future.

  12. Massive Perched Ice Layers in the Shallow Firn of Greenland's Lower Accumulation Area Inhibit Percolation and Enhance Runoff

    Science.gov (United States)

    MacFerrin, M. J.; Machguth, H.; Charalampidis, C.; van As, D.; Abdalati, W.; Scambos, T. A.

    2014-12-01

    Greenland's recent trend of record-breaking melt seasons (2012, 2010, 2007, 2002, et al.) have substantially increased the amount of melt water generated in the ice sheet's lower accumulation area. Due to this enhanced refreezing in the firn, regions with low accumulation rates have formed multi-annual ice layers 5-10+ meters thick in the thermally active shallow firn that overlies porous firn at depth. The loss of pore space in the firn prevents the majority of melt water from percolating to depth and results in surface runoff where water previously would have refrozen. Here we present evidence from in situ ground-penetrating radar, firn cores and airborne radar from NASA's Operation IceBridge, collected both before and after Greenland's 2012 melt season, to illustrate the mechanism by which southwest Greenland's runoff zone in 2012 extended 20 kilometers inland from the long-term saturation line. Additional evidence from satellite imagery, firn temperature profiles and modeling support the notion that these layers blocked percolation and contributed to Greenland's record runoff in 2012. Should Greenland's trend of anomalously warm summers persist, these massive lenses are likely to grow thicker and extend further inland, resulting in enhanced runoff and rapid upslope migration of the equilibrium line. These results illustrate the vital importance of understanding subsurface firn changes in order to accurately predict Greenland's future runoff in a changing climate.

  13. Enhanced methylene blue oxidative removal by copper electrode-based plasma irradiation with the addition of hydrogen peroxide.

    Science.gov (United States)

    Son, Guntae; Kim, Do-Hyung; Lee, Jung Seok; Lee, Hongshin

    2016-08-01

    Submerged plasma irradiation (SPI)-based advanced oxidation processes have been studied for the oxidation of recalcitrant organic compounds because of their various physical and chemical properties. However, SPI technologies still have a few drawbacks such as relatively low efficiency for wastewater treatment and high energy consumption. In order to overcome these drawbacks, in this study, we proposed the combination of SPI and the Cu(II)-catalyzed Fenton-like system. The removal of methylene blue (MB) by the SPI system was significantly enhanced upon the addition of H2O2. The pseudo-first-order rate constants of MB removal increased with the increase of applied voltage. In addition, the optimum H2O2 dose and initial solution pH were 100 mM and 9, respectively. The reactive oxidants responsible for MB removal in copper electrode-based SPI/H2O2 systems are likely to be hydroxyl radicals (OH) or cupryl ion (Cu(III)), wherein Cu(III) is especially important. Furthermore, the copper electrode-based SPI/H2O2 system is a novel advanced oxidation process capable of oxidizing water recalcitrant and toxic organic pollutants at neutral pH.

  14. Use of ligand-modified micellar-enhanced ultrafiltration to selectively separate copper ions from wastewater streams

    Energy Technology Data Exchange (ETDEWEB)

    Shadizadeh, S.B.

    1992-12-31

    The selective removal of target ions from an aqueous solution containing ions of like charge by ligand-modified micellar-enhanced ultrafiltration (LM-MEUF), is presented. In LM-MEUF, surfactant and specially tailored ligand are added to the contaminated stream. The surfactant forms aggregates called micelles, the hydrocarbon core of which the ligand complexed with the target species will solubilize. The surfactant is chosen to have the same charge type as the target ion; therefore, other ions (with similar charge) will not associate with the micelle, which makes the separation of the target ion selective. The solution is then processed by ultrafiltration, using a membrane with pore size small enough to block the passage of the micelles. In this study the divalent copper is the target ion in the solution containing divalent calcium. The surfactant is cetylpyridinium chloride (CPC) and the ligand is 4-hexadecyloxybenzyliminodiacetic acid (C{sub 16}BIDA). Experiments were conducted with batch stirred cells and the results have been compared to separation that take place under a variety of conditions in the LM-MEUF process. Rejections of copper of up to 99.8% are observed, with almost no rejection of calcium, showing that LM-MEUF has excellent selectivity and separation efficiency.

  15. Copper inducing Aβ42 rather than Aβ40 nanoscale oligomer formation is the key process for Aβ neurotoxicity.

    Science.gov (United States)

    Jin, Lu; Wu, Wei-Hui; Li, Qiu-Ye; Zhao, Yu-Fen; Li, Yan-Mei

    2011-11-01

    Copper is known to be a critical factor in Alzheimer's disease (AD) pathogenesis, as it is involved in amyloid-β (Aβ) peptide related toxicity. However, the relationship between neurotoxicity and Aβ peptide in the presence of copper remains unclear. The effect of copper has not been clearly differentiated between Aβ42 and Aβ40, and it is still debated whether copper-mediated neurotoxicity is due to reactive oxygen species (ROS) accumulation or other molecular mechanisms. Here, we describe that copper dramatically affects Aβ42 aggregation and enhances Aβ42 cytotoxicity while it shows no significant effects on Aβ40. These phenomena are mainly because that the strong interactions between copper and Aβ42 lead to great conformation changes, and stabilize Aβ42 aggregates at highly toxic nanoscale oligomer stage, whereas copper shows no similar impact on Aβ40. We also propose a possible molecular mechanism that copper enhances Aβ42 cytotoxicity via perturbing membrane structure. Moreover, we test the effect of an analogue of copper, nickel, on Aβ aggregation and cytotoxicity, finding that nickel also enhances cytotoxicity via Aβ42 nanoscale oligomer formation. These results clarify that the copper-induced Aβ42 nanoscale oligomer formation is the key process for Aβ neurotoxicity, and suggest that disrupting the interactions between copper and Aβ42 peptide to inhibit nanoscale oligomerization process, deserves more attention in AD drug development.

  16. Endoplasmic reticulum-located PDAT1-2 from castor bean enhances hydroxy fatty acid accumulation in transgenic plants.

    Science.gov (United States)

    Kim, Hyun Uk; Lee, Kyeong-Ryeol; Go, Young Sam; Jung, Jin Hee; Suh, Mi-Chung; Kim, Jong Bum

    2011-06-01

    Ricinoleic acid (12-hydroxy-octadeca-9-enoic acid) is a major unusual fatty acid in castor oil. This hydroxy fatty acid is useful in industrial materials. This unusual fatty acid accumulates in triacylglycerol (TAG) in the seeds of the castor bean (Ricinus communis L.), even though it is synthesized in phospholipids, which indicates that the castor plant has an editing enzyme, which functions as a phospholipid:diacylglycerol acyltransferase (PDAT) that is specific to ricinoleic acid. Transgenic plants containing fatty acid Δ12-hydroxylase encoded by the castor bean FAH12 gene produce a limited amount of hydroxy fatty acid, a maximum of around 17% of TAGs present in Arabidopsis seeds, and this unusual fatty acid remains in phospholipids of cell membranes in seeds. Identification of ricinoleate-specific PDAT from castor bean and manipulation of the phospholipid editing system in transgenic plants will enhance accumulation of the hydroxy fatty acid in transgenic seeds. The castor plant has three PDAT genes; PDAT1-1 and PDAT2 are homologs of PDAT, which are commonly found in plants; however, PDAT1-2 is newly grouped as a castor bean-specific gene. PDAT1-2 is expressed in developing seeds and localized in the endoplasmic reticulum, similar to FAH12, indicating its involvement in conversion of ricinoleic acid into TAG. PDAT1-2 significantly enhances accumulation of total hydroxy fatty acid up to 25%, with a significant increase in castor-like oil, 2-OH TAG, in seeds of transgenic Arabidopsis, which is an identification of the key gene for oilseed engineering in production of unusual fatty acids.

  17. Exogenous Nitric Oxide Involved in Subcellular Distribution and Chemical Forms of Cu2+Under Copper Stress in Tomato Seedlings

    Institute of Scientific and Technical Information of China (English)

    DONG Yu-xiu; WANG Xiu-feng; CUI Xiu-min

    2013-01-01

    Nitric oxide (NO), a bioactive signaling molecule, serves as an antioxidant and anti-stress agent under abiotic stress. A hydroponics experiment was conducted to investigate the effects of sodium nitroprusside (SNP), a NO donor, on tomato seedlings exposed to 50 µmol L-1 CuCl2. The results show that copper is primarily stored in the soluble cell sap fraction in the roots, especially after treatment with Cu+SNP treatment, which accounted for 66.2%of the total copper content. The copper concentration gradually decreased from the roots to the leaves. In the leaves, exogenous NO induces the storage of excess copper in the cell walls. Copper stress decreases the proportion of copper integrated with pectates and proteins, but exogenous NO remarkably reverses this trend. The alleviating effect of NO is blocked by hemoglobin. Thus, exogenous NO is likely involved in the regulation of the subcellular copper concentrations and its chemical forms under copper stress. Although exogenous NO inhibited the absorption and transport of excess copper to some extent, the copper accumulation in tomato seedlings signiifcantly increased under copper stress. The use of exogenous NO to enhance copper tolerance in some plants is a promising method for copper remediation.

  18. Apolipoprotein O expression in mouse liver enhances hepatic lipid accumulation by impairing mitochondrial function.

    Science.gov (United States)

    Tian, Feng; Wu, Chen-Lu; Yu, Bi-Lian; Liu, Ling; Hu, Jia-Rui

    2017-09-09

    Apolipoprotein O (ApoO) was recently observed in the cellular mitochondrial inner membrane, which plays a role in mitochondrial function and is associated with myocardiopathy. Empirical information on the physiological functions of apoO is therefore limited. In this study, we aimed to elucidate the effect of apoO on hepatic fatty acid metabolism. An adenoviral vector expressing hApoO was constructed and introduced into chow diet and high-fat diet induced mice and the L02 human hepatoma cell line. High levels of hApoO mRNA and protein were detected in the liver, and the expression of lipid metabolism genes was significantly altered compared with negative controls. The liver function indices (serum ALT and AST) were clearly elevated, and the ultrastructure of cellular mitochondria was distinctly altered in the liver after apoO overexpression. Further, mitochondrial membrane potential decreased with hApoO treatment in L02 cells. These results establish a link between apoO and lipid accumulation and could suggest a new pathway for regulating non-alcoholic fatty liver disease progression. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Modern Breeding and Biotechnological Approaches to Enhance Carotenoid Accumulation in Seeds.

    Science.gov (United States)

    Federico, M L; Schmidt, M A

    There is an increasing demand for carotenoids, which are fundamental components of the human diet, for example as precursors of vitamin A. Carotenoids are also potent antioxidants and their health benefits are becoming increasingly evident. Protective effects against prostate cancer and age-related macular degeneration have been proposed for lycopene and lutein/zeaxanthin, respectively. Additionally, β-carotene, astaxanthin and canthaxanthin are high-value carotenoids used by the food industry as feed supplements and colorants. The production and consumption of these carotenoids from natural sources, especially from seeds, constitutes an important step towards fortifying the diet of malnourished people in developing nations. Therefore, attempts to metabolically manipulate β-carotene production in plants have received global attention, especially after the generation of Golden Rice (Oryza sativa). The endosperms of Golden Rice seeds synthesize and accumulate large quantities of β-carotene (provitamin A), yielding a characteristic yellow color in the polished grains. Classical breeding efforts have also focused in the development of cultivars with elevated seed carotenoid content, with maize and other cereals leading the way. In this communication we will summarize transgenic efforts and modern breeding strategies to fortify various crop seeds with nutraceutical carotenoids.

  20. Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation.

    Science.gov (United States)

    Chen, Liwei; Lee, Jaslyn Jie Lin; Zhang, Jianhua; Chen, Wei Ning

    2016-02-01

    The engineered Saccharomyces cerevisiae strain △faa1△faa4 [Acot5s] was demonstrated to accumulate more free fatty acids (FFA) previously. Here, comparative proteomic analysis was performed to get a global overview of metabolic regulation in the strain. Over 500 proteins were identified, and 82 of those proteins were found to change significantly in the engineered strains. Proteins involved in glycolysis, acetate metabolism, fatty acid synthesis, TCA cycle, glyoxylate cycle, the pentose phosphate pathway, respiration, transportation, and stress response were found to be upregulated in △faa1△faa4 [Acot5s] as compared to the wild type. On the other hand, proteins involved in glycerol, ethanol, ergosterol, and cell wall synthesis were downregulated. Taken together with our metabolite analysis, our results showed that the disruption of Faa1 and Faa4 and expression of Acot5s in the engineered strain △faa1△faa4 [Acot5s] not only relieved the feedback inhibition of fatty acyl-CoAs on fatty acid synthesis, but also caused a major metabolic rearrangement. The rearrangement redirected carbon flux toward the pathways which generate the essential substrates and cofactors for fatty acid synthesis, such as acetyl-CoA, ATP, and NADPH. Therefore, our results help shed light on the mechanism for the increased production of fatty acids in the engineered strains, which is useful in providing information for future studies in biofuel production.

  1. Enhanced arsenate reduction by a CDC25-like tyrosine phosphatase explains increased phytochelatin accumulation in arsenate-tolerant Holcus lanatus.

    Science.gov (United States)

    Bleeker, Petra M; Hakvoort, Henk W J; Bliek, Mattijs; Souer, Erik; Schat, Henk

    2006-03-01

    Decreased arsenate [As(V)] uptake is the major mechanism of naturally selected As(V) hypertolerance in plants. However, As(V)-hypertolerant ecotypes also show enhanced rates of phytochelatin (PC) accumulation, suggesting that improved sequestration might additionally contribute to the hypertolerance phenotype. Here, we show that enhanced PC-based sequestration in As(V)-hypertolerant Holcus lanatus is not due to an enhanced capacity for PC synthesis as such, but to increased As(V) reductase activity. Vacuolar transport of arsenite-thiol complexes was equal in both ecotypes. Based on homology with the yeast As(V) reductase, Acr2p, we identified a Cdc25-like plant candidate, HlAsr, and confirmed the As(V) reductase activity of both HlAsr and the homologous protein from Arabidopsis thaliana. The gene appeared to be As(V)-inducible and its expression was enhanced in the As(V)-hypertolerant H. lanatus ecotype, compared with the non-tolerant ecotype. Homologous ectopic overexpression of the AtASR cDNA in A. thaliana produced a dual phenotype. It improved tolerance to mildly toxic levels of As(V) exposure, but caused hypersensitivity to more toxic levels. Arabidopsis asr T-DNA mutants showed increased As(V) sensitivity at low exposure levels and enhanced arsenic retention in the root. It is argued that, next to decreased uptake, enhanced expression of HlASR might act as an additional determinant of As(V) hypertolerance and As transport in H. lanatus.

  2. Copper induction of enhanced green fluorescent protein expression in Pleurotus ostreatus driven by laccase poxa1b promoter.

    Science.gov (United States)

    Amore, Antonella; Honda, Yoichi; Faraco, Vincenza

    2012-12-01

    In silico analyses of several laccase promoter sequences have shown the presence of many different responsive elements differentially distributed along the promoter sequences. Analysis of Pleurotus ostreatus laccase promoter poxa1b extending around 1400-bp upstream of the start codon showed the presence of several putative response elements, such as 10 metal-responsive elements. Development of a system for in vivo analysis of P. ostreatus laccase promoter poxa1b by enhanced green fluorescent protein expression was carried out, based on a polyethylene glycol-mediated procedure for fungal transformation. Quantitative measurement of fluorescence expressed in P. ostreatus transformants grown in the presence and in the absence of copper sulfate was performed, demonstrating an increase in expression level induced by the metal.

  3. Experimental investigation of convective heat transfer enhancement using alumina/water and copper oxide/water nanofluids

    Directory of Open Access Journals (Sweden)

    Mangrulkar Chidanand K.

    2016-01-01

    Full Text Available The nanofluids are widely used for heat transfer applications in the various engineering applications. The nanoparticles dispersed uniformly in the base fluid on proper mixing. In the present study, Al2O3 and CuO nanoparticles were selected and the changes in the heat transfer coefficient were investigated in the complete laminar and discrete points of transition fluid flow through a copper tube with constant heat flux. The heat transfer coefficient was investigated at different loading of Al2O3 and CuO nanopowders ranging from 0.1% to 0.5% of volume concentration in each case for the laminar and transition fluid flow zones, which is then compared with the distilled water as a plain base fluid. It is found that the optimum enhancement in heat transfer is observed at relatively lower volume fraction of nanoparticles ranging between 0.2 to 0.3%.

  4. Scale-up cultivation enhanced arachidonic acid accumulation by red microalgae Porphyridium purpureum.

    Science.gov (United States)

    Chang, Jingyu; Le, Kai; Song, Xiaoqiang; Jiao, Kailin; Zeng, Xianhai; Ling, Xueping; Shi, Tuo; Tang, Xing; Sun, Yong; Lin, Lu

    2017-08-23

    The present study attempts to cultivate Porphyridium purpureum under different scale-up conditions for further development and commercialization of microalgae-derived PUFAs such as ARA and EPA. Different temperatures (25, 30, and 35 °C) and light intensities (70, 165, and 280 μmol/m(2)s) were applied to the 50 L pilot-scale cultivation of P. purpureum in ASW. The cultivation under the light intensity of 280 μmol/m(2)s at 35 °C obtained biomass concentration up to 9.52 g/L, total fatty acid content to 56.82 mg/g, and ARA content to 22.29 mg/g. While the maximum EPA content of 7.00 mg/g was achieved under the light intensity of 280 μmol/m(2)s at 25 °C and the highest ratio of UFAs to TFAs of 74.66% was also obtained in this trial. Both biomass concentration and TFAs content were improved by increasing light intensity and temperature. Moreover, the ratio of ARA to EPA was enhanced by increasing cultivation temperature under the light intensity of 280 μmol/m(2)s. In contrast with flask culture, the conversion of linoleic acid (C18:2) to ARA was enhanced in scale-up culture, leading to more ARA content. Phosphate limitation enhanced the synthesis of lipid and LPUFAs. Moreover, the biomass concentration and biosynthesis of palmitic acid were preferred by sufficient C (NaHCO3).

  5. Effect of the nitrogen status on copper accumulation and pools of metal-binding peptides in the planktonic diatom Thalassiosira pseudonana

    NARCIS (Netherlands)

    Rijstenbil, J.W.; Dehairs, F.; Ehrlich, R.; Wijnholds, J.A.

    1998-01-01

    Effects of the algal cellular nitrogen status on the defence against copper toxicity were studied in batch cultures of the coastal diatom Thalassiosira pseudonana, grown in coastal seawater (Oosterschelde, SW Netherlands; 30 parts per thousand salinity). The media represented nutrient-poor (summer)

  6. High-average-power high-beam-quality vis-UV sources based on kinetically enhanced copper vapor lasers

    Science.gov (United States)

    Brown, Daniel J. W.; Withford, Michael J.; Carman, Robert J.; Mildren, Richard P.; Piper, James A.

    2000-04-01

    Investigations of the factors that limit average power scaling of elemental copper vapor lasers (CVLs) have demonstrated that decay of the electron density in the interpulse period is critical in restricting pulse repetition rate and laser aperture scaling. We have recently developed the 'kinetic enhancement' (or KE) technique to overcome these limitations, whereby optimal plasma conditions are engineered using low concentrations of HCl/H2 additive gases in the Ne buffer. Dissociative electron attachment of HCl and subsequent mutual neutralization of Cl- and Cu+ promote rapid plasma relaxation and fast recovery of Cu densities, permitting operation at elevated Cu densities and pulse rates for given apertures. Using this approach, we have demonstrated increases in output power and efficiency of a factor of 2 or higher over conventional CVLs of the same size. For a 38 mm- bore KE-CVL, output powers up to 150 W have been achieved at 22 kHz, corresponding to record specific powers (80 mW/cm3) for such a 'small/medium-scale' device. In addition, kinetic enhancement significantly extends the gain duration and restores gain on-axis, even for high pulse rates, thereby promoting substantial increases (5 - 10x) in high- beam-quality power levels when operating with unstable resonators. This has enabled us to achieve much higher powers in second-harmonic generation from the visible copper laser output to the ultraviolet (e.g. 5 W at 255 nm from a small- scale KE-CVL). Our approach to developing KE-CVLs including computer modeling and experimental studies will be reviewed, and most recent results in pulse rate scaling and scaling of high-beam-quality power using oscillator-amplifier configurations, will be presented.

  7. Polyamine Accumulation in Transgenic Tomato Enhances the Tolerance to High Temperature Stress

    Institute of Scientific and Technical Information of China (English)

    Lin Cheng; Yijing Zou; Shuli Ding; Jiajing Zhang; Xiaolin Yu; Jiashu Cao; Gang Lu

    2009-01-01

    Polyamines play an important role in plant response to abiotic stress. S-adenosyl-I-methionine decarboxylase (SAMDC) is one of the key regulatory enzymes in the biosynthesis of polyamines. In order to better understand the effect of regulation of polyamine biosynthesis on the tolerance of high-temperature stress in tomato, SAMDC Cdna isolated from Saccharomyces cerevisiae was introduced into tomato genome by means of Agrobacterium tumefaciens through leaf disc transformation. Transgene and expression was confirmed by Southern and Northern blot analyses, respectively. Transgenic plants expressing yeast SAMDC produced 1.7- to 2.4-fold higher levels of spermidine and spermine than wild-type plants under high temperature stress, and enhanced antioxidant enzyme activity and the protection of membrane lipid peroxidation was also observed. This subsequently improved the efficiency of CO2 assimilation and protected the plants from high temperature stress, which indicated that the transgenic tomato presented an enhanced tolerance to high temperature stress (38℃) compared with wild-type plants, Our results demonstrated clearly that increasing polyamine biosynthesis in plants may be a means of creating high temperature-tolerant germplasm.

  8. Enhanced fatty acid oxidation in adipocytes and macrophages reduces lipid-induced triglyceride accumulation and inflammation.

    Science.gov (United States)

    Malandrino, Maria Ida; Fucho, Raquel; Weber, Minéia; Calderon-Dominguez, María; Mir, Joan Francesc; Valcarcel, Lorea; Escoté, Xavier; Gómez-Serrano, María; Peral, Belén; Salvadó, Laia; Fernández-Veledo, Sonia; Casals, Núria; Vázquez-Carrera, Manuel; Villarroya, Francesc; Vendrell, Joan J; Serra, Dolors; Herrero, Laura

    2015-05-01

    Lipid overload in obesity and type 2 diabetes is associated with adipocyte dysfunction, inflammation, macrophage infiltration, and decreased fatty acid oxidation (FAO). Here, we report that the expression of carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme in mitochondrial FAO, is higher in human adipose tissue macrophages than in adipocytes and that it is differentially expressed in visceral vs. subcutaneous adipose tissue in both an obese and a type 2 diabetes cohort. These observations led us to further investigate the potential role of CPT1A in adipocytes and macrophages. We expressed CPT1AM, a permanently active mutant form of CPT1A, in 3T3-L1 CARΔ1 adipocytes and RAW 264.7 macrophages through adenoviral infection. Enhanced FAO in palmitate-incubated adipocytes and macrophages reduced triglyceride content and inflammation, improved insulin sensitivity in adipocytes, and reduced endoplasmic reticulum stress and ROS damage in macrophages. We conclude that increasing FAO in adipocytes and macrophages improves palmitate-induced derangements. This indicates that enhancing FAO in metabolically relevant cells such as adipocytes and macrophages may be a promising strategy for the treatment of chronic inflammatory pathologies such as obesity and type 2 diabetes.

  9. Enhancement of antimicrobial activities of whole and sub-fractionated white tea by addition of copper (II sulphate and vitamin C against Staphylococcus aureus; a mechanistic approach

    Directory of Open Access Journals (Sweden)

    Holloway Andrew C

    2011-11-01

    Full Text Available Abstract Background Enhancement of antimicrobial plant products e.g. pomegranate extract by copper (II sulphate is known. Such combinations have applications in various settings, including the identification of novel compositions to study, treat and control infection. Methods A combination of white tea (WT (made allowing 10 minutes infusion time at 100°C was combined with 4.8 mM copper (II sulphate and tested for antimicrobial effect on the viability of Staphylococcus aureus NCTC 06571. Comparisons were made with green (GT and black (BT teas. A WT sub-fraction (WTF Results A 30 minute incubation at room temperature of copper (II sulphate alone and combined with WT reduced the viability of S. aureus NCTC 06571 by c.a 1 log10 cfu mL-1. GT and BT with copper (II sulphate negated activity to buffer values. Combined with copper (II sulphate, vitamin C, WTF and, vitamin C plus WTF all reduced the viability of S. aureus NCTC 06571 by c.a. 3.5 log10 cfu mL-1. Independent experiments showed the results were not due to pH effects. Adding WT or WTF to copper (II sulphate resulted in increased acidity. Copper (II sulphate alone and combined with WT required c.a 300 μg mL-1 (final concentration catalase to restore S. aureus viability, WTF with copper (II sulphate and added vitamin C required c.a 600 μg mL-1. WT and WTF UV-visible spectra were similar. Conclusions WT showed no efficacy in the combinations tested. WTF was enhanced with copper (II sulphate and further with vitamin C. WT and WTF increased acidity of copper (II sulphate possibly via the formation of chemical complexes. The difference in WT/WTF absorbance possibly represented substances less concentrated or absent in WTF. Investigations to establish which WTF component/s and in what proportions additives are most effective against target organisms are warranted.

  10. Copper Ion Accumulation in Litopenaeus Vannamei and the Effect on Metallothionein in Different Aquaculture Systems%铜离子在养殖对虾组织中的积累及其对金属硫蛋白含量的影响

    Institute of Scientific and Technical Information of China (English)

    李湘萍; 程波; 程江峰; 刘鹰

    2011-01-01

    为考察铜在循环水与静水养殖系统的凡纳滨对虾组织中的积累,本实验在两种养殖系统中分别添加硫酸铜,并使其浓度保持一致,经过92 d的培养,对铜在虾组织中的积累量进行了测定.结果表明,在两种系统中养殖的对虾,其组织中铜浓度依次为:肝胰t>鳃丝>甲壳>肌肉,肝胰腺中金属硫蛋白(MT)与肝胰腺中铜的积累有相似变化趋势.循环水系统与静水系统中虾肝胰腺和甲壳中铜的积累量有显著差异,而两种系统中虾鳃丝中铜的积累量差异不明显.%In order to study the accumulation of copper ion in shrimp of different aqua-culture systems, we added a certain concentration of sulfate copper in aquaculture systems and kept in the same level during the experiment. After 92 d, the accumulation of copper ion in different tissues and systems were analyzed. The copper accumulation in different tissues both in recirculating aquaculture system (RAS) and static aquaculture system (SAS) had the same accumulation currence: hepatopancreas > lamella > cara-pace> muscle. The concentration of metallothionein(MT) in hepatopancreas had the same change with the copper accumulation. The accumulation of copper in hepatopancreas and carapace in different aquaculture systems had significant difference, while copper ion in lamella changed insignificantly.

  11. Simulation of Bioleaching Heat Effects for Enhancement of Copper Recovery from Sarcheshmeh Chalcopyrite

    Science.gov (United States)

    Mahmoudian, Ali Reza; Sadrnezhaad, S. K.; Manafi, Zahra

    2014-08-01

    A heat-transfer model was formulated to determine the distribution of temperature within a bioheap of chalcopyrite of Sarcheshmeh copper mine. Bioleaching employs mixed mesophilic and thermophilic microbes for Cu extraction. Thermophiles are better than mesophiles to dissolve CuFeS2. The solution irrigation and aeration rates were taken into account as the main operational factors. The model was validated by comparing the temperature profiles of test columns with those of bioheap. The model was used to find the optimal ratio of irrigation to aeration. It was found that when the solution was fed at a flow rate of 5 kg/m2 h and air was blown at a flow rate of 7.5 kg/m2 h, the transition from a mesophilic to thermophilic state inside the heap was possible. In this situation, the maximum temperature rise inside the heap was about 332 K (59 °C) after 60 days.

  12. Graphene wrapped Copper Phthalocyanine nanotube: Enhanced photocatalytic activity for industrial waste water treatment

    Science.gov (United States)

    Mukherjee, Moumita; Ghorai, Uttam Kumar; Samanta, Madhupriya; Santra, Angshuman; Das, Gour P.; Chattopadhyay, Kalyan K.

    2017-10-01

    To improve the photocatalytic performance of metal phthalocyanine based catalyst, Copper Phthalocyanine (CuPc) functionalized reduced graphene oxide (RGO) nanocomposite has been synthesized through a simple chemical approach. The obtained product was characterized by X-ray diffraction technique (XRD), Fourier transform infrared (FTIR) spectroscopy, Ultraviolet-visible spectroscopy (UV-vis) and High resolution transmission electron microscopy (HRTEM). The photocatalytic activity of the RGO/CuPc nanocomposite was performed by the degradation of Rhodamine B (RhB) under visible light irradiation. The photocatalytic studies revealed that the RGO/CuPc nanocomposite exhibits much stronger catalytic behavior than the pristine CuPc nanotube. A plausible mechanism for the photodegradation of Rhodamine B (RhB) was suggested. The RGO wrapped CuPc nanotube composite materials offer great potential as active photocatalysts for degradation of organic pollutions in industrial waste water.

  13. Copper and Graphene activated ZnO nanopowders for enhanced photocatalytic and antibacterial activities

    Science.gov (United States)

    Ravichandran, K.; Chidhambaram, N.; Gobalakrishnan, S.

    2016-06-01

    ZnO, ZnO:Cu and ZnO:Cu:Graphene nanopowders were synthesized via a facile wet chemical method. The XRD studies show that the synthesized samples have hexagonal wurtzite structure. It is found that graphene addition induces a decrease in crystallite size. UV-vis absorption spectra of the samples show sharp absorption edges around 380 nm. Photoluminescence studies reveal that the incorporation of copper and graphene in ZnO facilitates the efficient photo generated electron-hole pair separation. It is found that the ZnO:Cu and ZnO:Cu:Graphene nanopowder exhibit improved photocatalytic efficiency for the photodegradation of Methylene Blue (MB) under visible light irradiation. Moreover, improved antibacterial activity of ZnO:Cu:Graphene nanopowder against Escherichia coli and Staphylococcus aureus bacteria is observed.

  14. The enhancement of benzotriazole on epoxy functionalized silica sol-gel coating for copper protection

    Science.gov (United States)

    Peng, Shusen; Zhao, Wenjie; Li, He; Zeng, Zhixiang; Xue, Qunji; Wu, Xuedong

    2013-07-01

    The influence of the amount of benzotriazole (BTA) on the wetting and anticorrosion ability of the epoxy functionalized silica sol-gel (ESol) coating was studied by various complementary methods. IR results demonstrate that BTA reacted with ESol through a 1:1 addition reaction of Nsbnd H to epoxy group. The water contact angle of the ESol coating increases with an increase in the amount of BTA. SEM and adhesion tests reveal that BTA could improve the adhesion of ESol to copper surface. Moreover, the best protection was achieved when the amount of BTA equals to the molar number of epoxy group in the ESol coating according to the results of electrochemical measurements and salt spray test.

  15. Nitrate reductase-mediated NO production enhances Cd accumulation in Panax notoginseng roots by affecting root cell wall properties.

    Science.gov (United States)

    Kan, Qi; Wu, Wenwei; Yu, Wenqian; Zhang, Jiarong; Xu, Jin; Rengel, Zed; Chen, Limei; Cui, Xiuming; Chen, Qi

    2016-04-01

    Panax notoginseng (Burk) F. H. Chen is a traditional medicinal herb in China. However, the high capacity of its roots to accumulate cadmium (Cd) poses a potential risk to human health. Although there is some evidence for the involvement of nitric oxide (NO) in mediating Cd toxicity, the origin of Cd-induced NO and its function in plant responses to Cd remain unknown. In this study, we examined NO synthesis and its role in Cd accumulation in P. notoginseng roots. Cd-induced NO production was significantly decreased by application of the nitrate reductase inhibitor tungstate but not the nitric oxide synthase inhibitor L-NAME (N(G)-methyl-l-arginine acetate), indicating that nitrate reductase is the major contributor to Cd-induced NO production in P. notoginseng roots. Under conditions of Cd stress, sodium nitroprusside (SNP, an NO donor) increased Cd accumulation in root cell walls but decreased Cd translocation to the shoot. In contrast, the NO scavenger cPTIO (2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide) and tungstate both significantly decreased NO-increased Cd retention in root cell walls. The amounts of hemicellulose 1 and pectin, together with pectin methylesterase activity, were increased with the addition of SNP but were decreased by cPTIO and tungstate. Furthermore, increases or decreases in hemicellulose 1 and pectin contents as well as pectin methylesterase activity fit well with the increased or decreased retention of Cd in the cell walls of P. notoginseng roots. The results suggest that nitrate reductase-mediated NO production enhances Cd retention in P. notoginseng roots by modulating the properties of the cell wall.

  16. Microautoradiographic Study of Rhodocyclus-Related Polyphosphate-Accumulating Bacteria in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Science.gov (United States)

    Kong, Yunhong; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2004-01-01

    The ecophysiology of uncultured Rhodocyclus-related polyphosphate-accumulating organisms (PAO) present in three full-scale enhanced biological phosphorus removal (EBPR) activated sludge plants was studied by using microautoradiography combined with fluorescence in situ hybridization. The investigations showed that these organisms were present in all plants examined and constituted 5 to 10, 10 to 15, and 17 to 22% of the community biomass. The behavior of these bacteria generally was consistent with the biochemical models proposed for PAO, based on studies of lab-scale investigations of enriched and often unknown PAO cultures. Rhodocyclus-related PAO were able to accumulate short-chain substrates, including acetate, propionate, and pyruvate, under anaerobic conditions, but they could not assimilate many other low-molecular-weight compounds, such as ethanol and butyrate. They were able to assimilate two substrates (e.g., acetate and propionate) simultaneously. Leucine and thymidine could not be assimilated as sole substrates and could only be assimilated as cosubstrates with acetate, perhaps serving as N sources. Glucose could not be assimilated by the Rhodocyclus-related PAO, but it was easily fermented in the sludge to products that were subsequently consumed. Glycolysis, and not the tricarboxylic acid cycle, was the source that provided the reducing power needed by the Rhodocyclus-related PAO to form the intracellular polyhydroxyalkanoate storage compounds during anaerobic substrate assimilation. The Rhodocyclus-related PAO were able to take up orthophosphate and accumulate polyphosphate when oxygen, nitrate, or nitrite was present as an electron acceptor. Furthermore, in the presence of acetate growth was sustained by using oxygen, as well as nitrate or nitrite, as an electron acceptor. This strongly indicates that Rhodocyclus-related PAO were able to denitrify and thus played a role in the denitrification occurring in full-scale EBPR plants. PMID:15345424

  17. Enhanced Raman spectroscopic study of the coordination chemistry of malononitrile on copper surfaces - Removal of nu(C=N) degeneracy through pi-coordination

    Science.gov (United States)

    Loo, B. H.; Lee, Y. G.; Frazier, D. O.

    1985-01-01

    Surface-enhanced Raman spectroscopy has been used to study the molecular interactions of malononitrile with copper electrode surfaces. The doubly degenerate CN stretching frequency at 2263/cm is removed when malononitrile adsorbs on copper. Two nu(CN) bands are observed at 2096 and 2204/cm at -0.6 V(SCE). The result shows that only one CN group is pi-coordinated with Cu, which contributes to the observed large shift (-167/cm) in nu(CN). The other CN group is not coordinated to the metal surface.

  18. Accumulation of Phase-Shift Nanoemulsions to Enhance MR-Guided Ultrasound-Mediated Tumor Ablation In Vivo

    Directory of Open Access Journals (Sweden)

    Jonathan A. Kopechek

    2013-01-01

    Full Text Available Magnetic resonance-guided high intensity focused ultrasound (MRgHIFU is being explored as a non-invasive technology to treat solid tumors. However, the clinical use of HIFU for tumor ablation applications is currently limited by the long treatment times required. Phase-shift nanoemulsions (PSNE, consisting of liquid perfluorocarbon droplets that can be vaporized into microbubbles, are being developed to accelerate HIFU-mediated heating. The purpose of this study was to examine accumulation of PSNE in intramuscular rabbit tumors in vivo. MR images were acquired before and after intravenous injection of gadolinium-containing PSNE. MR signal enhancement was observed in rabbit tumors up to six hours after injection, indicating that PSNE accumulated in the tumors. In addition, PSNE vaporization was detected in the tumor with B-mode ultrasound imaging, and MR thermometry measurements indicated that PSNE accelerated the rate of HIFU-mediated heating. These results suggest that PSNE could dramatically improve the efficiency and clinical feasibility of MRgHIFU.

  19. Enhanced photo- and antioxidative protection, and hydrogen peroxide accumulation in drought-stressed Cistus clusii and Cistus albidus plants.

    Science.gov (United States)

    Munné-Bosch, Sergi; Jubany-Marí, Tana; Alegre, Leonor

    2003-01-01

    Mechanisms of drought stress resistance were studied in Cistus clusii Dunal and Cistus albidus L., two native Mediterranean shrubs that can withstand severe summer drought. While water deficit, solar radiation and temperature increased from winter to summer in the field, C. clusii and C. albidus reduced leaf area, increased root mass per leaf area, and showed diurnal changes in stomatal conductance to minimize water loss. In both species, the consequent reductions in CO2 assimilation were accompanied by reduced efficiency of photosystem II photochemistry, and protection against stress was afforded by enhanced de-epoxidation of violaxanthin in the xanthophyll cycle and increases in alpha-tocopherol and beta-carotene. In addition, hydrogen peroxide (H2O2) accumulation was observed in mesophyll cell walls of both species during the first stages of drought, although no accumulation of H2O2 was observed in chloroplasts or other organelles during the study. Despite these common responses, C. albidus and C. clusii differed in the extent of photo- and antioxidative protection. In response to drought, C. clusii showed a higher de-epoxidation state of the xanthophyll cycle and higher alpha-tocopherol and beta-carotene concentrations than C. albidus. We conclude that several structural and biochemical mechanisms underlie stress resistance in C. clusii and C. albidus, and are indicative of the different degrees of stress resistance of these shrubs.

  20. Cell Wall Targeted in planta Iron Accumulation Enhances Biomass Conversion and Seed Iron Concentration in Arabidopsis and Rice

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haibing; Wei, Hui; Ma, Guojie; Antunes, Mauricio S.; Vogt, Stefan; Cox, Joseph; Zhang, Xiao; Liu, Xiping; Bu, Lintao; Gleber, S. Charlotte; Carpita, Nicholas C.; Makowski, Lee; Himmel, Michael E.; Tucker, Melvin P.; McCann, Maureen C.; Murphy, Angus S.; Peer, Wendy A.

    2016-10-01

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  1. Comparison of five different targeting ligands to enhance accumulation of liposomes into the brain.

    Science.gov (United States)

    van Rooy, Inge; Mastrobattista, Enrico; Storm, Gert; Hennink, Wim E; Schiffelers, Raymond M

    2011-02-28

    In many different studies nanocarriers modified with targeting ligands have been used to target to the brain. Many ligands have been successful, but it is difficult to compare results from different studies to determine which targeting ligand is the best. Therefore, we selected five targeting ligands (transferrin, RI7217, COG133, angiopep-2, and CRM197) and compared their ability to target liposomes to the brain in vitro and in vivo. In vitro, only CRM197-modified liposomes were able to bind to murine endothelial cells (bEnd.3). Both CRM197 and RI7217-modified liposomes associated with human endothelial cells (hCMEC/D3). In vivo, uptake of targeted liposomes was tested at 12h after iv injection. For some of the ligands, additional time points of 1 and 6h were tested. Only the RI7217 was able to significantly enhance brain uptake in vivo at all time points. Uptake in the brain capillaries was up to 10 times higher compared to untargeted liposomes, and uptake in the brain parenchyma was up to 4.3 times higher. Additionally, these results show that many targeting ligands that have been described for brain targeting, do not target to the brain in vivo when coupled to a liposomal delivery vehicle.

  2. Enhancing auxin accumulation in maize root tips improves root growth and dwarfs plant height.

    Science.gov (United States)

    Li, Zhaoxia; Zhang, Xinrui; Zhao, Yajie; Li, Yujie; Zhang, Guangfeng; Peng, Zhenghua; Zhang, Juren

    2017-05-12

    Maize is a globally important food, feed crop and raw material for the food and energy industry. Plant architecture optimization plays important roles in maize yield improvement. PIN-FORMED (PIN) proteins are important for regulating auxin spatiotemporal asymmetric distribution in multiple plant developmental processes. In this study, ZmPIN1a overexpression in maize increased the number of lateral roots and inhibited their elongation, forming a developed root system with longer seminal roots and denser lateral roots. ZmPIN1a overexpression reduced plant height, internode length and ear height. This modification of the maize phenotype increased the yield under high-density cultivation conditions, and the developed root system improved plant resistance to drought, lodging and a low-phosphate environment. IAA concentration, transport capacity determination and application of external IAA indicated that ZmPIN1a overexpression led to increased IAA transport from shoot to root. The increase in auxin in the root enabled the plant to allocate more carbohydrates to the roots, enhanced the growth of the root and improved plant resistance to environmental stress. These findings demonstrate that maize plant architecture can be improved by root breeding to create an ideal phenotype for further yield increases. © 2017 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

  3. Preferential accumulation and enhanced relative velocity of inertial droplets due to interactions with homogeneous isotropic turbulence

    Science.gov (United States)

    Bateson, Colin; Aliseda, Alberto

    2015-11-01

    We present results from wind tunnel experiments on the evolution of small inertial (d ~ 10 - 200 μm) water droplets in homogeneous, isotropic, slowly decaying grid turbulence. High-speed imaging and a Particle Tracking algorithm are used to calculate relative velocity distributions. We analyze the preferential concentration, via the 2D Radial Distribution Function, and enhanced relative velocity of droplets resulting from their inertial interactions with the underlying turbulence. The two-dimensional particle velocities, measured from multi-image tracks along a streamwise plane, are conditionally analyzed with respect to the distance from the nearest particle. We focus on the non-normality of the statistics for the particle-particle separation velocity component to examine the influence of the inertial interaction with the turbulence on the dynamics of the droplets. We observe a negative bias (in the mean and mode) in the separation velocity of particles for short separations, signaling a tendency of particles to collide more frequently than a random agitation by turbulence would predict. The tails of the distribution are interpreted in terms of the collision/coalescence process and the probability of collisions that do not lead to coalescence.

  4. Copper induced oxidative stresses, antioxidant responses and phytoremediation potential of Moso bamboo (Phyllostachys pubescens)

    Science.gov (United States)

    Chen, Junren; Shafi, Mohammad; Li, Song; Wang, Ying; Wu, Jiasen; Ye, Zhengqian; Peng, Danli; Yan, Wenbo; Liu, Dan

    2015-09-01

    Moso bamboo is recognized as phytoremediation plant due to production of huge biomass and high tolerance in stressed environment. Hydroponics and pot experiments were conducted to investigate mechanism of copper tolerance and to evaluate copper accumulation capacity of Moso bamboo. In hydroponics experiment there was non significant variation in MDA contents of leaves compared with control. SOD and POD initially indicated enhancing trend with application of 5 μM Cu and then decreased consistently with application of 25 and 100 μM Cu. Application of each additional increment of copper have constantly enhanced proline contents while maximum increase of proline was observed with application of 100 μM copper. In pot experiment chlorophyll and biomass initially showed increasing tendency and decreased gradually with application of each additional increment of Cu. Normal growth of Moso bamboo was observed with application of 100 mg kg-1 copper. However, additional application of 300 or 600 mg kg-1 copper had significantly inhibited growth of Moso bamboo. The concentration of Cu in Moso bamboo has attained the levels of 340, 60, 23 mg kg-1 in roots, stems and leaves respectively. The vacuoles were the main organs which accumulated copper and reduced toxicity of copper as studied by TEM-DEX technology.

  5. Accumulation of heavy metals and As in liver, hair, femur, and lung of Persian jird (Meriones persicus) in Darreh Zereshk copper mine, Iran.

    Science.gov (United States)

    Khazaee, Manoochehr; Hamidian, Amir Hossein; Alizadeh Shabani, Afshin; Ashrafi, Sohrab; Mirjalili, Seyyed Ali Ashghar; Esmaeilzadeh, Esmat

    2016-02-01

    Rodents frequently serve as bioindicator to monitor the quality of the environment. Concentrations of 11 elements (Cd, Co, Ti, Fe, Mn, Cu, Sb, As, Sr, Ni, and Cr) were investigated and compared in liver, hair, femur, and lung of the Persian jird (Meriones persicus) from Darreh Zereshk copper mine, Iran. Metals were determined in different tissues of 39 individuals of Persian jird, collected by snap trap in 2014 from five areas of Darreh Zereshk copper mine. Samples were prepared by wet digestion method, and the contents of elements were analyzed with ICP-OES (VARIAN, 725-ES) instrument. Cadmium, Sb, and Co were below the limit of detection, and Mn and As were found only in hair and liver tissues. We detected the highest concentration of Cu, As, Ti, Fe, Mn, Cr, and Ni in hair in comparison with other tissues. Significant higher levels of Ti in femur and hair; Fe in liver and hair; Mn in liver; As in hair; Sr in lung; Cr in lung, hair, femur, and liver; Cu in femur; and Ni in liver and lung tissues were observed in females. Nearly all element concentrations in the tissues of Persian jird from flotation site, Darreh Zereshk and Hasan Abad villages and leaching site (mining areas) were higher than those from tailing dump site (reference site). We found the highest concentrations of As in liver and hair; Ni and Cr in liver, hair, and lung; and Sr in lung and hair tissues of Persian jird in leaching site. We tried to specify the status of elements before fully exploitation of Darreh Zereshk copper mine by using bioindicator species. Based on our achievements, initial activities did not strongly pollute the surrounded environment of the mine. The high abundance of Persian jird as well as their several proper features makes them a suitable species for biomonitoring programs especially for further studies will be performed after full exploitation of Darreh Zereshk copper mine.

  6. Genetic Transformation of Artemisia carvifolia Buch with rol Genes Enhances Artemisinin Accumulation.

    Directory of Open Access Journals (Sweden)

    Erum Dilshad

    Full Text Available The potent antimalarial drug artemisinin has a high cost, since its only viable source to date is Artemisia annua (0.01-0.8% DW. There is therefore an urgent need to design new strategies to increase its production or to find alternative sources. In the current study, Artemisia carvifolia Buch was selected with the aim of detecting artemisinin and then enhancing the production of the target compound and its derivatives. These metabolites were determined by LC-MS in the shoots of A. carvifolia wild type plants at the following concentrations: artemisinin (8μg/g, artesunate (2.24μg/g, dihydroartemisinin (13.6μg/g and artemether (12.8μg/g. Genetic transformation of A. carvifolia was carried out with Agrobacterium tumefaciens GV3101 harboring the rol B and rol C genes. Artemisinin content increased 3-7-fold in transgenics bearing the rol B gene, and 2.3-6-fold in those with the rol C gene. A similar pattern was observed for artemisinin analogues. The dynamics of artemisinin content in transgenics and wild type A.carvifolia was also correlated with the expression of genes involved in its biosynthesis. Real time qPCR analysis revealed the differential expression of genes involved in artemisinin biosynthesis, i.e. those encoding amorpha-4, 11 diene synthase (ADS, cytochrome P450 (CYP71AV1, and aldehyde dehydrogenase 1 (ALDH1, with a relatively higher transcript level found in transgenics than in the wild type plant. Also, the gene related to trichome development and sesquiterpenoid biosynthesis (TFAR1 showed an altered expression in the transgenics compared to wild type A.carvifolia, which was in accordance with the trichome density of the respective plants. The trichome index was significantly higher in the rol B and rol C gene-expressing transgenics with an increased production of artemisinin, thereby demonstrating that the rol genes are effective inducers of plant secondary metabolism.

  7. Abnormal Copper Homeostasis: Mechanisms and Roles in Neurodegeneration

    OpenAIRE

    Mario Manto

    2014-01-01

    As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations at very low levels. Copper is a critical element for major neuronal functions, and the central nervous system is a major target of disorders of copper metabolism. Both the accumulation of copper and copper d...

  8. Enhancement of surface integrity of titanium alloy with copper by means of laser metal deposition process

    CSIR Research Space (South Africa)

    Erinosho, MF

    2016-04-01

    Full Text Available The laser metal deposition process possesses the combination of metallic powder and laser beam respectively. However, these combinations create an adhesive bonding that permanently solidifies the laser-enhanced-deposited powders. Titanium alloys (Ti...

  9. Heat transfer enhancement through inner grooved copper tubes with different tube parameters

    Directory of Open Access Journals (Sweden)

    M. M. Rahman, Y. M. Ling, G. W. Soon, G. A. Kuan

    2012-01-01

    Full Text Available This paper presents the evaluation of heat transfer coefficients for the flow of R22 through internally grooved copper tubes. A series of tests were conducted using two types of tubes namely Tube A and Tube B, which have different tube parameters. The straight and horizontal test section of the test apparatus with a length of 3.67 m was heated or cooled by water circulated in a surrounding annulus. Condensation tests were conducted at mass flux rates of 180 to 537 kg/m2s and the vapor qualities ranged from a nominal value of 83% at the test section inlet to 6% at the outlet. Evaporation tests were conducted at mass flux rates of 110 to 404 kg/m2s and the nominal vapor qualities at the inlet and outlet were 0 and 85%, respectively. For both the condensation and evaporation tests, the heat transfer coefficients are found to increase as the mass flux rate increases.

  10. Incorporation of Copper Enhances the Anti-Ageing Property of Flame-Sprayed High-Density Polyethylene Coatings

    Science.gov (United States)

    Jia, Zhengmei; Huang, Jing; Gong, Yongfeng; Jin, Peipeng; Suo, Xinkun; Li, Hua

    2017-02-01

    High-density polyethylene (HDPE)-copper (Cu) composite coatings were prepared through depositing HDPE-Cu core-shell particles by flame spraying. The HDPE-Cu composite coatings and the HDPE coatings were aged in xenon lamp ageing testing chamber. The variations of chemical compositions and surface morphology of the coatings before and after the ageing testing were analyzed using infrared spectroscopy, scanning electron microscopy, thermogravimetric analysis, differential scanning calorimetry and ultraviolet-visible spectrophotometer. Results show that there is no chemical composition variation in the HDPE-Cu coatings. Cracks were found on the surfaces of the HDPE coatings, while the HDPE-Cu coating shows almost intact surface morphology. These results suggest that the HDPE-Cu coatings present better anti-ageing performances than the HDPE coatings. Further assessment of the function of Cu shells on the anti-ageing property reveals that Cu shells not only enhanced the absorption of the coatings to ultraviolet, but also increased their reflectivity to visible light. Additionally, the Cu shells enhanced the decomposition temperature and thermal stability of HDPE in the composite coatings. These results give bright insight into potential anti-ageing applications of the polymer-based structures.

  11. Templating Sol-Gel Hematite Films with Sacrificial Copper Oxide: Enhancing Photoanode Performance with Nanostructure and Oxygen Vacancies.

    Science.gov (United States)

    Li, Yang; Guijarro, Néstor; Zhang, Xiaoli; Prévot, Mathieu S; Jeanbourquin, Xavier A; Sivula, Kevin; Chen, Hong; Li, Yongdan

    2015-08-12

    Nanostructuring hematite films is a critical step for enhancing photoelectrochemical performance by circumventing the intrinsic limitations on minority carrier transport. Herein, we present a novel sol-gel approach that affords nanostructured hematite films by including CuO as sacrificial templating agent. First, by annealing in air at 450 °C a film comprising an intimate mixture of CuO and Fe2O3 nanoparticles is obtained. The subsequent treatment with NaCl and annealing at 700 °C under Argon reveals a nanostructured highly crystalline hematite film devoid of copper. Photoelectrochemical investigations reveal that the incorporation of CuO as templating agent and the inert conditions employed during the annealing play a crucial role in the performance of the hematite electrodes. Mott-Schottky analysis shows a higher donor concentration when annealing in inert conditions, and even higher when combined with the NaCl treatment. These findings agree well with the presence of an oxygen-deficient shell on the material's surface evidenced by FT-IR and XPS measurements. Likewise, the incorporation of the CuO enhances the photocurrent obtained at 1.23 V from 0.55 to 0.8 mA·cm(-2) because of an improved nanostructure. Optimized films demonstrate an incident photon-to-current efficiency (IPCE) of 52% at 380 nm when applying 1.23 V versus RHE, and a faradaic efficiency for water splitting close to unity.

  12. Synthesis of silver particles on copper substrates using ethanol-based solution for surface-enhanced Raman spectroscopy

    Directory of Open Access Journals (Sweden)

    Li Chen

    2014-03-01

    Full Text Available The displacement reaction of AgNO3 and copper metal is an effective and economical way to fabricate Ag-Cu surface enhanced Raman scattering (SERS substrates. Aqueous solutions of AgNO3 are usually used for substrate preparation. In this work, a new method for Ag-Cu SERS substrate preparation is proposed, which uses an ethanol solution rather than an aqueous AgNO3 solution. Analysis of the surface morphologies of sample substrates by field emission scanning electron microscopy (FESEM showed that the silver nanoparticles prepared by this new method were more regular than those prepared in the traditional aqueous solution. The SERS spectra of Rhodamine 6G (R6G adsorbed on these Ag-Cu substrates were then investigated and compared. It was found that the Ag-Cu substrates prepared by this method provide significant improvements in Raman signal sensitivity and large-area uniformity. The enhancement factor of this new substrate is about 330 times higher than that prepared using an aqueous AgNO3 solution under identical experimental conditions. It was also found that 70% of the original sensitivity of the substrate remains after 15 days of exposure to air.

  13. Self-assembled monolayer of ammonium pyrrolidine dithiocarbamate on copper detected using electrochemical methods, surface enhanced Raman scattering and quantum chemistry calculations

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Q.-Q., E-mail: liaoqq1971@yahoo.com.cn [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Yue, Z.-W.; Yang, D. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Wang, Z.-H. [Department of Chemistry, Tongji University, Shanghai 200092 (China); Li, Z.-H. [Department of Chemistry, Fudan University, Shanghai 200433 (China); Ge, H.-H. [Key Lab of Shanghai Colleges and Universities for Electric Power Corrosion Control and Applied Electrochemistry, Shanghai Engineering Research Center of Energy-Saving in Heat Exchange Systems, Shanghai University of Electric Power, Shanghai 200090 (China); Li, Y.-J. [Department of Chemistry, Tongji University, Shanghai 200092 (China)

    2011-07-29

    Ammonium pyrrolidine dithiocarbamate (APDTC) monolayer was self-assembled on fresh copper surface obtained after oxidation-reduction cycle treatment in 0.1 mol L{sup -1} potassium chloride solution at ambient temperature. The APDTC self-assembled monolayer (SAM) on copper surface was investigated by surface enhanced Raman scattering spectroscopy and the results show that APDTC SAM is chemisorbed on copper surface by its sulfur atoms with perpendicular orientation. The optimum immersing period for SAM formation is 4 h at 0.01 mol L{sup -1} concentration of APDTC. The impedance results indicate that APDTC SAM has good corrosion inhibition effects for copper in 0.5 mol L{sup -1} hydrochloric acid solution and its maximum inhibition efficiency could reach 95%. Quantum chemical calculations show that APDTC has relatively small {Delta}E between the highest occupied molecular orbital and the lowest unoccupied molecular orbital and large negative charge in its two sulfur atoms, which facilitate formation of an insulating Cu/APDTC film on copper surface.

  14. Glycine propionyl-L-carnitine produces enhanced anaerobic work capacity with reduced lactate accumulation in resistance trained males

    Directory of Open Access Journals (Sweden)

    Orem Ihsan

    2009-04-01

    Full Text Available Abstract Background Recent research has indicated that short term administration of glycine propionyl-L-carnitine (GPLC significantly elevates levels of nitric oxide metabolites at rest and in response to reactive hyperaemia. However, no scientific evidence exists that suggests such supplementation enhances exercise performance in healthy, trained individuals. The purpose of this study was to examine the effects of GPLC on the performance of repeated high intensity stationary cycle sprints with limited recovery periods in resistance trained male subjects. Methods In a double-blind, placebo-controlled, cross-over design, twenty-four male resistance trained subjects (25.2 ± 3.6 years participated in two test sessions separated by one week. Testing was performed 90 minutes following oral ingestion of either 4.5 grams GPLC or 4.5 grams cellulose (PL, in randomized order. The exercise testing protocol consisted of five 10-second Wingate cycle sprints separated by 1-minute active recovery periods. Peak (PP and mean values (MP of sprint power output and percent decrement of power (DEC were determined per bout and standardized relative to body masss. Heart rate (HR and blood lactate (LAC were measured prior to, during and following the five sprint bouts. Results Significant main effects (p Conclusion These findings indicate that short-term oral supplementation of GPLC can enhance peak power production in resistance trained males with significantly less LAC accumulation.

  15. Copper and Cadmium Accumulation in Populations of Littorina saxatilis from the Isle of Man Having Differential Tolerance to Zinc and Lead

    Directory of Open Access Journals (Sweden)

    E.R. Daka

    2009-10-01

    Full Text Available The accumulation of Cu and Cd from solution was studied in Littorina saxatilis from five sitesaround the Isle of Man with different degrees of metal contamination. The winkles w ere exposed to increasingconcentrations of each metal (0, 0.01, 0.1, 0.5 and 1.0 mg LG1 added Cu and added Cd after acclimation tolaboratory conditions. The experimentation was conducted in triplicate runs and after the exposure period,tissue metal concentrations were determined by atomic absorption spectrophotometry. Different accumulationprofiles were observed for Cu and Cd. Cd accumulation was monotonic over the range of exposureconcentrations, giving linear regressions with high coefficients of determination. Cu accumulation on the otherhand was linear up to 0.5 mg LG1 but polynomial (quadratic fits described the accumulation patterns betterwhen all concentrations are included. Tissue Zn concentrations showed a significant relationship with Cdaccumulation. No significant interpopulation differences in Cu accumulation were shown by Analysis ofCovariance. Significant differences in Cd accumulation were found between populations although notreflective of the tolerance profile.

  16. Copper and dyes enhance laccase production in gamma-proteobacterium JB.

    Science.gov (United States)

    Malhotra, Kanam; Sharma, Prince; Capalash, Neena

    2004-07-01

    Laccase production in gamma-proteobacterium JB was enhanced 13-fold by adding 0.1 mM CuSO(4) 24 h after the onset of growth. Ethidium bromide (2.5 microM), Malachite Green, Phenol Red and Thymol Blue (10 microM each) enhanced laccase production 17-, 19-, 4- and 2-fold, respectively. Among the fourteen aromatic/organic compounds tried, p-aminobenzoic acid and an industrial effluent, from where the organism was isolated, showed 1.2- and 1.26-fold increases in production.

  17. [Copper metabolism and genetic disorders].

    Science.gov (United States)

    Shimizu, Norikazu

    2016-07-01

    Copper is one of essential trace elements. Copper deficiency lead to growth and developmental failure and/or neurological dysfunction. However, excess copper is also problems for human life. There are two disorders of inborn error of copper metabolism, Menkes disease and Wilson disease. Menkes disease is an X linked recessive disorder with copper deficiency and Wilson disease is an autosomal recessive disorder with copper accumulation. These both disorders result from the defective functioning of copper transport P-type ATPase, ATP7A of Menkes disease and ATP7B of Wilson disease. In this paper, the author describes about copper metabolism of human, and clinical feature, diagnosis and treatment of Menkes disease and Wilson disease.

  18. "Candidatus Propionivibrio aalborgensis": A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants.

    Science.gov (United States)

    Albertsen, Mads; McIlroy, Simon J; Stokholm-Bjerregaard, Mikkel; Karst, Søren M; Nielsen, Per H

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial "Candidatus Accumulibacter phosphatis" (Accumulibacter) and the model GAO being the gammaproteobacterial "Candidatus Competibacter phosphatis". Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set.

  19. “Candidatus Propionivibrio aalborgensis”: A Novel Glycogen Accumulating Organism Abundant in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Science.gov (United States)

    Albertsen, Mads; McIlroy, Simon J.; Stokholm-Bjerregaard, Mikkel; Karst, Søren M.; Nielsen, Per H.

    2016-01-01

    Enhanced biological phosphorus removal (EBPR) is widely used to remove phosphorus from wastewater. The process relies on polyphosphate accumulating organisms (PAOs) that are able to take up phosphorus in excess of what is needed for growth, whereby phosphorus can be removed from the wastewater by wasting the biomass. However, glycogen accumulating organisms (GAOs) may reduce the EBPR efficiency as they compete for substrates with PAOs, but do not store excessive amounts of polyphosphate. PAOs and GAOs are thought to be phylogenetically unrelated, with the model PAO being the betaproteobacterial “Candidatus Accumulibacter phosphatis” (Accumulibacter) and the model GAO being the gammaproteobacterial “Candidatus Competibacter phosphatis”. Here, we report the discovery of a GAO from the genus Propionivibrio, which is closely related to Accumulibacter. Propionivibrio sp. are targeted by the canonical fluorescence in situ hybridization probes used to target Accumulibacter (PAOmix), but do not store excessive amounts of polyphosphate in situ. A laboratory scale reactor, operated to enrich for PAOs, surprisingly contained co-dominant populations of Propionivibrio and Accumulibacter. Metagenomic sequencing of multiple time-points enabled recovery of near complete population genomes from both genera. Annotation of the Propionivibrio genome confirmed their potential for the GAO phenotype and a basic metabolic model is proposed for their metabolism in the EBPR environment. Using newly designed fluorescence in situ hybridization (FISH) probes, analyses of full-scale EBPR plants revealed that Propionivibrio is a common member of the community, constituting up to 3% of the biovolume. To avoid overestimation of Accumulibacter abundance in situ, we recommend the use of the FISH probe PAO651 instead of the commonly applied PAOmix probe set. PMID:27458436

  20. 大变形异步累积叠轧纯铜再结晶退火后的超细孪晶%Ultra-fine twins of large deformation asymmyetrical accumulative rolling bonding (AARB) pure copper after recrystalization annealing

    Institute of Scientific and Technical Information of China (English)

    周蕾; 史庆南; 刘润; 王军丽

    2012-01-01

    对纯铜带材进行异步累积叠轧大塑性变形,并辅以再结晶退火处理,制备出了均匀的超细孪晶铜材。利用透射电镜对变形铜材再结晶退火中形成的超细孪晶进行了观察。结果表明,大变形异步累积叠轧铜材在190℃下退火,变形铜材内发生孪晶形核,退火达到30min时,铜材内形成均匀的超细孪晶,大小为2~3μm;再结晶退火初期,电导率快速上升,随退火时间延长,电导率缓慢升高,最高达59MS/m。%Ultra-fine twins copper was prepared by asymmyetrical accumulative rolling bonding (AARB) and recrystalization annealing followed. The ultra-fine twins formed in deformed copper strips during recrystalization treatment was observed by TEM. The results show that twinning nucleation occurs in AARB copper when annealed at 190 ℃. Uniform uhra-fine twins forms when annaealed for 30 min, and the twin size is 2-3 μm. At the beginning of annealing, the electrical conductivity rises fast. With the extension of annealing time, the electrical conductivity rises slowly, and finally up to 59 MS/m.

  1. Effects on the accumulation of calcium, magnesium, iron, manganese, copper and zinc of adding the two inorganic forms of selenium to solution cultures of Zea mays.

    Science.gov (United States)

    Longchamp, M; Angeli, N; Castrec-Rouelle, M

    2016-01-01

    The addition of selenate or selenite to common fertilizers for crop production could be an effective way of producing selenium-rich food and feed. However, this would be feasible only if the increase in plant selenium (Se) content did not negatively influence the uptake of other essential elements. We therefore need to understand the interactions between Se and other major and trace elements during uptake by the plant. This study aimed to evaluate the influence of inorganic forms of Se on the accumulation of selected macronutrients (Ca and Mg) and micronutrients (Fe, Zn, Mn and Cu). Those essential elements are involved in the oxidative balance of cells. Zea mays seedlings were grown hydroponically in growth chambers in nutrient solutions to which we added 10, 50 or 1000 μg.L(-1) of selenate and/or selenite. Cation accumulation was significantly affected by the addition of 50 μg.L(-1) or 1000 μg.L(-1) Se, but not by the presence of 10 μg.L(-1) of Se in the nutrient solution. The highest concentration (1000 μg.L(-1)) of Se in the nutrient solution affected the accumulation of essential cations in Zea mays: selenate tended to increase the accumulation of Mg, Zn and Mn, whereas a selenate/selenite mixture tended to decrease the accumulation of Ca, Mg, Zn and Mn. Only Fe accumulation was unaffected by Se whatever its form or concentration. Selenium may also affect the distribution of cations on Zea mays. For example, levels of Mg and Zn translocation to the shoots were lower in the presence of selenite.

  2. Silver Adhesive Layer for Enhanced Pressure-Free Bonding Using Copper Nanoparticles

    Science.gov (United States)

    Satoh, Toshikazu; Ishizaki, Toshitaka; Akedo, Kunio

    2017-02-01

    Pressure-free Cu nanoparticle bonding between two Cu plates with an Ag adhesive layer was examined. Insertion of the Ag adhesive layer considerably enhanced the bonding strength at firing temperatures between 523 K and 673 K. The bonding strength generally increased with the firing temperature. The strength enhancement of the Ag adhesive layer was observed even for a very thin (3 nm) Ag layer, and there was no obvious dependence of the thickness of the Ag layer on the bonding strength for Ag layers of thickness up to 200 nm. Ag atoms from the adhesive layer diffused away to the bonding layer with an increase in the firing temperature. The elemental mapping images showed that the Ag had two morphologies: thin Ag layers existing between particulate Cu grains, and fine Ag particles dispersed in coarse Cu crystals. The microstructure near the interface between the Cu nanoparticle bonding layer and Cu plate used as the substrate suggests that the enhancement effect of the Ag layer originates in the active migration of the Ag layer itself.

  3. Enhancement of Pool Boiling Heat Transfer in Water Using Sintered Copper Microporous Coatings

    Directory of Open Access Journals (Sweden)

    Seongchul Jun

    2016-08-01

    Full Text Available Pool boiling heat transfer of water saturated at atmospheric pressure was investigated experimentally on Cu surfaces with high-temperature, thermally-conductive, microporous coatings (HTCMC. The coatings were created by sintering Cu powders on Cu surfaces in a nitrogen gas environment. A parametric study of the effects of particle size and coating thickness was conducted using three average particle sizes (APSs of 10 μm, 25 μm, and 67 μm and various coating thicknesses. It was found that nucleate boiling heat transfer (NBHT and critical heat flux (CHF were enhanced significantly for sintered microporous coatings. This is believed to have resulted from the random porous structures that appear to include reentrant type cavities. The maximum NBHT coefficient was measured to be approximately 400 kW/m2k with APS 67 μm and 296 μm coating thicknesses. This value is approximately eight times higher than that of a plain Cu surface. The maximum CHF observed was 2.1 MW/m2 at APS 67 μm and 428 μm coating thicknesses, which is approximately double the CHF of a plain Cu surface. The enhancement of NBHT and CHF appeared to increase as the particle size increased in the tested range. However, two larger particle sizes (25 μm and 67 μm showed a similar level of enhancement.

  4. Facile fabrication of novel porous graphitic carbon nitride/copper sulfide nanocomposites with enhanced visible light driven photocatalytic performance.

    Science.gov (United States)

    Chen, Xi; Li, Huankun; Wu, Yuxin; Wu, Hanshuo; Wu, Laidi; Tan, Pengfei; Pan, Jun; Xiong, Xiang

    2016-08-15

    In this work, a novel organic-inorganic heterostructured photocatalyst: porous graphitic carbon nitride (g-C3N4) hybrid with copper sulfide (CuS) had been synthesized via a precipitation-deposition method at low temperature for the first time. UV-vis spectroscopy revealed the porous g-C3N4/CuS nanocomposites showed a strong and broad visible light absorption. Furthermore, the g-C3N4/CuS nanocomposites showed higher photocatalytic activity in the photodegradation of various organic dyes than that of pure g-C3N4 and CuS, and the selected sample of g-C3N4/CuS-2 exhibited the best photocatalytic activity under visible light. The good photocatalytic activity could be ascribed to the matching of the g-C3N4 and CuS band gap energies. Besides, photoluminescent spectra and photoelectrochemical measurements also proved that the CuS/g-C3N4 could greatly enhance the charge generation and suppress the charge recombination of photogenerated carriers. According to the experimental result, a possible photocatalytic mechanism has been proposed. Due to the high stability, the porous g-C3N4/CuS could be applied in the field of environmental remediation. Our work highlights that coupling semiconductors with well-matched band energies provides a facile way to improve the photocatalytic activity.

  5. Enhanced accumulation of adipocytes in bone marrow stromal cells in the presence of increased extracellular and intracellular [Ca{sup 2+}

    Energy Technology Data Exchange (ETDEWEB)

    Hashimoto, Ryota, E-mail: hryota@juntendo.ac.jp [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Katoh, Youichi, E-mail: katoyo@juntendo-urayasu.jp [Institute for Environmental and Gender-Specific Medicine, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Nakamura, Kyoko [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Itoh, Seigo [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Iesaki, Takafumi [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Daida, Hiroyuki [Department of Cardiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan); Nakazato, Yuji [Institute for Environmental and Gender-Specific Medicine, Department of Cardiology, Juntendo University Faculty of Medicine Urayasu Hospital, Tomioka 2-1-1, Urayasu-shi, Chiba 279-0022 (Japan); Okada, Takao [Department of Physiology, Juntendo University Faculty of Medicine, Hongo 2-1-1, Bunkyo-ku, Tokyo 113-8421 (Japan)

    2012-07-13

    Highlights: Black-Right-Pointing-Pointer High [Ca{sup 2+}]{sub o} enhances adipocyte accumulation in the presence of adipogenic inducers. Black-Right-Pointing-Pointer High [Ca{sup 2+}]{sub o} enhances both proliferation and adipocyte differentiation in BMSCs. Black-Right-Pointing-Pointer High [Ca{sup 2+}]{sub o} induces an increase in [Ca{sup 2+}]{sub o} in BMSCs. Black-Right-Pointing-Pointer An intracellular Ca{sup 2+} chelator suppresses the enhancement in adipocyte accumulation. Black-Right-Pointing-Pointer Controlling [Ca{sup 2+}]{sub o} may govern the balance of adipocyte and osteoblast development. -- Abstract: The bone marrow stroma contains osteoblasts and adipocytes that have a common precursor: the pluripotent mesenchymal stem cell found in bone marrow stromal cells (BMSCs). Local bone marrow Ca{sup 2+} levels can reach high concentrations due to bone resorption, which is one of the notable features of the bone marrow stroma. Here, we describe the effects of high [Ca{sup 2+}]{sub o} on the accumulation of adipocytes in the bone marrow stroma. Using primary mouse BMSCs, we evaluated the level of adipocyte accumulation by measuring Oil Red O staining and glycerol-3-phosphate dehydrogenase (GPDH) activity. High [Ca{sup 2+}]{sub o} enhanced the accumulation of adipocytes following treatment with both insulin and dexamethasone together but not in the absence of this treatment. This enhanced accumulation was the result of both the accelerated proliferation of BMSCs and their differentiation into adipocytes. Using the fura-2 method, we also showed that high [Ca{sup 2+}]{sub o} induces an increase in [Ca{sup 2+}]{sub i}. An intracellular Ca{sup 2+} chelator suppressed the enhancement in adipocyte accumulation due to increased [Ca{sup 2+}]{sub o} in BMSCs. These data suggest a new role for extracellular Ca{sup 2+} in the bone marrow stroma: increased [Ca{sup 2+}]{sub o} induces an increase in [Ca{sup 2+}]{sub i} levels, which in turn enhances the accumulation of

  6. Disulfiram/copper-disulfiram Damages Multiple Protein Degradation and Turnover Pathways and Cytotoxicity is Enhanced by Metformin in Oesophageal Squamous Cell Carcinoma Cell Lines.

    Science.gov (United States)

    Jivan, Rupal; Damelin, Leonard Howard; Birkhead, Monica; Rousseau, Amanda Louise; Veale, Robin Bruce; Mavri-Damelin, Demetra

    2015-10-01

    Disulfiram (DSF), used since the 1950s in the treatment of alcoholism, is reductively activated to diethyldithiocarbamate and both compounds are thiol-reactive and readily complex copper. More recently DSF and copper-DSF (Cu-DSF) have been found to exhibit potent anticancer activity. We have previously shown that the anti-diabetic drug metformin is anti-proliferative and induces an intracellular reducing environment in oesophageal squamous cell carcinoma (OSCC) cell lines. Based on these observations, we investigated the effects of Cu-DSF and DSF, with and without metformin, in this present study. We found that Cu-DSF and DSF caused considerable cytotoxicity across a panel of OSCC cells, and metformin significantly enhanced the effects of DSF. Elevated copper transport contributes to DSF and metformin-DSF-induced cytotoxicity since the cell-impermeable copper chelator, bathocuproinedisulfonic acid, partially reversed the cytotoxic effects of these drugs, and interestingly, metformin-treated OSCC cells contained higher intracellular copper levels. Furthermore, DSF may target cancer cells preferentially due to their high dependence on protein degradation/turnover pathways, and we found that metformin further enhances the role of DSF as a proteasome inhibitor. We hypothesized that the lysosome could be an additional, novel, target of DSF. Indeed, this acid-labile compound decreased lysosomal acidification, and DSF-metformin co-treatment interfered with the progression of autophagy in these cells. In summary, this is the first such report identifying the lysosome as a target of DSF and based on the considerable cytotoxic effects of DSF either alone or in the presence of metformin, in vitro, and we propose these as novel potential chemotherapeutic approaches for OSCC.

  7. Enhanced triterpene accumulation in Panax ginseng hairy roots overexpressing mevalonate-5-pyrophosphate decarboxylase and farnesyl pyrophosphate synthase.

    Science.gov (United States)

    Kim, Yong-Kyoung; Kim, Yeon Bok; Uddin, Md Romij; Lee, Sanghyun; Kim, Soo-Un; Park, Sang Un

    2014-10-17

    To elucidate the function of mevalonate-5-pyrophosphate decarboxylase (MVD) and farnesyl pyrophosphate synthase (FPS) in triterpene biosynthesis, the genes governing the expression of these enzymes were transformed into Panax ginseng hairy roots. All the transgenic lines showed higher expression levels of PgMVD and PgFPS than that by the wild-type control. Among the hairy root lines transformed with PgMVD, M18 showed the highest level of transcription compared to the control (14.5-fold higher). Transcriptions of F11 and F20 transformed with PgFPS showed 11.1-fold higher level compared with control. In triterpene analysis, M25 of PgMVD produced 4.4-fold higher stigmasterol content (138.95 μg/100 mg, dry weight [DW]) than that by the control; F17 of PgFPS showed the highest total ginsenoside (36.42 mg/g DW) content, which was 2.4-fold higher compared with control. Our results indicate that metabolic engineering in P. ginseng was successfully achieved through Agrobacterium rhizogenes-mediated transformation and that the accumulation of phytosterols and ginsenosides was enhanced by introducing the PgMVD and PgFPS genes into the hairy roots of the plant. Our results suggest that PgMVD and PgFPS play an important role in the triterpene biosynthesis of P. ginseng.

  8. Impact of nitrite on aerobic phosphorus uptake by poly-phosphate accumulating organisms in enhanced biological phosphorus removal sludges.

    Science.gov (United States)

    Zeng, Wei; Li, Boxiao; Yang, Yingying; Wang, Xiangdong; Li, Lei; Peng, Yongzhen

    2014-02-01

    Impact of nitrite on aerobic phosphorus (P) uptake of poly-phosphate accumulating organisms (PAOs) in three different enhanced biological phosphorus removal (EBPR) systems was investigated, i.e., the enriched PAOs culture fed with synthetic wastewater, the two lab-scale sequencing batch reactors (SBRs) treating domestic wastewater for nutrient removal through nitrite-pathway nitritation and nitrate-pathway nitrification, respectively. Fluorescence in situ hybridization results showed that PAOs in the three sludges accounted for 72, 7.6 and 6.5% of bacteria, respectively. In the enriched PAOs culture, at free nitrous acid (FNA) concentration of 0.47 × 10(-3) mg HNO₂-N/L, aerobic P-uptake and oxidation of intercellular poly-β-hydroxyalkanoates were both inhibited. Denitrifying phosphorus removal under the aerobic conditions was observed, indicating the existence of PAOs using nitrite as electron acceptor in this culture. When the FNA concentration reached 2.25 × 10(-3) mg HNO2-N/L, denitrifying phosphorus removal was also inhibited. And the inhibition ceased once nitrite was exhausted. Corresponding to both SBRs treating domestic wastewater with nitritation and nitrification pathway, nitrite inhibition on aerobic P-uptake by PAOs did not occur even though FNA concentration reached 3 × 10(-3) and 2.13 × 10(-3) mg HNO₂-N/L, respectively. Therefore, PAOs taken from different EBPR activated sludges had different tolerance to nitrite.

  9. 'Candidatus Halomonas phosphatis', a novel polyphosphate-accumulating organism in full-scale enhanced biological phosphorus removal plants.

    Science.gov (United States)

    Nguyen, Hien Thi Thu; Nielsen, Jeppe Lund; Nielsen, Per Halkjaer

    2012-10-01

    Microautoradiography combined with fluorescence in situ hybridization (MAR-FISH) was used to screen for potential polyphosphate-accumulating organisms (PAOs) in full-scale enhanced biological phosphorus removal (EBPR) plants. Clone library analyses and application of MAR-FISH using newly designed probes revealed that small rods related to uncultured Halomonas within the gammaproteobacterial family Halomonadaceae were actively involved in uptake of orthophosphate. Although deeply branched in the Gammaproteobacteria, they were not targeted by the gammaproteobacterial probe (GAM42a). A part of them were also not targeted with the general bacterial probes (EUBmix). They could take up short-chain fatty acids (e.g. acetate and propionate) and ethanol under both anaerobic and aerobic conditions. Polyhydroxyalkanoate storage was observed under anaerobic conditions. There was no indication of a denitrifying capability. A survey of the occurrence of these Halomonas-PAOs in 23 full-scale EBPR plants revealed that they made up 0.5-5.7% of all bacteria in the plants, and were often in higher abundance than the well-described PAOs 'Candidatus Accumulibacter phosphatis'. This indicates a potentially important role for these uncultured Halomonas bacteria in the EBPR process in full-scale plants and we propose to name them 'Candidatus Halomonas phosphatis'. © 2012 Society for Applied Microbiology and Blackwell Publishing Ltd.

  10. Overexpression of SlGMEs leads to ascorbate accumulation with enhanced oxidative stress, cold, and salt tolerance in tomato.

    Science.gov (United States)

    Zhang, Chanjuan; Liu, Junxia; Zhang, Yuyang; Cai, Xiaofeng; Gong, Pengjuan; Zhang, Junhong; Wang, Taotao; Li, Hanxia; Ye, Zhibiao

    2011-03-01

    GDP-Mannose 3',5'-epimerase (GME; EC 5.1.3.18) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (AsA) biosynthesis pathway in higher plants. In this study, two members of the GME gene family were isolated from tomato (Solanum lycopersicum). Both SlGME genes encode 376 amino acids and share a 92% similarity with each other. Semi-quantitative RT-PCR indicated that SlGME1 was constantly expressed in various tissues, whereas SlGME2 was differentially expressed in different tissues. Transient expression of fused SlGME1-GFP (green fluorescent protein) and SlGME2-GFP in onion cells revealed the cytoplasmic localisation of the two proteins. Transgenic plants over-expressing SlGME1 and SlGME2 exhibited a significant increase in total ascorbic acid in leaves and red fruits compared with wild-type plants. They also showed enhanced stress tolerance based on less chlorophyll content loss and membrane-lipid peroxidation under methyl viologen (paraquat) stress, higher survival rate under cold stress, and significantly higher seed germination rate, fresh weight, and root length under salt stress. The present study demonstrates that the overexpression of two members of the GME gene family resulted in increased ascorbate accumulation in tomato and improved tolerance to abiotic stresses.

  11. Coconut oil enhances tomato carotenoid tissue accumulation compared to safflower oil in the Mongolian gerbil ( Meriones unguiculatus ).

    Science.gov (United States)

    Conlon, Lauren E; King, Ryan D; Moran, Nancy E; Erdman, John W

    2012-08-29

    Evidence suggests that monounsaturated and polyunsaturated fats facilitate greater absorption of carotenoids than saturated fats. However, the comparison of consuming a polyunsaturated fat source versus a saturated fat source on tomato carotenoid bioaccumulation has not been examined. The goal of this study was to determine the influence of coconut oil and safflower oil on tomato carotenoid tissue accumulation in Mongolian gerbils ( Meriones unguiculatus ) fed a 20% fat diet. Coconut oil feeding increased carotenoid concentrations among many compartments including total carotenoids in the serum (p = 0.0003), adrenal glandular phytoene (p = 0.04), hepatic phytofluene (p = 0.0001), testicular all-trans-lycopene (p = 0.01), and cis-lycopene (p = 0.006) in the prostate-seminal vesicle complex compared to safflower oil. Safflower oil-fed gerbils had greater splenic lycopene concentrations (p = 0.006) compared to coconut oil-fed gerbils. Coconut oil feeding increased serum cholesterol (p = 0.0001) and decreased hepatic cholesterol (p = 0.0003) compared to safflower oil. In summary, coconut oil enhanced tissue uptake of tomato carotenoids to a greater degree than safflower oil. These results may have been due to the large proportion of medium-chain fatty acids in coconut oil, which might have caused a shift in cholesterol flux to favor extrahepatic carotenoid tissue deposition.

  12. Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides

    Directory of Open Access Journals (Sweden)

    David R. Brown

    2013-11-01

    Full Text Available While thermoelectric materials can be used for solid state cooling, waste heat recovery, and solar electricity generation, low values of the thermoelectric figure of merit, zT, have led to an efficiency too low for widespread use. Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu2Se over a broad (360–410 K temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K, and a similar but larger increase over a wider temperature range in the zT of Cu1.97Ag.03Se (almost 1.0 at 400 K. The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics.

  13. Characterization and Photocatalytic Activity of Enhanced Copper-Silica-Loaded Titania Prepared via Hydrothermal Method

    Directory of Open Access Journals (Sweden)

    Ramarao Poliah

    2011-01-01

    Full Text Available TiO2 nanopowder, loaded with SiO2 and Cu-SiO2, was prepared under both acidic and basic environments via the hydrothermal method. The morphology and structure of TiO2 were studied by XRD, TEM, and FT-IR. The photocatalytic activity of samples was studied by monitoring the degradation of methyl orange, using a UV-visible spectrophotometer. The effect of Ti/Si ratio, pH, and Cu2+ addition on the formation of TiO2 and its photocatalytic activity was investigated in detail. The results show that a large surface area and a high surface acidity were important factors to achieve good TiO2 performance. The presence of Ti-O-Si bonding enhanced surface acidity, which improved its ability to adsorb more hydroxyl radicals and increased its surface area. The addition of 0.1 mol% concentration of Cu2+ and 25 mol% SiO2 in TiO2 induced the formation of new states close to the conduction band, which narrowed the band gap energy and enhanced the photodegradation efficiency.

  14. Phase transition enhanced thermoelectric figure-of-merit in copper chalcogenides

    Science.gov (United States)

    Brown, David R.; Day, Tristan; Borup, Kasper A.; Christensen, Sebastian; Iversen, Bo B.; Snyder, G. Jeffrey

    2013-11-01

    While thermoelectric materials can be used for solid state cooling, waste heat recovery, and solar electricity generation, low values of the thermoelectric figure of merit, zT, have led to an efficiency too low for widespread use. Thermoelectric effects are characterized by the Seebeck coefficient or thermopower, which is related to the entropy associated with charge transport. For example, coupling spin entropy with the presence of charge carriers has enabled the enhancement of zT in cobalt oxides. We demonstrate that the coupling of a continuous phase transition to carrier transport in Cu2Se over a broad (360-410 K) temperature range results in a dramatic peak in thermopower, an increase in phonon and electron scattering, and a corresponding doubling of zT (to 0.7 at 406 K), and a similar but larger increase over a wider temperature range in the zT of Cu1.97Ag.03Se (almost 1.0 at 400 K). The use of structural entropy for enhanced thermopower could lead to new engineering approaches for thermoelectric materials with high zT and new green applications for thermoelectrics.

  15. Breakage of resistance to Cucumber mosaic virus by co-infection with Zucchini yellow mosaic virus: enhancement of CMV accumulation independent of symptom expression.

    Science.gov (United States)

    Wang, Y; Lee, K C; Gaba, V; Wong, S M; Palukaitis, P; Gal-On, A

    2004-02-01

    Resistance to the cucumovirus Cucumber mosaic virus (CMV) in cucumber cv. Delila was manifested as a very low level of accumulation of viral RNA and capsid protein, and an absence of CMV-induced symptoms. In addition, resistance was observed at the single cell level, with a reduction in accumulation of CMV RNAs, compared to accumulation in cells of the susceptible cucumber cv. Bet Alpha. Resistance to CMV in cv. Delila was broken by co-infection with the potyvirus Zucchini yellow mosaic virus (ZYMV). Resistance breakage in cv. Delila plants was manifested by an increase in the accumulation of (+) and (-) CMV RNA as well as CMV capsid protein, with no increase in the level of accumulation of ZYMV. Resistance breakage in the resistant cultivar by ZYMV also occurred at the single cell level. Thus, synergistic interactions known to occur between a potyvirus and a cucumovirus led to resistance breakage during a double infection. However, resistance breakage was not accompanied by an increase in disease symptoms beyond those induced by ZYMV itself. On co-inoculation with an asymptomatic variant of ZYMV-AG an enhancement of CMV infection occurred without disease manifestation. Consequently, intensification of viral RNA and capsid protein accumulation can occur without a corresponding increase in disease development, suggesting that different host genes regulate viral accumulation and disease development in the CMV-resistant cucumber plants.

  16. Synthesis and Characterization of Copper-Based Composites Reinforced by CuZrAlNiTi Amorphous Particles with Enhanced Mechanical Properties

    Directory of Open Access Journals (Sweden)

    Kinga Tomolya

    2017-03-01

    Full Text Available Novel amorphous/crystalline composites were developed combining the ductile copper matrix with hard CuZr-based amorphous powder. The amorphous powders of two compositions, Cu39.2Zr36All4.8Ni10Ti10 and Cu39.2Zr35.2Al5.6Ni10Ti10, produced by ball milling were used for reinforcement of the composites. Different mixing techniques, magnetic mixing, ultrasonic mixing and high-energy ball milling, were applied in order to create a homogenous mixture of the powders. The composites were produced by hot pressing under a purified argon atmosphere. Their microstructure, homogeneity and mechanical properties were investigated. It was observed that before hot pressing, minimal porosity had been obtained for the composite blended for 15 min by the ball-mill with a ball-to-powder ratio of 80:1. Its copper content was 50 wt %, which is the minimum to produce a compact composite. Reinforcing the copper by amorphous powders, the maximal compressive strength was enhanced to 490 MPa and 470 MPa, respectively, for the abovementioned composites. The yield strength of the copper due to reinforcement increased drastically from 150 MPa to 400 MPa and 420 MPa.

  17. Fabricating an enhanced stable superhydrophobic surface on copper plates by introducing a sintering process

    Science.gov (United States)

    Hu, Jinyi; Yuan, Wei; Yan, Zhiguo; Zhou, Bo; Tang, Yong; Li, Zongtao

    2015-11-01

    The superhydrophobic surface has the potential for use in functional applications. This study reports a novel method for coupling a sintering process with a traditional technique based on the solution-immersion method to prepare a stable superhydrophobic surface. The use of a sintering process aids in the enhancement of the adhesive strength and acid resistance of the surface structure. The advantage of using this method lies in its flexibility in regulating the processing parameters and functional behaviours. The influences of different processing parameters were experimentally investigated. The surface treated with a sintering process remains superhydrophobic with a contact angle of >150° after immersion in an acid solution for 120 h. The sintered surface maintains good integrity after experiencing ultrasonic vibration for 5 min. The results indicate that the sintering temperature must be optimized to increase the adhesive strength and maintain sufficient hydrophobicity. The modification time is an important factor related to the level of hydrophobicity.

  18. Copper catalysis for enhancement of cobalt leaching and acid utilization efficiency in microbial fuel cells.

    Science.gov (United States)

    Liu, Yaxuan; Shen, Jingya; Huang, Liping; Wu, Dan

    2013-11-15

    Enhancement of both cobalt leaching from LiCoO2 and acid utilization efficiency (AUE) in microbial fuel cells (MFCs) was successfully achieved by the addition of Cu(II). A dosage of 10mg/L Cu(II) improved both cobalt leaching up to 308% and AUE of 171% compared to the controls with no presence of Cu(II). The apparent activation energy of cobalt leaching catalyzed by Cu(II) in MFCs was only 11.8 kJ/mol. These results demonstrate cobalt leaching in MFCs using Cu(II) as a catalyst may be an effective strategy for cobalt recovery and recycle of spent Li-ion batteries, and the evidence of influence factors including solid/liquid ratio, temperature, and pH and solution conductivity can contribute to improving understanding of and optimizing cobalt leaching catalyzed by Cu(II) in MFCs.

  19. Delayed accumulation of intestinal coliform bacteria enhances life span and stress resistance in Caenorhabditis elegans fed respiratory deficient E. coli

    Directory of Open Access Journals (Sweden)

    Gomez Fernando

    2012-12-01

    Full Text Available Abstract Background Studies with the nematode model Caenorhabditis elegans have identified conserved biochemical pathways that act to modulate life span. Life span can also be influenced by the composition of the intestinal microbiome, and C. elegans life span can be dramatically influenced by its diet of Escherichia coli. Although C. elegans is typically fed the standard OP50 strain of E. coli, nematodes fed E. coli strains rendered respiratory deficient, either due to a lack coenzyme Q or the absence of ATP synthase, show significant life span extension. Here we explore the mechanisms accounting for the enhanced nematode life span in response to these diets. Results The intestinal load of E. coli was monitored by determination of worm-associated colony forming units (cfu/worm or coliform counts as a function of age. The presence of GFP-expressing E. coli in the worm intestine was also monitored by fluorescence microscopy. Worms fed the standard OP50 E. coli strain have high cfu and GFP-labeled bacteria in their guts at the L4 larval stage, and show saturated coliform counts by day five of adulthood. In contrast, nematodes fed diets of respiratory deficient E. coli lacking coenzyme Q lived significantly longer and failed to accumulate bacteria within the lumen at early ages. Animals fed bacteria deficient in complex V showed intermediate coliform numbers and were not quite as long-lived. The results indicate that respiratory deficient Q-less E. coli are effectively degraded in the early adult worm, either at the pharynx or within the intestine, and do not accumulate in the intestinal tract until day ten of adulthood. Conclusions The findings of this study suggest that the nematodes fed the respiratory deficient E. coli diet live longer because the delay in bacterial colonization of the gut subjects the worms to less stress compared to worms fed the OP50 E. coli diet. This work suggests that bacterial respiration can act as a virulence factor

  20. Distribution of Copper in Rats Submitted to Treatment With Copper Aspirinate

    OpenAIRE

    LIU, Weiping; Yang, Yikun; Xiong, Huizhou; Lu, Ying; Yang, Rong

    1998-01-01

    The distribution of copper in Sprague – Dawley rats following a three month oral administration of 0,10 or 50mg/kg copper aspirinate has been investigated. Metal content was determined by ICP – AES in blood, brain, kidney, liver, lung, spleen, and dejection. The results show that treatment with copper aspirinate did not cause accumulation of copper in rats and excess ingested copper was excreted through feces.

  1. Copper enhances amyloid-beta peptide neurotoxicity and non beta-aggregation: a series of experiments conducted upon copper-bound and copper-free amyloid-beta peptide.

    Science.gov (United States)

    Dai, Xueling; Sun, Yaxuan; Gao, Zhaolan; Jiang, Zhaofeng

    2010-05-01

    Alzheimer's disease is characterized by the abnormal aggregation of amyloid-beta peptide (Abeta) in extracellular deposits known as senile plaques. However, the nature of the toxic Abeta species and its precise mechanism of action remain unclear. Previous reports suggest that the histidine residues are involved in copper-Abeta interaction, by which resulting in the neurotoxicity of Abeta and free radical damage. Here, we employed a mutant Abeta (Abeta H13R) in which a histidine residue was replaced by arginine. Copper facilitated the precipitation of both wild-type and mutant Abeta in the spectrophotometric absorbance assay but suppressed beta-structure aggregates according to Thioflavine-T assay. Wild-type Abeta alone is more cytotoxic but produced less amount of H(2)O(2) than AbetaH13R-copper complexes, suggesting that Abeta-membrane interaction may also implicated in the pathologic progress. Abeta toxicity is in positive correlation to its competence to aggregate despite the aggregation is mainly composed of non-beta fibril substances. In short, these findings may provide further evidence on the role of copper in the pathogenesis of Alzheimer's disease.

  2. Citric Acid Enhanced Copper Removal by a Novel Multi-amines Decorated Resin

    Science.gov (United States)

    Ling, Chen; Liu, Fuqiang; Pei, Zhiguo; Zhang, Xiaopeng; Wei, Mengmeng; Zhang, Yanhong; Zheng, Lirong; Zhang, Jing; Li, Aimin; Xing, Baoshan

    2015-05-01

    Cu removal by a novel multi-amines decorated resin (PAMD) from wastewater in the absence or presence of citric acid (CA) was examined. Adsorption capacity of Cu onto PAMD markedly increased by 186% to 5.07 mmol/g in the presence of CA, up to 7 times of that onto four commercial resins under the same conditions. Preloaded and kinetic studies demonstrated adsorption of [Cu-CA] complex instead of CA site-bridging and variations of adsorbate species were qualitatively illustrated. The interaction configuration was further studied with ESI-MS, FTIR, XPS and XANES characterizations. The large enhancement of Cu adsorption in Cu-CA bi-solutes systems was attributed to mechanism change from single-site to dual-sites interaction in which cationic or neutral Cu species (Cu2+ and CuHL0) coordinated with neutral amine sites and anionic complex species (CuL- and Cu2L22-) directly interacted with protonated amine sites via electrostatic attraction, and the ratio of the two interactions was approximately 0.5 for the equimolar bi-solutes system. Moreover, commonly coexisting ions in wastewaters had no obvious effect on the superior performance of PAMD. Also, Cu and CA could be recovered completely with HCl. Therefore, PAMD has a great potential to efficiently remove heavy metal ions from wastewaters in the presence of organic acids.

  3. Overexpression of ZmIRT1 and ZmZIP3 Enhances Iron and Zinc Accumulation in Transgenic Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Suzhen Li

    Full Text Available Iron and zinc are important micronutrients for both the growth and nutrient availability of crop plants, and their absorption is tightly controlled by a metal uptake system. Zinc-regulated transporters, iron-regulated transporter-like proteins (ZIP, is considered an essential metal transporter for the acquisition of Fe and Zn in graminaceous plants. Several ZIPs have been identified in maize, although their physiological function remains unclear. In this report, ZmIRT1 was shown to be specifically expressed in silk and embryo, whereas ZmZIP3 was a leaf-specific gene. Both ZmIRT1 and ZmZIP3 were shown to be localized to the plasma membrane and endoplasmic reticulum. In addition, transgenic Arabidopsis plants overexpressing ZmIRT1 or ZmZIP3 were generated, and the metal contents in various tissues of transgenic and wild-type plants were examined based on ICP-OES and Zinpyr-1 staining. The Fe and Zn concentration increased in roots and seeds of ZmIRT1-overexpressing plants, while the Fe content in shoots decreased. Overexpressing ZmZIP3 enhanced Zn accumulation in the roots of transgenic plants, while that in shoots was repressed. In addition, the transgenic plants showed altered tolerance to various Fe and Zn conditions compared with wild-type plants. Furthermore, the genes associated with metal uptake were stimulated in ZmIRT1 transgenic plants, while those involved in intra- and inter- cellular translocation were suppressed. In conclusion, ZmIRT1 and ZmZIP3 are functional metal transporters with different ion selectivities. Ectopic overexpression of ZmIRT1 may stimulate endogenous Fe uptake mechanisms, which may facilitate metal uptake and homeostasis. Our results increase our understanding of the functions of ZIP family transporters in maize.

  4. Estradiol enhances effects of fructose rich diet on cardiac fatty acid transporter CD36 and triglycerides accumulation.

    Science.gov (United States)

    Korićanac, Goran; Tepavčević, Snežana; Romić, Snježana; Živković, Maja; Stojiljković, Mojca; Milosavljević, Tijana; Stanković, Aleksandra; Petković, Marijana; Kamčeva, Tina; Žakula, Zorica

    2012-11-05

    Fructose rich diet increases hepatic triglycerides production and has deleterious cardiac effects. Estrogens are involved in regulation of lipid metabolism as well, but their effects are cardio beneficial. In order to study effects of fructose rich diet on the main heart fatty acid transporter CD36 and the role of estrogens, we subjected ovariectomized female rats to the standard diet or fructose rich diet, with or without estradiol (E2) replacement. The following parameters were analyzed: feeding behavior, visceral adipose tissue mass, plasma lipids, cardiac CD36 expression, localization and insulin regulation, as well as the profile of cardiac lipids. Results show that fructose rich diet significantly increased plasma triglycerides and decreased plasma free fatty acid (FFA) concentration, while E2 additionally emphasized FFA decrease. The fructose diet increased cardiac plasma membrane content of CD36 in the basal and insulin-stimulated states, and decreased its low density microsomes content. The E2 in fructose-fed rats raised the total cardiac protein content of CD36, its presence in plasma membranes and low density microsomes, and cardiac deposition of triglycerides, as well. Although E2 counteracts fructose in some aspects of lipid metabolism, and separately they have opposite cardiac effects, in combination with fructose rich diet, E2 additionally enhances CD36 presence in plasma membranes of cardiac cells and triglycerides accumulation, which paradoxically might promote deleterious effects of fructose diet on cardiac lipid metabolism. Taken together, the results presented in this work are of high importance for clinical administration of estrogens in females with a history of type 2 diabetes.

  5. Identity and Ecophysiology of Uncultured Actinobacterial Polyphosphate-Accumulating Organisms in Full-Scale Enhanced Biological Phosphorus Removal Plants

    Science.gov (United States)

    Kong, Yunhong; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

    2005-01-01

    Microautoradiography combined with fluorescence in situ hybridization (MAR-FISH) was used to screen for potential polyphosphate-accumulating organisms (PAO) in a full-scale enhanced biological phosphorus removal (EBPR) plant. The results showed that, in addition to uncultured Rhodocyclus-related PAO, two morphotypes hybridizing with gene probes for the gram-positive Actinobacteria were also actively involved in uptake of orthophosphate (Pi). Clone library analysis and further investigations by MAR-FISH using two new oligonucleotide probes revealed that both morphotypes, cocci in clusters of tetrads and short rods in clumps, were relatively closely related to the genus Tetrasphaera within the family Intrasporangiaceae of the Actinobacteria (93 to 98% similarity in their 16S rRNA genes). FISH analysis of the community biomass in the treatment plant investigated showed that the short rods (targeted by probe Actino-658) were the most abundant (12% of all Bacteria hybridizing with general bacterial probes), while the cocci in tetrads (targeted by probe Actino-221) made up 7%. Both morphotypes took up Pi aerobically only if, in a previous anaerobic phase, they had taken up organic matter from wastewater or a mixture of amino acids. They could not take up short-chain fatty acids (e.g., acetate), glucose, or ethanol under anaerobic or aerobic conditions. The storage compound produced during the anaerobic period was not polyhydroxyalkanoates, as for Rhodocyclus-related PAO, and its identity is still unknown. Growth and uptake of Pi took place in the presence of oxygen and nitrate but not nitrite, indicating a lack of denitrifying ability. A survey of the occurrence of these actinobacterial PAO in 10 full-scale EBPR plants revealed that both morphotypes were widely present, and in several plants more abundant than the Rhodocyclus-related PAO, thus playing a very important role in the EBPR process. PMID:16000823

  6. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J|info:eu-repo/dai/nl/074236539; Fieten, Hille|info:eu-repo/dai/nl/314112596

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurolog

  7. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurolog

  8. Canine Models for Copper Homeostasis Disorders

    NARCIS (Netherlands)

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and

  9. Nitrogen-doped graphene network supported copper nanoparticles encapsulated with graphene shells for surface-enhanced Raman scattering

    Science.gov (United States)

    Zhang, Xiang; Shi, Chunsheng; Liu, Enzuo; Li, Jiajun; Zhao, Naiqin; He, Chunnian

    2015-10-01

    In this study, we demonstrated nitrogen-doped graphene network supported few-layered graphene shell encapsulated Cu nanoparticles (NPs) (Cu@G-NGNs) as a sensing platform, which were constructed by a simple and scalable in situ chemical vapor deposition (CVD) technique with the assistance of a self-assembled three-dimensional (3D) NaCl template. Compared with pure Cu NPs and graphene decorated Cu NPs, the graphene shells can strengthen the plasmonic coupling between graphene and Cu, thereby contributing to an obvious improvement in the local electromagnetic field that was validated by finite element numerical simulations, while the 3D nitrogen-doped graphene walls with a large surface area facilitated molecule adsorption and the doped nitrogen atoms embedded in the graphene lattice can reduce the surface energy of the system. With these merits, a good surface enhanced Raman spectroscopy (SERS) activity of the 3D Cu@G-NGN painting film on glass was demonstrated using rhodamine 6G and crystal violet as model analytes, exhibiting a satisfactory sensitivity, reproducibility and stability. As far as we know, this is the first report on the in situ synthesis of nitrogen-doped graphene/copper nanocomposites and this facile and low-cost Cu-based strategy tends to be a good supplement to Ag and Au based substrates for SERS applications.In this study, we demonstrated nitrogen-doped graphene network supported few-layered graphene shell encapsulated Cu nanoparticles (NPs) (Cu@G-NGNs) as a sensing platform, which were constructed by a simple and scalable in situ chemical vapor deposition (CVD) technique with the assistance of a self-assembled three-dimensional (3D) NaCl template. Compared with pure Cu NPs and graphene decorated Cu NPs, the graphene shells can strengthen the plasmonic coupling between graphene and Cu, thereby contributing to an obvious improvement in the local electromagnetic field that was validated by finite element numerical simulations, while the 3D nitrogen

  10. Ability of Agrogyron elongatum to accumulate the single metal of cadmium, copper, nickel and lead and root exudation of organic acids

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Agrogyron elongatum were grown in nutrient solution containing moderate to high amounts of separate heavy metal of Cd, Cu, Ni and Pb in a greenhouse for a 9-day. Cd, Cu, Ni and Pb generally led to decrease in the elongation of roots although the length of seedlings exposed to Cd and Pb at 0,05 and 0.5 mg/L showed to be slightly greater than that of controls. Of the four metals in the experiment, Pb was absorbed and accumulated to the highest level, with the concentrations of 92754 mg/kg dry weight (DW) in roots and 11683 mg/kg DW in shoots. Cd was moderately accumulated in Agrogyron elongatum, but the maximum bioaccumulation coefficients (BCs) for rpots and shoots were observed. The patterns for Cu and Ni uptake and distribution in plants differed from those of Pb and Cd, as it was showed that the shoot accumulation of Cu and Ni was significantly higher than in roots. A. elongatum had the highest Ni concentration in shoots (30261 mg/kg DW)at the external concentration of 250 mg/L. Cu ranked second, with a shoot concentration of 12230 mg/kg DW when 50 mg/L Cu in solution was applied. For the four trace elements tested, the highest concentrations in shoots decreased by the order of Ni > Cu > Pb > Cd (mg/kg DW),and those in roots were Pb > Cd > Ni > Cu (mg/kg DW). Malic, oxalic and citric acids exuded by roots exposed to 1 and 50 mg/L of the metals were detected. Release of organic acids from plants significantly differed among the metal treatments. Cu was most effectively in inducing rpot exudation of the three types of organic acids. Cd, and Ni were also the inducers of secretion of malic and oxalic acids. With reference of Pb,a small amounts of malic and oxalic acids were detected in the root exudates, but few quantities of citric acid were found. However, no orrelation between alternations in root exudation of organic acids and metal accumulation could be established.

  11. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Science.gov (United States)

    Kaiser, J.; Galiová, M.; Novotný, K.; Červenka, R.; Reale, L.; Novotný, J.; Liška, M.; Samek, O.; Kanický, V.; Hrdlička, A.; Stejskal, K.; Adam, V.; Kizek, R.

    2009-01-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 μm in a up to cm × cm area of sunflower ( Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  12. Mapping of lead, magnesium and copper accumulation in plant tissues by laser-induced breakdown spectroscopy and laser-ablation inductively coupled plasma mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Kaiser, J. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic)], E-mail: kaiser@fme.vutbr.cz; Galiova, M.; Novotny, K.; Cervenka, R. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Reale, L. [Faculty of Sciences, University of L' Aquila, Via Vetoio (Coppito 1), 67010 L' Aquila (Italy); Novotny, J.; Liska, M.; Samek, O. [Institute of Physical Engineering, Faculty of Mechanical Engineering, Brno University of Technology, Technicka 2896/2, 616 69 Brno (Czech Republic); Kanicky, V.; Hrdlicka, A. [Department of Chemistry, Faculty of Science, Masaryk University, Kotlarska 2, 611 37 Brno (Czech Republic); Stejskal, K.; Adam, V.; Kizek, R. [Department of Chemistry and Biochemistry, Faculty of Agronomy, Mendel University of Agriculture and Forestry, Zemedelska 1, 613 00 Brno (Czech Republic)

    2009-01-15

    Laser-Induced Breakdown Spectroscopy (LIBS) and Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS) were utilized for mapping the accumulation of Pb, Mg and Cu with a resolution up to 200 {mu}m in a up to cm x cm area of sunflower (Helianthus annuus L.) leaves. The results obtained by LIBS and LA-ICP-MS are compared with the outcomes from Atomic Absorption Spectrometry (AAS) and Thin-Layer Chromatography (TLC). It is shown that laser-ablation based analytical methods can substitute or supplement these techniques mainly in the cases when a fast multi-elemental mapping of a large sample area is needed.

  13. A proteomics study of the response of North Ronaldsay sheep to copper challenge

    Directory of Open Access Journals (Sweden)

    Haywood Susan

    2006-12-01

    Full Text Available Abstract Background The objective of this proteomics study was to identify proteins that changed expression as a result of copper challenge in the uniquely copper sensitive North Ronaldsay sheep and further, to compare those changes in expression with the more copper tolerant Cambridge breed. Such data gives us a proteome-centered perspective of the pathogenesis of copper-induced oxidative stress in this breed. Results Many proteins respond to copper challenge, but this study focuses on those exhibiting a differential response between the two breeds, related to liver copper content. As copper accumulated in the tissue, the pattern of expression of several proteins was markedly different, in North Ronaldsay sheep as compared to the Cambridge breed. Conclusion The pattern of changes was consistent with the greatly enhanced susceptibility of North Ronaldsay sheep to copper-induced oxidative stress, focused on mitochondrial disturbance with consequent activation of hepatic stellate cells. The expression profiles were sufficiently complex that the response could not simply be explained as a hypersensitivity to copper in North Ronaldsay sheep.

  14. Role of intron-mediated enhancement on accumulation of an Arabidopsis NB-LRR class R-protein that confers resistance to Cucumber mosaic virus.

    Directory of Open Access Journals (Sweden)

    Yukiyo Sato

    Full Text Available The accumulation of RCY1 protein, which is encoded by RESISTANCE TO CMV(Y (RCY1, a CC-NB-LRR class R-gene, is tightly correlated with the strength of the resistance to a yellow strain of Cucumber mosaic virus [CMV(Y] in Arabidopsis thaliana. In order to enhance resistance to CMV by overexpression of RCY1, A. thaliana was transformed with intron-less RCY1 cDNA construct under the control of strong CaMV35S promoter. Remarkably, a relative amount of RCY1 protein accumulation in the transformants was much lower than that in plants expressing genomic RCY1 under the control of its native promoter. To identify a regulatory element of RCY1 that could cause such differential levels of RCY1 accumulation, a series of RCY1 cDNA and genomic RCY1 constructs were transiently expressed in Nicotiana benthamiana leaves by the Agrobacterium-mediated infiltration method. Comparative analysis of the level of RCY1 accumulation in the leaf tissues transiently expressing each construct indicated that the intron located in the RCY1-coding region of genomic RCY1, but not the native RCY1 genomic promoter or the 5'-and 3'-untranslated regions of RCY1, was indispensable for high level RCY1 accumulation. The increased levels of RCY1 accelerated plant disease defense reactions. Interestingly, such intron-mediated enhancement of RCY1 accumulation depended neither on the abundance of the RCY1 transcript nor on the RCY1 specific-intron sequence. Taken together, intron-mediated RCY1 expression seems to play a key role in the expression of complete resistance to CMV(Y by maintaining RCY1 accumulation at high levels.

  15. Electro-biosorptive accumulation for use in enhanced detection of fluorogenic tracers and the removal of toxic entities from dilute solutions.

    Science.gov (United States)

    Nomikou, Nikolitsa; McHale, Anthony P

    2007-04-01

    An accumulating process based on electric field-assisted biosorption is described to facilitate the accumulation and enhanced detection of organic fluorogenic marker species in aqueous solution. Fluorescein was detected at concentrations as low as 0.6 microg l(-1). Using a mammalian cell-based bioassay, we demonstrate the use of the system to remove the toxic effects of species such as ethidium bromide and doxorubicin from complex solutions such as tissue culture medium. The use of such a system for the detection and removal of trace contaminants is discussed.

  16. Hair copper in intrauterine copper device users.

    Science.gov (United States)

    Thiery, M; Heyndrickx, A; Uyttersprot, C

    1984-03-01

    The antifertility effect of copper-bearing IUDs is based on continuous release of copper, which is a result of the reaction between the metal and the uterine secretions. Released cupric ions collect in the endometrium and in the uterine fluid but significant accumulation has not been found in the bloodstream or elsewhere. Following Laker's suggestion that hair be used for monitoring essential trace elements, e.g., copper, we checked the copper content of the hair of women wearing copper-bearing IUDs. Samples of untreated pubic hair removed by clipping before diagnostic curettage were obtained from 10 young (24-34 years old), white caucasian females who until then had been wearing an MLCu250 IUD for more than 1 year. Pubes from 10 comparable (sex, age, race) subjects who had never used a Cu-containing device served as controls. The unwashed material was submitted to the toxicology laboratory, where the copper content was assessed by flameless atomic absorption, a technique whose lower limit of measurement lies at a concentration of 0.05 mcg Cu/ml fluid (50 ppb). Hair samples were washed to remove extraneous traces of metal according to the prescriptions of the International Atomic Energy Agency, weighed, and mineralized, after which a small volume (10 mcl) of the diluted fluid was fed into the graphite furnace. Each sample (75-150 mg) was analyzed 4 times, both before and after washing. Since the cleaning procedure reduces the weight of the sample (mainly by the removal of fat, dust, etc.) this explains why the percentage copper content of washed hair is higher than that of unwashed hair belonging to the same subject. The results indicate that there was no significant difference (Mann-Whitney U test) between the mean copper levels of both unwashed and washed pubes from women who were using or had never used an MLCu250 IUD. We therefore conclude that the use of this copper-containing device is not associated with significant accumulation of copper in (pubic) hair.

  17. [b][/b]Impact of copper (Cu at the dose of 50 mg on haematological and biochemical blood parameters in turkeys, and level of Cu accumulation in the selected tissues as a source of information on product safety for consumers

    Directory of Open Access Journals (Sweden)

    Bogusław Makarski

    2014-09-01

    Full Text Available Introduction. The current state-of the art points to a positive impact of copper (Cu supplements on the general health status in poultry. Copper induces beneficial changes in the haematological and biochemical blood parameters. It also displays immunostimulating properties and helps maintain a proper microbiological balance in the digestive tract. [b]Objective[/b]. The objective of this study was to investigate the impact of Cu at the dose of 50 mg/kg BW, administered in organic and inorganic form, on the haematological and biochemical blood parameters and level of Cu bioaccumulation in the liver and pectoral muscle. [b]Materials and method[/b]. The study was carried out on 45 BUT-9 turkeys which had been were reared for 16 weeks. They were divided into 3 experimental groups: I – the control group; II – fed with CuSO[sub]4[/sub] at the dose of 50 mg Cu•dm [sup]-3 [/sup]H[sub]2[/sub]O; III – received a Cu chelate with lysine at the same dose. [b]Results[/b]. The administration of Cu at the dose exceeding the nutritional recommendations did not induce beneficial changes in the examined birds. This indicates that it is not necessary to administer Cu doses higher than the recommended levels. The extent of Cu accumulation in the pectoral muscle increased by 40% compared to the control group, whereas in the liver it was higher by 30–35% than in the birds without Cu administration. The level of Cu in tissues does not pose a risk to consumers. [b]Conclusions[/b]. The supplementation of Cu at the dose of 50 mg has a negative impact on the level of the analyzed parameters. The results of the presented study indicate that the administered Cu dose exceeds birds’ demand for this element.

  18. Zinc, copper, or cerium accumulation from metal oxide nanoparticles or ions in sweet potato: Yield effects and projected dietary intake from consumption.

    Science.gov (United States)

    Bradfield, Scott J; Kumar, Pawan; White, Jason C; Ebbs, Stephen D

    2017-01-01

    The potential release of metal oxide engineered nanoparticles (ENP) into agricultural systems has created the need to evaluate the impact of these materials on crop yield and food safety. The study here grew sweet potato (Ipomoea batatas) to maturity in field microcosms using substrate amended with three concentrations (100, 500 or 1000 mg kg DW(-1)) of either nZnO, nCuO, or nCeO2 or equivalent amounts of Zn(2+), Cu(2+), or Ce(4+). Adverse effects on tuber biomass were observed only for the highest concentration of Zn or Cu applied. Exposure to both forms of Ce had no adverse effect on yield and a slight positive benefit at higher concentrations on tuber diameter. The three metals accumulated in both the peel and flesh of the sweet potato tubers, with concentrations higher in the peel than the flesh for each element. For Zn, >70% of the metal was in the flesh and for Cu >50%. The peels retained 75-95% of Ce in the tubers. The projected dietary intake of each metal by seven age-mass classes from child to adult only exceeded the oral reference dose for chronic toxicity in a scenario where children consumed tubers grown at the highest metal concentration. The results throughout were generally not different between the ENP- and ionic-treatments, suggesting that the added ENPs underwent dissolution to release their component ions prior to accumulation. The results offer insight into the fate and impact of these ENPs in soils. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  19. Transgenic soya bean seeds accumulating β‐carotene exhibit the collateral enhancements of oleate and protein content traits

    National Research Council Canada - National Science Library

    Schmidt, Monica A; Parrott, Wayne A; Hildebrand, David F; Berg, R. Howard; Cooksey, Amanda; Pendarvis, Ken; He, Yonghua; McCarthy, Fiona; Herman, Eliot M

    2015-01-01

    Transgenic soya bean ( Glycine max ) plants overexpressing a seed‐specific bacterial phytoene synthase gene from Pantoea ananatis modified to target to plastids accumulated 845 μg β carotene g...

  20. Canine Models for Copper Homeostasis Disorders

    OpenAIRE

    Xiaoyan Wu; Leegwater, Peter A. J.; Hille Fieten

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper me...

  1. Canine Models for Copper Homeostasis Disorders

    OpenAIRE

    Xiaoyan Wu; Leegwater, Peter A.J.; Hille Fieten

    2016-01-01

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper me...

  2. Engineering Copper Carboxylate Functionalities on Water Stable Metal–Organic Frameworks for Enhancement of Ammonia Removal Capacities

    Energy Technology Data Exchange (ETDEWEB)

    Joshi, Jayraj N.; Garcia-Gutierrez, Erika Y.; Moran, Colton M.; Deneff, Jacob I.; Walton, Krista S.

    2017-02-02

    Functionalization of copper carboxylate groups on a series of UiO-66 metal organic framework (MOF) analogues and their corresponding impact on humid and dry ammonia adsorption behavior were studied. Relative locations of possible carboxylic acid binding sites for copper on the MOF analogues were varied on ligand and missing linker defect sites. Materials after copper incorporation exhibited increased water vapor and ammonia affinity during isothermal adsorption and breakthrough experiments, respectively. The introduction of copper markedly increased ammonia adsorption capacities for all adsorbents possessing carboxyl binding sites. In particular, the new MOF UiO-66-(COOCu)2 displayed the highest ammonia breakthrough capacities of 6.38 and 6.84 mmol g–1 under dry and humid conditions, respectively, while retaining crystallinity and porosity. Relative carboxylic acid site locations were also found to impact sorbent stability, as missing linker defect functionalized materials degraded under humid conditions after copper incorporation. Postsynthetic metal insertion provides a method for adding sites that are analogous to open metal sites while maintaining good structural stability.

  3. Same-single-cell analysis using the microfluidic biochip to reveal drug accumulation enhancement by an amphiphilic diblock copolymer drug formulation.

    Science.gov (United States)

    Khamenehfar, Avid; Wan, Chung Ping Leon; Li, Paul C H; Letchford, Kevin; Burt, Helen M

    2014-11-01

    Multidrug resistance (MDR) is one of the major obstacles in drug delivery, and it is usually responsible for unsuccessful cancer treatment. MDR may be overcome by using MDR inhibitors. Among different classes of these inhibitors that block drug efflux mediated by permeability-glycoprotein (P-gp), less toxic amphiphilic diblock copolymers composed of methoxypolyethyleneglycol-block-polycaprolactone (MePEG-b-PCL) have been studied extensively. The purpose of this work is to evaluate how these copolymer molecules can reduce the efflux, thereby enhancing the accumulation of P-gp substrates (e.g., daunorubicin or DNR) in MDR cells. Using conventional methods, it was found that the low-molecular-weight diblock copolymer, MePEG17-b-PCL5 (PCL5), enhanced drug accumulation in MDCKII-MDR1 cells, but the high-molecular-weight version, MePEG114-b-PCL200 (PCL200), did not. However, when PCL200 was mixed with PCL5 (and DNR) in order to encapsulate them to facilitate drug delivery, there was no drug enhancement effect attributable to PCL5, and the reason for this negative result was unclear. Since drug accumulation measured on different cell batches originated from single cells, we employed the same-single-cell analysis in the accumulation mode (SASCA-A) to find out the reason. A microfluidic biochip was used to select single MDR cells, and the accumulation of DNR was fluorescently measured in real time on these cells in the absence and presence of PCL5. The SASCA-A method allowed us to obtain drug accumulation information faster in comparison to conventional assays. The SASCA-A results, and subsequent curve-fitting analysis of the data, have confirmed that when PCL5 was encapsulated in PCL200 nanoparticles as soon as they were synthesized, the ability of PCL5 to enhance DNR accumulation was retained, thus suggesting PCL200 as a promising delivery system for encapsulating P-gp inhibitors, such as PCL5.

  4. Copper-64-diacetyl-bis (N{sup 4}-methylthiosemicarbazone) accumulates in rich regions of CD133{sup +} highly tumorigenic cells in mouse colon carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Yoshii, Yukie [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Furukawa, Takako [Molecular Imaging Center, National Institute of Radiological Sciences, Inage, Chiba 263-8555 (Japan); Kiyono, Yasushi [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Watanabe, Ryo [Faculty of Engineering, University of Fukui, Eiheiji, Fukui 910-8507 (Japan); Waki, Atsuo [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Mori, Tetsuya [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Yoshii, Hiroshi; Oh, Myungmi [Faculty of Medical Sciences, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Asai, Tatsuya [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Faculty of Engineering, University of Fukui, Eiheiji, Fukui 910-8507 (Japan); Okazawa, Hidehiko [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Welch, Michael J. [Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, Missouri 63110 (United States); Fujibayashi, Yasuhisa [Biomedical Imaging Research Center, University of Fukui, Eiheiji, Fukui 910-1193 (Japan); Molecular Imaging Center, National Institute of Radiological Sciences, Inage, Chiba 263-8555 (Japan)], E-mail: yfuji@u-fukui.ac.jp

    2010-05-15

    Introduction: {sup 64}Cu-diacetyl-bis (N{sup 4}-methylthiosemicarbazone) ({sup 64}Cu-ATSM) is a potential imaging agent of hypoxic tumor for use with PET. Recent literature demonstrated that cancer cells expressing CD133, which is a frequently used marker for so-called cancer stem cells or cancer stem cell-like cells (collectively referred to here as CSCs), contribute to tumor's therapeutic resistance and metastasis ability. Culturing under hypoxia is also reported to enlarge the proportion of CD133{sup +} cells, which would indicate survival advantage of CD133{sup +} cells under hypoxia. Here, we investigated the relationships between {sup 64}Cu-ATSM accumulation and existence of CD133{sup +} cells using mouse colon carcinoma (colon-26) tumor. Methods: Intratumor distribution of {sup 64}Cu-ATSM and {sup 18}F-fluorodeoxyglucose ({sup 18}FDG) was compared with immunohistochemical staining for CD133 with a colon-26 model. In vitro characterization of CD133{sup +} colon-26 cells was also performed. Results: In colon-26 tumors, {sup 64}Cu-ATSM localized preferentially in regions with a high density of CD133{sup +} cells. The percentage of CD133{sup +} cells was 11-fold higher in {sup 64}Cu-ATSM high-uptake regions compared with {sup 18}FDG high- (but {sup 64}Cu-ATSM low-) uptake regions. CD133{sup +} colon-26 cells showed characteristics previously linked with CSCs in other cancer cell lines, such as high colony-forming ability, high tumor-initiating ability and enrichment under hypoxic cultivation. The proportion of CD133{sup +} cells was enlarged by culturing under glucose starvation as well as hypoxia, and {sup 64}Cu-ATSM uptake was increased under such conditions. Conclusions: Our findings showed that, in colon-26 tumors, {sup 64}Cu-ATSM accumulates in rich regions of CD133{sup +} cells with characteristics of CSCs. Therefore {sup 64}Cu-ATSM could be a potential imaging agent for rich regions of CD133{sup +} cells, associated with CSCs, within tumors.

  5. Using copper substrate to enhance electron field emission properties of carbon nanotube/diamond double-layered structure

    Science.gov (United States)

    Yang, Lezhi; Sujith Kumar, C. S.; Li, Yuan-shi; Niakan, Hamid; Zhang, Chunzi; Hirose, Akira; Aravind, Suresh; Yang, Qiaoqin

    2015-01-01

    Vertically aligned carbon nanotube (CNT)/diamond double-layered structure was synthesized on copper (Cu) substrate by hot-filament chemical vapor deposition. The structure was characterized by scanning electron microscopy, transmission electron microscopy, and Raman spectroscopy. The results show that the diamond layer has good adhesion to the Cu substrate and the CNTs have direct contact with the diamond layer. Field electron emission measurement shows that the double-layered structure on copper has very good emission stability and a much lower turn-on field than that on silicon (Si).

  6. Enhanced accumulation of phytosterols and phenolic compounds in cyclodextrin-elicited cell suspension culture of Daucus carota.

    Science.gov (United States)

    Miras-Moreno, Begoña; Almagro, Lorena; Pedreño, M A; Sabater-Jara, Ana Belén

    2016-09-01

    In this work, suspension-cultured cells of Daucus carota were used to evaluate the effect of β-cyclodextrins on the production of isoprenoid and phenolic compounds. The results showed that the phytosterols and phenolic compounds were accumulated in the extracellular medium (15100μgL(-1) and 477.46μgL(-1), respectively) in the presence of cyclodextrins. Unlike the phytosterol and phenolic compound content, β-carotene (1138.03μgL(-1)), lutein (25949.54μgL(-1)) and α-tocopherol (8063.82μgL(-1)) chlorophyll a (1625.13μgL(-1)) and b (9.958 (9958.33μgL(-1)) were mainly accumulated inside the cells. Therefore, cyclodextrins were able to induce the cytosolic mevalonate pathway, increasing the biosynthesis of phytosterols and phenolic compounds, and accumulate them outside the cells. However, in the absence of these cyclic oligosaccharidic elicitors, carrot cells mainly accumulated carotenoids through the methylerythritol 4-phosphate pathway. Therefore, the use of cyclodextrins would allow the extracellular accumulation of both phytosterols and phenolic compounds by diverting the carbon flux towards the cytosolic mevalonate/phenylpropanoid pathway.

  7. Flow boiling heat transfer enhancement on copper surface using Fe doped Al{sub 2}O{sub 3}–TiO{sub 2} composite coatings

    Energy Technology Data Exchange (ETDEWEB)

    Sujith Kumar, C.S., E-mail: sujithdeepam@gmail.com [Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India); Suresh, S., E-mail: ssuresh@nitt.edu [Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India); Aneesh, C.R., E-mail: aneeshcr87@gmail.com [Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India); Santhosh Kumar, M.C., E-mail: santhoshmc@nitt.edu [Department of Physics, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India); Praveen, A.S., E-mail: praveen_as_1215@yahoo.co.in [Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015, Tamil Nadu (India); Raji, K., E-mail: raji.kochandra@gmail.com [School of Nano Science and Technology, National Institute of Technology, Calicut 673601, Kerala (India)

    2015-04-15

    Graphical abstract: - Highlights: • Fe–Al{sub 2}O{sub 3}–TiO{sub 2} composite coatings were coated on the copper using spray pyrolysis. • Effect of Fe doping on porosity was determined using AFM. • Effect of Fe doping on hydrophilicity was determined. • Higher enhancement in CHF was obtained for 7.2 at% Fe doped coated sample. - Abstract: In the present work, flow boiling experiments were conducted to study the effect of spray pyrolyzed Fe doped Al{sub 2}O{sub 3}–TiO{sub 2} composite coatings over the copper heater blocks on critical heat flux (CHF) and boiling heat transfer coefficient. Heat transfer studies were conducted in a mini-channel of overall dimension 30 mm × 20 mm × 0.4 mm using de-mineralized water as the working fluid. Each coated sample was tested for two mass fluxes to explore the heat transfer performance. The effect of Fe addition on wettability and porosity of the coated surfaces were measured using the static contact angle metre and the atomic force microscope (AFM), and their effect on flow boiling heat transfer were investigated. A significant enhancement in CHF and boiling heat transfer coefficient were observed on all coated samples compared to sand blasted copper surface. A maximum enhancement of 52.39% and 44.11% in the CHF and heat transfer coefficient were observed for 7.2% Fe doped TiO{sub 2}–Al{sub 2}O{sub 3} for a mass flux of 88 kg/m{sup 2} s.

  8. Study on the correlation between copper oxide nanoparticles induced growth suppression and enhanced lignification in Indian mustard (Brassica juncea L.).

    Science.gov (United States)

    Nair, Prakash M Gopalakrishnan; Chung, Ill Min

    2015-03-01

    In this study, the morphological, physiological and molecular level effects of copper oxide nanoparticles (CuONPs) were studied in an economically important oil seed crop Brassica juncea L. The possible involvement of lignification on shoot-root growth retardation was also studied. The seedlings were exposed to 0, 20, 50, 100, 200, 400 and 500mg/L of CuONPs in semi-solid half strength Murashige and Skoog medium under controlled growth chamber conditions for 14 days. Exposure to CuONPs resulted in suppression of shoot-growth, reduction in total chlorophyll and carotenoids contents as well modification of root system architecture such as shortening of primary and lateral roots. Significant increases in hydrogen peroxide formation, peroxidase enzyme activity and lignification of shoots and roots were observed. The lipid peroxidation levels increased significantly in shoots and roots of B. juncea seedlings. Phloroglucinol-HCl staining revealed enhanced lignification of shoot and roots. Gene expression studies revealed significant activation of CuZn superoxide dismutase (CuZnSOD) in roots at all concentrations of CuONPs exposure. In shoots significant up-regulation of CuZnSOD gene was observed upon exposure to 100, 200 and 400 mg/L of CuONPs exposure. However no change in the expression levels of MnSOD gene was observed in both stem and roots. The expression of catalase (CAT) and ascorbate peroxidase (APX) genes were also not changed in shoots. However, significant inhibition of CAT and APX genes were observed in roots of B. juncea plants under exposure to 100, 200, 400 and 500 mg/L of CuONPs exposure. The SOD enzyme activity significantly increased in roots under exposure to 50-500 mg/L of CuONPs and in shoots as a result of exposure to 100-500 mg/L of CuONPs. The APX activity significantly decreased in roots upon exposure to 50-500 mg/L of CuONPs. In shoots, the APX activity significantly decreased upon exposure to 200-500 mg/L of CuONPs.

  9. Bioindication of air pollution effects near a copper smelter in Brazil using mango trees and soil microbiological properties

    Energy Technology Data Exchange (ETDEWEB)

    Klumpp, Andreas; Hintemann, Therese; Santana Lima, Josanidia; Kandeler, Ellen

    2003-12-01

    A field study near the copper smelter of a large industrial complex examined air pollution effects on vegetation and soil parameters in Camacari (northeast Brazil). Close to the smelter, soil pH-value was lower and total acidity as well as organic carbon contents were higher compared with a site far from the source and two reference sites. The acidification of top soil particularly and the drastically enhanced plant-available copper concentrations were caused by atmospheric deposition. High sulphur and copper deposition significantly reduced microbial biomass and altered functional diversity of soil microorganisms (arylsulphatase and xylanase). Large accumulations of sulphur, arsenic and copper were detected in mango leaves (Mangifera indica) growing downwind from the smelter suggesting potential food chain-mediated risk. - Atmospheric emissions in northeast Brazil have transformed soil pH, accumulated in soil and plants as sulphur and heavy metals, and affected the functional diversity of soil microorganisms.

  10. Plasmonic enhancement of CO{sub 2} conversion to methane using sculptured copper thin films grown directly on TiO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Hyeonseok [Department of Electrical Engineering, PA State University, University Park 16802 (United States); In, Suil, E-mail: insuil@dgist.ac.kr [Department of Energy Systems Engineering, DGIST 50-1 Sang-Ri, Hyeongpung-Myeon, Dalseong-Gun, Deagu, 711-873 (Korea, Republic of); Horn, Mark W., E-mail: MHorn@engr.psu.edu [Department of Engineering Science and Mechanics, PA State University, University Park 16802-6812 (United States)

    2014-08-28

    Columnar Cu nanostructures with tunable lengths are formed directly on porous TiO{sub 2} by oblique-angle electron beam evaporation and used as a cocatalyst for photocatalytic conversion of CO{sub 2} to methane. A remarkable enhancement in methane production rate is measured using the sculptured copper films with a maximum of 124.3 ppm · cm{sup −2} · h{sup −1} for 160 nm long Cu columnar structures under AM 1.5 illumination. This high methane production rate is attributed to a plasmonic enhancement effect due to the columnar Cu nanostructures. - Highlights: • Cu sculptured thin films (STFs) directly grown on TiO{sub 2} catalytic films • Excellent performance in methane production rate by TiO{sub 2}/Cu STFs films • Enhancement in methane production by plasmonic effect of Cu STFs.

  11. Inhibition of human high-affinity copper importer Ctr1 orthologous in the nervous system of Drosophila ameliorates Aβ42-induced Alzheimer's disease-like symptoms.

    Science.gov (United States)

    Lang, Minglin; Fan, Qiangwang; Wang, Lei; Zheng, Yajun; Xiao, Guiran; Wang, Xiaoxi; Wang, Wei; Zhong, Yi; Zhou, Bing

    2013-11-01

    Disruption of copper homeostasis has been implicated in Alzheimer's disease (AD) during the last 2 decades; however, whether copper is a friend or a foe is controversial. Within a genetically tractable Drosophila AD model, we manipulated the expression of human high-affinity copper importer orthologous in Drosophila to explore the in vivo roles of copper ions in the development of AD. We found that inhibition of Ctr1C expression by RNAi in Aβ-expressing flies significantly reduced copper accumulation in the brains of the flies as well as ameliorating neurodegeneration, enhancing climbing ability, and prolonging lifespan. Interestingly, Ctr1C inhibition led to a significant increase in higher-molecular-weight Aβ42 forms in brain lysates, whereas it was accompanied by a trend of decreased expression of amyloid-β degradation proteases (including NEP1-3 and IDE) with age and reduced Cu-Aβ interaction-induced oxidative stress in Ctr1C RNAi flies. Similar results were obtained from inhibiting another copper importer Ctr1B and overexpressing a copper exporter DmATP7 in the nervous system of AD flies. These results imply that copper may play a causative role in developing AD, as either Aβ oligomers or aggregates were less toxic in a reduced copper environment or one with less copper binding. Early manipulation of brain copper uptake can have a great effect on Aβ pathology.

  12. The discrepancy between the absence of copper deposition and the presence of neuronal damage in the brain of Atp7b(-/-) mice.

    Science.gov (United States)

    Dong, Yi; Shi, Sheng-Sheng; Chen, Sheng; Ni, Wang; Zhu, Min; Wu, Zhi-Ying

    2015-02-01

    Wilson's disease (WD) is caused by mutations within the copper-transporting ATPase (ATP7B), characterized by copper deposition in various organs, principally the liver and the brain. With the availability of Atp7b(-/-) mice, the valid animal model of WD, the mechanism underlying copper-induced hepatocyte necrosis has been well understood. Nonetheless, little is known about the adverse impact of copper accumulation on the brain in WD. Therefore, the aim of this study was to identify copper disturbances according to various brain compartments and further dissect the causal relationship between copper storage and neuronal damage using Atp7b(-/-) mice. Copper levels in the liver, whole brain, brain compartments and basal ganglia mitochondria of Atp7b(-/-) mice and age-matched controls were measured by atomic absorption spectroscopy. Delicate electron microscopic studies on hepatocytes and neurons in the basal ganglia were performed. Here we further confirmed the remarkably elevated copper content and abnormal ultrastructure findings in livers of Atp7b(-/-) mice. Interestingly, we found the ultrastructure abnormalities in neurons of the basal ganglia of Atp7b(-/-) mice, whereas copper deposition was not detected in the whole brain, even within the basal ganglia and its mitochondria. The disparity provided a new understanding of neuronal dysfunction in WD, and strongly indicated that copper might not be the sole causative player and other unidentified pathogenic factors could enhance the toxic effects of copper on neurons in WD.

  13. Enhancing effect of lipids and emulsifiers on the accumulation of quercetin metabolites in blood plasma after the short-term ingestion of onion by rats.

    Science.gov (United States)

    Azuma, Keiko; Ippoushi, Katsunari; Ito, Hidekazu; Horie, Hideki; Terao, Junji

    2003-12-01

    The effects of co-ingested lipids and emulsifiers on the accumulation of quercetin metabolites in blood plasma after the short-term ingestion of onion by rats were investigated. Plasma extracts of rats that had been fed onion-containing diets for one and two weeks were analyzed by HPLC with electrochemical detection after a treatment with sulfatase/beta-glucuronidase. Almost all of the quercetin metabolites in the plasma were sulfate/glucuronide conjugates of quercetin and isorhamnetin. More than 4.6% (w/w) of soybean oil in the diets significantly enhanced the accumulation of quercetin metabolites in the plasma. Fish oil and beef tallow increased this to an extent similar to that with soybean oil, and lecithin was more effective than the other three lipids. Two emulsifiers, sodium caseinate and sucrose fatty acid ester, also showed an enhancing effect on the accumulation of quercetin metabolites. These results indicate that co-ingested lipids and emulsifiers could enhance the bioavailability of quercetin glucosides in onion.

  14. Artesunate has its enhancement on antibacterial activity of β-lactams via increasing the antibiotic accumulation within methicillin-resistant Staphylococcus aureus (MRSA).

    Science.gov (United States)

    Jiang, Weiwei; Li, Bin; Zheng, Xinchuan; Liu, Xin; Pan, Xichun; Qing, Rongxin; Cen, Yanyan; Zheng, Jiang; Zhou, Hong

    2013-06-01

    Methicillin-resistant Staphylococcus aureus (MRSA) has now emerged as a predominant and serious pathogen because of its resistance to a large group of antibiotics, leading to high morbidity and mortality. Therefore, to develop new agents against resistance is urgently required. Previously, artesunate (AS) was found to enhance the antibacterial effect of β-lactams against MRSA. In this study, AS was first found to increase the accumulation of antibiotics (daunorubicin and oxacillin) within MRSA by laser confocal microscopy and liquid chromatography-tandem MS method, suggesting the increased antibiotics accumulation might be related to the enhancement of AS on antibiotics. Furthermore, AS was found not to destroy the cell structure of MRSA by transmission electron microscope. AS was found to inhibit gene expressions of important efflux pumps such as NorA, NorB and NorC, but not MepA, SepA and MdeA. In conclusion, our results showed that AS was capable of enhancing the antibacterial activity of β-lactams via increasing antibiotic accumulations within MRSA through inhibiting gene expressions of efflux pumps such as NorA, NorB and NorC, but did not destroy the cell structure of MRSA. AS could be further investigated as a candidate drug for treatment of MRSA infection.

  15. Co-expression of Arabidopsis thaliana phytochelatin synthase and Treponema denticola cysteine desulfhydrase for enhanced arsenic accumulation.

    Science.gov (United States)

    Tsai, Shen-Long; Singh, Shailendra; Dasilva, Nancy A; Chen, Wilfred

    2012-02-01

    Arsenic is one of the most hazardous pollutants found in aqueous environments and has been shown to be a carcinogen. Phytochelatins (PCs), which are cysteine-rich and thio-reactive peptides, have high binding affinities for various metals including arsenic. Previously, we demonstrated that genetically engineered Saccharomyces cerevisiae strains expressing phytochelatin synthase (AtPCS) produced PCs and accumulated arsenic. In an effort to further improve the overall accumulation of arsenic, cysteine desulfhydrase, an aminotransferase that converts cysteine into hydrogen sulfide under aerobic condition, was co-expressed in order to promote the formation of larger AsS complexes. Yeast cells producing both AtPCS and cysteine desulfhydrase showed a higher level of arsenic accumulation than a simple cumulative effect of expressing both enzymes, confirming the coordinated action of hydrogen sulfide and PCs in the overall bioaccumulation of arsenic.

  16. Copper hypersensitivity.

    Science.gov (United States)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-10-01

    The world production of copper is steadily increasing. Although humans are widely exposed to copper-containing items on the skin and mucosa, allergic reactions to copper are only infrequently reported. To review the chemistry, biology and accessible data to clarify the implications of copper hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common. As a metal, it possesses many of the same qualities as nickel, which is a known strong sensitizer. Cumulative data on subjects with presumed related symptoms and/or suspected exposure showed that a weighted average of 3.8% had a positive patch test reaction to copper. We conclude that copper is a very weak sensitizer as compared with other metal compounds. However, in a few and selected cases, copper can result in clinically relevant allergic reactions.

  17. Copper inducing Aβ42 rather than Aβ40 nanoscale oligomer formation is the key process for Aβ neurotoxicity

    Science.gov (United States)

    Jin, Lu; Wu, Wei-Hui; Li, Qiu-Ye; Zhao, Yu-Fen; Li, Yan-Mei

    2011-11-01

    Copper is known to be a critical factor in Alzheimer's disease (AD) pathogenesis, as it is involved in amyloid-β (Aβ) peptide related toxicity. However, the relationship between neurotoxicity and Aβ peptide in the presence of copper remains unclear. The effect of copper has not been clearly differentiated between Aβ42 and Aβ40, and it is still debated whether copper-mediated neurotoxicity is due to reactive oxygen species (ROS) accumulation or other molecular mechanisms. Here, we describe that copper dramatically affects Aβ42 aggregation and enhances Aβ42 cytotoxicity while it shows no significant effects on Aβ40. These phenomena are mainly because that the strong interactions between copper and Aβ42 lead to great conformation changes, and stabilize Aβ42 aggregates at highly toxic nanoscale oligomer stage, whereas copper shows no similar impact on Aβ40. We also propose a possible molecular mechanism that copper enhances Aβ42 cytotoxicity via perturbing membrane structure. Moreover, we test the effect of an analogue of copper, nickel, on Aβ aggregation and cytotoxicity, finding that nickel also enhances cytotoxicity via Aβ42 nanoscale oligomer formation. These results clarify that the copper-induced Aβ42 nanoscale oligomer formation is the key process for Aβ neurotoxicity, and suggest that disrupting the interactions between copper and Aβ42 peptide to inhibit nanoscale oligomerization process, deserves more attention in AD drug development.Copper is known to be a critical factor in Alzheimer's disease (AD) pathogenesis, as it is involved in amyloid-β (Aβ) peptide related toxicity. However, the relationship between neurotoxicity and Aβ peptide in the presence of copper remains unclear. The effect of copper has not been clearly differentiated between Aβ42 and Aβ40, and it is still debated whether copper-mediated neurotoxicity is due to reactive oxygen species (ROS) accumulation or other molecular mechanisms. Here, we describe that copper

  18. Enhancement and Prediction of Adhesion Strength of Copper Cold Spray Coatings on Steel Substrates for Nuclear Fuel Repository

    Science.gov (United States)

    Fernández, R.; MacDonald, D.; Nastić, A.; Jodoin, B.; Tieu, A.; Vijay, M.

    2016-12-01

    Thick copper coatings have been envisioned as corrosion protection barriers for steel containers used in repositories for nuclear waste fuel bundles. Due to its high deposition rate and low oxidation levels, cold spray is considered as an option to produce these coatings as an alternative to traditional machining processes to create corrosion protective sleeves. Previous investigations on the deposition of thick cold spray copper coatings using only nitrogen as process gas on carbon steel substrates have continuously resulted in coating delamination. The current work demonstrates the possibility of using an innovative surface preparation process, forced pulsed waterjet, to induce a complex substrate surface morphology that serves as anchoring points for the copper particles to mechanically adhere to the substrate. The results of this work show that, through the use of this surface preparation method, adhesion strength can be drastically increased, and thick copper coatings can be deposited using nitrogen. Through finite element analysis, it was shown that it is likely that the bonding created is purely mechanical, explaining the lack of adhesion when conventional substrate preparation methods are used and why helium is usually required as process gas.

  19. An integrated method incorporating sulfur-oxidizing bacteria and electrokinetics to enhance removal of copper from contaminated soil

    Energy Technology Data Exchange (ETDEWEB)

    Maini, G.; Sharman, A.K.; Sunderland, G.; Knowles, C.J.; Jackman, S.A.

    2000-03-15

    The combination of bioleaching and electrokinetics for the remediation of metal contaminated land has been investigated. In bioleaching, bacteria convert reduced sulfur compounds to sulfuric acid, acidifying soil and mobilizing metal ions. In electrokinetics, DC current acidifies soil, and mobilized metals are transported to the cathode by electromigration. When bioleaching was applied to silt soil artificially contaminated with seven metals and amended with sulfur, bacterial activity was partially inhibited and limited acidification occurred. Electrokinetic treatment of silt soil contaminated solely with 1000 mg/kg copper nitrate showed 89% removal of copper from the soil within 15 days. To combine bioleaching and electrokinetics sequentially, preliminary partial acidification was performed by amending copper-contaminated soil with sulfur (to 5% w/w) and incubating at constant moisture (30% w/w) and temperature (20 C) for 90 days. Indigenous sulfur oxidizing bacteria partially acidified the soil from pH 8.1 to 5.4. This soil was then treated by electrokinetics yielding 86% copper removal in 16 days. In the combined process, electrokinetics stimulated sulfur oxidation, by removing inhibitory factors, yielding a 5.1-fold increase in soil sulfate concentration. Preacidification by sulfur-oxidizing bacteria increased the cost-effectiveness of the electrokinetic treatment by reducing the power requirement by 66%.

  20. [Mercury and copper accumulation during last fifty years and their potential ecological risk assessment in sediment of mangrove wetland of Shenzhen, China].

    Science.gov (United States)

    Li, Rui-Li; Chai, Min-Wei; Qiu, Guo-Yu; He, Bei

    2012-12-01

    The processes of sediment transport and deposition can record some relative anthropogenic information in gulf region. Chronological analysis of the sediment core collected from mangrove wetland in Shenzhen Bay showed that the sedimentation rate was about 1.38 cm x a(-1). Soil buck density, pH, electrical conductivity (EC) and total organic carbon (TOC) changed in range of 0.36-0.71 g x cm(-3), 6-7, 2.93 x 10(3) -4.97 x 10(3) microS x cm(-1), and 1.5% - 3.8%, respectively. With the increase of soil depth, the soil buck density and EC increased gradually. However, the TOC decreased, with no significant change of pH. Contents of Hg and Cu in the whole depth of core ranged between 92-196 ng x g(-1) and 29-83 microg x g(-1), respectively. And both of them in sediment increased firstly and then decreased with the increasing soil depth. At 14 cm depth, contents of Hg and Cu reached up to the highest levels. Correspondingly, the ecological risk of Hg and Cu changed similarly with the contents of Hg and Cu. At 14 cm depth, the ecological risk indexes of Hg and Cu were at the highest levels of 39.10 and 13.85, respectively. The potential ecological risks of both Hg and Cu in sediments were mild. The rapid economical development of Hong Kong in 1960-1985 and Shenzhen in 1985-2000 contributed much to the Hg and Cu accumulation in mangrove wetland of Shenzhen Bay, China. Since the year of 2000, the reduction in contents of Hg and Cu has been expected as a consequence of the adoption of contamination control policies, improving the environment for growth of mangrove. In conclusion, the variations of core sediment heavy metal contents and its ecological risk assessment along the vertical profile reveal the interaction processes and extent of anthropogenic influences from the areas around the Shenzhen Bay and the catchments.

  1. Uptake of copper ion by activated sludge and its bacterial community variation analyzed by 16S rDNA

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    The effect and uptake of copper ion on SBR(sequence batch reactor) biological treatment system was studied in this paper. Special nutrient and powder activated carbon(PAC) additive were tested as uptake stimulation technique. Results showed that copper ion had higher effect on unacclimated activated sludge system than on acclimated one. The special nutrient adding could enhance the uptake of copper significantly, while PAC adding could improve the sludge settling and decrease the turbidity of effluent. The variation of bacterial community analyzed by 16S rDNA method showed the acclimation of copper could increase copper resistance species, and excess accumulation could cause some species diminish. It was confirmed that acclimation could improve the resistance and uptake ability of microorganism to heavy metal.

  2. Effects of copper on chlorophyll, proline, protein and abscisic acid level of sunflower (Helianthus annuus L.) seedlings.

    Science.gov (United States)

    Zengin, Fikriye Kirbag; Kirbag, Sevda

    2007-07-01

    The effect of copperchloride (CuCl2) on the level of chlorophyll (a+b), proline, protein and abscisic acid in sunflower (Helianthus annuus L.) seedlings were investigated Control and copper treated (0.4, 0.5 and 0.6 mM) seedlings were grown for ten days in Hoagland solution. Abscisic acid content was determined in root, shoot and leaf tissues of seedlings by HPLC. Copper stress caused significant increase of the abscisic acid contents in roots, shoots and leaves of seedlings. The increase was dependent on the copper salt concentration. Enhanced accumulation of proline in the leaves of seedlings exposed to copper was determined, as well as a decrease of chlorophyll (a+b) and total protein (p Helianthus annuus L.) seedlings. Thus, we assumed that copper levels increase above some critical points seedling growth get negative effects. This assumption is in line with previous findings.

  3. Enhanced tumor necrosis factor suppression and cyclic adenosine monophosphate accumulation by combination of phosphodiesterase inhibitors and prostanoids

    NARCIS (Netherlands)

    Sinha, B; Semmler, J; Eisenhut, T; Eigler, A; Endres, S

    1995-01-01

    We investigated cooperative effects of phosphodiesterase (PDE) inhibitors and prostanoids on cyclic adenosine monophosphate (cAMP) accumulation and tumor necrosis factor (TNF)-alpha synthesis in human peripheral blood mononuclear cells (PBMC). PDE inhibitors alone induced only a small increase in cA

  4. Assessment and application of a snowblow modelling approach for identifying enhanced snow accumulation in areas of former glaciation

    Science.gov (United States)

    Mills, Stephanie; Smith, Michael; Le Brocq, Anne; Ardakova, Ekaterina; Hillier, John; Boston, Clare

    2016-04-01

    The redistribution of snow by wind can play an important role in providing additional mass to the surface of glaciers and can, therefore, have an impact on the glacier's surface mass balance. In areas of marginal glaciation, this local topo-climatic effect may be prove crucial for the initiation and survival of glaciers, whilst it can also increase heterogeneity in the distribution of snow on ice caps and ice sheets. We present a newly developed snowblow model which calculates spatial variations in relative snow accumulation that result from variations in topography. We apply this model to areas of former marginal glaciation in the Brecon Beacons, Wales and an area of former plateau icefield glaciation in the Monadhliath, Scotland. We can then determine whether redistribution by snow can help explain variations in the estimated equilibrium line altitudes (ELAs) of these former glaciers. Specifically, we compare the areas where snow is modelled as accumulating, to the reconstructed glacier surface, which is based on mapped moraines believed to be of Younger Dryas age. The model is applied to 30 m resolution DEMs and potential snow accumulation is simulated from different wind directions in order to determine the most likely contributing sector. Total snow accumulation in sub-set areas is then calculated and compared to the reconstructed glacier area. The results suggest that areas with larger amounts of snow accumulation often correspond with those where the ELA is lower than surrounding glaciers and vice versa, in both the marginal and icefield setting, suggesting that the role of snowblow in supplying additional mass to the surface of glaciers is significant.

  5. Copper transport.

    Science.gov (United States)

    Linder, M C; Wooten, L; Cerveza, P; Cotton, S; Shulze, R; Lomeli, N

    1998-05-01

    In adult humans, the net absorption of dietary copper is approximately 1 mg/d. Dietary copper joins some 4-5 mg of endogenous copper flowing into the gastrointestinal tract through various digestive juices. Most of this copper returns to the circulation and to the tissues (including liver) that formed them. Much lower amounts of copper flow into and out of other major parts of the body (including heart, skeletal muscle, and brain). Newly absorbed copper is transported to body tissues in two phases, borne primarily by plasma protein carriers (albumin, transcuprein, and ceruloplasmin). In the first phase, copper goes from the intestine to the liver and kidney; in the second phase, copper usually goes from the liver (and perhaps also the kidney) to other organs. Ceruloplasmin plays a role in this second phase. Alternatively, liver copper can also exit via the bile, and in a form that is less easily reabsorbed. Copper is also present in and transported by other body fluids, including those bathing the brain and central nervous system and surrounding the fetus in the amniotic sac. Ceruloplasmin is present in these fluids and may also be involved in copper transport there. The concentrations of copper and ceruloplasmin in milk vary with lactational stage. Parallel changes occur in ceruloplasmin messenger RNA expression in the mammary gland (as determined in pigs). Copper in milk ceruloplasmin appears to be particularly available for absorption, at least in rats.

  6. The effects of copper proximity on oxalate production in Fibroporia radiculosa

    Science.gov (United States)

    Katie M. Jenkins; Carol A. Clausen; Frederick Green III

    2014-01-01

    Copper remains a key component used in wood preservatives available today. However, the observed tolerance of several critical wood rotting organisms continues to be problematic. Tolerance to copper has been linked to the production and accumulation of oxalate, which precipitates copper into insoluble copper-oxalate crystals, thus inactivating copper ions. The purpose...

  7. Restoring Mitochondrial Function: A Small Molecule-mediated Approach to Enhance Glucose Stimulated Insulin Secretion in Cholesterol Accumulated Pancreatic beta cells

    Science.gov (United States)

    Asalla, Suman; Girada, Shravan Babu; Kuna, Ramya S.; Chowdhury, Debabrata; Kandagatla, Bhaskar; Oruganti, Srinivas; Bhadra, Utpal; Bhadra, Manika Pal; Kalivendi, Shasi Vardhan; Rao, Swetha Pavani; Row, Anupama; Ibrahim, A.; Ghosh, Partha Pratim; Mitra, Prasenjit

    2016-06-01

    Dyslipidemia, particularly the elevated serum cholesterol levels, aggravate the pathophysiology of type 2 diabetes. In the present study we explored the relationship between fasting blood sugar and serum lipid parameters in human volunteers which revealed a significant linear effect of serum cholesterol on fasting blood glucose. Short term feeding of cholesterol enriched diet to rodent model resulted in elevated serum cholesterol levels, cholesterol accumulation in pancreatic islets and hyperinsulinemia with modest increase in plasma glucose level. To explore the mechanism, we treated cultured BRIN-BD11 pancreatic beta cells with soluble cholesterol. Our data shows that cholesterol treatment of cultured pancreatic beta cells enhances total cellular cholesterol. While one hour cholesterol exposure enhances insulin exocytosis, overnight cholesterol accumulation in cultured pancreatic beta cells affects cellular respiration, and inhibits Glucose stimulated insulin secretion. We further report that (E)-4-Chloro-2-(1-(2-(2,4,6-trichlorophenyl) hydrazono) ethyl) phenol (small molecule M1) prevents the cholesterol mediated blunting of cellular respiration and potentiates Glucose stimulated insulin secretion which was abolished in pancreatic beta cells on cholesterol accumulation.

  8. Copper hypersensitivity

    DEFF Research Database (Denmark)

    Fage, Simon W; Faurschou, Annesofie; Thyssen, Jacob P

    2014-01-01

    hypersensitivity, a database search of PubMed was performed with the following terms: copper, dermatitis, allergic contact dermatitis, contact hypersensitivity, contact sensitization, contact allergy, patch test, dental, IUD, epidemiology, clinical, and experimental. Human exposure to copper is relatively common...

  9. Enhanced polyamine accumulation alters carotenoid metabolism at the transcriptional level in tomato fruit over-expressing spermidine synthase.

    Science.gov (United States)

    Neily, Mohamed Hichem; Matsukura, Chiaki; Maucourt, Mickaël; Bernillon, Stéphane; Deborde, Catherine; Moing, Annick; Yin, Yong-Gen; Saito, Takeshi; Mori, Kentaro; Asamizu, Erika; Rolin, Dominique; Moriguchi, Takaya; Ezura, Hiroshi

    2011-02-15

    Polyamines are involved in crucial plant physiological events, but their roles in fruit development remain unclear. We generated transgenic tomato plants that show a 1.5- to 2-fold increase in polyamine content by over-expressing the spermidine synthase gene, which encodes a key enzyme for polyamine biosynthesis. Pericarp-columella and placental tissue from transgenic tomato fruits were subjected to (1)H-nuclear magnetic resonance (NMR) for untargeted metabolic profiling and high-performance liquid chromatography-diode array detection for carotenoid profiling to determine the effects of high levels of polyamine accumulation on tomato fruit metabolism. A principal component analysis of the quantitative (1)H NMR data from immature green to red ripe fruit showed a clear discrimination between developmental stages, especially during ripening. Quantification of 37 metabolites in pericarp-columella and 41 metabolites in placenta tissues revealed distinct metabolic profiles between the wild type and transgenic lines, particularly at the late ripening stages. Notably, the transgenic tomato fruits also showed an increase in carotenoid accumulation, especially in lycopene (1.3- to 2.2-fold), and increased ethylene production (1.2- to 1.6-fold) compared to wild-type fruits. Genes responsible for lycopene biosynthesis, including phytoene synthase, phytoene desaturase, and deoxy-d-xylulose 5-phosphate synthase, were significantly up-regulated in ripe transgenic fruits, whereas genes involved in lycopene degradation, including lycopene-epsilon cyclase and lycopene beta cyclase, were down-regulated in the transgenic fruits compared to the wild type. These results suggest that a high level of accumulation of polyamines in the tomato regulates the steady-state level of transcription of genes responsible for the lycopene metabolic pathway, which results in a higher accumulation of lycopene in the fruit.

  10. Light attenuates lipid accumulation while enhancing cell proliferation and starch synthesis in the glucose-fed oleaginous microalga Chlorella zofingiensis.

    Science.gov (United States)

    Chen, Tianpeng; Liu, Jin; Guo, Bingbing; Ma, Xiaonian; Sun, Peipei; Liu, Bin; Chen, Feng

    2015-10-07

    The objective of this study was to investigate the effect of light on lipid and starch accumulation in the oleaginous green algae Chlorella zofingiensis supplemented with glucose. C. zofingiensis, when fed with 30 g/L glucose, synthesized lipids up to 0.531 g/g dry weight; while in the presence of light, the lipid content dropped down to 0.352 g/g dry weight. Lipid yield on glucose was 0.184 g/g glucose, 14% higher than that cultured with light. The light-mediated lipid reduction was accompanied by the down-regulation of fatty acid biosynthetic genes at the transcriptional level. Furthermore, light promoted cell proliferation, starch accumulation, and the starch yield based on glucose. Taken together, light may attenuate lipid accumulation, possibly through the inhibition of lipid biosynthetic pathway, leading to more carbon flux from glucose to starch. This study reveals the dual effects of light on the sugar-fed C. zofingiensis and provides valuable insights into the possible optimization of algal biomass and lipid production by manipulation of culture conditions.

  11. Interaction with Penicillium expansum enhances Botrytis cinerea growth in grape juice medium and prevents patulin accumulation in vitro.

    Science.gov (United States)

    Morales, H; Paterson, R R M; Venâncio, A; Lima, N

    2013-05-01

    Interactions between fungi occur when they grow on the same host plant. This is the case of Botrytis cinerea and Penicillium expansum on grape. P. expansum is also responsible for production of the mycotoxin patulin. In this study, the influence of the interaction between both fungi on fungal growth parameters was studied as well as the effect on the accumulation of patulin by P. expansum. For that purpose, spores of B. cinerea and P. expansum were inoculated together (mixed inoculum), and the parameters growth rate, time for growth and patulin accumulation were assessed. The presence of P. expansum conidia shortened the time for growth of mixed inoculum colonies which, at the end of incubation, were B. cinerea-like. Although some P. expansum growth was observed in mixed inoculum colonies, very low levels of patulin were observed. In assays carried out in patulin-spiked medium, B. cinerea was capable to metabolize the mycotoxin. The capabilities of B. cinerea to shorten time for growth and prevent patulin accumulation are competing abilities that facilitate grape colonization.

  12. Transgenic soya bean seeds accumulating β-carotene exhibit the collateral enhancements of oleate and protein content traits.

    Science.gov (United States)

    Schmidt, Monica A; Parrott, Wayne A; Hildebrand, David F; Berg, R Howard; Cooksey, Amanda; Pendarvis, Ken; He, Yonghua; McCarthy, Fiona; Herman, Eliot M

    2015-05-01

    Transgenic soya bean (Glycine max) plants overexpressing a seed-specific bacterial phytoene synthase gene from Pantoea ananatis modified to target to plastids accumulated 845 μg β carotene g(-1) dry seed weight with a desirable 12:1 ratio of β to α. The β carotene accumulating seeds exhibited a shift in oil composition increasing oleic acid with a concomitant decrease in linoleic acid and an increase in seed protein content by at least 4% (w/w). Elevated β-carotene accumulating soya bean cotyledons contain 40% the amount of abscisic acid compared to nontransgenic cotyledons. Proteomic and nontargeted metabolomic analysis of the mid-maturation β-carotene cotyledons compared to the nontransgenic did not reveal any significant differences that would account for the altered phenotypes of both elevated oleate and protein content. Transcriptomic analysis, confirmed by RT-PCR, revealed a number of significant differences in ABA-responsive transcripton factor gene expression in the crtB transgenics compared to nontransgenic cotyledons of the same maturation stage. The altered seed composition traits seem to be attributed to altered ABA hormone levels varying transcription factor expression. The elevated β-carotene, oleic acid and protein traits in the β-carotene soya beans confer a substantial additive nutritional quality to soya beans. © 2014 Society for Experimental Biology, Association of Applied Biologists and John Wiley & Sons Ltd.

  13. A hybrid surface modification method on copper wire braids for enhancing thermal performance of ultra-thin heat pipes

    Science.gov (United States)

    Sheng, W. K.; Lin, H. T.; Wu, C. H.; Kuo, L. S.; Chen, P. H.

    2017-02-01

    Copper is the most widely used material in heat pipe manufacturing. Since the capability of wick structures inside a heat pipe will dominate its thermal performance, in this study, we introduce a hybrid surface modification method on the copper wire braids being inserted as wick structure into an ultra-thin heat pipe. The hybrid method is the combination of a chemical-oxidation-based method and a sol-gel method with nanoparticles being dip-coated onto the braid. The experimental data show that braids under hybrid treatment perform higher water rising speed than the oxidized braids while owning higher water net weight than those braids being only dip-coated with nanoparticle.

  14. Differential pulse voltammetric determination of metformin using copper-loaded activated charcoal modified electrode.

    Science.gov (United States)

    Gholivand, Mohammad Bagher; Mohammadi-Behzad, Leila

    2013-07-01

    A simple and sensitive carbon paste electrode has been developed for the electrochemical trace determination of metformin (MET). This sensor was designed by Copper(II)-loaded activated charcoal (Cu-AC) in the carbon paste electrode (CPE), which provides remarkably improved sensitivity and selectivity for the electrochemical stripping assay of MET. The drug was accumulated on the surface of the electrode through formation of a coordination complex with copper ions, which enhanced the sensitivity of the method. The effects of various copper(II) salts and oxidation states of copper (within the carbon paste electrode) on MET oxidation behavior were also investigated. The calibration graph was linear over the concentration range of 50 nM to 60 μM MET, and the detection limit was calculated as 9 nM. The proposed electrode was used successfully for MET determination in real matrices.

  15. Proteomics analysis for enhanced lipid accumulation in oleaginous Chlorella vulgaris under a heterotrophic-Na⁺ induction two-step regime.

    Science.gov (United States)

    Li, Yuqin; Mu, Jinxiu; Chen, Di; Xu, Hua; Han, Fangxin; Feng, Bo; Zeng, Hongyan

    2015-05-01

    A heterotrophic-Na(+) induction (HNI) two-step regime was developed to enhance lipid accumulation in oleaginous Chlorella vulgaris. C. vulgaris was cultivated heterotrophically to a biomass of 7.8 g l(-1) in 120 h. The cells were re-suspended in fresh media supplemented with 0.5 M NaCl followed by 12 h growth to accumulate lipid to 53.4 % (w/w). The lipid productivity (625 mg l(-1) day(-1)) achieved with HNI was better than that using heterotrophy alone (405 mg l(-1) day(-1)). To promote possible applications of HNI strategy in other microalgal species, the lipid triggers and potential molecular pathways associated with lipid biosynthesis were investigated. Malic enzyme and acyl-CoA-binding protein were key metabolic checkpoints found to modulate lipid biosynthesis in cells. These results provide the foundation to develop high-lipid engineering miroalgae for industrialization of biodiesel.

  16. Engineering metal-binding sites of bacterial CusF to enhance Zn/Cd accumulation and resistance by subcellular targeting

    Energy Technology Data Exchange (ETDEWEB)

    Yu, Pengli; Yuan, Jinhong [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Zhang, Hui [Key Laboratory of Plant Molecular Physiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Deng, Xin [Department of Chemistry and Institute for Biophysical Dynamics, The University of Chicago, Chicago, IL 60637 (United States); Ma, Mi [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China); Zhang, Haiyan, E-mail: hyz@ibcas.ac.cn [Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093 (China)

    2016-01-25

    Highlights: • mCusF is specifically targeted to different subcellular compartments in Arabidopsis. • Plants expressing vacuole-targeted mCusF exhibit strongest Zn resistance. • All transgenic lines accumulate more Zn under Zn exposure. • All transgenic lines enhance root-to-shoot translocation of Cd. • Metal homeostasis is improved in mCusF plants under Cd exposure. - Abstract: The periplasmic protein CusF acts as a metallochaperone to mediate Cu resistance in Escherichia coli. CusF does not contain cysteine residues and barely binds to divalent cations. Here, we addressed effects of cysteine-substitution mutant (named as mCusF) of CusF on zinc/cadmium (Zn/Cd) accumulation and resistance. We targeted mCusF to different subcellular compartments in Arabidopsis. We found that plants expressing vacuole-targeted mCusF were more resistant to excess Zn than WT and plants with cell wall-targeted or cytoplasmic mCusF. Under long-term exposure to excess Zn, all transgenic lines accumulated more Zn (up to 2.3-fold) in shoots than the untransformed plants. Importantly, plants with cytoplasmic mCusF showed higher efficiency of Zn translocation from root to shoot than plants with secretory pathway-targeted-mCusF. Furthermore, the transgenic lines exhibited enhanced resistance to Cd and significant increase in root-to-shoot Cd translocation. We also found all transgenic plants greatly improved manganese (Mn) and iron (Fe) homeostasis under Cd exposure. Our results demonstrate heterologous expression of mCusF could be used to engineer a new phytoremediation strategy for Zn/Cd and our finding also deepen our insights into mechanistic basis for relieving Cd toxicity in plants through proper root/shoot partitioning mechanism and homeostatic accumulation of Mn and Fe.

  17. The link between copper and Wilson's disease.

    Science.gov (United States)

    Purchase, Rupert

    2013-01-01

    Wilson's disease (hepatolenticular degeneration) is a rare inherited autosomal recessive disorder of copper metabolism leading to copper accumulation in the liver and extrahepatic organs such as the brain and cornea. Patients may present with combinations of hepatic, neurological and psychiatric symptoms. Copper is the therapeutic target for the treatment of Wilson's disease. But how did copper come to be linked with Wilson's disease? The answer encompasses a study of enzootic neonatal ataxia in lambs in the 1930s, the copper-chelating properties of British Anti-Lewisite, and the chemical analysis for copper of the organs of deceased Wilson's disease patients in the mid-to-late 1940s. Wilson's disease is one of a number of copper-related disorders where loss of copper homeostasis as a result of genetic, nutritional or environmental factors affects human health.

  18. Coexistence of Copper in the Iron-Rich Particles of Aceruloplasminemia Brain.

    Science.gov (United States)

    Yoshida, Kunihiro; Hayashi, Hisao; Wakusawa, Shinya; Shigemasa, Ryota; Koide, Ryoji; Ishikawa, Tetsuya; Tatsumi, Yasuaki; Kato, Koichi; Ohara, Shinji; Ikeda, Shu-Ichi

    2017-01-01

    The interaction between iron and copper has been discussed in association with human health and diseases for many years. Ceruloplasmin, a multi-copper oxidase, is mainly involved in iron metabolism and its genetic defect, aceruloplasminemia (ACP), shows neurological disorders and diabetes associated with excessive iron accumulation, but little is known about the state of copper in the brain. Here, we investigated localization of these metals in the brains of three patients with ACP using electron microscopes equipped with an energy-dispersive x-ray analyzer. Histochemically, iron deposition was observed mainly in the basal ganglia and dentate nucleus, and to lesser degree in the cerebral cortex of the patients, whereas copper grains were not detected. X-ray microanalysis identified two types of iron-rich particles in their brains: dense bodies, namely hemosiderins, and their aggregated inclusions. A small number of hemosiderins and most inclusions contained a significant amount of copper which was enough for distinct Cu x-ray images. These copper-containing particles were observed more frequently in the putamen and dentate nucleus than the cerebral cortex. Coexistence of iron and copper was supported by good correlations in the molecular ratios between these two metals in iron-rich particles with Cu x-ray image. Iron-dependent copper accumulation in iron-rich particles may suggest that copper recycling is enhanced to meet the increased requirement of cuproproteins in iron overload brain. In conclusion, the iron-rich particles with Cu x-ray image were found in the ACP brain.

  19. Zinc-bearing zeolite clinoptilolite improves tissue zinc accumulation in laying hens by enhancing zinc transporter gene mRNA abundance.

    Science.gov (United States)

    Li, Linfeng; Li, Ping; Chen, Yueping; Wen, Chao; Zhuang, Su; Zhou, Yanmin

    2015-08-01

    A study was conducted to investigate effects of zinc-bearing zeolite clinoptilolite (ZnCP), as an alternative for zinc sulfate (ZnSO4), on laying performance, tissue Zn accumulation and Zn transporter genes expression in laying hens. Hy-Line Brown laying hens were allocated to three treatments, each of which had six replicates with 15 hens per replicate, receiving basal diet supplemented with ZnSO4 (control, 80 mg Zn/kg diet), 0.23% ZnCP (40.25 mg Zn/kg diet) and 0.46% ZnCP (80.50 mg Zn/kg diet) for 8 weeks, respectively. Compared with control, hens fed diet containing 0.23% ZnCP had similar Zn content in measured tissues (P > 0.05). A higher ZnCP inclusion (0.46%) enhanced Zn accumulation in liver (P < 0.05) and pancreas (P < 0.05). In addition, ZnCP inclusion increased blood iron (Fe) content (P < 0.05). ZnCP supplementation enhanced jejunal metallothionein-4 (MT-4) messenger RNA (mRNA) abundance (P < 0.05). ZnCP inclusion at a higher level (0.46%) increased mRNA expression of MT-4 in pancreas (P < 0.05) and zinc transporter-1 (ZnT-1) in jejunum (P < 0.05). The highest ZnT-2 mRNA abundance in jejunum was found in hens fed 0.23% ZnCP inclusion diet (P < 0.05). The results indicated that ZnCP reached a higher bioavailability as compared with ZnSO4 as evidenced by enhanced tissue Zn accumulation and Zn transporter genes expression.

  20. Fluorescence enhancement of CdTe/CdS quantum dots by coupling of glyphosate and its application for sensitive detection of copper ion

    Energy Technology Data Exchange (ETDEWEB)

    Liu Zhengqing; Liu Shaopu; Yin Pengfei [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China); He Youqiu, E-mail: heyq@swu.edu.cn [Key Laboratory on Luminescence and Real-Time Analysis, Ministry of Education, School of Chemistry and Chemical Engineering, Southwest University, Chongqing 400715 (China)

    2012-10-01

    Graphical abstract: Glyphosate (Glyp) had been used to modify the surface of CdTe/CdS QDs, resulting in the enhancement of fluorescence intensity. The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+} based on the fluorescence quenching. Highlights: Black-Right-Pointing-Pointer Water soluble CdTe/CdS quantum dots capped with glyphosate were firstly synthesized. Black-Right-Pointing-Pointer The fluorescence of the Glyp-functionalized QDs was quenched by copper ion. Black-Right-Pointing-Pointer A new fluorescent sensor for copper ion was developed based on the prepared QDs. Black-Right-Pointing-Pointer The sensor exhibited high sensitivity and good selectivity for copper ion. - Abstract: A novel fluorescent probe for Cu{sup 2+} determination based on the fluorescence quenching of glyphosate (Glyp)-functionalized quantum dots (QDs) was firstly reported. Glyp had been used to modify the surface of QDs to form Glyp-functionalized QDs following the capping of thioglycolic acid on the core-shell CdTe/CdS QDs. Under the optimal conditions, the response was linearly proportional to the concentration of Cu{sup 2+} between 2.4 Multiplication-Sign 10{sup -2} {mu}g mL{sup -1} and 28 {mu}g mL{sup -1}, with a detection limit of 1.3 Multiplication-Sign 10{sup -3} {mu}g mL{sup -1} (3{delta}). The Glyp-functionalized QDs fluorescent probe offers good sensitivity and selectivity for detecting Cu{sup 2+}. The fluorescent probe was successfully used for the determination of Cu{sup 2+} in environmental samples. The mechanism of reaction was also discussed.

  1. Accumulation of phosphorylated beta-catenin enhances ROS-induced cell death in presenilin-deficient cells.

    Directory of Open Access Journals (Sweden)

    Jung H Boo

    Full Text Available Presenilin (PS is involved in many cellular events under physiological and pathological conditions. Previous reports have revealed that PS deficiency results in hyperproliferation and resistance to apoptotic cell death. In the present study, we investigated the effects of PS on beta-catenin and cell mortality during serum deprivation. Under these conditions, PS1/PS2 double-knockout MEFs showed aberrant accumulation of phospho-beta-catenin, higher ROS generation, and notable cell death. Inhibition of beta-catenin phosphorylation by LiCl reversed ROS generation and cell death in PS deficient cells. In addition, the K19/49R mutant form of beta-catenin, which undergoes normal phosphorylation but not ubiquitination, induced cytotoxicity, while the phosphorylation deficient S37A beta-catenin mutant failed to induce cytotoxicity. These results indicate that aberrant accumulation of phospho-beta-catenin underlies ROS-mediated cell death in the absence of PS. We propose that the regulation of beta-catenin is useful for identifying therapeutic targets of hyperproliferative diseases and other degenerative conditions.

  2. Influence of nitrite accumulation on "Candidatus Accumulibacter" population structure and enhanced biological phosphorus removal from municipal wastewater.

    Science.gov (United States)

    Zeng, Wei; Li, Boxiao; Wang, Xiangdong; Bai, Xinlong; Peng, Yongzhen

    2016-02-01

    A modified University of Cape Town (MUCT) process was used to treat real municipal wastewater with low carbon to nitrogen ratio (C/N). To our knowledge, this is the first study where the influence of nitrite accumulation on "Candidatus Accumulibacter" clade-level population structure was investigated during nitritation establishment and destruction. Real time quantitative PCR assays were conducted using the polyphosphate kinase 1 gene (ppk1) as a genetic marker. Abundances of total "Candidatus Accumulibacter", the relative distributions and population structure of the five "Candidatus Accumulibacter" clades were characterized. Under complete nitrification, clade I using nitrate as electron acceptor was below 5% of total "Candidatus Accumulibacter". When the reactor was transformed into nitritation, clade I gradually disappeared. Clade IID using nitrite as electron acceptor for denitrifying phosphorus (P) removal was always the dominant "Candidatus Accumulibacter" throughout the operational period. This clade was above 90% on average in total "Candidatus Accumulibacter", even up to nearly 100%, which was associated with good performance of denitrifying P removal via nitrite pathway. The nitrite concentrations affected the abundance of clade IID. The P removal was mainly completed by anoxic P uptake of about 88%. The P removal efficiency clearly had a positive correlation with the nitrite accumulation ratio. Under nitritation, the P removal efficiency was 30% higher than that under complete nitrification, suggesting that nitrite was appropriate as electron acceptor for denitrifying P removal when treating carbon-limited wastewater. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

  3. Green engineered biomolecule-capped silver and copper nanohybrids using Prosopis cineraria leaf extract: Enhanced antibacterial activity against microbial pathogens of public health relevance and cytotoxicity on human breast cancer cells (MCF-7).

    Science.gov (United States)

    Jinu, U; Gomathi, M; Saiqa, I; Geetha, N; Benelli, G; Venkatachalam, P

    2017-02-16

    This research focused on green engineering and characterization of silver (PcAgNPs) and copper nanoparticles (PcCuNPs) using Prosopis cineraria (Pc) leaf extract prepared by using microwave irradiation. We studied their enhanced antimicrobial activity on human pathogens as well as cytotoxicity on breast cancer cells (MCF-7). Biofabricated silver and copper nanoparticles exhibited UV-Visible absorbance peaks at 420 nm and 575 nm, confirming the bioreduction and stabilization of nanoparticles. Nanoparticles were characterized by FTIR, XRD, FESEM, and EDX analysis. FTIR results indicated the presence of alcohols, alkanes, aromatics, phenols, ethers, benzene, amines and amides that were possibly involved in the reduction and capping of silver and copper ions. XRD analysis was performed to confirm the crystalline nature of the silver and copper nanoparticles. FESEM analysis suggested that the nanoparticles were hexagonal or spherical in shape with size ranging from 20 to 44.49 nm and 18.9-32.09 nm for AgNPs and CuNPs, respectively. EDX analysis confirmed the presence of silver and copper elemental signals in the nanoparticles. The bioengineered silver and copper nanohybrids showed enhanced antimicrobial activity against Gram-positive and Gram-negative MDR human pathogens. MTT assay results indicated that CuNPs show potential cytotoxic effect followed by AgNPs against MCF-7 cancer cell line. IC50 were 65.27 μg/ml, 37.02 μg/ml and 197.3 μg/ml for PcAgNPs, PcCuNPs and P. cineraria leaf extracts, respectively, treated MCF-7 cells. The present investigation highlighted an effective protocol for microwave-assisted synthesis of biomolecule-loaded silver and copper nanoparticles with enhanced antibacterial and anticancer activity. Results strongly suggested that bioengineered AgNPs and CuNPs could be used as potential tools against microbial pathogens and cancer cells.

  4. Cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) removal and hydrogen evolution in bioelectrochemical systems.

    Science.gov (United States)

    Wang, Qiang; Huang, Liping; Pan, Yuzhen; Zhou, Peng; Quan, Xie; Logan, Bruce E; Chen, Hongbo

    2016-01-01

    Bioelectrochemical systems (BESs) were first operated in microbial fuel cell mode for recovering Cu(II), and then shifted to microbial electrolysis cells for Cd(II) reduction on the same cathodes of titanium sheet (TS), nickel foam (NF) or carbon cloth (CC). Cu(II) reduction was similar to all materials (4.79-4.88mg/Lh) whereas CC exhibited the best Cd(II) reduction (5.86±0.25mg/Lh) and hydrogen evolution (0.35±0.07m(3)/m(3)d), followed by TS (5.27±0.43mg/Lh and 0.15±0.02m(3)/m(3)d) and NF (4.96±0.48mg/Lh and 0.80±0.07m(3)/m(3)d). These values were higher than no copper controls by factors of 2.0 and 5.0 (TS), 4.2 and 2.0 (NF), and 1.8 and 7.0 (CC). These results demonstrated cooperative cathode electrode and in situ deposited copper for subsequent enhanced Cd(II) reduction and hydrogen production in BESs, providing an alternative approach for efficiently remediating Cu(II) and Cd(II) co-contamination with simultaneous hydrogen production.

  5. Kartogenin, transforming growth factor-β1 and bone morphogenetic protein-7 coordinately enhance lubricin accumulation in bone-derived mesenchymal stem cells.

    Science.gov (United States)

    Liu, Chun; Ma, Xueqin; Li, Tao; Zhang, Qiqing

    2015-09-01

    Osteoarthritis, a common joint degeneration, can cause breakdown of articular cartilage with the presence of lubricin metabolic abnormalities. Lubricin is a multi-level chondroprotective mucinous glycoprotein in articular joints. Joint defect and infection is elevated and accompanied by accelerated cartilage lesions involving degradation and loss of lubricin. However, a novel, heterocyclic compound called kartogenin (KGN) was discovered to stimulate chondrogenic differentiation of bone-derived mesenchymal stem cells (BMSCs). And the synergistic effect of transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-7 (BMP-7) could provoke lubricin accumulation. This paper attempted to explore the connection between accumulation of lubricin and the effect of TGF-β1, BMP-7 and/or KGN. Hence, we investigated the expression and secretion of lubricin in BMSCs treated with different combinations of TGF-β1, BMP-7, and/or KGN. Using an in vitro BMSCs system, we observed the content of lubricin from BMSCs treated with TGF-β1, BMP-7, and KGN was the highest at both the protein level and the gene level. The accumulation of lubricin was enhanced coordinately by the increase of synthesis and decrease of degradation possibly via c-Myc and adamts5 pathway. These results further suggested that supplementation of the defect parts with lubricin by using growth factors and small molecules showed a promising potential on preventing joint deterioration in patients with acquired or genetic deficiency of lubricin in the future of regenerative medicine.

  6. Expression of a vacuole-localized BURP-domain protein from soybean (SALI3-2 enhances tolerance to cadmium and copper stresses.

    Directory of Open Access Journals (Sweden)

    Yulin Tang

    Full Text Available The plant-specific BURP family proteins play diverse roles in plant development and stress responses, but the function mechanism of these proteins is still poorly understood. Proteins in this family are characterized by a highly conserved BURP domain with four conserved Cys-His repeats and two other Cys, indicating that these proteins potentially interacts with metal ions. In this paper, an immobilized metal affinity chromatography (IMAC assay showed that the soybean BURP protein SALI3-2 could bind soft transition metal ions (Cd(2+, Co(2+, Ni(2+, Zn(2+ and Cu(2+ but not hard metal ions (Ca(2+ and Mg(2+ in vitro. A subcellular localization analysis by confocal laser scanning microscopy revealed that the SALI3-2-GFP fusion protein was localized to the vacuoles. Physiological indexes assay showed that Sali3-2-transgenic Arabidopsis thaliana seedlings were more tolerant to Cu(2+ or Cd(2+ stresses than the wild type. An inductively coupled plasma optical emission spectrometry (ICP-OES analysis illustrated that, compared to the wild type seedlings the Sali3-2-transgenic seedlings accumulated more cadmium or copper in the roots but less in the upper ground tissues when the seedlings were exposed to excessive CuCl2 or CdCl2 stress. Therefore, our findings suggest that the SALI3-2 protein may confer cadmium (Cd(2+ and copper (Cu(2+ tolerance to plants by helping plants to sequester Cd(2+ or Cu(2+ in the root and reduce the amount of heavy metals transported to the shoots.

  7. Identification of QTLs that enhance the nutritional value of rice grain and limit accumulation of undesirable elements such as arsenic

    Science.gov (United States)

    Research into the mineral contents of cereal grains and vegetables is motivated by interest in improving their nutritional value. Biofortification refers to natural enhancement of grain/food products through traditional breeding. Since this approach does not require genetic engineering, it is acce...

  8. Characterization of a Marine Microbial Community Used for Enhanced Sulfate Reduction and Copper Precipitation in a Two-Step Process.

    Science.gov (United States)

    García-Depraect, Octavio; Guerrero-Barajas, Claudia; Jan-Roblero, Janet; Ordaz, Alberto

    2017-06-01

    Marine microorganisms that are obtained from hydrothermal vent sediments present a great metabolic potential for applications in environmental biotechnology. However, the work done regarding their applications in engineered systems is still scarce. Hence, in this work, the sulfate reduction process carried out by a marine microbial community in an upflow anaerobic sludge blanket (UASB) reactor was investigated for 190 days under sequential batch mode. The effects of 1000 to 5500 mg L(-1) of SO4(-2) and the chemical oxygen demand (COD)/SO4(-2) ratio were studied along with a kinetic characterization with lactate as the electron donor. Also, the feasibility of using the sulfide produced in the UASB for copper precipitation in a second column was studied under continuous mode. The system presented here is an alternative to sulfidogenesis, particularly when it is necessary to avoid toxicity to sulfide and competition with methanogens. The bioreactor performed better with relatively low concentrations of sulfate (up to 1100 mg L(-1)) and COD/SO4(-2) ratios between 1.4 and 3.6. Under the continuous regime, the biogenic sulfide was sufficient to precipitate copper at a removal rate of 234 mg L(-1) day(-1). Finally, the identification of the microorganisms in the sludge was carried out; some genera of microorganisms identified were Desulfitobacterium and Clostridium.

  9. Overwhelming reaction enhanced by ultrasonics during brazing of alumina to copper in air by Zn-14Al hypereutectic filler.

    Science.gov (United States)

    Ji, Hongjun; Chen, Hao; Li, Mingyu

    2017-03-01

    The ultrasonic-assisted brazing of α-alumina to copper was achieved in air without flux using Zn-14wt%Al hypereutectic filler at 753K within tens of seconds. The effects of ultrasonic time on the microstructures and mechanical properties of joints were investigated. In the joint interlayer, large amounts of intermetallic phases consisted of binary CuZn5 embedded by many ternary Al4.2Cu3.2Zn0.7 particles were formed. At the ceramic interface, newly formed crystalline Al2O3 aggregated. At the Cu interface, acoustic corrosion on the copper resulted in depriving the surface oxides and forming many pits on its surface, which provided saturated Cu in the melted filler alloys during the brazing. The ultrasonic vibrations had distinct effects on the metallurgical reactions of the joints, resulting in intermetallic-phase-filled composite joints with shear strength of 66MPa. The overgrowth of intermetallic compounds, the newly formed crystalline alumina, and the acoustic pits was probably ascribed to the ultrasonic effects.

  10. 铜对伴矿景天生长及锌镉吸收性的影响%Effects of Copper on Growth and Zinc and Cadmium Accumulation of Sedum plumbizincicola

    Institute of Scientific and Technical Information of China (English)

    李柱; 任婧; 杨冰凡; 王松凤; 吴龙华; 骆永明

    2012-01-01

    利用植物生长室水培试验和温室土培盆栽试验相结合,研究了Cu对Zn、Cd超积累植物伴矿景天生长及Zn、Cd吸收性的影响.水培试验结果显示,0.31~50μmol/L Cu处理14天对伴矿景天生长及对Zn、Cd吸收性没有显著影响;但1 00 μmol/L Cu处理显著抑制植物生长,降低地上部Zn、Cd及根中Cd浓度,对根中Zn浓度变化没有显著影响.盆栽试验结果发现,在土壤Cu仅为3.61 mg/kg时伴矿景天生长不良,外加Cu显著促进其生长并随Cu浓度升高效应增加:但施用3 mmol/kgEDDS和再次外加250 mg/kg Cu处理使伴矿景天因体内Cu积累量过高而导致明显毒害,地上部Cu最高达1068 mg/kg.可见低量Cu处理可促进伴矿景天生长,利于植物对土壤Zn、Cd的吸取修复,但土壤中Cu浓度过高将抑制Zn、Cd超积累植物的生长,降低其Zn、Cd吸收能力,在利用该Zn、Cd超积累植物修复高Cu的Zn和Cd污染土壤时应采取适当措施降低Cu毒害效应.%Growth chamber hydroponics culture and glass house pot experiment were conducted to study the effects of copper on the growth of Sedum plumbtzincicoh plant and its accumulations of Zn and Cd. The results from the hydroponics culture showed that there was no significant difference on the growth and Zn and Cd concentrations of Sedum plant among the treatments of low solution Cu concentrations (0.31-SO umol/L), but 100 umol/L solution Cu inhibited plant growth and Cd and Zn accumulations in plant shoot. The glass house pot experiment results showed that sedum plant grew slowly in soil at low Cu (3.61 mg/kg) concentration, however, the addition of Cu promoted its growth. The application of 3 mmol/kg EDDS and 250 mg/kg Cu led the greater accumulation of Cu in plant, with the highest Cu concentration of 1 068 mg/kg, which may be responsible for plant injury and leaves fallen down. These results showed that low concentration of Cu benefits the plant growth and the phytoextraction of Zn and Cd from

  11. Modulation of tau phosphorylation by environmental copper

    OpenAIRE

    Voss, Kellen; Harris, Christopher; Ralle, Martina; Duffy, Megan; Murchison, Charles; Joseph F. Quinn

    2014-01-01

    Background The transition metal copper enhances amyloid β aggregation and neurotoxicity, and in models of concomitant amyloid and tau pathology, copper also promotes tau aggregation. Since it is not clear if the effects of environmental copper upon tau pathology are dependent on the presence of pathological amyloid β, we tested the effects of copper overload and complexing in disease models which lack pathological amyloid β. Methods We used cell culture and transgenic murine models to test th...

  12. Molecular breeding of a novel orange-brown tomato fruit with enhanced beta-carotene and chlorophyll accumulation.

    Science.gov (United States)

    Manoharan, Ranjith Kumar; Jung, Hee-Jeong; Hwang, Indeok; Jeong, Namhee; Kho, Kang Hee; Chung, Mi-Young; Nou, Ill-Sup

    2017-01-01

    Tomatoes provide a significant dietary source of the carotenoids, lycopene and β-carotene. During ripening, carotenoid accumulation determines the fruit colors while chlorophyll degradation. These traits have been, and continue to be, a significant focus for plant breeding efforts. Previous work has found strong evidence for a relationship between CYC-B gene expression and the orange color of fleshy fruit. Other work has identified a point mutation in SGR that impedes chlorophyll degradation and causes brown flesh color to be retained in some tomato varieties. We crossed two inbred lines, KNY2 (orange) and KNB1 (brown) and evaluated the relationship between these genes for their effect on fruit color. Phenotypes of F2 generation plants were analyzed and a novel 'orange-brown' fruit color was identified. We confirm two SNPs, one in CYC-B and another in SGR gene sequence, associated with segregation of 'orange-brown' fruit color in F2 generation. The carotenoid and chlorophyll content of a fleshy fruit was assessed across the different phenotypes and showed a strong correlation with expression pattern of carotenoid biosynthesis genes and SGR function. The orange-brown fruit has high β-carotene and chlorophyll. Our results provide valuable information for breeders to develop tomato fruit of a novel color using molecular markers.

  13. Carbon dioxide-enriched atmosphere enhances biomass accumulation and meristem production in the pioneer shrub Baccharis dracunculifolia (Asteraceae

    Directory of Open Access Journals (Sweden)

    Camila Emiliane Mendes de Sá

    2014-12-01

    Full Text Available The increase in atmospheric CO2 concentration predicted to the end of this century may cause several alterations on plant species development, which shall result in changes in the structure and function of plant communities. The present work aimed to investigate the effects of the increase in atmospheric CO2 concentration on the development of Baccharis dracunculifolia, a key pioneer Neotropical shrub. Seedlings of B. dracunculifolia were exposed to 720 ppm of CO2 as well as to ambient concentration of CO2 (approximately 360 ppm during 120 days in open top chambers. Growth and dry biomass accumulation were higher under elevated CO2 concentrations. As a response to CO2 enrichment, there was an increase of 134% in total dry mass, 208% in root dry mass and 152% in stem dry mass. The shrubby habit of B. dracunculifolia and the larger number of meristems produced under high CO2 promoted the increase in 137% in the number of branches. The present study contributes to the knowledge about how pioneer tropical plants may respond to increased atmospheric [CO2] in environments with low nutrient limitation.

  14. Simultaneous synthesis of nanodiamonds and graphene via plasma enhanced chemical vapor deposition (MW PE-CVD) on copper.

    Science.gov (United States)

    Gottlieb, Steven; Wöhrl, Nicolas; Schulz, Stephan; Buck, Volker

    2016-01-01

    The simultaneous growth of both nanodiamonds and graphene on copper samples is described for the first time. A PE-CVD process is used to synthesize graphene layers and nanodiamond clusters from a hydrogen/methane gas mixture as it is typically done successfully in thermal CVD processes for graphene synthesis. However, the standard thermal CVD process is not without problems since the deposition of graphene is affected by the evaporation of a notable amount of copper caused by the slow temperature increase typical for thermal CVD resulting in a long process time. In sharp contrast, the synthesis of graphene by PE-CVD can circumvent this problem by substantially shortening the process time at holding out the prospect of a lower substrate temperature. The reduced thermal load and the possibility to industrially scale-up the PE-CVD process makes it a very attractive alternative to the thermal CVD process with respect to the graphene production in the future. Nanodiamonds are synthesized in PE-CVD reactors for a long time because these processes offer a high degree of control over the film's nanostructure and simultaneously providing a significant high deposition rate. To model the co-deposition process, the three relevant macroscopic parameters (pressure, gas mixture and microwave power) are correlated with three relevant process properties (plasma ball size, substrate temperature and C2/Hα-ratio) and the influence on the quality of the deposited carbon allotropes is investigated. For the evaluation of the graphene as well as the nanodiamond quality, Raman spectroscopy used whereas the plasma properties are measured by optical methods. It is found that the diamond nucleation can be influenced by the C2/Hα-ratio in the plasma, while the graphene quality remains mostly unchanged by this parameter. Moreover it is derived from the experimental data that the direct plasma contact with the copper surface is beneficial for the nucleation of the diamond while the growth and

  15. Enhancement of laccase activity through the construction and breakdown of a hydrogen bond at the type I copper center in Escherichia coli CueO and the deletion mutant Δα5-7 CueO.

    Science.gov (United States)

    Kataoka, Kunishige; Hirota, Shun; Maeda, Yasuo; Kogi, Hiroki; Shinohara, Naoya; Sekimoto, Madoka; Sakurai, Takeshi

    2011-02-01

    CueO is a multicopper oxidase involved in a copper efflux system of Escherichia coli and has high cuprous oxidase activity but little or no oxidizing activity toward various organic substances. However, its activity toward oxidization of organic substrates was found to be considerably increased by the removal of the methionine-rich helical segment that covers the substrate-binding site (Δα5-7 CueO) [Kataoka, K., et al. (2007) J. Mol. Biol. 373, 141]. In the study presented here, mutations at Pro444 to construct a second NH-S hydrogen bond between the backbone amide and coordinating Cys500 thiolate of the type I copper are shown to result in positive shifts in the redox potential of this copper center and enhanced oxidase activity in CueO. Analogous enhancement of the activity of Δα5-7 CueO has been identified only in the Pro444Gly mutant because Pro444 mutants limit the incorporation of copper ions into the trinuclear copper center. The activities of both CueO and Δα5-7 CueO were also enhanced by mutations to break down the hydrogen bond between the imidazole group of His443 that is coordinated to the type I copper and the β-carboxy group of Asp439 that is located in the outer sphere of the type I copper center. A synergetic effect of the positive shift in the redox potential of the type I copper center and the increase in enzyme activity has been achieved by the double mutation of Pro444 and Asp439 of CueO. Absorption, circular dichroism, and resonance Raman spectra indicate that the characteristics of the Cu(II)-S(Cys) bond were only minimally perturbed by mutations involving formation or disruption of a hydrogen bond from the coordinating groups to the type I copper. This study provides widely applicable strategies for tuning the activities of multicopper oxidases.

  16. Heat transfer enhancement of fin-copper foam composite structure%翅片-泡沫铜复合结构的导热增强作用

    Institute of Scientific and Technical Information of China (English)

    迟蓬涛; 高红霞; 余建祖; 谢永奇

    2012-01-01

    As the fins can significantly enhance the thermal conducting capability along the fin extending direction,the concept of combining fins with copper foam as thermal conductivity enhancer was proposed to satisfy the heat rejection requirements of some high-power electronic components used in the aviation.Fin-copper foam/paraffin samples with fin thicknesses of 0.5,0.8 and 1.0mm were processed.The thermal performances of the samples were tested via steady and transient experiments.The results suggest that the effective conductivity of composite material with 1.0mm fin reaches 11.4W/(m·K),which is 3.7 times as that of the copper foam/paraffin and 42.2 times as that of the pure paraffin.Under the same heat flux,the maximum temperature differences of the samples with fins are reduced by 73.2%-90.0%.The tests verify that the effective thermal conductivity and the dynamic thermal response of copper foam/paraffin can be remarkably enhanced by fins.A correlation of the non-dimensional coefficients is raised via the experimental results.%由于翅片能够极大提高沿翅片伸展方向的导热能力,因此为满足一些航空大功率元件的散热要求,提出采用翅片-泡沫铜复合结构作为导热增强介质的概念.制作了翅片厚度分别为0.5,0.8mm和1.0mm的翅片-泡沫铜/石蜡实验件.通过瞬态和稳态的方法对实验件的热特性进行了测试,结果表明添加1.0mm翅片后复合材料的等效导热系数达到11.4W/(m.K),分别为泡沫铜/石蜡和纯石蜡的3.7倍和42.2倍;在相同热流密度下,采用翅片的装置热源与散热面的最大温差相对于未采用翅片的装置降低了73.2%~90.0%.实验证明翅片能够显著提高泡沫铜/石蜡的等效导热系数和动态热响应速度.根据实验结果提出了适用于翅片-泡沫铜/石蜡相变过程的无量纲数关联式.

  17. Enhanced accumulation of carotenoids in sweetpotato plants overexpressing IbOr-Ins gene in purple-fleshed sweetpotato cultivar.

    Science.gov (United States)

    Park, Sung-Chul; Kim, Sun Ha; Park, Seyeon; Lee, Hyeong-Un; Lee, Joon Seol; Park, Woo Sung; Ahn, Mi-Jeong; Kim, Yun-Hee; Jeong, Jae Cheol; Lee, Haeng-Soon; Kwak, Sang-Soo

    2015-01-01

    Sweetpotato [Ipomoea batatas (L.) Lam] is an important root crop that produces low molecular weight antioxidants such as carotenoids and anthocyanin. The sweetpotato orange (IbOr) protein is involved in the accumulation of carotenoids. To increase the levels of carotenoids in the storage roots of sweetpotato, we generated transgenic sweetpotato plants overexpressing IbOr-Ins under the control of the cauliflower mosaic virus (CaMV) 35S promoter in an anthocyanin-rich purple-fleshed cultivar (referred to as IbOr plants). IbOr plants exhibited increased carotenoid levels (up to 7-fold) in their storage roots compared to wild type (WT) plants, as revealed by HPLC analysis. The carotenoid contents of IbOr plants were positively correlated with IbOr transcript levels. The levels of zeaxanthin were ∼ 12 times elevated in IbOr plants, whereas β-carotene increased ∼ 1.75 times higher than those of WT. Quantitative RT-PCR analysis revealed that most carotenoid biosynthetic pathway genes were up-regulated in the IbOr plants, including PDS, ZDS, LCY-β, CHY-β, ZEP and Pftf, whereas LCY-ɛ was down-regulated. Interestingly, CCD1, CCD4 and NCED, which are related to the degradation of carotenoids, were also up-regulated in the IbOr plants. Anthocyanin contents and transcription levels of associated biosynthetic genes seemed to be altered in the IbOr plants. The yields of storage roots and aerial parts of IbOr plants and WT plants were not significantly different under field cultivation. Taken together, these results indicate that overexpression of IbOr-Ins can increase the carotenoid contents of sweetpotato storage roots.

  18. VLDL from Metabolic Syndrome Individuals Enhanced Lipid Accumulation in Atria with Association of Susceptibility to Atrial Fibrillation

    Directory of Open Access Journals (Sweden)

    Hsiang-Chun Lee

    2016-01-01

    Full Text Available Metabolic syndrome (MetS represents a cluster of metabolic derangements. Dyslipidemia is an important factor in MetS and is related to atrial fibrillation (AF. We hypothesized that very low density lipoproteins (VLDL in MetS (MetS-VLDL may induce atrial dilatation and vulnerability to AF. VLDL was therefore separated from normal (normal-VLDL and MetS individuals. Wild type C57BL/6 male mice were divided into control, normal-VLDL (nVLDL, and MetS-VLDL (msVLDL groups. VLDL (15 µg/g and equivalent volumes of saline were injected via tail vein three times a week for six consecutive weeks. Cardiac chamber size and function were measured by echocardiography. MetS-VLDL significantly caused left atrial dilation (control, n = 10, 1.64 ± 0.23 mm; nVLDL, n = 7, 1.84 ± 0.13 mm; msVLDL, n = 10, 2.18 ± 0.24 mm; p < 0.0001 at week 6, associated with decreased ejection fraction (control, n = 10, 62.5% ± 7.7%, vs. msVLDL, n = 10, 52.9% ± 9.6%; p < 0.05. Isoproterenol-challenge experiment resulted in AF in young msVLDL mice. Unprovoked AF occurred only in elderly msVLDL mice. Immunohistochemistry showed excess lipid accumulation and apoptosis in msVLDL mice atria. These findings suggest a pivotal role of VLDL in AF pathogenesis for MetS individuals.

  19. Aspartic Acid Racemization and Collagen Degradation Markers Reveal an Accumulation of Damage in Tendon Collagen That Is Enhanced with Aging*

    Science.gov (United States)

    Thorpe, Chavaunne T.; Streeter, Ian; Pinchbeck, Gina L.; Goodship, Allen E.; Clegg, Peter D.; Birch, Helen L.

    2010-01-01

    Little is known about the rate at which protein turnover occurs in living tendon and whether the rate differs between tendons with different physiological roles. In this study, we have quantified the racemization of aspartic acid to calculate the age of the collagenous and non-collagenous components of the high strain injury-prone superficial digital flexor tendon (SDFT) and low strain rarely injured common digital extensor tendon (CDET) in a group of horses with a wide age range. In addition, the turnover of collagen was assessed indirectly by measuring the levels of collagen degradation markers (collagenase-generated neoepitope and cross-linked telopeptide of type I collagen). The fractional increase in d-Asp was similar (p = 0.7) in the SDFT (5.87 × 10−4/year) and CDET (5.82 × 10−4/year) tissue, and d/l-Asp ratios showed a good correlation with pentosidine levels. We calculated a mean (±S.E.) collagen half-life of 197.53 (±18.23) years for the SDFT, which increased significantly with horse age (p = 0.03) and was significantly (p < 0.001) higher than that for the CDET (34.03 (±3.39) years). Using similar calculations, the half-life of non-collagenous protein was 2.18 (±0.41) years in the SDFT and was significantly (p = 0.04) lower than the value of 3.51 (±0.51) years for the CDET. Collagen degradation markers were higher in the CDET and suggested an accumulation of partially degraded collagen within the matrix with aging in the SDFT. We propose that increased susceptibility to injury in older individuals results from an inability to remove partially degraded collagen from the matrix leading to reduced mechanical competence. PMID:20308077

  20. Enhanced accumulation and storage of mercury on subtropical evergreen forest floor: Implications on mercury budget in global forest ecosystems

    Science.gov (United States)

    Wang, Xun; Lin, Che-Jen; Lu, Zhiyun; Zhang, Hui; Zhang, Yiping; Feng, Xinbin

    2016-08-01

    Forest ecosystems play an important role in the global cycling of mercury (Hg). In this study, we characterized the Hg cycling at a remote evergreen broadleaf (EB) forest site in southwest China (Mount Ailao). The annual Hg input via litterfall is estimated to be 75.0 ± 24.2 µg m-2 yr-1 at Mount Ailao. Such a quantity is up to 1 order of magnitude greater than those observed at remote temperate/boreal (T/B) forest sites. Production of litter biomass is found to be the most influential factor causing the high Hg input to the EB forest. Given their large areal coverage, Hg deposition through litterfall in EB forests is appropriately 9 ± 5 Mg yr-1 in China and 1086 ± 775 Mg yr-1 globally. The observed wet Hg deposition at Mount Ailao is 4.9 ± 4.5 µg m-2 yr-1, falling in the lower range of those observed at 49 T/B forest sites in North America and Europe. Given the data, the Hg deposition flux through litterfall is approximately 15 times higher than the wet Hg deposition at Mount Ailao. Steady Hg accumulation in decomposing litter biomass and Hg uptake from the environment were observed during 25 months of litter decomposition. The size of the Hg pool in the organic horizon of EB forest floors is estimated to be up to 2-10 times the typical pool size in T/B forests. This study highlights the importance of EB forest ecosystems in global Hg cycling, which requires further assessment when more data become available in tropical forests.

  1. Arbuscular mycorrhiza increase artemisinin accumulation in Artemisia annua by higher expression of key biosynthesis genes via enhanced jasmonic acid levels.

    Science.gov (United States)

    Mandal, Shantanu; Upadhyay, Shivangi; Wajid, Saima; Ram, Mauji; Jain, Dharam Chand; Singh, Ved Pal; Abdin, Malik Zainul; Kapoor, Rupam

    2015-07-01

    It is becoming increasingly evident that the formation of arbuscular mycorrhiza (AM) enhances secondary metabolite production in shoots. Despite mounting evidence, relatively little is known about the underlying mechanisms. This study suggests that increase in artemisinin concentration in Artemisia annua colonized by Rhizophagus intraradices is due to altered trichome density as well as transcriptional patterns that are mediated via enhanced jasmonic acid (JA) levels. Mycorrhizal (M) plants had higher JA levels in leaf tissue that may be due to induction of an allene oxidase synthase gene (AOS), encoding one of the key enzymes for JA production. Non-mycorrhizal (NM) plants were exogenously supplied with a range of methyl jasmonic acid concentrations. When leaves of NM and M plants with similar levels of endogenous JA were compared, these matched closely in terms of shoot trichome density, artemisinin concentration, and transcript profile of artemisinin biosynthesis genes. Mycorrhization increased artemisinin levels by increasing glandular trichome density and transcriptional activation of artemisinin biosynthesis genes. Transcriptional analysis of some rate-limiting enzymes of mevalonate and methyl erythritol phosphate (MEP) pathways revealed that AM increases isoprenoids by induction of the MEP pathway. A decline in artemisinin concentration in shoots of NM and M plants treated with ibuprofen (an inhibitor of JA biosynthesis) further confirmed the implication of JA in the mechanism of artemisinin production.

  2. Copper-associated hepatitis in dogs; pathogenesis, diagnosis and treatment

    NARCIS (Netherlands)

    Dirksen, K.

    2016-01-01

    Copper is an essential trace element for living organisms, but can have deleterious consequences when present in excess. Because the liver has a central role in copper metabolism, this is the predominant organ affected. Copper-accumulating disorders are recognized as hereditary diseases in man and o

  3. Response of Tribolium castaneum to elevated copper concentrations is influenced by history of metal exposure, sex-specific defences, and infection by the parasite Steinernema feltiae.

    Science.gov (United States)

    Kramarz, Paulina E; Mordarska, Anna; Mroczka, Magdalena

    2014-07-01

    We studied how copper toxicity in the red flour beetle, Tribolium castaneum changed as a result of infection by the entomopathogenic nematode Steinernema feltiae. Measured traits were: respiration, growth and survival, as well as the concentrations of copper within beetle tissues and in its diet. By comparing F1 and F5 generation we were able to answer how long-term metal exposure changed the responses to both copper and the parasite. The beetles did accumulate copper; however, the results indicated that copper concentrations in beetle tissues were affected by nematode infection, the sex of the experimental animals, and the number of generations of exposure. Five generations of exposure to copper resulted in the highest dry body mass of infected beetles of both sexes; additionally, this group also had the lowest copper concentrations in their tissues. The only factor that had a significant effect on respiration was infection by nematodes: infected beetles of both sexes in both generational groups had significantly decreased respiration rates. Survival was lowest in nematode-infected animals of both sexes from both generations, regardless of exposure to copper. Our results confirm that an organism's response to metal pollution is dependent on its health status and sex. We also found that the history of exposure to metal was equally important-we found enhanced resistance to copper intoxication after only five generations of exposure.

  4. Transgenic expression of delta-6 and delta-15 fatty acid desaturases enhances omega-3 polyunsaturated fatty acid accumulation in Synechocystis sp. PCC6803.

    Science.gov (United States)

    Chen, Gao; Qu, Shujie; Wang, Qiang; Bian, Fei; Peng, Zhenying; Zhang, Yan; Ge, Haitao; Yu, Jinhui; Xuan, Ning; Bi, Yuping; He, Qingfang

    2014-03-01

    Polyunsaturated fatty acids (PUFAs), which contain two or more double bonds in their backbone, are the focus of intensive global research, because of their nutritional value, medicinal applications, and potential use as biofuel. However, the ability to produce these economically important compounds is limited, because it is both expensive and technically challenging to separate omega-3 polyunsaturated fatty acids (ω-3 PUFAs) from natural oils. Although the biosynthetic pathways of some plant and microalgal ω-3 PUFAs have been deciphered, current understanding of the correlation between fatty acid desaturase content and fatty acid synthesis in Synechocystis sp. PCC6803 is incomplete. We constructed a series of homologous vectors for the endogenous and exogenous expression of Δ6 and Δ15 fatty acid desaturases under the control of the photosynthesis psbA2 promoter in transgenic Synechocystis sp. PCC6803. We generated six homologous recombinants, harboring various fatty acid desaturase genes from Synechocystis sp. PCC6803, Gibberella fujikuroi and Mortierella alpina. These lines produced up to 8.9 mg/l of α-linolenic acid (ALA) and 4.1 mg/l of stearidonic acid (SDA), which are more than six times the corresponding wild-type levels, at 20°C and 30°C. Thus, transgenic expression of Δ6 and Δ15 fatty acid desaturases enhances the accumulation of specific ω-3 PUFAs in Synechocystis sp. PCC6803. In the blue-green alga Synechocystis sp. PCC6803, overexpression of endogenous and exogenous genes encoding PUFA desaturases markedly increased accumulation of ALA and SDA and decreased accumulation of linoleic acid and γ-linolenic acid. This study lays the foundation for increasing the fatty acid content of cyanobacteria and, ultimately, for producing nutritional and medicinal products with high levels of essential ω-3 PUFAs.

  5. Erythrocyte copper chaperone for superoxide dismutase and superoxide dismutase as biomarkers for hepatic copper concentrations in Labrador retrievers

    NARCIS (Netherlands)

    Dirksen, K; Roelen, Y S; van Wolferen, M E; Kruitwagen, H S; Penning, L C; Burgener, I A; Spee, B; Fieten, H

    2016-01-01

    Hereditary hepatic copper accumulation in Labrador retrievers leads to hepatitis with fibrosis and eventually cirrhosis. The development of a non-invasive blood-based biomarker for copper status in dogs could be helpful in identifying dogs at risk and to monitor copper concentrations during

  6. Copper-induced apical trafficking of ATP7B in polarized hepatoma cells provides a mechanism for biliary copper excretion

    NARCIS (Netherlands)

    Roelofsen, H; Wolters, H; Van Luyn, MJA; Miura, N; Kuipers, F; Vonk, RJ

    2000-01-01

    Background & Aims: Mutations in the ATP7B gene, encoding a copper-transporting P-type adenosine triphosphatase, lead to excessive hepatic copper accumulation because of impaired biliary copper excretion in Wilson's disease. In human liver, ATP7B is predominantly localized to the trans-Golgi network,

  7. Bioindication of air pollution effects near a copper smelter in Brazil using mango trees and soil microbiological properties.

    Science.gov (United States)

    Klumpp, Andreas; Hintemann, Therese; Lima, Josanídia Santana; Kandeler, Ellen

    2003-01-01

    A field study near the copper smelter of a large industrial complex examined air pollution effects on vegetation and soil parameters in Camaçari (northeast Brazil). Close to the smelter, soil pH-value was lower and total acidity as well as organic carbon contents were higher compared with a site far from the source and two reference sites. The acidification of top soil particularly and the drastically enhanced plant-available copper concentrations were caused by atmospheric deposition. High sulphur and copper deposition significantly reduced microbial biomass and altered functional diversity of soil microorganisms (arylsulphatase and xylanase). Large accumulations of sulphur, arsenic and copper were detected in mango leaves (Mangifera indica) growing downwind from the smelter suggesting potential food chain-mediated risk.

  8. Betaine alleviates hepatic lipid accumulation via enhancing hepatic lipid export and fatty acid oxidation in rats fed with a high-fat diet.

    Science.gov (United States)

    Xu, Li; Huang, Danping; Hu, Qiaolin; Wu, Jing; Wang, Yizhen; Feng, Jie

    2015-06-28

    To assess the effects of betaine on hepatic lipid accumulation and investigate the underlying mechanism, thirty-two male Sprague-Dawley rats weighing 100 (sd 2·50) g were divided into four groups, and started on one of four treatments: basal diet, basal diet with betaine administration, high-fat diet and high-fat diet with betaine administration. The results showed that no significant difference of body weight was found among experimental groups. Compared with high-fat diet-fed rats, a betaine supplementation decreased (Pbetaine-homocysteine methyltransferase concentration [corrected] as well as its mRNA abundance and lecithin level were found increased (Pbetaine supplementation in both basal diet-fed rats and high-fat diet-fed rats. Betaine administration in high-fat diet-fed rats exhibited a higher (Pbetaine administration in high-fat diet-fed rats elevated (Pbetaine administration in high-fat diet group; meanwhile the gene expression of hepatic AMP-activated protein kinase was increased (Pbetaine administration enhanced hepatic lipid export and fatty acid oxidation in high-fat diet-fed rats, thus effectively alleviating fat accumulation in the liver.

  9. Soy Leaf Extract Containing Kaempferol Glycosides and Pheophorbides Improves Glucose Homeostasis by Enhancing Pancreatic β-Cell Function and Suppressing Hepatic Lipid Accumulation in db/db Mice.

    Science.gov (United States)

    Li, Hua; Ji, Hyeon-Seon; Kang, Ji-Hyun; Shin, Dong-Ha; Park, Ho-Yong; Choi, Myung-Sook; Lee, Chul-Ho; Lee, In-Kyung; Yun, Bong-Sik; Jeong, Tae-Sook

    2015-08-19

    This study investigated the molecular mechanisms underlying the antidiabetic effect of an ethanol extract of soy leaves (ESL) in db/db mice. Control groups (db/+ and db/db) were fed a normal diet (ND), whereas the db/db-ESL group was fed ND with 1% ESL for 8 weeks. Dietary ESL improved glucose tolerance and lowered plasma glucose, glycated hemoglobin, HOMA-IR, and triglyceride levels. The pancreatic insulin content of the db/db-ESL group was significantly greater than that of the db/db group. ESL supplementation altered pancreatic IRS1, IRS2, Pdx1, Ngn3, Pax4, Ins1, Ins2, and FoxO1 expression. Furthermore, ESL suppressed lipid accumulation and increased glucokinase activity in the liver. ESL primarily contained kaempferol glycosides and pheophorbides. Kaempferol, an aglycone of kaempferol glycosides, improved β-cell proliferation through IRS2-related FoxO1 signaling, whereas pheophorbide a, a product of chlorophyll breakdown, improved insulin secretion and β-cell proliferation through IRS1-related signaling with protein kinase A in MIN6 cells. ESL effectively regulates glucose homeostasis by enhancing IRS-mediated β-cell insulin signaling and suppressing SREBP-1-mediated hepatic lipid accumulation in db/db mice.

  10. Cell wall targeted in planta iron accumulation enhances biomass conversion and seed iron concentration in Arabidopsis and rice

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Haibing [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Wei, Hui [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Ma, Guojie [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Antunes, Mauricio S. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Vogt, Stefan [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; Cox, Joseph [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Zhang, Xiao [Department of Horticulture, Purdue University, West Lafayette IN USA; Liu, Xiping [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Bu, Lintao [National Bioenergy Center, National Renewable Energy Laboratory, Golden CO USA; Gleber, S. Charlotte [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; Carpita, Nicholas C. [Department of Biological Sciences, Purdue University, West Lafayette IN USA; Department of Botany and Plant Pathology, Purdue University, West Lafayette IN USA; Makowski, Lee [Department of Bioengineering, Northeastern University, Boston MA USA; Department of Chemistry and Chemical Biology, Northeastern University, Boston MA USA; Himmel, Michael E. [Biosciences Center, National Renewable Energy Laboratory, Golden CO USA; Tucker, Melvin P. [X-ray Science Division, Advanced Photon Source, Argonne National Laboratory, Argonne IL USA; McCann, Maureen C. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Biological Sciences, Purdue University, West Lafayette IN USA; Murphy, Angus S. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Plant Science and Landscape Architecture, University of Maryland, College Park MD USA; Peer, Wendy A. [Center for Direct Catalytic Conversion Of Biomass to Biofuels (C3Bio), Purdue University, West Lafayette IN USA; Department of Horticulture, Purdue University, West Lafayette IN USA; Department of Plant Science and Landscape Architecture, University of Maryland, College Park MD USA; Department of Environmental Science and Technology, University of Maryland, College Park MD USA

    2016-04-07

    Conversion of nongrain biomass into liquid fuel is a sustainable approach to energy demands as global population increases. Previously, we showed that iron can act as a catalyst to enhance the degradation of lignocellulosic biomass for biofuel production. However, direct addition of iron catalysts to biomass pretreatment is diffusion-limited, would increase the cost and complexity of biorefinery unit operations and may have deleterious environmental impacts. Here, we show a new strategy for in planta accumulation of iron throughout the volume of the cell wall where iron acts as a catalyst in the deconstruction of lignocellulosic biomass. We engineered CBM-IBP fusion polypeptides composed of a carbohydrate-binding module family 11 (CBM11) and an iron-binding peptide (IBP) for secretion into Arabidopsis and rice cell walls. CBM-IBP transformed Arabidopsis and rice plants show significant increases in iron accumulation and biomass conversion compared to respective controls. Further, CBM-IBP rice shows a 35% increase in seed iron concentration and a 40% increase in seed yield in greenhouse experiments. CBM-IBP rice potentially could be used to address iron deficiency, the most common and widespread nutritional disorder according to the World Health Organization.

  11. Prevention of PCDD/Fs emission from a municipal wastewater sludge incinerator through enhanced control of copper aerosol

    Directory of Open Access Journals (Sweden)

    Peña, E.

    2012-10-01

    Full Text Available Municipal wastewater sludge incineration (MWSI leads to products of incomplete combustion, including chlorinated species such as dioxins and furans (PCDD/Fs. Other pollutants, such as heavy metals (HM, are released too as a consequence of feed traces, which depend on the specific activities of each area. The main aim of this work is to determine whether the early separation of the potential catalysts on the PCDD/Fs formation –HM as copper or zinc– offers a promising way to prevent the emission of these trace pollutants, considering that the current end-of-pipe measures don’t ensure their stable emission. Experimental results cover the size distributed target metal contents along the incineration line. These results show a high concentration of copper in the most penetrating aerosol size range of the electrostatic precipitator (0.6 μm - 1.0 μm, and how low emission values of both, total and metallic aerosol (mass basis, are compatible with irregular and unexplained outliers of PCDD/Fs emission.

    La incineración de lodos de aguas residuales urbanas acarrea la formación de compuestos derivados de combustiones incompletas, incluyendo especies cloradas como dioxinas y furanos (PCDD/Fs. Otros contaminantes, como metales pesados, se emiten como consecuencia de las trazas del lodo, las cuales dependen de las actividades del entorno. El objetivo principal es determinar si la separación de catalizadores potenciales en reacciones de formación de PCDD/Fs (cobre o zinc puede abrir vías para prevenir la emisión de contaminantes traza, considerando que ninguna de las técnicas de prevención actuales aseguran emisiones estables de metales pesados o PCDD/Fs. Se determinan concentraciones de metales pesados segregados por tamaño de partícula a lo largo de la línea de incineración. Los resultados muestran concentraciones elevadas de cobre en el aerosol de máxima penetración del electrofiltro (0,6 μm - 1,0 μm, y cómo concentraciones

  12. Effects of matrix types on formation and transformation of energy-accumulating substances in enhanced biological phosphorus removal (EBPR).

    Science.gov (United States)

    Li, D; Fang, Z; Long, X; Tang, R; Di, S

    2016-12-30

    Enhanced biological phosphorus removal (EBPR) has been widely used in wastewater treatment. In this study, a laboratory investigation of activated sludge in A/O-SBR reactor was conducted to probe the effects of the matrix types on EBPR polyphosphate, intracellular polysaccharide, polyhydroxyalkanoates (PHA) formation and transformation. There is a decrease in anaerobic condition and an increase in aerobic condition for the intracellular glycogen of sodium propionate matrix and sodium acetate matrix. While the intracellular glycogen of glucose matrix shows a decreasing tendency in both anaerobic and aerobic reaction process. Sodium acetate matrix is beneficial to the formation of polyhydroxybutyrate (PHB), but the content of PHB is relatively small. PHB and poly-3-hydroxyvalerate (PHV) contents in PHA are quite similar in both anaerobic and aerobic reactions with a PHB/PHV ratio of 0.83-1.45. The synthesis of PHV and PHB is mainly in the initial anaerobic stage (0 h - 1 h). Glucose matrix is helpful to the formation of PHV. The content of polymphosphorus shows an increasing tendency in both anaerobic and aerobic stages, suggesting that glucose matrix acclimation of the reactor favors the formation of polymphosphorus.

  13. Accumulation of free polyamines enhances the antioxidant response in fruits of grafted tomato plants under water stress.

    Science.gov (United States)

    Sánchez-Rodríguez, E; Romero, L; Ruiz, J M

    2016-01-15

    Polyamines, small aliphatic polycations, have been suggested to play key roles in a number of biological processes. In this paper, attempts were made to investigate the possibility of improving antioxidant response of tomato fruits in relation with endogenous free polyamines content. We studied the reactive oxygen species and polyamines content, and antioxidant and polyamine-biosynthesis enzyme activities in fruits of ungrafted and grafted tomato plants under moderate water stress. We used a drought-tolerant cultivar (Zarina) and drought-sensitive cultivar (Josefina) to obtain reciprocal graft, selfgraft and ungraft plants. Fruits contained higher endogenous polyamine content during the course of the experiment relative to the control, coupled with higher arginine decarboxylase and spermine synthase activities in Zarina ungrafted and ZarxJos. In these cultivars, tomato fruits showed a lower reactive oxygen species generation and higher catalase and superoxide dismutase activities, suggesting that a higher content in polyamines (especially spermine) exerted a positive effect on antioxidant systems. All of these data suggest that spermine leads to more effective reactive oxygen species scavenging (less tissue damage) in tomato fruits, which may function collectively to enhance dehydration tolerance.

  14. Accumulation of eicosapolyenoic acids enhances sensitivity to abscisic acid and mitigates the effects of drought in transgenic Arabidopsis thaliana.

    Science.gov (United States)

    Yuan, Xiaowei; Li, Yaxiao; Liu, Shiyang; Xia, Fei; Li, Xinzheng; Qi, Baoxiu

    2014-04-01

    IgASE1, a C₁₈ Δ(9)-specific polyunsaturated fatty acid elongase from the marine microalga Isochrysis galbana, is able to convert linoleic acid and α-linolenic acid to eicosadienoic acid and eicosatrienoic acid in Arabidopsis. Eicosadienoic acid and eicosatrienoic acid are precursors of arachidonic acid, eicosapentaenoic acid, and docosahexaenoic acid, which are synthesized via the Δ(8) desaturation biosynthetic pathways. This study shows that the IgASE1-expressing transgenic Arabidopsis exhibited altered morphology (decreased leaf area and biomass) and enhanced drought resistance compared to wild-type plants. The transgenic Arabidopsis were hypersensitive to abscisic acid (ABA) during seed germination, post-germination growth, and seedling development. They had elevated leaf ABA levels under well-watered and dehydrated conditions and their stomata were more sensitive to ABA. Exogenous application of eicosadienoic acid and eicosatrienoic acid can mimic ABA and drought responses in the wild type plants, similar to that found in the transgenic ones. The transcript levels of genes involved in the biosynthesis of ABA (NCED3, ABA1, AAO3) as well as other stress-related genes were upregulated in this transgenic line upon osmotic stress (300 mM mannitol). Taken together, these results indicate that these two eicosapolyenoic acids or their derived metabolites can mitigate the effects of drought in transgenic Arabidopsis, at least in part, through the action of ABA.

  15. Redox cycling of a copper complex with benzaldehyde nitrogen mustard-2-pyridine carboxylic acid hydrazone contributes to its enhanced antitumor activity, but no change in the mechanism of action occurs after chelation.

    Science.gov (United States)

    Yang, Yinli; Li, Cuiping; Fu, Yun; Liu, Youxun; Zhang, Yu; Zhang, Yanfang; Zhou, Pingxin; Yuan, Yanbin; Zhou, Sufeng; Li, Shaoshan; Li, Changzheng

    2016-03-01

    Many anticancer drugs used in the clinical have potent metal chelating ability. The formed metal complex(es) may exhibit improved (or antagonistic) antitumor activity. However, the underlying mechanism has received limited attention. Therefore, investigation of the mechanism involved in the change upon chelation is required to extend our understanding of the effects of various drugs. In the present study, the proliferation inhibition effect of benzaldehyde nitrogen mustard-2-pyridine carboxylic acid hydrazone (BNMPH) and its copper complex on tumor cell lines was investigated. The copper chelate exhibited almost a 10-fold increase in antitumor activity (with IC50 copper complex induced reactive oxygen species (ROS) generation, and caused upregulation of caspase 8 and Bax as well as the downregulation of Bcl-2, indicating that apoptosis was involved in the cytotoxic effects. DNA fragmentation noted in the comet assay further supported ROS involvement. The present study indicated that BNMPH and its copper complex effectively induced S phase arrest and the cell cycle arrest was associated with the downregulation of cyclin D1. The formation of acidic vesicular organelles (AVOs) and an increase in cleaved LC3-II demonstrated that autophagy occurred in the HepG2 cells treated with the agents. Taken together, BNMPH and its copper complex exhibited proliferation inhibition via apoptosis, cell cycle arrest and autophagy, which was dependent on ROS. The enhanced antitumor activity of the copper complex was due to its redox-cycling ability, but the mechanism was not altered compared to BNMPH. Our findings may significantly contribute to the understanding of the anti-proliferative effect of BNMPH and its copper complex.

  16. Copper resistance in Pseudomonas syringae mediated by periplasmic and outer membrane proteins.

    OpenAIRE

    Cha, J S; Cooksey, D A

    1991-01-01

    Copper-resistant strains of Pseudomonas syringae pathovar tomato accumulate copper and develop blue colonies on copper-containing media. Three of the protein products of the copper-resistance operon (cop) were characterized to provide an understanding of the copper-resistance mechanism and its relationship to copper accumulation. The Cop proteins, CopA (72 kDa), CopB (39 kDa), and CopC (12 kDa), were produced only under copper induction. CopA and CopC were periplasmic proteins and CopB was an...

  17. Miscellaneous additives can enhance plant uptake and affect geochemical fractions of copper in a heavily polluted riparian grassland soil.

    Science.gov (United States)

    Rinklebe, Jörg; Shaheen, Sabry M

    2015-09-01

    The problem of copper (Cu) pollution in riverine ecosystems is world-wide and has significant environmental, eco-toxicological, and agricultural relevance. We assessed the suitability and effectiveness of application rate of 1% of activated charcoal, bentonite, biochar, cement kiln dust, chitosan, coal fly ash, limestone, nano-hydroxyapatite, organo-clay, sugar beet factory lime, and zeolite as soil amendments together with rapeseed as bioenergy crop as a possible remediation option for a heavily Cu polluted floodplain soil (total Cu=3041.9mgkg(-1)) that has a very high proportion of sorbed/carbonate fraction (484.6mgkg(-1)) and potential mobile fraction of Cu (1611.9mgkg(-1)). Application changed distribution of Cu among geochemical fractions: alkaline materials lead to increased carbonate bounded fraction and the acid rhizosphere zone might cause release of this Cu. Thus, mobilization of Cu and uptake of Cu by rapeseed were increased compared to the control (except for organo-clay) under the prevailing conditions.

  18. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg–Cu–Y metallic glass powder through dealloying pretreatment

    Energy Technology Data Exchange (ETDEWEB)

    Luo, Xuekun; Li, Ran, E-mail: liran@buaa.edu.cn; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao, E-mail: zhangtao@buaa.edu.cn

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg{sub 65}Cu{sub 25}Y{sub 10} metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core–shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  19. Enhanced degradation of azo dye by nanoporous-copper-decorated Mg-Cu-Y metallic glass powder through dealloying pretreatment

    Science.gov (United States)

    Luo, Xuekun; Li, Ran; Zong, Jingzhen; Zhang, Ying; Li, Haifei; Zhang, Tao

    2014-06-01

    A controllable uniform nanoporous copper (NPC) layer was synthesized on the surface of the ball-milled powder of Mg65Cu25Y10 metallic glass by dealloying. The morphology, the elemental surface composition and the phase structure of the powders were characterized by scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray diffractometry, respectively. The composite powder with a core-shell structure shows higher degradation efficiency of the azo dye of Direct Blue 6 than the untreated powder and the pure NPC. The improved performance can be attributed to the strong synergistic effect between the NPC layer and the metallic glass matrix, because the nanoporous structure provides large surface area for the adsorption of the dye molecules and three-dimensional diffusion channels of reaction masses, as well as the dissolution acceleration of the active atoms through local galvanic cell reaction. This tunable pretreatment is a promising surface activation method for novel chemical applications of metallic glasses.

  20. Jinlida granule inhibits palmitic acid induced-intracellular lipid accumulation and enhances autophagy in NIT-1 pancreatic β cells through AMPK activation.

    Science.gov (United States)

    Wang, Dingkun; Tian, Min; Qi, Yuan; Chen, Guang; Xu, Lijun; Zou, Xin; Wang, Kaifu; Dong, Hui; Lu, Fuer

    2015-02-23

    TOR and the up-regulation of TSC1 and LC3-II proteins expression. However, when AMPK phosphorylation was inhibited by Compound C, JLDG supplementation did not exhibit any effect on the expression of these AMPK downstream molecules in NIT-1 cells. The results suggest that JLDG could reduce intracellular lipid accumulation and enhance the autophagy in NIT-1 pancreatic β cells cultured with PA. The mechanism is possibly mediated by AMPK activation. Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.

  1. Copper-associated hepatitis in the Labrador retriever : diagnosis, treatment and genetics

    NARCIS (Netherlands)

    Fieten, H.

    2015-01-01

    Copper is an essential trace element and is indispensable for a large number of important biological processes in the body. The liver is important for copper metabolism and is the first organ to be affected in copper overload. Hepatic copper accumulation results from excessive intake and/or from inh

  2. Enhancement of photodetection characteristics of MoS2 field effect transistors using surface treatment with copper phthalocyanine

    Science.gov (United States)

    Pak, Jinsu; Jang, Jingon; Cho, Kyungjune; Kim, Tae-Young; Kim, Jae-Keun; Song, Younggul; Hong, Woong-Ki; Min, Misook; Lee, Hyoyoung; Lee, Takhee

    2015-11-01

    Recently, two-dimensional materials such as molybdenum disulfide (MoS2) have been extensively studied as channel materials for field effect transistors (FETs) because MoS2 has outstanding electrical properties such as a low subthreshold swing value, a high on/off ratio, and good carrier mobility. In this study, we characterized the electrical and photo-responsive properties of MoS2 FET when stacking a p-type organic copper phthalocyanine (CuPc) layer on the MoS2 surface. We observed that the threshold voltage of MoS2 FET could be controlled by stacking the CuPc layers due to a charge transfer phenomenon at the interface. Particularly, we demonstrated that CuPc/MoS2 hybrid devices exhibited high performance as a photodetector compared with the pristine MoS2 FETs, caused by more electron-hole pairs separation at the p-n interface. Furthermore, we found the optimized CuPc thickness (~2 nm) on the MoS2 surface for the best performance as a photodetector with a photoresponsivity of ~1.98 A W-1, a detectivity of ~6.11 × 1010 Jones, and an external quantum efficiency of ~12.57%. Our study suggests that the MoS2 vertical hybrid structure with organic material can be promising as efficient photodetecting devices and optoelectronic circuits.Recently, two-dimensional materials such as molybdenum disulfide (MoS2) have been extensively studied as channel materials for field effect transistors (FETs) because MoS2 has outstanding electrical properties such as a low subthreshold swing value, a high on/off ratio, and good carrier mobility. In this study, we characterized the electrical and photo-responsive properties of MoS2 FET when stacking a p-type organic copper phthalocyanine (CuPc) layer on the MoS2 surface. We observed that the threshold voltage of MoS2 FET could be controlled by stacking the CuPc layers due to a charge transfer phenomenon at the interface. Particularly, we demonstrated that CuPc/MoS2 hybrid devices exhibited high performance as a photodetector compared

  3. Tetra-methyl substituted copper (II phthalocyanine as a hole injection enhancer in organic light-emitting diodes

    Directory of Open Access Journals (Sweden)

    Yu-Long Wang

    2015-10-01

    Full Text Available We have enhanced hole injection and lifetime in organic light-emitting diodes (OLEDs by incorporating the isomeric metal phthalocyanine, CuMePc, as a hole injection enhancer. The OLED devices containing CuMePc as a hole injection layer (HIL exhibited higher luminous efficiency and operational lifetime than those using a CuPc layer and without a HIL. The effect of CuMePc thickness on device performance was investigated. Atomic force microscope (AFM studies revealed that the thin films were smooth and uniform because the mixture of CuMePc isomers depressed crystallization within the layer. This may have caused the observed enhanced hole injection, indicating that CuMePc is a promising HIL material for highly efficient OLEDs.

  4. Tetra-methyl substituted copper (II) phthalocyanine as a hole injection enhancer in organic light-emitting diodes

    Science.gov (United States)

    Wang, Yu-Long; Xu, Jia-Ju; Lin, Yi-Wei; Chen, Qian; Shan, Hai-Quan; Yan, Yan; Roy, V. A. L.; Xu, Zong-Xiang

    2015-10-01

    We have enhanced hole injection and lifetime in organic light-emitting diodes (OLEDs) by incorporating the isomeric metal phthalocyanine, CuMePc, as a hole injection enhancer. The OLED devices containing CuMePc as a hole injection layer (HIL) exhibited higher luminous efficiency and operational lifetime than those using a CuPc layer and without a HIL. The effect of CuMePc thickness on device performance was investigated. Atomic force microscope (AFM) studies revealed that the thin films were smooth and uniform because the mixture of CuMePc isomers depressed crystallization within the layer. This may have caused the observed enhanced hole injection, indicating that CuMePc is a promising HIL material for highly efficient OLEDs.

  5. Tetra-methyl substituted copper (II) phthalocyanine as a hole injection enhancer in organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yu-Long; Xu, Jia-Ju; Lin, Yi-Wei; Chen, Qian; Shan, Hai-Quan; Xu, Zong-Xiang, E-mail: xu.zx@sustc.edu.cn, E-mail: val.roy@cityu.edu.hk [Department of Chemistry, South University of Science and Technology of China, Shenzhen, Guangdong, P. R. China, 518055 (China); Yan, Yan; Roy, V. A. L., E-mail: xu.zx@sustc.edu.cn, E-mail: val.roy@cityu.edu.hk [Department of Physics and Materials Science, City University of Hong Kong, Hong Kong SAR (Hong Kong)

    2015-10-15

    We have enhanced hole injection and lifetime in organic light-emitting diodes (OLEDs) by incorporating the isomeric metal phthalocyanine, CuMePc, as a hole injection enhancer. The OLED devices containing CuMePc as a hole injection layer (HIL) exhibited higher luminous efficiency and operational lifetime than those using a CuPc layer and without a HIL. The effect of CuMePc thickness on device performance was investigated. Atomic force microscope (AFM) studies revealed that the thin films were smooth and uniform because the mixture of CuMePc isomers depressed crystallization within the layer. This may have caused the observed enhanced hole injection, indicating that CuMePc is a promising HIL material for highly efficient OLEDs.

  6. Enhanced ethanol sensing characteristics of In2O3-decorated NiO hollow nanostructures via modulation of hole accumulation layers.

    Science.gov (United States)

    Kim, Hyo-Joong; Jeong, Hyun-Mook; Kim, Tae-Hyung; Chung, Jae-Ho; Kang, Yun Chan; Lee, Jong-Heun

    2014-10-22

    In this work, we report a dramatic enhancement in ethanol sensing characteristics of NiO hollow nanostructures via decoration with In2O3 nanoclusters. The pure NiO and 1.64-4.41 atom % In-doped NiO and In2O3-decorated NiO hollow spheres were prepared by ultrasonic spray pyrolysis, and their gas sensing characteristics were investigated. The response (the ratio between the resistance in gas and air) of the In2O3-decorated NiO hollow spheres to 5 ppm ethanol (C2H5OH) was 9.76 at 350 °C, which represents a significant improvement over the In-doped NiO and pure NiO hollow spheres (3.37 and 2.18, respectively). Furthermore, the 90% recovery time was drastically reduced from 1880 to 23 s, and a selective detection of ethanol with negligible cross-response to other gases was achieved. The enhanced gas response and fast recovery kinetics were explained in relation to the thinning of the near-surface hole accumulation layer of p-type NiO underneath n-type In2O3, the change of charge carrier concentration, and the variation of oxygen adsorption.

  7. Overexpression of an alfalfa GDP-mannose 3, 5-epimerase gene enhances acid, drought and salt tolerance in transgenic Arabidopsis by increasing ascorbate accumulation.

    Science.gov (United States)

    Ma, Lichao; Wang, Yanrong; Liu, Wenxian; Liu, Zhipeng

    2014-11-01

    GDP-mannose 3', 5'-epimerase (GME) catalyses the conversion of GDP-D-mannose to GDP-L-galactose, an important step in the ascorbic acid (ascorbic acid) biosynthetic pathway in higher plants. In this study, a novel cDNA fragment (MsGME) encoding a GME protein was isolated and characterised from alfalfa (Medicago sativa). An expression analysis confirmed that MsGME expression was induced by salinity, PEG and acidity stresses. MsGME overexpression in Arabidopsis enhanced tolerance of the transgenic plants to salt, drought and acid. Real-time PCR analysis revealed that the transcript levels of GDP-D-mannose pyrophosphorylase (GMP), L-galactose-phosphate 1-P phosphatase (GP) and GDP-L-galactose phosphorylase (GGP) were increased in transgenic Arabidopsis (T3 generation). Moreover, the ascorbate content was increased in transgenic Arabidopsis. Our results suggest that MsGME can effectively enhance tolerance of transgenic Arabidopsis to acid, drought and salt by increasing ascorbate accumulation.

  8. Epibrassinolide induces changes in indole-3-acetic acid, abscisic acid and polyamine concentrations and enhances antioxidant potential of radish seedlings under copper stress.

    Science.gov (United States)

    Choudhary, Sikander Pal; Bhardwaj, Renu; Gupta, Bishan Datt; Dutt, Prabhu; Gupta, Rajinder Kumar; Biondi, Stefania; Kanwar, Mukesh

    2010-11-01

    In the present study, the effects of epibrassinolide (EBL) on indole-3-acetic acid (IAA), abscisic acid (ABA) and polyamine (PA) tissue concentrations and antioxidant potential of 7-day-old Raphanus sativus L. cv. 'Pusa chetki' seedlings grown under Cu stress were investigated. EBL treatment alone or in combination with Cu enhanced free and bound IAA titers when compared with the metal alone. Modest increases in free and bound ABA contents were observed for EBL treatment alone. However, the combination of EBL with Cu caused major increases in both forms of ABA, over Cu alone. Among the PAs analyzed, only putrescine and cadaverine concentrations were enhanced by EBL treatment alone. By contrast, a significant decline in putrescine and spermine contents was found in seedlings treated with EBL plus Cu. EBL treatments alone or in combination with Cu enhanced activities of guaiacol peroxidase (EC1.11.1.7), catalase (EC 1.11.1.6), superoxide dismutase (EC 1.15.1.1) and glutathione reductase (EC 1.6.4.2) and protein contents in comparison with metal and control treatments. A major decrease in malondialdehyde content was also recorded for EBL treatments with or without Cu. An increase in phytochelatin content was also observed in seedlings treated with EBL alone or in combination with Cu. Major improvement in radical scavenging activities, as attested by the antioxidant activity assay using DPPH (1,1-diphenylpicrylhydrazyl), and elevated deoxyribose and reducing powers, along with increased contents of ascorbic acid, total phenols and proline, also suggest a major influence of EBL application in mitigating copper-induced oxidative stress in radish seedlings. Copyright © Physiologia Plantarum 2010.

  9. Enhanced Oxidative Stress and Physiological Damage in Daphnia magna by Copper in the Presence of Nano-TiO2

    Directory of Open Access Journals (Sweden)

    W. H. Fan

    2012-01-01

    Full Text Available This study examines the potential hazard of an individual nanomaterial on the Cu biotoxicity to aquatic organisms. Daphnia magna in the absence or presence of nano-TiO2 was exposed to Cu. Maintaining nano-TiO2 at a safe concentration cannot eliminate its potential hazard. The biomarkers superoxide dismutase, catalase, and Na+/K+-ATPase in D. magna were measured. Cu in the presence of nano-TiO2 induced higher levels of oxidative stress and physiological damage because of the sorption of Cu. Nano-TiO2 also caused Na+/K+-ATPase inhibition possibly by impeding the Na+/K+ transfer channel. The correlations among the biomarkers, mortality, and accumulation further showed that the overloading reactive oxygen species generation caused by nano-TiO2 contributed to deeper oxidative stress and physiological regulation, thereby causing greater toxic injury.

  10. Purple Tea and Its Extract Suppress Diet-induced Fat Accumulation in Mice and Human Subjects by Inhibiting Fat Absorption and Enhancing Hepatic Carnitine Palmitoyltransferase Expression.

    Science.gov (United States)

    Shimoda, Hiroshi; Hitoe, Shoketsu; Nakamura, Seikou; Matsuda, Hisashi

    2015-06-01

    A number of clinical trials have been completed using green tea and black tea to investigate their effect in controlling weight in overweight adults. The results of these investigations, however, have often been contradictory, with some trials reporting positive effects of tea supplementation and some trials reporting no effect. As a result, the use of these teas for weight loss is controversial. Purple tea is a variety of green tea developed in Kenya (called TRFK306), which in addition to certain tea constituents found in green tea, also contains anthocyanins. The major constituents in the leaves of purple tea are caffeine, theobromine, epigallocatechin (ECG), epigallocatechin gallate (EGCG) and 1,2-di-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-β-D-glucose (GHG). We investigated the efficacy of purple tea extract (PTE) on diet-induced fat accumulation in mice. PTE administration (200 mg/kg) significantly suppressed body weight gain, liver weight, abdominal fat and triglycerides in serum and liver. Protein expression of carnitine palmitoyltransferase (CPT) 1A was also enhanced. In olive oil loaded mice, PTE (100 mg/kg) and caffeine (25 mg/kg) suppressed fat absorption. PTE (10 μg/mL) and GHG (10 μg/mL) also enhanced protein expression of CPT1A in HepG2 hepatoma. Moreover, 4-week daily consumption of purple tea drink in humans improved obesity parameters compared to baseline, including body weight (79.9 ± 3.1 kg vs 80.8 ± 3.2, pweight gain by suppression of fat absorption and enhancement of hepatic fat metabolism.

  11. Enhanced cadmium accumulation and tolerance in transgenic tobacco overexpressing rice metal tolerance protein gene OsMTP1 is promising for phytoremediation.

    Science.gov (United States)

    Das, Natasha; Bhattacharya, Surajit; Maiti, Mrinal K

    2016-08-01

    One of the most grievous heavy metal pollutants in the environment is cadmium (Cd), which is not only responsible for the crop yield loss owing to its phytotoxicity, but also for the human health hazards as the toxic elements usually accumulate in the consumable parts of crop plants. In the present study, we aimed to isolate and functionally characterize the OsMTP1 gene from indica rice (Oryza sativa L. cv. IR64) to study its potential application for efficient phytoremediation of Cd. The 1257 bp coding DNA sequence (CDS) of OsMTP1 encodes a ∼46 kDa protein belonging to the cation diffusion facilitator (CDF) or metal tolerance/transport protein (MTP) family. The OsMTP1 transcript in rice plant was found to respond during external Cd stress. Heterologous expression of OsMTP1 in tobacco resulted in the reduction of Cd stress-induced phytotoxic effects, including growth inhibition, lipid peroxidation, and cell death. Compared to untransformed control, the transgenic tobacco plants showed enhanced vacuolar thiol content, indicating vacuolar localization of the sequestered Cd. The transgenic tobacco plants exhibited significantly higher biomass growth (2.2-2.8-folds) and hyperaccumulation of Cd (1.96-2.22-folds) compared to untransformed control under Cd exposure. The transgenic plants also showed moderate tolerance and accumulation of arsenic (As) upon exogenous As stress, signifying broad substrate specificity of OsMTP1. Together, findings of our research suggest that the transgenic tobacco plants overexpressing OsMTP1 with its hyperaccumulating activity and increased growth rate could be useful for future phytoremediation applications to clean up the Cd-contaminated soil. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

  12. Chromoplast-specific carotenoid-associated protein appears to be important for enhanced accumulation of carotenoids in hp1 tomato fruits.

    Science.gov (United States)

    Kilambi, Himabindu Vasuki; Kumar, Rakesh; Sharma, Rameshwar; Sreelakshmi, Yellamaraju

    2013-04-01

    Tomato (Solanum lycopersicum) high-pigment mutants with lesions in diverse loci such as DNA Damage-Binding Protein1 (high pigment1 [hp1]), Deetiolated1 (hp2), Zeaxanthin Epoxidase (hp3), and Intense pigment (Ip; gene product unknown) exhibit increased accumulation of fruit carotenoids coupled with an increase in chloroplast number and size. However, little is known about the underlying mechanisms exaggerating the carotenoid accumulation and the chloroplast number in these mutants. A comparison of proteome profiles from the outer pericarp of hp1 mutant and wild-type (cv Ailsa Craig) fruits at different developmental stages revealed at least 72 differentially expressed proteins during ripening. Hierarchical clustering grouped these proteins into three clusters. We found an increased abundance of chromoplast-specific carotenoid-associated protein (CHRC) in hp1 fruits at red-ripe stage that is also reflected in its transcript level. Western blotting using CHRC polyclonal antibody from bell pepper (Capsicum annuum) revealed a 2-fold increase in the abundance of CHRC protein in the red-ripe stage of hp1 fruits compared with the wild type. CHRC levels in hp2 were found to be similar to that of hp1, whereas hp3 and Ip showed intermediate levels to those in hp1, hp2, and wild-type fruits. Both CHRC and carotenoids were present in the isolated plastoglobules. Overall, our results suggest that loss of function of DDB1, DET1, Zeaxanthin Epoxidase, and Ip up-regulates CHRC levels. Increase in CHRC levels may contribute to the enhanced carotenoid content in these high-pigment fruits by assisting in the sequestration and stabilization of carotenoids.

  13. Targeted deletion of the ara operon of Salmonella typhimurium enhances L-arabinose accumulation and drives PBAD-promoted expression of anti-cancer toxins and imaging agents.

    Science.gov (United States)

    Hong, Hyun; Lim, Daejin; Kim, Geun-Joong; Park, Seung-Hwan; Sik Kim, Hyeon; Hong, Yeongjin; Choy, Hyon E; Min, Jung-Joon

    2014-01-01

    Tumor-specific expression of antitumor drugs can be achieved using attenuated Salmonella typhimurium harboring the PBAD promoter, which is induced by L-arabinose. However, L-arabinose does not accumulate because it is metabolized to D-xylulose-5-P by enzymes encoded by the ara operon in Salmonellae. To address this problem, we developed an engineered strain of S. typhimurium in which the ara operon is deleted. Linear DNA transformation was performed using λ red recombinase to exchange the ara operon with linear DNA carrying an antibiotic-resistance gene with homology to regions adjacent to the ara operon. The ara operon-deleted strain and its parental strain were transformed with a plasmid encoding Renilla luciferase variant 8 (RLuc8) or cytolysin A (clyA) under the control of the PBAD promoter. Luciferase assays demonstrated that RLuc8 expression was 49-fold higher in the ara operon-deleted S. typhimurium than in the parental strain after the addition of L-arabinose. In vivo bioluminescence imaging showed that the tumor tissue targeted by the ara operon-deleted Salmonella had a stronger imaging signal (~30-fold) than that targeted by the parental strain. Mice with murine colon cancer (CT26) that had been injected with the ara operon-deleted S. typhimurium expressing clyA showed significant tumor suppression. The present report demonstrates that deletion of the ara operon of S. typhimurium enhances L-arabinose accumulation and thereby drives PBAD-promoted expression of cytotoxic agents and imaging agents. This is a promising approach for tumor therapy and imaging.

  14. Engineered Cyanophycin Synthetase (CphA) from Nostoc ellipsosporum Confers Enhanced CphA Activity and Cyanophycin Accumulation to Escherichia coli▿

    Science.gov (United States)

    Hai, Tran; Frey, Kay M.; Steinbüchel, Alexander

    2006-01-01

    The cyanophycin (CGP) synthetase gene (cphANE1) of the transposon-induced argL mutant NE1 of the cyanobacterium Nostoc ellipsosporum, which exhibits a CGP-leaky phenotype during diazotrophical growth, was cloned and expressed in Escherichia coli strain TOP10. Its amino acid sequence exhibited high similarities to CphAs of other cyanobacteria. Recombinant cells of E. coli, which harbored a fragment comprising the complete cphANE1 gene plus 400 bp of its downstream region in colinear orientation to the lacZ promoter, accumulated CGP up to 17 and 8.5% (wt/wt) of cellular dry matter (CDM) if cultivated in complex medium in the presence or absence of isopropyl-β-d-thiogalactopyranoside, respectively. Two truncated CphAs, lacking 31 (CphANE1del96) or 59 (CphANE1del180) amino acids of the C-terminal region, were derived from cphANE1 by deleting 96 or 180 bp from its 3′ region through the introduction of stop codons. In comparison to the wild-type gene, cphANE1del96 conferred about 2.1- to 2.2-fold-higher enzyme activity (up to 5.75 U/mg protein) on E. coli. Furthermore, these cells accumulated about twofold more CGP (up to 34.5% [wt/wt] of CDM) than cells expressing the wild-type gene. An engineered CphA possessing significantly enhanced activity and conferring the highest CGP content on E. coli is demonstrated. In contrast, CphANE1del180 was inactive and did not confer CGP accumulation on E. coli. Interestingly, a short conserved stretch of 4 to 5 hydrophobic amino acids is located in the protein region present in CphANE1del96 but absent in CphANE1del180. In addition, CphANE1 and CphANE1del96 are, besides CphA from Acinetobacter baylyi, the only CphAs exhibiting rigid substrate specificities that do not enable the incorporation of lysine instead of arginine into CGP. PMID:17012590

  15. Copper Enhanced Monooxygenase Activity and FT-IR Spectroscopic Characterisation of Biotransformation Products in Trichloroethylene Degrading Bacterium: Stenotrophomonas maltophilia PM102

    Directory of Open Access Journals (Sweden)

    Piyali Mukherjee

    2013-01-01

    Full Text Available Stenotrophomonas maltophilia PM102 (NCBI GenBank Acc. no. JQ797560 is capable of growth on trichloroethylene as the sole carbon source. In this paper, we report the purification and characterisation of oxygenase present in the PM102 isolate. Enzyme activity was found to be induced 10.3-fold in presence of 0.7 mM copper with a further increment to 14.96-fold in presence of 0.05 mM NADH. Optimum temperature for oxygenase activity was recorded at 36∘C. The reported enzyme was found to have enhanced activity at pH 5 and pH 8, indicating presence of two isoforms. Maximum activity was seen on incubation with benzene compared to other substrates like TCE, chloroform, toluene, hexane, and petroleum benzene. Km and Vmax for benzene were 3.8 mM and 340 U/mg/min and those for TCE were 2.1 mM and 170 U/mg/min. The crude enzyme was partially purified by ammonium sulphate precipitation followed by dialysis. Zymogram analysis revealed two isoforms in the 70% purified enzyme fraction. The activity stain was more prominent when the native gel was incubated in benzene as substrate in comparison to TCE. Crude enzyme and purified enzyme fractions were assayed for TCE degradation by the Fujiwara test. TCE biotransformation products were analysed by FT-IR spectroscopy.

  16. Piezo-phototronic effect enhanced UV photodetector based on CuI/ZnO double-shell grown on flexible copper microwire

    Science.gov (United States)

    Liu, Jingyu; Zhang, Yang; Liu, Caihong; Peng, Mingzeng; Yu, Aifang; Kou, Jinzong; Liu, Wei; Zhai, Junyi; Liu, Juan

    2016-06-01

    In this work, we present a facile, low-cost, and effective approach to fabricate the UV photodetector with a CuI/ZnO double-shell nanostructure which was grown on common copper microwire. The enhanced performances of Cu/CuI/ZnO core/double-shell microwire photodetector resulted from the formation of heterojunction. Benefiting from the piezo-phototronic effect, the presentation of piezocharges can lower the barrier height and facilitate the charge transport across heterojunction. The photosensing abilities of the Cu/CuI/ZnO core/double-shell microwire detector are investigated under different UV light densities and strain conditions. We demonstrate the I- V characteristic of the as-prepared core/double-shell device; it is quite sensitive to applied strain, which indicates that the piezo-phototronic effect plays an essential role in facilitating charge carrier transport across the CuI/ZnO heterojunction, then the performance of the device is further boosted under external strain.

  17. Hierarchical nanostructures of copper(II) phthalocyanine on electrospun TiO(2) nanofibers: controllable solvothermal-fabrication and enhanced visible photocatalytic properties.

    Science.gov (United States)

    Zhang, Mingyi; Shao, Changlu; Guo, Zengcai; Zhang, Zhenyi; Mu, Jingbo; Cao, Tieping; Liu, Yichun

    2011-02-01

    In the present work, 2,9,16,23-tetranitrophthalocyanine copper(II) (TNCuPc)/TiO(2) hierarchical nanostructures were successfully fabricated by a simple combination method of electrospinning technique and solvothermal processing. Scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD), UV-vis diffuse reflectance (DR), Fourier transform infrared spectrum (FT-IR), X-ray photoelectron spectroscopy (XPS), and thermal gravimetric and differential thermal analysis (TG-DTA) were used to characterize the as-synthesized TNCuPc/TiO(2) hierarchical nanostructures. The results showed that the secondary TNCuPc nanostructures were not only successfully grown on the primary TiO(2) nanofibers substrates but also uniformly distributed without aggregation. By adjusting the solvothermal fabrication parameters, the TNCuPc nanowires or nanoflowers were facilely fabricated, and also the loading amounts of TNCuPc could be controlled on the TNCuPc/TiO(2) hierarchical nanostructural nanofibers. And, there might exist the interaction between TNCuPc and TiO(2). A possible mechanism for the formation of TNCuPc/TiO(2) hierarchical nanostructures was suggested. The photocatalytic studies revealed that the TNCuPc/TiO(2) hierarchical nanostructures exhibited enhanced photocatalytic efficiency of photodegradation of Rhodamine B (RB) compared with the pure TNCuPc or TiO(2) nanofibers under visible-light irradiation.

  18. Surface enhanced Raman scattering, electronic spectrum, natural bond orbital, and Mulliken charge distribution in the normal modes of diethyldithiocarbamate copper (II) complex, [Cu(DDTC)2].

    Science.gov (United States)

    Téllez Soto, C A; Costa, A C; Ramos, J M; Vieira, L S; Rost, N C V; Versiane, O; Rangel, J L; Mondragón, M A; Raniero, L; Martin, A A

    2013-12-01

    Surface-enhanced Raman scattering (SERS) was used to study the interactions of the normal modes of the diethyldithiocarbamate copper (II) complex, [Cu(DDTC)2] on nano-structured mixture silver-gold surfaces and on silver surfaces. The electronic spectrum of this complex was measured and the charge transfer bands were assigned through the TD-PBE1PBE procedure. Natural bond orbital (NBO) were also carried out to study the Cu(II) hybridation leading to the square planar geometry of the framework of the [Cu(DDTC)2] complex, and to study which are the donor NBO and the acceptor NBO in meaningful charge transfer through the Second Order Perturbation Theory Analysis of the Fox Matrix in NBO basis. To see the electronic dispersion, the Mulliken electronic charges (MAC) were calculated for each normal mode and correlated with the SERS effect. Full assignment of the SERS spectra was also supported by carefully analysis of the distorted geometries generated by the normal modes.

  19. Enhancement of performance of AlGaN/GaN high-electron-mobility transistors by transfer from sapphire to a copper plate

    Science.gov (United States)

    Hiroki, Masanobu; Kumakura, Kazuhide; Yamamoto, Hideki

    2016-05-01

    We transferred AlGaN/GaN high-electron-mobility transistors (HEMTs) from a sapphire substrate to a copper plate using the hexagonal boron nitride epitaxial lift-off technique. After transfer, the negative slope in the drain current I d decreased owing to the suppression of the self-heating effect. The significant increase in I d and the negative shift of threshold voltage indicate an increase in two-dimensional electron gas (2DEG) density. The increase in 2DEG density is at least partially caused by the reduction in compressive stress in the GaN layer after the transfer, which is revealed from the E 2 peak shifts of -1.3 cm-1 in Raman spectroscopy measurements. We also estimated the temperature in the active region of HEMTs by micro-Raman spectroscopy. For the transferred HEMT, the temperature at the gate edge on the drain side was 100 °C at a power dissipation of 0.9 W. In contrast, the temperature reached 240 °C at a power dissipation of only 0.7 W for the HEMT on the sapphire substrate. This indicates that the transfer technique can enhance the performance of AlGaN/GaN HEMTs.

  20. Piezo-phototronic effect enhanced UV photodetector based on CuI/ZnO double-shell grown on flexible copper microwire.

    Science.gov (United States)

    Liu, Jingyu; Zhang, Yang; Liu, Caihong; Peng, Mingzeng; Yu, Aifang; Kou, Jinzong; Liu, Wei; Zhai, Junyi; Liu, Juan

    2016-12-01

    In this work, we present a facile, low-cost, and effective approach to fabricate the UV photodetector with a CuI/ZnO double-shell nanostructure which was grown on common copper microwire. The enhanced performances of Cu/CuI/ZnO core/double-shell microwire photodetector resulted from the formation of heterojunction. Benefiting from the piezo-phototronic effect, the presentation of piezocharges can lower the barrier height and facilitate the charge transport across heterojunction. The photosensing abilities of the Cu/CuI/ZnO core/double-shell microwire detector are investigated under different UV light densities and strain conditions. We demonstrate the I-V characteristic of the as-prepared core/double-shell device; it is quite sensitive to applied strain, which indicates that the piezo-phototronic effect plays an essential role in facilitating charge carrier transport across the CuI/ZnO heterojunction, then the performance of the device is further boosted under external strain.

  1. The copper metallome in prokaryotic cells.

    Science.gov (United States)

    Rensing, Christopher; McDevitt, Sylvia Franke

    2013-01-01

    As a trace element copper has an important role in cellular function like many other transition metals. Its ability to undergo redox changes [Cu(I) ↔ Cu(II)] makes copper an ideal cofactor in enzymes catalyzing electron transfers. However, this redox change makes copper dangerous for a cell since it is able to be involved in Fenton-like reactions creating reactive oxygen species (ROS). Cu(I) also is a strong soft metal and can attack and destroy iron-sulfur clusters thereby releasing iron which can in turn cause oxidative stress. Therefore, copper homeostasis has to be highly balanced to ensure proper cellular function while avoiding cell damage.Throughout evolution bacteria and archaea have developed a highly regulated balance in copper metabolism. While for many prokaryotes copper uptake seems to be unspecific, others have developed highly sophisticated uptake mechanisms to ensure the availability of sufficient amounts of copper. Within the cytoplasm copper is sequestered by various proteins and molecules, including specific copper chaperones, to prevent cellular damage. Copper-containing proteins are usually located in the cytoplasmic membrane with the catalytic domain facing the periplasm, in the periplasm of Gram-negative bacteria, or they are secreted, limiting the necessity of copper to accumulate in the cytoplasm. To prevent cellular damage due to excess copper, bacteria and archaea have developed various copper detoxification strategies. In this chapter we attempt to give an overview of the mechanisms employed by bacteria and archaea to handle copper and the importance of the metal for cellular function as well as in the global nutrient cycle.

  2. Analysis of surface coverage of benzotriazole and 6-tolyltriazole mixtures on copper electrodes from surface-enhanced Raman spectra

    Science.gov (United States)

    Loo, B. H.; Ibrahim, A.; Emerson, M. T.

    1998-05-01

    The least-squares method has been used to analyze surface-enhanced Raman spectra of benzotriazole (BTA) and 6-tolyltriazole (6-TTA) mixtures on Cu electrodes. The fractional coverage of these molecules on Cu surfaces is dependent on their absolute solution concentration, and is consistent with an assumed Langmuir adsorption isotherm model. The adsorption equilibrium constant of 6-TTA is found to be about three times that of BTA. This indicates that 6-TTA is more strongly adsorbed on Cu than BTA. The free energy of adsorption for 6-TTA on Cu is 610 cal/mol lower than that for BTA.

  3. Canine Models for Copper Homeostasis Disorders

    Directory of Open Access Journals (Sweden)

    Xiaoyan Wu

    2016-02-01

    Full Text Available Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

  4. Canine Models for Copper Homeostasis Disorders.

    Science.gov (United States)

    Wu, Xiaoyan; Leegwater, Peter A J; Fieten, Hille

    2016-02-04

    Copper is an essential trace nutrient metal involved in a multitude of cellular processes. Hereditary defects in copper metabolism result in disorders with a severe clinical course such as Wilson disease and Menkes disease. In Wilson disease, copper accumulation leads to liver cirrhosis and neurological impairments. A lack in genotype-phenotype correlation in Wilson disease points toward the influence of environmental factors or modifying genes. In a number of Non-Wilsonian forms of copper metabolism, the underlying genetic defects remain elusive. Several pure bred dog populations are affected with copper-associated hepatitis showing similarities to human copper metabolism disorders. Gene-mapping studies in these populations offer the opportunity to discover new genes involved in copper metabolism. Furthermore, due to the relatively large body size and long life-span of dogs they are excellent models for development of new treatment strategies. One example is the recent use of canine organoids for disease modeling and gene therapy of copper storage disease. This review addresses the opportunities offered by canine genetics for discovery of genes involved in copper metabolism disorders. Further, possibilities for the use of dogs in development of new treatment modalities for copper storage disorders, including gene repair in patient-derived hepatic organoids, are highlighted.

  5. High Temperature During Rice Grain Filling Enhances Aspartate Metabolism in Grains and Results in Accumulation of Aspartate-Family Amino Acids and Protein Components

    Directory of Open Access Journals (Sweden)

    Cheng-gang LIANG

    2013-09-01

    Full Text Available Global warming causes the exacerbation of rice growing environment, which seriously affects rice growth and reproduction, and finally results in the decrease of rice yield and quality. We investigated the activities of aspartate metabolism enzymes in grains, and the contents of Aspartate-family amino acids and protein components to further understand the effects of high temperature (HT on rice nutritional quality during rice grain filling. Under HT, the average activities of aspartate aminotransferase (AAT and aspartokinase (AK in grains significantly increased, the amino acid contents of aspartate (Asp, lysine (Lys, threonine (Thr, methionine (Met and isoleucine (Ile and the protein contents of albumin, globulin, prolamin and glutelin also significantly increased. The results indicated that HT enhanced Asp metabolism during rice grain filling and the enhancement of Asp metabolism might play an important role in the increase of Asp-family amino acids and protein components in grains. In case of the partial appraisal of the change of Asp-family amino acids and protein components under HT, we introduced eight indicators (amino acid or protein content, ratio of amino acid or protein, amino acid or protein content per grain and amino acid or protein content per panicle to estimate the effects of HT. It is suggested that HT during rice grain filling was benefit for the accumulation of Asp-family amino acids and protein components. Combined with the improvement of Asp-family amino acid ratio in grains under HT, it is suggested that HT during grain filling may improve the rice nutritional quality. However, the yields of parts of Asp-family amino acids and protein components were decreased under HT during rice grain filling.

  6. Impact of dual inoculation with Rhizobium and PGPR on growth and antioxidant status of Vicia faba L. under copper stress.

    Science.gov (United States)

    Fatnassi, Imen Challougui; Chiboub, Manel; Saadani, Omar; Jebara, Moez; Jebara, Salwa Harzalli

    2015-04-01

    Plant-growth-promoting bacteria (PGPR) may help reduce the toxicity of heavy metals in plants in polluted environments. In this work, the effects of dual inoculation with Rhizobium and PGPR strains on the growth of Vicia faba grown under copper stress were assessed during hydroponic culture. Growth parameters, copper (Cu) accumulation and antioxidant enzyme activities were studied. Copper concentrations above 1mM damaged plant growth, but co-inoculation reduced its harmful effect. Co-inoculation of plants treated with 1mM Cu and 2mM Cu increased the dry weights as compared with Cu-treated and uninoculated plants. However, it decreased copper uptake up to 80% in the roots of 1-mM-Cu-treated plants as compared to non-inoculated control. Copper tolerance in Vicia faba is linked to the activity of antioxidant systems that are modulated by metal concentrations: both superoxide dismutase (SOD) and catalase (CAT) were higher in the presence of Cu; a lower Cu dose of 0.5mM stimulated ascorbate peroxidase (APX) and/or peroxidase (POX) activities in shoots and roots; however in nodules CAT appeared to be the main peroxidase in H2O2 scavenging. The 1mM Cu treatment enhanced SOD, CAT and APX activities in roots and only SOD and POX were activated in shoots. All enzyme activities were inhibited by inoculation of 2mM Cu. The effect of inoculation with copper-accumulating PGPRs and the status of the antioxidant enzyme system were linked to changes in the copper tolerance status of Vicia faba. Our results suggested that Vicia faba inoculation with Rhizobium and PGPR Enterobacter clocae and Pseudomonas sp. could help to alleviate copper stress under hydroponic conditions. This result should be tested under field conditions for soil fertilization and phytostabilisation purposes.

  7. Reduced ABA Accumulation in the Root System is Caused by ABA Exudation in Upland Rice (Oryza sativa L. var. Gaoshan1) and this Enhanced Drought Adaptation.

    Science.gov (United States)

    Shi, Lu; Guo, Miaomiao; Ye, Nenghui; Liu, Yinggao; Liu, Rui; Xia, Yiji; Cui, Suxia; Zhang, Jianhua

    2015-05-01

    Lowland rice (Nipponbare) and upland rice (Gaoshan 1) that are comparable under normal and moderate drought conditions showed dramatic differences in severe drought conditions, both naturally occurring long-term drought and simulated rapid water deficits. We focused on their root response and found that enhanced tolerance of upland rice to severe drought conditions was mainly due to the lower level of ABA in its roots than in those of the lowland rice. We first excluded the effect of ABA biosynthesis and catabolism on root-accumulated ABA levels in both types of rice by monitoring the expression of four OsNCED genes and two OsABA8ox genes. Next, we excluded the impact of the aerial parts on roots by suppressing leaf-biosynthesized ABA with fluridone and NDGA (nordihydroguaiaretic acid), and measuring the ABA level in detached roots. Instead, we proved that upland rice had the ability to export considerably more root-sourced ABA than lowland rice under severe drought, which improved ABA-dependent drought adaptation. The investigation of apoplastic pH in root cells and root anatomy showed that ABA leakage in the root system of upland rice was related to high apoplastic pH and the absence of Casparian bands in the sclerenchyma layer. Finally, taking some genes as examples, we predicted that different ABA levels in rice roots stimulated distinct ABA perception and signaling cascades, which influenced its response to water stress.

  8. Transgenic soybean plants overexpressing O-acetylserine sulfhydrylase accumulate enhanced levels of cysteine and Bowman-Birk protease inhibitor in seeds.

    Science.gov (United States)

    Kim, Won-Seok; Chronis, Demosthenis; Juergens, Matthew; Schroeder, Amy C; Hyun, Seung Won; Jez, Joseph M; Krishnan, Hari B

    2012-01-01

    Soybeans provide an excellent source of protein in animal feed. Soybean protein quality can be enhanced by increasing the concentration of sulfur-containing amino acids. Previous attempts to increase the concentration of sulfur-containing amino acids through the expression of heterologous proteins have met with limited success. Here, we report a successful strategy to increase the cysteine content of soybean seed through the overexpression of a key sulfur assimilatory enzyme. We have generated several transgenic soybean plants that overexpress a cytosolic isoform of O-acetylserine sulfhydrylase (OASS). These transgenic soybean plants exhibit a four- to tenfold increase in OASS activity when compared with non-transformed wild-type. The OASS activity in the transgenic soybeans was significantly higher at all the stages of seed development. Unlike the non-transformed soybean plants, there was no marked decrease in the OASS activity even at later stages of seed development. Overexpression of cytosolic OASS resulted in a 58-74% increase in protein-bound cysteine levels compared with non-transformed wild-type soybean seeds. A 22-32% increase in the free cysteine levels was also observed in transgenic soybeans overexpressing OASS. Furthermore, these transgenic soybean plants showed a marked increase in the accumulation of Bowman-Birk protease inhibitor, a cysteine-rich protein. The overall increase in soybean total cysteine content (both free and protein-bound) satisfies the recommended levels required for the optimal growth of monogastric animals.

  9. Enhancement of β-amyloid oligomer accumulation after intracerebroventricular injection of streptozotocin, which involves central insulin signaling in a transgenic mouse model.

    Science.gov (United States)

    Lin, Fangju; Jia, Jianping; Qin, Wei

    2014-11-12

    The β-amyloid (Aβ) oligomer rather than fibrillar Aβ has become the important focus of recent studies on the pathogenesis of Alzheimer's disease (AD). Insulin signaling plays important roles in cognitive disease, such as AD. However, in-vivo evidence for the link between central insulin signaling and the Aβ oligomer are lacking, and the mechanisms underlying the effect of central insulin signaling on AD are still elusive. Our team has established the Presenilin-1 Val97Leu mutant transgenic (PS1V97L) AD mouse model with the intraneuronal Aβ oligomer as the potential initiator for other pathologies, but without extracellular amyloid plaque formation. Using this model, we investigated the roles of disturbed central insulin signaling induced by intracerebroventricular injection of streptozotocin (STZ) in the progression of AD. We observed that PS1V97L mice after intracerebroventricular injection of STZ showed increased Aβ oligomer accumulation and aggravated spatial learning and memory deficit in the absence of diabetes symptoms. Furthermore, STZ administration inhibited the activation of the insulin receptor and enhanced the activation of c-Jun NH2-terminal kinase, which was accompanied by increased production of carboxy-terminal fragments from the amyloid precursor protein, in the brain of PS1V97L mice. Overall, our study provided in-vivo evidence for a role of central insulin signaling in AD progression.

  10. Tumor Suppressor Pten Inhibits Nuclear Accumulation of β-Catenin and T Cell/Lymphoid Enhancer Factor 1–Mediated Transcriptional Activation

    Science.gov (United States)

    Persad, Sujata; A.Troussard, Armelle; McPhee, Timothy R.; Mulholland, David J.; Dedhar, Shoukat

    2001-01-01

    β-Catenin is a protein that plays a role in intercellular adhesion as well as in the regulation of gene expression. The latter role of β-catenin is associated with its oncogenic properties due to the loss of expression or inactivation of the tumor suppressor adenomatous polyposis coli (APC) or mutations in β-catenin itself. We now demonstrate that another tumor suppressor, PTEN, is also involved in the regulation of nuclear β-catenin accumulation and T cell factor (TCF) transcriptional activation in an APC-independent manner. We show that nuclear β-catenin expression is constitutively elevated in PTEN null cells and this elevated expression is reduced upon reexpression of PTEN. TCF promoter/luciferase reporter assays and gel mobility shift analysis demonstrate that PTEN also suppresses TCF transcriptional activity. Furthermore, the constitutively elevated expression of cyclin D1, a β-catenin/TCF–regulated gene, is also suppressed upon reexpression of PTEN. Mechanistically, PTEN increases the phosphorylation of β-catenin and enhances its rate of degradation. We define a pathway that involves mainly integrin-linked kinase and glycogen synthase kinase 3 in the PTEN-dependent regulation of β-catenin stability, nuclear β-catenin expression, and transcriptional activity. Our data indicate that β-catenin/TCF–mediated gene transcription is regulated by PTEN, and this may represent a key mechanism by which PTEN suppresses tumor progression. PMID:11402061

  11. Enhanced-electrokinetic remediation of copper-pyrene co-contaminated soil with different oxidants and pH control.

    Science.gov (United States)

    Cang, Long; Fan, Guang-Ping; Zhou, Dong-Mei; Wang, Quan-Ying

    2013-02-01

    Electrokinetic (EK) remediation has potential to simultaneously remove heavy metals and organic compounds from soil, but the removal percent of these pollutants is very low in general if no enhancing treatment is applied. This study developed a new enhanced-EK remediation technology to decontaminate a heavy metal-organic compound co-contaminated soil by applying different oxidants and pH control. A red soil was used as a model clayed soil, and was spiked with pyrene and Cu at about 500 mg kg(-1) for both to simulate real situation. Bench-scale EK experiments were performed using four oxidants (H(2)O(2), NaClO, KMnO(4), and Na(2)S(2)O(8)) and controlling electrolyte pH at 3.5 or 10. After the treatments with 1.0 V cm(-1) of voltage gradient for 335 h, soil pH, electrical conductivity, and the concentrations and chemical fractionations of soil pyrene and Cu were analyzed. The results showed that there was significant migration of pyrene and Cu from the soil, and the removal percent of soil pyrene and Cu varied in the range of 30-52% and 8-94%, respectively. Low pH favoured the migration of soil Cu, while KMnO(4) was the best one for the degradation of pyrene among the tested oxidants, although it unfortunately prevented the migration of soil Cu by forming Cu oxide. Application of Na(2)S(2)O(8) and to control the catholyte pH at 3.5 were found to be the best operation conditions for decontaminating the Cu-pyrene co-contaminated soil.

  12. Enhanced photoelectrocatalytic decomposition of copper cyanide complexes and simultaneous recovery of copper with a Bi2MoO6 electrode under visible light by EDTA/K4P2O7.

    Science.gov (United States)

    Zhao, Xu; Zhang, Juanjuan; Qiao, Meng; Liu, Huijuan; Qu, Jiuhui

    2015-04-07

    Simultaneous photoelectrocatalytic (PEC) oxidation of cyanides and recovery of copper in a PEC reactor with a Bi(2)MoO(6) photoanode was investigated at alkaline conditions under visible light irradiation. The surface variation of the Bi(2)MoO(6) photoanode and titanium cathode was characterized. The Cu mass distribution onto the anode, in the solution, and onto the cathode was fully investigated. In the individual PEC oxidation of copper cyanides, the formation of a black copper oxide on the anode occurred. By keeping the initial cyanide concentration at 0.01 mM, the effect of EDTA/K(4)P(2)O(7) was examined at different molar ratios of EDTA/K(4)P(2)O(7) to cyanide. It was indicated that the oxidation of cyanides increased and simultaneous copper electrodeposition with zero value onto the cathode was feasible at pH 11. Under the optimal conditions, the total cyanide concentration was lowered from 250 to 5.0 mg/L, and the Cu recovery efficiency deposited onto the cathode was higher than 90%. Cyanate was the only product. The role of the photogenerated hole in the oxidation of cyanide ions was confirmed.

  13. Similar stress responses are elicited by copper and ultraviolet radiation in the aquatic plant Lemna gibba: implication of reactive oxygen species as common signals.

    Science.gov (United States)

    Babu, T Sudhakar; Akhtar, Tariq A; Lampi, Mark A; Tripuranthakam, Sridevi; Dixon, D George; Greenberg, Bruce M

    2003-12-01

    Metals and ultraviolet (UV) radiation are two environmental stressors that can cause damage to plants. These two types of stressors often impact simultaneously on plants and both are known to promote reactive oxygen species (ROS) production. However, little information is available on the potential parallel stress responses elicited by metals and UV radiation. Using the aquatic plant Lemna gibba, we found that copper and simulated solar radiation (SSR, a light source containing photosynthetically active radiation (PAR) and UV radiation) induced similar responses in the plants. Both copper and SSR caused ROS formation. The ROS levels were higher when copper was combined with SSR than when applied with PAR. Higher concentrations of copper plus PAR caused toxicity as monitored by diminished growth and chlorophyll content. This toxicity was more pronounced when copper was combined with SSR. Because the generation of ROS was also higher when copper was combined with SSR, we attributed this enhanced toxicity to elevated levels of ROS. In comparison to PAR-grown plants, SSR treated plants exhibited elevated levels of superoxide dismutase (SOD) and glutathione reductase (GR). These enzyme levels were further elevated under both PAR and SSR when copper was added at concentrations that generated ROS. Interestingly, copper treatment in the absence of SSR (i.e. copper plus PAR) induced synthesis of the same flavonoids as those observed in SSR without copper. Finally, addition of either dimethyl thiourea or GSH (two common ROS scavengers) lowered in vivo ROS production, alleviated toxicity and diminished induction of GR as well as accumulation of UV absorbing compounds. Thus, the potential of ROS being a common signal for acclimation to stress by both copper and UV can be considered.

  14. Highly sensitive determination of mercury using copper enhancer by diamond electrode coupled with sequential injection–anodic stripping voltammetry

    Energy Technology Data Exchange (ETDEWEB)

    Chaiyo, Sudkate [Department of Chemistry, Faculty of Science, Srinakharinwirot University (Thailand); Chailapakul, Orawon [Department of Chemistry, Faculty of Science, Chulalongkorn University (Thailand); Center for Petroleum, Petrochemicals, and Advanced Materials, Chulalongkorn University (Thailand); Siangproh, Weena, E-mail: weena@swu.ac.th [Department of Chemistry, Faculty of Science, Srinakharinwirot University (Thailand)

    2014-12-10

    Highlights: • Highly sensitive determination of Hg(II) using SI–ASV-BDD was achieved. • Electrochemical detection of Hg(II) using Cu(II) enhancer was accomplished. • LOD and LOQ were found to be very low at 40.0 ppt and 135.0 ppt. • This method was successfully applied for determination of Hg(II) in real samples. - Abstract: A highly sensitive determination of mercury in the presence of Cu(II) using a boron-doped diamond (BDD) thin film electrode coupled with sequential injection–anodic stripping voltammetry (SI–ASV) was proposed. The Cu(II) was simultaneously deposited with Hg(II) in a 0.5 M HCl supporting electrolyte by electrodeposition. In presence of an excess of Cu(II), the sensitivity for the determination of Hg(II) was remarkably enhanced. Cu(II) and Hg(II) were on-line deposited onto the BDD electrode surface at −1.0 V (vs. Ag/AgCl, 3 M KCl) for 150 s with a flow rate of 14 μL s{sup −1}. An anodic stripping voltammogram was recorded from −0.4 V to 0.25 V using a frequency of 60 Hz, an amplitude of 50 mV, and a step potential of 10 mV at a stopped flow. Under the optimal conditions, well-defined peaks of Cu(II) and Hg(II) were found at −0.25 V and +0.05 V (vs. Ag/AgCl, 3 M KCl), respectively. The detection of Hg(II) showed two linear dynamic ranges (0.1–30.0 ng mL{sup −1} and 5.0–60.0 ng mL{sup −1}). The limit of detection (S/N = 3) obtained from the experiment was found to be 0.04 ng mL{sup −1}. The precision values for 10 replicate determinations were 1.1, 2.1 and 2.9% RSD for 0.5, 10 and 20 ng mL{sup −1}, respectively. The proposed method has been successfully applied for the determination of Hg(II) in seawater, salmon, squid, cockle and seaweed samples. A comparison between the proposed method and an inductively coupled plasma optical emission spectrometry (ICP-OES) standard method was performed on the samples, and the concentrations obtained via both methods were in agreement with the certified values of Hg

  15. Effects of Glutathione on Alleviation of Copper Toxicity and Its Correlation with Accumulation of Nitrogen,Sulfur and Phosphorus in Wheat Seedlings%谷胱甘肽对小麦幼苗铜毒害的缓解作用及其与氮、硫、磷积累的相关性

    Institute of Scientific and Technical Information of China (English)

    彭向永; 常宝; 徐术人; 吴巍莉; 石磊

    2012-01-01

    采用水培法,对外源谷胱甘肽( GSH)缓解小麦幼苗铜毒害及其与氮、硫、磷等元素积累的相关性进行了研究.结果表明,Cu处理(T0组)显著抑制小麦幼苗的生长发育,导致根长、茎叶长、生物量、叶绿素和类胡萝卜素含量以及氮元素积累量下降,诱导了植株蛋白质、内源GSH含量以及硫、磷元素积累量上升.随施用外源GSH浓度的升高,GSH处理(T1、T2、T3组)的小麦幼苗茎叶长、根长、生物量,叶绿素a、b和类胡萝卜素含量、蛋白质含量先上升后下降,内源GSH含量以及氮、硫、磷等营养元素积累量持续上升;其中.T2组小麦幼苗的各项指标与T0组差异均达到显著水平(P<0.05),与对照组(CK)无显著差异.外源GSH促进了植株对铜离子的吸收、转运和积累,而外源和内源GSH均与铜胁迫下小麦幼苗氮、硫、磷等营养元素的积累呈极显著正相关(P<0.01),其中以T2处理组缓解小麦幼苗铜毒害的作用最显著.%The effects of exogenous glutathione on alleviation of copper toxicity and its correlation with contents of nitrogen, sulfur and phosphorus in wheat seedlings stressed by copper sulfate were studied in a hydroponic culture. The results indicated that wheat seedlings growth, stem and root length, biomass, chlorophyll and earotenoids contents, nitrogen accumulation were inhibited by CuSO4-7H2O treatment at 150 mg·L-1 concentration, whereas protein, endogenous GSH, sulfur and phosphorus contents were raised. The length of stem and root, biomass, chlorophyll a, b, earotenoids and protein contents increased with the increase of exogenous GSH until the GSH was 2.5 mmol · L -1, and then decreased. Meanwhile, endogenous GSH content as well as nitrogen, sulfur, phosphorus accumulation rised up. There was a significant difference between T2 and TO treatment, but there was no such difference with control. In general, exogenous GSH could promote absorbing, transporting, and

  16. Enhanced visible light photocatalytic activity of copper-doped titanium oxide-zinc oxide heterojunction for methyl orange degradation

    Science.gov (United States)

    Dorraj, Masoumeh; Alizadeh, Mahdi; Sairi, Nor Asrina; Basirun, Wan Jefrey; Goh, Boon Tong; Woi, Pei Meng; Alias, Yatimah

    2017-08-01

    A novel Cu-doped TiO2 coupled with ZnO nanoparticles (Cu-TiO2/ZnO) was prepared by sol-gel method and subsequent precipitation for methyl orange (MO) photodegradation under visible light irradiation. The compositions and shapes of the as-prepared Cu-TiO2/ZnO nanocomposites were characterized by photoluminescence spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, UV-vis diffuse reflectance spectra and Brunauer-Emmett-Teller adsorption isotherm techniques. The Cu-TiO2/ZnO nanocomposites showed considerably higher photocatalytic activity for MO removal from water under visible light irradiation than that of single-doped semiconductors. The effects of Cu-TiO2 and ZnO mass ratios on the photocatalytic reaction were also studied. A coupling percentage of 30% ZnO exhibited the highest photocatalytic activity. The enhanced photocatalytic activity of the Cu-TiO2/ZnO nanocomposites was mainly attributed to heterojunction formation, which allowed the efficient separation of photoinduced electron-hole pairs at the interface. Moreover, these novel nanocomposites could be recycled during MO degradation in a three-cycle experiment without evident deactivation, which is particularly important in environmental applications.

  17. A comparative study of the inhibition effects of benzotriazole and 6-aniline-1,3,5-triazine-2,4-dithiol monosodium salt on the corrosion of copper by potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques

    Science.gov (United States)

    Zhou, Guoding; Cai, Shengmin; Song, Liqun; Yang, Huaquan; Fujishima, A.; Ibrahim, A.; Lee, Y. G.; Loo, B. H.

    1991-11-01

    The inhibition effects of benzotriazole (BTA) and 6-aniline-1,3,5-triazine-2,4-dithiol (ATD) monosodium salt on copper corrosion have been studied by the potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques. The polarization resistance Rp increases with the concentration of either BTA or ATD. From the plots of the phase shift θ versus logarithm of the frequency, it is found that θ is close to 90° after the copper electrode is immersed for a long period of time in BTA-containing solution which indicates the behavior of an ideal capacitor. In ATD-containing solutions, θ is close to 45 ° which shows the appearance of a Warburg impedance for a diffusion process. Surface-enhanced Raman spectroscopic studies of the competitive adsorption of BTA and ATD on copper surfaces indicate that BTA adsorbs better than ATD. Based on these results, it is concluded that the inhibition action of BTA is better than that of ATD.

  18. Acumulación de cobre en una comunidad vegetal afectada por contaminación minera en el valle de Puchuncaví, Chile central Copper accumulation in a plant community affected by mining contamination in Puchuncaví valley, central Chile

    Directory of Open Access Journals (Sweden)

    ISABEL GONZÁLEZ

    2008-06-01

    Full Text Available Las especies hiperacumuladoras son capaces de acumular más de 1.000 mg kg-1 de metal en su biomasa aérea y son útiles en procesos de fitoextracción de metales en suelos contaminados por actividades mineras. Con el fin de identificar especies hiperacumuladoras representativas de las condiciones chilenas, se realizó una prospección dentro de la diversidad vegetal en el área afectada por las emisiones de la Fundición Ventanas (90-900 mg kg-1 de Cu total en suelos, así como en un área cercana a una pila de escorias de fundición (500-3.000 mg kg-1 de Cu total en suelos. Se determinaron las concentraciones de Cu en la biomasa aérea de las plantas. Los resultados indican que dentro de la diversidad del sitio existen al menos veintidós especies pseudometalofitas, es decir, ecotipos de especies comunes que son capaces de tolerar concentraciones de cobre en el suelo que para una planta normal serían tóxicas. Las especies fueron clasificadas según su concentración de cobre y mostraron en su mayoría media (200-600 mg kg-1 o baja (Hyperaccumulator plants species are capable of accumulating more than 1,000 mg Cu kg-1 in their shoots and are useful for metal phytoextraction in soils contaminated by mining activities. To identify the hyperaccumulator plants representative of the Chilean conditions, we carried out a survey of plant diversity in the área affected by the emissions of the Ventanas smelter (90-900 mg kg-1 of total Cu in soils and in a nearby área cióse to a smelter slug pile (500-3,000 mg kg-1 of total Cu in soils. Copper concentrations in the shoots of the studied plants were determined. Results indicate that there were at least twenty-two pseudometallophyte species, i.e., ecotypes of common species capable to tolérate concentrations of Cu in the soil that would be toxic for a normal plant. The species were classified by their copper accumulation and nearly all exhibited médium (200-600 mg kg-1 or low (< 200 mg kg-1

  19. Copper-induced response of physiological parameters and antioxidant enzymes in the aquatic macrophyte Potamogeton pusillus

    Energy Technology Data Exchange (ETDEWEB)

    Monferran, Magdalena V.; Sanchez Agudo, Jose A. [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica - CIBICI, Medina Allende Esq., Haya de la Torre, Ciudad Universitaria, 5000 Cordoba (Argentina); Pignata, Maria L. [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Exactas, Fisicas y Naturales - IMBIV, Ciudad Universitaria, 5000 Cordoba (Argentina); Wunderlin, Daniel A., E-mail: dwunder@fcq.unc.edu.a [Universidad Nacional de Cordoba - CONICET, Facultad de Ciencias Quimicas, Dto. Bioquimica Clinica - CIBICI, Medina Allende Esq., Haya de la Torre, Ciudad Universitaria, 5000 Cordoba (Argentina)

    2009-08-15

    Bioaccumulation and toxicity of copper was evaluated on Potamogeton pusillus L. The effect of copper (5-100 mug L{sup -1}) applied for several days was assessed by measuring changes in the chlorophyll's, phaeophytin's, malondialdehyde, electrical conductivity, glutathione peroxidase (GPX), glutathione reductase (GR) and guaiacol peroxidase (POD) activities. Plants accumulated copper with a maximum of 162 mug g{sup -1} dw after 7-days exposure at 100 mug L{sup -1}, however most of the metal was accumulated after 1-day exposure. The toxic effect caused by Cu was evident by the reduction of photosynthetic pigments, increase of malondialdehyde and electrical conductivity. P. pusillus shows Cu-induced oxidative stress by modulating antioxidant enzymes like GPX, GR and POD. Antioxidant enzymes activity increased significantly after exposure to 40 mug L{sup -1} during 24 h, followed by a drop at longer times. Thus, P. pusillus is proposed as a good biomonitor for the assessment of metal pollution in aquatic ecosystems. - The tolerance of Potamogeton pusillus to copper largely depends on the enhanced activity of its antioxidant system, showing that a decrease on its activity favored oxidative stress and cell damage.

  20. Intracellular accumulation of mercury enhances P450 CYP1A1 expression and Cl- currents in cultured shark rectal gland cells.

    Science.gov (United States)

    Ke, Qingen; Yang, Yinke; Ratner, Martha; Zeind, John; Jiang, Canwen; Forrest, John N; Xiao, Yong-Fu

    2002-04-21

    The effects of acute and subchronic exposure to mercury on the Cl- current (ICl) were investigated in cultured shark rectal gland (SRG) cells. The effects of intracellular accumulation of mercury on cytochrome P450 (P450) were also assessed. Bath perfusion of a cocktail solution containing forskolin, 1-isobutyl-3-methylxanthine, and 8-bromoadenosine monophosphate enhanced ICl. Addition of 10 microM HgCl2 significantly inhibited the cAMP-activated ICl (p mercury on ICl. In contrast, incubation of SRG cells with 10 microM HgCl2 for 48 hrs markedly increased ICl (p mercury-incubated increase in ICl. The P450-mediated metabolite of arachidonic acid, 11,12-epoxyeicosatrienoic acid (11,12-EET), significantly increased ICl. However, application of 11,12-dihydroxyeicosatrienoic acid (11,12-DHT) did not alter ICl. Mercury incubation for 48 hrs did not alter the protein expression of Cl- channels, but caused an induction of CYP1A1 in cultured SRG cells. In addition, co-incubation of SRG cells with mercury and the P450 inhibitor clotrimazole prevented the mercury-incubated increase in ICl. Our results demonstrate that acute and subchronic application of mercury has opposing effects on ICl in cultured SRG cells. The acute effect of mercury on ICl may result from mercury blockade of Cl- channels. The subchronic effect of mercury on ICl may be due to an induction of P450 CYP1A1 and its mediated metabolites, but not due to an over-expression of Cl- channels.

  1. Expression of the ZNT1 Zinc Transporter from the Metal Hyperaccumulator Noccaea caerulescens Confers Enhanced Zinc and Cadmium Tolerance and Accumulation to Arabidopsis thaliana.

    Science.gov (United States)

    Lin, Ya-Fen; Hassan, Zeshan; Talukdar, Sangita; Schat, Henk; Aarts, Mark G M

    2016-01-01

    Prompt regulation of transition metal transporters is crucial for plant zinc homeostasis. NcZNT1 is one of such transporters, found in the metal hyperaccumulator Brassicaceae species Noccaea caerulescens. It is orthologous to AtZIP4 from Arabidopsis thaliana, an important actor in Zn homeostasis. We examined if the NcZNT1 function contributes to the metal hyperaccumulation of N. caerulescens. NcZNT1 was found to be a plasma-membrane located metal transporter. Constitutive overexpression of NcZNT1 in A. thaliana conferred enhanced tolerance to exposure to excess Zn and Cd supply, as well as increased accumulation of Zn and Cd and induction of the Fe deficiency response, when compared to non-transformed wild-type plants. Promoters of both genes were induced by Zn deficiency in roots and shoots of A. thaliana. In A. thaliana, the AtZIP4 and NcZNT1 promoters were mainly active in cortex, endodermis and pericycle cells under Zn deficient conditions. In N. caerulescens, the promoters were active in the same tissues, though the activity of the NcZNT1 promoter was higher and not limited to Zn deficient conditions. Common cis elements were identified in both promoters by 5' deletion analysis. These correspond to the previously determined Zinc Deficiency Responsive Elements found in A. thaliana to interact with two redundantly acting transcription factors, bZIP19 and bZIP23, controlling the Zn deficiency response. In conclusion, these results suggest that NcZNT1 is an important factor in contributing to Zn and Cd hyperaccumulation in N. caerulescens. Differences in cis- and trans-regulators are likely to account for the differences in expression between A. thaliana and N. caerulescens. The high, constitutive NcZNT1 expression in the stele of N. caerulescens roots implicates its involvement in long distance root-to-shoot metal transport by maintaining a Zn/Cd influx into cells responsible for xylem loading.

  2. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierrae from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour. Copyright ?? 2011 British Lichen Society.

  3. Copper localization, elemental content, and thallus colour in the copper hyperaccumulator lichen Lecanora sierra from California

    Science.gov (United States)

    Purvis, O.W.; Bennett, J.P.; Spratt, J.

    2011-01-01

    An unusual dark blue-green lichen, Lecanora sierrae, was discovered over 30 years ago by Czehura near copper mines in the Lights Creek District, Plumas County, Northern California. Using atomic absorption spectroscopy, Czehura found that dark green lichen samples from Warren Canyon contained 4% Cu in ash and suggested that its colour was due to copper accumulation in the cortex. The present study addressed the hypothesis that the green colour in similar material we sampled from Warren Canyon in 2008, is caused by copper localization in the thallus. Optical microscopy and electron microprobe analysis of specimens of L. sierrae confirmed that copper localization took place in the cortex. Elemental analyses of L. sierrae and three other species from the same localities showed high enrichments of copper and selenium, suggesting that copper selenates or selenites might occur in these lichens and be responsible for the unusual colour.

  4. Trace copper levels in the drinking water, but not zinc or aluminum influence CNS Alzheimer-like pathology.

    Science.gov (United States)

    Sparks, D L; Friedland, R; Petanceska, S; Schreurs, B G; Shi, J; Perry, G; Smith, M A; Sharma, A; Derosa, S; Ziolkowski, C; Stankovic, G

    2006-01-01

    Mounting evidence suggests copper may influence the progression of Alzheimer's disease by reducing clearance of the amyloid beta protein (Abeta) from the brain. Previous experiments show that addition of only 0.12 PPM copper (one-tenth the Environmental Protection Agency Human consumption limits) to distilled water was sufficient to precipitate the accumulation of Abeta in the brains of cholesterol-fed rabbits (1). Here we report that addition of copper to the drinking water of spontaneously hypercholesterolemic Watanabe rabbits, cholesterol-fed beagles and rabbits, PS1/APP transgenic mice produced significantly enhanced brain levels of Abeta. In contrast to the effects of copper, we found that aluminum- or zinc-ion-supplemented distilled water did not have a significant effect on brain Ab accumulation in cholesterol-fed rabbits. We also report that administration of distilled water produced a reduction in the expected accumulation of Ab in three separate animal models. Collectively, these data suggest that water quality may have a significant influence on disease progression and Ab neuropathology in AD.

  5. Copper intoxication inhibits aerobic nucleotide synthesis in Streptococcus pneumoniae

    Science.gov (United States)

    Johnson, Michael D. L.; Kehl-Fie, Thomas E.; Rosch, Jason W.

    2015-01-01

    Copper is universally toxic in excess, a feature exploited by the human immune system to facilitate bacterial clearance. The mechanism of copper intoxication remains unknown for many bacterial species. Here, we demonstrate that copper toxicity in Streptococcus pneumoniae is independent from oxidative stress but, rather, is the result of copper inhibiting the aerobic dNTP biosynthetic pathway. Furthermore, we show that copper-intoxicated S. pneumoniae is rescued by manganese, which is an essential metal in the aerobic nucleotide synthesis pathway. These data provide insight into new targets to enhance copper-mediated toxicity during bacterial clearance. PMID:25730343

  6. Jiangxi Hengfeng Nanfang Copper Reconstruction & Extension Project Signed

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    <正>The reconstruction & extension project (phase II) of Nanfang Copper has been recently signed. With an investment of RMB 0.8 billion, the project is expected to produce 50,000 tons of anode copper and electrolytic copper respectively per year with output value of RMB 3 billion, and will further enhance development

  7. Abnormal Copper Homeostasis: Mechanisms and Roles in Neurodegeneration

    Directory of Open Access Journals (Sweden)

    Mario Manto

    2014-06-01

    Full Text Available As a cofactor of proteins and enzymes involved in critical molecular pathways in mammals and low eukaryotes, copper is a transition metal essential for life. The intra-cellular and extra-cellular metabolism of copper is under tight control, in order to maintain free copper concentrations at very low levels. Copper is a critical element for major neuronal functions, and the central nervous system is a major target of disorders of copper metabolism. Both the accumulation of copper and copper deficiency are associated with brain dysfunction. The redox capacities of free copper, its ability to trigger the production of reactive oxygen species and the close relationships with the regulation of iron and zinc are remarkable features. Major advances in our understanding of the relationships between copper, neuronal functions and neurodegeneration have occurred these last two decades. The metabolism of copper and the current knowledge on the consequences of copper dysregulation on brain disorders are reviewed, with a focus on neurodegenerative diseases, such as Wilson’s disease, Alzheimer’s disease and Parkinson’s disease. In vitro studies, in vivo experiments and